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2007 Vol. 27, No. 04
Published: 2007-04-26
 
       光谱学与光谱分析
625 The Photoluminescence Characteristics of Organic Multilayer Quantum Wells
ZHAO De-wei, SONG Shu-fang, ZHAO Su-ling, XU Zheng, WANG Yong-sheng, XU Xu-rong*
By the use of multi-source high-vaccum organic beam deposition system, the authors prepared organic multilayer quantum well structures, which consist of alternate organic small molecule materials PBD and Alq3. Based on 4-period organic quantum wells, different samples with different thickness barriers and wells were prepared. The authors measured the lowest unoccupied molecular orbit (LUMO) and the highest occupied molecular orbit (HOMO) by electrochemistry cyclic voltammetry and optical absorption. From the energy diagrams, it seems like type-I quantum well structures of the inorganic semiconductor, in which PBD is used as a barrier layer and Alq3 as a well layer and emitter. From small angle X-ray diffraction measurements, the results indicate that these structures have high interface quality and uniformity. The photoluminescence characteristics of organic multilayer quantum wells were investigated. The PL peak has a blue-shift with the decrease of the well layer thickness. Meanwhile as the barrier thickness decreases the PL peaks of PBD disappear gradually. And the energy may be effectively transferred from PBD to Alq3,inducing an enhancement of the luminescence of Alq3.
2007 Vol. 27 (04): 625-628 [Abstract] ( 1747 ) PDF (1101 KB)  ( 640 )
629 Preparation of α-Gd2(MoO4)3 Red Emitting Phosphor for White Light Emitting Diodes and Its Luminescence Study
ZHAO Xiao-xia1, 2,WANG Xiao-jun1*,CHEN Bao-jiu1, 3,MENG Qing-yu1, 2,YAN Bin1, 2,DI Wei-hua1, 2
A novel red phosphor α-Gd2(MoO4)3∶Eu was synthesized by conventional solid state reaction method with the starting materials: Gd2O3,MoO3 and Eu2O3. The effects of flux and Eu concentration on the crystal structure, morphology and luminescent properties of the phosphors were investigated. The results showed that non-agglomeration phosphors with regular morphology and fine size were produced after the mixture being calcined at 800 ℃ for 4h with 3% NH4F as flux. The main emission peak of the samples is at 613 nm. The excitation spectrum showed that this phosphor can be effectively excited by ultraviolet (UV)(395 nm) and blue (465 nm) light, nicely fitting in with the widely applied output wavelengths of ultraviolet or blue LED chips. The α-Gd2(MoO4)3 phosphor may be a good candidate phosphor for solid state lighting application.
2007 Vol. 27 (04): 629-633 [Abstract] ( 1865 ) PDF (1342 KB)  ( 504 )
634 Synthesis of the Red Long Afterglow Phosphor Gd2O2S∶Eu, Mg, Ti by Microwave Radiation Method and Its Luminescent Properties
ZHAI Yong-qing,LIU Yuan-hong,MENG Yuan,ZHANG Shao-yang
Gd2O2S∶Eu, Mg, Ti, a novel red long afterglow phosphor, was synthesized in microwave field. The synthesized phosphors were investigated respectively by XRD, SEM and fluorescence spectrophotometer. The results show that Gd2O2S∶Eu, Mg, Ti phosphors possess hexagonal crystal structure, which is similar to that of Gd2O2S. The particles of Gd2O2S∶Eu, Mg, Ti phosphors are basically spherical in shape，with good dispersing. The mean particle size is 1-2 μm. The excitation spectrum is a broad band and the main peak is at 360 nm. Moreover, excitation peaks at 400, 422 and 472 nm were found in the excitation spectrum. The emission spectrum shows that Gd2O2S∶Eu, Mg, Ti has narrow emission peaks. The emission peaks are ascribed to Eu3+ ions transition from 5DJ(J= 0, 1, 2) to 7FJ(J=0, 1, 2, 3, 4). With the increase in Eu3+ molar ratio, the emission peaks at 586, 557, 541, 513, 498, 471 and 468 nm in the blue and green region weaken gradually relative to the main emission peak at 627 nm. Therefore the red emitting at 627 nm becomes strong gradually. When the molar ratio is 6%, the red emitting becomes the strongest. The Ti and Mg co-doping can obviously improve its long-afterglow property.
2007 Vol. 27 (04): 634-638 [Abstract] ( 1522 ) PDF (1214 KB)  ( 689 )
639 Preparation and Photoluminescence Investigation of Europium-Doped Zinc Oxide Nanocrystalline
SONG Guo-li,SUN Kai-xia, YANG You-tong
Europium-doped zinc oxide nanocrystalline was successfully prepared by sol-gel process. Photoluminescence spectrum (PL), Photoluminescence excitation spectrum(PLE), and X-ray diffraction pattern(XRD) of nanocrystalline ZnO∶Eu3+ with excitation wavelength 395 nm were measured at room temperature. The XRD pattern indicates that nanocrystalline ZnO∶Eu3+ has a hexagonal wurtzite structure and is polycrystalline. The mean grain size of nanocrystalline ZnO∶Eu3+ was calculated by Debye-Scherrer formula. The luminescence process of Eu3+-doped zinc oxide nanocrystalline was investigate using PL and PLE. Emission of 5D0→7F1(595 nm), 5D0→7F3(653 nm)，5D0→7F2(611 nm) of Eu3+ ions, and a weak and wide visible band of ZnO were observed. Also, the photoluminescence of nanocrystalline ZnO∶Eu3+ exhibits a blue-shift. An energy transfer from excited states of ZnO hosts to doped Eu3+ ions centers was disclosed by the fact that that photoluminescence intensity maximum of nanocrystalline ZnO∶Eu3+ changs with the doping concentration of Eu3+.
2007 Vol. 27 (04): 639-642 [Abstract] ( 413 ) PDF (1329 KB)  ( 521 )
643 Optical and Electrical Properties of NPB/Alq3 Organic Quantum Well
HUANG Jin-zhao, XU Zheng, ZHAO Su-ling, ZHANG Fu-jun, WANG Yong
In the present paper, the organic quantum-well device similar to the type-Ⅱ quantum well of inorganic semiconductor material was prepared by heat evaporation. NPB (N,N′-di-[(1-naphthalenyl)-N,N′-diphenyl]-(1,1′-biphenyl)-4,4′-diamine) and Alq3 (Tris-(8-quinolinolato)aluminum) act as the potential barrier layer and the potential well layer respectively. Besides, the single layer structure of Alq3 was prepared. In the experiments, the Frster nonradiative resonant energy transfer from the barrier layer to the well layer was identified, and the quantum well luminescence device possesses a favorable current-voltage property. The narrowing of spectrum was observed, and the spectrum shifted to blue region continuously when the applied voltage increased.
2007 Vol. 27 (04): 643-646 [Abstract] ( 1649 ) PDF (876 KB)  ( 503 )
647 Collisional Transfer of the Cs(8S) State and Excitation of High Lying Atomic States
CUI Xiu-hua1,2,MU Bao-xia2,WANG Shu-ying1,2,ZHANG Gang-tai2,YUAN Qiang-hua2,DAI Kang2,SHEN Yi-fan2*
Using selective stepwise excitation of the cesium 8S atomic level in Cs vapor, the collisional transfer and the population of the high-lying atomic states were studied in detail. At cesium densities of 1016-1017 cm-3,the rate coefficient of excitation collision[i.e., 8S+6S→6D+6S] was measured. Measurement of fluorescence intensities as a function of Cs density yields k6D=(2.4±0.5)×10-10 cm3·s-1. The 5D state was populated by the 8S→7P→5D transitions. The energy pooling collisions 5D+5D→nL+6S (nL=9D, 11S, 7F) were also studied. The rate coefficients were measured relative to the known rate coefficient of the collision [i.e. 6P+5D→6S+7D]. The densities of 6P state were combined with measured fluorescence ratios to determine rate coefficients for EP process. The average values (in unites of 10-10 cm3·s-1) for nL=9D, 11S and 7F are 6.4±3.2，1.0±0.5 and 8.4±4.2, respectively.
