Journals >Spectroscopy and Spectral Analysis
Contents
2012
Volume: 32 Issue 2
62 Article(s)
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Research Article
A Primary Study of 8～14 μm Band Emittance
YU Kun, LIU Yu-fang, JIA Guang-rui, and SHI De-heng
According to the previous experimental results, the band emittance of two materials were computed for 8～14 mm bandwidth in infrared measuring. The band emittance of several materials was surveyed by a simple experiment. The experiment and reckoning show that there is some kind of functional relation between band emittaAccording to the previous experimental results, the band emittance of two materials were computed for 8～14 mm bandwidth in infrared measuring. The band emittance of several materials was surveyed by a simple experiment. The experiment and reckoning show that there is some kind of functional relation between band emittance and temperature. If the object measured is non-gray, and emissivity is regarded as a constant, acute measurement error will be generated for band pass radiation thermometer and thermal imaging system. The band emittance is nearly linear with the temperature for nonmetal and metal in vacuum by primary analysis. The fitted function equation can be used as the modification of band pass radiation thermometer and thermal imaging system, and the band emittance not only simplifies the calculation, but also improves the accuracy of measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 289 (2012)
Experimental Investigation on Plasma Assistant Combustion Actuator in Argon/Air
DU Hong-liang, HE Li-ming, DING Wei, ZHAO Bing-bing, and WANG Feng
In order to obtain the characteristics of argon/air plasma assistant combustion actuators, experiments of three different actuators with normal, paratactic and meshy electrode configurations were respectively performed in argon/air mixture firstly, the results showed that the shape of electrode has little influence on In order to obtain the characteristics of argon/air plasma assistant combustion actuators, experiments of three different actuators with normal, paratactic and meshy electrode configurations were respectively performed in argon/air mixture firstly, the results showed that the shape of electrode has little influence on the discharge characteristics. Then normal electrode was applied to study spectrum and discharge characteristics under the condition of 100% air and 10% argon/90% air. The comparison showed that, though in mixture the law of discharge characteristic was the same as that of pure air, discharge current and emission spectrum were strengthened, and initial discharge voltage reduced from 27 to 24 kV..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 293 (2012)
Photoemission Characteristic of Transmission-Mode Extended Blue GaAs Photocathodes
SHI Feng, ZHAO Jing, CHENG Hong-chang, ZHANG Yi-jun, XIONG Ya-juan, and CHANG Ben-kang
Based on the theoretical models of computing the photocathode optical performance, quantum yield and integral sensitivity, the photoemission characteristics of the domestic and ITT’s transmission-mode extended blue GaAs photocathodes, namely the cathode optical properties and performance parameters, were respectively iBased on the theoretical models of computing the photocathode optical performance, quantum yield and integral sensitivity, the photoemission characteristics of the domestic and ITT’s transmission-mode extended blue GaAs photocathodes, namely the cathode optical properties and performance parameters, were respectively investigated. The compared results show that the integral sensitivity of the domestic transmission-mode extended blue photocathode has achieved 2 100 μA·lm-1, still falling behind the ITT’s integral sensitivity of 2 750 μA·lm-1. The reasons for the difference in quantum yield curves are that, on one hand, the thickness of GaAlAs window-layer and the Al mole fraction play a critical role in the short-wavelength response, especially in the extended blue region. On the other hand, the cathode performance parameters such as electron diffusion length and back interface recombination velocity work on the long-wavelength and short-wavelength response. All these factors are subject to the backwardness of basic industrial manufacturing level..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 297 (2012)
Resonance Wavelength Effects on Sensitivity of Resonant Grating Waveguide Biosensor
JIA Ke-hui, and MA Jun-shan
Resonant grating waveguide (RGW) biosensor has been widely investigated in recent years. The system has several advantages such as minimizing, label-free, high throughput, real time monitoring and so on. The sensitivity of RGW biosensor was theoretically analyzed for different resonance wavelength. Sensitivity to the rResonant grating waveguide (RGW) biosensor has been widely investigated in recent years. The system has several advantages such as minimizing, label-free, high throughput, real time monitoring and so on. The sensitivity of RGW biosensor was theoretically analyzed for different resonance wavelength. Sensitivity to the refractive index and thickness of the sample was analyzed using rigorous coupled wave analysis method. Results indicate that the sensitivity to refractive index is constant for a certain resonance wavelength as the thickness of sample does not change. The sensitivity to refractive index is enhanced with the increase of resonance wavelength. RGW with 1 250 nm resonance wavelength is approximately 4 times as sensitive as RGW with 830 nm resonance wavelength. The sensitivity to thickness drastically decreased at first, and then achieved zero for a certain resonance wavelength as the refractive index of sample is invariable. It was showed that it is limited to test sample thickness for every RGW. RGW with 1 250 nm resonance wavelength is approximately 2 times the measure range as RGW with 830 nm resonance wavelength. The sensitivity to thickness is enhanced with the increase of resonance wavelength. RGW with 1 250 nm resonance wavelength is approximately 3 times as sensitive as RGW with 830 nm resonance wavelength. The above results reveal that the sensitivity to both sample refractive index and sample thickness is enhanced with the increase of resonance wavelength. And the capability of testing sample thickness improves with longer resonance wavelength. The results provided the theory basis for resonance wavelength choice of RGW biosensor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 302 (2012)
Study on Spectral Line Profile of Different Types of Filaments in Dielectric Barrier Discharge
DONG Li-fang, SHANG Jie, JI Ya-fei, LIU Liang, and LI Xin-chun
The variations of width and shifts of Ar Ⅰ(2P2→1S5) spectral line emitted from two types of filaments, whose diameters and states are different, in argon/air dielectric barrier discharge with the change in air content were researched for the first time. In order to measure the wavelength shift, Ar Ⅰ(2P2→1S5) spectral lThe variations of width and shifts of Ar Ⅰ(2P2→1S5) spectral line emitted from two types of filaments, whose diameters and states are different, in argon/air dielectric barrier discharge with the change in air content were researched for the first time. In order to measure the wavelength shift, Ar Ⅰ(2P2→1S5) spectral line emitted from argon discharge at pressure of 10 Pa was used as a reference line. Regular arrangements of static wide filaments (static big dots) and moving thin filaments (reciprocating moving small dots whose traces are lines) were obtained in discharge at atmospheric pressure when the air content was in the range of 0.4%～4%. The variations of width and shifts of Ar Ⅰ(2P2→1S5) spectral line emitted from the big and small dots with the change in air content were measured respectively. It was found that they all increase with the increasing in air content. The width and shift of small dot are bigger than those of the big dot at any air content. The difference between the former and the latter decreases with the increase in air content firstly and remains basically unchanged after the air content reaches up to 1%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 306 (2012)
White Light Upconversion Luminescence and Its Mechanism of Yb3+/Ho3+/Tm3+ Co-Doped Tellurite Glass
PAN Xin-xiang, ZHONG Hai-yang, XING Ming-ming, and WANG Yi-zhuo
Yb3+/Ho3+, Yb3+/Tm3+ and Yb3+/Ho3+/Tm3+ co-doped tellurite glasses were prepared by melt-quenching method. Under the excitation of 980 nm laser, Yb3+/Ho3+/Tm3+ co-doped glass sample shows strong blue, green and red emissions, corresponding to the transitions 1G4 →3H6 of Tm3+, 5F4(5S2)→5I8 of Ho3+, as well as 5F5→5I8 ofYb3+/Ho3+, Yb3+/Tm3+ and Yb3+/Ho3+/Tm3+ co-doped tellurite glasses were prepared by melt-quenching method. Under the excitation of 980 nm laser, Yb3+/Ho3+/Tm3+ co-doped glass sample shows strong blue, green and red emissions, corresponding to the transitions 1G4 →3H6 of Tm3+, 5F4(5S2)→5I8 of Ho3+, as well as 5F5→5I8 of Ho3+ and 1G4 →3F4 of Tm3+ ions, respectively. It was found that the integrated emission intensity ratio of the red to green in Yb3+/Ho3+/Tm3+ co-doped sample (3.95) is greater than that in Yb3+/Ho3+ co-doped sample (1.69) due to the cross-relaxation between Ho3+ and Tm3+ ions : 3H4(Tm3+)+5I6(Ho3+)→3F4(Tm3+)+5F5(Ho3+), and 3F4(Tm3+)+5I8(Ho3+)→3H6(Tm3+)+5I7(Ho3+). When the pump power density is 8.2 W·cm-2, the calculated color coordinates of Yb3+/Ho3+/Tm3+ co-doped sample are x=0.345, y=0.338, which is very close to the equal energy white light(x=0.333, y=0.333)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 309 (2012)
The Linearity Analysis of Ultrahigh Temperature FTIR Spectral Emissivity Measurement System
WANG Zong-wei, DAI Jing-min, HE Xiao-wa, and YANG Chun-ling
To study thermal radiation properties of special materials at high temperature in aerospace fields, the ultrahigh temperature spectral emissivity measurement system with Fourier spectrometer has been established. The linearity of system is the guarantee of emissivity measurement precision. Through measuring spectral raTo study thermal radiation properties of special materials at high temperature in aerospace fields, the ultrahigh temperature spectral emissivity measurement system with Fourier spectrometer has been established. The linearity of system is the guarantee of emissivity measurement precision. Through measuring spectral radiation signals of a blackbody source at different temperatures, the function relations between spectral signal values and blackbody spectral radiation luminance of every spectrum points were calculated with the method of multi-temperature and multi-spectrum linear fitting. The spectral radiation signals of blackbody were measured between 1 000 ℃ and 2 000 ℃ in the spectral region from 3 to 20 μm. The linear relations between spectral signal and theory line at wavelength of 4 μm were calculated and introduced. The spectral response is well good between 4 and 18 μm, the spectral linearity are less than 1% except CO2 strong absorption spectrum regions. The results show that when the errors of measured spectrum radiation and linear fitting theory lines are certain, the higher the temperature, the smaller the spectral errors on emissivity. The linearity analysis of spectrum response is good at eliminating errors caused by individual temperature’ disturbance to the spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 313 (2012)
Study on the Effect of High Hydrostatic Pressure Treatment on the Secondary Structure of Mushroom Polyphenoloxidase by SRCD and FTIR
YI Jian-yong, DONG Peng, WANG Yong-tao, JIANG Bin, LIAO Xiao-jun, HU Xiao-song, and ZHANG Yan
The secondary structure of the mushroom polyphenoloxidase treated by the high hydrostatic pressure (HHP) was analyzed by the synchrotron radiation circular dichroism (SRCD) and Fourier transform infrared spectroscopy (FTIR). The α-helix content of mushroom PPO was decreased after HHP treatment, which indicated that theThe secondary structure of the mushroom polyphenoloxidase treated by the high hydrostatic pressure (HHP) was analyzed by the synchrotron radiation circular dichroism (SRCD) and Fourier transform infrared spectroscopy (FTIR). The α-helix content of mushroom PPO was decreased after HHP treatment, which indicated that the secondary structure of PPO was changed. There was a discrepancy of the result of the secondary structure content between untreated or HHP-treated mushroom PPO analyzed by SRCD and FTIR spectra, and this discrepancy may be due to the different determination temperature, the concentration of the PPO solution and the spectra analysis method etc. The fluorescence spectra showed that the fluorescence intensity of the mushroom PPO was decreased after HHP treatment, and a red shift was observed after HHP treatment, which indicated that the tertiary structure of the enzyme molecule has been modified..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 317 (2012)
