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2009 Vol. 29, No. 06
Published: 2009-06-01

 
       光谱学与光谱分析
1441 Research on AlInGaN Quaternary Alloys as MQW Barriers in GaN-Based Laser Diodes
CHEN Wei-hua1, LIAO Hui1,HU Xiao-dong1*, LI Rui1, JIA Quan-jie2, JIN Yuan-hao3,DU Wei-min3, YANG Zhi-jian1, ZHANG Guo-yi1
DOI: 10.3964/j.issn.1000-0593(2009)06-1441-04
InGaN/GaN, InGaN/InGaN and InGaN/AlInGaN multi-quantum-well (MQW) laser diodes (LDs) were grown on (0001) sapphire substrate by metalorganic chemical vapor deposition (MOCVD). The GaN (0002) synchrotron X-ray diffraction (XRD), electroluminescence (EL) and optical power-current (L-I) measurement reveal that AlInGaN quaternary alloys as barriers in MQWs can improve the crystal quality, optical emission performance, threshold current and slope efficiency of the laser diode structure to a large extent compared with other barriers. The relevant mechanisms are that:1. The Al component increases the barrier height of the MQWs so that more current carriers will be caught in. 2. The In component counteracts the strain in the MQWs that decreases the dislocations and defects, thereby the nonradiative recombination centers are decreased. 3. The In component decreases the piezoelectric electric field that makes the electrons and the holes recombine more easily.
2009 Vol. 29 (06): 1441-1444 [Abstract] ( 2010 ) PDF (953 KB)  ( 427 )
1445 Applications of Terahertz Spectroscopy and Imaging Techniques in Food Safety Inspection
SHEN Fei, YING Yi-bin*
DOI: 10.3964/j.issn.1000-0593(2009)06-1445-05
With the development of ultra-fast laser technology and the further understanding of the mechanism behind the interaction of terahertz radiation and materials, THz radiation is actively developed as a new-style technology for a wide range of applications. Currently THz spectroscopy and imaging techniques show great promise in security detection, medical diagnosis, wireless communication, pharmaceutical and many other areas. Because of the growing importance of food safety issues, the detection technology of food safety is also faced with great opportunities and challenges, while THz spectroscopy and imaging techniques provide a new solution to the problem. Compared to other technologies, THz radiation with higher signal-to-noise ratio and wide dynamic range can simultaneously obtain both frequency-domain and time-domain information of the sample which relates to the information of physical structure and chemical composition of materials. Above all THz radiation features unique advantages in food safety inspection. In the present paper, the brief concept of terahertz radiation was introduced, while the properties and technical methods of THz wave were also discussed. The most recent progress in THz technology used in food safety inspection was summarized. The prospect and restricted factors of this novel technology in food industry were also discussed.
2009 Vol. 29 (06): 1445-1449 [Abstract] ( 389 ) PDF (970 KB)  ( 445 )
1450 A Method for Resolving Spectra Shift in the Urban Air Quality Monitoring System (DOAS)
LIU Shi-sheng, WEI Qing-nong,FENG Wei-wei, ZHAN Kai, WANG Feng-ping
DOI: 10.3964/j.issn.1000-0593(2009)06-1450-04
In the urban air quality monitoring system, there is spectra shift which is caused by environment factors on the optical part (temperature and optic fiber position), or by the self-change of Xe-lamp. Relative spectra shift will occur if the shift of lamp-spectrum and air-spectrum is inconsistent which has direct influences on the accuracy of the measurement results. So the match of wavelength between lamp-spectrum and air-spectrum should be considered when we retrieve pollutants concentration measurement of trace gas in the atmosphere through DOAS method. Based on the study of the unique structures for Xe-lamp emitting spectrum, a method for the calibration of two signal spectra using Xe-lamp emitting peak and least square fitting is given. The results show that, the impact of spectrum shift can be reduced by this method for retrieving results.
2009 Vol. 29 (06): 1450-1453 [Abstract] ( 1584 ) PDF (898 KB)  ( 455 )
1454 Micro- and Nano-Structures on Metal Induced by Femtosecond Laser Radiation
ZHOU Ming, YUAN Dong-qing, LI Jian, FAN Xiao-meng, DAI Juan, SHEN Jian, WANG Hui, LI Bao-jia, CAI Lan
DOI: 10.3964/j.issn.1000-0593(2009)06-1454-05
In the present study the authors performed surface treatment of stainless steel 65Mn (the thickness is 60 μm) by femtosecond laser (pulse duration 148 fs, wavelength 775 nm). The single-pulse threshold could be obtained directly to be about 0.2 J·cm-2. The authors found that the femtosecond laser produced a large number of micro-structures such as nano-pores and nano-protrusions. Then the authors discussed the influence of pulse power and the number of shots on the formed surface structures. The authors found that with the change in the power and the number of pulses, the period of multiple parallel grooved surface patterns remained unchanged, which is about on the sub-micron level. Finally the authors processed the array of holes and the lines with different speed and number of pulses.
2009 Vol. 29 (06): 1454-1458 [Abstract] ( 1210 ) PDF (1832 KB)  ( 417 )
1459 Time-Resolved Photoluminescence of Stimulated Emission from ZnO Nanoparticles
WANG Xiao-fang1, XIE Ping-bo1, ZHAO Fu-li2, WANG He-zhou2
DOI: 10.3964/j.issn.1000-0593(2009)06-1459-04
The detailed room-temperature stimulated emission including its optical characteristics from nanosized ZnO particles prepared by homogenous precipitation method was investigated by time-resolved spectroscopy both from the frequency domain and time domain. As the excitation power was increased, sharp lasing peaks with the full width at half maximum less than 0.5 nm, similar to the FP lasing mode resonator mode, emerged rapidly from the emission spectra. Additionally, a narrow emission line intensity increased rapidly with increasing the excitation intensity,which was due to an exciton-exciton collision recombination, and the threshold excitation intensity was 7.2 GW·cm-2. Upon higher excitation power, the lasing mechanism switched to electron-hole plasma (EHP). The EHP emission in the case of a higher excitation intensity appeared at a lower energy side of the E-E emission and replaced completely the E-E emission at the higher intensity. The EHP emission was red-shifted when further increasing the excitation intensity, compared to the E-E emissions. It was demonstrated that the red-shift of the EHP peak was attributed to the relevant band gap renormalization effect in the electron-hole plasma regime. At the same time, the emission lifetime was drastically reduced. Time-resolved spectrum of P band suggested a Gaussian-like decay time with only a few tens of picoseconds, compared to 2 ps, which is the limit of streak camera time resolution. The dynamic processes of lasing behavior and characteristics of the lasing emission in ZnO nanoparticles could be valuable and provide the information on crystal quality, exciton and lasing action in ZnO.
2009 Vol. 29 (06): 1459-1462 [Abstract] ( 2052 ) PDF (895 KB)  ( 412 )
1463 Study of CO2 Spectroscopic Parameters at High Temperature near 1.57 μm
CAI Ting-dong1, WANG Gui-shi1, CHEN Wei-dong2, ZHANG Wei-jun1, GAO Xiao-ming1
DOI: 10.3964/j.issn.1000-0593(2009)06-1463-05
Measurements strategies based on absorption spectroscopy techniques, especially the measurements in high temperature, require accurate values of important spectroscopic parameters of the probed species. Sometimes the parameters listed in widely used HITRAN and HITEMP2004 database are uncertain to some extent. In order to validate the spectroscopic parameters of 9 selected CO2 lines which should be used in combustion diagnosis, spectra of those lines were recorded in a high temperature experiment setup as a function of temperature (in the range of 300-800 K) and pressure (in the range of 9-450 torr) using a distributed feed-back (DFB) diode laser. The recorded absorption spectra were fitted to Voigt profile. Line intensity, air-broadening coefficient and temperature exponent of each line were deduced from those data. Through comparison of experimental results and those listed in HITRAN and HITEMP2004 database, the discrepancies of most line intensities, air-broadening coefficients and their temperature exponents are less than 3%, 5% and 2% respectively. Those results show good consistency between the experimental data and that in HITRAN and HITEMP2004 database. The discrepancy in line intensities may be caused by the fitting of absorption spectra, the reading of thermocouple and pressure gage, uniformity of temperature in the heated cell, and uncertainty of the optical path. Those factors also cause the discrepancy in air-broadening coefficients and their temperature exponent. CO2 contained in air also introduces error in air-broadening coefficients and their temperature exponent beside those factors. Though we have deducted them in data-processing, the little change of CO2 in partial region also exists. Those results will be helpful to the measurement of CO2 concentration in combustion diagnosis in the future.
2009 Vol. 29 (06): 1463-1467 [Abstract] ( 364 ) PDF (991 KB)  ( 471 )
1468 Dual-Wavelength Mie Lidar Observations of Tropospheric Aerosols
CHI Ru-li1,2, WU De-cheng1, LIU Bo1, ZHOU Jun1
DOI: 10.3964/j.issn.1000-0593(2009)06-1468-05
A new dual-wavelength Mie lidar (DWL) is introduced. The DWL can be used to monitor the optical properties of tropospheric aerosol at 532 and 1 064 nm wavelength and their spatial and temporal variations, and to research aerosol size distribution with altitude. This lidar adopted four channels to receive the far and near range backscattering signal at 532 and 1 064 nm wavelength respectively. In order to enhance the capability of daytime measurement, the system employed a narrow band interference filter to separate the main backscattering signal of lidar return, including Mie backscattering signal and Rayleigh backscattering signal from the total backscattering signal including non-elastic scattering signal and solar spectrum, by cooperating with an iris to depress the majority of sky background noise. Overall structure and specifications of the lidar, as well as data processing method, were described. The lidar system has been operated in Hefei (117.16°E, 31.90°N). The profile of extinction coefficient of tropospheric aerosol and its temporal-spatial distribution were obtained. Angstrom exponent and optical depth of aerosol were also discussed. The observational results have shown that this lidar works well both during the day and at night and has the ability to measure the tropospheric aerosols and to manifest the temporal and spatial distributions of the aerosols with high precision.
2009 Vol. 29 (06): 1468-1472 [Abstract] ( 186 ) PDF (1232 KB)  ( 495 )
1473 Colon Adenoma Detection Using Kubelka-Munk Spectral Function of DNA and Protein Bands
WEI Hua-jiang1,GUO Zhou-yi1*,XIE Shu-sen2,HE Bo-hua3,LI Li-bo3,CHEN Xue-mei4,WU Guo-yong5, LU Jian-jun5
DOI: 10.3964/j.issn.1000-0593(2009)06-1473-05
Differential diagnosis of human colon adenoma was studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 590 to 1 064 nm pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r) and logarithmic Kubelka-Munk function log[f(r)] of the DNA absorption bands at 260 nm between normal and adenomatous colon epithelial tissues, and the differences were 218% (p<0.05) and 68.5% (p<0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r) and logarithmic Kubelka-Munk function log[f(r)] of the protein absorption bands at 280 nm between normal and adenomatous colon epithelial tissues, and the differences were 208%(p<0.05) and 59.0%(p<0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r) and logarithmic Kubelka-Munk function log[f(r)] of the β-carotene absorption bands at 480 nm between normal and adenomatous colon epithelial tissues, and the differences were 41.7%(p<0.05) and 32.9%(p<0.05) respectively. Obviously, pathological changes of colon epithelial tissues were induced so that there were significant changes in the contents of the DNA, protein and β-carotene of colon epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive optical biopsy of colon adenoma, and provides a useful reference.
2009 Vol. 29 (06): 1473-1477 [Abstract] ( 2677 ) PDF (608 KB)  ( 431 )
1478 MTF of Line-Array CCD on Detection Performance for Hyperspectral Imager
WANG Chun-hong1, 2, 3,XIANG Yang1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1478-04
As an image-spectrum merging technology,hyperspectral imaging has been used in battlefield reconnaissance rapidly.According to the definition of MTF based on contrast, the theoretical model of the MTF of line-array CCD was presented. The effect of the relative position of line-array CCD and input signal on MTF was analyzed. The results indicate that at the frequency-division of Nyquist frequency, the relative position has a strong effect on the MTF, which becomes much stronger with frequency increase, while at other frequency, the effect of the relative position on MTF depends on the percent error |ζ|, e.g. the bigger the value of |ζ|, the weaker the effect of the relative position on MTF. In the frequency range of |ζ|>0.1%, the effect of the relative position on MTF can be ignored. The above conclusions have directive significance in the design of MTF measure system of hyperspectral imager.