2007 Vol. 27 (04): 647-649 [Abstract] ( 1189 ) PDF (872 KB)  ( 508 )
650 Spectroscopy Study of Aqueous CdTe Quantum Dots Synthesized by Microwave Irradiation Method
CHEN Qi-fan1,2,YANG Dong-zhi1,XU Shu-kun1*,QU Zheng2
Water-soluble CdTe nanocrystals capped with cysteamine were synthesized rapidly in aqueous solution by microwave irradiation with controllable temperature. Absorption and fluorescence spectra showed that these prepared CdTe quantum dots had good optical properties. The structure and diameter were characterized by the transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). The effects of heating temperature，irradiation time and the concentrations of cysteamine on the growing velocity of CdTe QDs synthesized were also investigated. With the increase in the temperature and concentration of cysteamine, the nanoparticles grow faster, and for a longer reaction time, the maximum emission wavelength of the nanoparticles shows a red shift. Compared with the conventional aqueous synthesis, the microwave irradiation method showed some advantages such as the rapid velocity, good dispersibility and uniformity, narrow FWHM (full width at half maximum) and high quantum yield.
2007 Vol. 27 (04): 650-653 [Abstract] ( 1331 ) PDF (1750 KB)  ( 586 )
654 Effect of Different Sensitization on the Photoelectron Time Action in AgCl Emulsion
LAI Wei-dong, LI Xin-zheng, JIANG Xiao-li, TIAN Xiao-dong, LI Xiao-wei*
The temporal behaviors of free photoelectrons and shallow-trapped electrons were measured in the cubic AgCl emulsion with the microwave absorption and dielectric spectrum detection technique. The results indicate that the chemical sensitization makes the photoelectron decay slower than that of the unsensitized AgCl emulsion, and the decay time is prolonged in the sulfur-plus-gold sensitized emulsion, because the shallow electron trap effect of sulfur-plus-gold sensitization center restrains the recombination of photoelectron and hole. The photoelectron decay is pricked up and the decay time is shorter in sensitized emulsion than that in the unsensitized AgCl emulsion, because the J-aggregates increase the interstice silver ion density in the AgCl microcrystal and accelerate the recombination of interstice silver ions and electrons. The decay time of photoelectron in chemistry-and-spectra sensitized emulsion is also prolonged, and the shallow electron trap effect of chemical sensitization center is more distinct under the condition of spectra sensitization.
2007 Vol. 27 (04): 654-656 [Abstract] ( 351 ) PDF (939 KB)  ( 433 )
657 Influence of Eu2+ Content on the Spectral Characteristics of BaMgAl10O17∶Eu2+ Phosphors
CHEN Zhe,XIE Hong,YAN You-wei*
Nanocrsytalline Ba1-xMgAl10O17∶xEu2+ (0.05≤x≤0.4) blue-emitting phosphor was successfully prepared by low-temperature combustion synthesis. The influence of different Eu content on the spectral characteristics of Ba1-xMgAl10O17∶xEu2+ was mainly investigated. The results of XRD and SEM analysis show that the sample is single phase and its average grain size is about 30 nm. The luminescence property of Ba1-xMgAl10O17∶xEu2+ phosphor is considerably influenced by Eu2+ concentration. In an appropriate Eu2+ doping concentration range, the intensity of the fluorescence of Ba1-xMgAl10O17∶xEu2+ was increased obviously with increasing the Eu2+ doping concentration, owing to adding the number of luminescent centers and enhancing the energy transfer between Eu2+ ions. The optimum emission intensity was reached at x＝0.2. However, as the Eu2+ doping concentration was higher than 0.2, the intensity of the fluorescence was reduced, due to the concentration quenching occurrence.
2007 Vol. 27 (04): 657-659 [Abstract] ( 356 ) PDF (1186 KB)  ( 551 )
660 The Spectra of Water-Reabsorbing Spirulina Maxima at Different Light Intensity
YANG Fang1, 2,TU Fang1,BAI Yan1,ZHENG Wen-jie1,2*
The freeze-dried cells of Spirulina maxima were resuspended in NaCl isotonic solution under the condition of darkness, natural light and culture illumination respectively. Their spectra were studied after the Spirulina maxima was treated for 2, 14 and 26 h respectively. The results indicated that the peak intensity decreased gradually at different light intensity but in the same time span. The peak intensity was the highest when Spirulina maxima was put in darkness, but lowest under culture illumination. The water-reabsorbing Spirulina maxima couldn’t restore the normal photosynthesis under the dual stress of both water and light.
2007 Vol. 27 (04): 660-663 [Abstract] ( 1840 ) PDF (1892 KB)  ( 507 )
664 Study on the Reaction Mechanism of NO Removal by Pulse Corona Discharge
ZHANG Lian-shui, LIU Tao, DANG Wei, DUAN Shu-xing
Chemical reaction kinetics of NO removal by pulse corona discharge under the condition of normal atmospheric pressure was studied by using dispersive fluorescence spectrum and time-resomved spectrum. The fluorescence spectrum of NO pulse corona discharge was obtained. Moreover, dactylograms of NO, and those of the N+,O, N2,produced in the process of discharging were confirmed by attributing the fluorescence spectrum, and then the time behaviors of these particles were studied by analyzing these dactylograms. The results show that, the NO molecule turns to NO+ ion after colliding with high-energy electron, and then the NO+ ion breaks down to N+ and O. Subsequently, the N+ ion turns to N atom after absorbing an electron and then combines with another N atom, while the O atom turns to O2 molecule when combining with another O. From these results, the chemical kinetics model of NO removal by pulse corona discharge was proposed, which is helpful to increasing NO removal rate.
2007 Vol. 27 (04): 664-667 [Abstract] ( 462 ) PDF (1232 KB)  ( 506 )
668 Atmospheric CH4 Concentrations and the Correlation between CH4 and CO Concentrations
WEI Xiu-li, LU Yi-huai, GAO Min-guang, LIU Jian-guo, LIU Wen-qing, XU Liang, ZHANG Tian-shu, ZHU Jun, CHEN Jun
Methane (CH4) is an important greenhouse gas and a key molecule in tropospheric photochemistry, some more potent than CO2. The remote-sensing experiments of CH4 were carried out in the fall of 2 000 in Beijng. The 6-day records of the atmospheric CH4 concentrations were examined by means of a time-series analysis using a fast Fourier transform with a low-pass filter to elucidate the seasonal cycles and the long-term trends. The variation in the long-time trends of the CH4 concentrations in Beijing may be ascribed to the emission changes in the CH4 sources due to the human activities such as waste dumping and landfills and the emission from motor vehicles. The correlation between the CH4 and CO concentrations was analyzed.
2007 Vol. 27 (04): 668-670 [Abstract] ( 2202 ) PDF (1116 KB)  ( 569 )
671 A Novel Material with Low Infrared Target Features
GAO Hai-chao,DAI Song-tao*
As the working mode of modern detecting system is changing from single mode to compound one, materials with certain spectral characteristics are required to meet low observable demands. In the present paper, the authors designed a novel material with low target features in infrared band based on one dimensional doped photonic crystal, and investigated the influence of the composite structure on reflection spectrum. It was found that under certain conditions, a local narrow low-reflectivity region can be formed within a wide high-reflectivity band in reflection spectrum, providing a reference for the development of a new type of infrared functional materials.
