Journals >Spectroscopy and Spectral Analysis
Contents
2011
Volume: 31 Issue 12
60 Article(s)
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Research Article
Preparation of Core-Shell Magnetic Nanoparticles and Its Application in Separation and Spectral Detection
CHEN Shuai, YAO Jian-lin, GUO Qing-hua, and GU Ren-ao
Magnetic nanoparticles as well as core-shell magnetic nanocomposites are of great interest for researchers due to their potential applications in lots of areas. In the present review, the authors summarized several universal synthetic methods of nanocomposites and their specific properties. In the following, the authorMagnetic nanoparticles as well as core-shell magnetic nanocomposites are of great interest for researchers due to their potential applications in lots of areas. In the present review, the authors summarized several universal synthetic methods of nanocomposites and their specific properties. In the following, the authors focused on the applications of functionalized magnetic nanoparticles in separation and spectral detection, along with the introduction of some work in the authors’ lab. At last, the questions remaining in magnetic nanoparticles and the application perspectives of magnetic nanocomposites were discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3169 (2011)
The Improvement of Bulk-Heterojunction Order in Polymer Photovoltaic Device
YUAN Dan, CHEN Zhi-jian, XIAO Li-xin, MU Li-ping, QU Bo, and GONG Qi-huang
The blend morphology and vertical arrangement are critical to the performance of organic bulk-heterojunction photovoltaic devices. In the present paper, the authors proposed a new annealing method that controls the blend morphology and vertical arrangement of two materials by means of simultaneously applying external eThe blend morphology and vertical arrangement are critical to the performance of organic bulk-heterojunction photovoltaic devices. In the present paper, the authors proposed a new annealing method that controls the blend morphology and vertical arrangement of two materials by means of simultaneously applying external electrical field and violet irradiation on the active layer of poly(3-hexylthiophene) (P3HT) and ［6,6］-phenyl C61-butyric acid methyl ester (PCBM) during annealing process. By using this annealing method, the power conversion efficiency increased by 36%, which was caused by vertical phased-separated blend of crystalline P3HT and PCBM and better charge extraction of electrodes. X-ray photoelectron spectroscopy (XPS) was measured to prove more fullerene derivatives at the organic/cathode interfaces by using this annealing method. The X-ray diffraction (XRD) analysis and UV-Vis absorption spectrum analysis also revealed more ordered polymer crystallization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3175 (2011)
Study of CH4 Spectroscopy at Low Temperature Near 1.65 μm
GAO Wei, WANG Gui-shi, CHEN Wei-dong, ZHANG Wei-jun, and GAO Xiao-ming
In the CH4 absorption spectroscopy measurement, especially the measurements at low temperature, the accurate values of the absorption spectral parameters are very important. The absorption spectral parameters are especially important when the authors use parameters to sense and model the atmospheres of the earth and thIn the CH4 absorption spectroscopy measurement, especially the measurements at low temperature, the accurate values of the absorption spectral parameters are very important. The absorption spectral parameters are especially important when the authors use parameters to sense and model the atmospheres of the earth and the outer planets. Sometimes the CH4 parameters listed in the HITRAN 2008 database are uncertain to some extent. In order to measure the low temperature absorption spectroscopy of methane, the authors used a cryogenic cell newly developed by ourselves in combination with a distributed feedback (DFB) diode laser as the light source and measured the low stated energy and the rotational angular momentum. And while the authors compared our data with HITRAN 2008, the authors modeled the line intensity changing with the temperature. The authors’ measured parameters will be helpful for sensing and modelling the atmospheres of the earth and the outer planets..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3180 (2011)
Preparation and Luminescent Performance of Tb3+ Doped SiO2 Core-Shell Nanoparticles
YAN Zhi-yun, HU Xiao-yun, YE Yan-xi, ZHANG De-kai, MIAO Hui, FAN Jun, and JIANG Zhen-yi
The authors synthesized the core-shell nanoparticles of SiO2-coated SiO2∶Tb3+ by using sol-gel method (SiO2∶Tb3+@SiO2), and studied the influence of core-shell ratio and preparation craftwork on its luminescence properties. The photograph of TEM and EDS showed that SiO2∶Tb3+ were coated successfully by SiO2. The authorThe authors synthesized the core-shell nanoparticles of SiO2-coated SiO2∶Tb3+ by using sol-gel method (SiO2∶Tb3+@SiO2), and studied the influence of core-shell ratio and preparation craftwork on its luminescence properties. The photograph of TEM and EDS showed that SiO2∶Tb3+ were coated successfully by SiO2. The authors found that the samples of SiO2∶Tb3+@SiO2 prepared by mixing of core and shell after shell aging with the ratio of core/shell being 1.2 g/25 mL had the stronger fluorescence intensity. Time-resolved spectra showed that the SiO2∶Tb3+@SiO2 had longer fluorescence life time than SiO2∶Tb3+..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3190 (2011)
Progress in Study of Biomacromolecular Damages by Infrared Spectroscopy
LI Li-li, ZHAO Li-jiao, and ZHONG Ru-gang
Infrared spectroscopy (IR) is employed as an important tool in the investigation of biological macromolecules because of its high sensitivity and nondestructivity to samples. When proteins, lipids or nucleic acids are damaged, the position, shape and intensity of their IR characteristic absorption peaks will be signifiInfrared spectroscopy (IR) is employed as an important tool in the investigation of biological macromolecules because of its high sensitivity and nondestructivity to samples. When proteins, lipids or nucleic acids are damaged, the position, shape and intensity of their IR characteristic absorption peaks will be significantly changed. This provides evidences for the determination of the damages of biomolecules, which further shed light on the clarification of the occurrence, development and early prevention of some diseases. In the present paper, the applications of IR to the detection of biomolecular damages are reviewed. Various IR techniques are introduced, including Fourier transform infrared spectroscopy (FTIR), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), Fourier transform infrared spectroscopy microscope and so on. A general review was performed for the application of IR technique to the qualitative and quantitative analysis of secondary structure of protein, fluidity of membrane lipid, interaction of drugs with DNA and so on. The existing problems of IR were pointed out and the prospect of IR technique in the field of biomedicine was discussed. It is expected that, in the future the researches involving IR techniques will be focused on the application in early diagnosis of diseases, instrumental combinations and quantitative techniques..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3194 (2011)
Review of Crop Residue Fractional Cover Monitoring with Remote Sensing
ZHANG Miao, LI Qiang-zi, MENG Ji-hua, and WU Bing-fang
Crop residue, as an important element of agro-ecosystem, can influence the flow of nutrients, carbon, water, and energy in agro-ecosystem. As a crucial indicator of distribution of crop residue, crop residue fractional cover is a key parameter of agro-ecosystem carbon cycle process model. Since remote sensing can easilCrop residue, as an important element of agro-ecosystem, can influence the flow of nutrients, carbon, water, and energy in agro-ecosystem. As a crucial indicator of distribution of crop residue, crop residue fractional cover is a key parameter of agro-ecosystem carbon cycle process model. Since remote sensing can easily obtain quantities of data, many researches were carried out on monitoring crop residue fractional cover with remote sensing. The present paper summarizes crop residue fractional cover estimation methods and latest progress in remote sensing, and these methods are classified into five categories according to the differences in methodologies and data sources. The principle of every method is described and compared. The advantages and shortages are also discussed and analyzed. Eventually, this paper points out some methods that should be improved, and presents the prospects of crop residue fractional cover estimation in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3200 (2011)
Terahertz Time-Domain Spectroscopy of Clenbuterol Hydrochloride
CHEN Xi-ai, HOU Di-bo, HUANG Ping-jie, KANG Xu-sheng, ZHANG Guang-xin, and ZHOU Ze-kui
The terahertz spectra of Clenbuterol hydrochloride in the range of 0.2 to 2.6 THz were obtained by THz time-domain spectroscopy, the absorption and refraction spectra of Clenbuterol hydrochloride was got meanwhile. The structure and vibrational frequencies of Clenbuterol molecule, Clenbuterol hydrochloride molecule andThe terahertz spectra of Clenbuterol hydrochloride in the range of 0.2 to 2.6 THz were obtained by THz time-domain spectroscopy, the absorption and refraction spectra of Clenbuterol hydrochloride was got meanwhile. The structure and vibrational frequencies of Clenbuterol molecule, Clenbuterol hydrochloride molecule and Clenbuterol hydrochloride crystal in the THz range were simulated. Based on the difference between experimental and theoretical results， the origin of the vibrational frequencies was analyzed. This study demonstrated the feasibility of time-domain terahertz spectroscopy for the identification of Clenbuterol hydrochloride and provides a new way for the detection of Clenbuterol hydrochloride..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3206 (2011)
Study on Spatial Distribution of Electron Energy in Hollowneedle-Plate Dielectric Barrier Discharge
DONG Li-fang, JI Ya-fei, and LI Yong-hui
In the present work, the spatial distributions of spectrum intensity of molecule and atom in the plasma generated in hollowneedle-plate discharge in atmosphere were measured, and the spatial distribution of electron energy in plasma was analyzed. A plasma about 3cm long is generated by using a hollowneedle-plate dischaIn the present work, the spatial distributions of spectrum intensity of molecule and atom in the plasma generated in hollowneedle-plate discharge in atmosphere were measured, and the spatial distribution of electron energy in plasma was analyzed. A plasma about 3cm long is generated by using a hollowneedle-plate discharge device. By collecting optical emission spectrum from 300 to 800 nm, it was found that the spectrum consists of strong ArⅠ lines, strong second positive band system of N2, and weak OⅠ line. The spatial distributions of spectrum intensity of ArⅠ（696.54， 763.51， 772.42, and 794.82 nm）, band N2（337.1， 357.6, and 380.4 nm）, and OⅠ 777.2 nm were measured. The ArⅠ lines decreased gradually from the arc root. The N2 lines increased gradually from the arc root and declined when they reached a maximum at 12 mm away from the arc root. The intensity of OⅠ increased from the arc root and declined when it reached a maximum at 6 mm away from the arc root. The spatial distribution of electron energy in plasma was analyzed qualitatively from the spatial distribution of spectrum intensity given above. It was found that the electrons located at 6 mm away from the arc root have high energy, while they have low energy at arc tip..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3210 (2011)