2009 Vol. 29 (06): 1478-1481 [Abstract] ( 1712 ) PDF (867 KB)  ( 428 )
1482 Synthesis of 1,2,5-Triphenyl-Pyrrole and Effect of Its Aggregation Degree on Photoluminescence Intensity
FENG Xiao1,TONG Bin1,SHEN Jin-bo1,ZHAO Wei1,ZHI Jun-ge2,SHI Jian-bing1,DONG Yu-ping1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1482-04
1,2,5-triphenylpyrrole (TPP) was firstly prepared by the Schulte-Reisch reaction of 1,4-diphenylbuta-1,3-diyne with aniline catalyzed by copper chloride. Compared to solution reaction in DMF as solvent, the bulk reaction modified in this paper not only increased the yield and reduced the reaction temperature, but also shortend the reaction time. The π—π stacking interaction and the restriction of intramolecular rotation are were involved at the same time when TPP was aggregated in the THF-water mixtures. When the water volume fraction was under 60%, the PL intensity of TPP was independent on the water fraction in THF-water mixture. When the water fraction was added to 70%, which induced the non-tight aggregation of TPP, the strong π—π stacking interaction toned the nonradiative deactivation process and led to quenching the fluorescence of TPP; if the water fraction was further increased to 80%, which induced the tight aggregation of TPP, the restriction of intramolecular rotation was, however, preponderant over π—π stacking interaction. Thus the nonradiative channel was blocked and the photoluminescence intensity of TPP was enhanced. The compact degree of aggregation was influenced by acetonitrile solvent due to the charge transfer interaction between TPP and acetonitrile. The aggregation-induced emission enhancement of TPP in THF-water mixture disappeared in acetonitrile-water mixture.
2009 Vol. 29 (06): 1482-1485 [Abstract] ( 1146 ) PDF (770 KB)  ( 364 )
1486 Effect of Ce3+ Implantation on Photoluminescence Intensity of Si Nanocrystals Embedded in Superlattices
DU Yu-fan, YI Li-xin*, WANG Shen-wei, WU Yang
DOI: 10.3964/j.issn.1000-0593(2009)06-1486-03
In the present paper, SiO/SiO2 superlattices samples were prepared on Si substrates by electron beam evaporation.The samples were annealed in nitrogen atmosphere at high temperature subsequently.And then,Ce3+ ions with a dose of 2.0×1014 and 2.0×1015 cm-2 respectively were implanted into these samples with formed Si nanocrystals. The photoluminescence (PL) spectra showed that the PL intensities of samples with Ce3+ implanting dropped sharply compared with the samples without Ce3+ implanting. The PL intensity increased gradually with increasing re-annealing temperature, but dropped again when the temperature exceeded 600 ℃. The PL intensity even could be higher than that of samples without Ce3+ implanting if only the dose of Ce3+ was 2.0×1014 cm-2. When the dose of Ce3+ was 2.0×1015 cm-2, the PL intensity couldn’t exceed that of samples without Ce3+ implanting even when the re-annealing temperature was 600 ℃. Further investigations showed that the varieties of the PL intensities were mainly dependent on the re-annealing temperature, which had the best point at 600 ℃, and the dose of Ce3+ had the right value. Furthermore, the experiment results proved that there was energy transfer from Ce3+ to Si nanocrystals in this kind of structure.
2009 Vol. 29 (06): 1486-1488 [Abstract] ( 578 ) PDF (616 KB)  ( 411 )
1489 Upconversion Luminescence Properties of ZBLAN∶Nd3+, Tm3+, Yb3+
YANG Zhi-ping,DU Hai-yan, SUN Jia-yue*,WANG Wei
DOI: 10.3964/j.issn.1000-0593(2009)06-1489-04
The ZBLAN∶Nd3+, Tm3+, Yb3+ upconversion materials were prepared by high-temperature solid method. The concentrations of Tm3+ and Yb3+ were 0.01% and 0.3% respectively. The concentration of Nd3+ changed in the range from 0.1% to 2%. The absorption spectrum of ZBLAN∶Nd3+, Tm3+, Yb3+ in all samples from 300 to 1 000 nm was measured at room temperature. The upconversion emission was observed when excited by 798 nm infrared light. The material samples emitted relatively strong multi-band (the red, blue and green color) visible light. Based on the experiment, the multi-band visible spectral lines were analyzed, and the energy level transition mechanism was given. The blue light results from the transition of 1G43H6 of Tm3+, the green light is from the transition of 2H7/24I9/2 of Nd3+, and the red light originates from the transition of 2H11/24I9/2 of Nd3+. The results show that the upconversion mechanism includes excited state absorption, energy transfer, cross relaxation and so on. The energy transfer processes between Nd3+, Tm3+ and Yb3+ ions both forward and backward prove to be the origin of upconversion emissions. The effect of rare earth doping concentration on the energy upconversion efficiency was analyzed, according to the different upconversion light emitting intensity from samples with different Tm3+ mol concentrations. The upconversion luminescence increased with the Nd3+ concentration and got its peak at 1.5%.
2009 Vol. 29 (06): 1489-1492 [Abstract] ( 472 ) PDF (718 KB)  ( 445 )
1493 Stray Light and Bandpass Correction in the Spectral Measurement for Light Emitting Diodes
SHEN Hai-ping1, PAN Jian-gen2, FENG Hua-jun1, XU Zhi-hai1
DOI: 10.3964/j.issn.1000-0593(2009)06-1493-05
The present paper introduces the stray light and bandpass correction methods for spectrometers. The line spread function of spectrometer is characterized by a He-Ne laser. Assuming that the spectrometer is a wavelength invariable system, the stray light distribution matrix is constructed by the derived line spread functions. The stray light correction matrix is then derived by matrix conversion from the stray light distribution matrix. The measured signals of the spectrometer are finally multiplied by the stray light correction matrix to correct the stray light errors. The bandpass functions of the spectrometer are characterized in three different wavelength ranges, respectively. And then three groups of bandpass correction coefficients are calculated accordingly. The calculation is divided into several steps. Given the measurement results at the target wavelength position and the ones on the neighbor bandwidths, the bandpass correction results are obtained by weight averaging of them. The bandpass correction coefficients are used as the weights. The two correction methods are applied to a multi-channel fast spectrometer to measure LEDs of different color. The results show that the stray light and the bandpass errors can be corrected effectively. The chromaticity coordinates of the LEDs are corrected by (-0.003, 0.007) for the maximum. Furthermore, the method introduced in this paper can reduce the application cost, simplify the calculation under a reasonable precision, and make the application of the correction easier.
2009 Vol. 29 (06): 1493-1497 [Abstract] ( 1711 ) PDF (1026 KB)  ( 407 )
1498 Study on Aconitum Kusnezoffii Reichb. and Its Processed Products by 2D-IR Correlation Spectroscopy
WANG Chao-lu1, WEN Jian-min1*, CHENG Ting1, JIANG Ke-wei1, SUN Su-qin2, TU Ya<sup>2
DOI: 10.3964/j.issn.1000-0593(2009)06-1498-04
2D-IR correlation spectroscopy and dynamic spectra tracked during mutative temperature process were used to do the research. The FTIR spectra of aconitum kusnezoffii Reichb. and its processed products are similar, the result by second derivative spectrum was analyzed, the absorption peaks at 1 745, 1 468 and 1 337 cm-1 shifted to the low wave number, while the absorption peak at 1 657 cm-1 shifted to the high wave number after being processed with acidophilus milk. Obvious differences are observed between 2D-IR spectra of them, active peaks of aconitum kusnezoffii Reichb. 1 650, 1 560 and 1 470 cm-1 were recorded in the region of 1 300-800 cm-1, and the strongest was at 1 560 cm-1. Automatic peaks and cross peaks presented a symmetric distribution of 3×3, and all were positive correlation. Automatic peaks of processed aconitum kusnezoffii Reichb. in the region were in four areas, one was 1 220 and 1 200 cm-1, the second was sharp peaks of 1 140 and 1 070 cm-1, the third was wide peaks in the region of 1 000-900 cm-1, and all the automatic peaks were positive correlation. Therefore, aconitum kusnezoffii Reichb. and its processed products can be identified intuitively by automatic and cross peaks of 2D-IR spectra, and the change laws of functional groups of them can be revealed. The method is rapid and exact, and can provide the means to analyze the structures’ change laws of aconitum kusnezoffii Reichb. after being processed.
2009 Vol. 29 (06): 1498-1501 [Abstract] ( 685 ) PDF (1381 KB)  ( 407 )
1502 Identification of Cistanche Deserticola from Boschniakla Rossica and Cynomorium Songaricum Using FTIR and Two-Dimensional Correlation IR Spectroscopy
CHEN Jun1,2, SUN Su-qin3, XU Rong1*, LIU You-gang4, YU Jing1, LIU Tong-ning5, LI Jian-qiang2
DOI: 10.3964/j.issn.1000-0593(2009)06-1502-06
In the present paper, Fourier transform infrared spectroscopy (FTIR) combined with two-dimensional correlation spectroscopy (2D-IR) was used for the identification of Cistanche deserticola from its adulterants, Boschniakla rossica and Cynomorium songaricum. The results showed that these IR spectra showed their different macro-fingerprint feathers: the charactersistic peaks for Cistanche deserticola were located at ~1 730 and 931 cm-1. While absorption peaks at ~1 510, 1 375 and 1 266 cm-1 were only found in Boschniakla rossica. And the strongest peak of Cynomorium songaricum was at 1 614 cm-1. Differences were more obvious in the second derivative IR spectra: the intensities of the four peaks of Cistanche deserticola at ~1 453, 1 336, 931, and 892 cm-1 were strong, among which the peak at ~931 cm-1 was sharp and the strongest in intensity. There was the strongest peak at ~1 509 cm-1 for Boschniakla rossica. In addition, the shape of peaks at ~1 633 and 1 161 cm-1 was wider and the intensities were stronger. While the shape of peak at ~1 682 cm-1 was sharp, and also the intensity of peak at 1 605 cm-1 was stronger. According to the features of the IR spectra of each kind, a quick and accurate method based on FTIR for the identification of Cistanche deserticola was established.
2009 Vol. 29 (06): 1502-1507 [Abstract] ( 2510 ) PDF (2219 KB)  ( 480 )
1508 Effects of Different Managements on Soil Humic Acid Structural Features in Chestnut Soil on Typical Leymus Chinensis Steppe, Inner Mongolia, China
LI Guang-jun,Lü Yi-zhong*,LI Bao-guo
DOI: 10.3964/j.issn.1000-0593(2009)06-1508-04
Grazing has a lot of effects on grassland soil properties. The objective of the present study is to investigate the effects of different managements on soil humic acids. Soil samples were collected from the surface soil of four adjacent plots (Ⅰ, Ⅱ, Ⅲ and Ⅳ) at a long-term experiment site of the Inner Mongolia Grassland Ecosystem Research Station (IMGERS), the Chinese Academy of Sciences. The structure features of humic acids were investigated by cross-polarization magic angle spinning 13C-nuclear magnetic resonance spectroscopy (CP/MAS13C-NMR), FTIR and elemental analysis. The results indicated that the humic acid extracted from the grazing plots were characterized by a higher degree of humification, including loss of polysaccharides, decrease in lignin content and increase in aromaticity. Compared with the humic substances from the grazing plots, the humic substances from fenced plots showed a lower degree of humification and were considerably more aliphatic in nature.
2009 Vol. 29 (06): 1508-1511 [Abstract] ( 2094 ) PDF (679 KB)  ( 392 )
1512 Research on Systematic Evolution of Ginkgo Biloba Based on Chemical Composition of Wood
GONG Qi-liang, HU Ai-hua, XING Shi-yan*, WANG Fang
DOI: 10.3964/j.issn.1000-0593(2009)06-1512-05
In the present article, the authors mensurated the infrared spectra of 22 conifer and broadleaf trees such as ginkgo biloba L., cycas revoluta thunb., Populus tomentosa Carr and so on using FTIR, analyzed the difference of a number of absorb peaks in fingerprint area, the characteristic absorb peak position of cellulose and lignin of these trees and their alternation regulations of relative intensity, then discussed the evolutional issue of ginkgo biloba. The results show that ginkgo biloba is different from cycas in the infrared spectra of wood but similar to the conifer trees, which illustrates the ginkgo biloba. is more evolutional than cycas in the timber’s chemical composition but with similar affiliation to conifer trees. The content of lignin in the ginkgo biloba wood is more than that in other conifer trees, which may be a original character of ginkgo biloba. Meanwhile, the ginkgo biloba has some syringyl lignins in addition to guaiacyl, and it has the evolutional tendency for broadleaf trees.
