■ 加入收藏　 ■ 设为首页
 
Home　|　中文  
　　 Home   |   About Journal   |   Editorial Board   |   Instruction   |   Rewarded   |   Indexed-in   |   Impect Factor   |   Subscriptions   |   Contacts Us
News

ScholarOne Manuscripts Log In

User ID:

Password:

Forgot your password?

Enter your e-mail address to receive an
e-mail with your account information.
  Journal Online
    Current Issue
    Advanced Search
    Archive
    Read Articles
    Download Articles
    Email Alert
    
Links  
22 CAST
22 CNCOS
22 CNKI
22 WanfangDATA
22 CHEMSOC
22 sinospectroscopy
22 CPS
Quick Search  
  Adv Search
2005 Vol. 25, No. 06
Published: 2005-06-26
 
       光谱学与光谱分析
801 Atomic Hydrogen Emission Line and the High Quality Diamond Film
SHANG Yong，DONG Li-fang*，WANG Zhi-jun
The process of atomic hydrogen emission in CH4/H2 gas mixture in EACVD is simulated by Monte Carlo method. In the simulation two basic types of collision between electron and H2 molecule are considered: elastic collision and inelastic collision. Four types of inelastic processes have been considered, namely vibrational excitation, dissociation, electron excitation (contains Hα, Hβ and Hγ) and ionization. For e-CH4 collision, elastic momentum transfer, vibrational excitation, dissociation, dissociative excitation (contains Hα, Hβ and Hγ), ionization and dissociative ionization are considered. The relationship between the number of H, CH3 and the ratio of atomic hydrogen emission line intensity under different experimental conditions is investigated. A method to obtain the optimum experimental condition for diamond deposition by the atomic hydrogen emission line is given. The result is of great importance to depositing high quality diamond films by controlling the conditions of technology efficiently.
2005 Vol. 25 (06): 801-803 [Abstract] ( 946 ) PDF (378 KB)  ( 340 )
804 Study on the Growth and Spectral Characteristics of Cr3+:Al2(WO4)3 Crystal
TU Chao-yang, ZHU Zhao-jie, LI Jian-fu, WANG Yan, YOU Zhen-yu, WU Bai-chang
Cr3+:Al2(WO4)3 Crystal was grown from the Na2WO4 solvent system by using the TSSG method. The absorption spectrum shows that there are two strong absorption wideband peaks and one weak absorption peak belonging to Cr3+ ion in the crystal. The peak values of two strong absorption wideband peaks are at 422 and 595 nm, respectively. The values of two weak absorption peaks are at 684 and 663 nm, respectively. The fluorescence spectrum shows that one emission wideband peak ranging from 650 to 820 nm coexists with one stronger emission peak at 680 nm. The peak value of emission wideband is at 740 nm. The crystal field and Racah parameters were calculated, where Dq/B=2.420 indicates that it has an intermediary crystal field. The result shows that Cr3+:Al2(WO4)3 crystal is promising for tunable laser because it not only has the spectral characteristics required for tunable laser crystal but also has the good physicochemical properties.
2005 Vol. 25 (06): 804-807 [Abstract] ( 1076 ) PDF (371 KB)  ( 363 )
808 The Effect of Doppler Effect on Ultraviolet Absorption Spectrum from Difference in Temperature (UVASDT)
HU Yao-gai1, 2, ZENG Fan-qing2, LI Wei1, HU Ji-ming1*
In this paper, the formation of UV absorption spectrum from difference in temperature (UVASDT) is discussed. Broadening of spectral lines might be one of the reasons for the formation of UVASDT. The effect of temperature on the broadening of spectral lines is analyzed. The Doppler SDT function is deduced, and the SDT of C60 and progesterone can be explained by it. It is indicated that the Doppler effect might be the primary reason for the formation of UVASDT of this kind of substance.
2005 Vol. 25 (06): 808-810 [Abstract] ( 1721 ) PDF (333 KB)  ( 326 )
811 Study of PVK:TPB Thin Film by Using Stable Spectra
SUN Shi-ju, TENG Feng*, XU Zheng, ZHANG Yan-fen, HOU Yan-bing
The energy transfer between PVK and TPB in PVK:TPB thin film in different concentrations was studied by emission spectra, excitation spectra, and absorption spectra. It is proved that the energy can be transfered from PVK to TPB in a wide concentration range and the transfer is most efficient at the concentration of 5% wt. A model Hamitonian based on a single chain model including the dopant was proposed to simulate the experiment. This model can be used to explain the experimental results very well.
2005 Vol. 25 (06): 811-814 [Abstract] ( 993 ) PDF (450 KB)  ( 326 )
815 Effects of Chemical Sensitization on Photoelectron Time-Resolved Spectrum
LI Xiao-wei, LI Xin-zheng, LAI Wei-dong, JIANG Xiao-li, TIAN Xiao-dong, YANG Shao-peng, FU Guang-sheng
The time-resolved spectra of free photoelectrons and shallow-trapped electrons in the T-grains AgBrI emulsion were simultaneously detected with microwave absorption and dielectric spectrum detection technique. The results indicate that the electron trap effects of sulfur sensitization centers and sulfur-plus-gold sensitization centers are different with equal quantities of Na2S2O3 added. The sulfur sensitization centers acted as a deep electron trap to pick up the electronic decay because of increasing the number of deep trapped electrons, while the sulfur-plus-gold sensitization centers as a shallow electron trap decrease the electronic decay through effectively controlling the recombination between the electrons and the holes. The depth of sulfur-plus-gold sensitization center is shallower than that of sulfur sensitization center after the KAuCl4 is added. The effects of sulfur sensitization center and sulfur-plus-gold sensitization center on the photoelectron decay are different in different sections of decay curves through the change in electron time-resolved spectra.
2005 Vol. 25 (06): 815-818 [Abstract] ( 1917 ) PDF (372 KB)  ( 342 )
819 Upconversion Luminescence Properties of YLiF4:Er，Tm，Yb Synthesized by Hydrothermal Method
PEI Xiao-jiang，HOU Yan-bing，XU Zheng, ZHAO Su-ling，TENG Feng
YLiF4 codoped with Er3+，Tm3+and Yb3+ ions was synthesized by hydrothermal method. The absorption spectra and upconversion spectra excited at 980 nm were investigated. Under the excitation of infrared photons，strong white emission can be obtained. According to the value of n obtained from the power law，the 484 nm blue emission，524 and 552 nm green emission, and 665 nm red emission are all due to two photon process，while the UV emission is attributed to three photon process. The authors also analyzed the upconversion mechanism and process.
