Journals >Spectroscopy and Spectral Analysis
Contents
2015
Volume: 35 Issue 10
56 Article(s)
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Research Article
Multispectral Radiation Algorithm Based on Emissivity Model Constraints for True Temperature Measurement
LIANG Mei, SUN Xiao-gang, and LUAN Mei-sheng
Temperature measurement is one of the important factors for ensuring product quality, reducing production cost and ensuring experiment safety in industrial manufacture and scientific experiment. Radiation thermometry is the main method for non-contact temperature measurement. The second measurement (SM) method is one oTemperature measurement is one of the important factors for ensuring product quality, reducing production cost and ensuring experiment safety in industrial manufacture and scientific experiment. Radiation thermometry is the main method for non-contact temperature measurement. The second measurement (SM) method is one of the common methods in the multispectral radiation thermometry. However, the SM method cannot be applied to on-line data processing. To solve the problems, a rapid inversion method for multispectral radiation true temperature measurement is proposed and constraint conditions of emissivity model are introduced based on the multispectral brightness temperature model. For non-blackbody, it can be drawn that emissivity is an increasing function in the interval if the brightness temperature is an increasing function or a constant function in a range and emissivity satisfies an inequality of emissivity and wavelength in that interval if the brightness temperature is a decreasing function in a range, according to the relationship of brightness temperatures at different wavelengths. The construction of emissivity assumption values is reduced from multiclass to one class and avoiding the unnecessary emissivity construction with emissivity model constraint conditions on the basis of brightness temperature information. Simulation experiments and comparisons for two different temperature points are carried out based on five measured targets with five representative variation trends of real emissivity: decreasing monotonically, increasing monotonically, first decreasing with wavelength and then increasing, first increasing and then decreasing and fluctuating with wavelength randomly. The simulation results show that compared with the SM method, for the same target under the same initial temperature and emissivity search range, the processing speed of the proposed algorithm is increased by 19.16%~43.45% with the same precision and the same calculation results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2675 (2015)
Spectroscopic Diagnosis of Two-Dimensional Distribution of OH Radicals in Wire-Plate Pulsed Corona Discharge Reactor
JIANG Jian-ping, LUO Zhong-yang, XUAN Jian-yong, ZHAO Lei, FANG Meng-xiang, and GAO Xiang
Pulsed corona discharge in atmosphere has been widely regarded as an efficient flue gas treatment technology for the generation of active radical species, such as the OH radicals. The spatial distribution of OH radicals generated by pulsed corona discharge plays an important role in decomposing pollutants. The two-dimePulsed corona discharge in atmosphere has been widely regarded as an efficient flue gas treatment technology for the generation of active radical species, such as the OH radicals. The spatial distribution of OH radicals generated by pulsed corona discharge plays an important role in decomposing pollutants. The two-dimensional (2-D) distribution of OH radicals of positive wire–plate pulsed corona discharge was detected using laser-induced fluorescence (LIF). The influence of relative humidity (RH) and oxygen concentration on the 2-D distribution of OH radicals were investigated. The results indicated that the 2-D distribution of OH radicals was characterized by a fan-shaped distribution from the wire electrode to plate electrode, and both the maximum values of vertical length and horizontal width of the fan area was less than 1 cm. The 2-D distribution area of OH radicals increased significantly with increasing the RH and the optimum condition was 65% RH. The optimal level of the oxygen concentration for the 2-D distribution area of OH radicals was 2%. The process of OH radical generation and 2-D distribution area of OH radicals were significantly interfered when the oxygen concentration was larger than 15%. The total quenching rate coefficients for different RH values and oxygen concentration in this study were used to calculate the fluorescence yield of OH radical. The fluorescence yield, which is the ratio between the emission rate (Einstein coefficient) and the sum of the emission rate and quenching rate, was used to normalize the 2-D distribution area of OH radicals. The fluorescence yield of OH radical decreased with increasing the RH and oxygen concentration linearly and rapidly. It was also found that compared with the RH, the influence of the oxygen concentration had more notable effect on the fluorescence yield of OH radical and 2-D distribution area of OH radicals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2680 (2015)
The Performance Analysis for Lighting Sources in Highway Tunnel Based on Visual Function
YANG Yong, HAN Wen-yuan, YAN Ming, JIANG Hai-feng, and ZHU Li-wei
Under the condition of mesopic vision, the spectral luminous efficiency function is shown as a series of curves. Its peak wavelength and intensity are affected by light spectrum, background brightness and other aspects. The impact of light source to lighting visibility could not be carried out via a single optical paraUnder the condition of mesopic vision, the spectral luminous efficiency function is shown as a series of curves. Its peak wavelength and intensity are affected by light spectrum, background brightness and other aspects. The impact of light source to lighting visibility could not be carried out via a single optical parametric characterization. The reaction time of visual cognition is regard as evaluating indexes in this experiment. Under the condition of different speed and luminous environment, testing visual cognition based on vision function method. The light sources include high pressure sodium, electrodeless fluorescent lamp and white LED with three kinds of color temperature (the range of color temperature is from 1 958 to 5 537 K). The background brightness value is used for basic section of highway tunnel illumination and general outdoor illumination, its range is between 1 and 5 cd·m-2. All values are in the scope of mesopic vision. Test results show that: under the same condition of speed and luminance, the reaction time of visual cognition that corresponding to high color temperature of light source is shorter than it corresponding to low color temperature; the reaction time corresponding to visual target in high speed is shorter than it in low speed. At the end moment, however, the visual angle of target in observer’s visual field that corresponding to low speed was larger than it corresponding to high speed. Based on MOVE model, calculating the equivalent luminance of human mesopic vision, which is on condition of different emission spectrum and background brightness that formed by test lighting sources. Compared with photopic vision result, the standard deviation (CV) of time-reaction curve corresponding to equivalent brightness of mesopic vision is smaller. Under the condition of mesopic vision, the discrepancy between equivalent brightness of different lighting source and photopic vision, that is one of the main reasons for causing the discrepancy of visual recognition. The emission spectrum peak of GaN chip is approximate to the wave length peak of efficiency function in photopic vision. The lighting visual effect of write LED in high color temperature is better than it in low color temperature and electrodeless fluorescent lamp. The lighting visual effect of high pressure sodium is weak. Because of its peak value is around the Na+ characteristic spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2686 (2015)
Research on Properties of Light Scattering for Non-Spherical Suspended Particles in Water Based on T Matrix Model
Vo Quang Sang, FENG Peng, MI De-ling, TANG Bin, and WEI Biao
Scattering light properties of suspended particles in water is an important parameter which influences the accuracy of water quality measurement. In this paper, based on T matrix model, the authors study the UV-Visible light irradiation intensity of 3 kinds of non-spherical suspended particles including ellipsoid, cyliScattering light properties of suspended particles in water is an important parameter which influences the accuracy of water quality measurement. In this paper, based on T matrix model, the authors study the UV-Visible light irradiation intensity of 3 kinds of non-spherical suspended particles including ellipsoid, cylinder and generalized Chebyshev in water. The relationship between light scattering intensity and incident light wavelength, shape parameters of suspended particles, complex refractive index and rotation angle has been presented in detail. Simulation results show that when changing the particle size, adjusting the wavelength of incident light, all light scattering intensity of 3 kinds of non-spherical suspended particles show significant changes. In the wavelength range from 200～800 nm, the impact of geometric on the particles size decreases with increasing wavelength and the sattering properites mainly depends on complex refractive index. The scattering intensity becomes stronger and exhibits strong oscillations for ultraviolet and infrared light when the diameter of particles are less than 0.2 μm or approaching 1 μm. However, the scattering intensity is relatively stable and close to zero, shows small disturbances with the change of wavelength of incident light when the particles sizes are within 0.3 to 0.9 μm.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2691 (2015)
Reconstruction Research for Gas Concentration and Temperature of Flame Based on Algebraic Reconstruction Technique
XIA Hui-hui, LIU Jian-guo, XU Zhen-yu, KAN Rui-feng, HE Ya-bai, ZHANG Guang-le, and CHEN Jiu-ying
We specify water vapor among combustion products as the target gas based on tunable diode absorption spectroscopy in this paper. The direct absorption signals of water vapor after being processed can be used to calculate the gas concentration distributions and temperature distributions of the combustion region of methaWe specify water vapor among combustion products as the target gas based on tunable diode absorption spectroscopy in this paper. The direct absorption signals of water vapor after being processed can be used to calculate the gas concentration distributions and temperature distributions of the combustion region of methane and air flat flame furnace via algebraic reconstruction technique (ART). In the numerical simulation, reconstruction region is a grid of five by five, we assume a temperature and water vapor concentration distribution of 25 grid, then simulate different direction laser rays which cross the combustion region, generating projection of each ray, by ART reconstruction algorithm, it turns out that the temperature and water vapor distribution reconstruction error is less than 1%. In the experiment, we chose a distributed-feedback laser to scan the target gas H2O 7 153.722, 7 153.748 and 7 154.354 cm-1 as absorbtion line pair to measure temperature of the flame, we consider the former two line as one absorbtion line. By Stages multi-directional scanning, the authors abtain 16 different regions distributin of temperature and gas concentration of furnace when we collecte 30 different angle data by spectral data processing, reconstruction algorithm, two absorbtion line ratio method for temperature sensing, finding the temperature and water concentration are higher in the center than in the edge, it turns out that the reconstruction algorithm is good enough to achieve the distributions of gas concentration and temperature of the combustion region..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2697 (2015)
Investigation on Spectral Characteristics of Micro-Gap Dielectric Barrier Uniform Discharge in Air
HAN Yu-hong, JIA Peng-ying, HE Shou-jie, and ZHANG Zi-sheng