FTIR and XPS Analysis of Characteristics of Synthesized Zeolite and Removal Mechanisms for Cr(Ⅲ)
FAN Chun-hui, MA Hong-rui, HUA Li, WANG Jia-hong, and WANG Hai-jun
Zeolite products were synthesized from fly ash using one-stage method, and the characteristics of zeolite were analyzed with approaches of XRD, SEM and ζ potential, the removal mechanism for Cr(Ⅲ) was further investigated by FTIR and XPS. From the pH value of 8 to 12, the negative ζ potential of NaP1 zeolite products dZeolite products were synthesized from fly ash using one-stage method, and the characteristics of zeolite were analyzed with approaches of XRD, SEM and ζ potential, the removal mechanism for Cr(Ⅲ) was further investigated by FTIR and XPS. From the pH value of 8 to 12, the negative ζ potential of NaP1 zeolite products decreased from -8.72 to -24.46 mV. The pseudo-second-order kinetics equation and Langmuir isotherm fit better the reaction, the maximum adsorption capacity was 33.557 0 mg·g-1. Functional groups of —OH and Si—O were important for Cr(Ⅲ) removal shown from FTIR spectra. The Cr(2p3/2) peak was found at the binding energy of 576.45 eV, indicating the effectiveness of reaction. The binding energy of Si—Si and Si—O increased by 0.25 eV and 0.60 eV, respectively, coordination effect might work between functional groups and Cr(Ⅲ), and O(1s) binding energy decreased after the adsorption process. The removal for Cr(Ⅲ) on zeolite was the comprehensive results of physical and chemical adsorption effects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 324 (2012)
Evaluation of Nutrient Release Profiles from Polymer Coated Fertilizers Using Fourier Transform Mid-Infrared Photoacoustic Spectroscopy
SHEN Ya-zhen, DU Chang-wen, ZHOU Jian-min, WANG Huo-yan, and CHEN Xiao-qin
The acrylate-like materials were used to develop the polymer coated controlled release fertilizer, the nutrients release profiles were determined, meanwhile the Fourier transform mid-infrared photoacoustic spectra of the coatings were recorded and characterized; GRNN model was used to predict the nutrients release profThe acrylate-like materials were used to develop the polymer coated controlled release fertilizer, the nutrients release profiles were determined, meanwhile the Fourier transform mid-infrared photoacoustic spectra of the coatings were recorded and characterized; GRNN model was used to predict the nutrients release profiles using the principal components of the mid-infrared photoacoustic spectra as input. Results showed that the GRNN model could fast and effectively predict the nutrient release profiles, and the predicted calibration coefficients were more than 0.93; on the whole, the prediction errors (RMSE) were influenced by the profiling depth of the spectra, the average prediction error was 10.28%, and the spectra from the surface depth resulted in a lowest prediction error with 7.14%. Therefore, coupled with GRNN modeling, Fourier transform mid-infrared photoacoustic spectroscopy can be used as an alternative new technique in the fast and accurate prediction of nutrient release from polymer coated fertilizer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 330 (2012)
Determination of Cationic Degree in PDA with Near Infrared Reflectance Spectroscopy
ZHENG Huai-li, ZHANG Peng, CHEN Yu-zhe, TAN Ming-zhuo, JIANG Shao-jie, ZHU Chuan-jun, ZHU Guo-cheng, MA Jiang-ya, and ZHANG Zhao-qing
Cationic degree has been investigated as an important factor in polyacrylamide materials. Diallyl dimethyl ammonium chloride and acrylamide (PDA) was grafted by free radical polymerisation of acrylamide monomer (AM) onto the cationic monomer dimethyl diallyl ammonium chloride (DMDAAC). In the present study, near infrarCationic degree has been investigated as an important factor in polyacrylamide materials. Diallyl dimethyl ammonium chloride and acrylamide (PDA) was grafted by free radical polymerisation of acrylamide monomer (AM) onto the cationic monomer dimethyl diallyl ammonium chloride (DMDAAC). In the present study, near infrared reflectance spectroscopy(NIRS) was used as a rapid and accurate method to determine the cationic degree in the PDA. In this experiment, the near infrared spectra of 37 PDA samples that were self-prepared in the laboratory from 900.00 to 1 700.00 were collected. The characteristic peaks and the entire spectrum segment as the input layer neurons in radical basis function(RBF) were investigated for establishing the mathematical conversion NIRS calibration mode. For reduction of the NIR spectrum noise, the wavelet analysis was used as pretreatment process. The measured value was determined by using precipitation titration and a comparison between the simulated value and measured value was made. It was found that the external validation determination coefficient was more than 0.9, and the simulation value is in good agreement with the measured value. The statistics analysis showed that there was no significant difference between simulated value and measured value. Therefore, the calibration model (RBF neural network) established in this paper exhibited a remarkable feasibility for predicting the cationic degree of PDA based on the near infrared spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 334 (2012)
Anomalous Absorption and a Qualified Far Infrared Spectrum
HU Yan-qin, CHEN Yu-jing, LI Hui-hua, and WANG Hai-shui
The ideal 100% line could not be obtained when the content of water vapor in the spectrometer is constant but high during the whole procedure of a far-infrared spectrum collection. This result indicates that anomalous absorption phenomenon takes place in high relative humidity atmosphere. In the present paper, the inflThe ideal 100% line could not be obtained when the content of water vapor in the spectrometer is constant but high during the whole procedure of a far-infrared spectrum collection. This result indicates that anomalous absorption phenomenon takes place in high relative humidity atmosphere. In the present paper, the influences of the relative humidity of ambient air and spectral resolution on anomalous absorption were studied. It was found that both decreasing the water vapor content in the spectrometer and adopting low spectral resolution are effective methods to avoid anomalous absorption. Furthermore, the water vapor bands can be eliminated by “dry air and wet air titration” in the fluctuant humidity. This provides us a quick and economic method to obtain a qualified far infrared spectrum conveniently. It should be noticed that the working condition for “dry air and wet air titration” is low relative humidity to prevent water vapor abnormal absorption..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 339 (2012)
Research on Calibration Methods of Ground-Based Thermal-Infrared Radiometer CE312
LIU Li, GU Xing-fa, YU Tao, LI Xiao-ying, CHEN Xing-feng, GAO Hai-liang, and LI Jia-guo
The accuracy of the calibration coefficients of the ground-based thermal-infrared radiometer CE312 is one of the most important factors affecting the calibration of the thermal-infrared remote sensors. The theory of two calibration methods which calculate the bandpass radiance and spectral radiance respectively is intrThe accuracy of the calibration coefficients of the ground-based thermal-infrared radiometer CE312 is one of the most important factors affecting the calibration of the thermal-infrared remote sensors. The theory of two calibration methods which calculate the bandpass radiance and spectral radiance respectively is introduced. The calibration of the CE312-1b is conducted with the blackbody in the laboratory, the accuracy and influence factors of the results are conducted by the MODIS data combined with in situ measurements data at Qinghai Lake in Aug 2010. The results show that calibration coefficients of thermal-infrared field radiometer CE312 calculated by the bandpass radiance method has better performance in the accuracy and applicability than the spectral radiance method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 343 (2012)
Prediction of Soil Organic Carbon in Different Soil Fractions of Black Soils in Northeast China Using Near-Infrared Reflectance Spectroscopy
FAN Ru-qin, YANG Xue-ming, ZHANG Xiao-ping, SHEN Yan, LIANG Ai-zhen, SHI Xiu-huan, WEI Shou-cai, and CHEN Xue-wen
The soil organic carbon (SOC) associated with different soil fractions varies in the composition and dynamics. The present work is aimed to evaluate the potential of near infrared spectroscopy (NIRS) to predict SOC content in different soil fractions of black soils. SOC contents of 136 black soil samples in China were The soil organic carbon (SOC) associated with different soil fractions varies in the composition and dynamics. The present work is aimed to evaluate the potential of near infrared spectroscopy (NIRS) to predict SOC content in different soil fractions of black soils. SOC contents of 136 black soil samples in China were analyzed and the NIR spectra were collected using a VECTOR/22 (Fourier transform infrared spectroscopy). Partial least squares (PLS) regression with cross validation was used to develop calibrations between reference data and NIRS spectra (n=100) which were validated using an independent set of samples (n=36). Predictions for water-sieved aggregate associated organic carbon were generally good with R2 (coefficient of determination) ranging from 0.69 to 0.82 and the RPD (residual prediction deviation) from 1.2 to 1.8. NIRS well predicted the SOC in <53 μm mineral fraction (R2=0.97, RPD=5.4), but the prediction for SOC in 250～2 000 μm or in 53～250 μm particulate matter fractions was poor. However, the prediction for the SOC in 53～2 000 μm fraction was good (R2=0.79, RPD=2.2). In addition, NIRS very well predicted the SOC in fine particle fraction (<20 μm) (R2=0.93, RPD=3.8). Accordingly, NIRS showed a good potential to predict SOC in some soil fractions and could reduce tedious laboratory analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 349 (2012)
Qualitative and Quantitative Detection of Minced Pork Quality by Near Infrared Reflectance Spectroscopy
CHENG Fang, FAN Yu-xia, and LIAO Yi-tao
The present study is concerning qualitative and quantitative detection of minced pork quality based on FT-near infrared (FT-NIR) spectroscopy and achieving the rapid approach to detecting the minced pork quality. Firstly, FT-NIR spectroscopy combined with partial least squares (PLS) and least squares-support vector macThe present study is concerning qualitative and quantitative detection of minced pork quality based on FT-near infrared (FT-NIR) spectroscopy and achieving the rapid approach to detecting the minced pork quality. Firstly, FT-NIR spectroscopy combined with partial least squares (PLS) and least squares-support vector machine (LS-SVM) was used for minced pork quality prediction including discrimination of the different muscle type of pig and quantitative detection of the fat, protein and moisture content of pork. The result indicated that 100% recognition ratio for calibration and 96% recognition ratio for validation were achieved by PLSDA for 4 different muscle types of pig. These two methods for chemical composition detection both have good performances in predicting fat and moisture content, the correlation coefficient for calibration and validation was all more than 0.9, but the models for protein content prediction were of less well performances, the correlation coefficients for calibration and validation, RMSEC, RMSEP and RMSECV respectively were 0.722, 0.593, 1.595, 1.550 and 1.888, respectively. The LS-SVM method is more accurate in predicting each quality index than the PLSR method. The result shows that the prediction models for fat and moisture content based on LS-SVM have a better performance with high precision, good stability and adaptability and can be used to predict the fat and moisture content of minced pork rapidly, and provide a fast approach to discrimination of the different muscle type of pig..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 354 (2012)
FTIR Detection of Unregulated Emissions from a Diesel Engine with Biodiesel Fuel
TAN Pi-qiang, HU Zhi-yuan, and LOU Di-ming