2007 Vol. 27 (04): 671-674 [Abstract] ( 1166 ) PDF (1012 KB)  ( 482 )
675 Application of FTIR and XPS Technique to the Analysis of the Mixture Containing Chromium in a Low Valence State
BAI Yu-lan1, 2,XU Hong-bin1*,ZHANG Yi1,LI Zuo-hu1
Chromium has various valence states and in the process of preparing chromium oxides with low valence state of chromium, chromium compounds with different valence state of chromium can usually be produced as intermediates. Due to the difference in property of these intermediates, they always have remarkable influences on the morphological characteristics of the final product. The composition of the intermediate was very complicated in the process of synthesizing chromium oxide with low valence state of chromium by reducing potassium chromate with hydrogen. To explore the reaction mechanism and further optimize the technical process, the composition of the intermediate obtained from the reduction of K2CrO4 with hydrogen was investigated through the combination of XPS, FTIR and XRD. The XPS results revealed that the intermediate of reducing potassium chromate with hydrogen is trivalent chromium compound;the results of FTIR and XRD indicated that the intermediate mainly consists of Cr(OH)3·nH2O, HCrO2 and a little amount of KOH or KCrO2. On the basis of the above analysis of the intermediate, the possible reactions that occurred in the reduction process were suggested.
2007 Vol. 27 (04): 675-678 [Abstract] ( 1953 ) PDF (1303 KB)  ( 619 )
679 FTIR Measurement and Analysis Based on the Selection of Optimized Spectral Band
ZHU Jun1,2,LIU Wen-qing1,LIU Jian-guo1,LU Yi-huai1,GAO Min-guang1,XU Liang1,ZHANG Tian-shu1,WEI Xiu-li1
In active infrared remote sensing measurements, the infrared absorption caused by the presence of trace gases in atmosphere is related to the transmittance spectra in different infrared wave band. In many cases, transmittance spectra play an important role in spectsal quantitative analysis. Thus, the selection of wave band to be optimized for the measured and simulated transmittance spectra is the key in quantitative analysis. In the present paper, the optimal measurement range of transmittance is analyzed theoretically, which causes the minimum relative error of the retrieved concentration. The cross section for the measured gas based on Lorentz line shape is derived by calculation. At the same time, the transmittance spectra calibration training set is presented. The measured and analyzed band is determined for single component CO2. The optimal measurement band is determined for multi-component measurement. The simultaneous measurement of CO, CO2 and N2O with open path FTIR spectrometer system is accomplished successfully. The measured transmittance spectra are in good agreement with the reference transmittance spectra. The root mean square error of fitting results is less than 1%.
2007 Vol. 27 (04): 679-682 [Abstract] ( 1110 ) PDF (1050 KB)  ( 442 )
683 FTIR Spectroscopic Investigations on the Difference in Cartilage Composition between Youth and Elder
CHEN Wei1,ZHOU Mi2*,ZUO Jian2,WANG Li-na3,GAO Shu-qin2,LU Guo-hui2,LI Zhan-long2,LI Zuo-wei2
Cartilage of youth and elder was measured by Fourier transform infrared (FTIR). Area integrations were done on the major composition of organic and inorganic substance’s infrared bands processed using OMNIC 5.2. Calculation of the ratio of the integrated areas under the organic and inorganic substance’s peaks allowed the comparisons of the ratio brtween organic and inorganic substance’s contents. As indicated from the results, the ratio of organic to inorganic substance in youth is 5-7 times larger than that in elder, but there was a big difference in the content of lipids between youth and elder. Calculating the ratio of the integrated areas under lipids peaks (1 747 cm-1)to that under inorganic phosphates peaks, the authors can see that the content of lipids in the bone of elder is significantly higher than that of youth. The authors admitted that with the increment of age, less organic substance(collagen) (but more lipids) and more inorganic substance(phosphate, carbonate etc) is a symbol of the degeneration of cartilage. Therefore, makes the cartilage more brittle, less elastic and less wearable. This can result in the disease of bone and injuring the bone easily.
2007 Vol. 27 (04): 683-685 [Abstract] ( 1978 ) PDF (871 KB)  ( 497 )
686 Discrimination of Wood Biological Decay by Soft Independent Modeling of Class Analogy (SIMCA) Pattern Recognition Based on Principal Component Analysis
YANG Zhong1,JIANG Ze-hui1,2*,FEI Ben-hua1,QIN Dao-chun2
Wood, as a biomass materials, tends to be attacked by microorganisms, and its structure could be rapidly destroyed by biological decay. Therefore, it′s significant to rapidly and accurately detect or identify biological decay in wood. Recently, extensive research has demonstrated that near infrared spectroscopy (NIR) and soft independent modeling of class analogy (SIMCA) can be used to discriminate or detect a wide variety of food, medicine and agricultural products. The use of NIR coupled with principal component analysis (PCA)and SIMCA pattern recognition to detect wood biological decay was investigated in the present paper. The results showed that NIR spectroscopy coupled with SIMCA pattern recognition could be used to rapidly detect the biological decay in wood. The discrimination accuracy by the SIMCA model based on the training set for the non-decay, white-rot and brown-rot decay samples were 100%, 82.5% and 100%, respectively;and that for the samples for the test set were 100%, 85% and 100%, respectively. However, some white-rot decay samples were mis-discriminated as brown-rot decay, for which the main reasons might be that the training set does not have enough typical samples, and there′s a slight difference between white-rot and brown-rot decay during the early stage of decay.
2007 Vol. 27 (04): 686-690 [Abstract] ( 426 ) PDF (953 KB)  ( 520 )
691 Applications of Near Infrared Reflectance Spectroscopy Technique (NIRS) to Grassland Ecology Research
NIE Zhi-dong1,HAN Jian-guo1*,ZHANG Lu-da2,LI Jun-hui3
The technology of near infrared reflectance spectroscopy (NIRS) have been widely used in many research areas, owing to its rapidness，high efficiency, low cost and no pollution. The present paper mainly illustrates the significance of the applications of NIRS to grassland ecology research, and explains some innovative implications of near infrared reflectance spectroscopy in the determination of a variety of forage nutrients, minerals, and the components of soil, prediction of the composition of forage mixtures, animal performance, grass resistance of diseases and insect pests and other complex ecological characters, and doing research on biochemical markers, isotope discrimination and so on. By synthesizing these applications properly, it is concluded that NIRS could be used as a holistic tool in grassland ecology research to determine the chemical components, and analyze the complex dynamic character of grassland ecosystem and the total specialty of the system running. According to this paper, the authors also hope to promote the application conditions of NIRS in the grassland ecology research in China, and accelerate the modernization of research measures in this area.
2007 Vol. 27 (04): 691-696 [Abstract] ( 2388 ) PDF (924 KB)  ( 557 )
697 Prediction of Protein Content of Intact Wheat Seeds with Near Infrared Reflectance Spectroscopy(NIRS)
WANG Wei-dong, GU Yun-hong, QIN Guang-yong*,HUO Yu-ping
In the present article, the measurement of intact wheat seeds’ protein content with near infrared reflentance spectroscopy(NIRS) was studied. The wavelength range of 1 100-2 498 nm was used. The distinguishability of NIRS machine was 2 nm. Firstly the representative wheat samples with different protein contents were selected and the original spectra of wheat were obtained using NIRS machine. Then through scatter correction and maths treatment, spectrum noise were decreased. Finally regression methods used multiple linear regression, principal component regression and modified partial least squares respectively. The result showed that after optimizing all the factors, the best calibration model of equation was chosen using “first derivative”+“Standard Multiplicative Scatter Correction, SMSC”+“Modified Partial Least Squares，MPLS”. RSQ, SECV and 1-VR of the obtained calibration model were 0.94, 0.42 and 0.87 respectively. A set of representative individual wheat samples were uesed to check the model, and prediction coefficient of determination was 0.88. Protein content of wheat could be preidicted quickly and scathelessly by using the NIRS measurement. It was feasible to be used in early generation selection in wheat quality breeding process.