The plasmas generated by dielectric barrier discharge in atmospheric pressure air have wide application prospect in industry. In order to study generation condition and mechanism, the dielectric barrier uniform discharge in atmospheric pressure air has been studied experimentally with a micro-gap discharge device. ResuThe plasmas generated by dielectric barrier discharge in atmospheric pressure air have wide application prospect in industry. In order to study generation condition and mechanism, the dielectric barrier uniform discharge in atmospheric pressure air has been studied experimentally with a micro-gap discharge device. Results of electrical characteristics indicate that it exist several current pulses with short width in half period of the applied voltage at a low voltage, a large number of micro-discharge filaments are observed. The discharge power increases with increasing peak value of applied voltage, the micro-discharge filaments increase meanwhile. When the peak of applied voltage reaches to 9.2 kV, only a discharge hump with a width of about 5.5 μs appears in a half period of the applied voltage, micro-discharge filaments cannot be discerned. The uniform discharge has been obtained finally as the micro-discharge filaments extend and superimpose randomly. The emission spectrum of dielectric barrier discharge scanning from 330 to 420 nm is collected. It is found that the intensity of 337.1 nm is stronger than that of 391.4 nm. If the intensity of 337.1 nm is considered as the datum reference, the intensity of 391.4 nm shows the magnitude of electron average energy. The molecule internal energy is evaluated by vibration temperature. The electron average energy and molecule internal energy have been investigated by optical emission spectra. It is found that both of them decrease with increasing the applied voltage. Results indicate that it is not easy to form filamentary discharge when the electrical energy is lower. The average electron energy of uniform discharge is lower than that of the filamentary discharge. These results are of great significance to the application of dielectric barrier uniform discharge obtained in air at atmospheric pressure..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2703 (2015)
Study on Spectral Characteristics of Micro Plasma Channels of Different Gas-Gap in Dielectric Barrier Discharge
GAO Ye-nan, DONG Li-fang, and LIU Ying
By optical emission spectrum, we report on the first investigation on the plasma parameters of micro plasma channels which are generated in two gas-gaps with different thickness in a triple-layer dielectric barrier discharge system. Different from the micro plasma channels formed in traditional two-layer dielectric barBy optical emission spectrum, we report on the first investigation on the plasma parameters of micro plasma channels which are generated in two gas-gaps with different thickness in a triple-layer dielectric barrier discharge system. Different from the micro plasma channels formed in traditional two-layer dielectric barrier discharge, micro plasma channels formed in the triple-layer dielectric barrier discharge system reflect a unique discharge characteristic. From the pattern images taken by an ordinary camera, it shows that micro plasma channels generated in two discharge gas-gaps discharge with different sizes and light intensities. The micro plasma channels in wide gas-gap are much bigger than those in narrow gas-gap, and their light intensities are obvious stronger. By collecting the emission spectra of N2 second positive band (C3Πu→B3Πg) and calculating the relative intensity ratio method of N2 molecular ion line at 391.4 and the N2 molecular line at 394.1, the molecular vibration temperature and the average electron energy of micro plasma channels in two gas-gaps as functions of Argon concentration and applied voltage are investigated, respectively. It is found that the molecular vibration temperature and the average electron energy of micro plasma channels in wide gas-gap are lower than those in narrow gas-gap, and they both decrease with the increasing of the Argon concentration. As the applied voltage increases, micro plasma channels in wide gas-gap vary in a small range on the above two plasma investigations, while those in narrow gas-gap vary obviously. It indicates that micro plasma channels in narrow gas-gap are more sensitive to the applied voltage and they have a wider variation range of electric field than those in wide gas-gap..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2708 (2015)
The Synthesis, Luminescence and Energy Transmission of NaLa(MoO4)2∶Eu3+/Tb3+/Tm3+ Materials
XU Jing, YAN Jing-hui, HAN Yu-ting, QIAO Shu-liang, YANG Bo, LI Li, LIU Cai-hong, YAO Shuang, and ZOU Ming-qiang
A series of Eu3+/Tb3+/Tm3+ single/co-doped NaLa(MoO4)2 (NLM) phosphors have been synthesized by microemulsion-hydrothermal method. Phosphor crystal structure, morphology and luminescent properties were tested and studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy. The rA series of Eu3+/Tb3+/Tm3+ single/co-doped NaLa(MoO4)2 (NLM) phosphors have been synthesized by microemulsion-hydrothermal method. Phosphor crystal structure, morphology and luminescent properties were tested and studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy. The results show that the prepared samples are all tetragonal single crystals. By way of substitution, the sites of La3+ are replaced by Eu3+, Tb3+and Tm3+. Morphology of the samples are tetragonal sheet structure and the size of particles is 1~1.5 μm. When the doping concentration of Eu3+ is 9%, NLM∶9%Eu3+ phosphor emission peak is the strongest at 616 nm, the critical transfer distance (Rc) between Eu3+ in the NLM matrix is about 15.20 at this time. At the emission spectrum of NLM∶9%Eu3+, the peak at 591 nm is the magnetic dipole transition of 5D0 to 7F1 of Eu3+. The peak at 616 nm is the electric dipole transition of 5D0 to 7F2 of Eu3+. Electric dipole transition emission intensity is about 10 times of the strength of the magnetic dipole transition. This indicates that Eu3+ is located at noninversion symmetry site. By Fixing Eu3+ (Tb3+) concentration and varying the concentration of Tb3+ (Eu3+), the energy transfer mechanism between Eu3+ and Tb3+ was studied. By adjusting the Eu3+, Tb3+and Tm3+ doping concentrations, tunable luminescence of visible light region is implemented under the single matrix. The luminescence of NLM∶x%Eu3+, y%Tb3+, z%Tm3+ phosphors are translated from blue (0.205, 0.135) to pseudo-white (0.305, 0.266) under 360 nm irradiation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2712 (2015)
The Influence of Different Ionic Concentration in Cell Physiological Solution on Temperature Measurement by Near Infrared
ZHENG Yu, CHEN Xiong, ZHOU Mei, WANG Meng-jun, WANG Jin-hai, LI Gang, and CUI Jun
It is important to real-timely monitor and control the temperature of cell physiological solution in patch clamp experiments, which can eliminate the uncertainty due to temperature and improve the measurement accuracy. This paper studies the influence of different ions at different concentrations in the physiological sIt is important to real-timely monitor and control the temperature of cell physiological solution in patch clamp experiments, which can eliminate the uncertainty due to temperature and improve the measurement accuracy. This paper studies the influence of different ions at different concentrations in the physiological solution on precision of a temperature model by using near infrared spectroscopy and chemometrics method. Firstly, we prepared twelve sample solutions respectively with the solutes of CaCl2, KCl and NaCl at four kinds of concentrations, and collected the spectra of different solutions at the setting temperature range 20~40 ℃, the range of the spectra is 9 615~5 714 cm-1. Then we divided the spectra of each solution at different temperatures into two parts (a training set and a prediction set) by three methods. Interval partial least squares method was used to select an effective wavelength range and develop calibration models between the spectra in the selected range and temperature velues. The experimental results show that RMSEP of CaCl2 solution with 0.25 g·mL-1 is maximum, the result of the three tests are 0.386 3, 0.303 7 and 0.337 2℃, RMSEP of NaCl with 0.005 g·mL-1 solution is minimum, the result of the three tests are 0.220 8, 0.155 3 and 0.145 2 ℃. The experimental results indicate that Ca2+ has the greatest influence on the accuracy of the temperature model of the cell physiological solution, then K+, and Na+ has the least influence. And with the ionic concentration increasing, the model accuracy decreases. Therefore, when we build the temperature model of cell physiological solution, it is necessary to change the proportion of the three kinds of main ions in cell physiological solution reasonably in order to correct the effects of different ionic concentrations in physiological solution and improve the accuracy of temperature measurements by near infrared spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2718 (2015)
Preliminary Study on the Unique Spectroscopic Characteristics of Natural and Synthetic Diamonds
YAN Jun, WANG Xiao-xiang, TAO Jin-bo, ZHANG Jian, and HU Xian-chao
A systematic comparative study on the natural diamond, the natural diamond treated by heat or irradiation and synthetic diamond prepared by chemical vapor deposition (CVD) or High temperature and high pressure (HTHP) were carried out by UV-Vis-NIR absorption and FTIR spectra. The results showed that: natural diamond, tA systematic comparative study on the natural diamond, the natural diamond treated by heat or irradiation and synthetic diamond prepared by chemical vapor deposition (CVD) or High temperature and high pressure (HTHP) were carried out by UV-Vis-NIR absorption and FTIR spectra. The results showed that: natural diamond, treated natural samples such as irradiated or annealed ones under high temperature and the HTHP synthetic diamond, the reflection coefficient is obviously variation between 200 nm and 1100 nm in UV-Vis-NIR spectra of above samples. In contrast, the reflection coefficient of CVD synthetic diamond is relatively smaller than the former. Infrared spectra showed that synthetic diamonds, especially for CVD synthetic diamonds have no obvious absorption peak between 800 and 1 600 cm-1. In additional, the results of DiamondViewTM detection are different for different kinds of diamonds. Generally speaking, some CVD synthetic diamonds treated by HTHP appears some parallel dislocation lines, and show light-blue fluorescence. HPHT synthetic diamonds exhibit strong blocky geometrical shapes whereas some natural diamonds exhibit more tree-ring type fluorescence patterns, the color of diamonds’ fluorescence image may change after treated by HTHP or irradiation. In a word, in view of the diversity and innovation of the synthesis technologies for diamond, the natural and synthetic diamonds have some similar spectra characteristic in term of UV-Vis-NIR and FTIR spectra, some special natural diamonds without typical spectra characteristic of natural ones need to be further supplemented with DiamondViewTM, photoluminescence spectra and other instruments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2723 (2015)
Study on the Application of NAS-Based Algorithm in the NIR Model Optimization
GENG Ying, XIANG Bing-ren, and HE Lan
In this paper, net analysis signal (NAS)-based concept was introduced to the analysis of multi-component Ginkgo biloba leaf extracts. NAS algorithm was utilized for the preprocessing of spectra, and NAS-based two-dimensional correlation analysis was used for the optimization of NIR model building. Simultaneous quantitaIn this paper, net analysis signal (NAS)-based concept was introduced to the analysis of multi-component Ginkgo biloba leaf extracts. NAS algorithm was utilized for the preprocessing of spectra, and NAS-based two-dimensional correlation analysis was used for the optimization of NIR model building. Simultaneous quantitative models for three flavonol aglycones: quercetin, keampferol and isorhamnetin were established respectively. The NAS vectors calculated using two algorithms introduced from Lorber and Goicoechea and Olivieri (HLA/GO) were applied in the development of calibration models, the reconstructed spectra were used as input of PLS modeling. For the first time, NAS-based two-dimensional correlation spectroscopy was used for wave number selection. The regions appeared in the main diagonal were selected as useful regions for model building. The results implied that two NAS-based preprocessing methods were successfully used for the analysis of quercetin, keampferol and isorhamnetin with a decrease of factor number and an improvement of model robustness. NAS-based algorithm was proven to be a useful tool for the preprocessing of spectra and for optimization of model calibration. The above research showed a practical application value for the NIRS in the analysis of complex multi-component petrochemical medicine with unknown interference..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2730 (2015)
Detection of Syrup Adulterants in Prepackaged Pure Pineapple Juice by Fourier-Transform Infrared Spectroscopy and Chemometric Analysis
ZHOU Mi, KE Jian, LI Bao-li, TANG Cui-e, TAN Jun, LIU Rui, WANG Hong, LI Tao, and ZHOU Sheng-yin