2009 Vol. 29 (06): 1512-1516 [Abstract] ( 2424 ) PDF (1107 KB)  ( 450 )
1517 Temperature Compensation for Calibration Model of Apple Fruit Soluble Solids Contents by Near Infrared Reflectance
WANG Jia-hua, PAN Lu, LI Peng-fei, HAN Dong-hai*
DOI: 10.3964/j.issn.1000-0593(2009)06-1517-04
The detection precision of soluble solids in apple fruit by near infrared reflectance (NIR) spectroscopy was affected by sample temperature. The NIR technique needs to be able to compensate for fruit temperature fluctuations. In the present study, it was observed that the sample temperature (2-42 ℃) affects the NIR spectrum in a nonlinear way. The temperature model was built with R2=0.985,RMSEC=1.88,and RMSEP=2.32. When no precautions are taken, the error in the SSC reading may be as large as 2.55%°Brix. Two techniques were found well suited to control the accuracy of the calibration models for soluble solids with respect to temperature fluctuations, such as temperature variable-eliminating calibration model and global robust calibration model to cover the temperature range. And an improved genetic algorithms (GAs) was used to implement an automated variables selection procedure for use in building multivariate calibration models based on partial least squares regression (PLS). The two compensation methods were found to perform well with RMSEP1=0.72/0.69 and RMSEP2=0.74/0.68, respectively. This work proved that the compensation techniques could emend the temperature effect for NIR spectra and improve the precision of models for apple SSC by NIR.
2009 Vol. 29 (06): 1517-1520 [Abstract] ( 2143 ) PDF (817 KB)  ( 455 )
1521 Study on Analysis of Copy Paper by Fourier Transform Infrared Spectroscopy
LI Ji-min1, 3, WANG Yan-ji2, WANG Jing-han3, YAO Li-juan3, ZHANG Biao3
DOI: 10.3964/j.issn.1000-0593(2009)06-1521-05
A new method of fast identification of copy papers by Fourier transform infrared spectroscopy (FTIR) was developed. The kinds of filler and the cellulosic degree of crystallinity were analyzed by FTIR, and the ageing curves of cellulosic paper were studied with heating and ultraviolet light. The cellulosic degree of crystallinity was showed by the ratio of absorbance at 1 429 cm-1 to that at 893 cm-1, the standard deviation of different brands of copy papers was 0.010 7-0.016 0, and the standard deviation of the same brands of copy papers was 0.014 8. The kinds of filler and the cellulosic degree of crystallinity were different in copy papers from different brands of different manufacturing plants, different brands of same manufacturing plants and different manufacturing times of the same brands from the same manufacturing plants, and the curves of ageing were different with heating and ultraviolet light. The results of fast identification of copy papers by FTIR are satisfactory.
2009 Vol. 29 (06): 1521-1525 [Abstract] ( 542 ) PDF (700 KB)  ( 391 )
1526 Study on Relationship between On-the-Go Near-Infrared Spectroscopy and Soil Texture
SHEN Zhang-quan1, Qi Jiaguo2, Huang Xuewen3, SHAN Ying-jie4, WANG Ke1
DOI: 10.3964/j.issn.1000-0593(2009)06-1526-05
Near infrared spectroscopy (NIRS) is a rapid, proximal-sensed method that has proven useful in quantifying soil constituents mainly in laboratory. However, very little is known about how NIRS performs in a field setting by newly developed on-the-go NIRS measurements. The objective of the present study was to evaluate the relationship between on-the-go field NIRS measurements and soil texture in a glacial till soil. It was found that NIRS band combination based on difference, normalized difference and ratio could apparently improve the coefficient of relationship between NIRS and soil texture, and this might be a new and effective analytical procedure for field NIRS measurements.
2009 Vol. 29 (06): 1526-1530 [Abstract] ( 1527 ) PDF (1795 KB)  ( 469 )
1531 Structural Characteristics of Humic Acids from a Long-Term Petroleum Contaminated Soil
ZHANG Jin-jing1, DOU Sen1, XIE Xiu-hong2, TANG Li-na1, SONG Xiang-yun3, QU Xiao-jing1
DOI: 10.3964/j.issn.1000-0593(2009)06-1531-05
Petroleum contamination in soil decreases with the increase in the distance of soil to the drilling well. Accordingly, an abandoned petroleum well which had been exploited for about twenty years in Songyuan city of Jilin Province, China, was selected to investigate the structural characteristics of soil humic acids (HAs) under different petroleum contamination levels. Surface (0-20 cm) soil samples were collected at 0.5, 1.5, 3.5, 5.5 and 7.5 m deep from well head, and the petroleum contents were respectively 153.3, 148.4, 129.2, 50.5 and 5.62 g·kg-1. HAs were extracted with 0.1 mol·L-1 NaOH and 0.1 mol·L-1 Na4P2O7 and were characterized with elemental analysis, Fourier transformed infrared (FTIR) spectroscopy and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR) spectroscopy. Results showed that the atomic C/H, O/C and (N+O)/C ratios of HAs increased from 0.74, 0.41 and 0.45 for 7.5 m to 0.80, 0.83 and 0.88 for 0.5 m, respectively. The relative intensity of the peaks assigned to aliphatic carbon (2 921, 2 851 and 1 454 cm-1) in the FTIR spectra gradually decreased with increasing contamination levels, while that of the peak assigned to aromatic C(1 600 cm-1 ) increased, and the calculated absorption intensity ratio of 2 921 to 1 600 cm-1(2 921/1 600) declined from 0.22 for 7.5 m to 0.11 for 0.5 m. The solid-state 13C NMR data suggested that the relative content of alkyl C(0-50 ppm ) decreased from 49.9% for 7.5m to 30.9% for 0.5 m, while that of O-alkyl C(50-110 ppm), aromatic C(110-160 ppm) and carboxyl C(160-190 ppm) increased respectively from 20.1%, 13.1% and 14.3% to 28.0%, 18.8% and 19.3%. These results showed substantial chemical, structural, and molecular differences among these HAs. The aliphaticity and hydrophobicity of HAs decreased while aromaticity and polarity increased with the increase in petroleum content. Namely, HAs tended to become aged in molecular structure. Therefore, it is imperative to renew and activate the aged HAs by adopting appropriate measures for the remediation of petroleum contaminated soil.
2009 Vol. 29 (06): 1531-1535 [Abstract] ( 584 ) PDF (828 KB)  ( 404 )
1536 Study on Vis/NIR Spectra Detecting System for Watermelons and Quality Predicting in Motion
TIAN Hai-qing1,2, YING Yi-bin1*, XU Hui-rong1, LU Hui-shan1, XIE Li-juan1
DOI: 10.3964/j.issn.1000-0593(2009)06-1536-05
To make Vis/NIR diffuse transmittance technique applied to quality prediction for watermelon in motion, the dynamic spectra detecting system was rebuilt. Spectra detecting experiments were conducted and the effects of noises caused by motion on spectra were analyzed. Then the least-square filtering method and Norris differential filtering method were adopted to eliminate the effects of noise on spectra smoothing, and statistical models between the spectra and soluble solids content were developed using partial least square method. The performance of different models was assessed in terms of correlation coefficients (r) of validation set of samples, root mean square errors of calibration (RMSEC) and root mean square errors of prediction (RMSEP). Calibration and prediction results indicated that Norris differential method was an effective method to smooth spectra and improve calibration and prediction results, especially, with r of 0.895, RMSEC of 0.549, and RMSEP of 0.760 for the calibration and prediction result of the first derivative spectra.
2009 Vol. 29 (06): 1536-1540 [Abstract] ( 502 ) PDF (1362 KB)  ( 413 )
1541 Identification of Varieties of Cashmere by Vis/NIR Spectroscopy Technology Based on PCA-SVM
WU Gui-fang1, 2, HE Yong1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1541-04
One mixed algorithm was presented to discriminate cashmere varieties with principal component analysis (PCA) and support vector machine (SVM). Cashmere fiber has such characteristics as threadlike, softness, glossiness and high tensile strength. The quality characters and economic value of each breed of cashmere are very different. In order to safeguard the consumer’s rights and guarantee the quality of cashmere product, quickly, efficiently and correctly identifying cashmere has significant meaning to the production and transaction of cashmere material. The present research adopts Vis/NIRS spectroscopy diffuse techniques to collect the spectral data of cashmere. The near infrared fingerprint of cashmere was acquired by principal component analysis (PCA), and support vector machine (SVM) methods were used to further identify the cashmere material. The result of PCA indicated that the score map made by the scores of PC1, PC2 and PC3 was used, and 10 principal components (PCs) were selected as the input of support vector machine (SVM) based on the reliabilities of PCs of 99.99%. One hundred cashmere samples were used for calibration and the remaining 75 cashmere samples were used for validation. A one-against-all multi-class SVM model was built, the capabilities of SVM with different kernel function were comparatively analyzed, and the result showed that SVM possessing with the Gaussian kernel function has the best identification capabilities with the accuracy of 100%. This research indicated that the data mining method of PCA-SVM has a good identification effect, and can work as a new method for rapid identification of cashmere material varieties.
2009 Vol. 29 (06): 1541-1544 [Abstract] ( 612 ) PDF (590 KB)  ( 418 )
1545 FTIR Analysis of Products Derived from Wood Liquefaction with 1-Octanol
ZOU Xian-wu1, YANG Zhi2, QIN Te-fu1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1545-04
Solvolysis is one of the important processes of biomass liquefaction. To produce superior quality liquid biofuel from biomass under mild conditions, it is essential to exploit novel reactive liquid solvent. Furthermore, the evaluation of liquefaction efficiency is carried out mainly by the means of analysis of the products derived from biomass liquefaction. In the present study, liquefaction of poplar wood powder in acidified 1-octanol was investigated with a stainless steel autoclave. Residue, heavy oil and light oil were separated from the liquefaction products by extraction with acetone and n-hexane successively. FTIR analysis was carried out on these liquefaction compositions to illuminate the liquefaction regularities and mechanisms of cellulose, hemicellulose and lignin of wood. The results showed that liquefaction oils were complex mixture containing hydroxide, carbonyl, methoxyl, aromatic and aether. Liquefactions of cellulose and hemicellulose were easier than that of lignin. Cellulose and hemicellulose were converted to light oil, however, lignin was mainly converted to heavy oil. At 150 ℃, lignin was depolymerized and degraded into micromolecular aromatic compounds, among which condensation reactions took place when reaction temperature increased.
2009 Vol. 29 (06): 1545-1548 [Abstract] ( 653 ) PDF (854 KB)  ( 398 )
1549 Application of Wavelet Packet Analysis in Estimating Soil Parameters Based on NIR Spectra
ZHENG Li-hua, LI Min-zan*, PAN Luan, SUN Jian-ying, TANG Ning
DOI: 10.3964/j.issn.1000-0593(2009)06-1549-04
Using the method of wavelet analysis, the NIR spectra of soil samples were decomposed and reconstructed, and higher precision PLS models were established to estimate soil parameter (TN, SOM). One hundred fifty soil samples were collected from a winter wheat field and the NIR spectra of all samples were measured. Firstly, experiment statistic features were analyzed aiming at all soil samples, and the system clustering was carried out for TN and SOM respectively. Then 50 new TN samples and their corresponding spectra, and 50 new SOM samples and their corresponding spectra were obtained. Secondly, the PLS models were established with these new samples based on their corresponding spectra. The models showed a certain amount of accuracy, but it was still not practical. Therefore, wavelet analysis of NIR spectra was tried. The wavelet packet decomposing by eight-level biorthogonal algorithm was carried out, and 256 nodes were gotten. The lowest approximation signal is corresponding to soil moisture and soil texture spectrum trend. The maximal detail signal is corresponding to the high-frequency turbulence caused by the soil particle size, precision of spectrometer, and other uncertainties. After reconstructing these two nodes and then removed from the original spectra, the characteristic spectra corresponding to each soil parameter were acquired. Finally, the PLS models were established for TN and SOM content respectively: for TN content, the calibration coefficient of the PLS model is 0.960, the validation coefficient is 0.920; and for SOM content, the calibration coefficient of the PLS model is 0.922, and the validation coefficient is 0.883. It was showed that the accuracy of each model was highly improved and the models were able to meet the needs of actual production. The research results conclude that wavelet analysis can eliminate or substantially reduce the factors outside the parameters. It can also remove the obstacles in establishing linear models of soil parameters, and it is feasible and potential method for the real-time estimation of soil parameters.