2007 Vol. 27 (04): 697-701 [Abstract] ( 1715 ) PDF (1225 KB)  ( 584 )
702 Discrimination among Different Brands of Coffee by Using Vis-Near Infrared Spectra
WANG Yan-yan, HE Yong*,SHAO Yong-ni, ZHANG Zhi-fei
Near infrared spectroscopy technology was used to distinguish three different brands of coffee bought from the supermarket. Two models, PCA-BP and WT-BP, were employed for the analysis and prediction of the samples. The discrimination among the different brands of coffee was based on the combination of the function of data compression in the PCA and WT technology and the ability of learning and prediction of the artificial neural network. In the experiment, 60 samples were used for model calibration and 30 for brand prediction. The result showed that both the PCA-BP and WT-BP models achieved 100% discrimination rate, and the wavelet transforms technology is superior to the principal component analysis both in time-consuming and the capability of data compression. It is indicated that the model set up by the combination of WT technology and BP neural network in the present study is rapid in analysis and precise in pattern discrimination. It can be concluded that a new approach to distinguishing pure coffee was of fered and the result of this experiment established the foundation for the determination of the raw material (coffee bean) of different brands of coffee in the market.
2007 Vol. 27 (04): 702-706 [Abstract] ( 1176 ) PDF (977 KB)  ( 928 )
707 Study on Surface-Enhanced Raman Spectroscopy of C60 Films on Ag Electrodes
SUN Yu-hua, BAO Fang, GU Wei, YAO Jian-lin, GU Ren-ao*
The thin films of C60 on Ag electrodes were studied by in situ surface-enhanced Raman spectroscopy (SERS) in acetonitrile solution and water solution respectively. The influence of C60 from bulk solution on the SERS of the adsorbed C60 was removed by pre-forming C60 films on the electrode. The results indicate that the split of some relevant Raman bands was attributed to the loss of vibrational degeneracy due to the lowering of the C60 molecular symmetry. Moreover, the surface selection rule was extended because of the influence of the surface electromagnetic field in which some forbidden modes became Raman-active. The results were similar to that of C60 molecules adsorbed on Ag electrode in the solution of C60. A weak band at about 348 and 311 cm-1 was observed for the C60 films in acetonitrile solution and in aqueous solution respectively, which could be assigned to the interaction of C60 and Ag electrode surface.
2007 Vol. 27 (04): 707-710 [Abstract] ( 400 ) PDF (941 KB)  ( 547 )
711 Study on Adsorption of Nonpolar R-Side Amino Acids on Silver Nanoparticles by FT-SERS
LI Si, ZHOU Guang-ming*,YANG Da-cheng, YU Dan-ni, PENG Hong-jun, WU Xin-jun, WANG Ning
The adsorption orientation and adsorption characteristics of aliphatic-nonpolar amino acids represented by L-methionine on silver nanoparticles were studied by FT-surface-enhanced Raman spectroscopy (FT-SERS) method with different pH and concentrations. According to the experiments，in order to get the best FT-SERS effects，the optimal concentration range of the L-methionine on silver sol is between 10-3 mol·L-1-10-4 mol·L-1. The FT-SERS effects and adsorption model change with pH;The SERS are poor when pH is near the isoelectric point or over 11 or 3. The interaction of L-methionine with Ag nanoparticles is the physical and chemical adsorption by NH3,COO-，S，which could also be effected by pH. From the results and previous reports on this aspect, the general rules of the adsorption model and the orientation of the aliphatic-nonpolar amino acids on silver nanoparticles were speculated, which would be useful for the study of amino acids, protein, peptide, enzyme etc.
2007 Vol. 27 (04): 711-715 [Abstract] ( 2470 ) PDF (1199 KB)  ( 612 )
716 Study on the Modified Surface Layers of the CIGS Thin Films by Raman Spectra
LIU Wei1,SUN Yun2,LI Feng-yan2,HE Qing2,LI Chang-jian2,TIAN Jian-guo1*
In the present paper, the properties of Cu(In1-xGax)Se2 (CIGS) thin film absorber materials for the solar cells obtained by selenization of the precursors with In-rich or CuGa-rich surface layers were studied by XRD, SEM and Raman spectra. The photovoltaic devices based on the absorbers were measured and analyzed by illuminated J-V curve subsequently. The performance of the device constructed by the absorbers obtained by selenization of the precursors with CuGa-rich surface layer was improved greatly compared to that with In-rich surface layer. Through Raman spectra measurement, it was found that the Raman peak of the A1 mode was shifted for the CuGa-rich one, which is verified that the band gap of the surface layers was elevated. Moreover the value of increased Ga contents within the surface region of films were calculated by the relation between the Raman shifts and the Ga contents. As a result, the devices based on the thin films with the elevated surface energy band by selenizing the precursors with the CuGa-rich surface layer improved further the Voc and FF by about 74 mV and 8% respectively compared to that of corresponding to the one with In-rich surface layers, so that the conversion efficiency of the photovoltaic devices based on these thin films with CuGa-rich surface layer was improved by up to 9.4%. Meanwhile Raman scattering spectroscopy has proven to be a very powerful and useful technique for the surface analysis of such thin film solar cell semiconducuor materials.
2007 Vol. 27 (04): 716-719 [Abstract] ( 1868 ) PDF (1435 KB)  ( 468 )
720 The Study on DRS and Raman Spectroscopy of Surface Modified TiO2/SiO2
SANG Li-xia1,ZHONG Shun-he2,MA Chong-fang1
TiO2/SiO2 were prepared by surface reaction of silica with an acetone solution of Ti(i-OC3H7)nCl4-n,where n=0-2. Results of XRD, Raman and UV-Vis DRS showed that two types of Ti species, small particles of anatase-type TiO2 and noncrystalline TiO<i>x species, are molecularly dispersed on the silica surface. Relative to the TiO2 bulk, a blue-shift in the bandgap adsorption edge of TiO2/SiO2 was observed due to the quantum size effects. The bandgap energy (Eg) of TiO2/SiO2 is 3.96 eV. When M(Pd, Cu, Ni) is deposited on TiO2/SiO2,the adsorption spectra extend to visible light region and the bandgap adsorption edge red shifts with respect to TiO2/SiO2. Compared with that of Pd, the deposition of Cu and Ni on TiO2/SiO2 has more effects on LMCT transition (O2-→Ti4+) of Ti atoms. And the bandgap energy of Cu-TiO2/SiO2 decreases to 3.69 eV. Similarly, the photon adsorption property for visible light can be improved relatively by the incorporation of MoO3 on TiO2/SiO2,At higher MoO3 loadings, the Mo-O-Ti coupled structure can be formed through the interaction between MoO3 and TiO2,which made the bandgap energy decrease to 3.81 eV.
2007 Vol. 27 (04): 720-724 [Abstract] ( 1173 ) PDF (1621 KB)  ( 418 )
725 The Study on Raman Spectra of Si Nanowires
TAN Yan, TANG Yuan-hong*,PEI Li-zhai, CHEN Yang-wen
Phonon confinement effect results in an redshift and asymmetric broadening in the low-frequency side of Raman spectra of intrinsic silicon nanowires(SiNWs), but is not the only factor impacting the Raman spectrum of SiNWs. At high incidence laser power densities, laser heating gives a redshift and symmetric broadening, and Fano interference between the scattering from the k=0 optic phonon and the electronic continuum scattering from laser-induced carriers gives an asymmetric line shape, i.e. Fano line shape. Furthermore, due to phonon confinement effect, the fundamental k=0 Raman selection rule is relaxed, allowing phonons away from the Brillouin zone center to participate Raman scattering too, therefore, some new weak Raman signals appear at about 604 and 423 cm-1 in addition to the usual silicon peaks at 520, 302 and 964 cm-1 for silicon nanowires with small diameter.