This study was performed to establish a method that can quickly and accurately identify adulterated syrup in the pure pineapple juice. A attenuated total internal refraction-fourier transform infrared spectroscopy was used to collect the range of 900～1 500 cm-1 infrared spectra of 234 samples pure pineapple juice and aThis study was performed to establish a method that can quickly and accurately identify adulterated syrup in the pure pineapple juice. A attenuated total internal refraction-fourier transform infrared spectroscopy was used to collect the range of 900～1 500 cm-1 infrared spectra of 234 samples pure pineapple juice and adulterated syrup by beet syrup, rice syrup and cassava syrup. By using linear discriminant analysis and support vector machine for the identification model, comparing the full spectral and selected wavelengths based on principal component analysis loading plots of the two models to identify adulteration. Studies showed that the correct rate of validation set by linear discriminant analysis and support vector machine model on full spectral were both higher than 88%, variables were significantly reduced from 312 to 8 after selecting the eight characteristic wavelengths, the correct rate of validation set by linear discriminant analysis model was up to 96.15% and support vector machine was increase to 94.87%. The results demonstrated that the model built using a attenuated total internal refraction-fourier transform infrared spectroscopy in combination with chemometric methods after selected characteristic wavelengths could be used for the identification of the adulterated syrup in the pure pineapple juice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2734 (2015)
Study on Trace Water Influence on Electrical Properties of Insulating Oil Based on the Mid-Infrared Spectrum Analysis
CHEN Bin, WU Hong-yang, HAN Chao, YAN Huan, and LIU Ge
Trace water has a significant impact on the electrical performances of the insulating oil, such as the dielectric loss factor, resistivity. So there is an important significance to investigate the influence of insulating oil by trace water, and monitor its operating status with effective measures. First, it is necessarTrace water has a significant impact on the electrical performances of the insulating oil, such as the dielectric loss factor, resistivity. So there is an important significance to investigate the influence of insulating oil by trace water, and monitor its operating status with effective measures. First, it is necessary to prepare the insulating oil samples with different water content and treat them 8 hours with ultrasonic oscillator, and observe microscopic images about the water-oil mixtures in order to study their relative uniformity and stable time, in the way it can be concluded that the relative uniformity can be kept favorable during the 25 min stable time for free water and emulsification water in oil; Based on this conclusion, the dielectric loss factor, resistivity were tested and the electrical performances of insulating oil with different water content in oil can obtained by analyzing these data; Then, the absorbance value of the different water content in oil at the spectral wave number of 1 640, 3 400, 3 450, 3 615 cm-1, with the mid-infrared spectral scanning and analyzing to the different water content in oil, Therefore, combined the water absorbance values by the mid-infrared spectral scanning and analyzing with the experimental data of dielectric loss factor value, resistivity value of oil samples. The results shows that the absorbance value of the different water content in oil has a significant difference at the spectral wave number of 1 640, 3 400, 3450, 3 615 cm-1, their correlation coefficient are 0.964 1, 0.984 8, 0.984 5, 0.944 0 between the absorbance value and water content at the spectral wave number of 1 640, 3 400, 3 450, 3 615 cm-1, it can be obtained that the absorbance value of sample of moisture in the corresponding characteristic wave number can better reflect the change trend of water content; there is the highly relative of water absorbance values at the spectral wave number of 3 400 and 3 450 cm-1 with the trends of oil dielectric loss factor values, their correlation coefficient are 0.860 6, 0.863 6; and relative of water absorbance values at the spectral wave number of 1 640 and 3 615 cm-1 with the trends of oil resistivity values, their correlation coefficient is -0.931 5 and -0.968 0, this result can be lay the foundation research for monitoring the trace water in oil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2740 (2015)
EEMD-ICA Applied in Signal Extraction in Functional Near-Infrared Spectroscopy
ZHA Yu-tong, LIU Guang-da, ZHOU Run-dong, ZHANG Xiao-feng, NIU Jun-qi, YU Yong, and WANG Wei
Currently, functional near-infrared spectroscopy (fNIRS) is widely used in the field of Neuroimaging. To solve the signal-noise frequency spectrum aliasing in non-linear and non-stationary fNIRS characteristic signal extraction, a new joint multi-resolution algorithm, EEMD-ICA, is proposed based on combining IndependenCurrently, functional near-infrared spectroscopy (fNIRS) is widely used in the field of Neuroimaging. To solve the signal-noise frequency spectrum aliasing in non-linear and non-stationary fNIRS characteristic signal extraction, a new joint multi-resolution algorithm, EEMD-ICA, is proposed based on combining Independent Component Analysis with Ensemble Empirical Mode Decomposing. After functional brain imaging instrument detected the multi-channel and multi-wavelength NIR optical density signals, EEMD was performed to decompose measurement signals into multiple intrinsic mode function according to the signal frequency component. Then ICA was applied to extract the interest data from IMFs into ICs. Finally, reconstructed signals were obtained by accumulating the ICs set. EEMD-ICA was applied in de-noising Valsalva test signals which were considered as original signals and compared with Empirical Mode Decomposing and Ensemble Empirical Mode Decomposing to illustrate validity of this algorithm. It is proved that useful information loss during de-noising and invalidity of noise elimination are completely solved by EEMD-ICA. This algorithm is more optimized than other two de-noising methods in error parameters and signal-noise-ratio analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2746 (2015)
Application of NIR Spectroscopy for Nondestructive Qualitative and Quantitative Analysis of Lotus Seeds
ZHU Heng-yin, FU Xia-ping, YOU Gui-rong, and HE Jin-cheng
By extracting the Near Infrared (NIR) diffuse reflectance spectral characteristics from the post-harvest lotus seeds in different storage periods, the quantitative and qualitative analysis were applied to lotus seeds with the Soluble Solids Content (SSC) and dry matter content (DM) as criteria. The results of the PartiBy extracting the Near Infrared (NIR) diffuse reflectance spectral characteristics from the post-harvest lotus seeds in different storage periods, the quantitative and qualitative analysis were applied to lotus seeds with the Soluble Solids Content (SSC) and dry matter content (DM) as criteria. The results of the Partial Least Squares Regression (PLSR) and distance discrimination (DA) models showed that the absorption spectra of lotus seeds and lotus kernels has clear relations to their SSC and DM. The PLSR models of SSC and DM of lotus seeds had the best performance in 5 941～12 480 cm-1 spectral region in this study. Their correlation coefficients of prediction were 0.74 and 0.82, and the correlation coefficients of calibration were 0.82 and 0.84, and the correlation coefficients of leave one out cross validation were 0.72 and 0.71. The PLSR model of SSC of lotus kernels was better in 7 891～9 310 cm-1 spectral region. Its correlation coefficient of prediction was 0.79, and the correlation coefficient of calibration was 0.84, and the correlation coefficient of leave one out cross validation was 0.77. The PLSR model of DM of lotus kernels is better in the full spectral region. Its correlation coefficient of prediction was 0.92, and the correlation coefficient of calibration was 0.89, and the correlation coefficient of leave one out cross validation was 0.82. For lotus seeds, the DA model in 5 400～7 885 cm-1 spectral region is the best with a correctness of 84.2%. And for lotus kernels, the DA model in 9 226～12 480 cm-1 spectral region is the best with a correctness of 90.8%. For dry lotus kernels, the discriminant accuracy of the DA model is 98.9% in the optimal spectral region. All kernels with membrane and plumule were correctly discriminated. This research shows that the NIR spectroscopy technique can be used to determine SSC and DM content of lotus seeds and lotus kernels, as well as to discriminate their freshness and also to discriminate dry lotus kernels of different age and the kernels with membrane and plumule..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2752 (2015)
Rapid Quantitative Analysis of Content of the Additive in Gasoline for Motor Vehicles by Near-Infrared Spectroscopy
RONG Hai-teng, SONG Chun-feng, YUAN Hong-fu, LI Xiao-yu, HU Ai-qin, XIE Jin-chun, and YAN De-lin
A new rapid quantitative method for the determination of oxygenates and the compounds not included in the national standard in gasoline using near-infrared spectroscopy is raised by this paper. This method combine near-infrared spectroscopy with oblique projection. This experiment choose four different types of gasolinA new rapid quantitative method for the determination of oxygenates and the compounds not included in the national standard in gasoline using near-infrared spectroscopy is raised by this paper. This method combine near-infrared spectroscopy with oblique projection. This experiment choose four different types of gasoline, including reconcile gasoline, FCC refined gasoline, reformed gasoline and desulfurizing gasoline. Prepare series gasoline samples containing different concentrations and different types of compounds. Using FTIR spectrometer to measure those samples and got transmission spectrums. Oblique projection method could separate quantity spectral signal from mixed spectrum signal, and using projection to calculate and analyze the separated signal to obtain the content of measured component. The deviation between this method and the real content is low, the absolute error is less than 0.8 and the relative error is less than 8%. For the actual gasoline samples, compare results of this method with gas chromatography, the absolute error are less than 0.85 and the relative error are less than 6.85%. This method solves the problem of general multivariate calibration methods. It is very significant for the development of rapid detection technology using NIR suitable for on-site and the improvement of the quality of gasoline..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2757 (2015)
Rapid Identification of Epicarpium Citri Grandis via Infrared Spectroscopy and Fluorescence Spectrum Imaging Technology Combined with Neural Network
PAN Sha-sha, HUANG Fu-rong, XIAO Chi, XIAN Rui-yi, and MA Zhi-guo
To explore rapid reliable methods for detection of Epicarpium citri grandis(ECG), the experiment using Fourier Transform Attenuated Total Reflection Infrared Spectroscopy(FTIR/ATR) and Fluorescence Spectrum Imaging Technology combined with Multilayer Perceptron (MLP) Neural Network pattern recognition, for the identifiTo explore rapid reliable methods for detection of Epicarpium citri grandis(ECG), the experiment using Fourier Transform Attenuated Total Reflection Infrared Spectroscopy(FTIR/ATR) and Fluorescence Spectrum Imaging Technology combined with Multilayer Perceptron (MLP) Neural Network pattern recognition, for the identification of ECG, and the two methods are compared. Infrared spectra and fluorescence spectral images of 118 samples, 81 ECG and 37 other kinds of ECG, are collected.According to the differences in tspectrum, the spectra data in the 550～1 800 cm-1 wavenumber range and 400～720 nm wavelength are regarded as the study objects of discriminant analysis. Then principal component analysis (PCA) is applied to reduce the dimension of spectroscopic data of ECG and MLP Neural Network is used in combination to classify them. During the experiment were compared the effects of different methods of data preprocessing on the model: multiplicative scatter correction (MSC), standard normal variable correction(SNV), first-order derivative(FD), second-order derivative(SD) and Savitzky-Golay (SG). The results showed that:after the infrared spectra data via the Savitzky-Golay (SG) pretreatment through the MLP Neural Network with the hidden layer function as sigmoid, we can get the best discrimination of ECG, the correct percent of training set and testing set are both 100%. Using fluorescence spectral imaging technology, corrected by the multiple scattering (MSC) results in the pretreatment is the most ideal. After data preprocessing, the three layers of the MLP Neural Network of the hidden layer function as sigmoid function can get 100% correct percent of training set and 96.7% correct percent of testing set. It was shown that the FTIR/ATR and fluorescent spectral imaging technology combined with MLP Neural Network can be used for the identification study of ECG and has the advantages of rapid, reliable effect..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2761 (2015)
Source Constraints on Turquoise of the Erlitou Site by Infrared Spectra
REN Jia, YE Xiao-hong, WANG Yan, LUO Shu-qiong, and SHI Guang-hai