2009 Vol. 29 (06): 1549-1552 [Abstract] ( 1548 ) PDF (926 KB)  ( 455 )
1553 Application of Probabilistic Neural Networks Method to Gastric Endoscope Samples Diagnosis Based on FTIR Spectroscopy
LI Qing-bo1, LI Xiang1, ZHANG Guang-jun1*, XU Yi-zhuang2, WU Jin-guang2, SUN Xue-jun3
DOI: 10.3964/j.issn.1000-0593(2009)06-1553-05
In the present paper, probabilistic neural network method was applied to the classification of gastric endoscope samples based on FTIR spectroscopy for higher discrimination correctness than the conventional linear discriminant analysis algorithm. The probabilistic neural network (PNN) is a kind of radial basis network suitable for discriminant analysis. There are several advantages of PNN method: less time is needed to train the model, higher correctness could be achieved, global optimal solution could be obtained and so on. In this paper, PNN method was utilized to classify gastric endoscopic biopsies into healthy, gastritis, and malignancy. Firstly, principal component analysis was carried out for the pretreated sample spectra. Principal components analysis is a quantitatively rigorous method for achieving the simplification. The method generates a new set of variables, called principal components. Each principal component is a linear combination of the original variables. All the principal components are orthogonal to each other, so there is no redundant information. The principal components as a whole form an orthogonal basis for the space of the data. And then, the scores of principal components were selected as input to train the PNN model. Finally, PNN model was established. In this experiment, a total of 118 gastric endoscopic biopsies, including 35 cases of cancer, 64 cases of gastritis, and 19 healthy tissue samples, were obtained at the First Hospital of Xi’an Jiaotong University, China. Fifty nine samples were selected to establish the PNN classification model. The rest of the samples were used as the test set to valid the discriminant analysis model. The total discrimination correctness of normal, inflammation and gastric cancer achieved 81.4%.
2009 Vol. 29 (06): 1553-1557 [Abstract] ( 1668 ) PDF (846 KB)  ( 435 )
1558 Qualitative and Quantitative Analysis of Shuanghuanglian Fenzhenji by FTIR
YAN Shu1, XU Mao-ling1, TU Ya2, LI Hui-fen3*, SUN Su-qin2
DOI: 10.3964/j.issn.1000-0593(2009)06-1558-04
Qualitative and quantitative analysis of Shuanghuanglian fenzhenji was studied in the present paper by FTIR. The fingerprint characteristics of main components in the injections were assigned and can be used as the criterion in the qualitative quality control. Calibration models by PLS algorithm were built to get the quantitative information of baicalin and chlorogenic acid in the injection samples. The R2 of calibration models are both above 0.99 and the average relative deviations between predicted and actual value measured by HPLC are less than 4% for the both properties. The qualitative and quantitative analysis by FTIR is simple and rapid, so it may provide a new on-line approach to the quality control of main constituent in Shuanghuanglian fenzhenji and some other traditional Chinese medicines.
2009 Vol. 29 (06): 1558-1561 [Abstract] ( 2391 ) PDF (970 KB)  ( 435 )
1562 Study of Reference and Order Parameter of Raman Spectroscopy Research on Alkane Phase Transition
JIN Yuan-hao,CHEN Yi-ting,DU Wei-min*
DOI: 10.3964/j.issn.1000-0593(2009)06-1562-04
Raman spectroscopy was used to investigate the order-disorder phase transition of n-eicosane for real-time cooling run. At the phase transition temperature, the integrated intensity of the 1 300 cm-1 spectra range changes greatly, which requires further consideration of 1 300 cm-1 as a reference in the research on polymer and biomembrane using Raman spectroscopy. The experiment support was provided for doubt about order parameter based on 1 130 cm-1 that it did not refer to generally accepted interpretation of an order parameter and it proved that the order definition could just be used as a relative measure method for disorder.
2009 Vol. 29 (06): 1562-1565 [Abstract] ( 1122 ) PDF (671 KB)  ( 373 )
1566 Temperature Dependence of Additional Peaks Characteristics of Single Mode Silica Fiber Stimulated Raman Scattering
MEN Zhi-wei1, SUN Xiu-ping1, 2, GAO Shu-qin1,ZHANG Xi-he2,WANG Zhao-min2,LI Zuo-wei1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1566-04
Ten meter single mode silica fiber was used to study the temperature characteristics of stimulated Raman scattering (SRS), and additional peaks (double-humped structure) were observed at both sides of pump light and first-order Stokes light in the experiment. The peak intensity increased first, and then decreased as the temperature increased from 80 K to 295 K. The first-order Stokes double-humped wave peaks disappeared when the temperature was 295 K. The double-humped peaks phenomenon was caused by simulated four photon mixing (SFPM), according to stimulated four-photon mixing theoretical calculation. At the same time, the phenomenon that the frequency shift of first-order Stokes spectrum line in SRS increased from 706.9 to 712.9 cm-1 and its half width increased from 1.75 to 2.18 nm was theoretically explained, and the theoretical results are well consistent with experiments.
2009 Vol. 29 (06): 1566-1569 [Abstract] ( 2069 ) PDF (783 KB)  ( 447 )
1570 Discovery of Anatase in Atmospheric Inhalable Particles and Its Significance
ZHENG Nan, WANG He-jin*
DOI: 10.3964/j.issn.1000-0593(2009)06-1570-03
Laser Raman microprobe (LRM) is a reliable technique for phase identification to analyze the molecular composition and microstructure on 1 μm2 area of samples, and therefore, it is well-suited for identifying the mineral phases of single fine particles. In the present paper, we utilized LRM to identify the mineral phases of the single inhalable particles (PM10) from samples in Beijing City and compared the Raman microscopic spectra of samples with the standard spectra of mineral and inorganic material of Renishaw’s database. Then we confirmed, for the first time, that the mineral phase of Ti-rich particles in the environmental atmosphere is the anatase TiO2, whose Raman spectrum has a strong O—Ti—O band at 638 cm-1 and two medium O—Ti—O bands at 398 and 517 cm-1 respectively. Thus it ensures the existence of TiO2 particles in PM10. Anatase is an important photocatalyst which can speed up the heterogeneous reaction between mineral particles, especially the calcium carbonates, when carried by these particles. Furthermore, the crystal structure of anatase, relative humidity of environment and the surface pH value can significantly influence the photocatalysis of anatase in atmosphere.
2009 Vol. 29 (06): 1570-1572 [Abstract] ( 190 ) PDF (613 KB)  ( 374 )
1573 Evidence of Discontinuities in the Raman Spectra of Aqueous NaCl Solution at High Pressure
YANG Yu-ping1, ZHENG Hai-fei2*, SUN Qiang2
DOI: 10.3964/j.issn.1000-0593(2009)06-1573-04
In-situ Raman spectra measurement for aqueous NaCl solution was conducted at the temperature of 21 ℃ and the pressures of 50-1 100 MPa using a SiC anvil cell. It is shown that the decomposed bands of aqueous NaCl solution shift to lower wavenumber with increasing pressure initially and reaches the minimum at about 300 MPa, and increases at higher pressure up to about 800 MPa, then decreases again with increasing pressure. Similarly, the ratio of band-area and the width at half maximum of the decomposed bands of the solution exhibit discontinuities at about 300 and 800 MPa. This finding demonstrates that the structure of aqueous NaCl solution is discontinuous at high pressure and O—H…Cl- bonds change correspondingly, which suggests the existence of rearrangement and the appearance of more complicated configuration in the interior structrure of aqueous NaCl solution.
2009 Vol. 29 (06): 1573-1576 [Abstract] ( 1133 ) PDF (916 KB)  ( 383 )
1577 Raman Spectra Analysis of Nd∶YAG Single Crystal and Its Nano-Powder
SU Jing1, ZHANG Qing-li2, YIN Shao-tang2, SUN Dun-lu2, SHAO Shu-fang2
DOI: 10.3964/j.issn.1000-0593(2009)06-1577-04
In the present paper, the authors measured the Raman spectra of YAG/Nd∶YAG single crystal, Nd∶YAG precursor and the powder sintered at different temperatures. The bands of these Raman spectra were assigned and analyzed. The results show that there is a structure transformation process in the course of sintering Nd∶YAG precursor. The powder sintered at 700 ℃ was amorphous and it is of AlO4 tetrahedron structure. With the increase in sintering temperatures, the Raman spectra varied mainly in two respects. One is the decrease in FWHM with the increase in the bands intensity; the other is the bands shift. These should be due to the increase in the order degree of the interface component. Additionally, the difference in the lattice vibration modes between the powders sintered at 800 ℃ and the Nd∶YAG single crystal powder was caused by the contribution of the interface component.
2009 Vol. 29 (06): 1577-1580 [Abstract] ( 1645 ) PDF (920 KB)  ( 440 )
1581 Study of the Relationship between Apoptosis and Intracellular pH in Single Living Cells Using a Three-Channel Real-Time Fluorescence Imaging Method
LIN Dan-ying, LIU Xiao-chen, MA Wan-yun*
DOI: 10.3964/j.issn.1000-0593(2009)06-1581-05
Using a Dual-View wavelength splitter, a custom-made filter block and only a single intensified charge-coupled device (ICCD), a three-channel real-time fluorescence imaging method for single living cell research was established based on an ICCD fast fluorescence micro-imaging system. The relevant calibrating method for images was also developed to eliminate the influence introduced by spectral crosstalk. Double-labeled with two fluorescent indicators, Annexin V-FITC and SNARF-1, mouse thymocyte was treated with S-nitrosoglutathione (GSNO) and the relationship between their apoptosis and intracellular pH changes was studied in real-time at the single living cell level. The results not only showed the different regularities of intracellular pH changes between apoptosis induced by GSNO and spontaneous apoptosis, but also provided evidence for the application of the three-channel real-time fluorescence imaging method to bio-medical studies.
2009 Vol. 29 (06): 1581-1585 [Abstract] ( 1692 ) PDF (2377 KB)  ( 389 )
1586 Measurement of Near-UV Absorption Cross Sections of CS2
WANG Hai-tao1,HU Chang-jiang1,MU Yu-jing1*,Abdelwahid Mellouki2
DOI: 10.3964/j.issn.1000-0593(2009)06-1586-04
The UV-absorption cross sections of CS2 are reported. The absorption spectra were measured by using a diode array spectrometer over the wavelength range of 220-380 nm at room temperature (298±3)K. The maximum absorption cross section appeared around 315 nm with the value of σ(315 nm)=7.184×10-20 cm2·molecule-1. The measured data by this study were in good agreement with that reported in the literature, and used to estimate the photolysis of the CS2 in the atmosphere.
2009 Vol. 29 (06): 1586-1589 [Abstract] ( 574 ) PDF (508 KB)  ( 457 )
1590 Preparation of Nanocrystalline Goethite (α-FeOOH) by Gel-Network Precipitation Method and Spectral Properties
XIONG Hui-xin, ZHOU Li-xiang*
DOI: 10.3964/j.issn.1000-0593(2009)06-1590-05
Iron oxyhydroxides (FeOOH), as an environmental mineral material, can adsorb and coprecipitate the contamination from the medium. The ability of removing contamination is decided by the morphology and structural characteristic and the synthesis methods of the obtained mineral. In the present, the used synthesis methods of iron oxyhydroxides (FeOOH) include ferric iron hydrolyzation and ferrous chemical oxidation. But the products of iron oxyhydroxides prepared by these two chemical methods are easily agglomerated and form bigger particles. Thus, in the present study, a novel gel-network precipitation method was developed to synthesize the nanoparticles of goethite (α-FeOOH) as environmental mineral material. During formation of α-FeOOH nanoparticles by this method, FeCl3 acted as the reaction material and glutin played a role of the reaction medium, which prevents the presence of agglomeration of precipitate particles. So the obtained α-FeOOH nanoparticles had smaller size, no aggregation and basic monodispersity, compared with that prepared by the coprecipitation method. At the same time, we introduced the spectrum analysis measures, and studied the effect of different concentration of glutin and FeCl3 solution on the crystallizability and morphology of products. The structure and morphology of α-FeOOH nanocrystallites were determined by means of XRD, FTIR and SEM. The results of the spectrum analysis showed that the particle sizes and shapes and crystallizability of the obtained α-FeOOH precipitate products were highly related to the network structure of gelatin. And the goethite particles with better monodispersity, prepared by the optimum concentrations of glutin (12%) and FeCl3 solution (0.6 mol·L-1), had a short rod-type shape approximately 110 nm in length with an average diameter of about 35 nm.