2005 Vol. 25 (06): 819-823 [Abstract] ( 1106 ) PDF (633 KB)  ( 351 )
824 Study on Red Up-Conversion Luminescence of Fluoride Glasses Doped with Er3+, Yb3+ and Tm3+
YAN Lei, LIU Zheng-wei,YANG Xiao-liang
When the quality of Er2O3 is 10 times the former, the authors found that its character of up-conversion luminescence is distinct. Then the authors studied the luminescence system of Es3+／Tm3+，Er3+／Er3+ and Er3+／Yb3+／Tm3+ and their character of up-conversion and fluorescence spectrum at 980 nm. In addition, the authors studied the relation between the three systems and the consistency of Er2O3. The authors found that the intensity of green and red light changed with the consistence of Er3+ in the experiment. It’s the consistence of Er3+ that is the most causative. The chance is equal for each lanthanonion that makes up the luminescence system in the uniformity matter. With the distance between each pair of lanthanonions in the luminescence system is changed, the luminescence system and the color of the up-conversion luminescence also changed.
2005 Vol. 25 (06): 824-827 [Abstract] ( 1089 ) PDF (404 KB)  ( 376 )
828 Luminescence Properties of Rare Earth Complexes Tb(BSA)4
LIN Peng, LIANG Chun-jun, DENG Zhen-bo, BAI Feng , ZHANG Zhi-feng, XIONG De-ping, ZHANG Xi-qing
A new rare earth complex Tb(BSA)4 was synthesized and studied. Pure green and narrow band emission was generated from the device with structure ITO/PVK:Tb(BSA)4/Alq3/LiF/Al, where PVK was used to improve the film-formation and hole-transport property of the Tb(BSA)4. The absorption mechanism, and the photoluminescence and electroluminescence mechanisms are discussed. It has been proved that there exists energy transfer from PVK to Tb(BSA)4 and the mechanisms of photoluminescence and electroluminescence are different. The effect of different ratios of PVK on the device characteristics is also studied.
2005 Vol. 25 (06): 828-831 [Abstract] ( 1093 ) PDF (492 KB)  ( 381 )
832 Preparation of Anodic Al2O3 Films on SiO2 Substrate and Their Photoluminescence Properties
XIONG De-ping, ZHANG Xi-qing, LIN Peng, WANG Li
300 nm thick aluminum films were deposited on SiO2 substrates by heat evaporation. At 0 ℃, 40 V DC voltage, the authors successfully prepared high density Al2O3 films by anodic oxidation on SiO2 substrates with 15 wt% H2SO4 as electrolyte, and AFM was employed to study the film surface morphology． At room temperature the authors measured the photoluminescence spectrum of Al2O3 films prepared at different anodic voltages excited by Xe lamp. In addition, the authors monitored their excitation spectra of different emission peaks, and the authors found that the relative emission intensity gets weaker and shifts to lower energy at higher anodic voltage. At 40 V anodic voltage the authors observed new 356 nm ultraviolet emission, which has the same 210 nm excitation emission. Based on the discussion of the relative intensity of the PL spectra of anodic alumina at different voltages, the authors suggest that F and F+ oxygen vacancy defects were responsible for the observed 356 and 386 nm ultraviolet photoluminescence from Al2O3 anodic film at 40 V voltage.
2005 Vol. 25 (06): 832-835 [Abstract] ( 932 ) PDF (538 KB)  ( 301 )
836 Electroluminescent Device Based on Rare Earth Terbium Complex
ZHANG Meng-xin1, DENG Zhen-bo1*, BAI Feng1, ZHANG Zhi-feng1, XU Deng-hui1, LIANG Chun-jun1,WANG Rui-fen2
Rare earth complex TbY(m-MBA)6(phen)2·2H2O have been synthesized, which were used as emitting materials in electroluminescence. Single-layer devices and bilayer devices with Alq as electron transmission layer have been fabricated. The electroluminescent properties of the devices were studied. The electroluminescent mechanism of the devices was proposed by measuring and analyzing the emission and the excitation spectra of the emissive layer. Y3+ may play the role to promote the energy transfer from ligand to Tb3+ and the possible energy transfer process of the device was preliminarily discussed.
2005 Vol. 25 (06): 836-839 [Abstract] ( 1473 ) PDF (427 KB)  ( 356 )
840 Preparation and Luminescence of CeOx/ZnO Nanocomposite Powders
GUO Shu-xia, ZHANG Xing-tang, ZHAO Hui-ling, LI Yun-cai, HUANG Ya-bin,DU Zu-liang*
CeOx/ZnO nanocomposite powders were prepared by sol-gel process. The powder samples were examined by XRD，TEM，XPS and photoluminescence (PL). PL enhancement of nanocomposite powder at 502 nm compared to pure ZnO was observed when Ce3+ were present in samples. New peak at 603 nm was observed when Ce4+ were present. PL enhancement of nanocomposite powder was correlated with more oxygen vacancies which were caused by Ce3+. Ｔhe new peak at 603 nm is attributed to new energy transition in the interface of CeO2/ZnO.
2005 Vol. 25 (06): 840-843 [Abstract] ( 1577 ) PDF (443 KB)  ( 313 )
844 Determination of 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-Glucoside in the Traditional Chinese Preparation by High Performance Liquid Chromatography with Chemiluminescence Detection
WEI Hong-qing1，2, LIU Er-bao1*, REN Rong-fang1, ZHAO Xiu-li2，LI Xiao-xia2, JIANG Feng-xian2
Based on the chemiluminescence reaction of KMnO4-HNO3-2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside sensitized by HCHO, an analytical method for 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside by RP-HPLC with chemiluminescence detector was developed. The chromatographic conditions were optimized. AN ODS hypersil column(25 mm×4.0 mm, 125×4.0 mm i.d. 5 μm) was used with acetonitrile-0.3% H3PO4[25∶75, (φ)] as mobile phase, and the flow rate was 0.8 mL·min-1 at the column temperature of 40 ℃. The linear range of calibration curve was from 15.75 to 136.5 μg·mL-1, the detection limit was 11.83 μg·mL-1 with a concentration of 21 μg·mL-1 of 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside, and the recovery was 102%-108%. The relative standard deviation was 3.45%(Cs=21.0 μg·mL-1, n=3). The method has been applied to the determination of 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside in a few Chinese medicines, and the results were satisfactory. The method was simple, rapid and highly selective.
2005 Vol. 25 (06): 844-847 [Abstract] ( 1523 ) PDF (476 KB)  ( 356 )
848 Photoluminescence of One Dimension ZnO Single Crystal Columns Array Excited by Different Space Variation Direction
XIE Ping-bo1, 2, ZHAO Fu-li2, LI Ya-dong3, GONG Zhen2, WANG He-zhou2
Highly-oriented single crystal ZnO columns array was prepared by a simple two-step evaporation oxidation method. And the photoluminescence properties of different direction excitation were investigated. Upon different direction excitation, the emission spectra were greatly different. Besides the relative intensity of different emission peak of PL changed; some new emission peaks were also detected at high excitation power. This showed that the energy absorption, transmission and emission in one dimension ZnO column array were directional. The up-conversion polarized photoluminescence spectra were also found, and the intensities of 400 nm emission peak were affected by the laser polarization orientation. These results showed that the intensity and shape of PL were related with the direction and polarization of the excitation laser. The results also give some important references for subminiature one dimension line array optoelectric device.