Spectroscopic Properties of Pr3+ Doped Transparent Oxyfluoride Vitroceramics
CHEN Ying, CHEN Xiao-bo, CHEN Luan, YANG Xiao-dong, HU Li-li, WU Zheng-long, YU Chun-lei, WANG Ya-fei, LIU Da-he, and TIAN Qiang
In the present paper, the room-temperature absorption spectrum of Pr3+-doped transparent oxyfluoride vitroceramics（Pr（0.2）∶FOV ）was studied systematically. The optical characterisation of Pr（0.2）∶FOV was performed. The standard and modified Judd-Ofelt theories were used to determine the J-O intensity parameters . The pIn the present paper, the room-temperature absorption spectrum of Pr3+-doped transparent oxyfluoride vitroceramics（Pr（0.2）∶FOV ）was studied systematically. The optical characterisation of Pr（0.2）∶FOV was performed. The standard and modified Judd-Ofelt theories were used to determine the J-O intensity parameters . The problems with standard Judd-Ofelt theorie for Pr3+ were discussed. Based on the intensity parameters, some predicted optical parameters, such as the spontaneous radiative transition probabilities, radiative lifetimes, branching ratios and integrated emission cross section were calculated. And the application of Pr∶FOV was analyzed. Especially there are large oscillator strength and large integrated emission cross section in the transitions of 3P0→3H4， 3P1→3H5 and 3P0→3H6， 3P0→3F2. So, they are more worth of attention. The obtained spectroscopic results show the potential application of the Pr3+-doped oxyfluoride vitroceramics for solid-state lasers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3213 (2011)
Synthesis and Luminescence Properties of Y10W2O21∶Eu Nanophosphor
SUN Li-nan, MENG Qing-yu, FENG Xiao-hui, ZUO Lin, YU Chen-hai, and MA Li
In the present paper, a novel nanophosphor, Y10W2O21∶Eu was synthesized through a simple and low-cost method: co-precipitation. The results of XRD show that resultant samples are Orthorhombic phase and primitive lattice. The average crystallographic sizes could be confirmed to be approximately 80 nm by means of the SchIn the present paper, a novel nanophosphor, Y10W2O21∶Eu was synthesized through a simple and low-cost method: co-precipitation. The results of XRD show that resultant samples are Orthorhombic phase and primitive lattice. The average crystallographic sizes could be confirmed to be approximately 80 nm by means of the Scherrer formula, which are in good agreement with the particles sizes exhibited by SEM. In the excitation spectra of Y10W2O21∶Eu nanophosphor, by monitoring 610 nm, the charge transfer bands (CTB) of O—Eu and O—W, centering at around 270 and 307 nm, can be observed, respectively. The spectral lines shape and locations of excitation peak corresponding to 4f→4f transitions are similar in all samples. But the relative intensity ratios between O—Eu and O—W CTB excitation peak increase with the Eu3+ doping concentration increasing. The characteristic red emission at around 610 nm of Eu3+ was also observed, ascribed to the 5D0→7F2 transition of Eu3+, and the optimal doping concentration is 20 mol%. Finally, the transition intensity parameters Ωλ(λ=2,4) and the quantum efficiencies of 5D0 level of Eu3+ were calculated according to Judd-Ofelt theory. The results indicate that Eu3+ 5D0→7F2 610 nm red luminescence can be effectively excited by 394 nm near-UV light and 464 nm blue light in Y10W2O21 host, which is similar to the familiar Eu3+ doped tungstate (e.g. Gd2(WO4)3, CaWO4). Therefore, the Y10W2O21∶Eu red nanophosphors may have a potential application for white LED..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3218 (2011)
Thermoluminescence Study on Sr2SiO4 Long Afterglow Material Doped with Eu2+
PENG Tie-qiu, WANG Yin-hai, LI Ya, and XIONG Yi
Sr1.97SiO4∶Eu2+0.03 phosphors were synthesized through the solid-state reaction technique. The X-ray diffraction shows that the phase of the phosphors is orthorhombic α′-Sr2SiO4. The produced phosphors show one intense emission band located at 490 nm. The phosphor shows a long afterglow properties excited by the sunligSr1.97SiO4∶Eu2+0.03 phosphors were synthesized through the solid-state reaction technique. The X-ray diffraction shows that the phase of the phosphors is orthorhombic α′-Sr2SiO4. The produced phosphors show one intense emission band located at 490 nm. The phosphor shows a long afterglow properties excited by the sunlight. The decay characteristics show that the phosphors consist of a quick decay process and a slow decay process. The experimental results demonstrate that the thermoluminescence (TL) curves of the samples containing four peaks, located at 346, 420, 457 and 552 K, respectively. Meanwhile, the different peaks show the different decay characteristics, and the electron transfer between the trap levels was measured..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3223 (2011)
Study on Building MLR Model Using Orthogonal Signal Correction
ZHANG Xian, YUAN Hong-fu, GUO Zheng, SONG Chun-feng, LI Xiao-yu, and XIE Jin-chun
MLR and PLS models with or without OSC were studied through establishing quantitative calibration models for the peanut oil content in blending edible oils, and for the dimethylsulfoxide concentration in water solution. The cross validation results and the predication results of MLR models, were compared to evaluate thMLR and PLS models with or without OSC were studied through establishing quantitative calibration models for the peanut oil content in blending edible oils, and for the dimethylsulfoxide concentration in water solution. The cross validation results and the predication results of MLR models, were compared to evaluate the effectiveness of OSC for improving the performance of MLR model. The results show that the SEC or SEP of MLR models using OSC gets smaller. Selecting appropriate wavelengths combination by CARS method, prediction capacity of MLR model using OSC is better than PLS1 model using raw spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3228 (2011)
Research on VOC Concentration Detection by Photoelastic Modulation Infrared Spectrum Absorption Method
HU Miao, WANG Tai-yong, QIAO Zhi-feng, GENG Bo, and XIAO Xin-hua
In order to ensure high stability and strong anti-interference ability in static interference system for qualitative and quantitative analysis of gas, a static scans interference detection system was designed based on photoelastic modulation infrared spectrum absorption system. The system consists of infrared laser, poIn order to ensure high stability and strong anti-interference ability in static interference system for qualitative and quantitative analysis of gas, a static scans interference detection system was designed based on photoelastic modulation infrared spectrum absorption system. The system consists of infrared laser, polarizer, photoelastic modulator, polarization analyzer and CCD components. By photoelastic modulator the principal refractive index of optical crystal will change cyclically by the modulation signal, producing cyclical changes in the optical path difference. With the calculation of modulation phase variation, the authors can get the function of the crystal length, the modulation cycle, and the range of optical path difference. Based on phase delay value and the energy distribution of interference pattern, the authors got the formula for the corresponding interference light intensity. The experiment used ZnSe crystal as the photoelastic modulation crystal, the polarizer uses the DOP3212 polarizer, and the detector uses the TCD5390AP array CCD. The five groups have different concentrations with three common VOC gases (formaldehyde, benzene and xylene) for detecting the concentrations of gases. The experimental results with the traditional infrared absorption were compared with the test results of photoelastic modulation infrared spectrum absorption method. The method of photoelastic modulation infrared spectrum absorption had high stability and real-time features, while the detection accuracy is better than the traditional infrared absorption method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3232 (2011)
Research on High-Precision Temperature Measurement System Based on Near Infrared Spectroscopy
ZHANG Yu-cun, QI Yan-de, and FU Xian-bin
At present, the interference from outside radiation under the complex environment is difficult to eliminate by using the infrared thermometry method. It leads to the low measurement accuracy. In the present paper, a high-precision infrared temperature measurement system was designed. The light filter method is presenteAt present, the interference from outside radiation under the complex environment is difficult to eliminate by using the infrared thermometry method. It leads to the low measurement accuracy. In the present paper, a high-precision infrared temperature measurement system was designed. The light filter method is presented in this system. The broadband filters and three-level interference filter were combined in this method. According to the method, the near-infrared spectra sent out by high temperature object is filtered. The high temperature background light and the environment obtrusive light are filtered out. In this way, two monochromatic spectra are obtained. The radiation power ratio is received after receiving by the infrared detector. Then the temperature is obtained by calculating. In this system, the bandwidth of monochromatic spectrum permeated is only 1 nm. The inhibition of radiation from background light and ambient light except transmittance spectrum is up to 8 orders of magnitude. The measurement error caused by the ambient temperature heating of the measured object is reduced. The accuracy of the temperature measurement system is improved. Finally, the temperature measurement system is feasible according to the experiment result. The precision reached to 0.2%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3236 (2011)
Study on Rapid Determination of Nutrient Composition in Corn Distillers Dried Grains with Solubles by Near-Infrared Reflectance Spectroscopy
ZHOU Liang-juan, ZHANG Li-ying, ZHANG En-xian, and SUI Lian-min
The possibility of using near-infrared reflectance spectroscopy (NIRS) for quantitative determination of 8 important nutrient compositions, including moisture, crude protein, ether extract, ash, total phosphorus, neutral detergent fiber, acid detergent fiber and crude fiber in corn DDGS was investigated in the present The possibility of using near-infrared reflectance spectroscopy (NIRS) for quantitative determination of 8 important nutrient compositions, including moisture, crude protein, ether extract, ash, total phosphorus, neutral detergent fiber, acid detergent fiber and crude fiber in corn DDGS was investigated in the present study. Ninety-three samples were collected from 18 plants in China over a three years period. Calibrations were performed by modified partial least squared algorithm and 15 different derivatives plus scatter correction spectral pretreatments. The results showed that the second derivative mathematical treatment gave the best prediction performance for most constituents. The prediction performance of models developed using 93 calibration samples was better than that developed using 70 samples. The coefficients of determination for calibration (RSQcal), coefficients of determination for cross-validation (1-VR), and RPDCV of cross-validation in models developed using 93 samples were 0.94～0.99, 0.89～0.99, and 2.98～14.85, respectively. These results indicate that NIRS can be used as a quantitative method for rapid determination of nutrient composition in corn DDGS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3241 (2011)
Study of Soil Organic Carbon Structural Change of Fallowing Grasslands by Synchrotron Radiation Spectrum Technology
LI Ting, ZHAO Shi-wei, MA Shuai, and LI Xiao-xiao