2009 Vol. 29 (06): 1590-1594 [Abstract] ( 2416 ) PDF (1258 KB)  ( 408 )
1595 Study on the Modeling of Hyperspectral Polarized Reflection of Clove Lamina with Chlorophyll Content
HAN Yang1, ZHAO Yun-sheng1*, ZHANG Li-li2,Lü Yun-feng1
DOI: 10.3964/j.issn.1000-0593(2009)06-1595-04
In the present study, the authors detected clove laminas in different states with multi-angle hyperspectral polarized reflections and measured their chlorophyll content at the same time. The authors analyzed hyperspectral polarized reflections of clove laminas from various viewing zenith angles, incidence angles, the relative azimuth angles, polarized states and chlorophyll content. The authors calculated quantitatively clove laminas in different states with multi-angle hyperspectral polarized reflection by USB2000, bidirectional polarized reflectance and polarized equipment, and built the regression models of polarized information-chlorophyll content. The result indicated that when the polarized angle was 0°, the model of chlorophyll content with polarization reflectance was built as Y=4.506 4e-0.056 8X(R2=0.895 8); while as the polarized angle was 90°, the model of chlorophyll content with polarization reflectance was built as Y=145.79X-1.204 1(R2=0.479 8); when the incidence angle was 50°, the model of chlorophyll content with degree of polarization was built as Y=7 206.7X6-20 160X5+22 547X4-12 788X5+3 822.4X2-553.72X+30.429 (R2=0.646 4). The authors found that a significant functional relationship between the polarized information and chlorophyll content exists. The study provides a theoretical base for vegetation remote sensing.
2009 Vol. 29 (06): 1595-1598 [Abstract] ( 1133 ) PDF (937 KB)  ( 427 )
1599 Determination of DNA Using Eu-PPA as Fluorescence Probe by Time-Resolved Fluorescence
LIU Zhen, SUN Si-ling, LI Feng, XU Shu-kun*
DOI: 10.3964/j.issn.1000-0593(2009)06-1599-04
In the Tris-HCl buffer solution, europium ion combined with pipemidic acid (PPA) to form a Eu-PPA complex. The fluorescence intensity was dramatically enhanced when herring sperm DNA was added in the Eu-PPA system. Furthermore, the fluorescence intensity was increased linearly with the concentrations of added DNA within a proper range. Based on this, a simple new method for the determination of herring sperm DNA was developed. Time-resolved fluorescence excitation and emission spectra and the fluorescence lifetime of the system were studied in detail and compared with that from conventional fluorescence method. The experimental results indicated that the time-resolved fluorescence method was superior over the conventional fluorescence method. The reaction conditions, measurement parameters and the adding order of reactants were optimized. The best concentration of both europium ion standard solution and PPA standard solution was 1.00×10-5 mol·L-1 in the Tris-HCl buffer solution of 0.005 mol·L-1 with the optimal pH value of 7.2. A detection limit (3 s) of 0.03 mg·L-1 was obtained with a RSD of 0.3% (4.0 mg·L-1, n=11). The linear relationship between ΔI=89.58(mg·L-1)+0.920 5 and the regression factor of 0.999 6 was obtained in the range of 0.1-6.0 mg·L-1. This method was applied to the determination of DNA in synthetic samples. The results and recoveries of spiked standard solution in the sample were satisfied.
2009 Vol. 29 (06): 1599-1602 [Abstract] ( 1098 ) PDF (811 KB)  ( 403 )
1603 Spectroscopic Investigation on the Interaction of Protocatechuic Acid and Veratric Acid with Biomacromolecules
LONG Mei1,2, XIE Meng-xia1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1603-04
Protocatechuic acid (P) and veratric acid (V) are phenolic acidic compounds and have a wide biological and pharmaceutical activities, and their interaction with biomacromolecule has been a hot topic. The interaction mechanism of P and V with fsDNA was investigated by fluorescence and UV absorption spectroscopic methods. The UV results showed that P and V have three strong absorption bands at 190-230 nm (K band), 230-270 nm (B band) and 270-310 nm (R band) respectively. When the excitation wavelength was 280 nm, the fluorescence emission bands of P and V were at 338 and 334 nm, respectively, while the fluorescence emission band of DNA was very weak and had little influence on those of the P and V. The fluorescence intensities of the P and V were strongly quenched after interacting with fsDNA, and their Stern-Volmer quenching rate constants were 1.03×1012 and 0.61×1012 L·mol-1·s-1,respectively. It was illustrated that the fluorescence quenching was mainly static and the complex was formed between the drug and fsDNA. When the concentration of DNA was high, their Stern-Volmer curves were not linear, and it was indicated that the quenching mechanism was complex and may contain dynamic quenching process. Their binding constants were calculated based on the static fluorescence quenching, with KfsDNA/P=6.22×106 L·mol-1 and KfsDNA/V=1.57×104 L·mol-1. The investigation showed that the molecular ratio of V-fsDNA was 1∶1, while that of P-fsDNA was 1∶2. It was demonstrated that the protocatechuic acid can bind with two bases of fsDNA, which was related to the two hydroxyl groups on the drug molecule. The results showed that the structure of P and V greatly influenced their binding mode with DNA molecules.
2009 Vol. 29 (06): 1603-1606 [Abstract] ( 703 ) PDF (975 KB)  ( 435 )
1607 SPAD Prediction of Leave Based on Reflection Spectroscopy
YANG Hai-qing1,2, YAO Jian-song3,HE Yong1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1607-04
Handheld SPAD meter is often used to measure chlorophyll content of plant and nitrogen level for some species. For plant production automation, however, it loses its popularity due to its point-by-point checking. The authors need to monitor the growing conditions of plant remotely, instantly and nondestructively. In the test, we examined optical fiber reflection spectroscopy used to measure chlorophyll content of some plant leaves, or for their SPAD prediction. The authors picked 120 leaves randomly from our campus ground or trees, among which 70 samples were chosen as calibration set and others as verification set. Each sample was water-cleaned and air-dried. To locate each measuring point precisely when using SPAD meter and spectrometer, the authors drew a circle with a diameter of 10 mm on each leave to be measured. By comparing the spectral curves of various leaves, the authors found that the spectral band between 650-750 nm was significant for SPAD modeling since this range of spectral data of leaves with the same SPAD reading was close to each other. It was showed that leave color was an unnecessary factor for SPAD prediction by reflection spectroscopy. Besides, the authors discovered that LED’s narrow spectral range used by SPAD meter should be concerned because optical fiber spectrometer has much more wide spectral range. Based on this awareness, the authors designed an adjustment factor of light to linearly rebuild spectrometer’s reflective intensity so that it reached zero outside the band 650-750 nm. Moreover, leave thickness was another influential factor for SPAD prediction since the light of SPAD meter goes through the leave while the reflective spectrometer does not. First, an equation for SPAD prediction was built with uncertain parameters. Then, a standard genetic algorithm was designed with Visual Basic 6.0 for parameter optimization. As a result, the optimal reflection band was narrowed within 683.24-733.91 nm. The result showed that leave thickness strongly affects the precision of SPAD prediction. Through the modification of leave thickness, the regression coefficient (R2) of calibration set and verification set reached 0.865 8 and 0.916 1 respectively. The test showed that optical fiber reflection spectroscopy is useful for SPAD prediction and can be used to develop remote SPAD sensor.
2009 Vol. 29 (06): 1607-1610 [Abstract] ( 2755 ) PDF (961 KB)  ( 447 )
1611 Advance in Nondestructive Detection of Fruit Internal Quality Based on Hyperspectral Imaging
MA Ben-xue1, 2, YING Yi-bin1*, RAO Xiu-qin1, GUI Jiang-sheng1
DOI: 10.3964/j.issn.1000-0593(2009)06-1611-05
The present paper reviews the development in the field of hyperspectral imaging technology for nondestructive detection of fruit internal quality in recent years up to the year 2007. With the increasing maturity of hyperspectral imaging technology, decline of cost for its hardware and software, and improvement in hyperspectral image data processing algorithms, hyperspectral imaging technology for fruit quality nondestructive detection has become a hot research topic. In order to track the latest research developments at home and abroad, the fruit internal quality (maturity, firmness, soluble solid content, water content) detection with hyperspectral imaging was reviewed, which would provide reference for Chinese researchers.
2009 Vol. 29 (06): 1611-1615 [Abstract] ( 1095 ) PDF (889 KB)  ( 510 )
1616 Review of Digital Ground Object Spectral Library
ZHOU Xiao-hu1, 2,ZHOU Ding-wu1, 3
DOI: 10.3964/j.issn.1000-0593(2009)06-1616-07
A higher spectral resolution is the main direction of developing remote sensing technology, and it is quite important to set up the digital ground object reflectance spectral database library, one of fundamental research fields in remote sensing application. Remote sensing application has been increasingly relying on ground object spectral characteristics, and quantitative analysis has been developed to a new stage. The present article summarized and systematically introduced the research status quo and development trend of digital ground object reflectance spectral libraries at home and in the world in recent years. Introducing the spectral libraries has been established, including desertification spectral database library, plants spectral database library, geological spectral database library, soil spectral database library, minerals spectral database library, cloud spectral database library, snow spectral database library, the atmosphere spectral database library, rocks spectral database library, water spectral database library, meteorites spectral database library, moon rock spectral database library, and man-made materials spectral database library, mixture spectral database library, volatile compounds spectral database library, and liquids spectral database library. In the process of establishing spectral database libraries, there have been some problems, such as the lack of uniform national spectral database standard and uniform standards for the ground object features as well as the comparability between different databases. In addition, data sharing mechanism can not be carried out, etc. This article also put forward some suggestions on those problems.
2009 Vol. 29 (06): 1616-1622 [Abstract] ( 2141 ) PDF (859 KB)  ( 428 )
1623 Fabrication and Photocatalytic Activity of Pt-Inserted Titania Nanotubes
LI Hai-long1,LUO Wu-lin1,TIAN Wen-yu1,CHEN Tao1,LI Chun1,SUN Mao1,ZHU Di1, LIU Ran-ran1, ZHAO Yu-liang2, LIU Chun-li1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1623-04
Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticals in NaOH solution at 110 ℃ for 24 hours. After drying in aceton for 36 h, the TNTs were under vacuum drying for 24 h at room temperature. The Pt-inserted titania nanotubes (Pt/TNTs) were obtained by filling H2PtCl6 ethanol solution into the TNTs after vacuum drying. The characterizations of the as-synthesized samples were confirmed by TEM, XRD, and UV-Vis. The photocatalytic activity of the Pt/TNTs was investigated by photo-induced decomposition of methyl orange(MO)under the main 365 nm UV-light. In order to comparison, the photocatalytic activity of both the rutile-phase TiO2 nanoparticles and pure TNTs were also investigated at the same time under the same experimental conditions. The TEM images show that the TNTs are hollow, a few hundred nanometers long, and the inner/outer diameter is about 6/10 nm. The crystal structure of TNTs is H2Ti2O5·H2O with a little Na. Both the shape and the crystalline of the TNTs are not changed after the modification. The oval or round Pt0 nanoparticals, about 3 nm in diameter, are found only in the nanotubes. Pt/TNTs exhibit enhanced absorption at the visible range in the UV-Vis spectra and its start absorption band edge(λ0≈457 nm)is obviously redshifted compared to the rutile-phase TiO2 nanoparticals and pure TNTs. The Pt nanoparticles are found to significantly enhance the photocatalytic activity of TNTs. Pt/TNTs are demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both the rutile-phase TiO2 nanoparticals and pure TNTs. After irradiation for 60 min, the photocatalysis decomposition rate of MO in rutile-phase TiO2 nanoparticals, TNTs and Pt/TNTs are 46.8%,57.2% and 84.6% respectively.