2005 Vol. 25 (06): 848-853 [Abstract] ( 1631 ) PDF (772 KB)  ( 393 )
854 The 440-495 nm Laser-Induced Fluorescence Excitation Spectrum of NO2
ZHANG Gui-yin1,2，ZHANG Lian-shui1，SUN Bo1，HAN Xiao-feng1
Under the conditions of room temperature and low pressure, laser-induced fluorescence excitation spectrum of NO2 in the wavelength region of 440-495 nm was obtained by using optical parameter generator (OPG) and amplifier (OPA) as an excitation source. The OPG/OPA was pumped by a Nd:YAG laser. The peaks of the spectrum are attributed to B2B1←X2A1 transition. The angle-vibration frequency of B2B1 electronic state was calculated. The fluorescence lifetime of B2B1 (0, 9, 0) vibration state under the pressure of 15 Pa was also deduced by measuring the fluorescence time decay spectrum of this state. It is about 49 μs. Fitting the curve of the fluorescence radiant lifetime versus pressure, the spontaneous radiant lifetimes τ0 and the rate coefficient kq of non-radiant transition relaxation of B2B1 (0, 9, 0) state are deduced. The results are: τ0≈55 μs and kq=1.2×10-9 cm3 molecule-1s-1.
2005 Vol. 25 (06): 854-856 [Abstract] ( 1056 ) PDF (385 KB)  ( 336 )
857 Synthesis of Substituted 3H-Indole Quaternary Ammonium Salt and Study on Its Interaction with Bovine Serum Albumin by Fluorescence
XU Tong-kuan, SHEN Xing-hai*, GAO Hong-cheng
A substituted 3H-indole quaternary ammonium molecule was designed and synthesized using hexamethylphosphoramide (HMPA) as a solvent. The products were purified and characterized by IR, 1H-NMR, MS and elemental analysis. The binding reaction of this compound with bovine serum albumin (BSA) in aqueous solution was studied using fluorescence. Their binding constant is Ka=1.995×105 dm3·mol-1 and the binding site number is n=1.12. It is confirmed that the combination is a single static quenching process.
2005 Vol. 25 (06): 857-860 [Abstract] ( 1080 ) PDF (449 KB)  ( 334 )
861 Simultaneous Measurement of Muscle Energy Metabolism by MRS and Frequency-Domain NIR Spectroscopy
ZHAO Jun1, DING Hai-shu1*, RUAN Man-qi1, KIME R2, CHANCE B2
The frequency-domain near-infrared spectrometry(NIRS) is capable of measuring the absolute absorption and reduced scattering coefficient of tissue noninvasively. This allows the quantitation of tissue hemoglobin concentration which reflects the balance between oxygen delivery and oxygen utilization of the skeletal muscle. Phosphorus magnetic resonance spectroscopy (31P-MRS) has become a gold standard of noninvasive measurement of human skeletal muscle metabolism. The rate of phosphocreatine (PCr) resynthesis during recovery is an indicator of the rate of oxidative metabolism. The purpose of the present study was the effect of lower intracellular pH (pHi) on PCr and oxygenation recovery. The preliminary results of plantar flexion experiment on a healthy male subject show that both PCr resynthesis and reoxygenation were very much prolonged by severe acidosis (pHi=6.42).
2005 Vol. 25 (06): 861-865 [Abstract] ( 1032 ) PDF (610 KB)  ( 338 )
866 The Study of Phosphorus in Seawater Cultured Pearls Using FTIR
WANG Li-hua1，2，ZHOU Pei-ling2，LIU Yan3，TANG Yun-hui4
Seawater cultured pearl was studied by high resolution fourier transform infrared spectroscopy (FTIR) both before and after having been heated at 160 centigrade degree. The results of FTIR indicate that the main material in both samples is aragonite(CaCO3). But compared with the spectra of the seawater cultured pearl, there are some changes that happen in that of the heated sample. Some other peaks arise in the latter. And the intensities of these peaks increase with the heating time. Differential Thermal Analysis (DTA) curve of the seawater cultured pearl shows that seawater cultured pearl has no change between 25-160 ℃ except absorbed water evaporating from the sample. All these evidences prove that besides aragonite, there exists something else in the seawater cultured pearl. This component was determined to be pahuite by FTIR spectroscopic analysis. X-Ray Diffraction (XRD) analysis of the same sample came to the same conclusion.
2005 Vol. 25 (06): 866-869 [Abstract] ( 1813 ) PDF (419 KB)  ( 359 )
870 Application of FTIR Technique in Microwave-Hydrothermal Synthesis of Saponite
YAO Ming1, 2, LIU Zi-yang2, WANG Kai-xiong1, ZHU Miao-qin2，SUN Hong-jie2
FTIR was employed in the structure analysis of the saponites with an ideal chemical formula[Si6.5Al1.5]Ⅳ[Mg6]ⅥO20(OH)4 in the starting gel synthesized by microwave-hydrothermally under different pressures (1×105, 5×105, 1.5×106, 2.5 ×106 and 3.5×106 Pa). It was found that low frequency absorption region in infrared spectrum was sensitive to the crystallization of the product and the amorphous materials produced in synthesis of saponite under the radiation of microwave. The absorptions belong to amorphous materials were decreased with increasing pressure. Saponite synthesized at 3.5×106 Pa showed no amorphous absorptions (1 240, 590-602 cm-1), indicating the purity and quality of the synthetic mineral. It was worthy to note that Si(Al)—O stretching vibration infrared absorption could be regarded as an index in assessing the quality of synthetic 2∶1 trioctahedral smectite sample with the same chemical compositions. With the increasing pressure, this strong vibration shifted to low frequency (1 022, 1 020, 1 016, 1 016, 1005 cm-1) in the medium frequency of the whole infrared spectrum. Since the sensitivity, easiness and simplicity, this infrared index would be meaningful in practical saponite-related minerals analysis. In addition, powder X-ray diffraction and scanning electronic microscopy were employed in charactering the saponite synthesized by microwave-hydrothermal method in this work.
2005 Vol. 25 (06): 870-873 [Abstract] ( 1120 ) PDF (499 KB)  ( 354 )
874 Radial Basis Function Networks and IR Spectrometry Applied for Identification of Official Rhubarb Samples
MA Shu-min1, LIU Si-dong1, ZHANG Zhuo-yong2*, FAN Guo-qiang3
The Fourier transform infrared spectrometry (FTIRS) and radial basis function neural network (RBF-NN) have been applied to develop classification models for identifying official and unofficial rhubarb samples. The original data were compressed from 775 variables to 49 variables by using wavelet transformation method. The compressed spectra with reduced variables maintain the characteristics of the IR spectra and speed up the network training process. The effects of network parameters including error goal and spread constant, were investigated. The rate of correct classification is up to 97.78% at optimized conditions. Results show that the combination of IRS and ANN can be used as fast and convenient tool for identification of Chinese herbal samples.