Shiyan district in Hubei province is a famous locality of high-quality turquoise with brightcolor, finegrain in the world. Erlitou archaeologicalsite, which is about 300km north to the Shiyan Turquoise mine, has been excavated a remarkable number of turquoise artifacts since 2002. Some researchers infer that there was Shiyan district in Hubei province is a famous locality of high-quality turquoise with brightcolor, finegrain in the world. Erlitou archaeologicalsite, which is about 300km north to the Shiyan Turquoise mine, has been excavated a remarkable number of turquoise artifacts since 2002. Some researchers infer that there was “a road of turquoise” between the two sites in history. In order to check the inference, and identify local features of the turquoises found in Shiyan, and Eelitou site as well, spectra of three turquoise groups from Shiyan, Hubei and one group of Erlitou unearthed samples were obtained by means of IR.Theirspectrahavevisible differences in the 1 200～950 and 700～400 cm-1 range. Peak 1 174 cm-1 appears only in samples from Wenfeng, and from 700 to 400 cm-1, 5 peaks show in samples from Wenfeng while 7 peaks emerge from the other two sites. Turquoises in Erlitou site have similar spectra to those from Qingu and Yungaisi, and are more similar to Yungaisi of peak around 1 159 cm-1. According to A=lg(1/T), intensity of transmittance spectra were calculated and then Ratios(A783 cm-1/A837 cm-1) were yielded. The ratios of samplesfrom Qingu, Wenfeng, Yungaisi and Erlitou site are 0.819～0.920, 0.870～1.010, 0.806～0.860 and 0.827～0.878 respectively, allowing for a suggestion that turquoise in Erlitou site was the most probable from Yungaisi. This research can be used as example for identifying origin of the unearthed turquoise relics, which is more likely a good tool for archeological research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2767 (2015)
Detection of Cinnabars in Mongolian Medicines Using Raman Spectroscopy
HAN Siqingaowa, HASI Wuliji, LIN Xiang, LIN Shuang, YANG Fang, LOU Xiu-tao, and L Zhi-wei
Cinnabar could soothe the nerves and the powder of cinnabar is always added in traditional Chinese medicine or mongolian medicines. The surface-enhanced Raman spectrum of cinnabar was identified using a portable Raman spectrometer and most structure vibration information was obtained. The results show that the Raman peCinnabar could soothe the nerves and the powder of cinnabar is always added in traditional Chinese medicine or mongolian medicines. The surface-enhanced Raman spectrum of cinnabar was identified using a portable Raman spectrometer and most structure vibration information was obtained. The results show that the Raman peaks of cinnabars were located at 253, 290, 343 cm-1 and this three Raman characteristic peaks were selected for cinnabar identification. Meanwhile, the Raman spectra of several mongolian medicines were collected. The results showed that Raman signal of cinnabar could be observed in several mongolian medicines which contain cinnabar and Raman signal of cinnabar couldn’t be detected in several mongolian medicines without cinnabar. In addition, the cinnabar in the oral ulcer powder was semi-quantitative analyzed and the limit of detection could reach to 10% of mass fraction. The relationship between the doped amount of cinnabar in the oral ulcer powder and the Raman intensity of characteristic peak was fitted and the correlation coefficient (r) was 0.995 9, which validated the accuracy of the result. This Raman analysis method for cinnabar detection is rapid, simple and accurate and it can be applied widely in mongolian medicines determination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2773 (2015)
Red Blood Cells Raman Spectroscopy Comparison of Type Two Diabetes Patients and Rats
WANG Lei, LIU Gui-dong, MU Xin, XIAO Hong-bin, QI Chao, ZHANG Si-qi, NIU Wen-ying, JIANG Guang-kun, FENG Yue-nan, and BIAN Jing-qi
By using confocal Raman spectroscopy, Raman spectra were measured in normal rat red blood cells, normal human red blood cells, STZ induced diabetetic rats red blood cells, Alloxan induced diabetetic rats red blood cells and human type 2 diabetes red blood cells. Then principal component analysis (PCA) with support vectBy using confocal Raman spectroscopy, Raman spectra were measured in normal rat red blood cells, normal human red blood cells, STZ induced diabetetic rats red blood cells, Alloxan induced diabetetic rats red blood cells and human type 2 diabetes red blood cells. Then principal component analysis (PCA) with support vector machine (SVM) classifier was used for data analysis, and then the distance between classes was used to judge the degree of close to two kinds of rat model with type 2 diabetes. The results found significant differences in the Raman spectra of red blood cell in diabetic and normal red blood cells. To diabetic red blood cells, the peak in the amide ⅥCO deformation vibration band is obvious, and amide ⅤN—H deformation vibration band spectral lines appear deviation. Belong to phospholipid fatty acyl C—C skeleton, the 1 130 cm-1 spectral line is enhanced and the 1 088 cm-1 spectral line is abated, which show diabetes red cell membrane permeability increased. Raman spectra of PCA combined with SVM can well separate 5 types of red blood cells. Classifier test results show that the classification accuracy is up to 100%. Through the class distance between the two induced method and human type 2 diabetes, it is found that STZ induced model is more close to human type 2 diabetes. In conclusion, Raman spectroscopy can be used for diagnosis of diabetes and rats STZ induced diabetes method is closer to human type 2 diabetes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2776 (2015)
Simulated Experimental Research on Using Canopy Spectra of Surface Vegetation to Detect CO2 Microseepage Spots
JIANG Jin-bao, HE Ru-yan, Michael D Steven, and HU Qing-yang
With the global warming, people now pay more attention to the problem of the emission of greenhouse gas (CO2). Carbon capture and storage (CCS) technology is an effective measures to reduce CO2 emission. But there is a possible risk that the CO2 might leak from underground. However, there need to research and develop aWith the global warming, people now pay more attention to the problem of the emission of greenhouse gas (CO2). Carbon capture and storage (CCS) technology is an effective measures to reduce CO2 emission. But there is a possible risk that the CO2 might leak from underground. However, there need to research and develop a technique to quickly monitor CO2 leaking spots above sequestration fields. The field experiment was performed in the Sutton Bonington campus of University of Nottingham(52.8N, 1.2W) from May to September in 2008. The experiment totally laid out 16 plots, grass(cv Long Ley) and beans(Vicia faba cv Clipper) were planted in eight plots, respectively. However, only four grass and bean plots were stressed by the CO2 leakage, and CO2 was always injected into the soil at a rate of 1 L·min-1. The canopy spectra were measured using ASD instrument, and the grass was totally collected 6 times data and bean was totally collected 3 times data. This paper study the canopy spectral characteristics of grass and beans under the stress of CO2 microseepages through the field simulated experiment, and build the model to detect CO2 microseepage spots by using hyperspectral remote sensing. The results showed that the canopy spectral reflectance of grass and beans under the CO2 leakage stress increased in 580～680 nm with the stressed severity elevating, moreover, the spectral features of grass and beans had same rule during the whole experimental period. According to the canopy spectral features of two plants, a new index AREA(580～680 nm) was designed to detect the stressed vegetations. The index was tested through J-M distance, and the result suggested that the index was able to identify the center area and the core area grass under CO2 leakage stress, however, the index had a poor capability to discriminate the edge area grass from control. Then, the index had reliable and steady ability to identify beans under CO2 leakage stress. This result could provide theoretical basis and methods for detecting CO2 leakage spots using hyperspectral remote sensing in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2781 (2015)
Measurements of CO2 Concentration Profile in Troposphere Based on Balloon-Borne TDLAS System
YAO Lu, LIU Wen-qing, LIU Jian-guo*, KAN Rui-feng, XU Zhen-yu, RUAN Jun, and YUAN Song
The main source and sink of CO2 in the atmosphere are concentrated in the troposphere. It is of great significance to the study of CO2 flux and global climate change to obtain the accurate tropospheric CO2 concentration profile. For the characteristics of high resolution, high sensitivity and fast response of tunable dThe main source and sink of CO2 in the atmosphere are concentrated in the troposphere. It is of great significance to the study of CO2 flux and global climate change to obtain the accurate tropospheric CO2 concentration profile. For the characteristics of high resolution, high sensitivity and fast response of tunable diode laser absorption spectroscopy (TDLAS), a compact balloon-borne system based on direct absorption was developed to detect the CO2 concentration profiles by use of the 2 004.02 nm, R(16), ν1+ν3 line without the interfere of H2O absorption and the CO2 density of the number of molecules below 10 km in the troposphere was obtained. Due to the balloon-borne environment, a compact design of one single board integrated with laser driver, signal conditioning, spectra acquiring and concentration retrieving was developed. Limited by the working capability and hardware resources of embedded micro-processor, the spectra processing algorithm was optimized to reduce the time-cost. Compared with the traditional TDLAS sensors with WMS technique, this system was designed based on the direct absorption technique by means of an open-path Herriott cell with 20 m optical-path, which avoided the process of standardization and enhanced the environmental adaptation. The universal design of hardware and software platform achieved diverse gas measuring by changing the laser and adjusting some key parameters in algorithm. The concept of compact design helped to reduce the system’s power and volume and balanced the response speed and measure precision. The power consumes below 1.5 W in room temperature and the volume of the single board is 120 mm×100 mm×25 mm, and the measurement accuracy is ±0.6×10-6 at 1.5 s response time. It has been proved that the system can realize high precision detection of CO2 profile at 15 m vertical resolution in troposphere and TDLAS is an available method for balloon-borne detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2787 (2015)
Measurement of Trace C2H6 Based on Optical-Feedback Cavity-Enhanced Absorption Spectroscopy
WAN Fu, CHEN Wei-gen, GU Zhao-liang, ZOU Jing-xin, DU Ling-ling, QI Wei, and ZHOU Qu
Ethane is one of major fault characteristic gases dissolved in power transformer, the detection of Ethane with high accuracy and sensitivity is the key of dissolved gas analysis. In this paper, based on optical feedback theory and cavity-enhanced absorption spectroscopy, combined with quantum cascade laser, a detectionEthane is one of major fault characteristic gases dissolved in power transformer, the detection of Ethane with high accuracy and sensitivity is the key of dissolved gas analysis. In this paper, based on optical feedback theory and cavity-enhanced absorption spectroscopy, combined with quantum cascade laser, a detection system for dissolved gas C2H6 in transformer oil was built up. Based on the symmetry of the individual cavity modes, the phase matching of returning light in resonance with the cavity was achieved through LabVIEW codes. The optical feedback effect that the emitted light return to the laser cavity after a small delay time and lock to the resonance frequency of cavity, even and odd modes effect that the higher modes and lower modes structure will build up alternatively, and threshold current lowering effect of about 1.2 mA were studied and achieved. By cavity ring-down spectroscopy, the effective reflectivity of 99.978% and cavity finesse of 7 138.4 is obtained respectively. The frequency selectivity is 0.005 2 cm-1. With an acquisition time of 1s, this optical system allows detection for the PQ3 band of C2H6 with high accuracy of 95.72%±0.17% and detection limit of (1.97±0.06)×10-3 μL·L-1 at atmospheric pressure and temperature of 20 ℃, which lays a foundation for fault diagnose from dissolved gas analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2792 (2015)
Monitoring the Redox States of Thioredoxin in Protein-Protein Interaction Using Intrinsic Fluorescence Probe
WANG Pan, GUO Ai-yu, CHANG Guan-xiao, RAN Xia, ZHANG Yu, and GUO Li-jun