2007 Vol. 27 (04): 725-729 [Abstract] ( 1295 ) PDF (1608 KB)  ( 659 )
730 Study on the Interactions between Rhizoma Coptidis and Radix Glycyrrhiza
LI Sai-jun, WANG Fan, ZHAO Jing-jing, CHEN Hui, WU Jin-guang*
Ancient prescription rhiaoma coptidis powder is a kind of traditional Chinese medicine compounds(TCMC) which is composed of rhizoma coptidis(RC) and radix glycyrrhiza(RG). In the present investigation, the compositions in solutions and precipitates of single decocted RC and RG, and decocted RC-RG mixture were studied by FTIR spectroscopy, HPLC technique and TOF-MS method. The components of decocted RC-RG mixture are different from those of the addition of RC and RG, suggesting that the interactions between RC and RG occurred. The results of FTIR spectroscopic characterization, and HPLC and TOF-MS measurements demonstrated that in both solutions and precipitates some new chemical compounds formed, while some components in the original single decocted RC and RG were restrained in the mixed system, indicating that RG plays an important role in this TCMC-rhizoma coptidis powder.
2007 Vol. 27 (04): 730-734 [Abstract] ( 2664 ) PDF (1183 KB)  ( 841 )
735 Study on Fluorescence Characteristics of Dissolved Organic Matter during Municipal Solid Wastes Composting with Inoculation Microbes
WEI Zi-min1, 2,XI Bei-dou1,ZHAO Yue2,WANG Shi-ping3*,LIU Hong-liang3
Dissolved organic matter (DOM) of municipal solid waste (MSW) consists of minerals, water, ash and humic substances, and is known to enhance plant growth. In the present study, inoculating microbes (ZJ, MS) were used in municipal solid wastes composting, and the composting process was assisted using industrial technology. During composting, DOM was extracted from compost and purified. The spectroscopic characteristics of the DOM were determined using UV, FTIR, and fluorescence spectroscopy. The result showed that at the final stage of composting, the UV, FTIR and fluorescence spectra were similar in shape among all treatments, but the characteristic peaks intensities were different compared with the control process (CK) with no inoculation microbes, and the DOM spectral characteristics of inoculation with microbes showed that the shoulder peak of UV spectra near 280 nm obviously weakened;The FTIR spectrum exhibited a reduction in polysaccharides, and a relative increase in aromatic components;the fluorescence spectra exhibited an increase in aromatic compounds, and the fluorescence spectra of DOM were similar to that of fulvic acid in sewage sludge. Indeed, the UV, FTIR and fluorescence spectra all led to the same conclusion, i.e. treatments by inoculation with microbes led to a greater degree of aromatization of DOM than in CK, in the following order: MS+ZJ>ZJ>MS>CK. At final stage of MSW composting, the DOM spectra of the mixed inoculation of MSW with MS and ZJ was more similar to fulvic acid in sludge. It was indicated that DOM from composting with inoculation MS and ZJ has more activity than that of other treatments.
2007 Vol. 27 (04): 735-738 [Abstract] ( 2189 ) PDF (1141 KB)  ( 677 )
739 The Ground Reflectance Spectrum Retrieval from ETM Images
东北师范大学城市与环境科学学院, 吉林 长春 130024
Retrieval of ground reflectance spectrum from satellite sensor digital count requires knowledge of the atmospheric conditions. Images of spectral radiance from ground-atmosphere system recorded by the multi-spectral imager ETM which boarded Landsat-7 sensor can retrieve the ground reflectivity spectrum. The uncertainty of reflectance spectrum retrieval is no more than 17% at the band 1 of ETM, and less than 10% at the band 2 and 3 of ETM. It is superior to those arithmetics widely used at present. Retrieval of ground radiance spectrum from ground-atmosphere system can be used to synthesize the sRGB true color image, but the definition is not excellent. And it was proved that the color of the images can not reflect the actual nature of earth objects before being adjusted. And the accuracy of interpretation based on true color synthesized images is superior to those based on the source images. So the precision of such reflectance spectrum retrieval is not as good as expected if applied to the true color photography on the ground.
2007 Vol. 27 (04): 739-742 [Abstract] ( 2274 ) PDF (1002 KB)  ( 466 )
743 Determination of the Conversion of Styrene with UV Spectroscopy in Microemulsion Polymerization Induced by Ultrasound
WANG Ya-qiong, XIN Hong-qun, XU Wen-lin
The determination of the conversion of styrene with UV spectroscopy was studied in microemulsion polymerization induced by ultrasound. The effects of SDS, pentrol and polystyrene on the styrene spectra were discussed. The experimental results show that the concentration of styrene in microemulsion polymerization system can be determined quantitatively at the wavelength of 247nm by UV spectroscopy, and the relationship between the styrene concentration and the absorbence is linear in the range of 9.7×10-6 mol·L-1-6.95×10-5 mol·L-1,meanwhile the molar absorptivity is 1.384×104 L·mol-1·cm-1. The SDS and pentrol presented in microemulsion polymerization system have no effects on the determination of the conversion of styrene. Polystyrene, a resultant in the process of microemulsion polymerization, could be removed by adding 95% alcohol to the microemulsion polymerization system and making polystyrene to be precipitated. Residual polystyrene does not affect the determination of the concentration of styrene. Comparing the results of UV spectroscopy with those of the chemical analysis and gravimetric analysis, the determination of the conversion of styrene by UV spectroscopy is feasible, and the process is simple and easy.
2007 Vol. 27 (04): 743-746 [Abstract] ( 429 ) PDF (1420 KB)  ( 783 )
747 Reflectance Spectroscopic Characterization of Thallium Wastewater Treatment by Pyrite and Pyrite Slag
ZHANG Ping1, 2,CHEN Yong-heng1,LIANG Min-hua1,YAO Yan1
The surface hydroxyls in pyrite and slag were investigated, and the result showed that the hydroxyls in pyrite slag were induced by residual pyrite. The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) indicated that the surface hydroxyls in pyrite and slag reacted with thallium ion in the process of wastewater treatment. The 3 550 cm-1 peak and 3 402 cm-1 peak weakened after pyrite and slag treatment, nevertheless the 3 550 cm-1 peak lowered and shifted to higher frequencies by about 70 cm-1 with slag treatment. The reflectance spectroscopy in visible region was used to characterize the change of particle and specific surface in these treatment process, and furthermore, the fact that the activity of both pyrite and slag increased in repetitive use was explained.
2007 Vol. 27 (04): 747-749 [Abstract] ( 1544 ) PDF (1372 KB)  ( 574 )
750 Synthesis and Characterization of Silver-Intermediates in the Development Process of Photothermographic Material
FAN Ming-ming, BAO Hong-bin, ZHANG Yun, JIE Yu, WANG Hong*
Photothermographic material (PTG) is one of the frontier subjects in the field of photographic science during the last decade. In the present paper, the silver-intermediate in development process of PTG material-disilver phthalate (Ag2PA) was prepared by the liquid deposition method, and Ag2PHZ2PA·H2O complex was synthesized successfully by liquid dispersion means using Ag2PA and phthalazine (PHZ) as the reactants. The composition of Ag2PA and Ag2PHZ2PA·H2O was determined by ICP-AES and elemental analysis, and the two silver-intermediates were characterized with XRD, FTIR, TG and DSC. As a result, the silver-intermediates in the development process of PTG material, Ag2PA and Ag2PHZ2PA·H2O, were qualitatively analyzed respectively.