2009 Vol. 29 (06): 1623-1626 [Abstract] ( 548 ) PDF (819 KB)  ( 415 )
1627 Detecting Land Use Change Using PCA-Enhancement and Multi-Source Classifier from SPOT Images
DENG Jin-song1, LI Jun2, WANG Ke1
DOI: 10.3964/j.issn.1000-0593(2009)06-1627-05
Concomitant with the rapid global urbanization process, land use change detection has been the focus and “hot spot” of global change research all the time. In the present study, the rigorous orthorectification was first applied to the SPOT-5 data to guarantee precise geometric correction and image registration. Afterwards, a methodology integrating PCA-enhancement and multi-source classifier was adopted to detect the land use changes in urban area. The results show that the first three PCs derived from multi-temporal-PCA contain most of the spectral information among which unchanged land use is highlighted in PC1 and PC2, and changed land use is mainly enhanced in PC3. The following multi-source classifier integrating unsupervised classifier (ISODATA) and supervised classifier (Maximum Likelihood) accurately extracts all the information. The findings from accuracy assessment demonstrate that the overall accuracy for the proposed method reaches 92.58%, KAPPA coefficient is 0.92, and proving figures are also produced for the user’s and producer’s accuracies. It was further found that the proposed method yielded better accuracy than that of traditional post-classification comparison approach.
2009 Vol. 29 (06): 1627-1631 [Abstract] ( 1470 ) PDF (1381 KB)  ( 354 )
1632 Time Resolved UV-Vis Absorption Spectra of Quercetin Reacting with Various Concentrations of Sodium Hydroxide
YANG Li-jun1, LI Ping1*, GAO Yan-jun1, LI Hui-feng1, WU Da-cheng2, LI Rui-xia2
DOI: 10.3964/j.issn.1000-0593(2009)06-1632-04
A real time investigation of chemical reaction process of quercetin with various concentrations of sodium hydroxide was performed by using an intensified spectroscopic detector ICCD. The time resolved UV-Vis absorption spectra of 5×10-5 mol·L-1 quercetin respectively reacting with sodium hydroxide at concentrations of 2, 0.2, 0.1, 0.04 and 0.02 mol·L-1 were acquired. A total of 200 spectra with the same exposure time of 0.1 ms for each spectrum but different time interval between two consecutive spectra were recorded for each reaction. The first 50 spectra have the time interval of 20 ms, the next 50 have 1 s, and the last 100 have 2 s. Results indicate that quercetin reacted with sodium hydroxide easily and there was an intermediate product formed during the reaction, with different concentrations of reactants, the changes of absorption bands were the same, but the moments at which the changes happened were different and the total reaction time was various from 1 s to 100 s. Spectra recorded showed the disappearing process of the typical bands centered at 254 and 374 nm of pure quercetin, the growing and disappearing processes of a new band centered at 427 nm of the intermediate product, and the growing process of the new band centered at 314 nm of the final product obviously. No other transient spectroscopic data are currently available on the reaction of quercrtin with sodium hydroxide, the results obtained in the present work provide useful experimental data for the study of the microscopic process of the reaction.
2009 Vol. 29 (06): 1632-1635 [Abstract] ( 1562 ) PDF (935 KB)  ( 431 )
1636 Application of Hyperspectral Remote Sensing in Research on Ecological Boundary in North Farming-Pasturing Transition in China
WANG Hong-mei1, 2, WANG Kun1*, XIE Ying-zhong2
DOI: 10.3964/j.issn.1000-0593(2009)06-1636-04
Studies of ecological boundaries are important and have become a rapidly evolving part of contemporary ecology. The ecotones are dynamic and play several functional roles in ecosystem dynamics, and the changes in their locations can be used as an indicator of environment changes, and for these reasons, ecotones have recently become a focus of investigation of landscape ecology and global climate change. As the interest in ecotone increases, there is an increased need for formal techniques to detect it. Hence, to better study and understand the functional roles and dynamics of ecotones in ecosystem, we need quantitative methods to characterize them. In the semi-arid region of northern China, there exists a farming-pasturing transition resulting from grassland reclamation and deforestation. With the fragmentation of grassland landscape, the structure and function of the grassland ecosystem are changing. Given this perspective; new-image processing approaches are needed to focus on transition themselves. Hyperspectral remote sensing data, compared with wide-band remote sensing data, has the advantage of high spectral resolution. Hyperspectral remote sensing can be used to visualize transitional zones and to detect ecotone based on surface properties (e.g. vegetation, soil type, and soil moisture etc). In this paper, the methods of hyperspectral remote sensing information processing, spectral analysis and its application in detecting the vegetation classifications, vegetation growth state, estimating the canopy biochemical characteristics,soil moisture, soil organic matter etc are reviewed in detail. Finally the paper involves further application of hyperspectral remote sensing information in research on local climate in ecological boundary in north farming-pasturing transition in China.
2009 Vol. 29 (06): 1636-1639 [Abstract] ( 1187 ) PDF (556 KB)  ( 405 )
1640 A New Immuno-Nanosliver Resonance Scattering Spectral Probe for Assay of IgG
WEI Xiao-ling1, ZHANG Yu-lan2, JIANG Zhi-liang2*
DOI: 10.3964/j.issn.1000-0593(2009)06-1640-03
Using tri-sodium citrate as reducer, stable silver nanoparticles the size of about 20 nm were prepared by the microwave high pressure procedure with simplicity and rapidity. At pH 9.0, sliver nanoparticle was used to label goat anti-human IgG (GIgG) to obtain an immuno-nanosilver resonance scattering spectral probe (AgGIgG) for IgG. In pH 6.0 buffer solution and in the presence of polythylene glycol (PEG) and KCl, the immune reaction of IgG with AgGIgG took place, the silver nanoparticles released from AgGIgG produced aggregations, and the resonance scattering intensity at 485 nm (I485 nm) was enhanced greatly. The influence factors such as pH value, buffer solution volume, concentration of AgGIgG, KCl, PEG-4000,PEG-6000,PEG-10000 and PEG-20000, incubation temperature and time were considered, respectively. Under the conditions of 0.40 mL of pH 6.0 phosphate buffer solution, 1.20 mL of 9.8 μg·mL-1 AgGIgG,0.20 mL of 20% PEG-6000, 0.50 mL of 10% KCl,and ultrasonic irradiation for 25 min at room temperature, the increased intensity ΔI485 nm was proportional to the IgG concentration (cIgG) from 0.004 to 0.48 μg·mL-1, with a detection limit of 2.4 ng·mL-1. The regress equation was ΔI485 nm=76.8cIgG+4.7. The effect of foreign substances such as 20μg·mL-1 Ni2+, Fe2+, Pb2+ and BSA,60 μg·mL-1 Cu2+, Ca2+ and HSA,60 μg·mL-1 Mg2+ and Mn2+, 320 μg·mL-1 Zn2+, glucose and urea on the ΔI485 nm was examined, respectively. Results showed that there was no interference. This assay showed high sensitivity and good selectivity for quantitative determination of IgG in human serum with satisfactory results. The analytical results were in agreement with that of the reference results.
2009 Vol. 29 (06): 1640-1642 [Abstract] ( 1269 ) PDF (464 KB)  ( 386 )
1643 Determination of the Daily Changes Curve of Nitrogen Oxides in the Atmosphere by Digital Imaging Colorimetry Method
YANG Chuan-xiao, SUN Xiang-ying*, LIU Bin
DOI: 10.3964/j.issn.1000-0593(2009)06-1643-04
From the digital images of the red complex which resulted in the interaction of nitrite with N-(1-naphthyl) ethylenediamine dihydrochloride and P-Aminobenzene sulfonic acid, it could be seen that the solution colors obviously increased with increasing the concentration of nitrite ion. The JPEG format of the digital images was transformed into gray-scale format by origin7.0 software, and the gray values were measured with scion image software. It could be seen that the gray values of the digital image obviously increased with increasing the concentration of nitrite ion, too. Thus a novel digital imaging colorimetric (DIC) method to determine nitrogen oxides (NOx) contents in air was developed. Based on the red, green and blue (RGB) tricolor theory, the principle of the digital imaging colorimetric method and the influential factors on digital imaging were discussed. The present method was successfully applied to the determination of the daily changes curve of nitrogen oxides in the atmosphere and NO-2 in synthetic samples with the recovery of 97.3%-104.0%, and the relative standard deviation (RSD) was less than 5.0%. The results of the determination were consistent with those obtained by spectrophotometric method.
2009 Vol. 29 (06): 1643-1646 [Abstract] ( 1064 ) PDF (912 KB)  ( 353 )
1647 Difference Expressed Protein Study on Unstable Angina Blood-Stasis Syndrome by Fluorescence Labelling Method
ZHAO Hui-hui1,HOU Na2, WANG Wei2*
DOI: 10.3964/j.issn.1000-0593(2009)06-1647-04
Fluorescence labelling method was used seeking differentially expressed plasma proteins of unstable angina blood-stasis syndrome. Three fluorescence labelling dyes (Cy2, Cy3 and Cy5) were used on two classes of species (plasma of 12 patients with unstable angina blood-stasis syndrome and 12 healthy volunteers) Two dimensional gel electrophoresis was carried out, and three different fluorescence scans were performed. By analyzing the graphs and mass spectrometry, the differentially expressed plasma proteins of unstable angina were obtained. Blood-stasis syndrome. Results show that fibrinogen β chain, fibrinogen γ chain, α1-antitrypsin, haptoglobin β chain and haptoglobin α2 chain were significantly highly expressed in the plasma of unstable angina blood-stasis syndrome patient,while ApoA-Ⅳ, ApoA-Ⅰ and transthyretin were decreased in the plasma of unstable angina blood-stasis syndrome patient. These identified proteins could be divided into two categories according to their functions: (1) Acute phase reactive protein; (2) Apolipoprotein. In conclusion, fibrinogen β chain, fibrinogen γ chain, α1-antitrypsin, transthyretinc, haptoglobin β chain, ApoA-Ⅳ, ApoA-Ⅰ and haptoglobin α2 chain are differentially expressed in the patients with unstable angina blood-stasis syndrome and control group, some differentially expressed proteins were correlated with inflammatory reaction or lipid metabolic disorder, and these proteins could provide clues to the study and discovery of new protein targets for antianginal drugs. The fluorescence labelling method is suitable for discovery of differentially expressed proteins.
2009 Vol. 29 (06): 1647-1650 [Abstract] ( 237 ) PDF (846 KB)  ( 452 )
1651 Research on the Autofluorescence Spectroscopy of Heart Tissues
XU Zheng-hong1, 2, ZHANG Zhen-xi1*, WANG Jing1, LI Zheng1, LIU Xue-liang1
DOI: 10.3964/j.issn.1000-0593(2009)06-1651-05
The present study investigated the three-dimensional spectra and emission spectra of the autofluorescence of rabbit hearts. The results suggested that the three-dimensional spectra of the iced atria and ventricle were observed more evidently different from that of the fresh tissue compared to the main artery, which indicated that the amount of flavins and NADHs changed. Also, the atria, ventricle and main artery have different specific excitation spectra at the wavelength of 340 nm. The main fluorescence peaks were of NADH (at about 460 nm), collagen and elastin (at about 290-400 nm).The Gauss spectra of atria and ventricle were different in the peak value, relative intensity and half width. So the ratios of fluorescence intensities of peaks may be used to distinguish different heart tissues. Furthermore, a phenomenon was firstly uncovered that the autofluorescence intensity of NADH in ventricle decays with the time of death and it could be a useful method for the estimation of postmortem interval.