The cellular redox states directly affect cell proliferation, differentiation and apoptosis, and the redox states changes is particularly important to the regulation of cell survival or death. Thioredoxin is a kind of oxidation regulatory protein which is widely exists in organisms, and the change of redox states is alThe cellular redox states directly affect cell proliferation, differentiation and apoptosis, and the redox states changes is particularly important to the regulation of cell survival or death. Thioredoxin is a kind of oxidation regulatory protein which is widely exists in organisms, and the change of redox states is also an important process in redox regulation. In this work, we have used the site-directed mutagenesis of protein, SDS-polyacrylamide gel electrophoresis fluorescence spectroscopy and circular dichroism etc., to investigate redox states changes between TRX (E. coli) and glutathione peroxidase(GPX3) during their interaction. By observing the fluorescence spectra of TRX and its mutants, we have studied the protein interactions as well as the redox states switching between oxidation state TRX and the reduced state GPX3. The results demonstrate the presence of interactions and electron exchanges occurring between reduced GPX3 and oxidized TRX, which is of significance for revealing the physical and chemical mechanism of TRX in intracellular signal transduction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2797 (2015)
Analysis of Observers Metamerism Differences for Different Retinal Cone Visual Responses
HUANG Min, CUI Gui-hua, LIU Yu, and LIU Hao-xue
In order to investigate the cone’s spectral responses under different conditions for different aged observers with normal color vision, nine color patches with different hue angles distributed uniformly on the CIELAB color space were prepared, and the 27～35 observers were organized to carry out color matching experimenIn order to investigate the cone’s spectral responses under different conditions for different aged observers with normal color vision, nine color patches with different hue angles distributed uniformly on the CIELAB color space were prepared, and the 27～35 observers were organized to carry out color matching experiments on a monitor to match the nine printed color samples under four different viewing conditions including two illuminances, and two viewing fields. The spectral data obtained from the color matching experiments were compared with the spectral data of the nine target colors and used to test the performances of eleven color matching functions including CIE1931, CIE1964, CIE2006, Sarkar’s S1～S8 in terms of the percentage of the minimum CIEDE2000 value. For the four experiments, CIE2006 and S6 performed the best and with S1, S2 the worst. For different observers, the visual spectral responses’ of the retinal cone are different and the age has the obvious influence on the visual spectral responses. The observer metamerism is mainly caused by the different spectral response of the (λ) channel and for most observers the differences appeared at the responses of the peak wavelength, and the shift of the peak wavelength has no significant influence on the observers metamerism. The experimental results can provide evidences for the classification of the color matching functions for different observer categories and theoretical basis for the investigation of the observers metamerism..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2802 (2015)
Preparation of δ-Valerolactone and Its Spectral Analysis
FENG Shi-hong, JIA Tai-xuan, ZHANG Zhen-bin, GAO Jie, LIN Yan, and LIU Zi-li
In the study, CuO/ZnO/Al2O3 was prepared by sol-gel method. Its catalytic activity was evaluated by gas-phase catalytic dehydrogenation of 1,5-Pentanediol to δ-valerolactone as a probe reaction. CuO/ZnO/Al2O3 and long period reactive CuO/ZnO/Al2O3 were detected by XRD. Micro-structure and essence disciplinarian of CuO/In the study, CuO/ZnO/Al2O3 was prepared by sol-gel method. Its catalytic activity was evaluated by gas-phase catalytic dehydrogenation of 1,5-Pentanediol to δ-valerolactone as a probe reaction. CuO/ZnO/Al2O3 and long period reactive CuO/ZnO/Al2O3 were detected by XRD. Micro-structure and essence disciplinarian of CuO/ZnO/Al2O3 were disclosed. Metal ions had a cooperative effects during the catalytic dehydrogenation of 1,5-pentanediol to δ-valerolactone. After CuO/ZnO/Al2O3 deactivation, crystal particle size was increased clearly. It were found that characteristic diffraction peaks were caused by the catalyst temperature raising in methanol catalytic synthesis of ZnO. 1,5-Pentanediol and δ-valerolactone were detected by FTIR. Their internal chemical bond and molecular structure were disclosed. The purity of δ-valerolactone product was very high. δ-Valerolactone and its polymer were detected by DSC. δ-Valerolactone possessed with poor stability. Polymerization reaction was easily happened by itself. So it was worth focusing on how to improve the stability of the δ-valerolactone monomer. This study could provide basic data and experimental basis for gas-phase catalytic dehydrogenation of 1,5-Pentanediol to δ-valerolactone in pilot and industrial scale up research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2810 (2015)
Road Extraction in Remote Sensing Images Based on Spectral and Edge Analysis
ZHAO Wen-zhi, LUO Li-qun, GUO Zhou, YUE Jun, YU Xue-ying, LIU Hui, and WEI Jing
Roads are typically man-made objects in urban areas. Road extraction from high-resolution images has important applications for urban planning and transportation development. However, due to the confusion of spectral characteristic, it is difficult to distinguish roads from other objects by merely using traditional claRoads are typically man-made objects in urban areas. Road extraction from high-resolution images has important applications for urban planning and transportation development. However, due to the confusion of spectral characteristic, it is difficult to distinguish roads from other objects by merely using traditional classification methods that mainly depend on spectral information. Edge is an important feature for the identification of linear objects (e. g., roads). The distribution patterns of edges vary greatly among different objects. It is crucial to merge edge statistical information into spectral ones. In this study, a new method that combines spectral information and edge statistical features has been proposed. First, edge detection is conducted by using self-adaptive mean-shift algorithm on the panchromatic band, which can greatly reduce pseudo-edges and noise effects. Then, edge statistical features are obtained from the edge statistical model, which measures the length and angle distribution of edges. Finally, by integrating the spectral and edge statistical features, SVM algorithm is used to classify the image and roads are ultimately extracted. A series of experiments are conducted and the results show that the overall accuracy of proposed method is 93% comparing with only 78% overall accuracy of the traditional. The results demonstrate that the proposed method is efficient and valuable for road extraction, especially on high-resolution images..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2814 (2015)
Research on the Spectrophotometry for Determination of Flavonoids in Waste Residue of Stevia Rebaudiana
LUO Xu-yan, FANG Hao-bin*, HUANG Rui-yu, ZHAO Dong-fang, ZHU Ting, GUO Yang-yang, ZENG Yi-ping, LIU Ren-yue, and ZHU Dong
A spectrophotometric method for the determination of flavonoids content in Waste Residue of Stevia Rebaudiana was established by comparing the UV-Vis spectra with three spectrophotometric methods: Direct, AlCl3 and NaNO2-Al(NO3)3-NaOH method. The effects of spectrophotometric reaction were studied by analyzing the waveA spectrophotometric method for the determination of flavonoids content in Waste Residue of Stevia Rebaudiana was established by comparing the UV-Vis spectra with three spectrophotometric methods: Direct, AlCl3 and NaNO2-Al(NO3)3-NaOH method. The effects of spectrophotometric reaction were studied by analyzing the wavelength, the dosage of color development reagent, reaction time, temperature and pH. The further research was studied by analyzing linearity between the absorbance and the concentration, the stability of this color system, the recovery rate and so on. The results showed that NaNO2-Al(NO3)3-NaOH method was best. The wavelength was 500 nm. The standard sample was rutin. There was a good linear relationship in the ranges of 2～24 μg·mL-1, correlation coefficient R2=0.999 5. The recovery of the additional sample was 96.0%～104.3%. The relative standard deviation(RSD) is respectively 3.75%. The dosages of NaNO2 and Al(NO3)3 both were 1.0 mL, both of their reaction time was 6 min. The dosage of NaOH was 15.0 mL and the reaction time was 15 min. The temperature in the whole process of the reaction must be maintained at 40 ℃ and pH is 5. The spectrophotometric condition was further improved on the determination of flavonoids content. This method, which is simple, rapid and accuracy, can be used in practical application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2820 (2015)
Determination of Methyl Orange and Ethyl Orange in Two-Component Solution by Dual Wavelength Spectrophotometry
HU Yao-qiang, GAO Can, LIU Hai-ning, YE Xiu-shen, and WU Zhi-jian
The high similarity of MO and EO made it difficult to measure concentration of MOD and EOD. In this paper, dual wavelength spectrophotometry was used to determinate the concentration of MOD and EOD, which was proved to be fast and accrate. 429.00 nm and 469.50 nm were selected as deternination wavelengthes at pH 12. AnThe high similarity of MO and EO made it difficult to measure concentration of MOD and EOD. In this paper, dual wavelength spectrophotometry was used to determinate the concentration of MOD and EOD, which was proved to be fast and accrate. 429.00 nm and 469.50 nm were selected as deternination wavelengthes at pH 12. And the influences of Na+ and Cl- on determination of MOD and EOD were surveyed. The standard equations were A429=0.003 47+0.061 cM+0.056 46 cE and A469.50=0.002 8+0.074 37 cM+0.083 94 cE. Recovery of standard additions of MOD and EOD were larger than 95%, and relative standard deviation of standard equations were less than 2%. The addition of NaCl has little effect on recovery of standard additions and relative standard deviation of this method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2825 (2015)
The Study Based on Rectification of Vegetation Indices with Dust Impact
CHEN Fan-tao, ZHAO Wen-ji, and YAN Xing
Vegetation indicesarethe simplest and most effective metric parameters representing the features of vegetation cover and growth condition. This paper used Euonymus japonicas Thunb as a study case and collected 200 leaf samples in 20 locations. Using electronic analytical balance and ASD hyperspectral radiometer with WiVegetation indicesarethe simplest and most effective metric parameters representing the features of vegetation cover and growth condition. This paper used Euonymus japonicas Thunb as a study case and collected 200 leaf samples in 20 locations. Using electronic analytical balance and ASD hyperspectral radiometer with Win FOLIA leaf area meter obtainedthe data of the amount of dust, spectral information and leaf area. Through comparative analysis between dust and clean leaves, differences of spectral curve and vegetation indices were apparent. Then, combined with dust weight and spectral data, dust correction modelsfor vegetation indices were built. The analysis results showedthat the spectral curve between clean and dust leaves havetypical characteristics: blue edge and red edge were at 520 and 705 nm; however, dust influenced leaf reflectance significantly in range of 350～700, 750～1 350, 1 500～1 850, 1 900～2 100 nm wavelength, and had a greater impact on vegetation indices. With dust weight increasing, the linear correlation of dust with NDVI and PRI was non-significant, but that with NDWI, NDII and CAI was still significant. The verification of correction models showedthat coefficient of determination (R2) of NDVI, NDII, CAI and PRI were 0.547, 0.430, 0.653 and 0.96 and their root mean square error (RMSE) was 0.035, 0.020, 0.112 and 0.009 respectively. Furthermore, itshowed that applyingdust correction models can improve the accuracy of vegetation indices calculation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2830 (2015)
Plant Spectral Discrimination Based on Phenological Features
ZHANG Lei, ZHAO Jian-long, JIA Kun, and LI Xiao-song