Synchrotron radiation soft X-ray and SR-FTIR spectroscopy technique were used to study the change of soil organic carbon(SOC) structure in ＜0.25 mm aggregate soil from fallowing grasslands of Yun-wu mountains. Results obtained by SR-FTIR technique were qualitatively analyzed, which indicated that compared with slope faSynchrotron radiation soft X-ray and SR-FTIR spectroscopy technique were used to study the change of soil organic carbon(SOC) structure in ＜0.25 mm aggregate soil from fallowing grasslands of Yun-wu mountains. Results obtained by SR-FTIR technique were qualitatively analyzed, which indicated that compared with slope farmland, the peak intensity of aliphatic-C from fallowing grasslands significantly increased, while peaks intensity of aromatic-C, alcohols-C, carboxyl-C, polysaccharide-C didn’t significantly change with increasing years of fallowing. Results obtained by SR-FTIR technique were semiquantitatively analyzed, which showed that compared with slope farmland, the relative content of functional groups from fallowing grasslands SOC was increased, the growing rate of aliphatic-C, alcohols-C in 0～5 cm and 10～20 cm soil horizon was greater than growing rate of aromatic-C. Results obtained by soft X-ray technique are consistent with SR-FTIR, and the relative content of the same functional groups (aliphatic-C, aromatic-C) gained by two determination methods were T-tested, which was not significant (P>0.05), indicating that using synchrotron radiation soft X-ray for the determination of SOC structural change of fallowing grasslands is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3245 (2011)
Application of NIR Spectroscopy to Estimate of MFA and Fiber Length of Neosinocalamus affinis
SUN Bai-ling, CHAI Yu-bo, HUANG An-min, and LIU Jun-liang
Near infrared spectroscopy was applied to rapidly predict microfibril angle (MFA) and fiber length of Neosinocalamus affinis Keng by using a fiber-optic probe in diffuse reflectance mode. The MFA and fiber length were measured by X-ray diffractometry and optical microscope, respectively. Partial least squares (PLS) wasNear infrared spectroscopy was applied to rapidly predict microfibril angle (MFA) and fiber length of Neosinocalamus affinis Keng by using a fiber-optic probe in diffuse reflectance mode. The MFA and fiber length were measured by X-ray diffractometry and optical microscope, respectively. Partial least squares (PLS) was used to build models based on raw and pretreated spectra, including noise spectra and noise combined with orthogonal signal correction (OSC) spectra. The results showed that the PLS models of MFA and fiber length, based on noise combined with OSC spectra, gave the strongest correlations, with correlation coefficient (R) of 0.893 6 and 0.988 3 and root mean standard error of prediction (RMSEP) of 0.292 0 and 0.146 0 in prediction set. The correlations between NIR predicted and MFA/fiber length actual values are very good. Therefore, it is concluded that MFA and fiber length of N. affinis can be estimated by NIR spectroscopy with sufficient accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3251 (2011)
Monitoring and Analysis of Urban Ozone Using Open Path Fourier Transform Infrared Spectrometry
LI Sheng, GAO Min-guang, ZHANG Yu-jun, LIU Wen-qing, XU Liang, TONG Jing-jing, CHENG Si-yang, JIN Ling, WEI Xiu-li, WANG Ya-ping, and CHEN Jun
An ozone monitoring system was developed by the method of open path Fourier transform infrared (OP-FTIR) spectrometry based on our FTIR spectrometer. In order to improve measurement precision and detection limit, the quantitative analysis was completed to get ozone concentration by combining synthetic background spectrAn ozone monitoring system was developed by the method of open path Fourier transform infrared (OP-FTIR) spectrometry based on our FTIR spectrometer. In order to improve measurement precision and detection limit, the quantitative analysis was completed to get ozone concentration by combining synthetic background spectrum method which uses information from HITRAN database and instrumental line shape, and nonlinear least squares (NLLSQ) method. The measurement methods for system detection limit were discussed and the result is 1.42 nmol·mol-1 with sixteen times averages. The authors developed continuous monitoring experiments in the suburban area of Hefei. For the day and month measurement results, the authors analyzed their variations with the generation sources. The result has shown that this system is reliable and precise and can be used as a new device and method for national ozone monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3256 (2011)
Detection of Benzoyl Peroxide in Wheat Flour by NIR Diffuse Reflectance Spectroscopy Technique
ZHANG Zhi-yong, LI Gang, LIU Hai-xue, LIN Ling, ZHANG Bao-ju, and WU Xiao-rong
Adding benzoyl peroxide (BPO) into wheat flour was prohibited by the relevant government departments since May 1，2011. And it is of great importance to detect BPO additive amount in wheat flour quickly and accurately. Part of BPO which was added into wheat flour will be deoxidized into benzoic acid, and this make it coAdding benzoyl peroxide (BPO) into wheat flour was prohibited by the relevant government departments since May 1，2011. And it is of great importance to detect BPO additive amount in wheat flour quickly and accurately. Part of BPO which was added into wheat flour will be deoxidized into benzoic acid, and this make it complex to detect the original BPO additive amount. The objective of the present research is to investigate the potential of NIR diffuse reflectance spectroscopy as a way for measurement of BPO original adding amount in wheat flour. A total of 133 wheat flour samples were prepared by adding different content of BPO into pure wheat flour. Spectra data were obtained by NIR spectrometer and then denoised by wavelet transform. Ninety seven samples were taken as calibration set and other 36 samples as prediction set. Partial least squares regression (PLSR) was applied to establish the calibration model between BPO original adding contents and the spectra data. The determination coefficient of model for the calibration set is 0.890 1, and root mean squared error of calibration (RMSEC) is 40.85 mg·kg-1. The determination coefficient for the prediction set is 0.886 5, and root mean squared error of prediction (RMSEP) is 44.69 mg·kg-1. The result indicates that it is feasible to detect the BPO adding contents in wheat flour by NIR diffuse reflectance spectroscopy technique and this technique has the potential to measure some other additives in food..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3260 (2011)
Rapid Diagnostics of Early Phosphorus Deficiency in Mini-Cucumber Plants under Protected Cultivation by Near Infrared Spectroscopy
SHI Ji-yong, ZOU Xiao-bo, ZHAO Jie-wen, MAO Han-ping, WANG Kai-liang, CHEN Zheng-wei, and HUANG Xiao-wei
The morphological symptom of phosphorus deficiency at early stage is similar to the appearance of leaf aging process in preliminary phase, so that visual diagnostics of phosphorus deficiency in mini-cucumber plants at early stage is practically impossible. Near infrared reflectance spectra contain information about difThe morphological symptom of phosphorus deficiency at early stage is similar to the appearance of leaf aging process in preliminary phase, so that visual diagnostics of phosphorus deficiency in mini-cucumber plants at early stage is practically impossible. Near infrared reflectance spectra contain information about differences in compositions of leaf tissues between phosphorus-deficient plants and healthy plants. In the present paper, near infrared reflectance spectroscopy was used to provide diagnostic information on phosphorus deficiency of mini-cucumber plants grown under non-soil conditions. Near infrared spectra was collected from 90 leaves of mini-cucumber plants. Raw cucumber spectra was preprocessed by SNV and divided into 27 intervals. The top 10 principal components (PCs) were extracted as the input of BP-ANN classifiers by principal component analysis (PCA) while the values of nutrient deficient were used as the output variables of BP-ANN and three layers BP-ANN discrimination model was built. The best experiment results were based on the top 3 principal components of No.7 interval when the spectra was divided into 27 intervals and identification rates of the ANN model are 100% in both training set and the prediction set. The overall results show that NIR spectroscopy combined with BP-ANN can be efficiently utilized for rapid and early diagnostics of phosphorus deficiency in mini-cucumber plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3264 (2011)
Study on Recognition of the True or False Red Wine Based on Visible-Near Infrared Spectroscopy
GUO Hai-xia, WANG Tao, LIU Yang, WU Hai-yun, ZUO Yue-ming, SONG Hai-yan, and HE Jin-yu
This study selected 90 samples from different brands of red wine. In order to eliminate the impact of spectral curve’s baseline, the first derivatives of all of spectral curves were calculated and the principal component analysis was carried out on the first derivative spectra. The result showed that the contribution rThis study selected 90 samples from different brands of red wine. In order to eliminate the impact of spectral curve’s baseline, the first derivatives of all of spectral curves were calculated and the principal component analysis was carried out on the first derivative spectra. The result showed that the contribution rate of the first two principal components was over 80 percent. By the first two principal components, all the red wine samples were obviously divided into two classes. Furthermore a 3-layer artificial neural network predictive model was built with the first four principal components as input variables and 100 percent correct prediction rate was gained. The research showed that the visible-near infrared spectroscopy combined with principal component analysis provides an accurate and reliable new method to rapidly and nondestructively recognize the true or false red wines..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3269 (2011)
Thymine on Silver Island Films: Surface-Enhanced Raman Scattering and Surface-Enhanced Infrared Absorption Studies
GUO Hao, BI Li-heng, DING Li, and MO Yu-jun
Thymine, being one of the four nucleobases in the nucleic acid of DNA, has received an increasing interest due to its potential importance in genetics and possible applications in medical science. In the present study, adsorption of thymine on laser-ablated silver island films was comparatively analyzed by means of surThymine, being one of the four nucleobases in the nucleic acid of DNA, has received an increasing interest due to its potential importance in genetics and possible applications in medical science. In the present study, adsorption of thymine on laser-ablated silver island films was comparatively analyzed by means of surface-enhanced Raman scattering (SERS) and surface-enhanced infrared absorption (SEIRA). Two new bands at 1 305 and 1 573 cm-1 appeared in the SERS spectrum of thymine on silver island films and represented that the molecule configuration of thymine hydrolyzed ion compound changed its structure from a keto form to an enol one. The greater enhancements of in-plane ring breath vibration bands and of 1 649 cm-1 band associated with C(4)O stretching vibration clearly suggested that the thymine molecules were adsorbed on the silver surface via O(8). The interaction of N(3) with silver surface could be inferred by the emergence of a stronger peak at 773 cm-1, which was assigned to the ring breath caused by the stretching vibration of the C(6)—N(3)—C(2). The blue shift of ring breath vibration from 749 to 773 cm-1 indicated that thymine ring should have some weak interaction with silver surface, i.e., there was a certain angle between the thymine ring and the silver surface. To sum up, the SERS spectrum indicated that thymine adsorbed on the silver surface as enolate through the O(8) and N(3) atoms. The molecular plane assumed a tilted orientation with respect to the silver surface. Laser-ablated silver island films also exhibited a good surface enhancement to infrared absorption for thymine. Enhancement factor was estimated to be about 200 under our experimental condition. There was no shift of C(2)O stretching vibration in SEIRA spectrum, revealing that O (7) was not involved in the adsorption process. Consistent with our SERS spectrum, the greater enhancement of the thymine ring deformation vibration (1 730 cm-1) in SEIRA agreed a tilted orientation of thymine on silver surface..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3273 (2011)
