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2009 Vol. 29, No. 01
Published: 2009-01-01

 
       光谱学与光谱分析
1 Properties of Energy Transfer in Two Host Materials Doped with Ir(ppy)3 and Rubrene
LI Yan-rui1,ZHAO Su-ling1*,YANG Shao-peng2,XU Zheng1,ZHANG Fu-jun1,SONG Dan-dan1,XU Xu-rong1
DOI: 10.3964/j.issn.1000-0593(2009)01-0001-05
The devices with phosphorescent material tris(2-phenylpyridine)iridium [Ir(ppy)3] and fluorescent material 5,6,11,12-tetraphenylnaphthacene [Rubrene] as dopants in two kinds of host were constructed in the present study. Respectively, the two kinds of host are polyvinylcarbazole [PVK] and 4,4’-N,N-dicarbazole-biphenyl . We studied the properties of energy transfer between host materials and dopants. Firstly, the absorption and photoluminescence spectra of PVK, CBP, Ir(ppy)3 and Rubrene were measured. The spectral overlap between the photoluminescence of PVK and the absorption spectrum of Ir(ppy)3 is larger than that of Rubrene. The result of the spectral overlap for CBP is the same as PVK. It was shown that the energy transfer from the two host materials to Ir(ppy)3 is stronger than that to Rubrene. In addition, the energy transfer from Ir(ppy)3 to Rubrene is possible according to their absorption and photoluminescence spectra. We compared the electroluminescence properties of different devices. In device1 of ITO/PVK∶Rubrene∶Ir(ppy)3(100∶5∶x)/BCP(10 nm)/Alq3(20 nm)/Al and device 2 ITO/CBP∶Rubrene∶Ir(ppy)3(100∶5∶x)/BCP(10 nm)/Alq3(20 nm)/Al(x=0, 3), under the same DC bias, the electroluminescence results show that energy transfer from host to Rubrene through Ir(ppy)3 is the main mechanism. And energy transfer is much more efficient in CBP as host than in PVK. In addition, at the same voltage, the light power of the device doped with Ir(ppy)3 and Rubrene is obviously stronger than that of the device doped with Rubrene only. When the concentration of Ir(ppy)3 increases, the light power decreases at the same voltage, and the effect of concentration quenching is enhanced.
2009 Vol. 29 (01): 1-5 [Abstract] ( 1624 ) PDF (1748 KB)  ( 1023 )
6 Measurement of the Rb[5P3/2(F′=4)] Hyperfine Level Nonradiative Decay Rate Near a Metallic Film with Laser Retrofluoresence Spectroscopy
LIU Jing1,2,XIN Jing-tao1,DAI Kang1,SHEN Yi-fan1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0006-04
The signals of the hyperfine 85Rb[5P3/2(F′=2,3,4)→5S1/2(F=3)] transition lines in a diode laser induced retrofluorescence spectrum at the interface between glass and Rb vapor were experimentally identified and investigated. The glass-vapor interface was considered as two distinct regions, a wavelength-thickness vapor layer joined to the surface and a more remote vapor region. The first region was analyzed as a spectral filter that annihilates the absorbed photons and the second one as a rich spectral light source. The experimental setup is described. A Rb reference cell (T=293 K) was used. A part of the laser beam scanned the 5S1/2(F=3)→5P3/2(F′=2,3,4) transition. The Doppler broadened absorption profile (FWHM=510 MHz) was determined. The laser detuning of the profile-center relative to the F=3→F′=4 transition was about 70 MHz. Another laser beam was directed to the entrance cell window. The resonant retrofluorescence Sob(νL) as a function of laser detuning for a cell temperature ~130 ℃ and laser power 0.4 mW was obtained. We can extract the experimental signal snexP(νL) originating from the near-field region by subtracting signal ST(νL) originating from the far-field region from the total experiment signal Sob(νL). A fit of the normalized profile of the data corresponding to the spectral band centered on the F′=4→F=3 hyperfine transition line was obtained by using a Lorentzian distribution function with ΓRF=50 MHz full width at half-maximum. The role played by different relaxation processes contributing to the retrofluorescent atomic linewidth was characterized. The authors summed up the corresponding spectral broadening and obtained the relation ΓRFΓn+Γcoll+Γnr,where Γcoll is the resonance collisional broadening of the hyperfine line, and Γnr is an additional broadening induced by the nonradiative energy-transfer phenomena of the excited atoms near the cell window surface. To evaluate Γcoll,we used the relation ΓcollγRb-RbN, where γRb-Rb is line broadening parameter, and N is Rb atom number density. The effective nonradiative relaxation rate of the 5P3/2(F′=4) energy hyperfine level was estimated to be AnrF′=4→F=3=2.4×108 s-1. The value of Anr seems relatively large compared to the spontaneous emission rate A(5P3/2→5P1/2)=1.4×107 s-1.
2009 Vol. 29 (01): 6-9 [Abstract] ( 2570 ) PDF (1259 KB)  ( 668 )
10 Open-Path Online Monitoring of Ambient Atmospheric CO2 Based on Laser Absorption Spectrum
HE Ying,ZHANG Yu-jun,KAN Rui-feng,XIA Hui,GENG Hui,RUAN Jun,WANG Min,CUI Xiao-juan,LIU Wen-qing
DOI: 10.3964/j.issn.1000-0593(2009)01-0010-04
With the conjunction of tunable diode laser absorption spectroscopy technology(TDLAS) and the open long optical path technology,the system designing scheme of CO2 on-line monitoring based on near infrared tunable diode laser absorption spectroscopy technology was discussed in detail, and the instrument for large-range measurement was set up. By choosing the infrared absorption line of CO2 at 1.57 μm whose line strength is strong and suitable for measurement, the ambient atmospheric CO2 was measured continuously with a 30 s temporal resolution at an suburb site in the autumn of 2007. The diurnal atmospheric variations of CO2 and continuous monitoring results were presented. The results show that the variation in CO2 concentration has an obvious diurnal periodicity in suburb where the air is free of interference and contamination. The general characteristic of diurnal variation is that the concentration is low in the daytime and high at night,so it matches the photosynthesis trend. The instrument can detect gas concentration online with high resolution, high sensitivity, high precision, short response time and many other advantages,the monitoring requires no gas sampling, the calibration is easy,and the detection limit is about 4.2×10-7. It has been proved that the system and measurement project are feasible, so it is an effective method for gas flux continuous online monitoring of large range in ecosystem based on TDLAS technology.
2009 Vol. 29 (01): 10-13 [Abstract] ( 2132 ) PDF (1311 KB)  ( 788 )
14 A Hyperspectral Subpixel Target Detection Method Based on Inverse Least Squares Method
LI Qing-bo,NIE Xin,ZHANG Guang-jun*
DOI: 10.3964/j.issn.1000-0593(2009)01-0014-06
In the present paper, an inverse least square (ILS) method combined with the Mahalanobis distance outlier detection method is discussed to detect the subpixel target from the hyperspectral image. Firstly, the inverse model for the target spectrum and all the pixel spectra was established, in which the accurate target spectrum was obtained previously, and then the SNV algorithm was employed to preprocess each original pixel spectra separately. After the pretreatment, the regressive coefficient of ILS was calculated with partial least square (PLS) algorithm. Each point in the vector of regressive coefficient corresponds to a pixel in the image. The Mahalanobis distance was calculated with each point in the regressive coefficient vector. Because Mahalanobis distance stands for the extent to which samples deviate from the total population, the point with Mahalanobis distance larger than the 3σ was regarded as the subpixel target. In this algorithm, no other prior information such as representative background spectrum or modeling of background is required, and only the target spectrum is needed. In addition, the result of the detection is insensitive to the complexity of background. This method was applied to AVIRIS remote sensing data. For this simulation experiment, AVIRIS remote sensing data was free downloaded from the NASA official websit, the spectrum of a ground object in the AVIRIS hyperspectral image was picked up as the target spectrum, and the subpixel target was simulated though a linear mixed method. The comparison of the subpixel detection result of the method mentioned above with that of orthogonal subspace projection method (OSP) was performed. The result shows that the performance of the ILS method is better than the traditional OSP method. The ROC (receive operating characteristic curve) and SNR were calculated, which indicates that the ILS method possesses higher detection accuracy and less computing time than the OSP algorithm.
2009 Vol. 29 (01): 14-19 [Abstract] ( 680 ) PDF (1970 KB)  ( 523 )
20 Analysis and Experimental Verification of Sensitivity and SNR of Laser Warning Receiver
ZHANG Ji-long, WANG Ming, TIAN Er-ming, LI Xiao, WANG Zhi-bin, ZHANG Yue
DOI: 10.3964/j.issn.1000-0593(2009)01-0020-04
In order to countermeasure increasingly serious threat from hostile laser in modern war, it is urgent to do research on laser warning technology and system, and the sensitivity and signal to noise ratio (SNR) are two important performance parameters in laser warning system. In the present paper, based on the signal statistical detection theory, a method for calculation of the sensitivity and SNR in coherent detection laser warning receiver (LWR) has been proposed. Firstly, the probabilities of the laser signal and receiver noise were analyzed. Secondly, based on the threshold detection theory and Neyman-Pearson criteria, the signal current equation was established by introducing detection probability factor and false alarm rate factor, then, the mathematical expressions of sensitivity and SNR were deduced. Finally, by using method, the sensitivity and SNR of the sinusoidal grating laser warning receiver developed by our group were analyzed, and the theoretic calculation and experimental results indicate that the SNR analysis method is feasible, and can be used in performance analysis of LWR.
2009 Vol. 29 (01): 20-23 [Abstract] ( 523 ) PDF (1267 KB)  ( 728 )
24 Morphology Determination of Multi-Needle Bipolar Corona Discharge by OES
CHEN Hai-feng, SU Peng-hao, ZHU Yi-min*
DOI: 10.3964/j.issn.1000-0593(2009)01-0024-04
Using the method of OES (optical emission spectrum) for measuring N2 emission spectrum, the spacial distribution of energetic electrons in multi-needle bipolar corona discharge at atmospheric pressure was investigated. According to the distribution of N2 second positive band’s intensity ISPB,the outline of ionisation region was drawn accurately. The relationship between ISPB and discharge current I was obtained through the sum of ISPB. There are two ionisation regions in the multi-needle bipolar corona discharge. One is near the HV electrode and the other is near the grounded electrode. The ionisation region exists around the needlepoint within 2-3 mm. The volume of ionisation region becomes big with the applied voltage U increasing. The ionisation region of negative corona is bigger than that of positive corona. Near the HV discharge electrode, the outline of electron avalanche is similar to the configuration of electric field lines in the ionisation region, so the electron avalanche along the axis direction of needle develops farther than that along the radial direction. The electric field in the migration area is weak, and the distribution of space charges is large along the radial direction. The sum of ISPB in each ionisation region is second order linear with I, but the quadratic coefficient is very small. So the sum of ISPB is nearly linear with I, the distribution of ISPB is corresponding to the density distribution of energetic electrons. So the charged particles forming the discharge current in ionisation region are electrons. No emission spectrum of N2 can be measured in migration area, so there is no energetic electron. The energetic electrons only exist in ionisation region and the charged particles in migration area are ions.
2009 Vol. 29 (01): 24-27 [Abstract] ( 1765 ) PDF (1413 KB)  ( 616 )
28 Studies on the Determination of the Flux of Gaseous Pollutant from an Area by Passive Differential Optical Absorption Spectroscopy
LI Ang, XIE Pin-hua, LIU Wen-qing, LIU Jian-guo, DOU Ke
DOI: 10.3964/j.issn.1000-0593(2009)01-0028-05
An optical remote sensing method based on passive differential optical absorption spectroscopy (DOAS) for the determination of the flux of SO2 or other gaseous pollutants from an area (such as industrial area, city) which includes many different atmospheric pollution sources was studied in the present paper. Passive DOAS using the zenith scattered sunlight as the light source provides the column density (the integrated concentration of atmospheric absorbers along the light path) and has been successfully applied to the determination of the flux of gaseous pollutants emitted from the volcano or point source. Passive DOAS instrument installed in a car scanned the plume emitted from an area by circling around the area in this paper. Column density of each selected gaseous pollutant was retrieved from zenith scattered sunlight spectra collected by the instrument by spectral analysis method of passive DOAS in their particular absorption spectral range respectively. Combined with the meteorological (wind field) information during the period of measurement, the net flux value of gaseous pollutant from this area during the measurement could be estimated. DOAS method used to obtain the column density of gaseous pollutant in the section plane of the plume emitted from source and the method of net flux calculation of gaseous pollutant from a certain area are described. Also a passive DOAS instrument was developed and installed in a car to scan the gaseous pollutants from the area surrounded by the 5th Ring Road in Beijing city during a field campaign in the summer of 2005. The SO2 net flux 1.13×104 kg·h-1 and NO2 net flux 9.3×103 kg·h-1 from this area were derived separately after the passive DOAS measured the entire ring road and the wind data were roughly estimated from wind profile radar. The results indicate that this optical remote sensing method based on passive DOAS can be used to rapidly determine the flux of gaseous pollutant (such as SO2,NO2) emitted from an area, especially from a city or an industrial area.