Spectral analysis plays asignificant role onplant characteristic identification and mechanism recognition, there were many papers published on the aspects of absorption features in the spectra of chlorophyll andmoisture, spectral analysis onvegetation red edge effect, spectra profile feature extraction, spectra profileSpectral analysis plays asignificant role onplant characteristic identification and mechanism recognition, there were many papers published on the aspects of absorption features in the spectra of chlorophyll andmoisture, spectral analysis onvegetation red edge effect, spectra profile feature extraction, spectra profile conversion, vegetation leaf structure and chemical composition impacts on the spectra in past years. However, fewer researches issued onspectral changes caused by plant seasonal changes oflife form, chlorophyll, leaf area index. This paper studied on spectral observationof 11 plantsof various life form, plant leaf structure and its size, phenological characteristics, they includedeciduous forest with broadvertical leaf, needleleafevergreen forest, needleleafdeciduous forest, deciduous forest with broadflat leaf, high shrub with big leaf, high shrub with little leaf, deciduous forest with broad little leaf, short shrub, meadow, steppe andgrass. Field spectral data were observed with SVC-HR768 (Spectra Vista company, USA), the band width covers 350～2 500 nm, spectral resolution reaches 1~4 nm. The features of NDVI, spectral maximum absorption depth in green band, and spectral maximumabsorption depth in red bandwere measured after continuum removal processing, the mean, amplitude andgradientof thesefeatures onseasonalchange profilewere analyzed, meanwhile, separability research on plant spectral feature of growth period and maturation period were compared. The paper presents a calculation method ofseparabilityof vegetation spectra which consider feature spatial distances. This index is carried on analysis of the vegetation discrimination. The results show that: the spectral featuresduring plant growth periodare easier to distinguish than them during maturation period. With the same features comparison, plant separabilityof growth period is 3 points higherthan it during maturation period. The overall separabilityof vegetation spectrumfeatures shows seasonal amplitude>seasonal gradient>seasonal mean during the growth period, but the separabilityof seasonal gradient shows highest value for the plant seasonal NDVI change. Therefore, the features of seasonal NDVI gradient, seasonal amplitude of maximumspectral absorption depth in green band, seasonal amplitude of maximumabsorption depthin red band are effective composition for plant discrimination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2836 (2015)
Spectral Uncertainty of Terrestrial Objects and the Applicability of Spectral Angle Mapper Algorithm
Cen Yi, Zhang Genzhong, Zhang Lifu, Lu Xuhui, and Zhang Feizhou
The spectral uncertainty of terrestrial objects causes a certain degree of spectral differences among feature spectra, which affects the accuracy of object recognition and also impacts the object recognition of spectral angle mapper algorithm (SAM). The spectral angle mapper algorithm is based on the overall similarityThe spectral uncertainty of terrestrial objects causes a certain degree of spectral differences among feature spectra, which affects the accuracy of object recognition and also impacts the object recognition of spectral angle mapper algorithm (SAM). The spectral angle mapper algorithm is based on the overall similarity of the spectral curves, which was widely used in the classification of hyperspectral remotely sensed information. The spectral angle mapper algorithm does not take the spectral uncertainty of terrestrial objects into account while calculating the spectral angle between the spectral curves, and therefore does not tend to correctly identify the target objects. The applicability of the spectral angle mapper algorithm is studied for the spectral uncertainty of terrestrial objects and a modified SAM is proposed in this paper．In order to overcome the influence of the spectral uncertainty, the basic idea is to set a spectral difference value for the test spectra and the reference spectra and to calculate the spectral difference value based on derivation method according to the principle of minimum angle between the test spectra and the reference spectra. By considering the impact of the spectral uncertainty of terrestrial objects, this paper uses five kaolinite mineral spectra of USGS to calculate the spectral angle between the five kalinite mineral spectra by using local band combination and all bands to verify the improved algorithm. The calculation results and the applicability of the spectral angle mapper algorithm were analyzed. The results obtained from the experiments based on USGS mineral spectral data indicate that the modified SAM is not only helpful in characterizing and overcoming the impact of the spectral uncertainty but it can also improve the accuracy of object recognition to certain extent especially for selecting local band combination and has better applicability for the spectral uncertainty of terrestrial objects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2841 (2015)
A Hyperspectral Imagery Anomaly Detection Algorithm Based on Gauss-Markov Model
GAO Kun, LIU Ying, WANG Li-jing, ZHU Zhen-yu, and CHENG Hao-bo
With the development of spectral imaging technology, hyperspectral anomaly detection is getting more and more widely used in remote sensing imagery processing. The traditional RX anomaly detection algorithm neglects spatial correlation of images. Besides, it doesnot validly reduce the data dimension, which costs too muWith the development of spectral imaging technology, hyperspectral anomaly detection is getting more and more widely used in remote sensing imagery processing. The traditional RX anomaly detection algorithm neglects spatial correlation of images. Besides, it doesnot validly reduce the data dimension, which costs too much processing time and shows low validity on hyperspectral data. The hyperspectral images follow Gauss-Markov Random Field (GMRF) in space and spectral dimensions. The inverse matrix of covariance matrix is able to be directly calculated by building the Gauss-Markov parameters, which avoids the huge calculation of hyperspectral data. This paper proposes an improved RX anomaly detection algorithm based on three-dimensional GMRF. The hyperspectral imagery data is simulated with GMRF model, and the GMRF parameters are estimated with the Approximated Maximum Likelihood method. The detection operator is constructed with GMRF estimation parameters. The detecting pixel is considered as the centre in a local optimization window, which calls GMRF detecting window. The abnormal degree is calculated with mean vector and covariance inverse matrix, and the mean vector and covariance inverse matrix are calculated within the window. The image is detected pixel by pixel with the moving of GMRF window. The traditional RX detection algorithm, the regional hypothesis detection algorithm based on GMRF and the algorithm proposed in this paper are simulated with AVIRIS hyperspectral data. Simulation results show that the proposed anomaly detection method is able to improve the detection efficiency and reduce false alarm rate. We get the operation time statistics of the three algorithms in the same computer environment. The results show that the proposed algorithm improves the operation time by 45.2%, which shows good computing efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2846 (2015)
Hyperspectral Remote Sensing Estimation Models for Pasture Quality
MA Wei-wei, GONG Cai-lan, HU Yong, WEI Yong-lin, LI Long, LIU Feng-yi, and MENG Peng
Crude protein (CP), crude fat (CFA) and crude fiber (CFI) are key indicators for evaluation of the quality and feeding value of pasture. Hence, identification of these biological contents is an essential practice for animal husbandry. As current approaches to pasture quality estimation are time-consuming and costly, anCrude protein (CP), crude fat (CFA) and crude fiber (CFI) are key indicators for evaluation of the quality and feeding value of pasture. Hence, identification of these biological contents is an essential practice for animal husbandry. As current approaches to pasture quality estimation are time-consuming and costly, and even generate hazardous waste, a real-time and non-destructive method is therefore developed in this study using pasture canopy hyperspectral data. A field campaign was carried out in August 2013 around Qinghai Lake in order to obtain field spectral properties of 19 types of natural pasture using the ASD Field Spec 3, a field spectrometer that works in the optical region (350～2 500 nm) of the electromagnetic spectrum. In additional to the spectral data, pasture samples were also collected from the field and examined in laboratory to measure the relative concentration of CP (%), CFA (%) and CFI (%). After spectral denoising and smoothing, the relationship of pasture quality parameters with the reflectance spectrum, the first derivatives of reflectance (FDR), band ratio and the wavelet coefficients (WCs) was analyzed respectively. The concentration of CP, CFA and CFI of pasture was found closely correlated with FDR with wavebands centered at 424, 1 668, and 918 nm as well as with the low-scale (scale=2, 4) Morlet, Coiflets and Gassian WCs. Accordingly, the linear, exponential, and polynomial equations between each pasture variable and FDR or WCs were developed. Validation of the developed equations indicated that the polynomial model with an independent variable of Coiflets WCs (scale=4, wavelength=1 209 nm), the polynomial model with an independent variable of FDR, and the exponential model with an independent variable of FDR were the optimal model for prediction of concentration of CP, CFA and CFI of pasture, respectively. The R2 of the pasture quality estimation models was between 0.646 and 0.762 at the 0.01 significance level. Results suggest that the first derivatives or the wavelet coefficients of hyperspectral reflectance in visible and near-infrared regions can be used for pasture quality estimation, and that it will provide a basis for real-time prediction of pasture quality using remote sensing techniques..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2851 (2015)
Study on the Relationship between Hyperspectral Polarized Information of Soil Salinization and Soil Line
XU Wen-ru, HAN Yang*, QIN Yan, and JIN Lun
It has important significance to assess soil salinization correctly for agricultural production and ecological environment. Soil line can indicate soil salinization in a certain extent. But the soil spectral characteristics obtained at different angles will change with the changing of the soil line parameters. Base on It has important significance to assess soil salinization correctly for agricultural production and ecological environment. Soil line can indicate soil salinization in a certain extent. But the soil spectral characteristics obtained at different angles will change with the changing of the soil line parameters. Base on polarized hyper-spectral reflectivity obtained in the laboratory, the study analyzes the relationship between the soil salinization and soil line parameters, explores preliminarily the best way to obtain soil line. The results show: (1) Soil spectral reflectance gradually increased slowly with increasing band. With the enhanced level of salinization, soil spectral reflectance of the first to be gradually reduced to a critical value and then gradually increased. (2) Soil salinization has a linear correlation with the soil slope and intercept. With the enhanced level of salinization, soil slope becomes smaller, and intercept becomes larger. (3) Viewing zenith angle affects the relationship between the polarization state and soil line parameters. When viewing zenith angle is fixed, there is a regularity between the polarization state and soil line parameters. When the viewing zenith angle is between 0°～50°, with the angle becoming larger, soil slope becomes larger, and intercept becomes smaller. (4) Polarization states affects degree of correlation between soil salinization and soil line parameters. When polarization angle is 90° and viewing zenith angle is 25°, the relationship model between soil salinization and soil line parameters is better. The research results can be used to evaluate the degree of salinization soil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2856 (2015)
Method of Remote Sensing Identification for Mineral Types Based on Multiple Spectral Characteristic Parameters Matching
WEI Jing, MING Yan-fang, HAN Liu-sheng, REN Zhong-liang, and GUO Ya-min
The traditional mineral mapping methods with remote sensing data, based on spectral reflectance matching techniques, shows low accuracy, for obviously being affected by the image quality, atmospheric and other factors. A new mineral mapping method based on multiple types of spectral characteristic parameters is presentThe traditional mineral mapping methods with remote sensing data, based on spectral reflectance matching techniques, shows low accuracy, for obviously being affected by the image quality, atmospheric and other factors. A new mineral mapping method based on multiple types of spectral characteristic parameters is presented in this paper. Various spectral characteristic parameters are used together to enhanced the stability in the situation of atmosphere and environment background affecting. AVIRIS (Airborne Visible Infrared Imaging Spectrometer) data of Nevada Cuprite are selected to determine the mineral types with this method. Typical mineral spectral data are also obtained from USGS (United States Geological Survey) spectral library to calculate the spectral characteristic parameters. A mineral identification model based on multiple spectral characteristic parameters is built by analyzing the various characteristic parameters, and is applied in the mineral mapping experiment in Cuprite area. The mineral mapping result produced by Clark et al. in 1995 is used to evaluate the effect of this method, results show, that mineral mapping results with this method can obtain a high precision, the overall mineral identification accuracy is 78.96%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2862 (2015)