Biodiesel, as one of the most promising alternative fuels, has received more attention because of limited fossil fuels. A comparison of biodiesel and petroleum diesel fuel is discussed as regards engine unregulated exhaust emissions. A diesel fuel, a pure biodiesel fuel, and fuel with 20% V/V biodiesel blend ratio wereBiodiesel, as one of the most promising alternative fuels, has received more attention because of limited fossil fuels. A comparison of biodiesel and petroleum diesel fuel is discussed as regards engine unregulated exhaust emissions. A diesel fuel, a pure biodiesel fuel, and fuel with 20% V/V biodiesel blend ratio were tested without engine modification. The present study examines six typical unregulated emissions by Fourier transform infrared spectroscopy (FTIR) method: formaldehyde (HCHO), acetaldehyde (C2H4O), acetone (C3H6O), toluene (C7H8), sulfur dioxide (SO2), and carbon dioxide (CO2). The results show addition of biodiesel fuel increases the formaldehyde emission, and B20 fuel has little change, but the formaldehyde emission of pure biodiesel shows a clear trend of addition. Compared with the pure diesel fuel, the acetaldehyde of B20 fuel has a distinct decrease, and the acetaldehyde emission of pure biodiesel is lower than that of the pure diesel fuel at low and middle engine loads, but higher at high engine load. The acetone emission is very low, and increases for B20 and pure biodiesel fuels as compared to diesel fuel. Compared with the diesel fuel, the toluene and sulfur dioxide values of the engine show a distinct decrease with biodiesel blend ratio increasing. It is clear that the biodiesel could reduce aromatic compounds and emissions of diesel engines. The carbon dioxide emission of pure biodiesel has a little lower value than diesel, showing that the biodiesel benefits control of greenhouse gas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 360 (2012)
Calibration Methods of Infrared Spectra for Geographical Origins Determination of Radix Zanthoxyli
HUANG Shu-shi, LI Zi-da, MAO Xiao-li, ZHENG Juan-mei, LIU Jun-xian, and HUANG Rong-shao
The instrument and the experimental environment influence the infrared spectra, which may limited the identification of the samples by a prediction model. Based on the Fourier transform infrared spectroscopy (FTIR) technology, the authors performed different infrared spectral calibration methods for Radix Zanthoxyli geThe instrument and the experimental environment influence the infrared spectra, which may limited the identification of the samples by a prediction model. Based on the Fourier transform infrared spectroscopy (FTIR) technology, the authors performed different infrared spectral calibration methods for Radix Zanthoxyli geographical origins determination, the SIMCA was used to establish an identification models, and the model was used to distinguish samples from four different regions of Guangxi. According to the result of prediction, the authors could obtain the most suitable calibration method for the identification model. The results showed that, respectively, by the multiple scattering correction and standard normal variation, their PCA data distribution and the distance between models is ideal, suggesting that we can eliminate the interference from the environmental and human factors by these two correction methods, and also separate each samples of different habitats. The test using the method to measure the geographical origins of Radix Zanthoxyli proved that the recognition rate and rejection rate are both at or near 100%. Visible, and both the multiplicative scatter correction and the standard normal variation are all the ideal calibration methods for Radix Zanthoxyli infrared spectral geographical origins determination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 364 (2012)
Analysis of Transgenic and Non-Transgenic Rice Leaves Using Visible/Near-Infrared Spectroscopy
ZHU Wen-chao, and CHENG Fang
Visible/near-infrared (Vis/NIR) spectroscopy was investigated for the fast discrimination of rice leaves with different genes and the determination of chlorophyll content. Least squares-support vector machines (LS-SVM) was employed to discriminate transgenic rice leaves from non-transgenic ones. The classification accuVisible/near-infrared (Vis/NIR) spectroscopy was investigated for the fast discrimination of rice leaves with different genes and the determination of chlorophyll content. Least squares-support vector machines (LS-SVM) was employed to discriminate transgenic rice leaves from non-transgenic ones. The classification accuracy of calibration samples reached to 100%. Successive projections algorithm (SPA) was proposed to select effective wavelengths. SPA-LS-SVM discrimination model was performed, and the result indicated that an 87.27% recognition ratio was achieved using only 0.3% of total variables. The optimal performance of each quantification model was achieved after orthogonal signal correction (OSA). Performances treated by SPA were better than that of full-spectrum PLS, which indicated that SPA is a powerful way for effective wavelength selection. The best performance of quantification was obtained by SPA-LS-SVM model; with correlation coefficient (R) and root mean square error of prediction (RMSEP) being 0.902 2 and 1.312 1, respectively. Excellent classification and prediction precision were achieved. The overall results indicated that the new proposed SPA-LS-SVM is a powerful method for varieties recognition and SPAD prediction. This study supplied a new and alternative approach to the further application of Vis/NIR spectroscopy in on-field classification and monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 370 (2012)
Study of Density Functional Theory for Surface-Enhanced Raman Spectra of Furfural
CHEN Yan, CHEN Shan-jun, YI Zao, LUO Jiang-shan, YI You-gen, and TANG Yong-jian
In the present paper, DFT method at the B3LYP/6-31+G**(C, H, O)/LANL2DZ(Ag) level was used to optimize molecular configurations of furfural. Based on the optimized structure, the normal Raman spectrum (NRS) of FUR and the surface-enhanced Raman spectrum (SERS) of FUR adsorbed on Ag, Ag2 and Ag4 were all calculated, whiIn the present paper, DFT method at the B3LYP/6-31+G**(C, H, O)/LANL2DZ(Ag) level was used to optimize molecular configurations of furfural. Based on the optimized structure, the normal Raman spectrum (NRS) of FUR and the surface-enhanced Raman spectrum (SERS) of FUR adsorbed on Ag, Ag2 and Ag4 were all calculated, which were compared with the experimental values. The calculation results indicated that a good conformity was found between the computed and the experimental results. The results of furfural adsorbed on Ag4 were more approximate to the ever reported experimental date than those of furfural adsorbed on Ag and Ag2. At the end, detailed analysis of the Raman spectrum and more comprehensive assignments of the vibration mode for furfural were studied by the software of GaussView. The data of the SERS by comparing with the one of NRS show that furfural molecule and Ag atoms interact with each other. And we suppose that the molecular plane with the ring of adsorbed furfural molecule is vertically orientated to the silver surface. The work in this paper offers a theory evidence for detection and trace analysis of drinks containing furfural..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 374 (2012)
In Situ Experimental Study of Phase Transition of Calcite by Raman Spectroscopy at High Temperature and High Pressure
LIU Chuan-jiang, and ZHENG Hai-fei
The phase transitions of calcite at high temperature and high pressure were investigated by using hydrothermal diamond anvil cell combined with Raman spectroscopy. The result showed that the Raman peak of 155 cm-1 disappeared, the peak of 1 087 cm-1 splited into 1083 and 1 090 cm-1 peaks and the peak of 282 cm-1 abruptThe phase transitions of calcite at high temperature and high pressure were investigated by using hydrothermal diamond anvil cell combined with Raman spectroscopy. The result showed that the Raman peak of 155 cm-1 disappeared, the peak of 1 087 cm-1 splited into 1083 and 1 090 cm-1 peaks and the peak of 282 cm-1 abruptly reduced to 231 cm-1 at ambient temperature when the system pressure increased to 1 666 and 2 127 MPa respectively, which proved that calcite transformed to calcite-Ⅱ and calcite-Ⅲ. In the heating process at the initial pressure of 2 761 MPa and below 171 ℃, there was no change in Raman characteristic peaks of calcite-Ⅲ. As the temperature increased to 171 ℃, the color of calcite crystal became opaque completely and the symmetric stretching vibration peak of 1 087 cm-1, in-plane bending vibration peak of 713 cm-1 and lattice vibration peaks of 155 and 282 cm-1 began to mutate, showing that the calcite-Ⅲ transformed to a new phase of calcium carbonate at the moment. When the temperature dropped to room temperature, this new phase remained stable all along. It also indicated that the process of phase transformation from calcite to the new phase of calcium carbonate was irreversible. The equation of phase transition between calcite-Ⅲ and new phase of calcium carbonate can be determined by P(MPa)=9.09T·(℃)+1 880. The slopes of the Raman peak (ν1 087) of symmetrical stretching vibration depending on pressure and temperature are dν/dP=5.1(cm-1·GPa-1) and dν/dT=-0.055 3(cm-1·℃-1), respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 378 (2012)
Raman Spectroscopic Study on the Influence of Ultraviolet-A Radiation on Collagen Ⅰ
MA Rong-tian, GUO Zhou-yi, LIU Zhi-ming, ZHONG Hui-qing, ZHUANG Zheng-fei, and ZHAI Juan
Raman spectroscopy was used to study the influence of ultraviolet-A(UV-A) radiation on collagenⅠ. The Raman spectra of collagenⅠ and that after 90 min UV-A radiation were reported. The results proved that irradiation with 90 min UV-A caused the change in the structures of collagenⅠ. Intramolecular hydrogen bonds were bRaman spectroscopy was used to study the influence of ultraviolet-A(UV-A) radiation on collagenⅠ. The Raman spectra of collagenⅠ and that after 90 min UV-A radiation were reported. The results proved that irradiation with 90 min UV-A caused the change in the structures of collagenⅠ. Intramolecular hydrogen bonds were broken, and the hydrogen bonding system was changed. The intensity of helix was decreased, while the intensity of the disordered conformation in proteins such as random coil was increased. Otherwise, the UV-A radiation influenced the hydroxylation of proline and the content of hydroxyproline was reduced. The changes caused by UV-A radiation could damage the triple helical structure of collagenⅠ. It would lead to a series of changes, such as the destruction of collagen fibers during the photoaging of skin..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 383 (2012)
Fabrication of Silver Ordered Nanoarrays SERS-Active Substrates and Their Applications in Bladder Cancer Cells Detection
LIU You, HUANG Li-qing, WANG Jun, TONG Hui-min, YUAN Lin, ZHAO Li-hua, ZHANG Wei-wei, WANG Lei, and ZHU Jian
Highly ordered silver nanopore and nanocap arrays, which were used as surface-enhanced Raman scattering active (SERS-active) substrates, were fabricated by electron-beam evaporating silver on the surface of porous layer and barrier layer of porous anodic alumina (PAA) membranes, respectively. The SERS characteristics oHighly ordered silver nanopore and nanocap arrays, which were used as surface-enhanced Raman scattering active (SERS-active) substrates, were fabricated by electron-beam evaporating silver on the surface of porous layer and barrier layer of porous anodic alumina (PAA) membranes, respectively. The SERS characteristics of the SERS-active substrates were tested with bladder cancer cells as molecular probe. The results indicated that both the SERS-active substrates displayed a strong SERS enhancement effect. The silver nanocap ordered arrays SERS-active substrate displayed not only higher SERS and fluorescence quenching effect, but also no interferential spectrum related with oxalate impurity remaining in PAA membranes, and therefore can result in the high quality Raman spectroscopy of bladder cancer cells..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 386 (2012)
Surface Enhanced Raman Spectroscopy (SERS) of Saliva for the Diagnosis of Lung Cancer
LI Xiao-zhou, YANG Tian-yue, and DING Jian-hua
Surface enhanced Raman spectroscopy (SERS) has shown the advantage of detecting low concentration biofluids presently. Saliva SERS of 21 lung cancer patients and 22 normal people were measured and differentiated in the present paper. Intensities of most peaks of lung cancer patients are weaker than that of normal peoplSurface enhanced Raman spectroscopy (SERS) has shown the advantage of detecting low concentration biofluids presently. Saliva SERS of 21 lung cancer patients and 22 normal people were measured and differentiated in the present paper. Intensities of most peaks of lung cancer patients are weaker than that of normal people, while some stronger but with a small change rate. Those peaks were assigned to proteins and nucleic acids which indicate a corresponding decrease of those substances in saliva. Principal component analysis (PCA) and linear discriminant analysis (LDA) were used to deduce and discriminate the two groups of data, resulting in accuracy, sensitivity, and specificity being 84%, 94%, and 81%, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 391 (2012)