2009 Vol. 29 (06): 1651-1655 [Abstract] ( 2165 ) PDF (1119 KB)  ( 368 )
1656 Enteromorpha Prolifera Underwater Spectral Research Based on Simulation of Radiation Transmission
ZHAO Wen-jing1, ZHANG Jie1, 2, CUI Ting-wei1*, HAO Yan-ling1, SUN Ling3, 4
DOI: 10.3964/j.issn.1000-0593(2009)06-1656-05
The accumulation of Enteromorpha prolifera in huge amount in the Yellow sea in June, 2008 draws the attention from all over the world. It is an urgent requirement to monitor the wide range of Enteromorpha prolifera distribution by remote sensing. As to the Enteromorpha prolifera floating on the sea surface, effective monitoring by optical remote sensing has been basically achieved. As far as the underwater suspended Enteromorpha prolifera is concerned, the present paper carried out the radiative transfer simulation research on the above water spectral response, its variation with the suspending depth, the water turbidity and environmental conditions. It was found that with the increase in Enteromorpha prolifera suspending depth and water turbidity as well as the decrease in the thickness of Enteromorpha prolifera, the Enteromorpha prolifera information contained in the surface spectra would decrease. The influence of environmental factors such as water-gas interface roughness, cloud cover extent and sun zenith angle on the underwater suspended Enteromorpha prolifera spectra can be ignored. The maximum Enteromorpha prolifera depth that can cause surface spectrum changes is about 30 m in clean water and about 1 m in turbidity water.
2009 Vol. 29 (06): 1656-1660 [Abstract] ( 351 ) PDF (917 KB)  ( 439 )
1661 Degradation of Organic Contaminant in Landfill Leachate by Photo-Fenton Process
ZHENG Huai-li1*, PAN Yun-xia2, LI Dan-dan1, WU You-quan1
DOI: 10.3964/j.issn.1000-0593(2009)06-1661-04
In the present work, the treatment of landfill leachate was studied by photo-Fenton process. All photocatalytic experiments were carried out under similar conditions on July or August sunny days between 12 a.m. and 14 p.m. in Chongqing based on the change in solar light intensity with time. The effect of operating conditions such as Fe/H2O2, pH value and Fenton’s reagent dosage on color removal and UV254 was investigated. The UV-Vis absorption spectra of 1.00×103 mg·L-1 landfill leachate were considered before and after photo-Fenton experiment. The experiment result indicated that photo-Fenton process can effectively remove color. The oxidation of organic materials in the leachate was pH dependent and the optimal pH was 2.5. The favorable Fe2+ to H2O2 molar ratio was 1/95. The optimal conditions in this research were Fe2+ concentration of 5.00 mmol·L-1 and H2O2 concentration of 5.70×102 mmol·L-1. Meanwhile, the analysis of reaction kinesics was carried out in the research. Second-order kinetic was observed for the degradation of landfill leachate, and the rate equation of photo-Fenton process was -d/dt=-4.34[c]1.92. The result of UV-Vis spectra of landfill leachate showed that photo-Fenton process is an effective method for removal of organic compounds.
2009 Vol. 29 (06): 1661-1664 [Abstract] ( 1708 ) PDF (1253 KB)  ( 397 )
1665 Spectroscopic Investigation of the Poly[(Silylene)acetylene silanes]
YAN Mei1, CHEN Xin1, TAN Yong-xia2, ZHANG Zhi-jie2, XIE Ze-min2
DOI: 10.3964/j.issn.1000-0593(2009)06-1665-03
In the present paper, a series of novel conjugated polymers, poly[(silylene)acetylene silanes] with different structure, were prepared, and the luminescence performance of the poly[(silylene)acetylene silanes] with different substituents were investigated by the fluorescence and UV absorption spectroscopic approaches. The effect of different substituents and the number of acetylene in the main chain on the luminescence was discussed in depth. The result showed that these polymers have moderate absorbance in the range from 219 to 260 nm. The red shift was showed for the maximum absorbance wavelength following the increase in the number of the acetylene and the degree of the conjugation in the main chain. There was insignificant difference in the maximum absorbance wavelength of the polymers with dimethy and diphenyl. In short, the influence of the substituents is insignificant. However, the remarkable effect was induced by the conjugated structure in the main chain. The conjugated polymers with different structure in the main chain have moderate fluorescence and emission quantum yields. The authors studied the influence of the polymers’ structure on the luminescence performance. As a result, the influence of the substituents is insignificant for emission spectra. The influence of the conjugated groups in the main chain of the polymers is remarkable. The maximum emission wavelength of the polymers showed an evident shift to red range with the enhancement of the conjugated extent. These polymers had good thermal properties for the special structures. So they have potential applications for emission materials with good thermal stability.
2009 Vol. 29 (06): 1665-1667 [Abstract] ( 1642 ) PDF (524 KB)  ( 439 )
1668 Analysis of the Extraction of Red Pellicle of Walnut (Juglans regia L. ) by Ultraviolet-Visible Spectra and HPLC-ESI-MSn
WANG Ke-jian1, 2, HAO Yan-bin2, QI Jian-xun2, HU Xiao-song1*
DOI: 10.3964/j.issn.1000-0593(2009)06-1668-04
The extraction of the red pellicle of walnut (Juglans regia L. ) was analyzed by UV-visible spectra and HPLC-ESI-MSn (high-performance-liquid-chromatography coupled with electrospray ionization mass spectrometry). The extraction in ethanol-HCl showed two absorption peaks at 560 and 591 nm respectively in the UV-Vis spectrum; after purified by lead acetate and thin-layer-chromatography, the extraction in ethanol-HCl showed 4 absorption peaks at 340, 370, 552 and 585 nm respectively. These results testified that the anthocyanin was in the extraction. Six molecular ion peaks (m/z) occurred on MS: 301, 481, 633, 783, 785 and 950, which was identified as ellagic acid, Hexahydroxydiphenoyl(HHDP)-glucose, Galloyl-HHDP-glucose, Di-HHDP-glucose, Di-Galloyl-HHDP-glucose, and HHDP-Valoneoyl-glucose respectively.
2009 Vol. 29 (06): 1668-1671 [Abstract] ( 2557 ) PDF (906 KB)  ( 397 )
1672 LED Illuminant-Based Detection of Trace NO2 Gases
SUN Xiu-ping1,2,ZHANG Xi-he1,WANG Da-cheng1,FENG Ke-cheng1,NA Yan-xiang1,LIU Jian-guo3,LIU Wen-qing3
DOI: 10.3964/j.issn.1000-0593(2009)06-1672-03
Light-emitting diode was used as illuminant in the present paper. The light-emitting diode was chosen according to the high absorption in the range of absorption spectrum of NO2. The pollutant concentration can be calculated by measuring the absorption spectrum, and fitting the experimental absorption spectrum and normal absorption spectrum by means of least square fitting method. The method of measuring nitrogen dioxide concentration making use of absorption spectra was studied, the basic principle was analyzed, the process of data analysis was studied including the fitting of experimental spectrum and standard spectrum, wiping off the slow change, using least-square fitting in reverse calculating of concentration etc. The detecting precision was improved by the method of absorption spectrum. In this experiment the light emitting diode was used as illuminant, which made the detecting become not only convenient but also fast, and online real time supervising can be realized. Taking advantage of the characteristic that NO2 has strong absorption in the range of 300-500nm, the NO2 concentration of sample was measured.
2009 Vol. 29 (06): 1672-1674 [Abstract] ( 499 ) PDF (735 KB)  ( 465 )
1675 Determination of As in Industrial Wastewater by Laser-Induced Breakdown Spectroscopy
LIN Zhao-xiang1, CHANG Liang1,LI Jie2, LIU Lin-mei1
DOI: 10.3964/j.issn.1000-0593(2009)06-1675-03
The wastewater from industrial smelting process contains heavy metals such as arsenic (As) that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to control the pollution at the source and achieve a real-time and online monitoring. The laser-induced breakdown spectroscopy (LIBS) is a new elemental analysis technique, and has the advantage of rapid detection. An LIBS setup has been established. The Nd∶YAG laser beam is focused onto the sample, then the plasmas are produced. The emission spectra of plasmas are dispersed by an Echelle spectrograph and detected by an intensified charge-coupled device (ICCD). Experiments have been carried out on the industrial wastewater collected from the scene. The spectral lines of As element were obtained. The calibration curve of the line intensities versus the concentrations of the As element was acquired by the experiment. The calibration curve can be used for the quantitative analysis of arsenic element with an unknown concentration in the industrial wastewater. The results showed that the LIBS technique can be applied in the rapid detection of As element in industrial wastewater, and has wide range of applications.
2009 Vol. 29 (06): 1675-1677 [Abstract] ( 1841 ) PDF (723 KB)  ( 454 )
1678 Quantitative Analysis of the Concentration of Br-Doping in Micro-Shell Coating with XRF
MA Xiao-jun,GAO Dang-zhong*,FENG Jian-hong,LI Yu-hong,YE Cheng-gang,LIU Yuan-qiong
DOI: 10.3964/j.issn.1000-0593(2009)06-1678-04
In inertial confinement fusion (ICF) physics experiment, the micro-shell that contains Br-doped CH coating must be characterized for doping Br concentration level. X-ray fluorescence (XRF), with its unique capability to quantitatively determine concentrations of most elements simultaneously and non-destructively, is generally the method of choice for total dopant (Z>11) concentration. In the present paper, a method to determine the dopant concentration in ICF micro-shell coating with X-ray fluorescence spectrometry is described, and the calibration model is founded by the calculation of fluorescence intensity of film and micro-shell sample. Based on the calibration model, the fluorescence intensity vs concentration of Br-doped CH coating of micro-shell was obtained. The experiment result shows that X-ray fluorescence spectrometry is a nondestructive and accurate method of measurement of coating dopant in the inertial confinement fusion micro-shell sample, and the measuring error is about 5% for Br doped CH coating of micro-shells with 10 micron thickness coating.
2009 Vol. 29 (06): 1678-1681 [Abstract] ( 279 ) PDF (667 KB)  ( 372 )
1682 Comparison of Four Kinds of Measurement Techniques for Wood Microfibril Angle
HUANG Yan-hui1, FEI Ben-hua1*,ZHAO Rong-jun2
DOI: 10.3964/j.issn.1000-0593(2009)06-1682-05
X-ray diffraction technique, pit aperture observing technique, polarized light microscope technique and near infrared spectrum technique were used separately to test the wood microfibril angle of Chinese fir, and the results were as follows: For the identical tree of Chinese fir, the average microfibril angle obtained by the polarized light microscope technique was the biggest, followed by those obtained by X-ray diffraction technique, and then by polarized light microscope technique, but the difference in the average microfibril angle was not significant. For the different annual rings, the microfibril angle obtained by X-ray diffraction technique became the biggest after the 20th annual ring, the fluctuation of the microfibril angle got by the pit aperture observing technique were big, but the fluctuation got by the polarized light microscope technique was just the reverse. The measurement value curves got by the three techniques were fitted well, and the difference in the average microfibril angle was not significant between different annual rings. For the microfibril angle of the same annual ring, the difference between the maximum and the minimum value tested by the polarized light microscope technique was less than 4°, but the difference tested by the pit aperture observing technique achieved 21.53°, and the standard deviation achieved 4.75. The near infrared spectrum and the X-ray diffraction techniques were all called nondestructive testing techniques. The model set up by the two techniques was very good because of its high prediction and repeatability, and the model was also good for online analysis. The R2 of calibration model and tested model achieved 0.81 and 0.75 respectively,and the standard error of calibration and prediction were 1.79 and 2.02 respectively. In addition, the near infrared spectrum technique could be also used with the other three techniques to predict the wood microfibril angle,showing the superiority of the near infrared spectrum technique. Meanwhile, the advantages and shortcomings were analyzed for the four kinds of measurement techniques.
2009 Vol. 29 (06): 1682-1686 [Abstract] ( 1531 ) PDF (1178 KB)  ( 427 )
1687 Determination of Trace Elements in Electrical Absorption Prospecting Polyform Sample by Inductively Coupled Plasma Mass Spectrometry
SHI Yi-hua, YANG Zhong-ping, HUANG Jian-hui, ZHOU Qi-ming, XIONG Chuan-xin
DOI: 10.3964/j.issn.1000-0593(2009)06-1687-04
An ICP-MS method was established for the determination of sixteen trace elements, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Nb, Mo, Ag, Cd, Au, Tl, Pb and Bi in electrical absorption prospecting polyform. Three methods for polyform samples (ashing method, extraction by HNO3+H2O2 and digestion with aqua regia) were compared and the results showed that the second method is the best one. The best operational paramenters of X series ICP-MS were confirmed, the inner standard 103Rh and 185Re were selected for the determination of elements, and analysis of isotopes interference correction equations was established. Satisfactory linearity of working curves of the sixteen trace elements was obtained, giving all their correlation coefficients over 0.999 8. The determination limit of the analytes was in the range of 0.001-2.2 μg·g-1. The precision was 1.39%-4.84%, and the recoveries were between 94.86% and 105.2%. The method is sensitive, quick and simple and has been applied to the analysis of a great number of polyform samples.