2007 Vol. 27 (04): 750-753 [Abstract] ( 343 ) PDF (1546 KB)  ( 448 )
754 Study on the Interaction between Brucine and Bovine Serum Albumin
WANG Chun, WU Qiu-hua, WANG Zhi*,HAN Dan-dan, SONG Shuang-ju
The interaction between brucine and bovine serum albumin (BSA) was investigated using fluorescence spectroscopy (FS) and ultraviolet spectroscopy (UV). The experimental results showed that the brucine quenches the inner fluorescence by forming a brucine-BSA complex. It was found that both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The apparent binding constants (KA) between brucine and BSA were 6.3×103 (27 ℃) and 7.7×103 (37 ℃)，and the binding sites (n) were 0.94(27 ℃) and 0.97 (37 ℃). According to the Frster theory of non-radiation energy transfer, the binding distances (r) were also obtained. The process of binding was a spontaneous molecular interaction in which entropy increased and Gibbs free energy decreased, indicating that the interaction between brucine and BSA was driven mainly by hydrophobic force.
2007 Vol. 27 (04): 754-757 [Abstract] ( 2259 ) PDF (897 KB)  ( 454 )
758 Simultaneous Determination of Sm(Ⅲ) and Y(Ⅲ) by Spectrophotometry with a Wavelet Packet Transform Latent Variable Regression
GAO Ling1,LI Jin-mei2,REN Shou-xin1
A wavelet packet transform latent variable regression (WPLVR) method was developed to perform simultaneous quantitative analysis of Sm(Ⅲ) and Y(Ⅲ). The quality of the noise removal was improved by combining wavelet packet transform with latent variable regression (VLR). Wavelet packet representations of signals provided a local time-frequency description, thus in the wavelet domain, the quality of the noise removal can be improved. The latent variables were made by projecting the wavelet packet processed signals onto orthogonal basis eigenvectors. The latent variable is expressible in term of linear combination of the original signals. By this method one can obtain highly selective information from unselective full-spectrum data. Through optimization, the wavelet function and wavelet packet decomposition levels (L) were selected. Two programs, PWPLVR and PFTLVR, were designed to perform WPLVR and Fourier transform latent variable regression (FTLVR) calculations. Experimental results showed that both methods were successful, but the WPLVR methed was better than FTLVR.
2007 Vol. 27 (04): 758-761 [Abstract] ( 331 ) PDF (889 KB)  ( 428 )
762 Excitation-Wavelength Dependent Photoluminescence from Porous Silicon
HUANG Yuan-ming, ZHOU Fu-fang
With the technique of fluorescence spectral analysis, the dependence of the fluorescence from porous silicon on the excitation wavelength was investigated. It was found when the excitation wavelength decreases from 650 to 340 nm, the fluorescence spectrum of porous silicon blue shifts continuously from 780 to 490 nm. Using scanning electron microscopy (SEM) and computer simulation, the cross-sectional structures of porous silicon were studied. The authors’ results showed that the microstructures of porous silicon exhibit fractal characteristics. With the additional information extracted from the excitation spectra of porous silicon, the authors’ results can be interpreted in terms of the quantum size effect and the fractal structures of porous silicon.
2007 Vol. 27 (04): 762-764 [Abstract] ( 1106 ) PDF (1177 KB)  ( 516 )
765 Study on the Ternary Complex of FLRX，Zinc(Ⅱ) and BSA by the Method of Fluorescence
WU Gen-hua, WANG Jie, GUO Chang, WANG Dong-xiang, ZHAO Ting-ting
The influences of fleroxacin(FLRX) on the fluorescence of bovine serum albumin(BSA)，zinc(Ⅱ) on that of bovine serum albumin, and zinc(Ⅱ) on the of fleroxacin and bovine serum albumin were studied under imitated the physiological condition. It was shown that both fleroxacin and zinc(Ⅱ) have a powerful ability to quench the BSA fluorescence via a nonradiative energy transfer mechanism. But the fluorescence quenching action of fleroxacin on BSA was much stronger in the presence of zinc(Ⅱ). The fluorescence quenching data were analyzed according to Stern-Volmer equation and double-reciprocal equation, and the binding constant(K) and the binding sites(n) were obtained. In the system of binary complex of FLRX and BSA, K=5.44×104 and n=1.05, while in the system of binary complex of zinc(Ⅱ) and BSA, K=2.19×109 and n=2.
2007 Vol. 27 (04): 765-768 [Abstract] ( 1876 ) PDF (983 KB)  ( 523 )
769 Fluorescence Spectra of Bletilla Striata Aqueous Extraction
SHI Xun-li,WEI Yong-ju*,ZHANG Ying-hua, WANG Ya-min, LIU Cui-ge
Three-dimensional fluorescence spectrum and ultraviolet absorption spectrum of Bletilla striata extraction drawn by boiling water were reported. Three fluorescence peaks, located at λex/λem＝227/299 nm, 271/299 nm and 258/ 389 nm respectively, were observed in the three-dimensional fluorescence spectrum. Among them, the two former peaks having the same emission wavelengths were produced by one fluorescent component, while the latter peak was produced by another. Three-dimensional fluorescence spectrum is a characteristic mark of Bletilla striata, therefore it can be used in qualitative identification. The distance between emission wavelengths of the two components was 90 nm, so the fluorescence intensity of two components couuld be measured separately without pre-separation. For dilute solutions of Bletilla striata aqueous extraction, good linear relationships between fluorescence intensity and concentration of two components were obtained, thereby the quantitative determination of the two components may be carried out. In the range of pH 1.5 to pH 12.5, the fluorescence intensity of the two components changes with the increase in pH, indicating dissociable protons exist in the molecular structure of the two components.

2007 Vol. 27 (04): 769-772 [Abstract] ( 500 ) PDF (1512 KB)  ( 546 )
773 Synthesis，Characterization and Fluorescent Properties of Copper Phthalocyanine Derivates Substituted by Aliphatic Alcohol
ZHANG Liang1,XU Qing-feng1,LU Jian-mei1,2*,YAO She-chun1
A series of copper phthalocyanine derivatives substituted by aliphatic chain were obtained by the reaction of tetra-formyl chloride copper phthalocyanine and aliphatic alcohol such as n-butyl alcohol，n-amyl alcohol，n-hexyl alcohol，n-caprylic alcohol and lauryl alcohol. IR，UV-Vis，elemental analysis and 1H NMR verified the structures and substituting degree. The solubility and the relationship between fluorescence and concentration and substituting group were studied in organic solution. It was confirmed that the solubility in organic solution was improved greatly, the fluorescence did not change in linear according to the concentration and the fluorescence of copper phthalocyanine derivatives substituted by the long alkyl was stronger than that substituted by the relatively short alkyl.
2007 Vol. 27 (04): 773-776 [Abstract] ( 433 ) PDF (1359 KB)  ( 542 )
777 Preparation and Characterization of Magnetic Photocatalysts TiO2/ Fe3O4
SUN Xiu-yun,WANG Lian-jun*,WANG Jian,LI Jian-sheng,LI Xin,WANG Jun-de
Magnetic photocatalysts (TiO2/ Fe3O4), which are liable to be separated and recovered, were prepared using Fe3O4 as the support. The surface morphology and crystal pattern were investigated by means of XRD, SEM, XPS and FTIR. The results showed that TiO2 wraps on the surface of Fe3O4. The photocatalytic activity of the catalysts was investigated by photocatalytic decolorization of (TNR). The photocatalytic activity of the catalysts is high and the separating ratio is good.