Determination the Change of Main Trace Elements in the Ovary with Self- and Cross-Pollination of Chinese Chestnut by ICP-MS
ZOU Feng, GUO Su-juan*, WANG Jing, PENG Jing-jing, ZHANG Xiao-na, and PENG Ya-qin
Castanea mollissima Blume has potential as an non-wood forest trees that have been cultivated for thousands of years in China. In order to elucidate the trace elements of chestnut ovary, the major trace elements of self- and cross-pollination chestnut ovary were determined by inductively coupled plasma mass spectrometrCastanea mollissima Blume has potential as an non-wood forest trees that have been cultivated for thousands of years in China. In order to elucidate the trace elements of chestnut ovary, the major trace elements of self- and cross-pollination chestnut ovary were determined by inductively coupled plasma mass spectrometry. The results showed that self- and cross-pollination 5～50 d, six trace elements trends showed fluctuations. After cross-pollination 20 d, the content of Ca was up to 6.50 mg·g-1, while the self-pollination 10 d, the content of Ca reached up to 7.77 mg·g-1. After cross- and self-pollination pollination 30 d, the content of Mg were highest, 4.19 and 4.69 mg·g-1, respectively. After cross-pollination 5 d, the content of Zn reached the highest, 0.038 7 mg·g-1, while self-pollination 10d the content of Zn was 0.039 9 mg·g-1. After self- and cross-pollination 35 d, the content of Fe were 0.022, 0.019 mg·g-1, respectively. After cross- and self-pollination 20 d, the content of Cu were 0.056, 0.045 mg·g-1, respectively. After self-pollination 40d, the content of Mn reaching the highest was 1.204 mg·g-1, while cross-pollination 30 d, the content of Mn reached its maximum 0.845 mg·g-1. The results can provide a reference for spraying fertilizer on the ovary development, thereby improving chestnut production..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2867 (2015)
Research on the Content Characteristics and Pollution Evaluation of Heavy Metals in Filtered Water and Suspended Particles from Gansu, Ningxia and Inner Mongolia Sections of the Yellow River in Wet Season Using HR-ICP-MS
MA Xiao-ling, LIU Jing-jun, DENG Feng-yu, ZUO Hang, HUANG Fang, ZHANG Li-yang, and LIU Ying
The content characteristics, pollution evaluation and source identification of 6 heavy Metals (Cd, Pb, Cr, As, Cu and Zn) in filtered water and 9 heavy Metals (Cd, Pb, Cr, Ni, Cu, V, Co, Zn and Mn) in suspended particles from 10 sampling sites such as Zhaojunfuqiao (S1) and Baotoufuqiao (S2), etc. from Gansu, Ningxia aThe content characteristics, pollution evaluation and source identification of 6 heavy Metals (Cd, Pb, Cr, As, Cu and Zn) in filtered water and 9 heavy Metals (Cd, Pb, Cr, Ni, Cu, V, Co, Zn and Mn) in suspended particles from 10 sampling sites such as Zhaojunfuqiao (S1) and Baotoufuqiao (S2), etc. from Gansu, Ningxia and Inner Mongolia sections of the Yellow River in 2012 Wet Season were studied to understand the condition of the heavy metal pollution in Gansu, Ningxia and Inner Mongolia Sections of the Yellow River by using high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS). Multivariate geochemical approaches and statistical analysis were also exploited for assessing the level of heavy metals in filtered water and suspended particles from studied area. The results showed that in filtering water, only the concentrations of Cr exceeded the standard value of Environmental Quality Standard for Surface Water (GB3838—2002) and were the highest (74.8～94.7 μg·L-1) among all elements in 10 sampling sites; Single factor pollution index (Ii) results suggested that the water quality in all sampling sites were contaminated by both Cr and total nitrogen (TN), with the exception of TN in Baotoufuqiao (S2); Integrated Nemerow pollution index (I) indicated that the I values in all sampling sites were between 1～2 (light pollution), which implied that the water quality in Gansu, Ningxia and Inner Mongolia sections, especially downstream sections (S1～S6) of the Yellow River wasn’t an ideal source for drinking and using in aquaculture any more. In suspended particles, concentrations of heavy metals were relatively higher than their soil background values in 10 sampling sites, except Ni in S10 (34.7 μg·L-1). Index of geo-accumulation (Igeo) indicated that the Igeo values of Pb, Cr, Ni, Cu, V, Co, Zn and Mn in all sampling sites were less than 1 (unpolluted or unpolluted-moderately polluted), respectively, while ICdgeo were the highest in 10 sampling sites among all heavy metals and with the moderately to strong contamination in Zhaojunfuqiao (S1), Baotoufuqiao (S2), Wuhai (S5) and Dongdagouruhuanghekou (S8). The results of this paper would help to supply reliable experimental data for researching of distribution, migration and effective protection of heavy metals in study area..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2872 (2015)
Direct Determination of Heavy Metal Elements in Propolis by Inductively Coupled Plasma Mass Spectrometry
ZHANG Ping, FU Liang, and XIE Hua-lin
In current study, a method was established for simultaneous quantitative analysis of Cr, Ni, As, Cd, Sb, Sn, Hg and Pb in propolis by using inductively coupled plasma mass spectrometry. Before analyzed by ICP-MS, the propolis was diluted with n-propanol/xylene(70∶30, φ). Organic sample can remain stable by diluting witIn current study, a method was established for simultaneous quantitative analysis of Cr, Ni, As, Cd, Sb, Sn, Hg and Pb in propolis by using inductively coupled plasma mass spectrometry. Before analyzed by ICP-MS, the propolis was diluted with n-propanol/xylene(70∶30, φ). Organic sample can remain stable by diluting with n-propanol/xylene, result from long-time sample dispersion in the solution. Carbon accumulation on the sampling cone, which comes from the high carbon content of butter, will clog the orifice and decrease analysis sensitivity. Thus a small amount of oxygen was added into the argon gas line to eliminate carbon. ORS was used to eliminate the polyatomic interferences caused by the high salty matrixes. The effects of the He collision gas flow rate on estimating detection limits of Cr, Ni and As were investigated. The matrix effects and the instrument drift have been calibrated with Rh as internal standard element. The results show that the detection limits is in the range of 20.8～102.7 ng·L-1, the recovery is in the range of 92.0%～109.0%, and the RSD is less than 3.5%. This method was simple, sensitive and precise to simultaneously analyze 8 heavy metal elements in propolis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2878 (2015)
Analysis of Trace Inorganic Elements in Castor Oil by Inductively Coupled Plasma Mass Spectrometry
LI Tan-ping, XIE Hua-lin, and NIE Xi-du
A method for the determination of Na, Mg, Si, P, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Hg and Pb in castor oil after direct dilution with ethanol by inductively coupled plasma mass spectrometry (ICP-MS) was established. The sample was diluted by ethanol before ICP-MS determination. The condensation andA method for the determination of Na, Mg, Si, P, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Hg and Pb in castor oil after direct dilution with ethanol by inductively coupled plasma mass spectrometry (ICP-MS) was established. The sample was diluted by ethanol before ICP-MS determination. The condensation and deposition of high concentrations of carbon in mass cone interface and ion lens, which will decrease the sensitivity of element analysis, were avoided effectively by introducing O2 to plasma. The mass spectral interferences were eliminated by octopole reaction system (ORS). The matrix effects were calibrated to using Sc, Ge, Rh and Ir as internal standard elements. Au standard solution, which could form amalgam alloy with Hg, was dropped to eliminate the memory effect of Hg. The results show that the correlation coefficient for analyte is no less than 0.999 5, the detection limits is in the range of 0.06～20.1 ng·L-1, the recovery is in the range of 990.4%～110.2%, and the RSD is less than 4.8%. This method was very fast, simple and accurate to simultaneously analyze multi-elements in castor oil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2882 (2015)
Pretreatment of Aluminum-Lithium Alloy Sample and Determination of Argentum and Lithium by Spectral Analysis
ZHOU Hui, TAN Qian, GAO Ya-ling, SANG Shi-hua, and CHEN Wen
Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Flame Atomic Absorption Spectrometry (FAAS) and Visible Spectrometry (VS) was applied for determination of Ag and Li in lithium-aluminium alloy standard sample and test sample, their respective advantages and disadvantages were compared, the excellent Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Flame Atomic Absorption Spectrometry (FAAS) and Visible Spectrometry (VS) was applied for determination of Ag and Li in lithium-aluminium alloy standard sample and test sample, their respective advantages and disadvantages were compared, the excellent selectivity of ICP-OES was confirmed by analyses of certified standard sample. Three different sample digestion methods were compared and discussed in this study. It was found that the better accuracy would be obtained by digesting sample with chloroazotic acid while the content of Li was measured by FAAS, and it was better to digest sample with hydrochloric acid and hydrogen peroxide while determining Ag and Li by ICP-OES simultaneously and determining Ag by FAAS and VS. The interference of co-existing elements and elimination methods was detailedly discussed. Ammonium hydroxide was added to adjust the sample solution into alkalescent and Al, Ti, Zr was precipitated by forming hydroxide precipitation, Mg and Cu was formed complex precipitation with 8-hydroxyquinoline in this condition, then the interference from matrix element to determinate Ag by FAAS was eliminated. In addition, phosphate was used to precipitate Ti to eliminate its interference for determination of Li by FAAS. The same treatment of determination for Ag by FAAS was used to eliminate the interference of matrix element for determination of Ag by VS, the excess of nitrate was added into sample and heated to release Ag+ from silver chloride complex, and the color of 8-hydroxyquinoline was eliminated because of decomposed by heating. The accuracy of analysis result for standard sample was conspicuously improved which confirms the efficient of the method to eliminate interference in this study. The optimal digestion method and eliminate interference method was applied to lithium-aluminium alloy samples. The recovery of samples was from 100.39% to 103.01% by ICP-OES determination for Ag, and from 100.42% to 103.01% by ICP-OES determination for Li. The recovery ranged from 95.91% to 99.98% by FAAS determination for Ag, and ranged from 98.04% to 99.98% for FAAS determination of Li. The recovery was from 98.00% to 101.00 by VS determination for Ag, the analysis results all meet the analysis requirement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2886 (2015)
Analyse Output Specurum in Miniature Transmission X-Ray Tube of Aluminum Window and Silver Target by MC Simulation
WANG Lei, ZHANG Qing-xian, GE Liang-quan, LU Zhen-rui, LUO Yao-yao, ZHAO Jian-kun, and CHEN Shuang
The miniature transmission X-ray tube is widely used in energy dispersive X-ray Fluorescence Analysis (EDXRFA). The miniature transmission X-ray tube with a small, low power consumption, X-ray emission efficiency that can be made the excitation source of handheld X-ray energy dispersive fluorescence analyzer. BerylliumThe miniature transmission X-ray tube is widely used in energy dispersive X-ray Fluorescence Analysis (EDXRFA). The miniature transmission X-ray tube with a small, low power consumption, X-ray emission efficiency that can be made the excitation source of handheld X-ray energy dispersive fluorescence analyzer. Beryllium (Be) is the most commonly used X-ray window material. But beryllium is expensive and toxic. At the same time set filtering window by aluminum (Al) to reducing low-energy scattering rays. This paper be adopted Al for exit window material of miniature transmission X-ray tube, achieve high-energy rays transmission and low-energy scattered radiation shielding, at the same time reduce production cost and difficulty. The present paper simulate the X-ray tube output spectrum of silver (Ag) target and aluminum window with different thickness by MCNP5. We consider the X-ray of low energy part is completely shielded when aluminum windows thickness is greater than 1.5 mm. We can conclude that 2 μm and 0.8 mm are the best combination of target thickness and aluminum windows through comparative analysis of existing research results. Then we can get flux of high energy part is big and low energy part is small when the target is 2 μm thick Ag and the window is 0.8 mm thick Al..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2891 (2015)