2009 Vol. 29 (01): 28-32 [Abstract] ( 652 ) PDF (2268 KB)  ( 620 )
33 Multi-Wavelength Spectral Aerosol Scale Height in Inshore in Contrast with that in Inland
HAN Yong1,2,RAO Rui-zhong2,WANG Ying-jian2
DOI: 10.3964/j.issn.1000-0593(2009)01-0033-05
In the present paper, based on the exponential attenuation of atmospheric aerosol concentration with height, so using continuous spectrum sun-photometer, forward scatter visibility sensor and hygrothermograph, the authors measured the atmosphere column optical characteristic and plane spectral extinction coefficient on earth on the base of two experiments at some edge of ocean at the same time, respectively, set up the calculative method of multi-wavelength spectral aerosol scale height. Firstly, the authors obtained atmospheric horizontal extinction coefficient with forward scattering visibility sensor, which subtracted molecular extinction coefficient, and could get aerosol extinction coefficient near ground; Then, selecting sea salt model, using OPAC software, the authors also could calculate the aerosol extinction coefficient under different humidity (0%, 50%, 70%, 80%, 90%, 95%, 98% and 99%) and different wavelength (400, 450, 500, 550, 600, 650, 700 and 750 nm), the aerosol extinction coefficient was detected by visibility sensor, using interpolation method, respectively; Finally, using the data of atmospheric columniation optical thickness detected by continuous spectral sun-photometer and subtracted molecular optical thickness corresponding wavelengths were accounted out by Modtran 4.0. The authors obtained the characteristic of spectral aerosol scale height of visible light (wavelength is 400, 440, 532, 550 and 690 nm): with wavelength increments, and spectral aerosol scale height was found to decline neither in inland nor in inshore in China; Spectral aerosol scale height in winter is higher than in summer in southeast inshore; but spectral aerosol scale height in winter is smaller in summer than in inland.
2009 Vol. 29 (01): 33-37 [Abstract] ( 1800 ) PDF (1867 KB)  ( 624 )
38 Algorithm for Estimating Chlorophyll-a Concentration in CaseⅡ Water Body Based on Bio-Optical Model
YANG Wei1,CHEN Jin1*,Mausushita Bunki2
DOI: 10.3964/j.issn.1000-0593(2009)01-0038-05
In the present study, a novel retrieval method for estimating chlorophyll-a concentration in case Ⅱ waters based on bio-optical model was proposed and was tested with the data measured in the laboratory. A series of reflectance spectra, with which the concentration of each sample constituent (for example chlorophyll-a, NPSS etc.) was obtained from accurate experiments, were used to calculate the absorption and backscattering coefficients of the constituents of the case Ⅱ waters. Then non-negative least square method was applied to calculate the concentration of chlorophyll-a and non-phytoplankton suspended sediments (NPSS). Green algae was firstly collected from the Kasumigaura lake in Japan and then cultured in the laboratory. The reflectance spectra of waters with different amounts of phytoplankton and NPSS were measured in the dark room using FieldSpec Pro VNIR (Analytical Spectral Devises Inc., Boulder, CO, USA). In order to validate whether this method can be applied in multispectral data (for example Landsat TM), the spectra measured in the laboratory were resampled with Landsat TM bands 1, 2, 3 and 4. Different combinations of TM bands were compared to derive the most appropriate wavelength for detecting chlorophyll-a in case Ⅱ water for green algae. The results indicated that the combination of TM bands 2, 3 and 4 achieved much better accuracy than other combinations, and the estimated concentration of chlorophyll-a was significantly more accurate than empirical methods. It is expected that this method can be directly applied to the real remotely sensed image because it is based on bio-optical model.
2009 Vol. 29 (01): 38-42 [Abstract] ( 518 ) PDF (2106 KB)  ( 657 )
43 Spectra Analyses of Chitosans Degraded by Hydrogen Peroxide under Optimal Conditions
LIN Fang1,2,JIA Xin-gang1,LEI Wan-xue1,LI Zheng-jun1,ZHANG Ting-you1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0043-05
Chitosans with different average molecular weight (1 500-156 kDa) were prepared under optimal conditions based on our previous research by the depolymerization of initial chitosan using hydrogen peroxide, with maintaining the native structure of natural chitosan as principal consideration. Nitrogen and Carbon components of initial chitosan and degraded products were analyzed by BCHI fully automatic nitrogen determination system and Liquid total organic carbon (TOC) analyzer respectively. Fourier transform infrared (FTIR), 13C nuclear magnetic resonance (13C NMR), X-ray diffraction and circular dichroism (CD) analyses were used to characterize the structure properties of samples. The results indicated that the maximum standard deviations of carbon content and nitrogen content and the degree of deacetylation (DD) of degraded products with the corresponding values of the initial chitosan are 2.4%, 2.3% and 6.9% respectively. Besides, the differentiations of the nitrogen content and DD value of the degraded product with the corresponding values of the initial chitosan are narrowed with the increase in the reaction time. FTIR spectra of resulting products are similar to that of initial chitosan in terms of peak number and position, indicating that there are no other functional groups formed during the degradation. 13C-NMR analyses of initial chitosan and degraded products revealed that the chemical structures of resulting chitosans are not changed to any noticeable extent. X-ray diffraction patterns of initial chitosan and degraded chitosans are alike and show characteristic peaks at 2θ=10.4°and 19.8°under the condition that the initial chitosan was disposed as degraded chitosans. Circular dichroism analyses showed that all the samples exhibit a broad negative band located at about 210 nm assigned to n→π* electronic transition of the —NH—CO— chromophore on a glycosidic ring in acidic media, which demonstrated that degraded chitosans maintain their natural conformation in liquid state substantially. All these confirmed that the degraded chtiosans maintain their natural structure and conformation, and the breakage of β-1,4-glucoside bonds in macromolecule is the basic process under optimal degradation conditions.
2009 Vol. 29 (01): 43-47 [Abstract] ( 1351 ) PDF (1401 KB)  ( 657 )
48 Study on the Preparation and Spectral Characteristics of Bi2S3 Nanoribbons
LU Juan, HAN Qiao-feng, YANG Xu-jie*,LU Lu-de, WANG Xin
DOI: 10.3964/j.issn.1000-0593(2009)01-0048-04
In the present study, bismuth sulfide (Bi2S3) nanoribbons were prepared by the hydrothermal method using bismuth nitrate(Bi (NO3)3·5H2O), thioacetamide (C2H5NS) and nitrilotriacetic acid (C6H9NO6) as raw materials at 180 ℃ for 12 h. The reaction time was largely reduced and the route has been unreported. The constituent, structure and morphology of the products were characterized by XRD, XPS and TEM, respectively. The powder X-ray diffraction (XRD) pattern shows that the Bi2S3 crystals belong to the orthorhombic phase (JCPDS:17-320) with calculated lattice constants a=1.110 6 nm, b=1.099 3 nm and c=0.389 2 nm, which are consistent with the reported values (a=1.114 9 nm, b=1.130 4 nm and c=0.398 1 nm). Transmission electron microscopic (TEM) studies reveal that the appearance of as-prepared Bi2S3 is nanoribbon-like with the typical width of about 100 nm; and the high-resolution transmission electron microscope (HRTEM) image shows that the crystal grows along the y axis. The quantification of X-ray photoelectron spectra (XPS) analysis peaks gives an atomic ratio of 2∶3 for Bi∶S, which is consistent with the given formula of Bi2S3. Furthermore, the Raman and UV-Vis spectra of the product were also studied. Compared with bulk Bi2S3 (236 cm-1), the Raman absorption band of the Bi2S3 nanoribbons (195 cm-1) red-shifts 41 cm-1,which is because of the surface effect of nanomaterials. Furthermore, the product has absorption at the wavelength of about 450 nm in the UV-Vis region. The direct bang gap energy (Eg) was estimated to be about 1.58 eV(Eg of the bulk Bi2S3 is 1.3 eV), which indicates that the product has potential application in the optical and electrical areas.
2009 Vol. 29 (01): 48-51 [Abstract] ( 2123 ) PDF (1596 KB)  ( 515 )
52 Preparation of Surface-Modified Carbon Nanotubes/Silica Composite Gel Glass
HUANG Juan, ZHENG Chan, FENG Miao, ZHAN Hong-bing*
DOI: 10.3964/j.issn.1000-0593(2009)01-0052-04
Owing to their unique structure and properties, carbon nanotubes (CNTs) have become the highlight of research since they were discovered. Part of the research interest lies in introducing them into solid state matrix to make them materialized. However, CNTs tend to aggregate in the matrix, which makes it difficult to make homogeneous composites. In order to solve this problem, we first modified the surface of CNTs by chemically bonding them to 3-aminopropyltrie-thoxysilane (NH2(CH2)3Si(OC2H5)3,APTES) using three-step reactions, and then connected them to silica network by sol-gel technique. In the present paper, CNTs were first treated with HNO3 to get CNTs-COOH, which were then treated with SOCl2 to be transferred to CNTs-COCl, and finally CNTs-COCl reacted with APTES to get CNTs-APTES. After that, CNTs were introduced into silica net work through the individual hydrolysis of CNTs-APTES, tetrathyloxysilane (Si(OC2H5)4,TEOS) and 3-glycidoxy-propltrimethoxysilane (CH2OCHCH2O(CH2)3Si(OCH3)3,GPTMS) as sol-gel precursors, and the copolymerization of their hydrolysis products. FTIR and SEM were used to characterize the composition and microstructure of the obtained samples. Owing to the connection of CNTs with silica network, little aggregation of CNTs was observed and high-quality CNTs/SiO2 composite gel glass was obtained. A model of CNTs/SiO2 network was also given.
2009 Vol. 29 (01): 52-55 [Abstract] ( 1272 ) PDF (1627 KB)  ( 566 )
56 Research on the Polycrystalline CdS Thin Films Prepared by Close-Spaced Sublimation
YANG Ding-yu1,2,XIA Geng-pei1*,ZHENG Jia-gui1,FENG Liang-huan1,CAI Ya-ping1
DOI: 10.3964/j.issn.1000-0593(2009)01-0056-06
In the present paper, the factors of influence on the deposition rate of CdS films prepared by close-spaced sublimation (CSS) were first studied systematically, and it was found from the experiments that the deposition rate increased with the raised temperature of sublimation source, while decreased with the raised substrate temperature and the deposition pressure. The structure, morphology and light transmittance of the prepared samples were tested subsequently, and the results show: (1) The CdS films deposited under different oxygen partial pressure all present predominating growth lattice orientation (103), and further more the films will be strengthened after annealed under CdCl2 atmosphere. (2) The AFM images of CdS show that the films are compact and uniform in grain diameter, and the grain size becomes larger with the increased substrate temperature. Along with it, the film roughness was also augmented. (3) The transmittance in the shortwave region of visible light through the CdS films would be enhanced when its thickness is reduced, and that will help improve the shortwave spectral response of CdTe solar cells. Finally, the prepared CdS films were employed to fabricate CdTe solar cells, which have achieved a conversion efficiency of 10.29%, and thus the feasibility of CSS process in the manufacture of CdTe solar cells was validated primarily.
2009 Vol. 29 (01): 56-61 [Abstract] ( 1325 ) PDF (2726 KB)  ( 753 )
62 Research on Laser Spectrum Detecting Technology Based on Static Mach-Zehnder Interferometer
LI Xiao1,2,ZHANG Ji-long1,2,XUE Shang-feng2,TIAN Er-ming1,2,ZHANG Yue2,WANG Zhi-bin2
DOI: 10.3964/j.issn.1000-0593(2009)01-0062-04
It is the key content of laser warning to reliably and real-time detect the type and characteristic parameters of incident laser. Coherent detection technology detects the information based on the coherence of laser, and is a kind of effective detection technology. In order to detect the incident laser’s spectrum, a kind of device for laser detecting and real time spectrum measurement was designed, which measures the laser spectrum on the bases of coherent detecting technology, Fourier optics and optical signal processing. Using compact and static Mach-Zehnder interferometer as the coherent detection components, it can restrain the background light efficiently. The non-scanning mechanical parts allow fast spectrum detection, and narrow laser pulse can be detected. The real-time signal processing is realized by DSP and multi-channel frame subtraction technology to wipe off the background light, detect the laser and measure its spectrum. The result indicates that, using Mach-Zehnder interferometer and multi-channel frame subtraction technology can realize the laser pulse detection, and improve the measuring precision efficiently; 10 ns laser pulse can be detected and the wavelength measuring error is less than 10 nm.
2009 Vol. 29 (01): 62-65 [Abstract] ( 1379 ) PDF (1329 KB)  ( 701 )
66 Extracting Projections from Laser Moire Interference Spectra
SONG Yi-zhong1,2,ZHAO Zhi-min1,HE An-zhi3
DOI: 10.3964/j.issn.1000-0593(2009)01-0066-04
Laser Moire Interference spectra of rocket exhausted plumes were analyzed. Projections for reconstruction were figured out, and air density distribution was reconstructed. Moire deflectograms of the plumes were produced and captured with a home-made, wide-range, high-sensitivity Moire deflectometer. Moire interference spectra were processed by phase unwrapping technique with Fourier transform, so the space phase distribution of Moire deflectograms was extracted. The background was worked out based on the margin of the Moire deflectograms, and so was the space phase distribution of the background. The phase shift distribution of distorted Moire interference spectra could easily be obtained by calculating the difference between the two space phase distributions. The relative projections could be extracted from the phase shift distribution. The air density distribution of the plumes was calculated by simple self-correlative algebraic reconstruction technique (SSART) based on deflected angles for projections. Eight projections with equal direction interval of 20 degree were used for reconstructing the air density distribution of a plume section. As a result, with phase unwrapping technique based on Fourier transform, any cross section projection could conveniently be worked out from the Moiré deflectogram of rocket exhausted plumes. The air density distribution of the cross section could be reconstructed by SSART. So, SSART with deflected angle for projection is a kind of super nonlinear deflection tomography.