The Study of Several Aldehyde Molecules by Raman Spectroscopy
DONG Kun, RAO Zhi-fan, YANG Xiao-yun, LIN Jin-chang, and ZHANG Peng-xiang
The Raman spectra of formaldehyde, acetaldehyde, propionaldehyde and n-butyraladehyde （CnH2nO,n=1, 2, 3, 4） were obtained by portable Raman spectrometer. The molecules of the four aldehydes were calculated by density functional theory（DFT）. By comparing the calculated result and the experimental result, the bands of thThe Raman spectra of formaldehyde, acetaldehyde, propionaldehyde and n-butyraladehyde （CnH2nO,n=1, 2, 3, 4） were obtained by portable Raman spectrometer. The molecules of the four aldehydes were calculated by density functional theory（DFT）. By comparing the calculated result and the experimental result, the bands of these Raman spectra were assigned. And the Raman spectra of these aldehydes molecules were analyzed and compared. These aldehydes could be real-time rapidly identified by Raman spectroscopy technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3277 (2011)
Spectrum Diagnosis of Enhanced Arcjet Thruster Using Hydrazine Propellant
HOU Ling-yun, and JIA Yun-tao
A set of spectrum diagnostic system was established. With this system, spectrum analysis was carried out for the plume signal of enhanced arcjet thrust using catalytic decomposition products of hydrazine as propellant. Excitation plume temperatures for various wavelengths were obtained through measuring spectral radiatA set of spectrum diagnostic system was established. With this system, spectrum analysis was carried out for the plume signal of enhanced arcjet thrust using catalytic decomposition products of hydrazine as propellant. Excitation plume temperatures for various wavelengths were obtained through measuring spectral radiation intensity. The averaged excitation temperatures were analyzed based on Boltzman diagram. The results show that there is the highest temperature in the axial center of plume and the temperature drops quickly in the radial direction. The intensity of thermodynamic non-equilibrium weakens with a decrease in current and an increase in radial distance. The temperature of the plume rises with an increase in the proportion of ammonia in the catalytic decomposition mixture of hydrazine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3281 (2011)
Study on the Automatic Extraction Method of Spectral Data Features in Laser Induced Breakdown Spectroscopy
LIU Li-tuo, LIU Jian-guo, ZHAO Nan-jing, LU Cui-ping, CHEN Dong, SHI Huan, WANG Chun-long, ZHANG Yu-jun, and LIU Wen-qing
According to that the spectral line broadening of laser induced breakdown spectroscopy (LIBS) was lorentz nonlinear function model, using Levenberg-Marquardt(L-M) agorithm to optimally estimate the undetermined parameter in the function, the continuum background radiation and peak position and peak intensity were correAccording to that the spectral line broadening of laser induced breakdown spectroscopy (LIBS) was lorentz nonlinear function model, using Levenberg-Marquardt(L-M) agorithm to optimally estimate the undetermined parameter in the function, the continuum background radiation and peak position and peak intensity were corrected, and the method of data points automatic extraction for fitting was analysed. Automatic fitting and feature parameter extraction for spectral data of LIBS based on L-M algorithm that was hybrid programming with matrixVB and VB were accomplished,and the result was compared with the origin7.5 data analysis software which was manual and commonly used and verified its stability and reliability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3285 (2011)
Quantitative Analysis of Slag by Calibration-Free Laser-Induced Breakdown Spectroscopy
CHEN Xing-long, DONG Feng-zhong, WANG Qi, YU Rong-hua, LIANG Yun-xian, WANG Jing-ge, YANG Yang, NI Zhi-bo, XU Ming-ming, and WU Bian
Calibration-free laser induced breakdown spectroscopy (CF-LIBS) was employed for the quantitative analysis of slag. Nd∶YAG laser ablation was performed in air. The laser-induced plasma emission was measured by an Echelle spectrometer equipped with an ICCD. The plasma temperature and electron number density were determiCalibration-free laser induced breakdown spectroscopy (CF-LIBS) was employed for the quantitative analysis of slag. Nd∶YAG laser ablation was performed in air. The laser-induced plasma emission was measured by an Echelle spectrometer equipped with an ICCD. The plasma temperature and electron number density were determined from Boltzmann plots and a CaⅠ line width, respectively. The assumption of local thermal equilibrium was validated by the Ne criterion. The concentration of oxides was obtained from the concentration of elements by using stoichiometric relation. The calculated oxide concentrations were compared with those obtained by XRF. The relative errors of major elements were less than 15%. The results indicate that this method can be employed for the analysis of major elements in multi-component complex materials without certified reference..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3289 (2011)
Observation and Diagnostic of Ultraviolet Spectra in the Solar Transition Region
ZHANG Min, and WANG Dong
The solar transition region is the thin atmosphere layer between the chromosphere and corona. Although the thickness of the solar transition region is only several hundred kilometers, the parameters of the plasma change dramatically. The temperature increases from 104 to 106 K and the density drops from 1010 to 108 cm-The solar transition region is the thin atmosphere layer between the chromosphere and corona. Although the thickness of the solar transition region is only several hundred kilometers, the parameters of the plasma change dramatically. The temperature increases from 104 to 106 K and the density drops from 1010 to 108 cm-3. The emission of the solar transition region is generally of optical-thin far-ultraviolet (FUV) spectral lines, extreme-ultraviolet (EUV) spectral lines and background continuous spectral lines. However, the traditional ground-based observations can not be made for FUV/EUV lines, owing to their strong absorption by ozone and other molecules in the earth’s atmosphere. Thus, FUV/EUV lines only can be obtained with space-based observations. In recent decades, the successful launch of space-borne instruments opened a new era of the research for the solar transition region. The present paper reviews the observation history of ultraviolet spectra in the solar transition region and some kinds of space-borne instruments, especially several important spectrometers in recent ten years. At the same time, the diagnostics of the emissivity, electron density and electronic temperature of ultraviolet spectra in the solar transition region are expounded in detail. The shape of ultraviolet line is discussed and several important parameters with physical significance are showed using SOHO/SUMER spectrometer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3294 (2011)
Hydrothermal Synthesis, Crystal Structure and Luminescence Property of 3D Supermolecular Compound ［Zn(H2O)6］·(C16H8O8)
WANG Li-yuan, FAN Rui-qing, CHEN Hong, SUN Cun-fa, and YANG Yu-lin
A supermolecular compound ［Zn(H2O)6］·(C16H8O8)(1) was synthesized with 3,3′,4,4′- bipthenyltetracarboxylic acid (H4BPTC) and Zn(CH3COO)2·2H2O. Its structure was determined by single crystal X-ray diffraction, IR and element analysis. The crystal belongs to triclinic system with space group and the cell parameA supermolecular compound ［Zn(H2O)6］·(C16H8O8)(1) was synthesized with 3,3′,4,4′- bipthenyltetracarboxylic acid (H4BPTC) and Zn(CH3COO)2·2H2O. Its structure was determined by single crystal X-ray diffraction, IR and element analysis. The crystal belongs to triclinic system with space group and the cell parameters are: a=0.654 84(13) nm, b=0.793 88(16) nm, c=0.968 12(19) nm, α=76.29(3)°, β=87.75(3)°, γ=86.43(3)°, Z=1, R1=0.066 5, wR2=0.183 3, and GOF=1.021. We have studied the luminescence property of compound 1, The compound 1 has blue-purple luminescence in solutions of DMSO and green luminescence in the solid state at room temperature. In the solid state, the emission frequencies for complex 1 are red-shifted comparedwith their emission maximum peaks in solutions of DMSO. This red-shift of emission energy from solution to solid is likely to be caused by the intermolecular interaction in the solid state that effectively decreases the energy gap..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3298 (2011)
Fluorescence Fingerprint Transformation of Municipal Wastewater Caused by Aerobic Treatment
WU Jing, CUI Shuo, XIE Chao-bo, CAO Zhi-ping, CHEN Mao-fu, and L Yan-li
The conventional parameters such as COD and BOD only could represent information about total organic content. Fluorescence spectrum can display organic composition and it is unique for each sample, so it is referred as “fluorescence fingerprint”. In the present study transformation of excitation-emission matrix of muniThe conventional parameters such as COD and BOD only could represent information about total organic content. Fluorescence spectrum can display organic composition and it is unique for each sample, so it is referred as “fluorescence fingerprint”. In the present study transformation of excitation-emission matrix of municipal wastewater with sewage as major components after aerobic treatment was investigated and then the zones of biodegradable and non-biodegradable organic matters were figured out: the fluorescence at excitation wavelength/emission wavelength of about 280/340 nm and 225/240 nm derived from biodegradable organics and those of the zone of excitation wavelength above 300 nm and the zone of excitation wavelength below 300 nm and emission wavelength above 400 nm were mainly related with non-biodegradable organics. The above-mentioned results indicated that fluorescence fingerprint could be used to evaluate the performance and instruct design and operation of aerobic systems..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3302 (2011)
Fluorescence Spectra Analysis of Whey Protein Isolate-Dextran Conjugate
SUN Wei-wei, YU Shu-juan, YANG Xiao-quan, WANG Jin-mei, GUO Jian, and GUO Rui