Detection and Analysis of Several Kinds of Oils with Raman Spectrum
BAO Li-li, QI Xiao-hua, ZHANG Xiao-fang, TENG Wen-feng, ZOU Ming-qiang, LIU Feng, and ZHANG Cheng
Applying Raman spectrometry to detect several kinds of oils such as petrol, diesel oil, naphtha and KHF (aviation fuel hydro treating), the authors can explore the regular laws existing among these oils. The authors detected 150 cases of oils using Raman spectrometer developed by ourselves with 785 nm excitation waveleApplying Raman spectrometry to detect several kinds of oils such as petrol, diesel oil, naphtha and KHF (aviation fuel hydro treating), the authors can explore the regular laws existing among these oils. The authors detected 150 cases of oils using Raman spectrometer developed by ourselves with 785 nm excitation wavelength miniature portable, and dealed with these spectra-paragraphs of the oils on level and SNV (normalization method) methods. The spectrograms of four categories of oils including petrol, diesel oil, naphtha and KHF and also the additives of them have different characteristics and rules. According to the alkenes peak’s location and intensity we can distinguish petrol and naphtha, and then screen out some unqualified petrol. Raman spectrometry is very simple and has advantages that it needs a small amount of oil samples, at the same time, it also has no damage to test samples. The spectra-paragraphs show that different kinds of samples have different character on location and intensity of Raman peak. The Raman spectrometry method has great potential on establishing a rapid oil screening detection and identification method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 394 (2012)
Vibrational Spectra of Hetian Nephrite from Xinjiang
ZHANG Yong-wang, LIU Yan, LIU Tao-tao, Muhetaer Zari, and LIU Yuan-qing
In previous studies, EMPA, PIXE and others were employed to study the chemical compositions of nephrite separately without a systematical measurement. In the present study, XRF, XRD, IR and LR were used together to examine chemical and spectra characteristics of white, green and black nephrite from Hetian, Xinjiang. XRIn previous studies, EMPA, PIXE and others were employed to study the chemical compositions of nephrite separately without a systematical measurement. In the present study, XRF, XRD, IR and LR were used together to examine chemical and spectra characteristics of white, green and black nephrite from Hetian, Xinjiang. XRD results indicate that all nephrite samples consist of tremolite. Then IR spectra of nephrite samples suggest that the M—OH stretching vibration bands show that the M1 and M3 sites are not only occupied by Mg2+ and Fe2+, but also by Fe3+, which is consistent with the chemical compositions of these samples. This information might be useful to understanding the variety of nephrite. Their Raman spectra are almost the same, while some differences exist because of different content of FeO/Fe2O3..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 398 (2012)
Research on Optical Fiber SPR Humidity Sensor and Resonance Spectrum Characteristic
ZHANG Shao-hua, ZENG Jie, SUN Xiao-ming, MU Hao, and LIANG Da-kai
A new type of humidity sensor based on optical fiber SPR sensor probe was introduced and manufactured. Firstly the sensitivity of optical fiber SPR sensor probe to environment humidity was studied. On this basis, coating with thin PVA film of different thickness and with capacity of adsorbing water molecule on the surfA new type of humidity sensor based on optical fiber SPR sensor probe was introduced and manufactured. Firstly the sensitivity of optical fiber SPR sensor probe to environment humidity was studied. On this basis, coating with thin PVA film of different thickness and with capacity of adsorbing water molecule on the surface of optical fiber SPR sensor probe, for the purpose of monitoring relative humidity was proposed. The research shows that the SPR sensor probe coated with double layers of thin PVA film gets better detection result, and humidity measurement sensitivity is 1.59%/%RH, being improved notably compared with SPR optical fiber probe. The SPR sensor coated with single layer of thin PVA film has relative humidity measuring sensitivity of 2.411 nm/%RH related to resonance wavelength in high humidity area. In addition, the new type of optical fiber humidity-sensitive probe with PVA film losing efficiency can be reusable after special treatment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 402 (2012)
Study on Ca2+ Transmembrane Behaviors of Magnetic-Treated S.aureus with Fura-2/AM Fluorescence Probe and LCSM
MA Hai-le, XU Shen-shi, HE Rong-hai, and DUAN Yu-qing
The purpose of the present paper is to study Ca2+ transmembrane behaviors of the S.aureus treated with high intensity pulsed magnetic field. For this purpose, the method of Fura-2/AM fluorescence probe was investigated to determine the change in intracellular Ca2+ concentration in S.aureus, fluorescence intensities of The purpose of the present paper is to study Ca2+ transmembrane behaviors of the S.aureus treated with high intensity pulsed magnetic field. For this purpose, the method of Fura-2/AM fluorescence probe was investigated to determine the change in intracellular Ca2+ concentration in S.aureus, fluorescence intensities of S.aureus cells treated by pulsed magnetic field under different pulse number were determined, and the change in intracellular Ca2+ concentration was observed by laser confocal scanning microscope (LCSM). Research results showed that Fura-2/AM can load in S.aureus successfuuly, and can be used to determine the change in intracellular free Ca2+ concentration. After being treated with high intensity pulsed magnetic field, intracellular free Ca2+ concentration of S.aureus went up significantly, and the regulation of Ca2+ increase was close consistent with the decrease in living bacterium number, and relatedness reached to -0.989 15; the number and fluorescence intensity of intracellular lightspot increased significantly, meaning that large amount of exocellular calcium ions across cell membrane enter into inside of cells. So, it was judged that the change in microbial membrane permeability and increase in intracellular free Ca2+ concentration are important reasones why high intensity pulsed magnetic field has sterilization effect..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 407 (2012)
Thermoluminescence Characteristics of Lu2SiO5∶Ce Phosphors
WU Fei, LIU Xiao-lin, GU Mu, NI Chen, HUANG Shi-ming, and LIU Bo
To investigate the origin of the thermoluminescence at high temperature, Lu2SiO5∶Ce0.006(LSO∶Ce)phosphors were prepared by sol-gel chemistry in air and graphite respectively. The patterns of X-ray diffraction, excitation and emission spectra and thermoluminescence curves of these samples were analyzed. In comparison wiTo investigate the origin of the thermoluminescence at high temperature, Lu2SiO5∶Ce0.006(LSO∶Ce)phosphors were prepared by sol-gel chemistry in air and graphite respectively. The patterns of X-ray diffraction, excitation and emission spectra and thermoluminescence curves of these samples were analyzed. In comparison with the phosphors prepared in the air, the luminescence intensity was improved and the thermoluminescence peak at 598 K was restrained for the sample prepared in graphite. It was found that the thermoluminescence peak at 598 K was relevant to Ce4+. In order to achieve more evidences, LSO∶Ce0.006,Kx(x=0.01～0.08) phosphors were prepared. The structures and spectra of K+-codoped samples were also studied. By codoping with K+ ions, the luminescence intensity of LSO∶Ce phosphor could be enhanced distinctly, but the crystallinity was not improved. The results of the K+-codoped LSO∶Ce exhibited that K+-codoping could improve the concentration of oxygen vacancy and restrain the peak at 598 K. When K+ ion occupied the position of Lu3+, more oxygen vacancies could be created and Ce4+ turned into Ce3+ simultaneously due to the balance of electric charge, which was consistent with the result of the thermoluminescence. So it can also come to the conclusion that the thermoluminescence peak at 598 K was relevant to Ce4+. The reason for K+ ions enhancing the intensity of LSO∶Ce can be attributed to the improvement of concentration ratio for Ce3+/Ce4+..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 411 (2012)
Fluorescence Fingerprint Properties of Refinery Wastewater
WU Jing, XIE Chao-bo, CAO Zhi-ping, SUN Ya-nan, XIANG Xi, and DAI Chun-yan
Fluorescence organic matters contain the information about total amount and components of organic substances and could be treated as a novel water quality parameter to make up the ambiguity of COD and BOD about the pollutant composition. Refinery wastewater is a type of nonbiodegradable industrial wastewater containingFluorescence organic matters contain the information about total amount and components of organic substances and could be treated as a novel water quality parameter to make up the ambiguity of COD and BOD about the pollutant composition. Refinery wastewater is a type of nonbiodegradable industrial wastewater containing a large number of toxic pollutants. The investigation on the excitation-emission matrixes of the wastewater from a large-scale refinery plant indicated that the matrix was unique for each sample; the fluorescence was intensive and was derived from the overlaps of fluorescence related to peaks at around λex/λem=270/300 nm, 220/300 nm and 230/350 nm. The intensity of 270/300 nm was the highest and that of 220/300 nm was the secondly highest. The location and intensities of peaks varied within small ranges. The fluorescence of the refinery wastewater contains information about products and raw materials. Phenol significantly contributed to the fluorescence intensity of 270/300 nm and 220/300 nm, and other compounds with one benzene ring such as dichlorobenzene and benzene contributed to the two peaks too. The fluorescence of 230/350 nm would be closely related to alkane and benzene. The location and intensity of peaks would be used to diagnose if the performance of the manufacturing processes and influent of treatment plant is proper..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 415 (2012)
Study on the Characteristics of Three-Dimensional Fluorescence Excitation-Emission Spectra of Methanol and Ethanol
BU Gui-jun, HE Xiao-song, ZHENG Xiao-jiang, AI Xun-ru, and SHI You-xiang
For the purpose of revealing the spectra characteristics of methyl and ethanol, and establishing a method for distinguishing each other, the fluorescence features of methyl and ethanol were studied by three-dimensional fluorescence excitation-emission matrix spectra. The results obtained showed that there were two peakFor the purpose of revealing the spectra characteristics of methyl and ethanol, and establishing a method for distinguishing each other, the fluorescence features of methyl and ethanol were studied by three-dimensional fluorescence excitation-emission matrix spectra. The results obtained showed that there were two peaks in the three-dimensional fluorescence excitation-emission matrix spectra of methyl, and the intensities of the two peaks were positively related to the concentration of methyl when it was less than 15%. On the other hand, a whole fluorescence peak was only observed in the three-dimensional fluorescence excitation-emission matrix spectra of ethanol, and the intensity of the peak was positively correlated to the content of ethanol when it was less than 50%. There was a higher fluorescence efficiency for the methanol as compared to the ethanol. When the methyl was used for organic solvents to study the fluorescent nature of the organic matter, the fluorescence emitted by the methyl should be deduced. The locations of the fluorescence peaks of the methyl and ethanol were different. The peaks of the methyl were located at 225/350 nm and 250/375 nm, while the peak of the ethanol was characterized by 240/310 nm. Therefore, the fluorescence peak locations of the two alcohols could be applied to discriminate each other..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 420 (2012)