2009 Vol. 29 (01): 66-69 [Abstract] ( 597 ) PDF (1695 KB)  ( 558 )
70 Study of Spectra Characteristics of Ca3SiO5∶Eu2+ Phosphor
LI Pan-lai, WANG Zhi-jun*,YANG Zhi-ping, XIONG Zhi-jun
DOI: 10.3964/j.issn.1000-0593(2009)01-0070-03
The Ca3SiO5∶Eu2+ phosphor was synthesized by the sol-gel reaction method. The emission spectrum was measured by a SPEX1404 spectrophotometer, and the excitation spectrum was measured by a SHIMADZU RF-540 ultraviolet spectrophotometer. All the characterization of the phosphors was conducted at room temperature. The results show that the emission spectrum of Ca3SiO5∶Eu2+ phosphor exhibits one asymmetry band centred at 505 nm under the 365 nm excitation, and the excitation spectrum for 505 nm indicates two bands centred at 374 and 397 nm, respectively. The above results indicate that the phosphor used for w-LEDs can be excited by UV light, and emit green light. The effect of synthesis condition, such as synthesis temperature, synthesis time and Eu2+ concentration, on the emission spectrum of Ca3SiO5∶Eu2+ phosphor was investigated. The results show that the emission peak intensity of Ca3SiO5∶Eu2+ phosphor firstly increases, then decreases with the increase in synthesis temperature or synthesis time or Eu2+ concentration, and reaches the maximum value at 1 100 ℃, for 4 h and 0.5 mol% Eu2+.
2009 Vol. 29 (01): 70-72 [Abstract] ( 1048 ) PDF (1511 KB)  ( 488 )
73 Determination of Pazufloxacin Mesylas by Terbium Sensitized Chemiluminescence Method
LI Jian-jun1,ZHANG Zu-ling1,QU Ling-bo1, 2,YANG Ran2
DOI: 10.3964/j.issn.1000-0593(2009)01-0073-05
Tb3+ can form chelate with pazufloxacin mesylas (PM), and the complex of terbium-pazufloxacin mesylas(Tb3+-PM) can sensitize the chemiluminescence (CL) intensity of KMnO4-Na2SO3 system through energy transfer. Based on the chemiluminescence reaction, a new sensitized chemiluminescence method was developed for the determination of PM by flow-injection. Under the optimum conditions, the enhanced CL intensity was linear with the concentration of PM in the range of 0.10-12 mg·L-1 with the detection limit of 0.04 mg·L-1. The relative standard deviation for eleven continuous determinations of 1.0 mg·L-1 PM was 1.9%. This method has been applied to the determination of PM in injection and body fluid with satisfactory results. This method has the merits of simpleness, speediness,sensitivity and good reproducibility. An original mechanism was proposed to explain this phenomenon.
2009 Vol. 29 (01): 73-77 [Abstract] ( 276 ) PDF (1334 KB)  ( 555 )
78 Spectroscopy Study of Binding Mechanisms and Molecular Recognition of Methamidophos-Specific Moleculary Imprinted Polymer
SHEN Zhong-lan, YANG Jun, ZHU Xiao-lan, GAO Yun, SU Qing-de*
DOI: 10.3964/j.issn.1000-0593(2009)01-0078-04
A new methamidophos-specific molecularly imprinted polymer (MIP) was synthesized based on non-covalent interaction. The complexes formed between MAP and MAA were evaluated by 1H NMR, FTIR and UV spectrometry. The MAP-MAA complexes of 1∶2 mole ratio were obtained by cooperative hydrogen bonding and the complexes possessed better stabilization (K=2.894×106 L2·mol-2). The Infrared spectrometry differences of the MIPs before and after saturated with MAP further indicated that there were carboxyl functional groups in the MIP, which could interact with the template by cooperative hydrogen bonding specifically.
2009 Vol. 29 (01): 78-81 [Abstract] ( 2308 ) PDF (1548 KB)  ( 652 )
82 FTIR Assessment of the Secondary Structure of Proteins in Royal Jelly under Different Storage Conditions
WU Li-ming1,2,ZHOU Qun3,ZHOU Xiao2,ZHAO Jing2,SUN Su-qin3*,HU Fu-liang1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0082-06
The quality of royal jelly has a high positive correlation with its storage periods and temperature. In the present paper, Fourier transform infrared spectra (FTIR) of royal jelly was measured with different temperatures and storage periods, and the compositions of the secondary structure of protein were determined by curve-fitting analysis of the amide Ⅰ bands in the FTIR spectra. The results showed that the spectral differences were observed among these types of samples, the composition of the secondary structures of protein exhibited extreme difference, and the rate of α-helix decreased and β-sheet increased dramatically with the increase in storage temperature and periods. The content of β-turn also tended to increase, and the order of their change extent was 28 ℃>16 ℃>4 ℃>-18 ℃. These results met the theory that royal jelly should be kept under lower temperature. So, FTIR spectroscopy combined with several data-processing methods, such as secondary derivative, deconvolution, and curve fitting would be an effective method for assessing the quality and freshness of royal jelly.
2009 Vol. 29 (01): 82-87 [Abstract] ( 2368 ) PDF (2337 KB)  ( 780 )
88 Characterization of Structure of Carboxymethylpachymaran by IR Spectrum and Atomic Force Microscopy
WANG Bo1,SUN Run-guang1*,ZHANG Jing2
DOI: 10.3964/j.issn.1000-0593(2009)01-0088-05
The structure of Carboxymethylpachymaran was characterized using Fourier transform infrared spectroscopy. Morphological changes of carboxymethylpachymaran (CMP) were observed under different solution conditions by atomic force microscopy(AFM). After the carboxymethylation, the solubility of pachyman in the water was significantly increased, its β-D-glucan characteristic absorption peak at 890 cm-1 became weak obviously, and its methylene vibration absorption peak and CO antisymmetrical stretch vibration absorption peak appeared at 1 333 and 1 606 cm-1 respectively, which indicated that the carboxymethylation succeeded. The analysis of AFM results showed that CMP molecules existed in different morphology under different solution conditions, and that the concentration, ionic strength and solvent physical chemistry characteristics of polysaccharide solution had effects on the CMP chains conformation and the action mode between different molecular chains. The phenomena were considered to be related to hydrogen bond association and intramolecular and intermolecular electrostatic interactions of CMP. Meanwhile, the affinity and electrostatic interaction between CMP molecules and the mica substrate also had an influence on the CMP chains conformation and the image quality.
2009 Vol. 29 (01): 88-92 [Abstract] ( 2570 ) PDF (1573 KB)  ( 525 )
93 Study on Traditional Chinese Medicine Extracts of Rhizoma Coptidis by FTIR Spectroscopy
WU Yan-wen1,XIAO Xiao-he2,SUN Su-qin3,LIU Hong-xia3
DOI: 10.3964/j.issn.1000-0593(2009)01-0093-04
In the present paper, we applied Fourier transform infrared spectroscopy (FTIR) and second derivative infrared spectroscopy to establish a rapid and efficient analytical method for a preliminary quality control of medicinal herb extracts. The commonly used Chinese herb medicine, Rhizoma coptidis, was taken as an example. The main component-berberine in rhizoma coptidis was analyzed as target compound. The results indicated that the IR spectra of rhizoma coptidis herb, its water and alcohol extracts, exhibit their macroscopic fingerprint characters with fine repeatability, and the corresponding secondary derivative spectra further confirmed the spectral characteristics of the original IR spectra by enhancing spectral resolution. The typical and strongest absorption band of IR spectrum of berberine is at 1 505 cm-1,which is assigned to aromatic skeleton vibration band, and its intensities in spectra of rhizoma coptidis herb and its different extracts become the main identification standard of the contents of berberine in those samples. In addition, comparing the IR spectra of the medicinal herb and its extracts, it was shown that the main bioactive components, alkaloids in rhizoma coptidis herb, are enriched by extraction, and the contents of berberine in alcohol extracts of rhizoma coptidis are higher than those in water extracts. The spectroscopic technique described is a simple and rapid analytical technique, which could provide valuable information about chemical constituents of medicinal extracts for guiding further chromatographic analysis and separation improvement.
2009 Vol. 29 (01): 93-96 [Abstract] ( 2510 ) PDF (1312 KB)  ( 776 )
97 Infrared Spectroscopic Study on the Component and Vigor Analysis of Cistanche Deserticola Seeds
XU Rong1,SUN Su-qin2,CHEN Jun1*,CHEN Shi-lin1,ZHOU Feng1
DOI: 10.3964/j.issn.1000-0593(2009)01-0097-05
Comparative study of the different parts of cistanche deserticola seeds and their changes after different processing were examined by Fourier transform infrared spectroscopy spectra (FTIR). The results of the analysis showed that components in the cistanche deserticola seeds were abundant, which contained characteristic absorption peaks of protein, fat and carbohydrate. As well, pectin and aromatic compound can be also found in the seeds. However, the components were different in different parts of cistanche deserticola seeds. The characteristic absorption peak intensities of fat at 2 926, 1 746, 1 161 and 721 cm-1 were the strongest in the seed kernels. However, the seed coats mainly consisted of carbohydrate and pectin, which were showed at 1 054 cm-1. The contents of protein and carbohydrate were decreased distinctly in the moldy and dead seeds after processing. The characteristic absorption peak intensity ratio of protein to fat (I1 630I1 745) was all higher than 1.05 in the live seeds. The characteristic absorption peak intensity ratio of amido link I of protein to fat (I1 653I1 745) in the dead seed kernels of the cistanche deserticola was decreased from 0.31 to 0.23, which was 25.8% less than that in vital seed kernels. The results suggest that FTIR not only can be used in fast comprehensive analysis of seed components, but also can be used in the seed vigor analysis, seed longevity determination and seed quality evaluation.
2009 Vol. 29 (01): 97-101 [Abstract] ( 672 ) PDF (1693 KB)  ( 876 )
102 Visible/NIR Analysis of Fat, Protein and Water in Chilled Pork
LIU Kui-wu, CHENG Fang*,LIN Hong-jian, SUN Tong, XU Kai, HU Lei-xiu, YING Yi-bin, XU Hui-rong
DOI: 10.3964/j.issn.1000-0593(2009)01-0102-04
Fat, protein and water were determined by visible and NIR transmittance spectroscopy in chilled pork. After preprocessed by multiplicative scatter correction (MSC), the quantitative analysis models were developed based on the original, first derivative and second derivative spectra by using partial least squares (PLS) at the temperatures of 0-4 ℃ and 20 ℃, respectively. By comparing the correlation coefficient (r), RMSEC, and SEP, we found that the first derivative model was the best, and the performance for 0-4 ℃ was better than that for 20 ℃. At 0-4 ℃ and 20 ℃, the correlation coefficients were 0.950 and 0.924 for fat, 0.713 and 0.455 for protein and 0.944 and 0.914 for water respectively, SEP values were 2.41 and 2.95 for fat, 5.44 and 4.25 for protein, and 2.37 and 2.38 for water respectively. The results showed that the visible and NIR analysis could measure the fat and water contents in chilled pork well, but was bad for protein, and this was caused by processing line of chilled pork. What’s more, the spectrum offset was found in the original spectra at about 770 nm to be about 10 nm.
2009 Vol. 29 (01): 102-105 [Abstract] ( 227 ) PDF (1270 KB)  ( 847 )
106 Measuring Fatty Acid Concentration in Maize Grain by Near-Infrared Reflectance Spectroscopy
YANG Xiao-hong, GUO Yu-qiu, FU Yang, HU Jie-yun, CHAI Yu-chao, ZHANG Yi-rong, LI Jian-sheng*
DOI: 10.3964/j.issn.1000-0593(2009)01-0106-04
The fatty acid concentrations in maize grain were analyzed with a set of 294 samples including normal inbred lines, high-oil inbred lines and high-oil recombinant inbred lines (RIL). The method of partial least squares (PLS) regression with internal cross validation was employed to develop the measuring models of near-infrared reflectance spectroscopy (NIRS) for concentrations of four major fatty acids, palmitic, stearic, oleic and linoleic acids, as well as oil concentration in maize grain. The NIRS models were accurate for oleic acid, linoleic acid and oil concentrations. The determination coefficients of these models in cross validation were 0.89, 0.88 and 0.91, respectively; the determination coefficients in external validation were 0.86, 0.84 and 0.92, respectively; and the ratio of standard deviation (SD) to root mean square error of validation (RMSEV) in both calibration and external validation sets (RSC(P)) was higher than 2.5. But the models for palmitic and stearic acid concentrations were not accurate enough with determination coefficients in cross validation and external validation lower than 0.80, and RSC(P) lower than 2.5. Further practical validation showed that the predicted results by using NIRS models for oleic acid, linoleic acid and oil concentrations were accurate and reliable, which will be a useful approach to the measurement of a large number of breeding samples during genetic improvement of oil quality and quantity in maize.
