Journals >Spectroscopy and Spectral Analysis
Contents
2012
Volume: 32 Issue 11
60 Article(s)
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Research Article
Spectral Calibration for Space-Borne Differential Optical Absorption Spectrometer
ZHOU Hai-jin, LIU Wen-qing, SI Fu-qi, ZHAO Min-jie, JIANG Yu, and XUE Hui
Space-borne differential optical absorption spectrometer is used for remote sensing of atmospheric trace gas global distribution. This instrument acquires high accuracy UV/Vis radiation scattered or reflected by air or earth surface, and can monitor distribution and variation of trace gases based on differential opticaSpace-borne differential optical absorption spectrometer is used for remote sensing of atmospheric trace gas global distribution. This instrument acquires high accuracy UV/Vis radiation scattered or reflected by air or earth surface, and can monitor distribution and variation of trace gases based on differential optical absorption spectrum algorithm. Spectral calibration is the premise and base of quantification of remote sensing data of the instrument, and the precision of calibration directly decides the level of development and application of the instrument. Considering the characteristic of large field, wide wavelength range, high spatial and spectral resolution of the space-borne differential optical absorption spectrometer, a spectral calibration method is presented, a calibration device was built, the equation of spectral calibration was calculated through peak searching and regression analysis, and finally the full field spectral calibration of the instrument was realized. The precision of spectral calibration was verified with Fraunhofer lines of solar light.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2881 (2012)
Research on the Influence of LED Temperature Shifts on Differential Optical Absorption Spectroscopy for Measuring NO2
LING Liu-yi, XIE Pin-hua, QIN Min, ZHENG Ni-na, YE Cong-lei, LI Ang, and HU Ren-zhi
Influences of LEDs (without etalon structure and center wavelengths are respectively 370 nm(near-UV), 452 nm(blue) and 660 nm(red)) temperature shifts on differential optical absorption spectroscopy(DOAS) for measuring NO2 were studied. NO2 absorption spectra were formed using LED emitting spectra at 10 ℃. The measuredInfluences of LEDs (without etalon structure and center wavelengths are respectively 370 nm(near-UV), 452 nm(blue) and 660 nm(red)) temperature shifts on differential optical absorption spectroscopy(DOAS) for measuring NO2 were studied. NO2 absorption spectra were formed using LED emitting spectra at 10 ℃. The measured LED spectra at other temperatures were used as reference spectra of DOAS. Thus, NO2 differential optical densities under different LED temperature shifts were acquired and then NO2 differential cross-sections were fitted to the acquired differential optical densities. From fitting results, the linear relations of 0.995, 0.945 and 0.989 correlation between delta of fitting residual and near-UV, blue and red LEDs temperature shifts were found and their slopes are respectively 1.12×10-3, 5.25×10-5 and 7.45×10-4 ℃-1. The fitting results show that the influence of temperature shifts of blue LED on DOAS retrieval is negligible and the temperature shifts of near-UV and red LED are impressible to DOAS measurement resulting in degradation of detection sensitivity. The retrieval results of blue LED with and without etalon with similar temperature properties were compared and showed that etalon of LED will greatly increase the influence of temperature shifts of LED on DOAS retrieval..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2886 (2012)
The Reconstruction of Two-Dimensional Distributions of Gas Concentration in the Flat Flame Based on Tunable Laser Absorption Spectroscopy
JIANG Zhi-shen, WANG Fei, XING Da-wei, XU Ting, YAN Jian-hua, and CEN Ke-fa
The experimental method by using the tunable diode laser absorption spectroscopy combined with the model and algorithm was studied to reconstruct the two-dimensional distribution of gas concentration. The feasibility of the reconstruction program was verified by numerical simulation. A diagnostic system consisting of 2The experimental method by using the tunable diode laser absorption spectroscopy combined with the model and algorithm was studied to reconstruct the two-dimensional distribution of gas concentration. The feasibility of the reconstruction program was verified by numerical simulation. A diagnostic system consisting of 24 lasers was built for the measurement of H2O in the methane/air premixed flame. The two-dimensional distribution of H2O concentration in the flame was reconstructed, showing that the reconstruction results reflect the real two-dimensional distribution of H2O concentration in the flame. This diagnostic scheme provides a promising solution for combustion control..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2891 (2012)
Measurement of OH Radicals in Flame with XeCl Excimer Laser
LIU Yu, LIU Wen-qing, KAN Rui-feng, SI Fu-qi, XU Zhen-yu, HU Ren-zhi, and XIE Pin-hua
The present paper describes how to measure OH radicals in the flame of alcohol burner flame by using XeCl excimer laser. The instrument consists of a XeCl excimer laser as light source, a multiple-reflection cell with whole path length of light achieving 2 560 meters, and a double pass high resolution echelle spectromeThe present paper describes how to measure OH radicals in the flame of alcohol burner flame by using XeCl excimer laser. The instrument consists of a XeCl excimer laser as light source, a multiple-reflection cell with whole path length of light achieving 2 560 meters, and a double pass high resolution echelle spectrometer with resolution 3.3 pm. This paper describes the reason for using the XeCl excimer laser without spectral etaloning and how to get rid of the water in reactor chamber. The results of the experiment get some absorption peak of OH radicals from 308.145 to 308.175 nm. By choosing the appropriate fit area and fitting, the results contrast with the measure data by using Xe lamp as light source..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2897 (2012)
Vibrational to Rotational Energy Transfer between CsH(X1Σ+,v≥15) and CO2
DAI Kang, WANG Shu-ying, LIU Jing, and SHEN Yi-fan
The quenching of highly vibrational excited CsH through collisions with a 500 K bath of CO2 was investigated using the laser spectroscopy technique. CsH was formed by the Cs(7P)+H2 reaction. The pulse laser prepared CsH in the highly vibrational levels. Laser induced fluorescence was used to detect collisionally relaxeThe quenching of highly vibrational excited CsH through collisions with a 500 K bath of CO2 was investigated using the laser spectroscopy technique. CsH was formed by the Cs(7P)+H2 reaction. The pulse laser prepared CsH in the highly vibrational levels. Laser induced fluorescence was used to detect collisionally relaxed CsH. The relaxation rate coefficient of CsH(v″=21) with CO2 is 10 times larger than that of CsH(v″=15). Relaxation of CsH(v″) with H2 was also investigated. The mass effect on the collisional relaxation rate coefficients is strong. The observed collisional relaxation rate coefficients of H2 are bigger than those of CO2. Energy gain into CO2 resulting from collisions with excited CsH was probed using laser overtone spectroscopy technique. Distributions of nascent CO2 rotational population in the ground (0000) state were determined. For CsH excited at v″=15, the scattered CO2 molecules have a rotational temperature of Trot=(605±50) K. For excitation at v″=21, the CO2 rotational temperature is Trot=(780±70) K. Based on the rotational temperatures, the average change in the CO2 rotational energy 〈ΔErot〉 has a stronger dependence on the CsH initial energy. Using the ambient cell temperature, 〈ΔErot〉v″=21～2.7〈ΔErot〉v″=15 was found. The nascent distributions of recoil velocities for collisions were determined from stimulated absorption line profiles of individual CO2 rotational states. For v″=15, scattered CO2 molecules with J=36-48 have center of mass translational energy of 〈Erel〉=600～972 cm-1. For v″=21, the values increase to 〈Erel〉=972～1 351 cm-1. Based on propensity rules for collisions that favor small changes in energy and angular momentum, it is reasonable that low-J CO2 states will have lower translational energy than the high-J states. Extrapolating v″=15 and 21 data to the initial relative translational energy of E0=520 cm-1 gives an estimate of the threshold states Jth=34 and 24, respectively. The onset of large 〈Erel〉 is likely to occur at J states that are larger than Jth..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2902 (2012)
Study on Mechanism of Ionic Liquid for Methane Plasma Conversion Using Spectra Method
ZHANG Xiu-ling, ZHOU Qian, DI Lan-bo, and YU Miao
C6MIMBF4, C6MIMCF3COO and C6MIMHSO4 were introduced into a direct current discharge plasma system respectively for methane conversion. The kinds of active species and relative intensity of spectral peaks were detected via online spectrum diagnosis technique of optical emission spectroscopy. Mechanism of ionic liquid foC6MIMBF4, C6MIMCF3COO and C6MIMHSO4 were introduced into a direct current discharge plasma system respectively for methane conversion. The kinds of active species and relative intensity of spectral peaks were detected via online spectrum diagnosis technique of optical emission spectroscopy. Mechanism of ionic liquid for methane conversion in gas-liquid plasma was investigated. The results showed that a spatially and temporally stable gas-liquid interface was obtained in ionic liquid incorporated plasma system. With introduction of ionic liquid, methane conversion and C2 hydrocarbons yields increased. The C2 hydrocarbon selectivity greatly increased when C6MIMCF3COO and C6MIMBF4 were introduced to the plasma, and decreased when C6MIMHSO4 was used. Active species like C, C2, C3, CH and H were detected in gas-liquid plasma system of methane discharge. Compared with the absence of ionic liquid in the plasma system, the relative intensity of spectral peaks of most active species increased when ionic liquid was introduced into the plasma system. 1H NMR results showed that the structure of ionic liquid kept stable during plasma discharge progress. Those indicated that ionic liquid could improve the plasma discharge intensity. At the same time, ionic liquid showed good catalytic activity in gas-liquid surface reaction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2906 (2012)
Review of Normal Spectral Emissivity Standard Reference Materials
YU Kun, LIU Yu-fang, and ZHAO Yue-jin
In order to improve the accuracy of spectral emissivity measurement, standard reference materials of spectral emissivity as the dissemination of quantity in spectral emissivity measurement are used for the calibration of spectral emissivity measurement apparatus. In the present paper, firstly the standard reference matIn order to improve the accuracy of spectral emissivity measurement, standard reference materials of spectral emissivity as the dissemination of quantity in spectral emissivity measurement are used for the calibration of spectral emissivity measurement apparatus. In the present paper, firstly the standard reference materials data proposed by the American National Institute of Standards and Technology are introduced, and some underlying standard reference materials suggested by some metering departments in Europe are analyzed in detail. For the standard reference material Armco iron and SiC proposed by some researchers, the advantages and disadvantages were explored. Finally, the characteristics of standard reference materials are summarized, and the future development of spectral emissivity measurement standard is prospected..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2911 (2012)
Effects of Laser Shot Frequency on Plasma Radiation Characteristics
CHEN Jin-zhong, BAI Jin-ning, SONG Guang-ju, SUN Jiang, DENG Ze-chao, and WANG Ying-long