Application of Polarization Fluorescence to the Study on the Effects of Oxidative Stress on Wheat Chloroplast
FENG Juan, FENG Dan-dan, BAI Ying-nan, LIN Jun-yue, LI Jia-wei, and REN Zheng-long
In the present paper wheat flag leaves were collected during the tasseling period, and then 1 mmol·L-1 hydrogen peroxide was added to induce oxidative stress on leaves. In comparison, the detached leaves were also kept under drought or darkness condition for 24 h for the same purpose. Following the preparation of In the present paper wheat flag leaves were collected during the tasseling period, and then 1 mmol·L-1 hydrogen peroxide was added to induce oxidative stress on leaves. In comparison, the detached leaves were also kept under drought or darkness condition for 24 h for the same purpose. Following the preparation of chloroplasts, polarization fluorescence spectroscopic method was utilized to measure fluorescence emission spectra and fluorescence excitation spectra of chloroplasts in the case of VV, VH, HV and HH, where V and H is representative of vertical polarization and horizontal polarization, respectively. Gaussian deconvolution was done on emission spectra, and the fitting data revealed that no matter whether Chla or Chlb molecules were excited upon excitation at 436 nm or 475 nm, the ratio of fluorescence peak area at 684 nm and 720 nm, i.e. A684/A720, tends to increase slightly after oxidative stress. In addition, some useful information was available from polarization excitation spectra, where it was observed that the treatment of oxidative stress gave rise to higher ratio of excitation peak intensity between 436 nm and 475 nm (E436/E475), indicating that Chla made more contribution to PSII fluorescence emission than Chlb did. Simultaneously, the ratio of 475 nm and 600 nm (E475/E600), representing the energy transfer efficiency from Car to Chlb, was also found to be higher after the detached leaves were treated. In addition, both fluorescence polarization and viscosity were calculated in this paper, and the data showed that oxidative stress should be responsible for higher fluorescence polarization at 680 nm and higher viscosity in microenviroment. The above-mentioned phenomenon is consistent with the lipid peroxidation of unsaturated fatty acids. It also provides a simple and feasible method to study oxidative stress..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 425 (2012)
In-Flight Absolute Radiometric Calibration of UAV Hyperspectral Camera and Its Validation Analysis
GOU Zhi-yang, YAN Lei, CHEN Wei, JING Xin, YIN Zhong-yi, and DUAN Yi-ni
With the data in Urad Front Banner, Inner Mongolia on November 14th, 2010, hyper-spectral camera on UAV was calibrated adopting reflectance-based method. During the in-flight absolute radiometric calibration, 6 hyper-spectral radiometric gray-scale targets were arranged in the validation field. These targets' refleWith the data in Urad Front Banner, Inner Mongolia on November 14th, 2010, hyper-spectral camera on UAV was calibrated adopting reflectance-based method. During the in-flight absolute radiometric calibration, 6 hyper-spectral radiometric gray-scale targets were arranged in the validation field. These targets' reflectances are 4.5%, 20%, 30%, 40%, 50% and 60% separately. To validate the calibration result, four extra hyper-spectral targets with sharp-edge spectrum were arranged to simulate the reflection and absorption peaks in natural objectives. With these peaks, the apparent radiance calculated by radiation transfer model and that calculated through calibration coefficients are much different. The result shows that in the first 15 bands (blue bands), errors are somewhat huge due to the noises of equipment. In the rest bands with quite even spectrum, the errors are small, most of which are less than 10%. For those bands with sharp changes in spectral curves, the errors are quite considerable, varying from 10% to 25%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 430 (2012)
The Prediction of Barley Grain Protein Content Based on Hyperspectral Data
GU Zhi-hong
The prediction of crop grain protein by hyperspectral data has the nondestructive and quick advantages. At present, there are only a few reports about the prediction of barley grain protein by remote sensing. The present research focuses on the malt barley of Northeast China. Firstly, we analyzed the sensitive band areThe prediction of crop grain protein by hyperspectral data has the nondestructive and quick advantages. At present, there are only a few reports about the prediction of barley grain protein by remote sensing. The present research focuses on the malt barley of Northeast China. Firstly, we analyzed the sensitive band area, compared many vegetation indexes related with the plant nitrogen. According to the mechanism of nitrogen transfer, the authors built the prediction model based on the hyperspectral vegetation indexes. Finally, we validated the results. It can meet the standard. The outcome shows that (1) the sensitive band region of barley plant nitrogen is 550～590 nm and 670～710 nm. (2) GRVI was significantly correlated with plant nitrogen. The relationship between GRVI and barley plant nitrogen had a coefficient of determination of R2=0.665 1. The results indicated that the prediction of barley grain protein by hyperspectral data is feasible. This research will be a strong scientific support for barley purchase..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 435 (2012)
Effects of Leaf Hair on Leaf Reflectance and Hyperspectral Vegetation Indices
GE Hao, LU Shan, and ZHAO Yun-sheng
Many hyperspectral vegetation indices have been used to estimate the biochemical contents such as pigment content, nondestructively. These reflectance indices are influenced by leaf hair, and the existence of the leaf hair affects the performance of the indices on the estimation of the biochemical contents. The presentMany hyperspectral vegetation indices have been used to estimate the biochemical contents such as pigment content, nondestructively. These reflectance indices are influenced by leaf hair, and the existence of the leaf hair affects the performance of the indices on the estimation of the biochemical contents. The present research studied the possible effects of the leaf hair on the reflectance of the same leaf before and after removal of leaf hair. The authors found that dehairing had decreased the reflectance between wavelength 400 and 1 000 nm, and the decrease depends on the wavelength. The changes of 39 hyperspectral indices before and after the hair removal were compared. The results revealed that some indices that only use visible wavebands or the near infrared wavebands such as CTR1: R695/R420, D740/D720, WBI: R900/R970, R860/(R550×R708) and REP (Red-edge position) were not affected much by the dehairing process and are thought relatively robust to estimate the biochemical contents..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 439 (2012)
Research on the Spectral Characteristics of Grassland in Arid Regions Based on Hyperspectral Image
ZHANG Chun-mei, and ZHANG Jian-ming
The grassland spectrum was got from Hyperion images of Shiyang River Basin using PPI, after FLAASH atmosphere correction, to understand the spectral characteristics quantitatively. The results show that red edge moves left, slope reduced, blue and yellow edge feature is abated, reflectance is higher in visible bands, aThe grassland spectrum was got from Hyperion images of Shiyang River Basin using PPI, after FLAASH atmosphere correction, to understand the spectral characteristics quantitatively. The results show that red edge moves left, slope reduced, blue and yellow edge feature is abated, reflectance is higher in visible bands, and lower near-infrared bands when grassland is at decline stage relative to the spectrum characteristics of grassland at well growthl. The red edge, green peaks, absorption valley location of blue and red light keep consistent for different coverage grassland, and spectrum absorption characteristics (band depth, width, area, symmetry) in visual bands change regularly as coverage increases, so it can be a basis for extraction or judgment of vegetation coverage..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 445 (2012)
Study on the Reflected and Hyperspectral Mixed-Pixel Character of Aquatic Plants and Water
SUN Tian-lin, ZHAO Yun-sheng, LIANG Ren-feng, and ZHANG Xia
A study on the reflected and hyperspectral mixed-pixel of aquatic plants and water was given by using a orthogonal experimental design with three factors and two levels. The results of F test suggest that for the single factors, the band and the area ratio of mixed-pixel on the reflected and hyperspectral mixed-pixel oA study on the reflected and hyperspectral mixed-pixel of aquatic plants and water was given by using a orthogonal experimental design with three factors and two levels. The results of F test suggest that for the single factors, the band and the area ratio of mixed-pixel on the reflected and hyperspectral mixed-pixel of the reflection effects are particularly significant, however, the detector angle had no significant effect under these experimental conditions; For the interaction, the band and the area ratio of mixed-pixel, the detector and the area ratio of mixed-pixel, the effects of these two interactions on the reflected and hyperspectral mixed-pixel are also particularly significant, This study did quantitative analysis of the factors affecting the reflected and hyperspectral mixed-pixel character and their interaction, and provided a new method for the indepth study of mixed-pixel..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 449 (2012)
Spectral Reflectance Response of Plant Leaf to Simulated UVB Stress
JIANG He-ming, JIANG Hong, ZHOU Guo-mo, HONG Xia, XIE Xiao-zan, and HUANG Mei-ling
In the present study, we evaluate the relative content of chlorophyll and spectral reflectance variations in the visible light under different intensity of UVB (L-UVB, CK and UVB) of three typical evergreen broadleaf plants in China subtropical area. In different simulated UVB condition, the experiment shows that diffeIn the present study, we evaluate the relative content of chlorophyll and spectral reflectance variations in the visible light under different intensity of UVB (L-UVB, CK and UVB) of three typical evergreen broadleaf plants in China subtropical area. In different simulated UVB condition, the experiment shows that different tree species have different UVB sensitivity, and chlorophyll content varies greatly with species, and the chlorophyll relative content with the filter UVB was significantly higher than with enhanced UVB. In the spectral reflectance of the visible part, it is generally higher with enhanced UVB’s treatment than with L-UVB treatment; and any treatments present adaptation, species under different stress. After roles of the different UVB intensity, for each tree species the visible part of the spectral reflectance shows difference between green and red mainly. The study results show that the subtropical evergreen broad-leaved species has a strong sensitivity to the UVB, and UVB response of different tree species varies greatly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 453 (2012)
Reduction of Hyperspectral Dimensions and Construction of Discriminating Models for Identifying Wetland Plant Species
LIU Xue-hua, SUN Yan, and WU Yan
The present paper researched and analyzed the hyperspectral data of wetland plant species often occurred in Beijing. The methods of Mahalanobis Distance (MD) and principal component analysis (PCA) were mainly applied to reduce the dimensions of hyperspectral data and to analyze and extract the features of spectra. The The present paper researched and analyzed the hyperspectral data of wetland plant species often occurred in Beijing. The methods of Mahalanobis Distance (MD) and principal component analysis (PCA) were mainly applied to reduce the dimensions of hyperspectral data and to analyze and extract the features of spectra. The authors use the extracted spectra to build identification models for identifying the wetland species. The authors then compared and evaluated the precisions of models and finally obtained the best discriminating model. The results showed that (1) the dimensions of hyperspectral data can be efficiently reduced by both MD and PCA methods. (2) The discriminating models established using the parameters extracted from the resulting spectra of MD and PCA could identify the wetland plants with high precisions of more than 90%. As a result, the conversion and usage of the hyperspectral data can help better understand and well extract the spectra of different wetland plants. Furthermore, the constructed discriminating models for wetland species could also be used in the future to guide us in mapping and monitoring of wetland ecosystem by applying the remote sensing data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 459 (2012)