2009 Vol. 29 (01): 106-109 [Abstract] ( 265 ) PDF (960 KB)  ( 613 )
110 FTIR and Classification Study on the Powdered Milk with Different Assist Material
ZHOU Jing1,2,SUN Su-qin2,LI Yong-jun1,ZHOU Qun2
DOI: 10.3964/j.issn.1000-0593(2009)01-0110-04
The near infrared spectrum atlases of milk powders mingled with different adjuvant are the object for cluster analysis. Drawing assistance from the disparity in infrared fingerprint atlas that change according to the contents of chemical constituent, and making mingled component models, the milk powders mingled with different adjuvant were taken for a rapid sorting test using SIMCA clustering analytical method. In the experiment, two hundred fifty sorts of milk powders in the markets from different manufacturers were scanned by near infrared ray, and were tested with reproducibility determination. It was found difficult to extract fingerprint characters just from the external appearance of the near infrared spectrum atlases from milk powders mingled with different adjuvant, and it is needed to adopt pattern recognition technique to determine intelligently. One hundred sixty atlases were drawn out randomly for cluster analysis, and unknown samples were pretested. Results showed that the milk powders mingled with different adjuvant can be identified by near infrared spectrum analysis associated with cluster analysis methods, notwithstanding the similar near infrared spectrum atlases of different sample were difficult to identify directly. No overlapping phenomenon was found among milk powders mingled with different adjuvant, and they did not interfere with each other. The results from clustering spectra between samples were satisfactory, and the correct ratios of blind detections were over 90﹪. In addition, the correct ratios of this method may be elevated remarkably with sufficient number of samples, increasing training set sample quantity and sampling representation, and strengthening the standard degree of manipulation. It is concluded that the designed model to determine milk powders mingled with different adjuvant is rational, and the determination capability is fine.
2009 Vol. 29 (01): 110-113 [Abstract] ( 2197 ) PDF (1247 KB)  ( 593 )
114 Analysis of Visible and Near-Infrared Spectra of As-Contaminated Soil in Croplands Beside Mines
REN Hong-yan1, 2, 3,ZHUANG Da-fang1, 2*,QIU Dong-sheng2, 3,PAN Jian-jun1
DOI: 10.3964/j.issn.1000-0593(2009)01-0114-05
Soil samples in the depth from 0 to 20 cm were scooped from agricultural region beside mines and prepared for determination of As concentration, Fe concentrations and organic matter content. At the same time they were scanned by mobile hyperspectral radiometer for visible and near-infrared spectra. Savitzky-Golay filter was used to smooth noises in spectrum curve because of some low signal-to-noise ratios in some regions of visible and near-infrared light, and all the spectra were resampled with the spectral interval of 10 nm. Before principal component regression and partial least square regression models were constructed for predicting As concentration, Fe concentrations and OM content, several spectral preprocessing techniques like first/second derivative (F/SD), baseline correction (B), standard normalized variate (SNV), multiplicative scatter correction (MSC) and continuum removal (CR) were used for promotion of models’ robustness and predicting performance. For limited samples, cross validation was carried out by repeated leave-one-out procedure, and root mean square error of prediction (RMSEP) was used for validating the prediction ability of constructed models. In this study principal component regression models behave better than partial least square regression models in representing regressing ability, reducing risk of over-fitting with less factors and ensuring models’ accuracy and pertinences (relative RMSEP and R2). Preprocessing techniques of SNV, MSC and CR improve obviously the prediction ability of models for As concentration, Fe concentrations and OM content with relative RMSEP equal to 0.304 0, 0.144 3 and 0.171 2, with number of factors equal to 5, 3 and 3, respectively. The analysis of regression vectors of selected optimal PCR models shows that several important wavelengths are simultaneously taken and helpful for prediction performance: 450, 1 000, 1 400, 1 900, 2 050, 2 200, 2 250, 2 400 and 2 470 nm. Application of the calibrated models to soil contamination of croplands is promising. Concentrations of soil contaminants and contents of other matter can be determined by reflectance spectroscopy with high spectra resolution, which would provide potent reference for remote sensing monitoring of soil and environmental quality.
2009 Vol. 29 (01): 114-118 [Abstract] ( 2368 ) PDF (1549 KB)  ( 591 )
119 Characterization of Kale(Brassica Oberacea var Acephala) under Thallium Stress by In Situ Attenuated Total Reflection FTIR
YAO Yan1,ZHANG Ping2,WANG Zhen-chun1,CHEN Yong-heng2
DOI: 10.3964/j.issn.1000-0593(2009)01-0119-03
The experiment was designed based on consumption of carbon dioxide through the photosynthesis of Brassica oberacea var acephala leaf, and the photosynthesis of kale leaf under thallium stress was investigated by in situ attenuated total reflection FTIR (in situ ATR-FTIR). The ATR-FTIR showed that the absorption peaks of leaves had no obvious difference between plants growing in thallium stress soil and plants growing in non-thallium pollution soil, and the strong peaks at 3 380 cm-1 could be assigned to the absorption of water, carbohydrate, protein or amide; the strong peaks at 2 916 and 2 850 cm-1 assigned to the absorption of carbohydrate or aliphatic compound; the peaks at 1 640 cm-1 assigned to the absorption of water. However, as detected by the in situ ATR-FTIR, the double peaks (negative peaks) at 2 360 and 2 340 cm-1 that are assigned to the absorption of CO2 appeared and became high gradually. It was showed that kale was carrying photosynthesis. At the same time, the carbon dioxide consumption speed of leaf under thallium stress was obviously larger than that of the blank. It was expressed that photosynthesis under thallium stress was stronger than the blank. All these represented that kale had certain tolerance to the heavy metal thallium. Meanwhile, the carbon dioxide consumption of grown-up leaf was more than that of young leaf whether or not under thallium stress. It was also indicated that the intensity of photosynthesis in grown-up leaf is higher than that in young leaf.
2009 Vol. 29 (01): 119-121 [Abstract] ( 1903 ) PDF (1517 KB)  ( 529 )
122 Progress in Application of Near Infrared Spectroscopy to Nondestructive On-line Detection of Products/Food Quality
SUN Tong, XU Hui-rong*,YING Yi-bin
DOI: 10.3964/j.issn.1000-0593(2009)01-0122-05
Increasing safety events caused by products/food quality problems has caught more and more attention, therefore nondestructive fast detection of products/food quality becomes necessary. At present, fast detection methods commonly used include chemical colorimetric method, near infrared spectroscopy (NIRS) technique, immunoassay method, bio-sensor technique, biomicroarray method, bioluminescence method, and so on. NIRS technique has found wide application in products/food quality detection because of its characteristics such as very high speed, no sample preparation, non-destruction, no pollution, low cost etc. Many research works have been done on products/food quality detection using NIRS technique both home and abroad, from static laboratory investigations to online investigations. In the present paper, basic knowledge of NIRS and its analysis process were briefly introduced. The applications of NIRS technique in online quality detection and control of fruit, fish, meat, milk, grain, fermentation of cheese and alcohol etc were reviewed. Finally, the existing problems of NIRS were pointed out and the prospect of NIRS technique was discussed. In the future, NIRS technique will combine with network technique to realize online update and upgrade of NIR models. And spectral imaging technique will be the development trend of NIRS technique in the 21st century.
2009 Vol. 29 (01): 122-126 [Abstract] ( 2389 ) PDF (1471 KB)  ( 1149 )
127 Multiple Dependent Variables LS-SVM Regression Algorithm and Its Application in NIR Spectral Quantitative Analysis
AN Xin1,3,XU Shuo2,ZHANG Lu-da1*,SU Shi-guang1
DOI: 10.3964/j.issn.1000-0593(2009)01-0127-04
In the present paper, on the basis of LS-SVM algorithm, we built a multiple dependent variables LS-SVM (MLS-SVM) regression model whose weights can be optimized, and gave the corresponding algorithm. Furthermore, we theoretically explained the relationship between MLS-SVM and LS-SVM. Sixty four broomcorn samples were taken as experimental material, and the sample ratio of modeling set to predicting set was 51∶13. We first selected randomly and uniformly five weight groups in the interval [0, 1], and then in the way of leave-one-out (LOO) rule determined one appropriate weight group and parameters including penalizing parameters and kernel parameters in the model according to the criterion of the minimum of average relative error. Then a multiple dependent variables quantitative analysis model was built with NIR spectrum and simultaneously analyzed three chemical constituents containing protein, lysine and starch. Finally, the average relative errors between actual values and predicted ones by the model of three components for the predicting set were 1.65%, 6.47% and 1.37%, respectively, and the correlation coefficients were 0.994 0, 0.839 2 and 0.882 5, respectively. For comparison, LS-SVM was also utilized, for which the average relative errors were 1.68%, 6.25% and 1.47%, respectively, and the correlation coefficients were 0.994 1, 0.831 0 and 0.880 0, respectively. It is obvious that MLS-SVM algorithm is comparable to LS-SVM algorithm in modeling analysis performance, and both of them can give satisfying results. The result shows that the model with MLS-SVM algorithm is capable of doing multi-components NIR quantitative analysis synchronously. Thus MLS-SVM algorithm offers a new multiple dependent variables quantitative analysis approach for chemometrics. In addition, the weights have certain effect on the prediction performance of the model with MLS-SVM, which is consistent with our intuition and is validated in this study. Therefore, it is necessary to optimize weights in multiple dependent variables NIR modeling analysis.
2009 Vol. 29 (01): 127-130 [Abstract] ( 2466 ) PDF (981 KB)  ( 902 )
131 XRD and FTIR Spectra Characteristics of Nacreous Layer in Perna Viridis
JIA Tai-xuan1,2,LIU Zi-li1,2*,ZHANG Gang-sheng1
DOI: 10.3964/j.issn.1000-0593(2009)01-0131-03
The XRD and FTIR of aragonites in nacreous and prismatic layer of perna viridis were systematically measured, and the frequency variations of ν1,ν2 and ν4 band of aragonites were especially analyzed. The results showed that both of them were aragonite and the frequency of ν2 band differed in them, but the frequencies of other two bands were not altered and had the same values with cavernous aragonite. In the same specie of shell, the frequency of ν2 band in nacreous layers was greater than that in prismatic layers, and there was a frequency shift of ν2 band between them. For the first time, the phase transformation of biogenic aragonite was detected. After nacreous aragonite was heated at 300 ℃, the frequency shift of ν2 band was found. So it is concluded that the biogenic aragonite is related to the thermal effects in crystallizing process, meanwhile it stores excess energy. All of these can provide experiential basis for studying biomineralization theory.
2009 Vol. 29 (01): 131-133 [Abstract] ( 2232 ) PDF (1389 KB)  ( 698 )
134 FTIR and XRD Analysis of the Enzymatic Degradation of Crosslinked Starch Microspheres
LI Zhong-jin,YU Li-li*,ZHU Lei
DOI: 10.3964/j.issn.1000-0593(2009)01-0134-04
Crosslinked starch microspheres (CSM) were prepared by crosslinking of soluble starch and N,N’-methylene-bis-acrylamide in inverse suspension. In order to describe the enzymatic degradation of CSM in this experiment, soluble starch, CSM and CSM’s degradation product obtained from the simulated intestinal fluid in different time were analysed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD). The FTIR and SEM results showed that the CSM’s crosslinking structure could be maintained steady in digested liquid within 3 hours. The intensity at 1 090 cm-1 related to bending vibration bands of C—O—C, the amide band Ⅰ and the amide band Ⅱ became weaker in 3-12 hours along with the process of the enzymatic degradation, indicating the degradation of the molecular chain of starch and the depolymerization of the cross-linking structure. And then the disappearing of the amide band Ⅰ and the amide band Ⅱ indicated that the crosslinking structure was totally destructed after 12 hours and thereafter the enzymatic degradation was consistent with soluble starch. The XRD results proved that after 12 hours the CSM’s degradation was similar to starch’s degradation, their non-crystalline parts were decomposed, and their degree of crystallinity increased with the development of the degradation, but did not exceed the crystallinity of soluble starch.
2009 Vol. 29 (01): 134-137 [Abstract] ( 1322 ) PDF (1537 KB)  ( 612 )
138 LO Phonon-Plasmon Coupled Mode in Hexagonal InGaN Alloy
WANG Rui-min, CHEN Guang-de
DOI: 10.3964/j.issn.1000-0593(2009)01-0138-04
Raman scattering spectra of hexagonal InGaN/GaN film, excited with 532 and 488 nm visible laser lines and 325 nm UV laser line, were investigated at room temperature and 78 K. The sample was grown by metalorganic chemical vapor deposition on a sapphire substrate. Excited with 532 and 488 nm visible laser lines, the E2 and A1(LO) modes were observed at about 571.3 and 736.4 cm-1,respectively. These scattering signals mainly originate from GaN layer. Excited with 325 nm UV laser line, the E2 mode shifts to 569.7 cm-1,while A1(LO) mode shifts to 730.3 cm-1 and resonance is enhanced. These scattering signals originate from InGaN layer. A broad feature at high frequency of A1(LO) mode was observed in spectroscopy excited with visible laser line, and was attributed to the LO phonon-plasmon coupled mode of InGaN layer. The electron concentration of InGaN film determined from the frequency of the coupled mode is n=1.61×1018 cm-3. Excited with 325 nm UV laser light, the LO phonon-plasmon coupled mode is absent, and the scattering signal of A1(LO) mode mainly originates from the surface depletion layer of the sample. The thickness of the surface depletion layer is about 40 nm. Furthermore, the scattering intensities of LO phonon-plasmon coupled mode at room temperature and 78 K were compared and analyzed. The screening wave vectors of plasmon at different temperatures were calculated. At low temperature, the screening wave vector increases, the damping of the plasmon decreases, so the LO phonon-plasmon coupled mode becomes stronger. This work is helpful in understanding the property of InGaN and in developing the optoelectronic devices of nitride.