To improve the quality of laser-induced breakdown spectroscopy, nanosecond pulse laser generated by Nd∶YAG laser was used to excite soil sample. The intensity and signal-to-background ratio of Al Ⅰ 394.401 nm, Ba Ⅰ 455.403 nm, Fe Ⅰ 430.791 nm and Ti Ⅰ 498.173 nm were observed using a grating spectrometer and a photoeleTo improve the quality of laser-induced breakdown spectroscopy, nanosecond pulse laser generated by Nd∶YAG laser was used to excite soil sample. The intensity and signal-to-background ratio of Al Ⅰ 394.401 nm, Ba Ⅰ 455.403 nm, Fe Ⅰ 430.791 nm and Ti Ⅰ 498.173 nm were observed using a grating spectrometer and a photoelectric detection system. The effects of laser shot frequency（5, 10 and 15 Hz）on the radiation characteristics of laser-induced plasma was studied. The experimental results show that as compared with the laser shot frequency of 5 Hz, the spectral line intensity of Al, Ba, Fe and Ti increased by about 50.94%, 112.7%, 107.46%, and 99.38% at 15 Hz respectively under the same laser energy, while the spectral signal-to-background ratio increased byabout 15.16%, 24.08%, 40.26% and 72.06% respectively. The effects mechanism of the laser shot frequency on radiation characteristics of plasma is explained by measuring plasma parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2916 (2012)
Multi-Spectral Measurement of Basic Oxygen Furnace Flame Temperature
WANG Yong-qing, CHEN Yan-ru, ZHAO Qi, CHEN Fei-nan, and CHEN Jing-jing
A multi-wavelength analysis method is introduced to measure the temperature of basic oxygen furnace flame. In this study, USB4000 spectrometer was applied to obtain radiation spectrum of flame within wavelength range 200~1 100 nm, from which the flame temperature and monochromatic emissivity was derived by Levenberg-MaA multi-wavelength analysis method is introduced to measure the temperature of basic oxygen furnace flame. In this study, USB4000 spectrometer was applied to obtain radiation spectrum of flame within wavelength range 200~1 100 nm, from which the flame temperature and monochromatic emissivity was derived by Levenberg-Marquart modeling method. Wavelet neural network was applied to process the spectral measurement data, which could cancel the assumption model of emissivity and wavelengths. It is a kind of valid method to acquire the true temperature and spectral emissivity. Each neuron in the hidden layer of a feed-forward network is a combination of the sigmoidal activation function (SAF) and morlet wavelet activation function (WAF). The output of the hidden neuron is the product of the output from these two activation functions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2920 (2012)
Determination of Parameter Range in Detecting Cu of Gannan Navel Orange by LIBS Setup
LIN Yong-zeng, YAO Ming-yin, LIU Mu-hua, PENG Qiu-mei, ZHANG Xu, CHEN Tian-bing, and XU Yuan
In order to improve the precision and sensitivity of laser-induced breakdown spectroscopy device on detecting heavy metal, parameter optimization should be done. After selecting the initial delay time parameter in detecting navel orange experiment of laser-induced breakdown spectroscopy device, a cell range from 1.10 tIn order to improve the precision and sensitivity of laser-induced breakdown spectroscopy device on detecting heavy metal, parameter optimization should be done. After selecting the initial delay time parameter in detecting navel orange experiment of laser-induced breakdown spectroscopy device, a cell range from 1.10 to 1.30 μs of delay time containing the initial parameter was extracted and experiment on it was conducted. There are more than one peak in the curve of element line intensity and signal-to-background ratio vs the delay time in the cell range, and the peak values are higher than the initial one. Confidence interval of the delay time calculated indirectly by interval estimation in Statistics is (1.13, 1.25］. The relative standard deviation decreases from 0.103 269 548 to 0.025 322 279 5 when the delay time adjusted from 1.20 to 1.14 μs in the confidence interval. It is suggested that parameters range of LIBS experimental device can be adjusted freely in the range while detecting measured elements so as to improve the precision and sensitivity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2925 (2012)
Surface Plasmon Resonance Spectral Based Fiber Optic Sensor for Detection of Total Dissolved Solids in Water Quality Analysis
FENG Li-hang, ZENG Jie, LIANG Da-kai, and LIU Hong-yue
As surface plasmon resonance (SPR) spectrum is sensitive to refractive index of the mediums, we explored its sensitivity characteristic of ions composition detection in a solution so as to measure the total dissolved solid value in water. Seven ionic (NaCl, KCl, CaCl2, MgCl2, Na2CO3, MgSO4 and ZnSO4) and 3 non-ionic (gAs surface plasmon resonance (SPR) spectrum is sensitive to refractive index of the mediums, we explored its sensitivity characteristic of ions composition detection in a solution so as to measure the total dissolved solid value in water. Seven ionic (NaCl, KCl, CaCl2, MgCl2, Na2CO3, MgSO4 and ZnSO4) and 3 non-ionic (glucose, glycerol and sucrose) liquid samples were studied experimentally with a fiber optic SPR sensor. The influence of ion concentration on the resonance wavelength shift in SPR spectrum was investigated and discussed, and with that, the response curves were established to realize the detection of total dissolved solid in water quality analysis. The FO-SPR sensor spectral curve for TDS measurement was in conformity with ionic conductivity in 8 different water samples, and results show that the spectral method was better in high ion concentration detection of water. This research will broaden the SPR application in the field of water quality monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2929 (2012)
Photoluminescence of Silver Nanoparticles
WANG Yue-hui, SHEN Jian-hong, LI Na-jing, JIN Fan, and HE Qiang
In the present paper, the photoluminescence of silver nanoparticles with different size and surface modifier was studied. The results show that the strong emission peak at 362 nm and the two weak emission peaks at 592 and 725 nm respectively were observed by excitation at different wavelengths. With increasing excitatiIn the present paper, the photoluminescence of silver nanoparticles with different size and surface modifier was studied. The results show that the strong emission peak at 362 nm and the two weak emission peaks at 592 and 725 nm respectively were observed by excitation at different wavelengths. With increasing excitation wavelength, the intensity of emission peak decreased and the emission peak at 362 nm red-shifted. Otherwise, the photoluminescence of silver nanoparticles was sensitive to the excitation light of 210 nm. The emission peak has little relation with the surface modification and particle size of silver nanoparticles, just as the particle size decreased, the intensity of peak decreased. The intensity of emission peak decreased with the slit width decreased. The emission peaks gradually gathered together and merged into single peak at 426 nm, and the intensity first increased and then decreased. The mechanism of photoluminescence of silver nanoparticles was discussed by absorption-reemission of photoelectrons and interface energy hybridization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2935 (2012)
Research Progress in Using Functional Near-Infrared Spectroscopy for Monitoring Depth of Anesthesia
HONG Wen-xue, ZHANG Zhong-peng, SONG Jia-lin, LI Shao-xiong, LUAN Jing-min, CHEN Ning, and TAN Jian-qiang
Intra-operation monitoring depth of anesthesia is an important method to insure the quality and safety of clinical anesthesia. As a noninvasive brain function monitoring technology, functional near-infrared spectroscopy can provide objective and reliable brain activity monitoring and imaging in real time. The characterIntra-operation monitoring depth of anesthesia is an important method to insure the quality and safety of clinical anesthesia. As a noninvasive brain function monitoring technology, functional near-infrared spectroscopy can provide objective and reliable brain activity monitoring and imaging in real time. The characteristic of this technique is highly suitable for interrelated research on depth of anesthesia monitoring. The present paper briefly introduced the fundamental and instruments of functional near-infrared spectroscopy, reviewed the current situation about the application of functional near-infrared spectroscopy in research on depth of anesthesia monitoring, pointed out the possible way of using functional near-infrared spectroscopy in depth of anesthesia monitoring research, and expounded the unsolved problems and future prospects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2939 (2012)
In-situ FTIR Study on the Absorption and Transformation of Glyoxal on the Surface of Dust Particles
SHEN Xiao-li, CHEN Zhong-ming, ZHAO Yue, and HUANG Dao
Glyoxal is one of the most important volatile organic compounds in the atmosphere. The reactions of glyoxal in the gaseous and aqueous phases and on the surfaces of secondary inorganic acidic aerosols can lead to atmospheric secondary organic aerosol (SOA) formation. However, up to now, there is no report on the heteroGlyoxal is one of the most important volatile organic compounds in the atmosphere. The reactions of glyoxal in the gaseous and aqueous phases and on the surfaces of secondary inorganic acidic aerosols can lead to atmospheric secondary organic aerosol (SOA) formation. However, up to now, there is no report on the heterogeneous reaction of glyoxal on dust particles. The present work investigated the heterogeneous absorption and transformation mechanisms of glyoxal on SiO2 and α-Al2O3 particles. The progress of heterogeneous reaction conducted in the flow tube reactor was in situ monitored by transmission Fourier transform Infrared (T-FTIR). The reaction products were analyzed by combining T-FTIR with HPLC, IC, and HPLC-MS. It was found that oligomers form after the glyoxal is absorbed onto the particles (SiO2 and α-Al2O3); and for α-Al2O3, organic acids form on the particle surface in absence of illumination and oxidants. Moreover, it was revealed that water vapor favors the formation of oligomers, but suppresses the production of organic acids. These findings help further understand the SOA formation from the heterogeneous reaction of glyoxal on dust in the atmosphere..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2946 (2012)
The Correction of Cloud Effect on Satellite Near-Infrared Measurement
LIU Cheng, SUN You-wen, SI Fu-qi, BAI Wen-guang, and ZHANG Peng
The cloud effect correction is very significant to satellite remote sensing of atmospheric trace gases from near-infrared spectrum, even with a small amount of cloud, the remaining effects can still cause retrieval error even reaching up to 100%.Atmospheric carbon monoxide (CO) is one of the most important pollutants iThe cloud effect correction is very significant to satellite remote sensing of atmospheric trace gases from near-infrared spectrum, even with a small amount of cloud, the remaining effects can still cause retrieval error even reaching up to 100%.Atmospheric carbon monoxide (CO) is one of the most important pollutants in the troposphere. This study, takeing CO as the example, described the cloud effect and the cloud correction on retrieval result from SCIAMACHY measurement. To validate the correction method, we compared both corrected and uncorrected results with the independent ground based FTIR measurements. After the correction, the agreement between satellite observations and FTIR measurements further improves..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2950 (2012)
Application Study of the Thermal Infrared Emissivity Spectra in the Estimation of Salt Content of Saline Soil
XIA Jun, TASHPOLAT·Tiyip, MAMAT·Sawut, ZHANG Fei, and HAN Gui-hong