The mixed whey protein isolate (WPI)-dextran was treated by dry-heating to prepare Maillard reaction products (MRPs), which was characterized by the browning. The free amino groups content significantly decreased by 35.77% and 30.53% in glycated protein samples, as the molecular weight of dextran increased from 67 to 1The mixed whey protein isolate (WPI)-dextran was treated by dry-heating to prepare Maillard reaction products (MRPs), which was characterized by the browning. The free amino groups content significantly decreased by 35.77% and 30.53% in glycated protein samples, as the molecular weight of dextran increased from 67 to 150 kD, respectively. This suggested that it was more difficult to be linked with WPI molecule when the chain length of dextran was increased. The characteristic of WPI-dextran conjugate was studied by fluorescence spectra in the paper. The maximum fluorescence intensity at 405 nm was obviously enhanced and G67 showed high fluorescence intensity than G150 over the wavelength range form 350 to 500 nm. This result revealed that the flourescent substance, a feature in Maillard reaction model system, was generated. As showed in the fluorescence spectra, the maximum fluorescence intensity at 470 nm was significantly decreased and the fluorescence intensity in each solution was in the order as follows: WPI>G150>G67. Moreover, the measurement of surface hydrophobicity index further showed that the hydrophobicity of WPI could be suppressed due to these two kinds of different molecular weight dextran..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3307 (2011)
Study of Photoluminesence Property of CdS/PAMAM Nanocomposites
JIN Yu-juan, LUO Yun-jun, XU Guo-zhi, and YANG Biao
The photoluminescence property of CdS/PAMAM nanocomposites in water at different ratio of Cd2+ to PAMAM(r) was studied by fluorescence emission spectrum, and the according mechanism was explored. The results indicate that in the irradiation of UV light at the wavelength of 330 nm, two peaks were shown in the fluorescenThe photoluminescence property of CdS/PAMAM nanocomposites in water at different ratio of Cd2+ to PAMAM(r) was studied by fluorescence emission spectrum, and the according mechanism was explored. The results indicate that in the irradiation of UV light at the wavelength of 330 nm, two peaks were shown in the fluorescence emission spectrum of CdS/PAMAM nanocomposites. One peak was attributed to PAMAM dendrimers, and the another came from CdS QDs. The strength of the frontier fluorescence emission peak became weaker and weaker, and at last disappeared with the enhancement of the ratio of Cd2+ to PAMAM; the strength of the latter fluorescence emission peak became stronger, which indicates that the electron at valence band of N atom in amines of dendrimers was transferred to CdS QDs. Oil latent finger marks deposited on transparent adhesive tapes surface treated with pure PAMAM solution with blue photoluminescence was not clear enough because of the blue light emitted from the impurity in adhesive tapes; Latent finger marks emitted strong yellow light and were successfully detected with good resolving rate with CdS/dendrimer solution with r of 10, which shows good reference value for detecting finger marks on surfaces with impurities emitting different photoluminescence colors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3311 (2011)
Synthesis and Spectra Characterization of Nano-Sized Ce1-x(Fe0.5La0.5)xO2-δ Solid Solutions
ZHANG Guo-fang, ZHANG Yang-huan, GE Qi-lu, ZHANG Yin, LIU Ling-sheng, and ZHANG Lian-lian
Ce1-x(Fe0.5La0.5)xO2-δ solid solutions were obtained via hydrothermal method. The structure of the solid solutions and the cell parameters were characterized by XRD analysis technique, the electron transition properties and doping effects were measured by UV-Vis diffraction spectrum and Raman spectrum technique. XRD reCe1-x(Fe0.5La0.5)xO2-δ solid solutions were obtained via hydrothermal method. The structure of the solid solutions and the cell parameters were characterized by XRD analysis technique, the electron transition properties and doping effects were measured by UV-Vis diffraction spectrum and Raman spectrum technique. XRD results showed that Ce1-x(Fe0.5La0.5)xO2-δ solid solutions exhibited cubic fluorite structure till the doping content increased to 0.30. Tiny Fe2O3 phase was observed when x=0.30. The particle size was kept nanoscaled, and location of different kind of doping ions in CeO2 lattice was discussed. By increasing the doping content, the cell parameter was kept increasing gradually till x=0.18, then it remained almost constant. The UV-Vis diffraction spectrum analysis showed that the absorption threshold edge redshifted, the band gap energy decreased with increasing the doping content. The valence of Fe ions in the lattice of CeO2 was +3. The F2g Raman mode also showed a downshift, and the peak gradually became broader, which further proved the influence of the dopant..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3315 (2011)
Effect of S-Configuration Transformation on the Microstructure of Ovalbumin
HUANG Qun, MA Mei-hu, CAI Zhao-xia, LUO Zhang, HUANG Xi, and SUN Shu-guo
The effect of S-configuration transformation on the microstructure of ovalbumin was studied by CD spectra, XRD spectra, ANS fluorescence probe emission spectra and UV absorption spectra. CD spectra was used to examine the changes in the secondary structure of the ovalbumin during S-ovalbumin information process. When tThe effect of S-configuration transformation on the microstructure of ovalbumin was studied by CD spectra, XRD spectra, ANS fluorescence probe emission spectra and UV absorption spectra. CD spectra was used to examine the changes in the secondary structure of the ovalbumin during S-ovalbumin information process. When the induction time was prolonged, the mutual transformation between α-helix, β-sheet, β-turn and the random coil was observed, and the orderliness of the secondary structure was increased with α-helix decreasing slightly and β-sheet increasing correspondingly. XRD spectra analysis showed that the crystal structure content of the ovalbumin increased with prolonging the induction time and the largest data was observed at 72 h, indicating that the orderliness of the secondary structure was increased. The results were similar to CD spectra analysis. The ANS fluorescence probe emission spectra analysis demonstrated that S-configuration transformation induced an increase in surface hydrophobicity with prolonging the induction time, and the largest data was also observed at 72 h. In addition, UV absorption spectra analysis indicated that S-configuration transformation resulted in a decrease in the UV-absorption maximum value with prolonging the induction time, indicating that the aromatic amino acid was buried in the molecular interior. The results indicated that the changes in the microstructure of ovalbumin were relevant to S-configuration transformation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3319 (2011)
Handbook of X-ray Photoelectron Spectroscopy. Minnesota: Perkin-Elmer Corporation Press, 1979. 91. Spectroscopic Study of Photocatalytic Mechanism of Methanol and CO2
HAI Feng, ZHANG Qian-cheng, BAI Feng-rong, WANG A-nan, WANG Zhi-wei, and JIAN Li
Ni-Ti-O/SiO2 catalyst was prepared by impregnation method, and its photocatalytic performance for carbonylation of methanol with CO2 was investigated under UV light. The in-situ IR, XPS and MS were carried out to analyze the possible photocatalytic reaction mechanism. Results indicated that the Ni-Ti-O/SiO2 exhibited gNi-Ti-O/SiO2 catalyst was prepared by impregnation method, and its photocatalytic performance for carbonylation of methanol with CO2 was investigated under UV light. The in-situ IR, XPS and MS were carried out to analyze the possible photocatalytic reaction mechanism. Results indicated that the Ni-Ti-O/SiO2 exhibited good photocatalytic performance for carbonylation of methanol with CO2, the methanol conversion reached up to 24.9%, and the selectivity for the carbonylated products was more than 60% within 180 min reaction time. The catalyst characterization results showed that the OC·O- and CH3OC(O)· might be important intermediate in the carbonylation of methanol with CO2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3323 (2011)
Identification of Invoice Based on Laser-Induced Photoluminescence Spectrum
YANG Qin, YANG Yong, and TIAN Yong-hong
The rapid identification of invoice authenticity was studied based on laser-induced photoluminescence spectrum. First, the spectral curves of eighty invoice samples were obtained by laser-induced photoluminescence detection system, and genetic algorithm (GA) was applied to fit and separate overlapped spectral region beThe rapid identification of invoice authenticity was studied based on laser-induced photoluminescence spectrum. First, the spectral curves of eighty invoice samples were obtained by laser-induced photoluminescence detection system, and genetic algorithm (GA) was applied to fit and separate overlapped spectral region between 566 and 669 nm by three Gaussian peaks. Spectral feature parameters extracted by GA were employed as the inputs of BP neural networks, and then an identification model was built. One hundred and four data were converted to 13 Gaussian parameters, and for authentic and false invoices the coefficients of determination (R2) were 0.997 89 and 0.996 83 and the relative standard deviations (RSD) were 0.017 052 and 0.022 362, respectively. It was showed that Gaussian fitting algorithm could not only simplify the parameters of models, but also improve the explanation of analysis models. Through comparison analysis of the results, it was found that the model, whose thirteen feature parameters and two evaluated parameters were all applied as BP inputs, was the best, and the corrected identification rates of sixty calibration samples and twenty validation samples were both 100％. So the identification method studied in the present research played a good role in the classification and identification, and offered a new approach to the rapid identification of invoice authenticity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3328 (2011)
Research on Detecting Trace Formaldehyde Gas by the Multi-Wavelengths Characteristics Method
LI Yang-jun, and WANG Gao
In order to overcome the slow speed of detecting trace formaldehyde in the sample gas, material consumption by chemical reaction, and the limitations of the sampling area in the detection of trace formaldehyde, a multi-wavelength characteristics method for getting the exact concentration of formaldehyde quickly was desIn order to overcome the slow speed of detecting trace formaldehyde in the sample gas, material consumption by chemical reaction, and the limitations of the sampling area in the detection of trace formaldehyde, a multi-wavelength characteristics method for getting the exact concentration of formaldehyde quickly was designed. According to the spectrum characteristics of formaldehyde and the main interfering gases the system chose multiple wavelengths with the minimum degree of coherence (the number of characteristic wavelengths were selected to be 3, 4 and 5), in conjunction with the corresponding groups of narrow-band filters. With the infrared light of the light source through the chamber windows and narrow-band filters, the infrared light was collected by the PCI-2TE-13 infrared detectors, and the concentration of formaldehyde in the sample gas was calculated by the characteristics spectrum absorption algorithm. In the experiments, the system analyzed and calculated the concentration of formaldehyde in four gas samples collected in the newly renovated house, building materials market, supermarkets and outdoor parks. Experimental results of the system and test results of ARCSpectro-AMIR infrared spectrometer were compared, the results show that test data above 10 mg·m-3 were close to true value by the multi-wavelengths characteristics method, and the average error is less than 5%. So the system meets the requirements of practical applications, and it has the advantages of real-time detection, not poisoning so on..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3332 (2011)
Response Characteristics of the Field-Measured Spectrum for the Four Gerneral Types of Halophyte and Species Recognition in the Northern Slope Area of Tianshan Mountain in Xinjiang