Estimating Total Nitrogen Content in Wetland Vegetation Based on Measured Reflectance Spectra
LIU Ke, ZHAO Wen-ji, GUO Xiao-yu, WANG Yi-hong, SUN Yong-hua, and MIAO Qian
More and more urban wetlands have been supplied with reclaimed water. And monitoring the growth condition of large-area wetland vegetation is playing a very important role in wetland restoration and reconstruction. Recently, remote sensing technology has become an important tool for vegetation growth monitoring. The SoMore and more urban wetlands have been supplied with reclaimed water. And monitoring the growth condition of large-area wetland vegetation is playing a very important role in wetland restoration and reconstruction. Recently, remote sensing technology has become an important tool for vegetation growth monitoring. The South Wetland in the Olympic Park, a typical wetland using reused water, was selected as the research area. The leaf reflectance spectra and were acquired for the main wetland plants reed (Phragmites australis) and cattail (Typha angustifolia) with an ASD FieldSpec 3 spectrometer (350～2 500 nm). The total nitrogen (TN) content of leaf samples was determined by Kjeldahl method subsequently. The research established univariate models involving simple ratio spectral index (SR) model and normalized difference spectral index (ND) model, as well as multivariate models including stepwise multiple linear regression (SMLR) model and partial least squares regression (PLSR) model. Moreover, the accuracy of all the models was tested through cross-validated coefficient of determination (R2CV) and cross-validated root mean square error (RMSECV). The results showed that (1) comparing different types of wetland plants, the accuracy of all established prediction models using Phragmites australis reflectance spectra was higher than that using Typha angustifolia reflectance spectra. (2) compared with univariate techniques, multivariate regressions improved the estimation of TN concentration in leaves. (3) among the various investigated models, the accuracy of PLSR model was the highest (R2CV=0.80, RMSECV=0.24). PLSR provided the most useful explorative tool for unraveling the relationship between spectral reflectance and TN consistence of leaves. The result would not only provide a scientific basis for remote sensing retrieval of biochemical variables of wetland vegetation, but also provide a strong scientific basis for the monitoring and management of urban wetlands using recycled water..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 465 (2012)
Decomposition and Analysis of the Natural Source SLF Spectrum Using Curvelet Transform Method
JIANG Hong-bo, CHEN Chao, and QIN Qi-ming
Because natural source super low frequency (SLF) electromagnetic detection equipment receives wideband multi-source signal, how to decompose the signal to filter out the interference signal was a key factor for the application of natural source SLF electromagnetic detection technology. In the present article, the detecBecause natural source super low frequency (SLF) electromagnetic detection equipment receives wideband multi-source signal, how to decompose the signal to filter out the interference signal was a key factor for the application of natural source SLF electromagnetic detection technology. In the present article, the detection equipment developed by Peking University was used to survey the coal bed methane data in the Qinshui basin, Shanxi province, and the curvelet transform method was employed to decompose those data. The analysis results indicated that the high-frequency information coming from the decomposition is the interference signals mainly generated by lightning in the atmospheric and directly received by the detection equipment, while the low frequency signal mainly contains the target information. So the reconstructed curve based on the low-frequency information was more favorable for the interpretation of the target, compared with the original spectrum curve. But the curvelet transform method could not remove the artificial frequency signal..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 472 (2012)
Study on the Measurement of Ambient Ammonia in Urban Area Based on Open-Path DOAS Technique
WANG Jie, XIE Pin-hua, QIN Min, LING Liu-yi, YE Cong-lei, LIU Jian-guo, and LIU Wen-qing
As a key role in the acid-deposition and the generation of secondary particle matter (PM), measurement of the concentration of atmospheric ammonia in urban area has been attracting the scientists’ interests nowadays. After studying the special absorption features of ammonia in short UV wavelength range, detailed concerAs a key role in the acid-deposition and the generation of secondary particle matter (PM), measurement of the concentration of atmospheric ammonia in urban area has been attracting the scientists’ interests nowadays. After studying the special absorption features of ammonia in short UV wavelength range, detailed concernful issues were put forward in the present paper. The decision of using xenon lamp as the light source was made after the evaluation of measurement of light spectroscopy. Retrieval wavelength band for NH3 was fixed from 204 to 214 nm and optimal method of deducting other interferential gases was also shown. A home-made open-path DOAS (OP-DOAS) system was set up for the measurement of the concentration of atmospheric NH3. The detection limit of such system was calculated with the typical noise level as low as 0.33 μg·m-3 with the optical path 228 m. Through field experiment in Guangzhou city, such a system can be competent for the online and high time-resolution monitoring of the concentration of atmospheric ammonia. With a significant diurnal variation, the atmospheric ammonia changed from 0.83 to 3.11 μg·m-3 with the mean value 1.59 μg·m-3. The representative character of the diurnal variation is that the concentration of NH3 peaks during night while drops to bottom in the daytime. After the error analysis procedure, typical measurement accuracy of such OP-DOAS system was within 10%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 476 (2012)
Application and Progress of the Nondestructive Spectral Technology Used in Polychrome Ceramic Relics Analysis
WEI Lu, WANG Li-qin, ZHOU Tie, RONG Bo, and XIA Yin
The polychrome ceramic relics own abundant information which play an important role in studying ancient Chinese history, culture, economy, science and technology. Because the polychrome ceramic relics analysis couldn't be satisfied by common analytical methods, various kinds of nondestructive spectral technology haThe polychrome ceramic relics own abundant information which play an important role in studying ancient Chinese history, culture, economy, science and technology. Because the polychrome ceramic relics analysis couldn't be satisfied by common analytical methods, various kinds of nondestructive spectral technology have been introduced in this area gradually. This paper presented the theory, feature and limitation of the nondestructive spectral technology such as Laser Raman microscopic spectrum, laser induced breakdown spectra, and EDXRF from three parts: pigment analysis, ceramic analysis and relic information identification. Finally, the future development trends were discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 481 (2012)
Equalization of Whole-Band Signal’s SNR in the Blood Components Noninvasive Measurement
LI Gang, WANG Hui-quan, ZHANG Hao, LIN Ling, WU Xiao-rong, and ZHANG Bao-ju
To fully extend the category of blood components that can be noninvasively measured by dynamic spectrum (DS) method and to increase its measuring precision, an overall consideration of light source, tissue absorption and sensor’s sensitivity was made. Compensating the light source and adding the telecentric lens not onTo fully extend the category of blood components that can be noninvasively measured by dynamic spectrum (DS) method and to increase its measuring precision, an overall consideration of light source, tissue absorption and sensor’s sensitivity was made. Compensating the light source and adding the telecentric lens not only expand the spectral effective detecting range, but also balance the signal-to-noise ratio (SNR) of the photoelectric pulse in the whole band equalization. The integral SNR of DS signal was increased and the measurement bandwidth was expanded. The effectiveness of this method was validated by the quality evaluation criterion of DS data: the effective detecting range of visible DS was widened from 600~1 000 nm to 500~1 135 nm; the effective detecting range of near-infrared DS was widened from 900~1 100 nm to 900~1 700 nm. The results show that the design can create the condition for detection of new blood components noninvasively, and enhance the prediction accuracy of the blood components, for which noninvasive measuring using DS method has been achieved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 486 (2012)
Component Analysis of Complex Mixed Solution Based on Multidimensional Diffuse Reflectance Spectroscopy
LI Gang, XIONG Chan, ZHAO Li-ying, LIN Ling, TONG Ying, and ZHANG Bao-ju
In the present paper, the authors proposed a method for component analysis of complex mixed solutions based on multidimensional diffuse reflectance spectroscopy by analyzing the information carried by spectrum signals from various optical properties of various components of the analyte. The experiment instrument was deIn the present paper, the authors proposed a method for component analysis of complex mixed solutions based on multidimensional diffuse reflectance spectroscopy by analyzing the information carried by spectrum signals from various optical properties of various components of the analyte. The experiment instrument was designed with supercontinuum laser source, the motorized precision translation stage and the spectrometer. The Intralipid-20% was taken as an analyte, and was diluted over a range of 1%～20% in distilled water. The diffuse reflectance spectrum signal was measured at 24 points within the distance of 1.5～13 mm (at an interval of 0.5 mm) above the incidence point. The partial least squares algorithm model was used to perform a modeling and forecasting analysis for the spectral analysis data collected from single-point and multi-point. The results showed that the most accurate calibration model was created by the spectral data acquired from the nearest 1～13 points above the incident point; the most accurate prediction model was created by the spectral signal acquired from the nearest 1～7 points above the incident point. It was proved that multidimensional diffuse reflectance spectroscopy can improve the spectral signal to noise ratio. Compared with the traditional spectrum technology using a single optical property such as absorbance or reflectance, this method increased the impact of scattering characteristics of the analyte. So the use of a variety of optical properties of the analytes can make an improvement of the accuracy of the modeling and forecasting, and also provide a basis for component analysis of the complex mixed solution based on multidimensional diffuse reflectance spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 491 (2012)
Preparation by Template Method and Spectral Characterization of α-MoO3 Nanorods and Nanometer Rectangular Pieces
LIU Ying, FENG Jin-chao, and LI Jing
α-MoO3 was paid special attention to nano scale with its layered crystal structure and potential applications in material chemistry fields. In the present paper, (NH4)6Mo7O24·4H2O and hexadecyl trimethyl ammonium bromide (CTAB) were proposed as molybdenum precursor and template agent, respectively, and the precursα-MoO3 was paid special attention to nano scale with its layered crystal structure and potential applications in material chemistry fields. In the present paper, (NH4)6Mo7O24·4H2O and hexadecyl trimethyl ammonium bromide (CTAB) were proposed as molybdenum precursor and template agent, respectively, and the precursor was prepared by statistic ion exchange with strong acidic ion exchange resin (R-H). The precursor can be transformed into α-MoO3 nanorods and nanometer rectangular small pieces via calcining precursor at 600 ℃ for different times. The phasestate, structure and morphology of samples were identified by FTIR, XRD, TEM and SEM. The α-MoO3 nanorods with the length of about 1~1.6 μm, the diameter of about 0.10~0.20 μm and the ratio of length to diameter of 8, and the nanometer rectangular small pieces with the length of about 0.14~0.18 μm, the width of about 60~80 nm and the thickness of 28~32 nm, were obtained after 600 ℃ sintering for 4 and 8 h. This preparation procedure is simple, without the need for artificially adjusting the pH, redundantly washing can be avoided, the resin can be regenerated and NH4Cl was recycled without environmental pollution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 496 (2012)