2005 Vol. 25 (06): 874-877 [Abstract] ( 1519 ) PDF (451 KB)  ( 355 )
878 Use of FTIR and Pattern Recognition to Determine Geographical Origins of Chinese Medical Herbs
LIU Shu-hua1, ZHANG Xue-gong1*, ZHOU Qun2，SUN Su-qin2
Geographical origin of medical herbs is an important factor of the quality of many traditional Chinese herbal medicines. The objective of this study is to investigate whether FTIR spectroscopy coupled with pattern recognition techniques could effectively discriminate geographical origins of medical herbs. Nearest neighbor method (NNM) and a SVM-based multiclass classifier were employed to discriminate 269 angelicae dahuricae radix (ADR) samples from 4 provinces in China and 380 salviae miltiorrhizae radix (SMR) samples from 6 provinces. A leave-one-out cross-validation accuracy of 99% was achieved by the multiclass classifier. The study shows this classification scheme can be a highly accurate approach for the discrimination of medical herbs of different origins.
2005 Vol. 25 (06): 878-881 [Abstract] ( 1017 ) PDF (476 KB)  ( 348 )
882 Achievement of the Noninvasive Measurement for Human Blood Glucose with NIR Diffusion Reflectance Spectrum Method
ZHANG Hong-yan1, DING Dong2, SONG Li-qiang3, GU Lin-na1, YANG Peng1, TANG Yu-guo1
The noninvasive measurement of human blood glucose was achieved with NIR diffusion reflectance spectrum method. The thumb fingertip NIR diffusion reflectance spectra of six different age healthy volunteers were collected using Nexus-870 and its NIR fiber port smart accessory. The test was implemented with changing the blood glucose concentration for the limosis and satiation of every volunteer. The calibration model was set up using PLS method with the smoothing, baseline correction and first derivatives pretreatment spectrum in the 7 500-8 500 cm-1 region for single volunteer, the same age combination and that of different age. When the spectrum was obtained, the actual blood glucose value of every spectrum sample was demarcated using ultraviolet spectrophotometer. The correlation between the calibration value and true value for single volunteer is better than that for the combination of volunteers, the correlative coefficients are all over 0.904 71, RMSECs are all less than 0.171.
2005 Vol. 25 (06): 882-885 [Abstract] ( 1110 ) PDF (427 KB)  ( 359 )
886 Effects of the Accuracy of Reference Data on NIR Prediction Results
CHU Xiao-li，YUAN Hong-fu，LU Wan-zhen
Reference data are indispensable to build near-infrared spectroscopy (NIR)calibration models. In the present paper, the effects of the accuracy of reference data on NIR calibration models and its prediction results were studied through two routine applications based on partial least square regression methods. The results indicate that the best NIR calibration statistics and the most accurate prediction results were aligned with the most accurate reference data. However, based on statistical analysis of numerous calibration samples, it is possible for NIR calibration models to obtain more accurate prediction results than the laboratory reference data used in the calibration sets. It is better to make less search for high accurate reference data and instead to introduce more calibration samples to improve the ruggedness of the calibration models.
2005 Vol. 25 (06): 886-889 [Abstract] ( 345 ) PDF (458 KB)  ( 401 )
890 Study on Temperature Correctional Models of Quantitative Analysis with Near Infrared Spectroscopy
ZHANG Jun1, CHEN Hua-cai1, 2, CHEN Xing-dan1
Effect of enviroment temperature on near infrared spectroscopic quantitative analysis was studied. The temperature correction model was calibrated with 45 wheat samples at different environment temperaturs and with the temperature as an external variable. The constant temperature model was calibated with 45 wheat samples at the same temperature. The predicted results of two models for the protein contents of wheat samples at different temperatures were compared. The results showed that the mean standard error of prediction (SEP) of the temperature correction model was 0.333, but the SEP of constant temperature (22 ℃) model increased as the temperature difference enlarged, and the SEP is up to 0.602 when using this model at 4 ℃. It was suggested that the temperature correctiona model improves the analysis precision.
2005 Vol. 25 (06): 890-893 [Abstract] ( 1028 ) PDF (424 KB)  ( 383 )
894 The Study of Feature Extraction of Near-Infrared Spectroscopy with Multi-Scale Edge Extraction Method
LIU Qing-ge1, LI Shu-jian1, LI Xue-shan2
The authors utilized a multi-scale edge extraction method to extract feature information of nearinfrared spectroscopy. Applying partial least-squares to characteristic data obtained, the authors set up a linear mathematical model of the correlation between NIR spectrum and metronidazole contents. The result shows that the multi-scale extraction method can separate and extract feature information, and can be seen as an effective method of spectrum information extraction. The present study offers a new solution to the problems in nearinfrared spectroscopy technology.
2005 Vol. 25 (06): 894-897 [Abstract] ( 1169 ) PDF (443 KB)  ( 363 )
898 A New Linear Neural Network Multi-Component Analysis Method and Its Application in the Analysis of VC Yinqiao Tablets Quantitative Analysis
BAI Ying-kui1, SHEN Xuan-guo2, FENG Yi2, ZHANG Tie-qiang2, HUANG Fang2
We measured NIR spectrum of VC Yinqiao tablets with spectral instrument, analyzed the contents of acetaminophen and vitamin C in the VC Yinqiao tablets with principal component analysis(PCA) and Linear Neural Network, and discussed the choice of principal component number and ANN’s parameters affecting the network . To compare arithmetic performance, the authors also processed the spectral data with partial least squares and PCA-BP neural network. Compared with other two data process methods, the experiment and the result of data process showed that the PCA-linear neural network possess the best forecasting precision.
2005 Vol. 25 (06): 898-901 [Abstract] ( 391 ) PDF (448 KB)  ( 397 )
902 Applications of Moissanite Anvil Cell for Raman Spectroscopy under High-Temperature and High-Pressure
DUAN Ti-yu1,2，SUN Qiang1，ZHENG Hai-fei1*
This paper introduces the structure and the feature of moissanite anvil cell, which is composed of moissanite anvil, supporting and creating pressure system, heater system and metal gasket. Because of its high hardness, high heat conductance, low thermal expansion, good thermal stability and low price, moissanite is a good material of anvil for high-temperature and high-pressure experimental studies. With this cell, the Raman spectrum of sodium carbonate solution, sodium sulfate solution and distilled water has been in situ measured under high-temperature and high-pressure. With increasing pressure, it can be observed that the 1 066 cm-1 Raman modes of sodium carbonate solution and the 982 cm-1 Raman modes of sodium sulfate solution shift to high wave numbers obviously. With increasing temperature, the frequency at maximum intensity shifts to high wave numbers, the full width at half-maximum intensity decreases in the Raman spectrum of water.