2009 Vol. 29 (01): 138-141 [Abstract] ( 1862 ) PDF (1349 KB)  ( 661 )
142 A Study of Raman Spectra Denoising Based on Empirical Mode Decomposition
LI Qing,ZHANG Guo-ping,LIU Yang
DOI: 10.3964/j.issn.1000-0593(2009)01-0142-04
The multiresolution empirical mode decomposition (EMD) is a new method of analyzing signal. It can be interpreted as a temporal and spatial filtering based on the extremum characteristic scale of the signal. This method can preserve the nonlinearity and non-stability of signal, and has potential superiority in filtering and denoising. In the present paper, a new denoising method of Raman spectra on the basis of empirical mode decomposition with multiresolution filtering is presented. First, Raman spectra polluted by the white noise is decomposed into several intrinsic mode function (IMF) components of different time scale based on empirical mode decomposition (EMD). Then, the IMF components of high frequencies are preprocessed using the threshold method, and we add these IMF components to the IMF components of low frequencies to achieve denoising signal. For various noise levels, the effects of three methods (the EMD threshold denoising, the wavelet threshold denoising and the EMD low-pass filtering) are analyzed by processing the noisy p-xylene spectra. The results show that the EMD threshold denosing method eliminates the noise effectively. In addition, this method also preserves the detailed information of the original spectra well. By contrast with the wavelet threshold denosing method, the EMD threshold denoising requires no prior knowledge about the sample composition and no selection of the suitable decomposition level, and the adaptation is in evidence. The new method will have a good application prospect in Raman spectra denoising.
2009 Vol. 29 (01): 142-145 [Abstract] ( 557 ) PDF (1378 KB)  ( 716 )
146 Characteristic Vibration Analysis of M-RNA Nucleic Acid Bases Complexes(M=Ca+ and Mg+) by DFT
ZHANG Xing-chu1, 2,HU Yi-hua2*,WANG Xiao-juan3
DOI: 10.3964/j.issn.1000-0593(2009)01-0146-05
A density functional investigation of the interaction between calcium and magnesium univalent cations and RNA pyrimidine base (cytosine, thymine and uracil) was performed to determine geometric coordinates and free energies for all possible stable isomers at B3LYP/6-311+G(2df, 2p) level. The most stable isomers C1M, T1M and U1M (M=Ca+ and Mg+) with the lowest free energy among the same pyrimidine base tautomers were calculated to determine the characters of infrared vibrations. According to the results, two characteristic infrared vibrations at wave numbers 1 684 and 1 765 cm-1 were found for single pyrimidine base C1,at 1 747 and 1 792 cm-1 for T1,1 763 and at 1 796 cm-1 for U1. In addition, spectrum shifts were found when the cations interact with the pyrimidine base tautomers. For deeper analysis, we found that when the stable complexes are formed, the cations are prone to act on the oxygen atoms, and cause the vibrational frequencies to change, the spectral lines belonging to the vibration of C—O—M turn out to redshift and the others turn out to blueshift. When the stable complex C1M is formed, the characteristic infrared vibration at 1 684 cm-1 mainly caused by the ring’s vibration turns out to blueshift about 10 cm-1,and the another characteristic vibration of 1 765 cm-1 caused by vibration of bond C—O with oxygen atom acting on cations directly turns out to redshift by 112 cm-1 for complex C1Ca+ and by 110 cm-1 for C1Mg+. When the stable complexes T1M are formed, the characteristic vibration of bond C—O—M turns out to redshift about 130 cm-1 and the vibration of bond C—O turns out to blueshift about 55 cm-1. When the stable complexes U1M are formed, the vibration of bond C—O—M truns out to redshift about 90 cm-1 and about 50 cm-1 for another C—O. The characteristic infrared vibration frequencies are changed obviously when tautomers act on the cations, which is mainly because cations take part in molecule’s vibrations and change the force constants and reduced masses.
2009 Vol. 29 (01): 146-150 [Abstract] ( 294 ) PDF (1548 KB)  ( 519 )
151 Study on Concentration Quenching and Energy Transfer in Ln3+ (Ln=Tb, Tm, Eu) in Y2O3 Nanocrystal Powders
MENG Qing-yu1,2,CHEN Bao-jiu3*,XU Wu4,ZHAO Xiao-xia2,YANG Yan-min2,DI Wei-hua2,WANG Xiao-jun2
DOI: 10.3964/j.issn.1000-0593(2009)01-0151-05
Nano-powders Y2O3 with various particle sizes and different doping concentrations of Ln(Ln=Tb, Tm, Eu) were prepared by using a combustion technique. The bulky powders doped with concentrations corresponding to nano-powders were obtained by annealing the nano-powders at high temperature. The emission spectra, XRD spectra and TEM were used in the present study. The concentration quenching of luminescent centers and energy transfer between luminescent centers in Y2O3∶Ln nanocrystal powders were investigated. It was found that the behaviors of luminescence concentration quenching for 5D47F5∶Tb3+ and 5D07F2∶Eu3+ in nano-powders are similar to that in bulky powders. On the contrary, the quenching concentrations for 5D37F5∶Tb3+ and 1D23H4∶Tm3+ are distinctly higher than that in bulk powders. This owes to the size confinement effect: the interface of nanocrystal particles can stop a portion of the energy transfer, which happens in the bulk ones, between luminescent centers. The size confinement effect can bring different influences to the different types of energy transfer. For instance, it will restrain the energy transfer (governed by electric dipole-dipole interaction) between the ions in long distances, and will hardly affect the energy transfer (governed by exchange interaction) between the ions locating at near intervals.
2009 Vol. 29 (01): 151-155 [Abstract] ( 536 ) PDF (1871 KB)  ( 644 )
156 Study on Synthesis, Structure Characterization and Fluorescence of Europium Complexes of 2-(4-Fluorobenzoyl) Benzoic Acid
WANG Juan1,GENG Xiao-tian1,LI Zhao-ye1,ZHAO Ying2,WU Hong3,YAN Jian-bo3,WANG Yun-you3,SUN Bo1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0156-05
The present paper reports three new europium complexes, EuL3(H2O)6,EuL3Phen(H2O)4 and EuL3(TPPO)(H2O)5,synthesized with Eu(NO3)3·6H2O, 2-(4-fluorobenzoyl) benzoic acid, Phen and TPPO(L=2-(4-fluorobenzoyl) benzoic acid, Phen=1,10-phenanthroline, TPPO=triphenyl phosphine oxide). Their composition and chemical structures were characterized by elemental analysis, IR and 1H NMR spectroscopy. The IR spectra indicated that all complexes exhibited the characteristic peaks of carboxylate, asymmetric stretching vibration (νas(CO-2)) and symmetric stretching vibration (νs(CO-2)) peaks; the CO stretching band at 1 692 cm-1 of COOH and the O—H stretching band around 2 500-3 200 cm-1 disappeared. All these complexes had a smaller Δνas(CO-2)-νs(CO-2)) value than that of NaL, so the carboxylate groups coordinated with the europium ion in the form of bridging bidentate. In 1HNMR, the signals of hydrogen in 2-(4-fluorobenzoyl) benzoic acid became wide and shifted upfield, and those in Phen, TPPO shifted downfield. The excitation and emission spectra were recorded at room temperature. The excitation spectra showed that the optimum excitation peaks of these three complexes, EuL3(H2O)6,EuL3Phen(H2O)5 and EuL3(TPPO)(H2O)5,were at 353.0, 355.0 and 357.0 nm, respectively. All these three complexes showed Eu3+ ion characteristic emission bands, the electron-dipole transition 5D07F2 and magnetism dipole transition 5D07F1; their emission peaks were at 596.0,617.0;596.0,619.0;595.0,620.0 nm, and the relative intensities were 1.1,8.6;15.2,100.0;3.6,23.2, respectively. The intensity of 5D07F2 was stronger than that of 5D07F1,which indicated that europium ions were at asymmetric center. The emission intensities of europium ions were greatly sensitized by Phen.
2009 Vol. 29 (01): 156-160 [Abstract] ( 596 ) PDF (1164 KB)  ( 554 )
161 Fluorescence Peak Shift Corresponding to High Chlorophyll Concentrations in Inland Water
DUAN Hong-tao1,2,MA Rong-hua1,ZHANG Yuan-zhi3,ZHANG Bai2
DOI: 10.3964/j.issn.1000-0593(2009)01-0161-04
Hyperspectral remote sensing offers the potential to detect water quality variables such as Chl-a by using narrow spectral channels of less than 10 nm, which could otherwise be masked by broadband satellites such as Landsat TM. Fluorescence peak of the red region is very important for the remote sensing of inland and coastal waters, which is unique to phytoplankton Chl-a that takes place in this region. Based on in situ water sampling and field spectral measurement from 2004 to 2006 in Nanhu Lake, the features of the spectral reflectance were analyzed in detail with peak position shift. The results showed: An exponential fitting model, peak position=a(Chl-a)b,was developed between chlorophyll-a concentration and fluorescence peak shift, where a varies between 686.11 and 686.29, while b between 0.006 2 and 0.006 5. It was found that the better the spectral resolution, the higher the precision of the model. Except that, the average of peak shift showed a high correlation with the average of different Chl-a grades, and the determination coefficient (R2) was higher than 0.81. It contributed significantly to the increase in the accuracy of the derivation of chlorophyll values from remote sensing data in Nanhu Lake. There is satisfactory correspondence between hyperspectral models and chl-a concentration, therefore, it is possible to monitor the water quality of Nanhu lake throngh the hyperspetral remote sensing data.
2009 Vol. 29 (01): 161-164 [Abstract] ( 149 ) PDF (1401 KB)  ( 633 )
165 Research on DNA Fluorescence Capillary Biosensor Marked by Goldview
WANG Yan-jun1,LI Yong-sheng2*,YANG Quan-yu1,HUANG Yi1,TANG Jing1,GAO Xiu-feng1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0165-04
Goldview marked DNA fluorescence capillary biosensor was studied in the present paper. Based on fluorescence capillary analysis (FCA), the DNA biosensor uses capillary as immobilization carrier and detection carrier of DNA probe. Probes (20-mer-ssDNA) were immobilized on the inner wall of capillary by poly-l-lysine, and DNA fluorescence capillary biosensor (DNA-FCB) was made. After being hybridized with complementary target DNA and dyed by Goldview, the target DNA was qualified or quantified by detecting the fluorescence density of the Goldview using F-4500 spectrofluorometer. The sample volume was 12 μL.The concentration of the target DNA showed good linearity with the fluorescence intensity in the range of 0.4-4 μmol·L-1 (2.4-24 mg·L-1)(y=65.911x+3.994 4,r=0.998 9). The RSD was lower than 3.5%. The concentration detection limit of the target DNA was 0.39 μmol·L-1(2.2 mg·L-1). The DNA-FCB can be used to qualify or quantify the target DNA. It’s advantages are simplicity of manipulation, thimbleful of sample and reagent volumes, repeated use of capillary, and the lowest test cost. By using DNA-FCB to qualify the target DNA, we can consumedly decrease the pollution of the environment.
2009 Vol. 29 (01): 165-168 [Abstract] ( 2232 ) PDF (1403 KB)  ( 553 )
169 Quantum Chemistry Study on Fluorescence Spectra of Three Aromatic Hydrocarbons
ZHANG Shu, CHEN Guo-li, LIU Shan, LIAO Xian-wei
DOI: 10.3964/j.issn.1000-0593(2009)01-0169-03
In the present paper, the fluorescence spectra of three common pesticides, isoprocarb, metolcarb and pirimicarb, were theoretically studied. The geometries of these compounds were fully optimized by density function theory (DFT) method at the B3LYP/6-31+G level. The three compounds under study were confirmed as true minima on the potential energy surface in the presence of only real frequencies by the vibrational analysis. The fluorescence spectra were calculated by configuration interaction (CI) method with PCM model, and the results match with the experimental values. The results of calculation suggest that the three compounds with planar structures are hyperconjugation systems. By the addition of the donor-electron groups, the wavelengths of the fluorescence spectra increased, and the frequencies underwent red-shift. In addition, the substitute alkyl has no more influence on the fluorescence spectra, but the addition of amido groups has more influence on the fluorescence spectra.
2009 Vol. 29 (01): 169-171 [Abstract] ( 457 ) PDF (1096 KB)  ( 624 )
172 Synthesis and Fluorescence Properties of Thermo-Responsive Microgel Nanoparticles
ZHAO Hai-feng1,XIONG Wan-bin1,HUANG Xiao-hua1,2,CHEN Ming-qing1*
DOI: 2009-01-0172
In the present paper, the preparation and properties of Eu(Ⅲ) on poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AAc)) were described. At first, P(NIPAM-co-AAc) microgel nanoparticles were prepared by the precipitation copolymerization of N-isopropylacrylamide with acrylic acid in the presence of N,N-methylenebisacrylamide in water. The morphology and size of the P(NIPAM-co-AAc) nanoparticles were characterized by the scanning electron microscope (SEM) method. The result of SEM shows that the sample is uniformly sized spherical particle and the average particle size of the P(NIPAM-co-AAc) is about 365 nm. Then, EuCl3 was chosen to interact with P(NIPAM-co-AAc) nanoparticles and formed the complex of P(NIPAM-co-AAc)-Eu(Ⅲ). The complex was characterized by Fourier transform infrared spectroscopy, ultraviolet-visible and fluorescence spectroscopy. It was found that the complex shows thermo-responsive fluorescence from the experimental results. There exists a energy transfer between the polymer ligand and the Eu(Ⅲ), which can enhance fluorescence emission of the polymer ligand and Eu(Ⅲ) at the same time. The LCST of P(NIPAM-co-AAc) containing Eu(Ⅲ) has changed little after the formation of the complex of P(NIPAM-co-AAc)-Eu(Ⅲ). Therefore, the complex can be used for developing the new applications in biomedical and fluorescence field.