ZHANG Fang, XIONG Hei-gang, Nurbay Abdusalih, and LUAN Fu-ming
Based on the field-measured Vis-NIR reflectance of four common types of halophyte (Achnatherum splendens(Trin.)Nevski, Sophora alopecuroides L., Camphorosma monspeliaca L.subsp.lessingii（L.）Aellen, Alhagi sparsifolia shap) within given spots in the Northern Slope Area of Tianshan Mountain in Xinjiang, the spectral respBased on the field-measured Vis-NIR reflectance of four common types of halophyte (Achnatherum splendens(Trin.)Nevski, Sophora alopecuroides L., Camphorosma monspeliaca L.subsp.lessingii（L.）Aellen, Alhagi sparsifolia shap) within given spots in the Northern Slope Area of Tianshan Mountain in Xinjiang, the spectral response characteristics and species recognition of these types of halophyte were analyzed. The results showed that (Alhagi sparsifolia shap) had higher chlorophyll and carotenoid by CARI and SIPI index. (Sophora alopecuroides L. was at a vigorously growing state and had a higher NDVI compared with the other three types of halophyte because of its greater canopy density. But its CARI and SIPI values were lower due to the influence of its flowers. (Sophora alopecuroides L.) and (Camphorosma monspeliaca L.subsp.lessingii(L.)) had stable REPs and BEPs, but REPs and BEPs of (Achnatherum splendens(Trin.)Nevski, Aellen, Alhagi sparsifolia shap) whose spectra red shift and spectra blue shift occurred concurrently obviously changed . There was little difference in spectral curves among the four types of halophyte, so the spectrum mixing phenomenon was severe. (Camphorosma monspeliaca L.subsp.lessingii（L.）Aellen) and (Alhagi sparsifolia shap) could not be separated exactly in a usual R/NIR feature space in remote sensing. Using the stepwise discriminant analysis, five indices were selected to establish the discriminant model, and the model accuracy was discussed using the validated sample group. The total accuracy of the discriminant model was above 92% and (Achnatherum splendens(Trin.)Nevski) and (Camphorosma monspeliaca L.subsp.lessingii（L.）Aellen) could be respectively recognized 100% correctly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3336 (2011)
Effect of Different Snow Depth and Area on the Snow Cover Retrieval Using Remote Sensing Data
JIANG Hong-bo, QIN Qi-ming, ZHANG Ning, DONG Heng, and CHEN Chao
For the needs of snow cover monitoring using multi-source remote sensing data, in the present article, based on the spectrum analysis of different depth and area of snow, the effect of snow depth on the results of snow cover retrieval using normalized difference snow index (NDSI) is discussed. Meanwhile, taking the HJ-For the needs of snow cover monitoring using multi-source remote sensing data, in the present article, based on the spectrum analysis of different depth and area of snow, the effect of snow depth on the results of snow cover retrieval using normalized difference snow index (NDSI) is discussed. Meanwhile, taking the HJ-1B and MODIS remote sensing data as an example, the snow area effect on the snow cover monitoring is also studied. The results show that: the difference of snow depth does not contribute to the retrieval results, while the snow area affects the results of retrieval to some extents because of the constraints of spatial resolution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3342 (2011)
Hyperspectral Acquisition System for Tongue Inspection Based on X-Y Scanning Galvanometer
LI Gang, ZHAO Jing, LIN Ling, and ZHANG Bao-ju
Hyperspectral was used for tongue inspection in the present work to resolve the problem that information of current research for tongue inspection was inadequate. A hyperspectral acquisition system based on X-Y scanning galvanometer was also proposed due to the high cost of the current hyperspectral apparatus. An experHyperspectral was used for tongue inspection in the present work to resolve the problem that information of current research for tongue inspection was inadequate. A hyperspectral acquisition system based on X-Y scanning galvanometer was also proposed due to the high cost of the current hyperspectral apparatus. An experiment was made to test the ability of this system. By collecting the hyperspectral information of color pictures with size similar to the tongue, the results of experiment showed that this system can acquire more information of tongue than other methods, and this method can provide a new way for tongue inspection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3347 (2011)
Validation of Feasibility of Virtual Hyperspectral Technology
LIN Ling, WU Hong-jie, LI Zhe, LI Gang, ZHANG Bao-ju, and WU Jin-cheng
To verify the virtual hyperspectral technology for acquiring the internal composition and structure information, the virtual hyperspectral system, which took apples as the test materials, was built . First, we detected the virtual hyperspectral system of the normal apples and ill apples. Then, the virtual hyperspectralTo verify the virtual hyperspectral technology for acquiring the internal composition and structure information, the virtual hyperspectral system, which took apples as the test materials, was built . First, we detected the virtual hyperspectral system of the normal apples and ill apples. Then, the virtual hyperspectral of apple slices and apple slices with a piece of red optical filter embedded was detected. Finally, the reflection spectrum of normal apple, ill apple, apple slice and slice with a piece of red filter embedded was detected. The results showed that virtual hyperspectral, which can gain more information than reflection spectrum, could be used for detecting the variation of internal composition and structure. It is a strong evidence that this technology can be used in human body in the future. Virtual hpyerspectral is a new path applied to detecting the biological information, and it can be used for the multi-information and cross-information detection simultaneously and systematically. More foundation for quick disease check-up in vivo was expected to be provided by this technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3352 (2011)
Microanalysis Study on Lignin Distribution of Wood with Different Growth Stress Level by SEM-EDXA
LIU Xiao-li, YIN Ya-fang, JIANG Xiao-mei, and BIAN Ming-ming
By virtue of FE-SEM and EDXA marked by Br element, the relationship between the lignin distribution and growth stress was micro-analyzed by normal wood of plantation Eucalyptus urophylla×E. grandis with different growth stress levels. The results indicated that the lignin contents of different cell wall layers werBy virtue of FE-SEM and EDXA marked by Br element, the relationship between the lignin distribution and growth stress was micro-analyzed by normal wood of plantation Eucalyptus urophylla×E. grandis with different growth stress levels. The results indicated that the lignin contents of different cell wall layers were not related to the growth stress level, and the lignin content (from high level to low level) in sequence was cell corner, compound middle lamellae, S1, S2 and S3; The lignin contents in micro-morphological regions of wood fiber cell wall were decreased with the increase in growth stress and lignification process was delayed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3358 (2011)
Preparation and Characterization of Quantum Dots with Polyacrylic Acid Modified Method in Water-Soluble Core-Shell Structure
ZHAO Bin, ZHAO Su-qing, CAI Yan-fei, PENG Wei, ZHANG Kun, and LIU Duan
Cd-Zn quantum dots (QDs) modified with thiourea was firstly prepared asthe cores, then the cores were coated with polyacrylic acid with PVP K-30 as the stabilizer in water-soluble reaction system. The water-soluble fluorescence QDs were the same size and stable. The water-soluble QDs were characterized by fluorescence Cd-Zn quantum dots (QDs) modified with thiourea was firstly prepared asthe cores, then the cores were coated with polyacrylic acid with PVP K-30 as the stabilizer in water-soluble reaction system. The water-soluble fluorescence QDs were the same size and stable. The water-soluble QDs were characterized by fluorescence emission spectra, infrared spectra (IR), and transmission electron microscopy（TEM）. The effects of the nuclear QDs with different concentration under polyacrylic acid solution on the optical properties of QDs were also studied. The results showed that the nanoparticles of QDs modified with polyacrylic acid have more uniform particle distribution, and the main peak was blueshifted from 548 to 448 nm. CO and C—O stretching vibration absorption peaks were 2 092.8 and 1 384.3 cm-1 in infrared spectra, amide bond of CO stretching vibration absorption peaks were 1 644.5 cm-1. The best concentration of nuclear QDs under polyacrylic acid solution was 2.67 mg·mL-1. QDs prepared by this simple method have good stability and strong fluorescence intensity. The approach introduced in this paper will lay a solid foundation for biological markers and applications of QDs in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3362 (2011)
Determination of Metal by Liquid Electrode Discharge Atomic Emission Spectrometry with a New Design
YANG Ya-qin, WANG Hong-mei, CHU Yan-nan, and HAN Hai-yan
A liquid electrode discharge atomic emission spectrometry has been developed with a new design. Plasma fluctuation from the variations in the gap between the W anode and liquid cathode was eliminated by providing a sawtooth-shaped drainage structure. The sawtooth was placed at a distance of 2 mm from the glass capillarA liquid electrode discharge atomic emission spectrometry has been developed with a new design. Plasma fluctuation from the variations in the gap between the W anode and liquid cathode was eliminated by providing a sawtooth-shaped drainage structure. The sawtooth was placed at a distance of 2 mm from the glass capillary top. When a solution is pumped through a glass capillary, the liquid drop forms and rises and on reaching the maximum size collapses while the next drop forms. This results in a continuous change in the interelectrode distance which will cause the discharge current to change, plasma flickers and is extinguished. With the new design, the surface tension of the drop was destroyed before its growing up, and the solution was flowing along the drainage groove. The discharge can last for 3 hours at least with such arrangement. The analytical response curves for lead, chromium, cadmium, zinc, vanadium, nickel, copper, silver and cobalt demonstrated good linearity. The limit of detections of lead, chromium, cadmium, zinc, vanadium nickel, copper, silver and cobalt were determined to be 0.08, 0.61, 0.48, 1.60, 10.88, 0.48, 0.084, 0.048 and 0.27 mg·L-1 respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3366 (2011)
Distribution Characteristics of Heavy Metals along an Elevation Gradient of Montane Forest
WAN Jia-rong, NIE Ming, ZOU Qin, HU Shao-chang, and CHEN Jia-kuan
In the present paper, the concentrations of fourteen heavy metals (Fe, Al, Ti , Cu, Cr, Mn, V, Zn, Ni, Co, Pb, Se, Cd and As) were determined by ICP-AES and atomic absorption spectroscopy along an elevation gradient of montane forest. The results show that the elevation gradient had significant effects on the concentraIn the present paper, the concentrations of fourteen heavy metals (Fe, Al, Ti , Cu, Cr, Mn, V, Zn, Ni, Co, Pb, Se, Cd and As) were determined by ICP-AES and atomic absorption spectroscopy along an elevation gradient of montane forest. The results show that the elevation gradient had significant effects on the concentrations of Fe, Al, Ti, V, Pb and As. And the concentrations of Cu, Cr, Mn, Zn, Ni, Co, Se and Cd were not significantly affected by the elevation gradient. Because the studying area is red soil, the elevation gradient had significant effects on the concentrations of Fe, Al and Ti which are characteristic heavy metals of red soil, suggesting that the red soil at different elevations has different intensities of weathering desilication and bioaccumulation. Other heavy metals have different relationships with the elevation gradient, such as the concentrations of Cr, Zn and Cd were high at relatively high elevation and Pb and As were high at relatively low elevation. These results suggest that the different elevations of montane forest soils were polluted by differently types of heavy metals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3371 (2011)