2005 Vol. 25 (06): 902-905 [Abstract] ( 254 ) PDF (467 KB)  ( 390 )
906 Theoretical Calculation of Vibrational Frequencies for Clusters of (1，2-μ2-L1)(1，2-μ2-L2)-Decacarbonyltriosmium [L1，L2=H，Cl，Br，I]
ZENG Rong-ying1，KUANG Dai-zhi1，YI Xiang-hui2，HOU Ruo-bing2
Density functional theory(DFT) and ab initio method have been employed to optimize the molecular geometry of (1，2-μ2-H)(1，2-μ2-L)Os3(CO)10(L：Cl，Br，I)at B3LYP/CEP-4G, B3LYP/LanL2DZ, RHF/CEP-4G and RHF/LanL2DZ levels，respectively. By using ab initio method，the authors have optimized the molecular geometry of (1，2-μ2-L)2Os3(CO)10(L：H，Cl，Br，I). The calculations showed that the charge was translated from Os(CO)3 to Os(CO)4. Harmonic vibrational analysis was performed at the RHF/CEP-4G levels，and according to the frequencies and intensities of the equilibrium structure obtained by using ab initio method，the IR spectra of structure have been simulated. The calculated results were compared with each other and with available experimental data，and were discussed in detail.
2005 Vol. 25 (06): 906-911 [Abstract] ( 1108 ) PDF (645 KB)  ( 343 )
912 The Interaction of Vitamin B6 with the Human Serum Albumin
WANG Jian-lin2, FU Lian-chun3, ZHOU Shi-wu4, CHEN Zhi-jian1, Lü Wen-bo1, YE Xue-min1, MENG Guang-zheng5, SONG Zeng-fu1*
The Human Serum Albumin(HSA)can emit fluorescence(λem=350 nm)under irradiation of ultraviolet light(λex=296 nm). After the vitamin B6(B6)was added into HSA solution the fluorescence of HSA was quenched partially. This quenching was static quenching owing to the fact that τ０(fluorescence life time (life time of the molecule excitation state) of HSA without B6) equaled to τi(fluorescence life time of HSA with B6). The formation constant K between HSA and B6 was observed from the experiment, and then the binding distance R０ was determined(R０=1.872 nm). The CD spectra of samples (HSA，=1×10-5 mol·L-1，HSA+B6，[B6]=5×10-8，1.5×10-7，2.5×10-7，3.5×10-7，4.5×10-7 mol·L-1) were measured, and all CD spectra were almost the same. From [θ]values, the contents(percent content)of four structure(α-Helix，β-Pleated，β-corner，and Randon wind)of samples can be calculated, and we find that all samples contain almost the same structure contents.
2005 Vol. 25 (06): 912-915 [Abstract] ( 1762 ) PDF (413 KB)  ( 384 )
916 Simulation of the Medium Dielectric Constant Dependent Optical Properties for Gold Nanorods
ZHU Jian, WANG Yong-chang
Suspended gold nanorods were synthesized via electrochemical method. UV-Visible spectra and fluorescence emission spectra were measured at room temperature. Numerical calculations based on quasi-static and scattering theories were developed to describe these observed optical properties. Because of the anisotropy of the gold nanorods, both absorption features and scattering features show two peaks, which result from the transverse and longitudinal surface plasmon resonances respectively. Furthermore, with increasing the dielectric constant of surrounding medium from 1.5 to 2.5, these two absorption peaks increase and red shift in a nonlinear way together. However, the scattering peak at the shorter wavelength depends on the surrounding medium dielectric constant in a linear fashion, and the other scattering peak at the longer wavelength decreases and red shifts nonlinearly.
2005 Vol. 25 (06): 916-919 [Abstract] ( 1062 ) PDF (501 KB)  ( 315 )
920 Effect of Cation Surfactants on Absorption Spectra of Silver Nanoparticle in Liquid Phase
YUAN Wei-en，JIANG Zhi-liang*，PAN Hong-cheng，KANG Cai-yan
Yellow Ag nanoparticles, with diameter of 20 nm, exhibit a resonance absorption peak at 400 nm. After adding some cation surfactants (CS), the absorbance at 400 nm becomes weak, (namely, there exists hypochromic effect), but the absorbance at wavelengths longer than 400 nm is enhanced and shows a red shift. When adding concentration of CS, the absorbance at wavelengths longer than 400 nm becomes weak again, the peak at 400 nm is enhanced (namely, there exists hyperchromic effect) and the absorption peaks show a blue shift. The results showed that this is caused by the strong hydrophobic force and electrostatic force between the CS and silver nanoparticls, which results in a change in the silver nanoparticle shape.
2005 Vol. 25 (06): 920-922 [Abstract] ( 403 ) PDF (353 KB)  ( 359 )
923 The UV-Vis Spectra and Substituent Effect of Organoimido Derivatives of Polyoxometalates
LI Qiang1, 3, WEI Yong-ge2, WANG Yuan2,GUO Hong-you1*
In the presence of a carbodiimine, i.e. DCC, a series of organoimido derivatives of polyoxometalates have been synthesized via the reaction of [α-Mo8O26]4- with aromatic amines and its hydrochloride salt. Elemental analysis, IR, 1H-NMR and UV-Vis spectra were used to characterize those hybrids, in particular their UV-Vis spectra have been studied. The results show that typical metal-ligand charge transfer (MLCT) transitions occur in the organic-inorganic hybrid molecules. There is a good linear relationship between the shift of UV-Vis absorptions(Δλmax) and conjugation effect of the p-substituted group (σR).
2005 Vol. 25 (06): 923-926 [Abstract] ( 1141 ) PDF (428 KB)  ( 350 )
927 Microdetermination of Proteins with Titan Yellow by the Resonance Light Scattering Method
FENG Su-ling, WANG Jin, FAN Jing
A resonance light scattering method for the determination of trace proteins was developed. In the presence of Triton X-100, proteins reacted with Titan yellow to form a combination product, resulting a significant enhancement of resonance light scattering(RLS). The ΔIRLS was directly proportional to the concentration of protein in the range of 0.03-0.9 μg·mL-1, with the detection limit 17.7 ng·mL-1 for BSA. This method was applied to the determination of the proteins in synthetic and human serum samples, and compared to the CBB method, with satisfactory results.