2009 Vol. 29 (01): 172-175 [Abstract] ( 1602 ) PDF (1372 KB)  ( 620 )
176 Influence of Introducing Hexyloxy Group on Fluorescence Property of 4-Nitrostilbene Compounds
CHEN Lan, XIA Xue-wei, LU Jian-mei*,XU Qing-feng, LI Na-jun, WANG Li-hua
DOI: 10.3964/j.issn.1000-0593(2009)01-0176-04
Two new stilbene derivatives, 4-methacryloxyl-4’-nitrostilbene (NS) and 4-(6-methacryloxyl)-hexyloxy-4’-nitrostilbene (HNS), were synthesized and characterized by FTIR, UV-Vis, HPLC and 1H NMR. The influence of structure, concentration and solvent polarity on the fluorescence of the two compounds was investigated in the present paper. Results showed that both NS and HNS have concentration quenching effect and the fluorescence spectrum exhibited a red shift with the increase in the polarity of solvents. Moreover, the donor-acceptor structure is formed in HNS due to the introduction of donor group hexyloxy, which leads to a 72 nm red shift of the maximum wavelength of fluorescence compared with NS, and the fluorescence generated from such composite in DMF solution would change from yellow to orange.
2009 Vol. 29 (01): 176-179 [Abstract] ( 1256 ) PDF (1757 KB)  ( 550 )
180 Fluorescence Studies of Eu Ions Adsorption on Pseudo-Boehmite Colloidal Particle Surface
MENG Yan-shuang1,2,WANG Da-jian3*,WU Jun1,2,LIU Hui-ji1,2,JU Shao-hua1,2
DOI: 10.3964/j.issn.1000-0593(2009)01-0180-04
Stable pseudo-boehmite sol was obtained by adding HNO3 as peptizing agent and adjusting pH to be 2.0. TEM result shows that the AlOOH colloidal particle size is about 60 nm. Field emission transmission electron microscope (FETEM) result shows that pseudo-boehmite colloidal particle is composed of 8nm scaled AlOOH nanocrystals. The interaction of Eu3+ ions and colloidal AlOOH nanoparticle was investigated. The adsorption of Eu3+ ions on the surface of AlOOH nanocrystal was attributed to the chemical adsorption caused by electrostatic attraction. The photoluminescence characters of Eu3+ in AlOOH/Eu(NO3)3 composite sol system were investigated. The 529 nm emission intensity of Eu3+,I592,decreased with the increase in the molar ratio of AlOOH and Eu3+,RBoe/Re. The adsorption ratio (denoted R) and the adsorption density (denoted D) of Eu3+ ions on AlOOH colloidal particle surface was calculated from I592. The results show that the values of R and D increase with increasing RBoe/Re.
2009 Vol. 29 (01): 180-183 [Abstract] ( 1502 ) PDF (1479 KB)  ( 529 )
184 Study on the Interaction of Hesperidin or Icariin with Lysozyme by Fluorescence Spectroscopy
ZHANG Guo-wen, CHEN Xiu-xia, GUO Jin-bao, WANG Jun-jie
DOI: 10.3964/j.issn.1000-0593(2009)01-0184-04
The interaction of hesperidin (HES) or icariin (ICA) and lysozyme (LYS) was studied by fluorescence spectroscopy in physiological buffer solution. It was observed that there was a strong fluorescence quenching effect of hesperidin or icariin on lysozyme. The quenching constants of the drugs with lysozyme were measured at different temperatures, and the quenching mechanism was suggested as dynamic quenching for HES-LYS system and both static and dynamic quenching for ICA-LYS system. The thermodynamic parameters of the interaction of hesperidin or icariin and lysozyme were measured according to the Van’s Hoff equation: the enthalpy change (ΔH) and the entropy change (ΔS) of HES-LYS system and ICA-LYS system were calculated to be 20.29 kJ·mol-1 and 146.28 J·mol-1·K-1,and -3.47 kJ·mol-1 and 81.16 J·mol-1·K-1,respectively, which indicated that the interaction of hesperidin and lysozyme was driven mainly by hydrophobic force, whereas the interaction of icariin and lysozyme was driven mainly by electrostatic force. It was showed that the reaction processes of the two systems occurred spontaneously since Gibbs free energy change (ΔG) values were negative. The binding distances of hesperidin and icariin from the lysozyme tryptophan residue were calculated to be 1.34 nm and 1.24 nm, respectively, based on the Frster’s theory of non-radiation energy transfer. The results of synchronous fluorescence spectra showed that the binding of hesperidin or icariin to lysozyme induced conformational changes in lysozyme.
2009 Vol. 29 (01): 184-187 [Abstract] ( 2507 ) PDF (1632 KB)  ( 687 )
188 Fluorescence Characteristics and Analytical Application of Mn(Ⅱ)-Piperine-Cetyltrimethylammonium Bromide Ternary System
LING Xiao,BORJIHAN Ge-rel-tu*,ZHOU Hai-jun,NA Ri-su
DOI: 10.3964/j.issn.1000-0593(2009)01-0188-04
胡椒碱;锰;溴化十六烷基三甲基胺;荧光光谱
2009 Vol. 29 (01): 188-191 [Abstract] ( 2544 ) PDF (1158 KB)  ( 510 )
192 Fluorescence Spectra of Ponceau-4R
SHI Ai-min1,ZHU Tuo2*,GU En-dong1,LIU Zhou-yi1,XU Hui1
DOI: 10.3964/j.issn.1000-0593(2009)01-0192-04
The fluorescence spectra of ponceau 4R induced by 220-400 nm light were studied in the present paper. The result shows that ponceau 4R has four obvious fluorescence spectral peaks respectively located at 420, 530, 635 and 687 nm, each of these fluorescence spectral peaks has different best induced light, and the corresponding fluorescence spectra were listed. It was considered that this fluorescence comes from the transition nπ* of n electrons in the —OH and π*π of π electrons in the naphthalene. The fluorescence spectral peaks at 420 nm come from the transition nπ* and the other three fluorescence spectral peaks come from π*π. But the intensity of the four fluorescence spectral peaks changes differently with the excited wavelength. This paper attempted to give the expression of the four fluorescence spectral peaks based on the microcosmic mechanism. The reason for that ponceau 4R has complex fluorescence characteristic is that ponceau 4R not only has big and conjugate structure such as naphthalene and provides electron group —OH which can intensify its ability to emit fluorescence, but also absorbs electron group such as NN which can depress its ability to emit fluorescence. Investigation on the fluorescence spectra and its characteristics will contribute to the study on the fluorescence spectra of other azo pigment and help find a new way for checking food safety.
2009 Vol. 29 (01): 192-195 [Abstract] ( 2034 ) PDF (1501 KB)  ( 863 )
196 Study of Retrieving Formaldehyde with Differential Optical Absorption Spectroscopy
LI Yu-jin1,2,XIE Pin-hua1*,QIN Min1,QU Xiao-ying3,HU Lin2
DOI: 10.3964/j.issn.1000-0593(2009)01-0196-05
The present paper introduces the method of retrieving the concentration of HCHO with differential optical absorption spectroscopy (DOAS). The authors measured ambient HCHO in Beijing region with the help of differential optical absorption spectroscopy instrument made by ourself, and discussed numerous factors in retrieving the concentration of HCHO with differential optical absorption spectroscopy (DOAS), especially, the choice of HCHO wave band, how to avoid absorption of ambient SO2,NO2 and O3,and the influence of the Xenon lamp spectrum structure on the absorption of ambient HCHO. The authors achieved the HCHO concentration by simultaneously retrieving the concentrations of HCHO,SO2,NO2 and O3 with non-linear least square fitting method, avoiding the effect of choosing narrow wave of HCHO and the residual of SO2,NO2,O3 and the Xenon lamp spectrum structure in retrieving process to attain the concentration of HCHO, Finally the authors analyzed the origin of error in retrieving the concentration of HCHO with differential optical absorption spectroscopy (DOAS), and the total error is within 13.7% in this method.
2009 Vol. 29 (01): 196-200 [Abstract] ( 1838 ) PDF (2500 KB)  ( 710 )
201 Decomposing Total Suspended Particle Absorption Based on the Spectral Correlation Relationship
WANG Gui-fen1,2,CAO Wen-xi1*,YANG Ding-tian1,ZHAO Jun1,2
DOI: 10.3964/j.issn.1000-0593(2009)01-0201-06
A model for estimating the contributions of phytoplankton and nonalgal particles to the total particulate absorption coefficient was developed based on their separate spectral relationships, and a constrained nonlinear optimization code was used to realize the spectral decomposition. The spectral absorption of total particulate matter including phytoplankton and nonalgal particles was measured using the filter-pad method during two cruises in autumn in Northern South China Sea. Using the dataset collected in 2004, the spectral relationships of particle absorption coefficients were examined and the results showed that the phytoplankton absorption coefficients at various wavebands could be well expressed by aph(443) as the second-order quadratic equations; and the nonalgal particle absorption (aNAP(λ)) could be successfully modeled with the simple exponential function. Based on these spectral relationships, we developed this partition model. The model was tested using the independently measured absorption by phytoplankton and nonalgal materials which were obtained in 2005 from the same area. The test results showed that the computed spectral absorption coefficients of phytoplankton and nonalgal particles were consistent with in situ measurement. Good correlations were found between the computed phytoplankton absorption coefficient and the measured value, with the determination coefficients (r2) being higher than 0.97 and slopes being around 1.0; and the RMSE values could be controlled within 17% over the main absorption wavebands such as 443, 490 and 683 nm. Compared with the other two existing models from Bricaud et al. and Oubelkheir et al., this method shows many advantages for local applications. Moreover, this model does not need any information about pigment concentrations and the selected spectral bands are consistent with the ocean color satellite sensor. This method could also be used in the total absorption coefficient decomposition which provides much insight into the phytoplankton absorption retrieval from in situ measurement and ocean color remote sensing data.
2009 Vol. 29 (01): 201-206 [Abstract] ( 599 ) PDF (1845 KB)  ( 709 )
207 Kinetic Study on the In Situ Synthesis of Nickle Phthalocyanine in Silica Gel Glass Matrix by UV/Vis Absorption Spectra
HUANG Juan, ZHENG Chan, FENG Miao, ZHAN Hong-bing*
DOI: 10.3964/j.issn.1000-0593(2009)01-0207-04
In decades, metallo-phthalocyanines (MPcs) have undergone a renaissance because of their singular and unconventional physical properties. However, for the successful application of MPcs in practical devices, it is important to disperse MPc molecules into solid state matrix to fabricate MPc doped composite with desired properties. Inorganic glass is an ideal matrix because of its transparency and high environmental stability. One attractive approach to fabricating MPc/inorganic composite is sol-gel technique. In the present paper, silica gel glass matrix was prepared by hydrolysis and poly-condensation of tetraethyloxysilane. 1,2-dicyanobenzene and analytically pure soluble nickle salt were used as the nickle phthalocyanine (NiPc) reactants and chemical synthesis technique was used to prepare NiPc doped sol-gel materials at several temperatures. During the heat treatment, four 1,2-dicyanobenzene molecules and one nickle ion collide to form a NiPc molecule. In-situ synthesizing process of NiPc in the pores of silica gel glass matrix was traced by UV/Vis absorption spectra. Owing to the remarkable absorption band of NiPc in visible region, quantity of in-situ synthesized NiPc was calculated by the absorbance at certain wavelength of 670 nm, using composites with physically doped NiPc as a reference. The in-situ synthesized kinetics was studied in detail and found to be consistent with Avrami-Erofeev equation. The reaction grades were deduced to be 4.5, 4.5, 3.7, 3.2 and 1.9 respectively at temperatures of 180 ℃, 185 ℃, 190 ℃, 195 ℃ and 200 ℃, respectively.
2009 Vol. 29 (01): 207-210 [Abstract] ( 245 ) PDF (1693 KB)  ( 636 )
211 Comparative Study on Selenium and Amino Acids Content in Leaves of Planted and Wild Scutellaria Baicalensis
SHENG Ji-ping, CHEN Hai-rong, SHEN Lin*
DOI: 10.3964/j.issn.1000-0593(2009)01-0211-03
Scutellaria baicalensis is one of the most important Chinese herbs. It is widely used in Asian medicine to improve impaired brain function and to treat headaches, and used to treat prostate cancer. It is also known to be anti-inflammatory and antifungal, and also seems to have antiviral properties, including possible effectiveness against HIV. Scutellaria baicalensis tea and other products are in development. In the present study, the content of selenium (Se) in leaves of planted and wild Scutellaria baicalensis was determined by fluorescence photometer. The contents of 18 kinds of amino acids in the leaves of planted and wild Scutellaria baicalensis were determined with amino acids instruments. The results showed that the two kinds of leaves were rich in Se content, and the content of Se in planted Scutellaria baicalensis (0.051 μg·g-1) was not significantly different from that in wild one (0.051 μg·g-1,α=0.05). The amino acids, of which the total content was up to 14.62% and 10.25% separately, were rich in both planted and wild Scutellaria baicalensis. Among the 18 kinds of amino acids, aspartic acid, glutamic acid and leucine were comparatively high in leaves of planted and wild Scutellaria baicalensis. There are 8 kinds of amino acids essential to human body, which were higher in leaves of planted Scutellaria baicalensis than those of wild one. This study, for the first time, determined Se and amino acids content in Scutellaria baicalensis and concluded that the leaves of planted type have Se and amino acids content not lower or higher than that of wild type, and the planted type could be a good substitute of wild type in the development of Scutellaria baicalensis products. This study also provided useful data for explaining the multifunction of Scutellaria baicalensis and theological basis for developing its medical and edible value.