Studying of soil salinization is of great significance for agricultural production in arid area oasis, thermal infrared remote sensing technology provides a new technology and method in this field. Authors used Fourier transform infrared spectrometer to measure the oasis saline soil in field, employed iterative spectraStudying of soil salinization is of great significance for agricultural production in arid area oasis, thermal infrared remote sensing technology provides a new technology and method in this field. Authors used Fourier transform infrared spectrometer to measure the oasis saline soil in field, employed iterative spectrally smooth temperature/emissivity separation algorithm(ISSTES) to separate temperature and emissivity, and acquired the thermal infrared emissivity data of the saline soil. Through researching the emissivity spectral feature of saline soil, and concluded that soil emissivity will reduce with the increasing of salt content from 8 to 13 μm, so emissivity spectra is more sensitive to salt factor from 8 to 9.5 μm. Then, analyzed the correlation between original emissivity spectra and its first derivative, second derivative and normalized ratio with salt content, the result showed that they have a negative correlation relationship between soil emissivity and salt content, and the correlation between emissivity first derivative and salt content is highest, reach to 0.724 2, the corresponding bands are from 8.370 745～8.390 880 μm. Finally, established the quadratic function regression model, its determination coefficient is 0.741 4, and root mean square error is 0.235 5, the result explained that the approach of using thermal infrared emissivity to retrieve the salt content of saline soil is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2956 (2012)
Research on Variable Selection of Wheat Near-Infrared Spectroscopy Based on Latent Projective Graph
HUAN Ke-wei, ZHENG Feng, LIU Xiao-xi, CAI Xiao-long, CAI Hong-xing, WANG Rui, and SHI Xiao-guang
To simplify the model and improve the precision of prediction model, latent projective graph (LPG) was used for variable selection. The original spectrum was processed by continuous wavelet transform (CWT), LPG was obtained by principal component analysis (PCA), and based on the assumption that collinear wavelengths miTo simplify the model and improve the precision of prediction model, latent projective graph (LPG) was used for variable selection. The original spectrum was processed by continuous wavelet transform (CWT), LPG was obtained by principal component analysis (PCA), and based on the assumption that collinear wavelengths might have the same contribution to the modeling, a few latent spectral variables were selected for establishing prediction model. The root mean square error of prediction (RMSEP) model was 0.3454, better than other modeling methods. This work proved that variable selection with LPG could simplify the near-infrared spectral model effectively, and improve the precision of prediction model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2962 (2012)
Infrared Energy Level Lifetime Measurement System by Visible Upconversion Luminescence Detection Based on Double-Pulse Injection LD Module
FAN Xian-guang, LI Ai-hua, XU Ying-jie, and ZUO Yong
The lifetime of Er3+ and 4I13/2 energy level is of very significance for evaluating the application potential of Er3+-doped materials in optical communication. In the present article, based on the Er3+ excited state absorption upconversion (UC) luminescence under 980 nm double-pulse injection LD excitation, the authorsThe lifetime of Er3+ and 4I13/2 energy level is of very significance for evaluating the application potential of Er3+-doped materials in optical communication. In the present article, based on the Er3+ excited state absorption upconversion (UC) luminescence under 980 nm double-pulse injection LD excitation, the authors detected the red UC luminescence intensity under different time gap between double pulses, then according to the dependence between UC red luminescence intensity and time gap between double pulses, deduced the fitting formula for obtained medial energy level lifetime of Er3+, and actualized the measurement of infrared level lifetime in visible region. So, combining photomultiplier tube (R2658) with double-pulse injection LD module with controllable time gap and synchronous pulse sample, we can obtain all the infrared level lifetime of Er3+, and this is a cost saving lifetime measurement system with μs resolution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2966 (2012)
Study on Quality Evaluation of Dafo Longjing Tea Based on Near Infrared Spectroscopy
ZHOU Xiao-fen, YE Yang, ZHOU Zhu-ding, and QIAN Yuan-feng
Seven quantitative analysis models for Dafo Longjing tea, including tea color, liquor color, aroma, taste, infused leaf, total points of five factors and total points of six factors, were built by applying near infrared spectroscopy combined with partial least squares (NIRS-PLS), in order to find a objective and scientSeven quantitative analysis models for Dafo Longjing tea, including tea color, liquor color, aroma, taste, infused leaf, total points of five factors and total points of six factors, were built by applying near infrared spectroscopy combined with partial least squares (NIRS-PLS), in order to find a objective and scientific method for tea quality evaluation. Results showed that both the calibration samples and the prediction samples of the seven models had acquired a high fitting degree when the number of principal components was below 10, and the value of Rc, RMSEC, Rp and RMSEP were between 90.48%～98.43%, 1.14%～2.09%, 90.00%～96.65%, and 1.52%～2.84%, respectively. Among them, the total points of five factors model had the best prediction performance, and the value of Rp and RMSEP was 96.65% and 1.52%, respectively. Moreover, it was also found that the prediction precision of total points models were higher than that of single factor ones. It seems that the quality evaluation of Dafo Longjing tea could be realized by using NIRS-PLS to some extent..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2971 (2012)
A Research of Stability Method for Non-Dispersive Infrared Gas Analysis Based on Multi-Parameter Model
LI Cui-ping, HAN Jiu-qiang, DONG Xiao-qiang, DING Ya-ming, ZHANG Dian-guo, and MU Ning
To non-dispersive infrared gas analysis, it was the most difficult challenge to maintain very low zero and temperature drift over long periods. Electronic and detector response drifts irremediably required some form of manual zeroing procedure. To solve zero and temperature drift, a multi-parameters model was developedTo non-dispersive infrared gas analysis, it was the most difficult challenge to maintain very low zero and temperature drift over long periods. Electronic and detector response drifts irremediably required some form of manual zeroing procedure. To solve zero and temperature drift, a multi-parameters model was developed, by which zero and temperature drifts were automatically corrected. These parameters include zero gas intensity, reference channels intensity, standard temperature, environment temperature, temperature drift coefficients etc. Trial results and in-situ applications showed that the monitoring precisions of the instrument were lesser than 5%F.S in different temperatures and for a long time. The average precision of monitoring carbon monoxide concentration increased respectively from 9.26% to 1.23%, and monitoring hydrocarbon concentration from 10.61% to 0.70% before and after compensated. The instrument required essentially no periodic calibration and have very low maintenance cost..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2976 (2012)
The FTIR Spectral Characteristics and Comparison Study of Astragalus Menbranceus Soil
LIU Bi-wang, ZHAO Hui-hui, ZHAO Ping, WANG Wei, XUE Hui-qing, WANG Yong-hui, ZHOU Ran, and LIU Yang-qing
To study the genuine soil of Astragalus menbranceus grows, FTIR spectrometry was used, which is accurate, simple and efficient and has high resolution. The genuine soils include six areas in Hunyuan of Shanxi province, three areas in Yingxian of Shanxi province, Fansi of Shanxi province, and Guyang of Inner Mongolia. DTo study the genuine soil of Astragalus menbranceus grows, FTIR spectrometry was used, which is accurate, simple and efficient and has high resolution. The genuine soils include six areas in Hunyuan of Shanxi province, three areas in Yingxian of Shanxi province, Fansi of Shanxi province, and Guyang of Inner Mongolia. Different growth years of two to five for each area were also studied. The results show that there are significant differences between Astragalus menbranceus soil FTIR spectrometry and general soil’s, between soil of Astragalus menbranceus growth and radix codonopsitis growth, between different soil of Astragalus menbranceus growth, providing useful information for the area chose of Chinese herb cultural and transplantation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2981 (2012)
Outlier Sample Discriminating Methods for Building Calibration Model in Melons Quality Detecting Using NIR Spectra
TIAN Hai-qing, WANG Chun-guang, ZHANG Hai-jun, YU Zhi-hong, and LI Jian-kang
Outlier samples strongly influence the precision of the calibration model in soluble solids content measurement of melons using NIR Spectra. According to the possible sources of outlier samples, three methods (predicted concentration residual test; Chauvenet test; leverage and studentized residual test) were used to diOutlier samples strongly influence the precision of the calibration model in soluble solids content measurement of melons using NIR Spectra. According to the possible sources of outlier samples, three methods (predicted concentration residual test; Chauvenet test; leverage and studentized residual test) were used to discriminate these outliers respectively. Nine suspicious outliers were detected from calibration set which including 85 fruit samples. Considering the 9 suspicious outlier samples maybe contain some no-outlier samples, they were reclaimed to the model one by one to see whether they influence the model and prediction precision or not. In this way, 5 samples which were helpful to the model joined in calibration set again, and a new model was developed with the correlation coefficient (r) 0.889 and root mean square errors for calibration (RMSEC) 0.601°Brix. For 35 unknown samples, the root mean square errors prediction (RMSEP) was 0.854°Brix. The performance of this model was more better than that developed with non outlier was eliminated from calibration set（r=0.797, RMSEC=0.849°Brix, RMSEP=1.19°Brix）, and more representative and stable with all 9 samples were eliminated from calibration set（r=0.892, RMSEC=0.605°Brix, RMSEP=0.862°Brix）..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2987 (2012)
Noninvasive Measurement of Human Serum Protein Concentration by Near-Infrared Reflection Spectra for Tongue Inspection
LI Jia-xing, LIN Ling, LI Zhe, LI Gang, and SONG Wei
In the present paper, a kind of noninvasive determination for human serum protein concentration of albumin, globulin and total protein was explored based on the technology of near-infrared reflectance spectra. Reflectance spectra on the tongue tip of 58 volunteers were collected. Because these is an nonlinear mapping rIn the present paper, a kind of noninvasive determination for human serum protein concentration of albumin, globulin and total protein was explored based on the technology of near-infrared reflectance spectra. Reflectance spectra on the tongue tip of 58 volunteers were collected. Because these is an nonlinear mapping relationship induced by the individual differences between these spectra data and serum protein concentration, SVM was used to establish quantitative regression models of 3 kinds of protein concentration respectively after the normalized spectral reflectance was calculated and the protein content statistics distribution of the sample set was analyzed. In addition, results of SVM were compared with that of PLS. The results show that the predictive effect for calibrated model of SVM is obviously better than that of PLS. Using SVM model to predict the prediction set, the correlation coefficients of ALB, GLB and TP are respectively 0.894, 0.931 and 0.863, and root mean square errors are 2.19, 1.93 and 4.38. So SVM can resist the impact of nonlinear factors among in-vivo determinations, and enhance the robustness of the models. Meanwhile it was also showed that the near infrared spectral information for tongue can relatively objectively reflect changes in human physiological and biochemical indexes, and this technology for noninvasive determination of serum protein concentration is highly feasible.<作者简国家自然科学基金项目（30973964）, 天津市应用基础及前沿技术研究计划项目（11JCZDJC17100）, 天津市科技计划项目: 科技型中小企业创新基金项目（10ZXCXSY10400）资助介>李家星, 女, 1979年生, 天津大学精密仪器与光电子工程学院在读博士.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2992 (2012)