2005 Vol. 25 (06): 927-929 [Abstract] ( 1416 ) PDF (368 KB)  ( 364 )
930 Study on the Structure of Periodic and Chaotic Patterns of AMP-DC-Cu-Gel Systems
YIN Wen-xuan1, 2, LIU Yu-feng1, ZHAO Ying3, GAO Qing-yu2, WU Jin-guang1*
This is an in vitro model to mimic the conditions present during gallstone formation. Adenosine mono-phosphate (AMP), an important bio-molecule, was chosen. Its effect on the formation of periodic/chaotic patterns in the deoxycholate-CuCl2-gel and deoxycholate-CuCl2-glucose-gel systems were studied. FTIR spectroscopy was used to identify the structure of the precipitates. The results indicate that the patterns formed in the systems with AMP are different. And FTIR spectra show that AMP may also be involved in the coordination sphere of Cu2+ ion. The results are more complicated in the deoxycholate-CuCl2 system containing glucose, suggesting that the nonlinear scientific concept should be considered in understanding gallstone formation.
2005 Vol. 25 (06): 930-933 [Abstract] ( 1623 ) PDF (637 KB)  ( 342 )
934 A Study on Preparation and Characteristic of RuO2/TiO2 Coupled Photocatalyst
YAO Bing-hua1, WANG Li-ming1, YU Xiao-jiao1, YANG Guo-nong1, ZHAO Gao-yang1，ZHENG Huai-li2
RuO2/TiO2 coupled photocatalyst was prepared by sol-gel-dipping method. Being a model reaction, the photocatalytic degradation of direct fast black G was investigated in RuO2/TiO2 powder suspension irradiated by UV-lamp. The results showed that the addition of RuO2 to TiO2 greatly enhanced its photocatalytic activity, and the optimum dipped content of RuO2 was 0.16%, the optimum value of the calcinations temperature and the addition of RuO2/TiO2 powder were 500 ℃ and 5.00 g·L-1, respectively. The photocatalytic degradation of direct fast black G was experimentally demonstrated to follow the Langmuir-Hinshelwood kinetic model, and the adsorption constant (14.22 L·mmol-1) and the reaction rate constant [4.94×10-3 mmol(L·min)-1] were determined, respectively.
2005 Vol. 25 (06): 934-937 [Abstract] ( 480 ) PDF (466 KB)  ( 395 )
938 Development of High Speed UV-Vis Spectrophotometer
HUANG Mei-zhen1，NI Yi1，LIN Feng2，YUAN Bo1，DOU Xiao-ming1，ZHAO Hai-ying1，HUANG Wei-shi1
A high speed spectrophotometer based on a linear CCD was developed. The function and structure of the hardware and the software for the instrument were discussed. The elementary performance was tested as follows: wavelength range 200-820 nm, full spectrum scan time ＜0.1 s, spectral bandwidth 0.7 nm, wavelength accuracy ±1 nm, photometric accuracy ±0.005 AU, baseline flatness ＜0.001 AU(rms), and stray light ＜0.1％. Results showed that this instrument is easy to use, fast and with high analytical performance. In addition, it has internet function of remote control and remote access. With the powerful data processing and spectrum analyzing software, it will provide a strong tool for routine analysis and the research on dynamic reaction in chemistry and biology fields.
2005 Vol. 25 (06): 938-941 [Abstract] ( 1098 ) PDF (577 KB)  ( 325 )
942 Partial Least-Squares Regression Analysis for Simultaneous Spectrophotometric Determination of Fe3+ and Al3+
PENG Shu-chuan,HUANG Chuan-hui,CHEN Tian-hu,JIANG Shao-tong, FENG You-liang
Adding hexodecyltrimethylammonium bromide(CTMAB) to improve solubility and delicacy, and using chromazurol S as a chromogenic reagent, and acetone as a stabilizing reagent, partial least-squares regression(PLS) was used to determine simultaneously trace amounts of Fe(Ⅲ) and Al(Ⅲ) in sythetic samples. Considering the stability of the rays, and the absorption properties of the two ingredients, seven wavelengths between 610 and 670 nm were selected for data collection. As a comparison, the methods of CPA and PLS were used respectively for analysing the data obtained from the experiment, and the results suggested that the latter was much better.
2005 Vol. 25 (06): 942-944 [Abstract] ( 1524 ) PDF (334 KB)  ( 330 )
945 XPS Characterization of Auto-Reconditioning Layer on Worn Metal Surfaces
YANG He, ZHANG Zheng-ye, LI Sheng-hua, JIN Yuan-sheng
An auto-reconditioner package for in situ reconditioning of worn surfaces of machinery parts under normal running was applied to diesel engines of DF locomotives. A reconditioning layer was generated on the cylinder bore after running a mileage of 300 000 km, and no wear was measured for the piston rings and cylinder bores. Evaluations with SEM, nanohardness tester and XPS indicated that the protective layer assumed a thickness of 8-10 μm, a nano-hardness twice as high as that of the cast iron substrate, and a main elemental composition of Fe, O and C corresponding to the existence of Fe3O4 and Fe3C. A possible formation mechanism of the protective layer was suggested based on the mechanochemical activation of metal surfaces and the catalytic activation of the auto-reconditioner molecules.
2005 Vol. 25 (06): 945-948 [Abstract] ( 2149 ) PDF (616 KB)  ( 358 )
949 Microwave-Assisted Route to Fibre-Like Ternary NaFeS2 Nanoparticles and Its XPS
WU Hua-qiang,SHAO Ming-wang, GU Jia-shan, WEI Xian-wen
Ternary NaFeS2 nanoparticles were obtained in aqueous solution at room temperature via microwave-assisted route. The products were fibre-like with the diameter less than 10 nm, which were characterized with X-ray diffraction (XRD) pattern, transmission electron microscope (TEM) image, selected area electron diffraction (SAED) pattern and X-ray photoelectron spectroscope (XPS) pattern. The results indicated that the composition of fibre-like ternary nanoparticles are with atomic ratio of Na∶Fe∶S=1∶1.1∶1.9. The mechanism for the formation of fibre-like NaFeS2 nanoparticles is discussed.
2005 Vol. 25 (06): 949-951 [Abstract] ( 1491 ) PDF (432 KB)  ( 392 )
952 Determination of the Valence Change of Copper Concentrate Ore Sample during Depositing by Conventional X-Ray Fluorescence Spectrometer
YING Xiao-hu, CHEN Shao-hong
The peak position and line shape of S Kα, S Kβ satellite line, and the ratio of (S Kα/S Kβ), (Cu Lα/Cu Kα), and (Fe Lα/Fe Kα) of copper concentrate samples with different depositing methods were determined by a conventional X-ray fluorescence spectrometer. It is concluded that the valence of S, Cu and Fe changed during depositing in accordance with the changes of the lines. Copper concentrate sample(main mine phase is chalcopyrite, containing a little pyrite) was oxidized apparently after 2 years depositing. Part of S2-, Cu+ and Fe2+ in the sample were oxidized to high valence, and the sulphur atom combined with oxygen atom. The oxidation of the sample was influenced markedly by the storing method.