2009 Vol. 29 (01): 211-213 [Abstract] ( 705 ) PDF (955 KB)  ( 507 )
214 Immune Resonance Scattering Spectral Analysis of Fenvalerate
MA Wen-sheng1,WANG Su-mei2,JIANG Zhi-liang1,2*
DOI: 10.3964/j.issn.1000-0593(2009)01-0214-03
In the pH 7.2 Na2HPO4-NaH2PO4 buffer solutions and in the presence of PEG-6000, fenvalerate (Fen) antisera was combined with Fen specifically, and aggregated to form immune complex particles that exhibited five resonance scattering peaks at 350, 390, 420, 440 and 480 nm respectively. The peak at 390 nm was the strongest and was chosen for use. Fen concentration (c) in the range of 0.20 to 6.40 μg·mL-1 was proportional to the resonance scattering intensity at 390 nm. Its regression equation was ΔIRS=23.05c-1.39, the correlation coefficient was 0.997 8, and the detection limit was 0.07 μg·mL-1. Effects of buffer solution type, pH value, buffer solution volume, fenvalerate antisera concentration, PEG-6000 concentration, incubation temperature and time on the resonance scattering intensity were considered in detail. With pH(5.8-8.0)increasing, the IRS and Ib all decreased. When the pH value was at 7.2, the ΔIRS was bigger. Three buffer solutions of pH 7.2, including Na2HPO4-citric acid, Na2HPO4-KH2PO4 and Na2HPO4-NaH2PO4,were examined. The pH 7.2 Na2HPO4-NaH2PO4 buffer solution gives the biggest ΔIRS value. PEG-6000 could enhance the ΔIRS value. When the concentration of PEG-6000 was 50.0 mg·mL-1,the ΔIRS was achieved at max. Fen was a stable chemical. The IRS increased within 20 min,while the ΔIRS remained constant when incubation time was in the range of 20-40 min. The condition of a pH 7.2 Na2HPO4-NaH2PO4 buffer solution-50.0 mg·mL-1 PEG-6000-6.67 μg·mL-1 Fen antisera-30 ℃-incubation time 20 min was chosen. According to the procedure, the influence of foreign substances on the determination of 1.60 μg·mL-1 Fen was examined,within a relative error of ±5%. Results showed that the following coexistent substances had no impact on the RS assay: 96 μg·mL-1 ametryne, 96 μg·mL-1 m-aminotoluene,48 μg·mL-1 simetryne, 48 μg·mL-1 p-aminotoluene,80 μg·mL-1 BSA, 80 μg·mL-1 HSA, 80 μg·mL-1 Fe3+,80 μg·mL-1 Mg2+,160 μg·mL-1 Ca2+,and 160 μg·mL-1 glucose. The results indicated that this RSS assay has good selectivity. This immune resonance scattering spectral assay was applied to the determination of Fen in waste water samples with satisfactory results. The recovery was in the range of 92.91%-101.25%, and the relative standard deviation was in the range of 1.71%-4.80%.
2009 Vol. 29 (01): 214-216 [Abstract] ( 2880 ) PDF (1046 KB)  ( 504 )
217 Research on Particle Size and Size Distribution of Nanocrystals in Urines by Laser Light Scattering Method
WAN Mu-hua, ZHAO Mei-xia, OUYANG Jian-ming*
DOI: 10.3964/j.issn.1000-0593(2009)01-0217-05
In the present paper laser light scattering method was used to investigate the particle size and size distribution of nanoparticles simultaneously in urines of lithogenic patients and healthy persons. This method is economic, rapid, accurate and easy to operate. The results showed that healthy urines are more stable than lithogenic urines. In urines of healthy human, the ultrafine crystals were well scattered and not aggregated with a smaller size. However, the ultrafine crystals in lithogenic urine have a broad size distribution, which increases the aggregation trend of nanocrystals. Based on the intensity-autocorrelation curve, the stability of urine samples of both healthy human and lithogenic patients was comparatively investigated. The relationship between the measurement results and the methods of handling sample was studied. The results show that a stable urine sample can be obtained by diluting the urine with a ratio of 20%, then centrifuging it at 4 000 round per minute for 15 minutes or filtrating it with 1.2 μm cellulose acetate filter. The results of laser light scattering method are consistent with that obtained by transmission electron microscopy (TEM). The reasons for the stability of urines are explained from the points of Van der Waals force, urine viscosity, pH value, ionic strength, surface charge and zeta potential of the ultrafine crystals, and so on. The results in this paper provide a new thought for preventing formation and recurrence of urinary stones.
2009 Vol. 29 (01): 217-221 [Abstract] ( 1194 ) PDF (1594 KB)  ( 579 )
222 Study on Application of Multi-Spectral Image Texture to Discriminating Rice Categories Based on Wavelet Packet and Support Vector Machine
CHEN Xiao-jing1,2,WU Di1,HE Yong1*,LIU Shou2
DOI: 10.3964/j.issn.1000-0593(2009)01-0222-04
Based on multi-spectral digital image texture feature, a new rapid and nondestructive method for discriminating rice categories was put forward. The new method combined the advantages of wavelet packet and support vector machine (SVM). In the present study, the images which are 1 036 pixels in vertical direction by 1 384 pixels in horizontal direction with 24-bit depth were captured using a red (R) waveband, near infrared (NIR) waveband and green (G) waveband multi-spectral digital imager. The three wavebands of image (red, green and NIR) can be composed into one image which contains more information than images captured by ordinary digital cameras, and the NIR image can catch more information than visible spectrum. NIR waveband images were decomposed to 16 subbands using three wavelet packet multi-resolution. Because the main feature of texture information is concentrated on the middle frequency, the 8 subbands of middle frequency were selected to calculate entropy, and the entropy of three wavebands of original image was calculated at the same time. Eighty images (twenty for each category) were used for calibration set and eighty images (twenty for each category) were used as the prediction set. Then the rice categories were classified by SVM. The classification rate of rice categories was only 93.75% using the entropy of original image, but reached 100% by wavelet packet decomposition. The overall results show that the technique combining wavelet packet and support vector machine can be efficiently utilized for texture recognition of multi-spectra, and is an effective and simple technique for discriminating the rice categories. This study also provides a foundation for rice grading and other rice industry processing such as quality diction and milling degree.
2009 Vol. 29 (01): 222-225 [Abstract] ( 1421 ) PDF (1293 KB)  ( 1036 )
226 Spectroscopic Study on the Interaction between Resveratrol and Human Serum Albumin
WU Qiu-hua, ZHOU Xin, ZANG Xiao-huan, WANG Chun, ZHANG Zhi-heng, WANG Zhi*
DOI: 10.3964/j.issn.1000-0593(2009)01-0226-05
The interaction between resveratrol and human serum albumin (HSA) was studied by using fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. The Stern-Volmer curve of the fluorescence quenching of HSA by resveratrol indicated that the quenching mechanism between resveratrol and HSA was mainly static quenching, with nonradiation energy transfer occurring within single molecule. The binding constants (KA) were 2.39×105 (25 ℃),1.25×105 (35 ℃) and 1.10×105 (45 ℃), respectively. According to the Frster theory of nonradiation energy transfer, the binding distances (r) were 3.02 nm (25 ℃), 3.46 nm (35 ℃) and 3.79 nm (45 ℃), respectively. The thermodynamic parameters showed that the interaction between resveratrol and HSA was mainly driven by hydrophobic force. Synchronous spectrum was used to investigate the conformational change of HSA.
2009 Vol. 29 (01): 226-230 [Abstract] ( 1747 ) PDF (1552 KB)  ( 614 )
231 Preliminary Study on the Function of Potteries of Liangzhu Culture
LI Nai-sheng1,LI Qing-lin2*,YAO Zheng-quan3,MAO Zhen-wei4
DOI: 10.3964/j.issn.1000-0593(2009)01-0231-05
Liangzhu Culture is an important late neolithic culture of China, but there are different opinions on the function of some potteries of Liangzhu Culture, for example vat and Ding. In the present paper, for discussing the function of these potteries, the content of Cl, Ca and P of some shard samples of vat and Ding from Liangzhu site were analyzed by using EDXRF line scanning technology. The results show that the content of element Cl in the outside and inside parts of the bottom of vat sample is not different from that of other contemporaneous archaic potteries, and that the distribution of element Cl in the outside part of the bottom of vat sample is the same as that in the inside part of the bottom, so it is concluded that the function of vat from Liangzhu Culture is not related to the production or storage of salt, but with regard to the true function of this pottery more works remain to be done. The analytical results also show that the content of two elements, Ca and P, in the bottom of the other pottery, Ding, is obviously higher than that in vat and other contemporaneous archaic potteries, and that the content of two elements, Ca and P, in the outside part of the bottom of Ding sample is higher than that in the inside part of the bottom. So it is concluded that Ding from Liangzhu Culture is a kind of cooking ware and its main function is meal cooking.
2009 Vol. 29 (01): 231-235 [Abstract] ( 1907 ) PDF (1921 KB)  ( 574 )
236 Studies on the Reaction of Norfloxacin with Ovalbumin
LU Xiu-min,CHEN De-jun,WANG Gong-ke,YANG Hai-yan,LU Yan*
DOI: 10.3964/j.issn.1000-0593(2009)01-0236-04
The interaction between norfloxacin (NRF) and ovalbumin (OVA) was studied by fluorescence and absorption spectroscopy. The binding constants and the binding sites were measured by fluorescence quenching method. It was found that the emission peak of OVA was positioned at 338 nm. When the norfloxacin was added into OVA solution gradually, the intensity of 338 nm emission peak of OVA decreased obviously and moved towards long wavelength. The experiment demonstrated that the higher the temperature, the lower the slopes of quenching curves of OVA in the presence of different amounts of NRF. It was confirmed that the combination of NRF with OVA is a single static quenching process. With the increase in the pH of the solution, the quenching efficiency decreased in the binding. From thermodynamic parameters, it can be judged that the binding power between OVA and NRF is electrostatic effect and H-bond formation. The UV-Vis absorption spectra of OVA in the presence of NRF show that the conformation of OVA changed.
2009 Vol. 29 (01): 236-239 [Abstract] ( 1234 ) PDF (1340 KB)  ( 581 )
240 Application and Development of Spectroscopy Methodologies in the Study on Non-Covalent Interactions
LI Rui1,DAI Ben-cai1,ZHAO Yong-de1*,LU Kui2
DOI: 10.3964/j.issn.1000-0593(2009)01-0240-04
Spectrophotometric method is widely used in the structure determination of biologic macromolecules and non-covalent interactions study for its convenience and speed. In the present paper, spectroscopy methodologies in the study of non-covalent interactions between small-molecule and biomacromolecule is comprehensively reviewed with 25 references.This review article focuses on the applications and development of common spectroscopy methodologies in the study of non-covalent interactions between small molecule and biomacromolecule,including the UV, fluorescence, CD, IR, Raman, resonance light scattering technique and SPR. The advantages and disadvantages of spectroscopy methodologies are also described. UV-Vis absorption spectrum (UV) method is widely used in the study of non-covalent interactions for its convenience and speed. The binding site number, the apparent binding constant and the interaction mode of non-covalent interactions can be obtained by fluorescence spectrum method. Circular dichroism (CD) method is effective way in the study of non-covalent interactions measure. Spectroscopy information about protein secondary structure and conformation can be acquired by infrared spectrometry (IR) method. Raman spectroscopy method is a better way to investigate the conformation change in macromolecules in solution. Non-covalent interactions can be measured by surface plasma resonance (SPR) method under the natural active condition. X-ray diffraction analysis method is better for non-covalent interactions research, but it is difficult to cultivate crystalline complex.
2009 Vol. 29 (01): 240-243 [Abstract] ( 2196 ) PDF (962 KB)  ( 958 )
244 Effect of Charge Compensation on Emission Spectrum of Sr2SiO4∶Dy3+ Phosphor
LI Pan-lai, WANG Zhi-jun*,YANG Zhi-ping, GUO Qing-lin
DOI: 10.3964/j.issn.1000-0593(2009)01-0244-03
The Sr2SiO4∶Dy3+ phosphor was synthesized by the high temperature solid-state reaction method in air. Dy2O3(99.9%), SiO2(99.9%), SrCO3(99.9%), Li2CO3(99.9%), Na2CO3(99.9%) and K2CO3(99.9%) were used as starting materials, and the Dy3+ doping concentration was 2 mol%. The emission spectrum was measured by a SPEX1404 spectrophotometer, and all the characterization of the phosphors was conducted at room temperature. The emission spectrum of Sr2SiO4∶Dy3+ phosphor showed several bands centered at 486, 575 and 665 nm under the 365 nm excitation. The effect of Li+,Na+ and K+ on the emission spectra of Sr2SiO4∶Dy3+ phosphor was studied. The results show that the location of the emission spectrum of Sr2SiO4∶Dy3+ phosphor was not influenced by Li+,Na+ and K+. However, the emission spectrum intensity was greatly influenced by Li+,Na+ and K+,and the evolvement trend was monotone with different charge compensation, i.e. the emission spectrum intensity of Sr2SiO4∶Dy3+ phosphor firstly increased with increasing Li+ concentration, then decreased. However the charge compensation concentration corresponding to the maximum emission intensity was different with different charge compensation, and the concentration is 4, 3 and 3 mol% corresponding to Li+,Na+ and K+,respectively. And the theoretical reason for the above results was analyzed.