Combination of Near Infrared Spectroscopy and Electronic Nose for Alcohol Quantification during the Red Wine Fermentation
ZHANG Shu-ming, YANG Yang, and NI Yuan-ying
The red wine fermentation needs fast and nondestructive techniques, which can help to control the fermentation process and assure the quality of wine. In the present study, near infrared spectroscopy (NIR) and electronic nose (EN) were used to predict the alcohol content during the red wine alcoholic fermentation. CaliThe red wine fermentation needs fast and nondestructive techniques, which can help to control the fermentation process and assure the quality of wine. In the present study, near infrared spectroscopy (NIR) and electronic nose (EN) were used to predict the alcohol content during the red wine alcoholic fermentation. Calibration models were developed between instrumental data and chemical analysis using principal component regression (PCR) and partial least squares regression (PLSR) with cross validation. Good correlations (R>0.99) were acquired for both the models developed by the NIR and EN data. However, RMSEC and RMSEP were a little larger. Combining NIR and EN can optimize the model and improve the prediction accuracy. The PLSR model based on combined data shows the best correlation (R=0.999 2), with RMSEC and RMSEP being 0.206 and 0.205% (v/v), respectively. Both NIR spectroscopy and EN can predict the alcohol concentration during the alcoholic fermentation of red wine, and the combination of two instruments can improve the analysis precision. Although the measurements were carried out in off-line mode, this study demonstrates that NIR and EN can be used as on line, fast, nondestructive and in time techniques to provide in-time information about the fermentation process and to assure the quality of final products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 2997 (2012)
Near-Infrared Spectrum Detection Result Influenced by Navel Oranges Placement Position
XU Wen-li, SUN Tong, WU Wen-qiang, and LIU Mu-hua
The present paper studies the near-infrared spectroscopy of soluble solids content in navel orange that was influenced by different placement positions of the navel orange. According to the different angles between incident light and the straight line composed by navel orange stems and pit, the authors chose three diffThe present paper studies the near-infrared spectroscopy of soluble solids content in navel orange that was influenced by different placement positions of the navel orange. According to the different angles between incident light and the straight line composed by navel orange stems and pit, the authors chose three different placement positions, vertical (90°), parallel (0°) and random(not including 0°and 90°). The authors acquired the semi-transmission spectrum of the navel orange placed in different positions in the wavelength range of 465～1 150 nm by the miniature fiber spectrometer USB4000, there were 336 navel orange samples in the experiment, 228 samples weree used as calibration set, and the rest 108 samples were used as prediction set. The authors used partial least-square regression combined with different pre-processing methods to establish the prediction model of SSC in navel orange with different placement positions. The result shows that when the angle is vertical the prediction models of SSC in navel orange are good, and the best correlation coefficient of the model is rc=0.93, RMSEC=0.37%, rp=0.88, and RMSEP=0.49%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3002 (2012)
Identification of Different Citrus sinensis(L.) Osbeck Trees Varieties Using Fourier Transform Infrared Spectroscopy and Hierarchical Cluster Analysis
YI Shi-lai, DENG Lie, HE Shao-lan, SHI You-ming, ZHENG Yong-qiang, L Qiang, XIE Rang-jin, WEI Xian-guo, LI Song-wei, and JIAN Shui-xian
Researched on diversity of the spring leaf samples of seven different Citrus sinensis(L.) Osbeck varieties by Fourier transform infrared (FTIR) spectroscopy technology, the results showed that the Fourier transform infrared spectra of seven varieties leaves was composited by the absorption band of cellulose and polysacResearched on diversity of the spring leaf samples of seven different Citrus sinensis(L.) Osbeck varieties by Fourier transform infrared (FTIR) spectroscopy technology, the results showed that the Fourier transform infrared spectra of seven varieties leaves was composited by the absorption band of cellulose and polysaccharide mainly, the wave number of characteristics absorption peaks were similar at their FTIR spectra. However, there were some differences in shape of peaks and relatively absorption intensity. The conspicuous difference was presented at the region between 1 500 and 700 cm-1 by second derivative spectra. Through the hierarchical cluster analysis(HCA) of second derivative spectra between 1 500 and 700 cm-1, the results showed that the clustering of the different varieties of Citrus sinensis(L.) Osbeck varieties was classification according to genetic relationship. The results showed that FTIR spectroscopy combined with hierarchical cluster analysis could be used to identify and classify of citrus varieties rapidly, it was an extension method to study on early leaves of varieties orange seedlings..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3006 (2012)
Improving Precision in Coal Moisture Detection Using Wavelet Transform
JIA Hao, FU Qiang, HAN Chan-juan, ZOU De-bao, CHEN Wen-liang, and XU Ke-xin
Moisture, as a core determination of the economic value of coal, can result in the utilization and energy inefficiency. Near-infrared (NIR) spectroscopy, with advantages of high accuracy and low cost, provides significant solution to the quick and non-invasive detection of coal moisture. In the present paper, the improMoisture, as a core determination of the economic value of coal, can result in the utilization and energy inefficiency. Near-infrared (NIR) spectroscopy, with advantages of high accuracy and low cost, provides significant solution to the quick and non-invasive detection of coal moisture. In the present paper, the improvement of the coal moisture analysis was conducted based on the precision of 1% and insufficient comparisons in recent experiments, and aspects of spectrum pretreatment and wavelength selection were mainly discussed. The optimized result with R-square of 0.995, RMSEC of 0.06% and RMSEP of 0.27% indicates the priority of wavelet decomposition and reconstruction, compared with other methods, in the noise reduction and baseline removing of original spectra (1 300～2 400 nm) before PLS modeling, and the stability experiment validates its robust potential in improving precision of coal moisture detection based on the NIR spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3010 (2012)
Tobacco Quality Analysis of Industrial Classification of Different Years Using Near-Infrared (NIR) Spectrum
WANG Yi, MA Xiang, WEN Ya-dong, YU Chun-xia, WANG Luo-ping, ZHAO Long-lian, and LI Jun-hui
In this study, tobacco quality analysis of main Industrial classification of different years was carried out applying spectrum projection and correlation methods. The group of data was near-infrared (NIR) spectrum from Hongta Tobacco（Group）Co., Ltd. 5730 tobacco leaf Industrial classification samples from Yuxi in YunnaIn this study, tobacco quality analysis of main Industrial classification of different years was carried out applying spectrum projection and correlation methods. The group of data was near-infrared (NIR) spectrum from Hongta Tobacco（Group）Co., Ltd. 5730 tobacco leaf Industrial classification samples from Yuxi in Yunnan province from 2007 to 2010 year were collected using near infrared spectroscopy, which from different parts and colors and all belong to tobacco varieties of HONGDA. The conclusion showed that, when the samples were divided to two part by the ratio of 2∶1 randomly as analysis and verification sets in the same year, the verification set corresponded with the analysis set applying spectrum projection because their correlation coefficients were above 0.98. The correlation coefficients between two different years applying spectrum projection were above 0.97. The highest correlation coefficient was the one between 2008 and 2009 year and the lowest correlation coefficient was the one between 2007 and 2010 year. At the same time, The study discussed a method to get the quantitative similarity values of different industrial classification samples. The similarity and consistency values were instructive in combination and replacement of tobacco leaf blending..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3014 (2012)
Based on the LS-SVM Modeling Method Determination of Soil Available N and Available K by Using Near-Infrared Spectroscopy
LIU Xue-mei, and LIU Jian-she
Visible infrared spectroscopy (Vis/SW-NIRS) was investigated in the present study for measurement accuracy of soil properties,namely, available nitrogen(N) and available potassium(K). Three types of pretreatments including standard normal variate (SNV), multiplicative scattering correction (MSC) and Savitzky-Golay smooVisible infrared spectroscopy (Vis/SW-NIRS) was investigated in the present study for measurement accuracy of soil properties,namely, available nitrogen(N) and available potassium(K). Three types of pretreatments including standard normal variate (SNV), multiplicative scattering correction (MSC) and Savitzky-Golay smoothing+first derivative were adopted to eliminate the system noises and external disturbances. Then partial least squares (PLS) and least squares-support vector machine (LS-SVM) models analysis were implemented for calibration models. Simultaneously, the performance of least squares-support vector machine (LS-SVM) models was compared with three kinds of inputs, including PCA(PCs), latent variables(LVs), and effective wavelengths (EWs). The results indicated that all LS-SVM models outperformed PLS models. The performance of the model was evaluated by the correlation coefficient (r2) and RMSEP. The optimal EWs-LS-SVM models were achieved, and the correlation coefficient (r2) and RMSEP were 0.82 and 17.2 for N and 0.72 and 15.0 for K, respectively. The results indicated that visible and short wave-near infrared spectroscopy (Vis/SW-NIRS)(325～1 075 nm) combined with LS-SVM could be utilized as a precision method for the determination of soil properties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3019 (2012)
Obtaining Aerosol Backscattering Coefficient Using Pure Rotational Raman-Mie Scattering Spectrum
RONG Wei, CHEN Si-ying, ZHANG Yin-chao, CHEN He, and GUO Pan