UV Spectroscopy Coupled with Partial Least Squares to Determine the Enantiomeric Composition in Chiral Drugs
LI Qian-qian, WU Li-jun, LIU Wei, CAO Jin-li, DUAN Jia, HUANG Yue, and MIN Shun-geng
In the present study, sucrose was used as a chiral selector to detect the molar fraction of R-metalaxyl and S-ibuprofen due to the UV spectral difference caused by the interaction of the R- and S-isomer with sucrose. The quantitative model of the molar fraction of R-metalaxyl was established by partial least squares (PIn the present study, sucrose was used as a chiral selector to detect the molar fraction of R-metalaxyl and S-ibuprofen due to the UV spectral difference caused by the interaction of the R- and S-isomer with sucrose. The quantitative model of the molar fraction of R-metalaxyl was established by partial least squares (PLS) regression and the robustness of the models was evaluated by 6 independent validation samples. The determination coefficient R2 and the standard error of calibration set (SEC) was 99.98% and 0.003 respectively. The correlation coefficient of estimated value and specified value, the standard error and the relative standard deviation (RSD) of the independent validation samples was 0.999 8, 0.000 4 and 0.054% respectively. The quantitative models of the molar fraction of S-ibuprofen were established by PLS and the robustness of models was evaluated. The determination coefficient R2 and the standard error of calibration set (SEC) was 99.82% and 0.007 respectively. The correlation coefficient of estimated value and specified value of the independent validation samples was 0.998 1. The standard error of prediction (SEP) was 0.002 and the relative standard deviation (RSD) was 0.2%. The result demonstrates that sucrose is an ideal chiral selector for building a stable regression model to determine the enantiomeric composition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 500 (2012)
Column Chromatography Purification and Analysis of Biodiesel by Transesterification
LIU Yang, YI Huai-feng, CHEN Yu, WU Yu-long, YANG Ming-de, CHEN Zeng, and TONG Jun-mao
In the present paper, crude biodiesel prepared with sorbifolia oil as raw material by transesterification was purified by column chromatography, then the composition of biodiesel was analyzed by gas chromatography, FTIR, GC-MS and 1H NMR. Column chromatography can separate the crude biodiesel into two fractions: petrolIn the present paper, crude biodiesel prepared with sorbifolia oil as raw material by transesterification was purified by column chromatography, then the composition of biodiesel was analyzed by gas chromatography, FTIR, GC-MS and 1H NMR. Column chromatography can separate the crude biodiesel into two fractions: petroleum ether eluted fraction (A1) and methanol eluted fraction (A2). Petroleum ether eluted fraction was mainly biodiesel fraction, which was produced from sorbifolia oil by transesterification, including methyl linoleate, methyl cis-9-octadecenoate and so on; methanol eluted fraction was mainly glycerol fraction, which came from the side reaction of transesterification. The results show that the purity of refined biodiesel increased from 77.51% to 93.87%, and the product recovery rate reached up to 91.04% after the purification by column chromatography. The results obtained by FTIR and 1H NMR further showed that the column chromatography can effectively improve the purity of biodiesel. This paper provides a basis for industrialization of purification of biodiesel..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 505 (2012)
Data Mining Approach to Cataclysmic Variables Candidates Based on Random Forest Algorithm
JIANG Bin, LUO A-li, and ZHAO Yong-heng
An automatic and efficient method for cataclysmic variables candidates is presented in the present paper. The identified CVs were selected as templates. A model was constructed by random forest algorithm with templates and random selected spectra. Wavelength ranking was described by the model and the classifier was conAn automatic and efficient method for cataclysmic variables candidates is presented in the present paper. The identified CVs were selected as templates. A model was constructed by random forest algorithm with templates and random selected spectra. Wavelength ranking was described by the model and the classifier was constructed afterwards. Most of the non-candidates were excluded by the method. Template matching strategy was used to identify the final candidates which were analyzed to complement the templates as feedback. 16 new CVs candidates were found in the experiment that shows that our approach to finding special celestial bodies can be feasible in LAMOST..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 510 (2012)
Enrichment of Trace Iron with Activated Carbon in Bi-Based Superconductor Powder and Determination by Inductively Coupled Plasma Atomic Emission Spectroscopy
HUANG Wen-jie, LI Jian-qiang, FAN Hui-li, FAN Li-xin, BAO Rui, ZHANG Xia, WANG Jie, and LU Qing
A new method for determination of trace iron in superconductor powder by ICP-AES was proposed. The instrument parameters were optimized, and the matrix effects as well as the method of eliminating interferences were also studied systemically. The results showed that matrix interference was serious when the amount of maA new method for determination of trace iron in superconductor powder by ICP-AES was proposed. The instrument parameters were optimized, and the matrix effects as well as the method of eliminating interferences were also studied systemically. The results showed that matrix interference was serious when the amount of matrix increased, and the repeatability was poor, so it was necessary that separation and preconcentration were used to improve the accuracy and precision. In the experiment, complex was formed with Fe and phenanthroline after the matrix elements Bi and Cu were masked by triethanolamine in an appropriate acidity condition. Then the complex was quantitatively adsorbed by activated carbon, and desorbed by 1∶1 HNO3. The enrichment conditions were investigated in detail. Under the optimal condition, an artificial sample was analysed, and the result was identical with reference values, with the RSD and detection limit being 2.42% and 0.033 μg·g-1, respectively. The method was applied for the determination of trace iron in Bi-based superconductor powder samples with satisfactory results, in which the recoveries experiment was performed with the recovery coefficient falling in the range of 95.6% to 98.0%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 514 (2012)
Spectroscopic Characterization of Dissolubility and Surface Properties of Chalcopyrite in Aqueous Solution
DENG Jiu-shuai, WEN Shu-ming, XIAN Yong-jun, LIU Jian, and LIU Dan
The dissolubility and surface properties of chalcopyrite were studied in different mechanical stirring time and different pH value solution under argon and oxygen atmosphere by ICP-MS, AFM and XPS analysis. Besides, the XRD diffraction pattern and crystal structure of chalcopyrite and its dissolution model in aqueous sThe dissolubility and surface properties of chalcopyrite were studied in different mechanical stirring time and different pH value solution under argon and oxygen atmosphere by ICP-MS, AFM and XPS analysis. Besides, the XRD diffraction pattern and crystal structure of chalcopyrite and its dissolution model in aqueous solution were established. The laboratory results indicate that the relationship between copper and iron concentrations in solution and time in pure water can be derived as the equation c=ksat+b. The lower pH value makes it easier for chalcopyrite to dissolve, and that the surface oxidation is slow has minor effect on the dissolubility. In pure water, the dissolution of chalcopyrite has little influence on the effective specific surface area, and the dissolution is controlled by surface chemical reaction under acidic conditions. After long time dissolution, the surface of the chalcopyrite assumes copper-rich state relative to iron and the surface roughness and lattice imperfections increase..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 519 (2012)
Determination and Analysis of Trace Elements in Lycium Barbarum L. from Different Regions of Qinghai Province
YANG Ren-ming, SUO You-rui, and WANG Hong-lun
For comparison of the quality of Lycium barbarum L., the authors determined 11 trace elements in the fruits of Lycium barbarum L. from 12 different regions of Qinghai province by ICP-MS and ICP-AES. Meanwhile, 7 trace elements essential for human body were selected to the object of principal component analysis by SPSS For comparison of the quality of Lycium barbarum L., the authors determined 11 trace elements in the fruits of Lycium barbarum L. from 12 different regions of Qinghai province by ICP-MS and ICP-AES. Meanwhile, 7 trace elements essential for human body were selected to the object of principal component analysis by SPSS statistic software. Three principal component equations were obtained, and the regression equation related to principal component was also set up. The research is very important to quality analysis and to obtaining high quality Lycium barbarum L., and provided science basis for the development and utilization of Lycium barbarum L. in Qinghai province..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 525 (2012)
Determination of Mineral Elements in Bupleurum Based on ICP-AES
CUI Xu-sheng, DONG Xue-hui, and GUO Yu-hai
ICP-AES technique was used to determine the mineral elements in Bupleurum at different habitat. The results show that: (1) In Bupleurum, the content and accumulation of K was the highest among 5 macroelements, the content and accumulation of Fe was the highest among 5 microelements. (2) In Bupleurum, the content of Ca,ICP-AES technique was used to determine the mineral elements in Bupleurum at different habitat. The results show that: (1) In Bupleurum, the content and accumulation of K was the highest among 5 macroelements, the content and accumulation of Fe was the highest among 5 microelements. (2) In Bupleurum, the content of Ca, Mg, P, Na and Cu was high in habitat of Beijing, the content can respectively reach to 6.40, 3.84, 3.45, 4.97 mg·g-1, and 25.20 μg·g-1; while the content of K, Ca, Mg, P, Zn, Mn and Cu was low in habitat of Wanrong, and the content was only 12.43, 4.57, 1.92, 1.79 mg·g-1 and 50.04, 32.21, 15.43 μg·g-1 respectively. (3) In Bupleurum, the content of P∶K, Zn∶Fe, Cu and Mn was significantly different at different habitat, while Mg and Ca showed little difference. Conclusion: In Bupleurum, the content, accumulation and proportion of mineral elements were differenct at different habitat..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 529 (2012)
Determination of Total Selenium in Water by Hydride Generation Atomic Fluorescence Spectrometry
XU Yong-xin, and LUO Kun-li
In order to establish a rapid and accurate hydride generation-atomic fluorescence spectrometry method for the determination of selenium content in water samples, the influence factors on Se nitrolysis in the water such as nitrolysis temperature and the amount of hydrochloric acid were studied. The authors determined a In order to establish a rapid and accurate hydride generation-atomic fluorescence spectrometry method for the determination of selenium content in water samples, the influence factors on Se nitrolysis in the water such as nitrolysis temperature and the amount of hydrochloric acid were studied. The authors determined a simple and practical test method that is to add 3 mL hydrochloric acid at 3 ℃. We measured the precision and accuracy of the method by the standard liquid of 3, 6 and 10 μg·L-1, and the test results were 2.96, 5.43 and 9.66 mg·L-1.The recovery varied from 90.50% to 98.67%. Meanwhile we tested 29 water samples by different methods. The error of standard sample was 8.95％～25.46％by hydride generation-atomic fluoresence spectrometry in the GB/T 5750.6—2006, and the error of standard sample was 1.33％～3.40％ by new method. Compared with the national standards of GB/T 5750.6—2006, the method has the advantages of operating simplicity and and easy control, and it is also reliable and economical..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 532 (2012)