Determination of Trace Nickel in Bi-Based Superconductor Powder by Inductively Coupled Plasma Atomic Emission Spectroscopy after Separation with Anion Exchange Resin and Extraction with Methylbenzene
FAN Li-xin, LI Jian-qiang, FAN Hui-li, SUN Jian-ling, ZHANG Xia, BAO Rui, LU Qing, and WANG Jie
A new method for the determination of trace nickel 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 in the superconductor powdeA new method for the determination of trace nickel 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 in the superconductor powder was serious when the amount of matrix increased, and the repeatability as well as the accuracy was poor, so it was necessary to used separation and preconcentration to improve the accuracy and precision. In this experiment, Ni-diacetyl dioxime complexes were enriched by toluene extraction in alkaline condition after eliminating the interference of major element Bi and partial Pb, Sr, Ca and Cu by eluting with anion exchange resin, then the Ni-complexes were back extracted by diluted hydrochloric acid. The enrichment conditions were investigated in detail and the recovery rate of Ni was higher than 95%. Under the optimal condition, an artificial sample was analysed, the result showed that the found values were identical with reference values, and the RSD and detection limit were 1.9% and 0.19 μg·g-1, respectively. The method has been applied to the determination of trace nickel in Bi-based superconductor powder samples with satisfactory results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3375 (2011)
Quantitative Determination of Elements in Plant Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry
WANG Qi, ZHANG Wen, WANG Li-yun, LIU Yong-sheng, HU Sheng-hong, and HU Zhao-chu
The 193 nm excimer laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used for the quantification of 13 elements (Li, B, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Ni, Cu and Ba) in the plant samples (GBW070602, GBW070605 and GBW08514). Indium standard solution with known concentration was mixed into samplThe 193 nm excimer laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used for the quantification of 13 elements (Li, B, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Ni, Cu and Ba) in the plant samples (GBW070602, GBW070605 and GBW08514). Indium standard solution with known concentration was mixed into samples and used as an internal standard. Afterwards the samples were ground again and pressed to disks. NIST SRM 610 glass material reference standard was used as the external standard in the LA-ICP-MS measurements. In contrast to longer wavelength ablation techniques, in this experiment a round crater with low deposits could be achieved during ablation. And another study was done on the effect of homogenization over the powder disk. It was clearly shown that the analytical results under the condition of 193 nm LA-ICP-MS, using NIST SRM 610 as the external standard for analysis of pressed disk of plant sample, are in good agreement with certified values..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3379 (2011)
Two Steps Elution Method FI On-Line Adsorption and Preconcentration Coupled with FAAS for the Determination of Trace Zinc
WANG Zhong-yuan, ZHANG Hong-kang, FANG Hong-da, SU Yao-dong, and Gauri S. Mittal
A flow injection two steps elution method on-line sorption and preconcentration system coupled to flame atomic absorption spectrometry (FAAS) was developed for the determination of trace Zn in water samples. The conventional elution procedure was divided into two steps: elution procedure and detection procedure. DuringA flow injection two steps elution method on-line sorption and preconcentration system coupled to flame atomic absorption spectrometry (FAAS) was developed for the determination of trace Zn in water samples. The conventional elution procedure was divided into two steps: elution procedure and detection procedure. During the elution procedure, the eluent was pumped into KR by the suction of the peristaltic pump and through PTFE tube instead of peristaltic pump tube. By the new method, the dispersion of the analyte was decreased notably, and high absorbance peak value was achieved. Because the eluent was not through the peristaltic pump tube, the peristaltic pump tube was protected from being eroded. Emptying procedure was added in order to insure the veracity and repeatability of the experiment of every time. With 60 s (sample throughput of 37·h-1) of sampling at a flow rate of 6.0 mL·min-1, an enhancement factor (EF) of 28 (higher than 9 achieved by conventional elution method) and a detection limit (3σ) of 0.35 μg·L-1 were obtained. The precision (RSD, n=11) was 2.1% at the 20 μg·L-1 level. When 0.1 ‰φ triethannolamine was used as masking reagent, the recovery rate was from 98.7% to 99.6%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3384 (2011)
Determination of Aluminum in Wheat Flour Food by Microwave Digestion-High Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry
REN Ting, ZHAO Li-jiao, and ZHONG Ru-gang
The contents of aluminum (Al) in four kinds of wheat flour food (noodle, dumpling wrapper, twisted cruller and soda biscuit) were determined by high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) combined with microwave digestion. The samples were completely digested by the miThe contents of aluminum (Al) in four kinds of wheat flour food (noodle, dumpling wrapper, twisted cruller and soda biscuit) were determined by high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) combined with microwave digestion. The samples were completely digested by the mixture of HNO3 and H2O2 in closed polytetrafluoroethylene (PTFE) vessels. The conditions for microwave digestion, pyrolysis temperature and atomization temperature were optimized. The optimum experimental conditions were determined as follows. The microwave digestion was performed with HNO3/H2O2 7∶1 (volume ratio), microwave power 1 000 W and 190 ℃ for 40 minutes. The optimum pyrolysis temperature was 1 350 ℃ and the optimum atomization temperature was 2 400 ℃. Magnesium nitrate solution with the concentration of 1 g·L-1 was used as the matrix modifier. The correlation coefficient for the standard curve was 0.9999, the relative standard deviation (RSD) was from 1.7% to 2.4%, and the recovery for the samples was from 98.16% to 102.67%. The assay method for the determination of Al in wheat flour food established in this study has referential importance for the constituent of the correlated food standards..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3388 (2011)
Investigation on Urinary Arsenic Concentration of City Children in China
XIN Hua, XU Fang, and ZHOU Wei
Children’s urine sample was digested with nitric acid and drop-wise added hydrogen peroxide. After pre-reduction with ascorbic acid-thiourea, the total arsenic in sample solution was formed arsine in a flow injection hydride generation system and then was detected by atomic fluorescence spectrometry. Calibration curve Children’s urine sample was digested with nitric acid and drop-wise added hydrogen peroxide. After pre-reduction with ascorbic acid-thiourea, the total arsenic in sample solution was formed arsine in a flow injection hydride generation system and then was detected by atomic fluorescence spectrometry. Calibration curve was established every day and blank correction should be made for each analysis. Detection limit was 0.03 μg·L-1. Analytical results of urine arsenic for 40 children sampling from Minhang District, Shanghai, were in the range of 0.5～1.5 μg·L-1, possibly due to the foodstuffs of seafood and is not harmful to the human health..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3392 (2011)
Nondestructive Analysis of a Liuli Ring of Warring State Period by EDXRF Probe
LI Qing-lin, YU Xi-yun, LING Xue, and YAO Zheng-quan
A Liuli ring was nondestructively analyzed by EDXRF probe, to discuss the characteristic of chemical composition and the producing place of this Liuli ring. The result reveals that the chemical composition of this Liuli ring belongs to PbO-BaO-SiO2 system, which is similar to Chinese special ancient PbO-BaO-SiO2 glass A Liuli ring was nondestructively analyzed by EDXRF probe, to discuss the characteristic of chemical composition and the producing place of this Liuli ring. The result reveals that the chemical composition of this Liuli ring belongs to PbO-BaO-SiO2 system, which is similar to Chinese special ancient PbO-BaO-SiO2 glass dating from Chunqiu to East Han state. So, it was concluded that this Liuli ring was used Chinese special technology and formula, and was made in China. But on the appearance, this Liuli ring is not like a mature glass, but a faience or frit which is the compound of glass and crystal substance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3395 (2011)
A Fractal Denoising Method for Astronomical Spectral Signal
HAN Jin-shu, LUO A-li, and ZHAO Yong-heng
To restore the continuum and the spectral lines from a noisy astronomical spectrum, then to measure the equivalent widths of the spectral lines, the fractal denoising method was firstly used in astronomical spectra in the present paper. The method is based on the distinguishing features, that is the local self-similariTo restore the continuum and the spectral lines from a noisy astronomical spectrum, then to measure the equivalent widths of the spectral lines, the fractal denoising method was firstly used in astronomical spectra in the present paper. The method is based on the distinguishing features, that is the local self-similarities exist in an astronomical spectrum, while not in a random white noise signal. The experimental results show that the fractal denoising method is efficient in parameter measurements, such as equivalent widths for spectral lines, redshift of galaxies, and so on. In addition, the method can achieve data compression. The fractal method can be used in the mass spectra of LAMOST..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3399 (2011)
Study of Instrumental Line Shape function of High-Resolution Fourier Transform Infrared Spectrometer with Unequal Field of View
REN Li-bing, WEI Hao-yun, ZHANG Ya, and LI Yan
Field Of View (FOV) is an important contributor for instrumental line shape (ILS) function of high-resolution Fourier transform infrared spectrometer (FTS) only next to maximum optical difference. For the reason of optical design and layout, commonly, the measured FOV located in detector is not regularly rounded as oriField Of View (FOV) is an important contributor for instrumental line shape (ILS) function of high-resolution Fourier transform infrared spectrometer (FTS) only next to maximum optical difference. For the reason of optical design and layout, commonly, the measured FOV located in detector is not regularly rounded as original one. There exits more or less difference between the measured vertical FOV and measured horizontal one. In view of this case, the present paper replaces the generally circular area light source with an elliptical one, which is probably more suitable for actual FTS. At the same time, the factor maximum optical difference was considered. After these, the mathematic and graphic description about ILS function with unequal field of view （UFOV） was given. Finally, comparison between measured spectrum with standard monoxide gas and calculated one with equal field of view (EFOV) and UFOV respectively was taken. Experimental results show that the spectral residual from UFOV is less fluctuant than those from EFOV and its root mean square value is the smallest. All these indicate that the ILS function from UFOV is more accurate and suited to reflecting the response of high-resolution FTS than the one from EFOV..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3403 (2011)