Both the traditional Klett and Fernald methods used to obtain atmospheric aerosol backscattering coefficient require the hypothesis of relationship between the extinction coefficient and backscattering coefficient, and this will bring error. According to the theory that the pure rotational Raman backscattering coefficiBoth the traditional Klett and Fernald methods used to obtain atmospheric aerosol backscattering coefficient require the hypothesis of relationship between the extinction coefficient and backscattering coefficient, and this will bring error. According to the theory that the pure rotational Raman backscattering coefficient is only related to atmospheric temperature and pressure, a new method is presented for inverting aerosol backscattering coefficient, which needed the intensity of elastic scattering and rotational Raman combined with atmospheric temperature and pressure obtained with the sounding balloons in this article. This method can not only eliminate the errors of the traditional Klett and Fernald methods caused by the hypothesis, but also avoid the error caused by the correction of the overlap. Finally, the aerosol backscattering coefficient was acquired by using this method and the data obtained via the Raman-Mie scattering Lidar of our lab. And the result was compared with that of Klett and Fernald..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3024 (2012)
Characterization of Pure and Doped Amorphous WO3 Films by Raman Spectroscopy
L Gang, WU Yong-gang, WU He-yun, XIA Zi-huan, and LIU Ren-chen
Pure, TiO2-doped and TiO2/Ag-doped WO3 films were prepared by evaporation and electron beam evaporating. Raman spectroscopy and chronoamperometry were used to characterize the electrochromic properties of the samples. The correlation between the relative intensity of the Raman peaks, corresponding to the Raman sharp pePure, TiO2-doped and TiO2/Ag-doped WO3 films were prepared by evaporation and electron beam evaporating. Raman spectroscopy and chronoamperometry were used to characterize the electrochromic properties of the samples. The correlation between the relative intensity of the Raman peaks, corresponding to the Raman sharp peak of the crystalline phase at 810 cm-1 is negative, that is to say the higher the relative intensity of the Raman peaks, the smaller the coloration efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3028 (2012)
Effect of Hydrogen Bond on Line Width of Raman Spectra in Three Aqueous Solutions
WU Nan-nan, ZHANG Xue-feng, OUYANG Shun-li, and HAN Xiang-gang
In the present paper, the frequency shift and line widths of acetonitrile/H2O, DMSO/H2O and acetone/H2O aqueous binary solutions at different concentration were measured by Raman spectroscopy. The experimental results were analyzed by mixture model and empirical formula of line widths. The results show that the strongeIn the present paper, the frequency shift and line widths of acetonitrile/H2O, DMSO/H2O and acetone/H2O aqueous binary solutions at different concentration were measured by Raman spectroscopy. The experimental results were analyzed by mixture model and empirical formula of line widths. The results show that the stronger the hydrogen bond interaction, the greater the line widths of Raman spectra in the three aqueous binary solutions; the line width of Raman spectra not only is affected by concentration fluctuation, but also is affected by hydrogen bond. In addition, the experimental data points are again nicely fitted using the empirical formula..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3031 (2012)
High-Resolution THz Spectra of Six Biological and Pharmaceutical Materials
YANG Yu-ping, DONG Rui-lin, and ZHANG Zhen-wei
The temperature dependent vibrational spectra of three biological and pharmaceutical sets, genistein and biochanin A, clenbuterol hydrochloride and salbutamol, as well as ginseng R2 and R3, in the range of 0.2～4.5 THz (6.6～150.0 cm-1) are presented over the temperature range from 295 to 77 K. Although there are only soThe temperature dependent vibrational spectra of three biological and pharmaceutical sets, genistein and biochanin A, clenbuterol hydrochloride and salbutamol, as well as ginseng R2 and R3, in the range of 0.2～4.5 THz (6.6～150.0 cm-1) are presented over the temperature range from 295 to 77 K. Although there are only some minor difference in their molecular structures, the spectra of two samples in every group are quite differences in both absorption band positions and their relative intensities, and display strong linewidth narrowing and frequency blue-shift with cooling. Au 77 K, 13 highly resolved spectral features for biochanin A were obtained and the sensitivity of the experiment allows detection of amounts as small as 1.9×10-5 mol of ginseng R3. Such high-resolution THz fingerprint spectra provide a rapid, nondestructive and reliable method for the identification of these pharmaceutical settings molecules..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3035 (2012)
Double Cladding Ytterbium Doped Superfluorescence Fiber Source with 3 dB Bandwidth Reaching up to 80 nm
HAN Xu, FENG Guo-ying, HAN Jing-hua, WU Chuan-long, and ZHOU Shou-huan
The present paper reports a double pass forward superfluorescent fiber source （SFS）, which uses a length of large mode area double cladding ytterbium doped fiber as gain medium. The maximum output power of this SFS is 341 mW. With the output power between 201 and 341 mW, the 3dB bandwidth of this SFS was more than 80 nThe present paper reports a double pass forward superfluorescent fiber source （SFS）, which uses a length of large mode area double cladding ytterbium doped fiber as gain medium. The maximum output power of this SFS is 341 mW. With the output power between 201 and 341 mW, the 3dB bandwidth of this SFS was more than 80 nm. This is the widest 3 dB bandwidth obtained from ytterbium doped SFS. The output power of the SFS linearly increased with the increment of the pump source injected current. It’s output power is not very high, but under normal circumstances, it could meet the needs of the SFS. From the energy level structure of ytterbium ions and the absorption cross-section/emission cross section of ytterbium ions in quartz substrate, the physical mechanisms responsible for superfluorescence were analyzed. This double-cladding ytterbium-doped superfluorescent fiber laser benefits from the superfluorescence radiation near 1 025 and 1 075 nm, so the superfluorescence with 3 dB bandwidth reaching up to 80 nm could be obtained..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3040 (2012)
Effect of Spectra Correction on the Fluorescence Characteristics of Dissolved Organic Matter
WU Hua-yong, ZHOU Ze-yu, WANG Hong-tao, LU Wen-jing, and SUN Xiao-jie
The Excitation-emission matrix (EEM) fluorescence spectra of dissolved organic matter (DOM) are not only dependent on the chemical structure of DOM as well as the local chemical environment around the DOM, but also dependent on the instrument employed for the analysis. Thus, in order to get the real spectra of the DOM,The Excitation-emission matrix (EEM) fluorescence spectra of dissolved organic matter (DOM) are not only dependent on the chemical structure of DOM as well as the local chemical environment around the DOM, but also dependent on the instrument employed for the analysis. Thus, in order to get the real spectra of the DOM, spectra correction of the effect of the instrument-specific response is necessary. However, some studies corrected DOM spectra, while still some studies didn’t, leading to inconformity when comparing the data and the results from different groups. The present work evaluated the effect of spectra correction on the fluorescence characteristics of DOM. The results demonstrated that DOM spectra differed significantly after correction. Fluorescence intensities showed a decrease in the range of Ex/Em=220~450/250~500 nm, while an increase at Em<250 nm after correction. Fluorescence intensity ratio (FI) and humification index (HIX) derived from peak picking method showed a decrease after correction, while biological index (BIX) increased slightly. PⅠ,n, PⅡ,n and PⅢ,n derived from FRI analysis exhibited a significant increase, while PⅣ,n and PⅤ,n decreased. The results suggest that spectral correction should be included when analyzing the properties and trends of the DOM using EEM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3044 (2012)
Influence of Synthetic Technology on the Structure and Luminescent Properties of Sr3B2O6∶Eu2+ Yellow Phosphor
LIU Quan-sheng, ZHANG Xi-yan, CUI Tian, and WEI Chen-chen
The Sr3B2O6∶Eu2+ yellow phosphor for warm white LED was synthesized by high temperature solid phase method. The influences on the phosphor structure and luminous properties of sintering temperature and holding time were systematically studied. Results indicated that the optimum synthetic temperature and soaking is 1 15The Sr3B2O6∶Eu2+ yellow phosphor for warm white LED was synthesized by high temperature solid phase method. The influences on the phosphor structure and luminous properties of sintering temperature and holding time were systematically studied. Results indicated that the optimum synthetic temperature and soaking is 1 150 ℃ and 2 hours respectively. The crystalline structure of phosphor is rhombohedral Sr3B2O6. Sintering temperature and holding time has a significant influence on grain development. The excitation spectrum of phosphor composes of a wide-band spectrum main peaking at 398 nm, and the phosphor can be excited by near ultraviolet and blue light. The luminescence spectrum of phosphor is a broad spectrum peaking at 574 nm. Sintering temperature and holding time have a main effect on luminous intensity of phosphor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3049 (2012)
Three-Dimensional Fluorescence Properties of Sodium Butyl Naphthalene Sulfonate in Aqueous Solution
DAI Jing-jing, WU Jing, XIE Chao-bo, and YIN Dan-dan
Three-dimensional fluorescence spectroscopy is a new and effective chemical analysis method and is employed in water environment more and more widely. But the utilization is limited by the bottleneck, i.e. shortage of fluorescence data of contaminants in aqueous solution. This paper presents the three-dimensional fluorThree-dimensional fluorescence spectroscopy is a new and effective chemical analysis method and is employed in water environment more and more widely. But the utilization is limited by the bottleneck, i.e. shortage of fluorescence data of contaminants in aqueous solution. This paper presents the three-dimensional fluorescence properties of a toxic contaminant, sodium butyl naphthalene sulfonate, in aqueous solution. There existed four peaks at about λex/em=230/340, 280/340, 225/650 and 280/650 nm respectively. The intensity of all the peaks except the peak at 225/650 nm increased as the concentration augmented, while the intensity of peak at 225/650 nm increased as the concentration augmented when the concentration was less than 0.5 mg·L-1, and decreased as the concentration augmented when the concentration was greater than 0.5 mg·L-1. The pH would lead to the variation in the fluorescence intensity vary rather than to change the peak location. The fluorescence intensities were stable when pH was in the range of 2～10. The study indicates that it is feasible to measure sodium butyl naphthalene sulfonate directly with the fluorescence intensity at 280/340 nm. The linear range is between 0 and 0.033 3 mg·L-1. This simple and rapid method could provide reliable results without complex pretreatment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3053 (2012)
Study on Determination of Carbaryl Content in Duck Meat Based on Synchronous Fluorescence Spectroscopy
XIAO Hai-bin, LIU Mu-hua, YUAN Hai-chao, XU Jiang, and ZHAO Jin-hui
For the rapid detection of carbaryl residue in duck meat, synchronous fluorescence spectroscopy was used, and GA combined with SVR was used to establish regression forecasting mode for the application of forecasting carbaryl residue in duck meat . Firstly, fluorescence spectrophotometer was used to get the 3D synchronoFor the rapid detection of carbaryl residue in duck meat, synchronous fluorescence spectroscopy was used, and GA combined with SVR was used to establish regression forecasting mode for the application of forecasting carbaryl residue in duck meat . Firstly, fluorescence spectrophotometer was used to get the 3D synchronous fluorescence spectra of carbaryl hydrolysate and duck solution containing carbaryl, and 140 nm was selected as the optimum wavelength difference Δλ; Secondly, some concentration quenching was analysed. Finally, GA was used to optimize and choose the 3D synchronous fluorescence spectra. According to the root mean square error of cross-validation (RMSECV) 21 characteristic wavelengths were chosen, then the full wavelength and 21 characteristic wavelengths were used as input characteristic variables of SVR regression forecasting model respectively. At last the results showed that characteristic wavelengths chosen by GA can get better forecasting results, and the correlation coefficient of the prediction samples set and the root mean squared error (RMSEP) were 0.976 4 and 12.232 2, respectively. The results of experiments showed that the synchronous fluorescence spectroscopy could be used to detect carbaryl residue in duck meat efficiently and rapidly when combined with GA-SVR..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3058 (2012)