2007 Vol. 27 (04): 777-780 [Abstract] ( 420 ) PDF (1456 KB)  ( 510 )
781 Study on the Spectra of Au/α-Fe2O3 Catalysts Modified by ZrO2 and Nb2O5 Promoters
ZHANG Feng-li,ZHENG Qi*,LIN Xing-yi,ZHANG Han-hui,LI Jin-wei,ZHANG Qing
A series of Au/α-Fe2O3 catalysts promoted with ZrO2 and Nb2O5 were prepared by parallel co-precipitation method. Detailed characterizations were conducted by techniques including UV-Vis-DRS, XPS, TEM and XRF. Results indicated that the enrichment of Au, ZrO2 and Nb2O5 on the surface induced by the strong interaction between ZrO2 and Nb2O5 kept the nanoparticles apart, delaying sintering. Performance tests carried out in the reformed methanol steam showed that its CO conversion almost reached the maximum value of 99% at 200 ℃, and maintained a better stability compared with unmodified samples within 50 h on-stream. All these indicated that ZrO2 and Nb2O5 promoters efficiently improved the performance of the Au/α-Fe2O3 catalysts.
2007 Vol. 27 (04): 781-784 [Abstract] ( 416 ) PDF (1064 KB)  ( 586 )
785 Study on a New Method for Determining Trace Amounts of Manganese(Ⅱ) in Water by Flow-Injection Catalytic Kinetic Spectrophotometry
LI Hua1, 2,ZHANG Xin-shen3*,ZOU Yu-quan3,XIE Yong-hong3
An on-line supported flow-injection catalytic kinetic spectrophotometry new method for the determination of trace amounts of manganese(Ⅱ) in water was developed. The method is based on the significant catalytic action of trace manganese on the fading reaction of potassium periodate and magnesonⅠin the presence of nitrilotriacetic acid. The chemical and flow injection variables were optimized. The absorbance intensity was registered in this reaction solution at 560 nm. Under the optimum conditions, a standard curve with good linearity and broad linear range can be obtained in the range of 20-200 μg·L-1,the linear equation is H(mV)＝0.170 5c(μg·L-1)＋0.125 2(r =0.999 3), the detection limit is 1.3μg·L-1,the relative standard deviation is 3.57% (n=8), and the sampling frequency is 15 samples per hour. The interference of foreign iron was studied. Satisfied results were achieved with the proposed method to analyze the Mn(Ⅱ) in river water, waste water and pond water, and the range of recovery was 96%-102%. This method is simple, rapid, sensitive, accurate, highly selective and suitable for automatic and continuous analysis.
2007 Vol. 27 (04): 785-788 [Abstract] ( 1802 ) PDF (1122 KB)  ( 617 )
789 Determination of Trace Mercury and Arsenic in Human Hair of Polymetallic Mining Area by HG-ICP-AES
LI Yong-hua, WANG Li-zhen, WANG Wu-yi, YANG Lin-sheng, LI Hai-rong
In the present paper, a method for the determination of trace elements such as Hg and As in biological samples by HG-ICP-AES was presented. Under the optimum experimental conditions and instrumental operation parameters, both the RSDs of Hg and As with the method were below 3%, and the detection limits were 0.6 ng Hg·mL-1 and 0.8 ng As·mL-1,respectively, satisfying the demand of detecting trace Hg and As concentration in biological samples. Meanwhile, the analytical results of Hg and As in the national standard reference samples such as human hair (GBW 09101), rice (GBW 08503) and tea leaf (GBW 08505) were in good agreement with the certified values, with RSDs around 5%. Using the HG-ICP-AES method, the concentrations of Hg and As in human hair samples of polymetallic mining area in western Hunan province were determined, and the result shows that human in the mining area was exposed to high levels of Hg and As. The concentrations of Hg and As in the mining area were 1.290 and 1.865 μg·g-1 respectively, 3.59 and 2.44 times higher than those in the control area, respectively.
2007 Vol. 27 (04): 789-791 [Abstract] ( 1583 ) PDF (854 KB)  ( 500 )
792 Elimination of Spectral Interference in the Determination of Trace Palladium in Plants by Inductively Coupled Plasma-Mass Spectrometry
ZHU Ruo-hua1,WANG Juan1,SHI Yan-zhi2
Inductively coupled plasma-mass spectrometry (ICP-MS) was employed to determine palladium in plants. The spectroscopic interferences with Pd in the ICP-MS determination were studied in detail. Spectral interferences with Pd were corrected using mathematical correction equation based on abundance ratio. The potential of the method was evaluated by the comparison with the method using complex separation by DDTC and the determination of PGEs (platinum group elements) in standard reference materials (GBW 07293). The experimental results showed that using the studied method, Pd could be determined in the leaves of Japanese pagoda, annual grass, holly and tine tree collected along main roads in Beijing (China) during 2005 with satisfactory.
2007 Vol. 27 (04): 792-795 [Abstract] ( 419 ) PDF (872 KB)  ( 532 )
796 Application of ICP-MS to the Detection of Heavy Metals in Transgenic Corn
RUI Yu-kui1,GUO Jing1,HUANG Kun-lun1, 2,JIN Yin-hua1,LUO Yun-bo1*
With the rapid development of the transgenic food，more and more transgenic food has been pouring into the market，attracting much attention to the transgenic food’s edible safety. Transgenic corns and its parents were studied by ICP-MS to detect the heavy metals. The results showed that the transgenic corn accumulated less heavy metals (Ni, Cu, Cd, As, Cr, Zn and Hg) than their own parents;and the contents of some heavy metals (V, Co and Pb) in transgenic corns were similar to their parents. All the data showed that the insertion of foreign gene (Bt) might change the absorbing dynamics of most heavy metals, especially some important heavy metals, which are disadvantageous to human health. The present paper indicated that the change in heavy metals absorption could harm the edible safety of transgenic plant. The cause of this change should be studied further.
2007 Vol. 27 (04): 796-798 [Abstract] ( 2347 ) PDF (870 KB)  ( 649 )
799 Deviation of Mass Peak Position in Time-of-Flight Mass Spectrum
ZHANG Shu-dong, XU Ming-kun, KONG Xiang-he
Time-of-flight (TOF) mass spectrometer is widely used in many research areas including the study of dynamics of laser ionization/dissociation molecular clusters. A new phenomenon was observed when we used YAG 355 nm laser to ionize water/methanol mixture molecular beam and detect the ions with time-of-flight mass spectrometer: the peak positions of mass ions shift when changing the laser delay time to the molecular beam and keeping other conditions unchanged. The flight time shortens to a minimum value when the laser ionizes the middle part of the molecular beam, while the ions intensity reaches the maximum. The peak shift does not mean a new mass number ion appearing through mass spectra identification. The reason is deduced to be the voltage fluctuation on the extract electrode of TOF when ions pass through the grating electrode and part of them are being absorbed. The numerical simulation of charge-particle movement in electrical field also supports the deduction, and is consistent with the experimental results.
2007 Vol. 27 (04): 799-802 [Abstract] ( 1076 ) PDF (1685 KB)  ( 481 )
803 Enrichment of Triphenyltin in Water Samples by β-Cyclodextrin Cross-Linking Polymer and Determination by Hydride-Generation Atomic Fluorescence Spectrometry
QIU Hai-ou1,YANG Xiao-qiu2,YANG Ming3,XI Yong-qing1,TANG Zhi-yong1
A new method was proposed for the enrichment of triphenyltin in water samples by β-cyclodextrin cross-linking polymer and the quantitative determination of tin in triphenyltin by hydride-generation atomic fluorescence spectrometry. The chemical conditions and instrumental conditions were investigated and optimized. The method is sensitive and precise. The detection limit is 0.1 ng·mL-1 and the RSD 2.64% (for 0.04 μg·mL-1). The proposed method has been successfully applied to the determination of triphenyltin in various water samples.