2009 Vol. 29 (01): 244-246 [Abstract] ( 457 ) PDF (1451 KB)  ( 786 )
247 Comparative Study of Minerals and Some Nutrients in Organic Celery and Traditional Celery
SHENG Ji-ping, LIU Can, SHEN Lin*
DOI: 10.3964/j.issn.1000-0593(2009)01-0247-03
Conventional cultivation pattern, integrated cultivation pattern and organic cultivation pattern are three patterns in China, and organic produce from organic cultivation pattern is considered the best one in quality and safety. Some experiments have been done on the effect of different cultivation patterns on the vegetable quality, such as the contents of Vc, total sugar, and dissoluble solid, which show the organic cultivation pattern and integrated cultivation pattern excel the conventional cultivation pattern, but there are no data that show the difference in the contents of mineral elements. In the present study, the contents of nutritional elements such as Ca, Mg, K, Zn, Fe and Mn and heavy elements such as Cu, Cd and Pb in organic celery and traditional celery were analyzed by ICP-OES, and the contents of some nutritional ingradients such as water, total soluble solid, soluble sugar and asorbic acid were also investigated. The results showed that the contents of K and Zn in organic celery were respectively 70.22% and 47.93% higher than that in traditional celery, but there was no significant difference in the contents of Ca, Mg and Fe, while the content of Mn was 47.24% lower in organic celery (α=0.05). The contents of Cu, Cd and Pb showed no significant difference between the two kinds of celery, and are lower than the national requirement. The content of water and total soluble solid showed no significant difference, whereas the contents of soluble sugar and asorbic acid in organic celery were 55.04% and 118.18% higher, respectively. The difference in the nutritional ingredients and mineral elements and safety status between the two kinds of celery provides academic data for the comparison between organic vegetables and traditional ones.
2009 Vol. 29 (01): 247-249 [Abstract] ( 302 ) PDF (1002 KB)  ( 534 )
250 Study on testing methods of Al Content of Polyimide Hybrid Films with Al2O3
ZHOU Hao-ran, LIN Fei, ZHAO De-ming, LIU Xin-gang, FAN Yong
DOI: 10.3964/j.issn.1000-0593(2009)01-0250-06
The inorganic particles hybrid polyimide films are newly emerging advanced materials with excellent corona-resistant and have been widely used in frequency control motor. The Al2O3/PI hybrid films with different Al2O3 contents were prepared by superfine aluminum power treated by coupling agent and polyamide acid (PAA). Qualitative analysis and quantitative analysis on the inorganic content to it were conducted using Fourier Transform Infrared Spectroscope (FTIR), X-ray photoelectron spectroscopy (XPS), Inductively coupled plasma spectrometry (ICP), Gravimetric method, Thermogravimetric Analysis (TG/air atmosphere). It was found that FTIR and XPS are good qualitative analysis methods. FTIR is used to inference possible components by analyzing the structure of material. The method has a lot of advantages such as easily operational, good repeatability, high accuracy and so on. XPS is mainly used to get information of elements contained in the material, it provides information about the core level binding energies and oxidation states of complexes. It can be used to identify the species and valence states of elements, measure the relative content of elements. The relative standard deviations (RSDs) of XPS and TG are too great to perform quantitative analysis, the RSDs of XPS are all above 5.0%, and TG’s RSDs are also above 2.0%. So they can be only used as semiquantitative analysis methods. On the contrary, ICP and Gravimetric method are two excellent quantitative analysis methods, their RSDs are all below 1.0%. Moreover Gravimetric method only can be used to analyze single inorganic constituent complex material, although its measured value is closest approach to theoretical value. ICP is the most accurate method and it can be used to analyze multi inorganic components in complex material, this method proved to be easily operational, rapid, highly sensitive, and accurate, and can be adopted as the method of determining many elements simultaneously. So a method was got to analysis of inorganic constituent in complex material from the conclusion upward. Firstly, components in complex material are defined by using FTIR and XPS as qualitative analysis methods and then using the result of XPS as a reference, exactly quantitative analysis of inorganic constituent in complex material was performed by using Gravimetric method and ICP.
2009 Vol. 29 (01): 250-255 [Abstract] ( 1916 ) PDF (1505 KB)  ( 858 )
256 Determination of U, Th and Tl in Fourteen Chinese Traditional Medicines by Microwave Digestion-ICP-MS
SUN Wei-min1,XUE Da-fang2,LI Hong1,LIU Hui1,TENG Wen-feng1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0256-03
Fourteen Chinese traditional medicines were digested by microwave digestion, which are generally applied to treat tumor in clinic, and the contents of U, Th and Tl in the fourteen Chinese traditional medicines were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the results show that the change ranges of the elements contents were: 0.005 153-0.153 4 μg·g-1 for U;0.035 01-0.462 8 μg·g-1 for Th;0.001 43-1.600 μg·g-1 for Tl. The contents of U, Th and Tl in the fourteen Chinese traditional medicines were low, and not with one accord. The determination results of the fourteen Chinese traditional medicines were analyzed by SPSS 11.5, and the results show that there were not significant deviations(p>0.05) of the contents of U, Th and Tl between the medicine of treating the toxifying disease with poisonous agents and the medicines of heat-clearing. The study indicates that inductively coupled plasma mass spectrometry (ICP-MS) is a quick, accurate, sensitive method to determine the contents of U, Th and Tl in Chinese traditional medicine, and the results of this study provide reference data for using Chinese traditional medicine safely in clinic and developing Chinese traditional medicine.
2009 Vol. 29 (01): 256-258 [Abstract] ( 1205 ) PDF (957 KB)  ( 637 )
259 The Characteristic Analysis of Several Mineral Contents in Chinese Orange Juice
NIU Li-ying1,HU Xiao-song1,ZHAO Lei2,LIAO Xiao-jun1,WANG Zheng-fu1,WU Ji-hong1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0259-04
A study was carried out on the contents of mineral elements such as K, Ca, Na, and Mg in seven different orange varieties, namely Pineapple orange, Hamlin, Trovita, Jincheng, 1 232 Tangor, Olinda Valencia and Delta Valencia, by flame atomic absorption spectrometry. The results indicated that the content sequence of different nutritional elements was K>Mg>Ca>Na, with a range of 1 233.75-1 866.23, 77.51-167.15, 49.32-125.29 and 1.22-9.26 mg·L-1 respectively. The range scale of the four elements was largely consistent with the reference value of AIJN (Association of the Industry of Juices and Nectars from Fruits and Vegetables of the European Union). The samples can be clustered into 2 groups by factor analysis, and lower Na content would be the characteristic of the Valencia varieties. All these data would offer important information for orange juice adulteration determination and quality evaluation.
2009 Vol. 29 (01): 259-262 [Abstract] ( 1141 ) PDF (1411 KB)  ( 555 )
263 Determination of Lithium in the Oil Field Water by Flame Atomic Absorption Spectrometry
YANG Hong-jun1,2,YE Xiu-shen1,2,LI Bing1,WU Zhi-jian1,LI Wu1*
DOI: 10.3964/j.issn.1000-0593(2009)01-0263-05
Flame atomic absorption spectrometry was applied to the determination of micro amount of lithium in the oil field water of certain area. In order to determine which method is more appropriate for the determination of lithium content in the oil field water, standard curve method and standard addition method were compared. The effects of dilution, coexistent ions, and deionizers on the determination were studied. For the determination of lithium content in the same diluted oil field water samples, there exist obvious differences between the results obtained from standard addition method and standard curve method. Standard addition method gives results with a larger error, whereas standard curve method gives more accurate results. It is difficult to eliminate the interferences when the standard addition method is used. The standard curve method is found to be more suitable for the determination of micro amount of lithium in the oil field water for its accuracy, simplicity, and feasibility. When the standard curve method is used, both the determined lithium concentration and the recovery change with the dilution extent of the oil field water. In order to get an accurate result, the oil field water sample should be diluted to 1/200 or less. In this case, the recovery by standard addition method ranges from 94.3% to 96.9%. When sodium phosphate or sodium chloride is used as the deionizer, the recovery by standard addition method ranges from 94.6% to 98.6%, or from 94.2% to 96.3%. In the determination of lithium content in oil field water, there are larger experimental errors without the addition of any deionizer. When the concentration of coexistent ions is within an allowed range, the addition of sodium phosphate as a deionizer can eliminate the interferences of the coexistent ions with the determination of the lithium content. If sodium chloride is used as a deionizer, a more accurate result can be obtained when the sodium content in the samples is near the sodium content in the standard solutions. In general, under suitable experimental conditions, sodium chloride can be used as the deionizer for the determination of lithium content in the oil field water.
2009 Vol. 29 (01): 263-267 [Abstract] ( 1657 ) PDF (1018 KB)  ( 638 )
268 XPS and Raman Spectral Analysis of Nitrogenated Tetrahedral Amorphous Carbon (ta-C∶N) Films with Different Nitrogen Content
CHEN Wang-shou, ZHU Jia-qi*,HAN Jie-cai, TIAN Gui, TAN Man-lin
DOI: 10.3964/j.issn.1000-0593(2009)01-0268-05
Nitrogenated tetrahedral amorphous carbon (ta-C∶N) films were prepared on the polished C—Si substrates by introducing highly pure nitrogen gas into the cathode region and the depositing chamber synchronously using filtered cathodic vacuum arc (FCVA) technology. The nitrogen content in the films was controlled by changing the flow rate of nitrogen gas. The configuration of ta-C∶N films was investigated by means of X-ray photoelectron spectroscopy (XPS) and visible Raman spectroscopy. It was shown that the nitrogen content in the films increased from 0.84 at% to 5.37 at% monotonously when the nitrogen flow rate was varied from 2 sccm to 20 sccm. The peak position of C(1s) core level moved towards higher binding energy with the increase in nitrogen content. The shift of C(1s) peak position could be ascribed to the chemical bonding between carbon and nitrogen atoms even though more three-fold coordinated sp2 configuration as in graphite was formed when the films were doped with more nitrogen atoms. Additionally, the half width of C(1s) peak gradually was also broadened with increasing nitrogen content. In order to discover clearly the changing regularities of the microstructure of the films, the XPS C(1s) spectra and Raman spectra were deconvoluted using a Gaussian-Lorentzian mixed lineshape. It was shown that the tetrahedral hybridization component was still dominant even though the ratio of sp2/sp3 obtained from C(1s) spectra rose with the increase in nitrogen content. The Raman measurements demonstrated that the G peak position shifted towards higher frequency from 1 561 to 1 578 cm-1 and the ratio of ID/IG also rose with the increase in nitrogen content. Both results indicated that the graphitizing tendency could occur with the increase in nitrogen content in the films.
2009 Vol. 29 (01): 268-272 [Abstract] ( 509 ) PDF (1574 KB)  ( 750 )
273 Effect of Urinary pH Value on the Composition of Urinary Nanocrystals
XU Xiao-jing, WAN Mu-hua, OUYANG Jian-ming*
DOI: 10.3964/j.issn.1000-0593(2009)01-0273-04
The effect of urinary pH value on the composition of urinary nanocrystals was investigated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The differentiation of composition of urinary nanocrystals not only occurred between the people with different urinary pH, but also occurred in the same person when his or her urinary pH changed. At lower urinary pH (such as pH<5.8), most of the urinary components are uric acid, acidic phosphate, calcium oxalate etc. However, most of these components are urate, phosphate, magnesium ammonium phosphate, calcium oxalate etc at higher urinary pH (such as pH>6.2). Combining XRD and FTIR methods, the compositions of urinary nanocrystals can be determined accurately. It is helpful to exploring the cause of urinary stones.
2009 Vol. 29 (01): 273-276 [Abstract] ( 1671 ) PDF (1442 KB)  ( 598 )
277 Microanalysis Study of Co-Doped ZnO DMS Crystal by SEM and XREDS
QIU Man-de1,YAO Zi-hua1,WEI Zhi-ren2,ZHAI Yong-qing1,TIAN Shuai2,ZHANG Shuang1
DOI: 10.3964/j.issn.1000-0593(2009)01-0277-04
In the present paper,with CoCl2·6H2O used as precursor, Co-doped ZnO diluted magnetic semiconductor(DMS)crystals were synthesized by hydrothermal method with KOH as mineralizer. The morphology, and the relative content and distribution uniformity of the surface and inner Co element of synthesized crystals were investigated by scanning electron microscope (SEM) and X-ray energy dispersive spectrometry (XREDS), respectively. It was found that Co-doped ZnO crystals with different morphology were yielded, while the bigger crystals showed polar growth charactertistics, and the Co content in the crystal depended on its morphology. The exposed face also changed with crystal morphology. There was more Co in bigger crystals than in smaller ones. Moreover, more Co located in +c(1011)compared to +c (1010)exposed face, especially for cone crystals. In addition, it was observed that there was a little amount of cobalt oxide cluster in inner crystal,and the distribution of Co content was relative uniform in both the surface and inner part of the crystal. Cobalt oxide cluster may have effect on the magnetic properties of Co-doped ZnO diulted magnetic semiconductor since Co2+ possesses magnetic property.
2009 Vol. 29 (01): 277-280 [Abstract] ( 756 ) PDF (1518 KB)  ( 705 )
281 Global Modeling and Analyzing of Grating Spectrometers
YANG Huai-dong, CHEN Ke-xin, HUANG Xing-yue, HE Qing-sheng, JIN Guo-fan
DOI: 10.3964/j.issn.1000-0593(2009)01-0281-04
A method for globally modeling and analyzing grating spectrometers is put forward in the present paper. Different from existing methods which are confined to parts of a spectrometer, the method takes a grating spectrometer as four functional parts, namely imaging optics, detector, reconstruction and display. Effects of each part on spectrum are considered and a global model of the spectrometer is developed, accompanied with its transfer function. With the help of the model and the transfer function, laws of each part affecting the holistic performance are summed up. It is suggested that high quality spectrogram needs enhancing baseband response and reducing spurious response, and reconstruction is an effective way.
2009 Vol. 29 (01): 281-284 [Abstract] ( 884 ) PDF (1182 KB)  ( 592 )