Analysis of Influence of Satellite Platform Vibration on Spectral Imaging Quality of Dispersive Imaging Spectrometer
WANG Xiao-yan, TANG Yi, TANG Qiu-yan, WANG Jing, and NI Guo-qiang
Satellite platform vibrations make dispersive imaging spectrometer and objects generate relative movement in exposure time, which seriously affects the quality of spectral data. PHI was made as the model of dispersive spectrometer, the impact of pitch, roll, yaw and three-axis vibrations on spectral data were studied cSatellite platform vibrations make dispersive imaging spectrometer and objects generate relative movement in exposure time, which seriously affects the quality of spectral data. PHI was made as the model of dispersive spectrometer, the impact of pitch, roll, yaw and three-axis vibrations on spectral data were studied chiefly, and distorted spectral data cubes under various vibrations were simulated, then the general law of distortion spectral cube caused by satellite platform vibration was gained. The results show that the dispersive imaging spectrometer has high requirements for reduction of vibration amplitude, A small amplitude also can generate great influence on spectrum. The spectral data must be corrected and the vibration of satellite platform must be reduced to ensure the authenticity of spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3407 (2011)
The Optimizing Design and Experiment for a MOEMS Micro-Mirror Spectrometer
MO Xiang-xia, WEN Zhi-yu, ZHANG Zhi-hai, and GUO Yuan-jun
A MOEMS micro-mirror spectrometer, which uses micro-mirror as a light switch so that spectrum can be detected by a single detector, has the advantages of transforming DC into AC, applying Hadamard transform optics without additional template, high pixel resolution and low cost. In this spectrometer, the vital problem iA MOEMS micro-mirror spectrometer, which uses micro-mirror as a light switch so that spectrum can be detected by a single detector, has the advantages of transforming DC into AC, applying Hadamard transform optics without additional template, high pixel resolution and low cost. In this spectrometer, the vital problem is the conflict between the scales of slit and the light intensity. Hence, in order to improve the resolution of this spectrometer, the present paper gives the analysis of the new effects caused by micro structure, and optimal values of the key factors. Firstly, the effects of diffraction limitation, spatial sample rate and curved slit image on the resolution of the spectrum were proposed. Then, the results were simulated; the key values were tested on the micro mirror spectrometer. Finally, taking all these three effects into account, this micro system was optimized. With a scale of 70 mm×130 mm, decreasing the height of the image at the plane of micro mirror can not diminish the influence of curved slit image in the spectrum; under the demand of spatial sample rate, the resolution must be twice over the pixel resolution; only if the width of the slit is 1.818 μm and the pixel resolution is 2.278 6 μm can the spectrometer have the best performance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3412 (2011)
Design and Study of a High Resolution Vacuum Ultraviolet Imaging Spectrometer Carried by Satellite
YU Lei, LIN Guan-yu, QU Yi, WANG Shu-rong, and WANG Long-qi
A high resolution vacuum ultraviolet imaging spectrometer prototype carried by satellite applied to the atmosphere detection of particles distribution in 115～300 nm was developed for remote sensing. First, based on the analysis of advanced loads, the optical system including an off-axis parabolic mirror as the telescopA high resolution vacuum ultraviolet imaging spectrometer prototype carried by satellite applied to the atmosphere detection of particles distribution in 115～300 nm was developed for remote sensing. First, based on the analysis of advanced loads, the optical system including an off-axis parabolic mirror as the telescope and Czerny-Turner structure as the imaging spectrometer was chosen. Secondly, the 2-D photon counting detector with MCP was adopted for the characteristic that the radiation is weak in vacuum ultraviolet waveband. Then the geometric method and 1st order differential calculation were introduced to improve the disadvantages that aberrations in the traditional structure can not be corrected homogeneously to achieve perfect broadband imaging based on the aberration theory. At last, an advanced example was designed. The simulation and calculation of results demonstrate that the modulation transfer function (MTF) of total field of view is more than 0.6 in the broadband, and the spectral resolution is 1.23 nm. The structure is convenient and predominant. It proves that the design is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3417 (2011)
Influence of Surface Roughness on Degree of Polarization of Biotite Plagioclase Gneiss Varying with Viewing Angle
XIANG Yun, YAN Lei, ZHAO Yun-sheng, GOU Zhi-yang, and CHEN Wei
Polarized reflectance is influenced by such factors as its physical and chemical properties, the viewing geometry composed of light incident zenith, viewing zenith and viewing azimuth relative to light incidence, surface roughness and texture, surface density, detection wavelengths, polarization phase angle and so on. Polarized reflectance is influenced by such factors as its physical and chemical properties, the viewing geometry composed of light incident zenith, viewing zenith and viewing azimuth relative to light incidence, surface roughness and texture, surface density, detection wavelengths, polarization phase angle and so on. In the present paper, the influence of surface roughness on the degree of polarization (DOP) of biotite plagioclase gneiss varying with viewing angle was inquired and analyzed quantitatively. The polarized spectra were measured by ASD FS3 spectrometer on the goniometer located in Northeast Normal University. When the incident zenith angle was fixed at 50°, it was showed that on the rock surfaces with different roughness, in the specular reflection direction, the DOP spectrum within 350~2 500 nm increased to the highest value first, and then began to decline varying with viewing zenith angle from 0° to 80°. The characterized band (520±10) nm was picked out for further analysis. The correlation analysis between the peak DOP value of zenith and surface roughness showed that they are in a power function relationship, with the regression equation: y=0.604x-0.297, R2=0.985 4. The correlation model of the angle where the peak is in and the surface roughness is y=3.419 4x+51.584, y<90°, R2=0.817 7. With the detecting azimuth farther away from 180° azimuth where the maximum DOP exists, the DOP lowers gradually and tends to 0. In the detection azimuth 180°, the correlation analysis between the peak values of DOP on the (520±10) nm band for five rocks and their surface roughness indicates a power function, with the regression equation being y=0.582 2x-0.333, R2=0.984 3. F tests of the above regression models indicate that the peak value and its corresponding viewing angle correlate much with surface roughness. The study provides a theoretical base for polarization remote sensing, and impels the rock and city architecture discrimination and minerals mapping..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3423 (2011)
Spectral Line Shift Property of Prism Dispersive Imaging Spectrometer
ZHANG Jun-qiang, YAN Chang-xiang, ZHENG Yu-quan, and WU Qing-wen
In order to study the spectral line shift property of prism-dispersive imaging spectrometer, the influencing factors and mechanisms of spectral line shift were presented, and the mathematical model based on linear optics model was established to describe the spectral line shift property. Code V API functions was used, In order to study the spectral line shift property of prism-dispersive imaging spectrometer, the influencing factors and mechanisms of spectral line shift were presented, and the mathematical model based on linear optics model was established to describe the spectral line shift property. Code V API functions was used, in Matlab environment, to verify the validity of mathematical model, and the sensitivity coefficient of spectral line shift was analyzed. Results indicate that rigid body motion of optical mirror surface generated by environmental variation is the key causation of spectral line shift. When the decenter of mirror surface is no more than 0.2 mm and the tilt is less than 0.02°, the value of spectral line shift of different wavelengths at different fields is equivalent, and the error is less than 0.1 pixel. Spectral line shift due to mirror rigid body motion is linear and independent, and the total shift of the spectral line is the algebraic sum of values produced by the single freedom of motion (DOF) of single mirror surface. The mathematical model based on linear optics model can be used to study the spectral line shift property of the prism-dispersive imaging spectrometer. It will provide some guidance for spectral calibration and spectral property analysis under complex work condition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3429 (2011)
The Influence of Laser Plasma Effects on the Characteristics of Silicon Surface Damage
FAN Wei-xing, HAN Jing-hua, LI Hai-bo, YANG Li-ming, FENG Guo-ying, GAO Xiang, LIU Yan-yan, BAO Ling-dong, and HUANG Yong-zhong
Silicon is the basic material for electro-photonic detectors, so the studies of the laser induced damage of silicon are of great significance in laser detecting and military applications. The damage characters of silicon under high intensity nanosecond laser pulses were investigated in the present paper. The results shSilicon is the basic material for electro-photonic detectors, so the studies of the laser induced damage of silicon are of great significance in laser detecting and military applications. The damage characters of silicon under high intensity nanosecond laser pulses were investigated in the present paper. The results show that laser plasma has thermal effect, shock effect and spectral radiation effect, etc. These comprehensive effects combined together determinate the damage characters. By thermal effects and shock effects of laser plasma, the material is being melt, vaporized, ionized and pushed out at the laser irradiated area. In this way, the pit can be formed and the cooled ejected effluents are radially distributed. The silicon was melt at the bottom of the pit and the temperature was modulated by the intensity of the incident laser, which interfered with scattering laser simultaneously. The periodic heat distribution generates the period stripes. N, O and Si characteristic spectrum in the laser plasma prove that the colored film is the mixture of SiOx∶SiNy which were sprayed out from laser plasma under repetitive laser pulses..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3815 (2011)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 1 (2011)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 12, 3434 (2011)
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