2007 Vol. 27 (04): 803-806 [Abstract] ( 362 ) PDF (931 KB)  ( 586 )
807 Speciation of Arsenic(Ⅲ) and Arsenic(Ⅴ) in Water by Hydride Generation Atomic Fluorescence Spectrometry
MA Ge1,XIE Wen-bing2*,LIU Jing1,LI Xin-yang1,JIN Yan-wei1
A method for arsenic(Ⅲ) and arsenic(Ⅴ) speciation in water samples using HG-AFS was established. Without any preseparation technique, the speciation was simply accomplished by just adjustment of the acidity for hydride generation. For a sensitive,reproducible and accurate determination, other conditions for hydride generation, such as the concentration of NaBH4 and the added amount of KI as the reductant for arsenic(Ⅴ), were also optimized, and the interference experiment was carried out for concomitant elements. As a result, a detection limit of 0.026 μg·L-1,a relative standard deviation of 2%, and a recovery of 97.5%-103.0% were obtained，indicating the robustness of the method.
2007 Vol. 27 (04): 807-809 [Abstract] ( 1182 ) PDF (845 KB)  ( 609 )
810 Simultaneous Speciation Analysis of Arsenic and Antimony in Traditional Chinese Medicines by Hydride Generation-Double Channel Atomic Fluorescence Spectrometry
YANG Li-li1,LI Na2,ZHANG De-qiang3*
A method is described for the simultaneous determination of As(Ⅲ), As(Ⅴ), Sb(Ⅲ) and Sb(Ⅴ) in traditional Chinese medicines by hydride generation-double channel atomic fluorescence spectrometry(HG-AFS). The experimental conditions that influence the fluorescence intensities of arsenic and antimony were investigated and optimized, and the influence of foreign ions and their elimination were studied. The detection limits were found to be 0.090 3 and 0.057 8 μg·L-1 for arsenic and antimony, respectively. The proposed method was applied to the determination of arsenic and antimony species in traditional Chinese medicines. Recoveries were in the ranges of 90.1%-105.0%, 91.3%-102.0%, 94.7%-109.0% and 98.2%-110.0% for As(Ⅲ), As(Ⅴ), Sb(Ⅲ) and Sb(Ⅴ), respectively.
2007 Vol. 27 (04): 810-812 [Abstract] ( 1179 ) PDF (892 KB)  ( 522 )
813 Determination of Eight Trace Elements in Lanchow Lily by Flame Atomic Absorption Spectrometry
LIANG Bao-an,ZHANG Fu-juan
The contents of eight microelements (Zn, Fe, Cu, Mn, Co, Pb, Cd and Cr) in Lanchow lily were determined by using flame atomic absorption spectrometry with the mixed acid of HNO3-HClO4(3.5∶1) as the digesting solution and the sample of lily being dissolved under the circumstance of normal pressure and little boil. The optimal working conditions of the instruments used to determine the different elements were studied. The proper sample digestion system was determined. The disturbance, accuracy and precision of the method were examined. The elements in lily did not interfere with each other under the given experimental condition, so the authors can examine the eight elements in the same preparation solution. The experimental result indicates that there are abundant Zn, Fe, Cu and Mn in the Lanchow lily, but there are no harmful elements Pb and Cd. The recovery and relative standard deviations are 94.20%-111.20% and 2.45%(n=6), respectively. The result is accurate and reliable.
2007 Vol. 27 (04): 813-815 [Abstract] ( 368 ) PDF (893 KB)  ( 580 )
816 A New Method for the Measurement of Degrees of Reduction and Metallization of Iron Oxide
GUO Pei-min,ZHANG Dian-wei,ZHAO Pei
Quantitative analyses of mixture composed of iron oxides and metal iron were investigated by means of powder X-ray diffraction and chemical analysis methods for iron oxides reduction by H2 and CO, respectively. The coefficients of quantitative molar intensity ratio of ferrite (αFe), austenite (γFe), iron carbide (Fe3C), magnetite(Fe3O4) and hematite (Fe2O3) to wustite (Fe0.947O) are 0.56, 0.56, 0.52, 0.87 and 2.57 respectively. The degrees of metallization and reduction of iron oxide were calculated according to these coefficients.
2007 Vol. 27 (04): 816-818 [Abstract] ( 668 ) PDF (1135 KB)  ( 588 )
819 Damage Analyse of X-Ray Radiated Cellobiohydrolase Ⅱ Molecule from Trichoderma Viride
YU Duo-wei, YUAN Sheng
After X-ray treatment at 1.82 keV and 40 mA and 4 hours, the cellobiohydrolase Ⅱ(CBHⅡ) aqueous solution of Trichoderma viride was analysed, and the damage state of the irradiated molecule was detected using some cysteine residue relative parameters in Raman spectroscopic methods. The results show that S—H stretch modes of CBHⅡ exhibited some shift, which means that the hydrogen proton donor state of sulfhydryl groups was stronger and weaker, respectively. The 2 554 cm-1 peak of irradiated sample was wide. The —S—S— construction of disulfide bonds was not broken, and the geometrical conformation types did not change either, but its bond length was somewhat shortened. Before irradiation, C—S isomer mode content of cysteine residue was PC type slightly more than both PN and PH types, while PN and PH types increased after irradiation. Besides, CH2 rocking mode of cysteine residue was weakened remarkably after the treatement, and the protein molecule structure did not show important damage in sulfhydryl and disulfide bonds, but showed some change because of the X-ray irradiation condition.
2007 Vol. 27 (04): 819-822 [Abstract] ( 390 ) PDF (1298 KB)  ( 442 )
823 Hardening Correction Model of Energy Spectrum for X-Ray TICT in Testing Composites Workpiece
PENG Guang-han1, 2,YANG Xue-heng3,CAI Xin-hua1,QIAO Nao-sheng1,LIU Chang-qing1
In the case of a polychromatic source in X-ray TICT, the variation of attenuation coefficient with energy leads to low energy radiation being absorbed preferentially. In other words, the higher the energy, the lower the attenuation coefficient. With the transmission thickness augmenting, it is easier for X-ray to transmit the matter. The phenomenon is energy spectrum hardening. Thus, hardening correction has to be done. In the present paper, not only is energy spectrum hardening analyzed by theory and the relation stated between attenuation coefficient and transmission thickness in testing composites workpiece, but also the precise accurate theory model for hardening correction of energy spectrum and theory method are reasoned out in testing composites workpiece, which results from Beer′s law and the characteristics of X-ray interaction with composites. Then, the attenuation coefficient that has been corrected is used for product back-projection reconstruction. Thus, the effect caused by X-ray beam hardening is wipped out effectively in testing composites workpiece.
2007 Vol. 27 (04): 823-826 [Abstract] ( 379 ) PDF (955 KB)  ( 407 )
827 Determination of Constituents of Polysaccharide and Contents of Saccharide from Mongolian Medicine Agari-8
ZHAO Yu-ying1,SONG Juan-juan1,ZHAO Yu-qin2,XU Xiu-ting1, HAI Ping1
The water soluble polysaccharide was extracted from Agari-8, and the contents of the water soluble polysaccharide were determined by phenyl hydrate-sulfuric acid method. The average recovery was 101.80%. The RSD was 0.92%. The components of the water soluble polysaccharide were identified by gas chromatography with: arabinose, xylose, mannose and glucose in the molar ratio of 0.40∶0.10∶5.67∶22.78. Their IR and UV spectra were studied.
2007 Vol. 27 (04): 827-829 [Abstract] ( 384 ) PDF (1061 KB)  ( 587 )

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