Studies on Laser Induced Dispersive Fluorescence Spectroscopy of SO2 Molecule Excited by Two-Photon
ZHAO Zhan-long, LI Ming, ZHANG Lian-shui, CHEN Si-yuan, and ZHAO Kui-fang
The processes of excitation and complicated de-excitation of A-symmetric state in the first-excited band of SO2 molecule were studied experimentally with the techniques of two-photon laser induced dispersive fluorescence spectroscopy where a pulsed dye laser (579 nm) was used as excitation sources. The SO2 molecule whiThe processes of excitation and complicated de-excitation of A-symmetric state in the first-excited band of SO2 molecule were studied experimentally with the techniques of two-photon laser induced dispersive fluorescence spectroscopy where a pulsed dye laser (579 nm) was used as excitation sources. The SO2 molecule which were excited from ground state X1A1 to the high vibrational levels of A1A2 state by absorbing two photons, will realize the repopulation in several vibration-rotational energy levels of A1A2, B1B1 and a3B1 states by internal energy conversion and collision relaxation. Because of transitions to the different vibrational levels of ground electronic state X1A1 from the ground vibrational levels of A1A2, B1B1 and a3B1, the fluorescence spectrum envelopes centered at 305 and 425 nm and the regular fluorescence lines centered at 347.2 nm were formed in the fluorescence spectra. In addition, the process of tri-photon excitation X1A1→C1B2 of SO2 molecule was observed, and the result of the process was the fluorescence spectrum envelope in 200~278 nm and the overlapping fluorescence lines centered at 425 nm. The harmonic frequencies of the symmetry stretch vibration and the bendvibration and the anharmonic constants of stretch vibration mode and the bend vibration mode of related states were calculated from the experimental data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3063 (2012)
Combined Application of Multiple Fluorescence in Research on the Degradation of Fluoranthene by Potassium Ferrate
LI Si, YU Dan-ni, JI Fang-ying, ZHOU Guang-ming, and HE Qiang
The degradation of fluoranthene was researched by combined means of multiple fluorescence spectra, including emission, synchronous, excitation emission matrix (EEM), time-scan and photometry. The characteristics of the degradation and fluoranthene molecular changes within the degradation’s process were also discussed aThe degradation of fluoranthene was researched by combined means of multiple fluorescence spectra, including emission, synchronous, excitation emission matrix (EEM), time-scan and photometry. The characteristics of the degradation and fluoranthene molecular changes within the degradation’s process were also discussed according to the information about the degradation provided by all of the fluorescence spectra mentioned above. The equations of fluoranthene’s degradation by potassium ferrate were obtained on the bases of fitting time-scan fluorescence curves at different time, and the degradation’s kinetic was speculated accordingly. From the experimental results, multiple fluorescence data commonly reflected that it had same degradation rate at the same reaction time. t=10 s, and the degradation rate is ～55%, t=25 s, ～81%, t=40 s, ～91%. No new fluorescent characteristic was observed within every degradation’ stage. The reaction stage during t≤20 s was crucial, in which the degradation process is closest to linear relationship. After this beginning stage, the linear relationship deviated gradually with the development of the degradation process. The degradation of fluoranthene by potassium ferrate was nearly in accord with the order of the first order reaction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3068 (2012)
Quantitative Grain Fluorescence Responds to Residual Oil Zones and Paleo-Oil Zones
LI Zhuo, JIANG Zhen-xue, and LI Feng
In order to investigate quantitative grain fluorescence responding to residual oil zones and palaeo-oil zones, samples from sandstone reservoirs in well TZ421 in Tazhong area, Tarim Basin, NW China, were used to carry out quantitative grain fluorescence (QGF and QGF-E) measurement and analysis. A palaeo-oil zone can beIn order to investigate quantitative grain fluorescence responding to residual oil zones and palaeo-oil zones, samples from sandstone reservoirs in well TZ421 in Tazhong area, Tarim Basin, NW China, were used to carry out quantitative grain fluorescence (QGF and QGF-E) measurement and analysis. A palaeo-oil zone can be delineated in well TZ421 between 3 720 and 3 620 m with strong QGF responds. A residual oil zone was discovered in well TZ421 between 3 680 and 3 620 m with strong QGF-E responds. The presence of a residual oil zone and a palaeo-oil zone in well TZ421 below the current oil-water contact indicates that some oils were lost after the initial charge. The reservoir is believed to have been charged initially down to 3 720 m at the depth of the palaeo-oil-water contact. The presence of a 60 m residual oil zone below the current oil-water contact, as delineated by QGF-E, suggests that the palaeo-oil zones leaked in two epochs and part of the oil lost quite recently. The strong QGF responds in the current condensate gas interval indicates that the initially charged oil was partly displaced by gas and formed an oil zone with a gas cap..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3073 (2012)
Effect of Annealing Temperature on the Crystallization and Spectroscopic Response of a Small-Molecule Semiconductor Doped in Polymer Film
YIN Ming, ZHANG Xin-ping, and LIU Hong-mei
The crystallization properties of the perylene (EPPTC) molecules doped in the solid film of the derivative of polyfluorene (F8BT) at different annealing temperatures, as well as the consequently induced spectroscopic response of the exciplex emission in the heterojunction structures, were studied in the present paper. The crystallization properties of the perylene (EPPTC) molecules doped in the solid film of the derivative of polyfluorene (F8BT) at different annealing temperatures, as well as the consequently induced spectroscopic response of the exciplex emission in the heterojunction structures, were studied in the present paper. Experimental results showed that the phase separation between the small and the polymer molecules in the blend film is enhanced with increasing the annealing temperature, which leads to the crystallization of the EPPTC molecules due to the strong π—π stacking. The size of the crystal phase increases with increasing the annealing temperature. However, this process weakens the mechanisms of the heterojunction configuration, thus, the total interfacial area between the small and the polymer molecules and the amount of exciplex are reduced significantly in the blend film. Meanwhile, the energy transfer from the polymer to the small molecules is also reduced. As a result, the emission from the exciplex becomes weaker with increasing the annealing temperature, whereas the stronger emission from the polymer molecules and from the crystal phase of the small molecules can be observed. These experimental results are very important for understanding and tailoring the organic heterojunction structures. Furthermore, this provides photophysics for improving the performance of photovoltaic or solar cell devices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3078 (2012)
The Arctic Sea Ice Refractive Index Retrieval Based on Satellite AMSR-E Observations
CHEN Han-yue, BI Hai-bo, and NIU Zheng
The refractive index of sea ice in the polar region is an important geophysical parameter. It is needed as a vital input for some numerical climate models and is helpful to classifying sea ice types. In the present study, according to Hong Approximation (HA), we retrieved the arctic sea ice refractive index at 6.9, 10.The refractive index of sea ice in the polar region is an important geophysical parameter. It is needed as a vital input for some numerical climate models and is helpful to classifying sea ice types. In the present study, according to Hong Approximation (HA), we retrieved the arctic sea ice refractive index at 6.9, 10.7, 23, 37, and 89 GHz in different arctic climatological conditions. The refractive indices of wintertime first year (FY) sea ice and summertime ice were derived with average values of 1.78～1.75 and 1.724～1.70 at different frequencies respectively, which are consistent with previous studies. However, for multiyear (MY) ice, the results indicated relatively large bias between modeled results since 10.7 GHz. At a higher frequency, there is larger MY ice refractive index difference. This bias is mainly attributed to the volume scattering effect on MY microwave radiation due to emergence of massive small empty cavities after the brine water in MY ice is discharged into sea. In addition, the retrieved sea ice refractive indices can be utilized to classify ice types (for example, the winter derivation at 89 GHz), to identify coastal polynyas (winter retrieval at 6.9 GHz), and to outline the areal extent of significantly melting marginal sea ice zone (MIZ) (summer result at 6.9 GHz). The investigation of this study suggests an effective tool of passive microwave remote sensing in monitoring sea ice refractive index variability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3083 (2012)
Synthesis of Particle-Free Silver Conductive Ink and Investigation of Fabrication of Conductive Film by Printing
NIE Xiao-lei, WANG Hong, and ZOU Jing
Particle-free conductive ink was prepared, taking silver citrate as conductive metal precursor, sec-butylamine as complexing agent and ethanol as media adjusting the viscosity and wettability. The ink could be printed on PET substrate by gravure printing, and silver conductive film with high electrical conductivity wasParticle-free conductive ink was prepared, taking silver citrate as conductive metal precursor, sec-butylamine as complexing agent and ethanol as media adjusting the viscosity and wettability. The ink could be printed on PET substrate by gravure printing, and silver conductive film with high electrical conductivity was obtained after thermal treated at low temperature. Silver citrate, silver citrate based conductive ink and silver conductive film were characterized with EDS, STA, IR, XRD, SEM and four point probe method. The results of STA showed that the mass of the conductive ink came to constant at 132 ℃ which is much lower than that of silver citrate (210 ℃); the results of SEM and XRD showed that the silver conductive film cured at 150 ℃ was constituted by compact silver nano particles with high purity; the result of four point probe method showed that its sheet resistance was 1.83 Ω·□-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3089 (2012)
Nondestructive Measurement of Sugar Content of Hami Melon Based on Diffuse Reflectance Hyperspectral Imaging Technique
MA Ben-xue, XIAO Wen-dong, QI Xiang-xiang, HE Qing-hai, and LI Feng-xia