2005 Vol. 25 (06): 952-954 [Abstract] ( 1530 ) PDF (335 KB)  ( 359 )
955 Determination of As and Se in Animal and Plant Samples by the Normal ICP-MS with and without Octupole Reaction System and the ICP-MS with ORS
SHI Yan-zhi1, WANG Ying-feng1, HE Run-juan1,CHEN Deng-yun2
Some certified reference materials (CRMs) were digested and the elemental concentrations were determined by ICP-MS instrument, and the results include not only the trace key elements such as As, Pb, Hg and Cd but also the major components such as P, Ca, Fe, K, Na etc. The digestion method, the recoveries, and the detection limits are discussed to prove the reliability of ICP-MS and EPA200.8 method for the determination of the elements in food and plant samples. The ICP-MS instrument with ORS (octupole reaction system) was applied to the determination of As, Se etc, and the results are compared with those from the normal ICP-MS without ORS. The removal of ArCl and ArAr interference is discussed, and the advantage of ORS is proved by measuring the As and Se in some CRMs.
2005 Vol. 25 (06): 955-959 [Abstract] ( 1033 ) PDF (522 KB)  ( 349 )
960 Determination of Distribution and Effective Distribution Coefficient of Cr3+ in LiNbO3 Single Crystals Using UV/Visible Absorption Spectra and ICP
XIA Hai-ping, WANG Jin-hao, ZENG Xian-lin, ZHANG Jian-li, ZHANG Xin-min，NIE Qiu-hua
The LiNbO3 crystals doped with Cr3+ ion (Cr:LN) and co-doped with Cr3+ and Zn ions (Zn:Cr:LN) were grown by the Bridgman method. The absorption coefficient and concentration of Cr3+ in crystals were measured by UV/Visible spectra and inductively coupled plasma (ICP) spectrometry, respectively. The effective distribution coefficients (k) of Cr3+ in the crystals were calculated. The results indicated that the k for Cr: LN crystal decreased from 3.75 to 2.49 as the incorporating concentration of Cr3+ increased from 0.1 to 0.5 mol%; the introduction of ZnO in Cr:LN induced the reduction of k value effectively. However, the k value increased from 1.85 to 2.25 as the incorporating concentration of ZnO increased from 3 to 6 mol%. The variation of the k value was explained by the suppressing effect of ZnO on the incorporation of Cr3+ ions and the distribution of Cr3+ in LN.
2005 Vol. 25 (06): 960-963 [Abstract] ( 431 ) PDF (413 KB)  ( 351 )
964 Determination of Trace Arsenic and Selenium in Jellyfish by Microwave Digestion-Hydride Generation-Atomic Fluorescence Spectrometry
LIU Xi-guang1，2,YU Hua-hua1, ZHAO Zeng-qin1, LI Zhi-en1, XU Zu-hong1,LI Peng-cheng1*
A method of hydride generation-atomic fluorescence spectrometry was proposed in the present paper for the determination of trace arsenic and selenium in jellyfish. The samples were treated by the combination of microwave digestion and lyophilization. The optimal conditions for treating and analyzing samples were established. The problem of the effect of the superfluous acid in the digesting solution on the results was solved, and the influence of coexisting foreign ions on the determination of arsenic and selenium was investigated. The accuracy of the method was confirmed by the method of standard additions. This method proved to be simple, rapid and repeatable, and is suitable for the analysis of biologic samples containing water.
2005 Vol. 25 (06): 964-967 [Abstract] ( 1707 ) PDF (495 KB)  ( 364 )
968 Determination of Stability Constant of Glutamate Zinc by Indirect Determination of FAAS with ZnS
LIU Wen-han, ZHANG Dan, LI Zu-guang, WANG Li-li
Based on indirect determination of glutamic acid by flame atomic absorption spectrometry with ZnS and the complexing action mechanism, the determination of stability constant of glutamate zinc was studied. Under the selected condition of pH 9.0, the stability constant of glutamate zinc is between 3.3×1020 and 1.4×1021, the average value is βW＝1.03×1021, and log βW＝21.013.
2005 Vol. 25 (06): 968-970 [Abstract] ( 1065 ) PDF (319 KB)  ( 358 )
971 Preparation and Spectral Properties of PVP-Modified CdS Nanorods
YUAN Qiu-li1，NIE Qiu-lin1，2，CHEN Wei-xiang2，XU Zhu-de2
Polyvinylpyrrolidone(PVP)-modified CdS nanorods were prepared by a hydrothermal reaction of CdCl2·2.5H2O and (NH4)2S with 10 wt% ethylenediamine aqueous solution as solvent and 1.0 wt% PVP as additives. The obtained products were characterized by means of XRD，TEM，IR，DTA-TG，UV-Vis and PL spectroscopies. The surface-modified CdS nanorods showed narrow size distribution and enhanced luminescence property compared with that of the unmodified ones. The UV-Vis spectra exhibited a structure peak. These results were attributed to the surface passivation of the CdS nanorods by the PVP molecules.
2005 Vol. 25 (06): 971-974 [Abstract] ( 1454 ) PDF (515 KB)  ( 359 )
975 Synthesis and Spectral Analysis of Metal-N-Glycoside Complexes and Studies of Catalyzed Ester Hydrolytic Kinetics
ZHANG Wei, JIANG Tao*, REN Su-mei, ZHANG Zhong-wei, GUAN Hua-shi
Four new complexes of Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ) and Co(Ⅲ) with HL(HL=N,N′-di-β-D-glucosylethylenediamine) have been synthesized in methanol solutions. The compositions of the complexes determined by elementary analysis are [Ni(HL)(H2O)2]2+Cl2·CH3OH·2H2O，[Cu(HL)]2+Cl2·CH3CH2OH·3H2O，[Zn(HL)]2+Cl2·H2O and [Co(HL)(H2O)(OH)]2+Cl2·CH3OH·2H2O respectively. They were also characterized by IR, UV and NMR spectra which show that complexes of Ni(Ⅱ) and Co(Ⅲ) have octahedral configuration, while complexes of Cu(Ⅱ) and Zn(Ⅱ) have tetralhedral configuration. The hydrolytic kinetics of p-Nitrophenyl picolinate(PNPP) catalyzed by these complexes in buffer solution was also studied spectrophotometrically.
2005 Vol. 25 (06): 975-978 [Abstract] ( 1585 ) PDF (515 KB)  ( 314 )
979 Study on Intelligent System of Hyper-Spectral Data Gathering Based on GPS in Farm Machinery
LI Zhi-wei1,PAN Jian-jun1*,ZHANG Jia-bao2
In order to meet the precision agriculture needs that highly dense and overall farmland information is gathered, this system uses Visual Basic and Map-Objects to carry on integration of GPS, GIS and RS. On the one hand, the system can provide the space seat attribute of high precision for the spectral data gathered by way of integration GPS, and realizes integration in spectrum data gathering, orientation and storage. On the other hand, by way of integrated GIS, the system has realized the function of visualizing analysis and management of the spectrum data, displaying real-time trace of moving point, providing some related attribute of the moving point in map layers，and calculating crop derivative spectra and crop vegetation index NDVI etc. The sufficient information is put forward for expert system and decision support system of precision agriculture.