2009 Vol. 29 (06): 1687-1690 [Abstract] ( 1774 ) PDF (476 KB)  ( 409 )
1691 The Zonal Characterization of Elemental Concentrations in Brown Rice of Core Collection for Rice Landrace in Yunnan Province by ICP-AES
ZENG Ya-wen1, 3, WANG Lu-xiang2, PU Xiao-ying1, DU Juan1, YANG Shu-ming1, LIU Jia-fu2, TAI Li-mei1, 3
DOI: 10.3964/j.issn.1000-0593(2009)06-1691-05
In the present paper, the contents of 8 elements in brown rice of 789 accessions core collection for rice landrace from 16 prefectures of five rice regions in Yunnan province were determined by ICP-AES technique. The method proves to be simple, rapid, highly sensitive and accurate, and can be used to determine many elements at the same time. Its recovery ratio obtained by standard addition method ranged from 97.1% to 110.2%, and its RSD was from 0.7% to 4.4%. The analytical results showed that the elemental concentrations (mg·kg-1) in brown rice are in turn of P(3 834.83±486.49)>K(2 567.72±336.74)>Mg(2 567.72±336.74)>Ca(153.67±55.90)>Zn(33.35±13.65)>Fe(32.08±25.51)>Cu(14.22±11.85)>Mn(13.58±3.22). The highest P content is in brown rice from the northwest Yunnan with the rich nonferrous metals and most abundance of biodiversity in the world, the highest Ca, Mg, Fe and Zn concentrations are in brown rice from the middle Yunnan with early cambrian fauna and phosphorite enrichment, and the highest Cu and Mn contents are in brown rice from the southwest Yunnan with the prominent crop diversity. The distributing zones with the highest P and K, middle Ca, Mg and Mn and lowest Fe and Zn in Yunnan are the enrichment zone of minal resources and largest biodiversity. As far as we know, this is the first report that the zonal characterstics of mineral elemental concentractions in brown rice are associated with a lot of factors, such as biodiversity center, enrichment zone of minal resources, origin of life, mountain ranges and rivers and so on, and further it was deduced that the asymmetry of distribution for mineral elements and its reciprocity of mountain ranges and rivers are the key of origin of life. The above results provided reliable data and theory bases for the malnourished Fe and Zn and Ca for 4 billion people in the world, origin of life, the genetic breeding and production of functional rice.
2009 Vol. 29 (06): 1691-1695 [Abstract] ( 547 ) PDF (806 KB)  ( 441 )
1696 Content of Rare Earth Elements in Wild Hypericum Japonicum Thunb
WEI Zhen-lin1, RUI Yu-kui2*, TIAN Zhi-huan1
DOI: 10.3964/j.issn.1000-0593(2009)06-1696-02
Rare earth elements are important nutritional elements for human health, and today more and more attention has been paid to the effective components in Chinese traditional medicine, especially to rare earth elements. Fifteen rare earth elements in wild hypericum japonicum Thunb were analyzed by the methods of ICP-MS. The results showed that the concentrations of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Tm, Lu and Y ranged from 6 ng·g-1·DW to 14 522 ng·g-1·DW, and among them the concentrations of La, Ce and Nd were higher than 2 000 ng·g-1·DW. Compared with the concentration of rare earth elements in rice, corn, wheat and barley, the total concentration of rare earth elements in hypericum japonicum Thunb was much higher, which could be the mechanism of curative effect of hypericum japonicum Thunb on liverish diseases. The character of elements and the content of rare earth elements in soil should be responsible for the difference, but the distributive mechanism of rare earth elements in hypericum japonicum Thunb should be further studied.
2009 Vol. 29 (06): 1696-1697 [Abstract] ( 326 ) PDF (237 KB)  ( 464 )
1698 Study on the Adsorption Behavior of Nickel on Potassium Tetratitanate Whisker by Flame Atomic Absorption Spectrometry
XU Wan-zhen, YAN Yong-sheng*, YANG Mo-hui, JING Jun-jie
DOI: 10.3964/j.issn.1000-0593(2009)06-1698-04
The adsorption behavior of Ni(Ⅱ) on potassium tetratitanate whisker was studied systemically by FAAS, seeing about the reasons for absorption, disentanglement and the effect of interfering ions on the recovery. The preconcentration method was simple, quick and had good selectivity. The adsorption rate of Ni(Ⅱ) by potassium tetratitanate whisker was 100% at pH 5.0 and Ni(Ⅱ) could be eluted from potassium tetratitanate whisker with hydrochloric acid (C: 0.5 mol·L-1), shake time exceeding 5 min,stick time exceeding 1.5 h, and the disentanglement ratio exceeding 90%. The relative standard deviation (RSD) was 2.6%. The results obtained indicate that the potassium tetratitanate whisker has good regenerate capability.
2009 Vol. 29 (06): 1698-1701 [Abstract] ( 498 ) PDF (622 KB)  ( 413 )
1702 RVM Supervised Feature Extraction and Seyfert Spectra Classification
LI Xiang-ru1, 2, 5,HU Zhan-yi1,ZHAO Yong-heng3,LI Xiao-ming4
DOI: 10.3964/j.issn.1000-0593(2009)06-1702-05
With recent technological advances in wide field survey astronomy and implementation of several large-scale astronomical survey proposals (e.g. SDSS, 2dF and LAMOST), celestial spectra are becoming very abundant and rich. Therefore, research on automated classification methods based on celestial spectra has been attracting more and more attention in recent years. Feature extraction is a fundamental problem in automated spectral classification, which not only influences the difficulty and complexity of the problem, but also determines the performance of the designed classifying system. The available methods of feature extraction for spectra classification are usually unsupervised, e.g. principal components analysis (PCA), wavelet transform (WT), artificial neural networks (ANN) and Rough Set theory. These methods extract features not by their capability to classify spectra, but by some kind of power to approximate the original celestial spectra. Therefore, the extracted features by these methods usually are not the best ones for classification. In the present work, the authors pointed out the necessary to investigate supervised feature extraction by analyzing the characteristics of the spectra classification research in available literature and the limitations of unsupervised feature extracting methods. And the authors also studied supervised feature extracting based on relevance vector machine (RVM) and its application in Seyfert spectra classification. RVM is a recently introduced method based on Bayesian methodology, automatic relevance determination (ARD), regularization technique and hierarchical priors structure. By this method, the authors can easily fuse the information in training data, the authors’ prior knowledge and belief in the problem, etc. And RVM could effectively extract the features and reduce the data based on classifying capability. Extensive experiments show its superior performance in dimensional reduction and feature extraction for Seyfert classification.
2009 Vol. 29 (06): 1702-1706 [Abstract] ( 230 ) PDF (637 KB)  ( 428 )
1707 Comparison of Dispersion Parts of Conventional Spectrometers
YANG Huai-dong, CHEN Ke-xin, HUANG Xing-yue, HE Qing-sheng, JIN Guo-fan
DOI: 10.3964/j.issn.1000-0593(2009)06-1707-06
Innovation of conventional spectrometers is of actual technical and economical value. It is also an important way to accelerate the development of spectroscopic instruments. When improving a conventional spectrometer, its dispersion part is pivotal, because it is decisive to the basic performance of the spectrometer. In the present paper, the typical dispersion parts of conventional spectrometers are compared to feature them and find the evolution force among them. The basic characters of the dispersion parts, including spectral range, dispersion power, resolution and throughput, are compared separately and comprehensively by reviewing their decisive factor, formula and typical data. The results not only conclude the feature and the complementariness of the dispersion parts, but also indicate that the trade-off between resolution and throughput is ubiquitous in traditional spectrometers. Further reviewing from this point, the evolution history of traditional spectrometers shows that the conflict between resolution and throughput is an important evolution force. This is a new way to understand the evolution of traditional spectrometers. Moreover, dealing with the trade-off between resolution and throughput correctly will help to analyze and settle the core problem of spectrometers.
2009 Vol. 29 (06): 1707-1712 [Abstract] ( 1074 ) PDF (1020 KB)  ( 389 )
1713 A Micro-Silicon Multi-Slit Spectrophotometer Based on MEMS Technology
HAO Peng1, 2, WU Yi-hui1*, ZHANG Ping1, LIU Yong-shun1, ZHANG Ke1, 2, LI Hai-wen1
DOI: 10.3964/j.issn.1000-0593(2009)06-1713-04
A new mini-spectrophotometer was developed by adopting micro-silicon slit and pixel segmentation technology, and this spectrophotometer used photoelectron diode array as the detector by the back-dividing-light way. At first, the effect of the spectral bandwidth on the tested absorbance linear correlation was analyzed. A theory for the design of spectrophotometer’s slit was brought forward after discussing the relationships between spectrophotometer spectrum band width and pre-and post-slits width. Then, the integrative micro-silicon-slit, which features small volume, high precision, and thin thickness, was manufactured based on the MEMS technology. Finally, a test was carried on linear absorbance solution by this spectrophotometer. The final result showed that the correlation coefficients were larger than 0.999,which means that the new mini-spectrophotometer with micro-silicon slit pixel segmentation has an obvious linear correlation.
2009 Vol. 29 (06): 1713-1716 [Abstract] ( 1091 ) PDF (684 KB)  ( 399 )
1717 The Analysis of the Sampling Modulation Transfer Function and the Influence on the Gaussian Spectra
ZHAO Lie-feng,XU Zhi-hai*, FENG Hua-jun, LI Qi
DOI: 10.3964/j.issn.1000-0593(2009)06-1717-04
As the parameters of the photoelectric detector have important effects on the performance of the dispersive spectrometers, it is necessary to detail the discrete sampling process of the photoelectric detector array. In the present paper, the sampling model was setup, and the effects on the sampling results caused by the spatial frequency of the cosine signal, the width of the sampling pixel, and the initial phase of the sampling pixel position to the crest of the input cosine signal were discussed thoroughly in the frequency domain. By introducing the integral function, a general expression of the sampling modulation transfer function was given, and the concept and expression of the average sampling modulation transfer function was proposed. Since that expression eliminates the effect of initial phase, it is much more convenient to the practical applications. For the typical Gaussian spectrum produced by the dispersive spectrometer, the Fourier transform result of that spectrum was multiplied by the average sampling modulation transfer function to produce a functional expression of the modulation transfer function of the whole system. The average aliasing error of the sampling process was expressed as a function of spatial frequencies; the relationship between the peak value of the average aliasing error and the width of the Gaussian spectrum was discussed; and the critical value of the spectrum width to restore this spectrum precisely was proposed. That critical value is significant for providing guidance to the design and fabrication of dispersive spectrometers.
2009 Vol. 29 (06): 1717-1720 [Abstract] ( 545 ) PDF (809 KB)  ( 432 )
1721 Design and Simulation of the NIR Micro-Spectrometer Optical System
WANG Ling-fang, WEN Zhi-yu, XIANG Xian-yi
DOI: 10.3964/j.issn.1000-0593(2009)06-1721-05
Based on the working principle of analyzing spectrometer and the theory of optical design, to make the system miniature, and with a certain spectral range and resolution requirements as specific design objectives, a cross-C-T micro-structure based on a plane diffraction grating spectrophotometer of the near-infrared spectrometer was put forward; ZEMAX was used for design and optimizing and simulating analysis of micro-near-infrared spectrometer in the optical system. The result showed that the micro-optical system’s spectral range was 900-1 700 nm, resolution was <10 nm, spectrum broadening was 12.74 mm, F number was 8.128 388, and the system volume was 51.26 mm×41.81 mm×22 mm, and these all satisfy the requirements. It solved the micromation of the optical system of the spectrometer, and therefore, contributed to the micromation of the spectrometer itself.
2009 Vol. 29 (06): 1721-1725 [Abstract] ( 2389 ) PDF (10310 KB)  ( 610 )