The research on nondestructive test for detecting the sugar content of Hami melon by the technology of hyperspectral imaging was put forward. The research used the hyperspectral imaging system to get the diffuse reflective spectrum information (400～1 000 nm) of anilox class Hami melon sugar content, chose effective whoThe research on nondestructive test for detecting the sugar content of Hami melon by the technology of hyperspectral imaging was put forward. The research used the hyperspectral imaging system to get the diffuse reflective spectrum information (400～1 000 nm) of anilox class Hami melon sugar content, chose effective whole wavelength（500～820 nm）to do the modeling regression analysis the sugar content of Hami melon. The research compared the correction method of MSC and SNV, and also compared the influence of accuracy of modeling in terms of the spectrum pretreatment methods of original spectrum, first order differential, second order differential; Using the methods of PLS, SMLR and PCR, the comparative analysis of sugar content detection model effect with skin Hami melon and peel Hami melon was conducted. The results showed that after the original spectrum being processed by MSC and first order differential spectrum, modeling effect could be very good using the method of PLS and SMLR. Synthesizing correction set correlation coefficient and forecast modeling effect, it’s feasible to detect the sugar content of skin Hami melon by the PLS method, with a correction sample correlation coefficient (Rc) of 0.861 and the lower root mean square errors of correction (RMSEC) of 0.627, and a prediction sample correlation coefficient (Rp) of 0.706 and root mean square errors of prediction (RMSEP) of 0.873. The best effect to detecti the sugar content of peel Hami melon was obtained by the SMLR method with a correction sample correlation coefficient (Rc) of 0.928 and the lower root mean square errors of correction (RMSEC) of 0.458, with a Prediction sample correlation coefficient (Rp) of 0.818 and root mean square errors of prediction (RMSEP) of 0.727. The results of this study indicate that the technology of hyperspectral imaging can be used to predict the sugar content of Hami melon..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3093 (2012)
D-Value Estimation of Dynamic Spectrum Based on the Statistical Methods
LIN Ling, LI Yong-cheng, WANG Meng-jun, ZHOU Mei, LI Gang, and ZHANG Bao-ju
To realize the noninvasive concentration detection of blood components and improve the drawbacks existing in the time-domain single-trial estimation method of “dynamic spectrum” (DS), the D-value estimation method based on the statistical properties was proposed. We extracted the absolute difference between two correspTo realize the noninvasive concentration detection of blood components and improve the drawbacks existing in the time-domain single-trial estimation method of “dynamic spectrum” (DS), the D-value estimation method based on the statistical properties was proposed. We extracted the absolute difference between two corresponding values of each wavelength to make up the DS, selected the valid DSs from the DSs of different times by statistic method, and the valid DSs were superimposed and averaged as the final output of the DS. Data collected from 48 volunteers were processed by the D-value estimation and the single-trial estimation, respectively; and then the comparison was carried out between the two methods. Compared with the single-trial estimation, the valid DSs extracted by the D-value estimation were slightly better in denoising; And the average number of the remained valid DSs is improved from 48 to 130; the average of mean square error among the valid DSs is improved from 0.39 to 0.006; the speed of data processing is increased by nearly 20 times. The new method can significantly improve the quality of the extraction of DS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3098 (2012)
Hyperspectral Estimation of Leaf Water Content for Winter Wheat Based on Grey Relational Analysis(GRA)
JIN Xiu-liang, XU Xin-gang, WANG Ji-hua, LI Xin-chuan, WANG Yan, TAN Chang-wei, ZHU Xin-kai, and GUO Wen-shan
The objective of the present study was to compare two methods for the precision of estimating leaf water content (LWC) in winter wheat by combining stepwise regression method and partial least squares (SRM-PLS) or PLS based on the relational degree of grey relational analysis (GRA) between water vegetation indexes (WVIThe objective of the present study was to compare two methods for the precision of estimating leaf water content (LWC) in winter wheat by combining stepwise regression method and partial least squares (SRM-PLS) or PLS based on the relational degree of grey relational analysis (GRA) between water vegetation indexes (WVIs) and LWC. Firstly, data utilized to analyze the grey relationships between LWC and the selected typical WVIs were used to determine the sensitivity of different WVIs to LWC. Secondly, the two methods of estimating LWC in winter wheat were compared, one was to directly use PLS and the other was to combine SRM and PLS, and then the method with the highest determination coefficient (R2) and lowest root mean square error (RMSE) was selected to estimate LWC in winter wheat. The results showed that the relationships between the first five WVI and LWC were stable by using GRA, and then LWC was estimated by using PLS and SRM-PLS at the whole stages with the R2 and RMSEs being 0.605 and 0.575, 4.75% and 7.35%, respectively. The results indicated that the estimation accuracy of LWC could be improved by using GRA firstly and then by using PLS and SRM-PLS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3103 (2012)
Use of Open-Path TDL Technique and the Backward Lagrangian Stochastic Model to Monitor Ammonia Emission from Summer Maize Field
YANG Wen-liang, ZHU An-ning, ZHANG Jia-bao, ZHANG Yu-jun, HE Ying, WANG Li-ming, CHEN Xiao-min, and CHEN Wen-chao
The backward Lagrangian stochastic dispersion model in conjunction with open-path tunable diode absorption spectroscopy was used to quantify ammonia emissions from farmland based on the high-temporal resolution data, aiming to provide innovative achievements to diagnose patterns of ammonia flux. The results indicate thThe backward Lagrangian stochastic dispersion model in conjunction with open-path tunable diode absorption spectroscopy was used to quantify ammonia emissions from farmland based on the high-temporal resolution data, aiming to provide innovative achievements to diagnose patterns of ammonia flux. The results indicate that the bLS dispersion technique using open-path lasers to measure atmospheric ammonia concentrations is suitable for determining ammonia emissions from farmland continuously, especially for characterizing diurnal characteristics of NH3 emissions. The ammonia emissions have a significant diurnal pattern with two emission peaks from urea applied to maize on a calcareous sandy loam fluvo-aquic soil in the North China Plain. We believe that the first peak starting at approximately 9:00 am is due to NH3 absorbed by the dew re-emission at night as the dew evaporates. The maximum of ammonia flux at 14:00 corresponds to the peak of soil temperature and solar radiation. The ammonia emission increased rapidly, but the duration of emission peaks lasted approximately 4 d. Cumulative NH3 emission was 25.3% of the applied N over the entire measurement period. The NH3 emissions measured with bLS dispersion technique and venting method had certain difference..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3107 (2012)
Methods of Detector Response Function Establishment in X-Ray Fluorescence Spectra Analysis
LI Zhe, TUO Xian-guo, YANG Jian-bo, LIU Ming-zhe, CHENG Yi, WANG Lei, and ZHOU Jian-bin
During the measurement and analysis process of X-ray fluorescence spectra, it is very helpful to improve the analyze speed, accuracy and automaticity of X-ray fluorescence spectra analysis by establishing detector response function(DRF), which represents the shape of full energy peak and can provide former basic data fDuring the measurement and analysis process of X-ray fluorescence spectra, it is very helpful to improve the analyze speed, accuracy and automaticity of X-ray fluorescence spectra analysis by establishing detector response function(DRF), which represents the shape of full energy peak and can provide former basic data for subsequent X-ray analysis technique. For the theory and model of semiconductor DRF in X-ray energy spectrum measurements, methods of three typical detector response function model establishment, key parameters of full energy peak standard deviation and Fano factor calculation, etc. are discussed, and meanwhile, the summarization and contrast of existing studies are shown in this paper. Finally, the suggestion for modeling methods of DRF in X-ray fluorescence spectra measurements is provided..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3112 (2012)
Determination of Major, Minor and Trace Elements in Soils by Polarized Energy X-Ray Fluorescence Spectrometry and the Application to Vertical Distribution Characteristics of Soil Organic Carbon
SHEN Ya-ting
It is difficult to get accurate, precise and reliable analytical data when using X-ray fluorescence spectrometry (XRF) to determinate sulfur in geological sample. The possible ways to improve sulfur determination accuracy are discussed. Sulfur, and the major, minor and trace elements in soils were determined by polarizIt is difficult to get accurate, precise and reliable analytical data when using X-ray fluorescence spectrometry (XRF) to determinate sulfur in geological sample. The possible ways to improve sulfur determination accuracy are discussed. Sulfur, and the major, minor and trace elements in soils were determined by polarization energy dispersion XRF (EDXRF) spectrometry and the element profiles and vertical distribution were obtained. Based on this, replacement of two short-term vegetation soil profiles was studied. Significant correlations among the vertical distribution of soil organic carbon content (TOC), organic carbon stable carbon isotopes (δ 13C) and several elements were found. The study showed that the EDXRF method can be well applied to element soil geochemical cycle and carbon cycle researches..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3117 (2012)
Texture Variation of DC AA 5052 Aluminum Alloy Slab at Difference Position Through Thickness by XRD
CHEN Ming-biao, LIU Wen-chang, LI Jian, MA Xiao-yi, MA Wen, LIU Chang, LI Jing, DU Wen-wen, and Qi-Sing Man
For improvement the processing and gaining uniformity texture structure and performance the thickness direction of direct chill cast DCAA 5052 aluminum alloy band after first hot rolling with different reduction, the material was annealed at 454 ℃ and then cold rolling with different reduction, we test and examined theFor improvement the processing and gaining uniformity texture structure and performance the thickness direction of direct chill cast DCAA 5052 aluminum alloy band after first hot rolling with different reduction, the material was annealed at 454 ℃ and then cold rolling with different reduction, we test and examined the texture at surface, quarter and center layer of the sample by use X-ray diffraction method, we calculated the data by use special software and analyses the difference texture at surface, quarter and center layer. The intension gradient of β texture was along the direction from surface to center layer gradually enhance at different reduction sample. For β texture, the intension gradient was along the direction from surface to center layer gradually reduce, the volume fraction gradually augment and the intensity gradually were almost equal with the cold rolling reduction increased from 0% to 90%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3123 (2012)
Study on the Method of Nanometer-Size Zirconium Dioxide Enrichment Separation and Inductively Coupled Plasma Mass Spectrometry Determination of Trace Barium(Ⅱ) in Water
DU Ying-qiu, YIN Yi-dong, FAN Nai-ying, CHEN Peng-gang, ZHANG Xiao-bo, REN Hong-bo, CHEN Guo-you, QU Qiu-yao, SUN Zhi-bo, and CHEN Yue-xin