2005 Vol. 25 (06): 979-983 [Abstract] ( 1029 ) PDF (788 KB)  ( 396 )
984 Spectrum Analysis of Crop and Weeds at Seedling
MAO Wen-hua1，WANG Yue-qing1，WANG Yi-ming1*，ZHANG Xiao-chao2
The infestation information on field weeds is the basis of variable spraying herbicides. It was found that the method using the spectral characteristics of plant is superior in real-time respect. The Fourier transform infrared spectrum technique was applied to measure the reflectance of wheat and weeds in the range from 700 to 1 100 nm. The discrimination analysis was done using the SPSS software. Firstly, the source spectrum data were compressed and normalized. Secondly, the characteristic wavelengths were selected by using stepwise method. Thirdly, the discrimination model was set up to use the selected wavelengths as the variables for detecting wheat and weeds. It was shown by the result of discrimination analysis that the correct classification rate of wheat and weeds detection with the selected wavelength points achieved 97%. In addition, the selected wavelength points were marked in the “red edge” of reflectance within some range, and the rate of correct classification increased with the increase in the numbers of the selected wavelength points. According to the selected wavelength points, the proper filters were chosen to perform the multi-spectral images captured and processed with the machine vision system.
2005 Vol. 25 (06): 984-987 [Abstract] ( 1521 ) PDF (595 KB)  ( 332 )
988 Formation Mechanism of Sr2CeO4 and Its Effect on Spectral Properties
FU Shi-liu, DAI Jun, ZHAO Wei-ren
The phase composition of SrCO3 and CeO2 (2∶1) powder mixture calcined at different temperatures was identified by X-ray diffraction method. It was found that there were two types of formation mechanism of Sr2CeO4. When the starting powder mixture was fired above 1 000 ℃, the unstable intermediate phase SrCeO3 developed, which then reacted with SrCO3 to form the final product Sr2CeO4, however when the sintering temperature was lower, SrCO3 and CeO2 were converted directly to Sr2CeO4. The excitation spectra of Sr2CeO4 were quite different for different formation mechanism. The strong excitation band presented maxima at about 280 nm for the samples formed by the former mechanism, while the maxima were at about 254 nm for the samples formed by the latter mechanism. The formation mechanism had no effect on the emission spectra.
2005 Vol. 25 (06): 988-991 [Abstract] ( 1027 ) PDF (476 KB)  ( 328 )
992 Formation of Cu(Ⅱ) with Chitosan and the Study of GFC Spectra Study on the Molecular Weight Distribution of Oligosaccharides by Oxidizing Degradation
CHEN Yi-ping1, HAO Hong-yuan1, ZHANG Qi1, 2*, GE Qing-kai1, WANG Ping-hong1
Complexes of chitosan with Cu(Ⅱ) were prepared by adding Cu(OAc)2·H2O to chitosan solution. IR, UV, elemental analysis, and thermal weight analysis were used to characterize the complex. The results showed that there were coordinate bands formed. H2O2 was used to degrade chitosan-Cu(Ⅱ) complex, and the molecular distribution of degraded products was investigated. The result suggested that the chitosan could be degraded rapidly, the degradation started from higher molecular weight range, and the molecular weight distribution of oligosaccharides was much more narrow than that of degraded products with usual methods, such as hydrolysis acidic and oxidizing conditions. The index of molecular weight distribution changed with the average degradability. When exceeding 10 oligosaccharides, the smaller the DP, the smaller the index.
2005 Vol. 25 (06): 992-995 [Abstract] ( 1926 ) PDF (415 KB)  ( 353 )
996 Using Neural Networks Based Template Matching Method to Obtain Redshifts of Normal Galaxies
XU Xin1，2，LUO A-li2，WU Fu-chao1，ZHAO Yong-heng2
Galaxies can be divided into two classes: normal galaxy (NG) and active galaxy (AG). In order to determine NG redshifts, an automatic effective method is proposed in this paper, which consists of the following three main steps: (1) From the template of normal galaxy, the two sets of samples are simulated, one with the redshift of 0.0-0.3, the other of 0.3-0.5, then the PCA is used to extract the main components, and train samples are projected to the main component subspace to obtain characteristic spectra. (2) The characteristic spectra are used to train a Probabilistic Neural Network to obtain a Bayes classifier. (3) An unknown real NG spectrum is first inputted to this Bayes classifier to determine the possible range of redshift, then the template matching is invoked to locate the redshift value within the estimated range. Compared with the traditional template matching technique with an unconstrained range, our proposed method not only halves the computational load, but also increases the estimation accuracy. As a result, the proposed method is particularly useful for automatic spectrum processing produced from a large-scale sky survey project.
2005 Vol. 25 (06): 996-1001 [Abstract] ( 1139 ) PDF (669 KB)  ( 361 )
1002 An Automated Measurement of the Galaxies Spectra of LAMOST
ZHU Guang-hua, LUO A-li,ZHAO Yong-heng
To measure redshifts of the marge amount of galaxies’ spectra automatically is the main goal of the data processing for the LAMOST project (Large Sky Area Multi-Object Optical Fiber Spectroscopic Telescope). A method called PCAZ can be applied to measure the very small redshifts (generally z＜0.2) due to the restriction of the wavelength range of the templates that are composed to make orthogonal templates. In the present article, the authors break the restriction by improving PCAZ method according to the characteristic of LAMOST spectra. Applying this new method to the SDSS data, more than 90% of the results are correct. The maximum limitation for redshift measurement of this new method depends on the wavelength range of the templates and the S/N of the blue parts of the spectra. According to the spectral feature of LAMOST, the authors can measure the galaxies with z＜0.8 correctly. From the experiment the authors concluded：first, this method can be used to measure the redshift of LAMOST spectra; second, the authors need to compose self-contained templates of various galaxies (UV-IR) to measure the survey redshift; finally, the S/N of the blue end of the spectra influences the measurement of the large redshift.
2005 Vol. 25 (06): 1002-1005 [Abstract] ( 708 ) PDF (416 KB)  ( 381 )

　CopyRight © OFFICE OF SPECTROSCOPY AND SPECTRAL ANALYSIS
　Address: NO.76 Collage South Road of Beijing 　Postalcode:100081
　Tel. (010)62181070　E-mail:chngpxygpfx@vip.sina.com
　Support by Beijing Magtech Co.ltd　E-mail:support@magtech.com.cn