Analysis of Cd Pollution & Spatial Variability Characteristics of Typical Agricultural Soils in Suburbs of Urumqi City, Xinjiang
ZHENG Chun-xia, WU Hong-qi, ZHU Xin-ping, and JIA Hong-tao
Cd content in agricultural soils from 4 townships in north suburb and 2 townships in south suburb of Urumqi City was determined with graphite furnace (GF-990) atomic absorption spectrometry, and the spatial variability of Cd content there was analyzed with geo-statistics method. The result indicates that Cd content froCd content in agricultural soils from 4 townships in north suburb and 2 townships in south suburb of Urumqi City was determined with graphite furnace (GF-990) atomic absorption spectrometry, and the spatial variability of Cd content there was analyzed with geo-statistics method. The result indicates that Cd content from the sampling points in north suburb exceeds the stipulated standard and falls into medium or strong spatial variability with nugget value >75%, which explains a weak self-correlation among those variable spaces under mainly the impact of random factors of external pollution such as local fertilization level, irrigation and cultivation etc. Cd content from the sampling points in north suburb does not exceed the stipulated standard but approaches to the critical warning value with nugget value at 50.2%, which falls into medium self-correlation among those variable spaces. Spatial variability characteristics of Cd distribution in suburban agricultural soils of Urumqi City, Xinjiang were studied in this paper for providing scientific basic data to source analysis and control of Cd pollution in the far mLands there..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 537 (2012)
Determination of Trace Lead and Cadmium in Transgenic Rice by Crosslinked Carboxymethyl Konjac Glucomannan Microcolumn Preconcentration Combined with Graphite Furnace Atomic Absorption Spectrometry
LIU Hua-qing, LI Sheng-qing, QU Yang, and CHEN Hao
A novel method was developed for the determination of trace lead and cadmium in transgenic brown rice based on separation and preconcentration with a micro column packed with crosslinked carboxymethyl konjac glucomannan (CCMKGM) prior to its determination by graphite furnace atomic absorption spectrometry. Variables afA novel method was developed for the determination of trace lead and cadmium in transgenic brown rice based on separation and preconcentration with a micro column packed with crosslinked carboxymethyl konjac glucomannan (CCMKGM) prior to its determination by graphite furnace atomic absorption spectrometry. Variables affecting the separation and preconcentration of lead and cadmium, such as the acidity of the aqueous solution, sample flow rate and volume, and eluent concentration and volume, were optimized. Under optimized condition, detection limits of the method for the determination of trace lead and cadmium in transgenic brown rice were 0.11 and 0.002 μg·L-1, respectively. The obtained results of lead and cadmium in the certified reference material (GBW10010, GBS1—1) were in good agreement with the certified values. The recoveries were in the range of 90%～103% and 93%～105% for detection of Pb and Cd in transgenic brown rice and the wild-type brown rice samples respectively. This study could provide technical support for determination of trace Pb and Cd in transgenic rice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 541 (2012)
Analysis of Atractylodes Macrocephala Koidz of Spaceflight Breeding with XRF and PXRD
DING Xi-feng, LIU Mei-yi, GUO Xi-hua, ZHU Yan-ying, WU Peng-le, and GUAN Ying
The contents of various elements in the fourth generation atractylodes macrocephala koidz cultivated by spaceflight breeding were analyzed and compared with those of the ground group on the whole jointly by XRF and PXRD. The results showed that the element Na and Ti could not be detected in the space group, and the levThe contents of various elements in the fourth generation atractylodes macrocephala koidz cultivated by spaceflight breeding were analyzed and compared with those of the ground group on the whole jointly by XRF and PXRD. The results showed that the element Na and Ti could not be detected in the space group, and the levels of K and Mn were enhanced by 1.16 and 1.15 times as these elements were measured in ground group, but other elements’ contents declined to different degrees, and the most notable elements are Si and P, decreasing by 82.1% and 71.2% accordingly; there is some whewellite in the ground group, whereas much less is found in the space group, The ground group contains inulin, however none in the space group. Spaceflight breeding can harvest significantly mutated specific Chinese herbal medicines varieties. The combination of two testing techniques has a positive role in space breeding applied in cultivation of medicinal plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 545 (2012)
A Review of Dyson Optical System in the Measure of Infrared Imaging Spectrum
LIU Yu-juan, TANG Yu-guo, Bayanheshig, CUI Ji-cheng, and QI Xiang-dong
It is difficult for the traditional infrared imaging spectrometers to satisfy the requirement of high signal to noise ratio(SNR) and small size simultaneously. The new infrared remote sensing imaging spectrometers based on Dyson concentric optical configuration have the advantages of high aperture, high SNR, simplenessIt is difficult for the traditional infrared imaging spectrometers to satisfy the requirement of high signal to noise ratio(SNR) and small size simultaneously. The new infrared remote sensing imaging spectrometers based on Dyson concentric optical configuration have the advantages of high aperture, high SNR, simpleness small volume and low weight. The Dyson imaging spectrometers can achieve high SNR, which is difficult for the traditional imaging spectrometers for infrared imaging spectrum. The present review introduces the beginning, the development and the present research of the Dyson imaging spectrometers, especially illustrates the principle of Dyson concentric spectrometer, difficulty during its manufacture and the application in the high-performance infrared remote sensing imaging spectrometers, providing a reference for the high-performance research of infrared remote sensing imaging spectrometers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 548 (2012)
Design of a Dual-Channel Mach-Zehnder Lateral Shearing Interferometer for the Large Aperture Static Imaging Spectrometer
FU Qiang, XIANGLI Bin, LV Qun-bo, and JING Juan-juan
Large aperture static imaging spectrometry (LASIS) is a kind of joint temporally and spatially modulated Fourier transform imaging spectrometry. In such instruments, lateral shearing interferometer is a key element, the most frequently used type of which is the Sagnac interferometer. In this configuration, one half of Large aperture static imaging spectrometry (LASIS) is a kind of joint temporally and spatially modulated Fourier transform imaging spectrometry. In such instruments, lateral shearing interferometer is a key element, the most frequently used type of which is the Sagnac interferometer. In this configuration, one half of the light entering the interferometer backtracks and causes a great decrease in energy efficiency. The present paper proposes a modified Mach-Zehnder lateral shearing interferometer structure to tackle this problem. With the ability to produce the same lateral shear, it features the advantage of dual channel output. We present a ray tracing procedure to induce the general expression of the lateral shear as well as analyze the contributions of error sources to the shear accuracy. The results serve as a new idea for the design of large aperture static imaging spectrometers and can be used to instruct the design and optimization of this kind of imaging spectrometer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 553 (2012)
Comparison of NO2 Slant Columns Between Two Ground-Based MAX-DOAS
XU Jin, XIE Pin-hua, SI Fu-qi, LI Ang, DOU Ke, LIU Wen-qing, Yugo Kanaya, and Hitoshi Irie
The study of comparison of NO2 SCD between two ground-based multi axis DOAS is introduced. The slant columns of NO2 from JAMASTEC are compared with those of AIOFM during the period from November to 31 December 2009. It says that the more signal to noise ratio is obtained by using the adjusted integral time rather than The study of comparison of NO2 SCD between two ground-based multi axis DOAS is introduced. The slant columns of NO2 from JAMASTEC are compared with those of AIOFM during the period from November to 31 December 2009. It says that the more signal to noise ratio is obtained by using the adjusted integral time rather than fixed settings; Two instrument show good accordance in the lower viewing angles, with the correlation coefficient of 0.995, but it becomes bad with higher viewing angles. The low deviation between the two instruments was achieved during the period from 9am to 17pm, the results in the 20 degree direction show best agreement with a deviation of 12%, but in other period the deviation becomes larger. The results in the visible range are better than those in the UV range, the residual in the fit decreases by more than 60%, and the results in the visible range show good agreements with those of AIOFM in the UV range during the whole day..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 558 (2012)
Optimization of Broad-Band Flat-Field Holographic Concave Grating without Astigmatism
KONG Peng, TANG Yu-guo, Bayanheshig, LI Wen-hao, and CUI Jin-jiang
The desirable imaging locations of the flat-field holographic concave gratings should be in a plane. And the object can be imaged perfectly by the grating when the tangential focal curve and sagittal focal curve both superpose the intersection of the image plane and dispersion plane. But actually, the defocus can not bThe desirable imaging locations of the flat-field holographic concave gratings should be in a plane. And the object can be imaged perfectly by the grating when the tangential focal curve and sagittal focal curve both superpose the intersection of the image plane and dispersion plane. But actually, the defocus can not be eliminated over the entire wavelength range, while the astigmatism vanishes when the grating parameters satisfy some conditions. An optimization method for broad-band flat-field holographic concave gratings with absolute astigmatism correction was proposed. The ray tracing software ZEMAX was used for investigating the imaging properties of the grating. And we made a comparison between spectral performance of gratings designed by this new method and that by conventional method, respectively. The results indicated that the spectral performance of gratings designed by using the absolute astigmatism correction method can be as good as gratings designed with the conventional method. And the focusing performance in the sagittal direction is much better, so that the S/N ratio can be greatly improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 565 (2012)
A Mobile Sensor for Remote Detection of Natural Gas Leakage
ZHANG Shuai, LIU Wen-qing, ZHANG Yu-jun, KAN Rui-feng, RUAN Jun, WANG Li-ming, YU Dian-qiang, DONG Jin-ting, HAN Xiao-lei, CUI Yi-ben, and LIU Jian-guo
The detection of natural gas pipeline leak becomes a significant issue for body security, environmental protection and security of state property. However, the leak detection is difficult, because of the pipeline’s covering many areas, operating conditions and complicated environment. A mobile sensor for remote detectiThe detection of natural gas pipeline leak becomes a significant issue for body security, environmental protection and security of state property. However, the leak detection is difficult, because of the pipeline’s covering many areas, operating conditions and complicated environment. A mobile sensor for remote detection of natural gas leakage based on scanning wavelength differential absorption spectroscopy (SWDAS) is introduced. The improved soft threshold wavelet denoising was proposed by analyzing the characteristics of reflection spectrum. And the results showed that the signal to noise ratio (SNR) was increased three times. When light intensity is 530 nA, the minimum remote sensitivity will be 80 ppm*m. A widely used SWDAS can make quantitative remote sensing of natural gas leak and locate the leak source precisely in a faster, safer and more intelligent way..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 570 (2012)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 2, 1 (2012)
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