Monoclinic fusiform zirconium dioxide (ZrO2) nanoparticles were synthesized by hydrothermal method, a method was established based on monoclinic fusiform nanometer-sized ZrO2 enrichment separation, and trace barium in water was determined by inductively coupled plasma mass spectrometry（ICP-MS）. The detection limit for Monoclinic fusiform zirconium dioxide (ZrO2) nanoparticles were synthesized by hydrothermal method, a method was established based on monoclinic fusiform nanometer-sized ZrO2 enrichment separation, and trace barium in water was determined by inductively coupled plasma mass spectrometry（ICP-MS）. The detection limit for Ba(Ⅱ) was 0.007 ng·mL-1, and the relative standard deviation was 0.13%（n=11）. The optimal enrichment separation conditions of nanometer-sized ZrO2 for Ba(Ⅱ) were studied in detail, it was found that the percentage of adsorbed Ba(Ⅱ) was more than 99% under pH 10.0 and 2 mL 0.5 mol·L-1 HCl was sufficient for elution of Ba(Ⅱ) by more than 98%. The static adsorption capacity of ZrO2 to Ba(Ⅱ) was 196.6 μg·g-1 and enrichment factor was 250. Properties of nanometer-sized ZrO2 were discussed through regeneration experiment and effects of co-existing ions and contrast experiment to ordinary ZrO2, adsorption properties of nanometer-sized ZrO2 were applied to real samples in the analysis of Ba(Ⅱ) and the determination was carried out by ICP-MS with satisfactory results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3129 (2012)
Study on Allocation Rules of Common Nutrients in Scutellaria Baicalensis in Different Phenological Periods by ICP-OES
LI Hua, LI Wei, ZENG Jie, and YANG Bin
To study the allocation rules of the nutrients in scutellaria baicalensis in different phenological periods, ICP-OES analytical technique was used to measure the contents of 4 elements （Ca, Mg, P and K） in roots, stems, leaves, flowers and fruids in different phenological periods（such as dormancy period, leaf expansionTo study the allocation rules of the nutrients in scutellaria baicalensis in different phenological periods, ICP-OES analytical technique was used to measure the contents of 4 elements （Ca, Mg, P and K） in roots, stems, leaves, flowers and fruids in different phenological periods（such as dormancy period, leaf expansion period, blooming period, fruit maturation period and yellow period） simultaneously. The results indicated that the allocation of Ca, Mg and K in leaves was higher than in the other organs in the vegetative stage, in order to stimulate photosynthesis and generate abundant carbohydrate; there was a larger proportion of P and K in reproductive organ compared with vegetative ones in reproductive stage, and it was beneficial to multiplication, and in yellow period the percentages of Ca, Mg, and K in roots rose slightly to strengthen cold-resistant ability. This study results can help develop scientific and rational fertilization programmes for the cultivation of scutellaria baicalensis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3135 (2012)
Determination of Heavy Metals in Ceramic Food Packaging Containers by ICP-MS
DONG Zhan-hua, LU Li-xin, and LIU Zhi-gang
The direct determination method of heavy metals, Pb, Cd, Cr, Co, Ni, Zn, As and Sb in food packaging ceramics was studied by using inductive coupled plasma mass spectrometry (ICP-MS). Factors influencing the determination were also studied in detail. By choosing the optional operating parameters and appropriate isotopeThe direct determination method of heavy metals, Pb, Cd, Cr, Co, Ni, Zn, As and Sb in food packaging ceramics was studied by using inductive coupled plasma mass spectrometry (ICP-MS). Factors influencing the determination were also studied in detail. By choosing the optional operating parameters and appropriate isotopes of the element to be detected, the influence of mass spectrometry interference was conquered effectively. The detection limits were 0.023 μg·L -1 for Pb, 0.004 μg·L -1 for Cd, 0.030 μg·L -1 for Cr, 0.025 μg·L -1 for Ni, 0.012 μg·L -1 for Sb, 0.180 μg·L -1 for Zn, 0.017 μg·L -1 for As, and 0.002 μg·L -1 for Co. The recovery rates of the method were between 95.8% and 104.4%. The RSDs were between 1.1% and 3.3%. The method was simple, rapid, precise, convenient and suitable for daily inspection of import and export ceramic ware..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3139 (2012)
Measurement and Comparison of Zn, Fe, Cu, Mn, Cr, Pb and Cd in Rabbit Liver of High-Adipose Group and Normal Group
WU Yun-kai, CAO Hong, MAO Chang-jie, GU Zhi-hong, and WANG Yuan
The objective of the present paper is to explore the experimental changes in the content of Zn, Fe, Cu, Mn, Cr, Pb and Cd in white rabbit liver with atherosclerosis disease. The method is to reproduce white rabbit liver with atherosclerosis disease by a high-fat diet, and then measure the Zn, Fe, Cu, Mn, Cr, Pb and Cd The objective of the present paper is to explore the experimental changes in the content of Zn, Fe, Cu, Mn, Cr, Pb and Cd in white rabbit liver with atherosclerosis disease. The method is to reproduce white rabbit liver with atherosclerosis disease by a high-fat diet, and then measure the Zn, Fe, Cu, Mn, Cr, Pb and Cd content with atomic absorption spectrometry. Results show that the Zn, Fe, Cu, Mn, Cr, Pb and Cd contents in the fodders of the normal group are 137.6, 362.3, 14.39, 9.599 mg·kg-1 and 159.3, 355.0, 290.0 μg·kg-1, and 86.09, 277.1, 11.07, 5.366 mg·kg-1 and 115.2, 286.0, 210.5 μg·kg-1, in high-adipose group. It was concluded that Zn, Fe, Cu, Mn, Cr, Pb and Cd contents in white rabbit liver decline, which may have something to do with the intake of foods and the abnormalities of lipoprotein metabolism..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3142 (2012)
A Trace Methane Gas Sensor Using Mid-Infrared Quantum Cascaded Laser at 7.5 μm
CHEN Chen, DANG Jing-min, HUANG Jian-qiang, YANG Yue, and WANG Yi-ding
Presented is a compact instrument developed for in situ high-stable and sensitive continuous measurement of trace gases in air, with results shown for ambient methane (CH4) concentration accurate, real-time and in-situ. This instrument takes advantage of recent technology in thermoelectrically cooling(TEC) pulsed FabryPresented is a compact instrument developed for in situ high-stable and sensitive continuous measurement of trace gases in air, with results shown for ambient methane (CH4) concentration accurate, real-time and in-situ. This instrument takes advantage of recent technology in thermoelectrically cooling(TEC) pulsed Fabry-Perot (FP) quantum cascaded laser (QCL) driving in a pulse mode operating at 7.5 μm ambient temperature to cover a fundamental spectral absorption band near ν4 of CH4. A high quality Liquid Nitrogen (LN) cooled Mercury Cadmium Telluride (HgCdTe) mid-infrared (MIR) detector is used along with a total reflection coated gold ellipsoid mirror offering 20 cm single pass optical absorption in an open-path cell to achieve stability of 5.2×10-3 under experimental condition of 200 μmol·mol-1 measured ambient CH4. The instrument integrated software via time discriminating electronics technology to control QCL provides continuous quantitative trace gas measurements without calibration. The results show that the instrument can be applied to field measurements of gases of environmental concern. Additional, operator could substitute a QCL operating at a different wavelength to measure other gases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3146 (2012)
The Principle and Analysis of Micro-Fourier Transform Spectrometer Based on MEMS Micro-Mirror
CHEN Jian-jun, ZHU Yong, LIU Bo, WEI Wei, ZHANG Jie, and WANG Ning
The present paper puts forward a novel micro-Fourier transform infrared spectrometer based on programmable MEMS micro-mirror. This design uses a MEMS micro-mirror and a slantwise reflector to replace the moving mirror system on traditional spectrometer. This paper analyzes the operating principle of this spectrometer aThe present paper puts forward a novel micro-Fourier transform infrared spectrometer based on programmable MEMS micro-mirror. This design uses a MEMS micro-mirror and a slantwise reflector to replace the moving mirror system on traditional spectrometer. This paper analyzes the operating principle of this spectrometer and gives the simulation result to prove the feasibility of this method. The results show that the spectral resolution is less than 5 nm in near-infrared wave band, the wavelength accuracy is approximately 1 nm and the sampling period of this spectrometer is approximately 50 ms. This method can use Hadamard transform to improve the SNR..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3151 (2012)
Compression of Interference Hyperspectral Image Based on FHALS-NTD
DU Li-min, LI Jin, JIN Guang, GAO Hui-bin, JIN Long-xu, and ZHANG Ke
A hyperspectral interference image compression algorithm based on fast hierarchical alternating least squares nonnegative tensor Tucker decomposition (FHALS-NTD) is proposed. Firstly, the interference hyperspectral image is decomposed by 3-D OPD lifting-based discrete wavelet transform (3D OPT-LDWT) in the OPD directioA hyperspectral interference image compression algorithm based on fast hierarchical alternating least squares nonnegative tensor Tucker decomposition (FHALS-NTD) is proposed. Firstly, the interference hyperspectral image is decomposed by 3-D OPD lifting-based discrete wavelet transform (3D OPT-LDWT) in the OPD direction. Then, the 3D DWT sub-bands decomposed are used as a three order nonnegative tensor, which is decomposed by the proposed FHALS-NTD algorithm to obtain 8 core tensors and 24 unknown component matrices. Finally, to obtain the final compressed bit-stream, each unknown component matrices element is quantized, and each core tensor is encoded by the proposed bit-plane coding of significant coefficients. The experimental results showed that the proposed compression algorithm could be used for reliable and stable work and has good compressive property. In the compression ratio range from 32∶1 to 4∶1, the average peak signal to noise ratio of proposed compression algorithm is higher than 40 dB. Compared with traditional approaches, the proposed method could improve the average PSNR by 1.23 dB. This effectively improves the compression performance of hyperspectral interference image..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3155 (2012)
Performance Analysis And Radiometric Correction of Novel Molecular Hyperspectral Imaging System
LIU Hong-ying, LI Qing-li, GU Bin, WANG Yi-ting, and XUE Yong-qi
Integrating molecular imaging technology and hyperspectral technology, a novel molecular hyperspectral imaging (MHSI) system based on AOTF was presented. The system consists of microscope, spectrometer, matrix CCD, image collection card and computer. The system’s performance was synthetically evaluated referring every Integrating molecular imaging technology and hyperspectral technology, a novel molecular hyperspectral imaging (MHSI) system based on AOTF was presented. The system consists of microscope, spectrometer, matrix CCD, image collection card and computer. The system’s performance was synthetically evaluated referring every part’s performance. The spectral range of the MHSI system is from 550 to 1 000 nm. Two hundred twenty five bands can be continuously captured at a time. The spectral resolution is less than 2 nm. The spatial resolution is about 0.061 5 μm. CCD acquisition speed achieved 2.612 5 s·B-1 in the integration mode and about 0.11 μs·B-1 in the non-integration mode. Due to the infection of lamp, a spectral curve extracted directly from the original hyperspectral data can not truly present biochemical character and needs to be corrected. The paper proposes the gray correction coefficient algorithm with spatial dimension and spectral dimension, and gives concrete realization of the algorithm. Taking the sample of leukemia blood, by comparing the single-band images, pseudo-color images and spectra before and after correction, the results indicate the effectiveness of correction algorithm. The corrected data is effective for subsequent analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 3161 (2012)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 11, 1 (2012)
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