Analysis of the Decorated Silicate Beads Excavated from Tomb M4 of the Ma-Jia-Yuan Warring States Cemetery, Gansu Province
HUANG Xiao-juan, YAN Jing, and WANG Hui
This paper reports the analysis results of 11 decorated silicate beads samples excavated from Ma Jia-yuan Warring State Cemetery, Gan Su Province with the portable X-ray fluorescence spectrometer, laser Raman spectrometer and X-ray diffraction spectrometer. It is includes 3 types among these samples on the basis of theThis paper reports the analysis results of 11 decorated silicate beads samples excavated from Ma Jia-yuan Warring State Cemetery, Gan Su Province with the portable X-ray fluorescence spectrometer, laser Raman spectrometer and X-ray diffraction spectrometer. It is includes 3 types among these samples on the basis of their chemical composition, NaO-CaO-SiO2, PbO-BaO-SiO2 glass system, and glassy faience. The blue part of the NaO-CaO-SiO2 glass sample was colored by Co2+, and Sb2O5 was discovered as opacifier. The results of Laser Raman analysis shows in some circle beads exits Chinese blue and Chinese purple. Combined with the existing research results the early cultural factors and technical exchange reflected from these samples are discussed. It shows that the material and craftsmanship of the beads contained Chinese blue and Chinese purple were affected by Qin Culture. But the composition of the Na-Ca-SiO2 glass eye bead is similar with those excavated from Xin Jiang area. It infers the technology of glass manufacture of the Xi Ron nationality was influenced by the Qin Culture and the grassland nationalities’ culture simultaneously. The faience bead composed with the inner core and the outer glassy layer is possible a kind of transitional type between the faience and the real glass. This information offers a new reference for the research of the origin of the glass technology in the ancient China..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2895 (2015)
Species Determination and Spectral Characteristics of Swelling Clay Minerals in the Pliocene Sandstones in Xinghai, Qinghai
WANG Chao-wen, CHEN Jiang-jun, FANG Qian, YIN Ke, and HONG Han-lie
X-ray diffraction (XRD) and Fourier infrared absorption spectroscopy (FTIR) were conducted to deepen our research on specific species and spectral characteristics of swelling clay minerals in the Pliocene sandstones in Xinghai, Qinghai province. XRD results show that swelling clay minerals are dominant clay minerals inX-ray diffraction (XRD) and Fourier infrared absorption spectroscopy (FTIR) were conducted to deepen our research on specific species and spectral characteristics of swelling clay minerals in the Pliocene sandstones in Xinghai, Qinghai province. XRD results show that swelling clay minerals are dominant clay minerals in the sandstones, which can be up to 97% in percentage. XRD patterns show 060 reflections of the samples occur both remarkably at 1.534 and 1.498 , indicating the samples contain physical mixtures of trioctahedral and dioctahedral swelling clay minerals, respectively. Further treatment of Li-300 ℃ heat and glycerol saturation shows the swelling clay minerals collapse to 9.3～9.9 with a partial expansion to ～18 . This indicates the swelling clay minerals dominate montmorillonite and contain minor saponite. The montmorillonite shows no swelling after Li-300 ℃ heat and glycerol saturation because of Li+ inserting into the octahedral layers, which balances the layer charge caused by the substitution of Mg to Al. FTIR results show the samples are composed of a kind of phyllosilicate with absorbed and structural water, which is in agreement with the results of XRD. Absorbed peaks at 913, 842, 880 cm-1, corresponding to OH associated with Al—Al, Al—Mg, and Al—Fe pairs, further indicates the minerals are dominant dioctahedron in structure. Meanwhile, absorbed peaks at 625 and 519 cm-1, corresponding to coupled Si—O and Al—O—Si deformation, indicates parts of Si is replaced by Al in tetrahedron. The spectral characteristics of the samples are against the presence of beidellite and nontronite based on the results of XRD and FTIR, while demonstrating an existence of montmorillonite. This study, to distinguish the specific species of swelling clay species in clay minerals, would be of great importance when using clay mineralogy to interpret provenance and climatic information..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2901 (2015)
Research on New Type of Spectral Modulation Polarization Measurement Technology
ZHAO Jia, ZHOU Feng, LI Huan, and ZHAO Hai-bo
Spectral Modulation Polarization Measurement technology (SMPM) is a new type of polarization modulation technology, with an achromatic /4 retarder, a multiple-order retarder and a polarizer the polarization information of incident light can be encoded into the spectral dimension, sinusoidal which amplitude scales with Spectral Modulation Polarization Measurement technology (SMPM) is a new type of polarization modulation technology, with an achromatic /4 retarder, a multiple-order retarder and a polarizer the polarization information of incident light can be encoded into the spectral dimension, sinusoidal which amplitude scales with the degree of the linear polarization and phase scales with the angle of the linear polarization can be acquired directly. With a dedicated algorithm for the modulated spectrum, we can get degree and angle of the linear polarization, spectral information and radiation information of the target. This paper expounds the basic principle of SMPM and concrete implementation scheme is proposed. Demodulation algorithm is designed before experimental platform are set up. Experiment which verified the correctness on the SMPM has carried on. The experimental results show the correctness and feasibility of SMPM. Compared with traditional polarization modulate techniques no moving parts and electronic components are including in this scheme. It’s also has the advantages of compact and low mass. We can get all the polarization information through one single measurement rather than get Stokes parameters for further calculations. This study provides a new kind of technological approaches for the development of new space polarization detecting sensor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2906 (2015)
A Time-Spatial Resolvable High Speed Spectrograph and Its Application on Spectrum Measurement of a Nanosecond Pulsed Underwater Spark Discharge
NIU Zhi-wen, YAN Xian-feng, LI Shu-han, WEN Xiao-qiong, and LIU Jin-yuan
Recently, the diagnosis of the characteristic of pulsed underwater electrical discharges plasma have received significant attention. The measurement of a time-spatial resolved spectrum emitted from a single discharge pulse is important for understanding the time-spatial evolution characteristics of plasma generated by Recently, the diagnosis of the characteristic of pulsed underwater electrical discharges plasma have received significant attention. The measurement of a time-spatial resolved spectrum emitted from a single discharge pulse is important for understanding the time-spatial evolution characteristics of plasma generated by a pulsed high-voltage discharge in water. In this paper, a high speed time-spatial resolvable spectrograph for measuring the emission spectrum of a single electrical discharge pulse was reported. The high speed time-spatial resolvable spectrograph has been constructed by combining an ultrahigh-speed frame camera system with monochromator. Software for the spectral analyzing was also developed. The performance of the spectrograph was tested by using a 632.8 nm He-Ne laser beam at a 1 200 g·mm-1 grating. The pixel resolution for 632.8 nm spectra is 0.013 nm. The instrument broadening for 632.8 nm spectra is (0.150 ± 0.009)nm when the exposure time of the camera is 20 ns and the width of entrance slit is 0.2 mm, and increases with increasing the slit width. The change of exposure time of the camera has no influence on the instrument broadening, ensuring the spectrograph in a steady performance while adjusting the exposure time of the camera. With the spectrograph, time-spatial resolved spectra emitted from a single discharge pulse of an underwater nanoseconds spark discharge were obtained. It provides good data for investigating the time-spatial evolution characteristics of the discharge plasma during a single discharge pulse. The spectrograph developed in this work provides a technical approach for studying the time-spatial evolution characteristic of plasma generated by a single electrical discharge pulse..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2911 (2015)
A Brillouin Scattering Spectrum Feature Extraction Based on Flies Optimization Algorithm with Adaptive Mutation and Generalized Regression Neural Network
ZHANG Yan-jun, LIU Wen-zhe, FU Xing-hu, and BI Wei-hong
According to the high precision extracting characteristics of scattering spectrum in Brillouin optical time domain reflection optical fiber sensing system, this paper proposes a new algorithm based on flies optimization algorithm with adaptive mutation and generalized regression neural network. The method takes advantaAccording to the high precision extracting characteristics of scattering spectrum in Brillouin optical time domain reflection optical fiber sensing system, this paper proposes a new algorithm based on flies optimization algorithm with adaptive mutation and generalized regression neural network. The method takes advantages of the generalized regression neural network which has the ability of the approximation ability, learning speed and generalization of the model. Moreover, by using the strong search ability of flies optimization algorithm with adaptive mutation, it can enhance the learning ability of the neural network. Thus the fitting degree of Brillouin scattering spectrum and the extraction accuracy of frequency shift is improved. Model of actual Brillouin spectrum are constructed by Gaussian white noise on theoretical spectrum, whose center frequency is 11.213 GHz and the linewidths are 40～50, 30～60 and 20～70 MHz, respectively. Comparing the algorithm with the Levenberg-Marquardt fitting method based on finite element analysis, hybrid algorithm particle swarm optimization, Levenberg-Marquardt and the least square method, the maximum frequency shift error of the new algorithm is 0.4 MHz, the fitting degree is 0.991 2 and the root mean square error is 0.024 1. The simulation results show that the proposed algorithm has good fitting degree and minimum absolute error. Therefore, the algorithm can be used on distributed optical fiber sensing system based on Brillouin optical time domain reflection, which can improve the fitting of Brillouin scattering spectrum and the precision of frequency shift extraction effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2916 (2015)
Identification of Metoprolol Tartrate Tablets from Different Manufacturers by Different Near Infrared Spectrometers
LI Qi-lu, WANG Fei, WANG Jin-feng, ZANG Heng-chang, ZHANG Hui, and JIANG Wei
To rapidly identify Metoprolol Tartrate tablets from different manufacturers, a qualitative analysis model can be established by near infrared spectroscopy. Firstly, AntarisII Fourier-transform near infrared (FT-NIR) spectroscopy and Micro NIR1700 Spectrometer were used to collect spectral data of 66 batches of samplesTo rapidly identify Metoprolol Tartrate tablets from different manufacturers, a qualitative analysis model can be established by near infrared spectroscopy. Firstly, AntarisII Fourier-transform near infrared (FT-NIR) spectroscopy and Micro NIR1700 Spectrometer were used to collect spectral data of 66 batches of samples which come from four different manufacturers, then 44 samples of calibration set and 22 samples of validation set were acquired by random sampling. In order to build up a PLS-DA model, the first derivative with Savitzky-Golay 15 points smoothing (1d+SG15) and standard normal vitiate transformation (SNV) was selected as the pretreatment method and according to the variation between different samples and the characteristic absorption band, 6 468～7 104 cm-1 and 6 468～7 156 cm-1 were chosen as the modeling spectra region. The confusion matrix indicated that Metoprolol Tartrate tablets could be rapidly and effectively identified by two analytical models, which were established using the spectral data collected from two instruments. For these two models, both of the sensitivity and specificity were 100%. This study confirmed that it is feasible to carry out the manufacturer identification of Metoprolol Tartrate tablets by near infrared spectroscopy. Besides, the use of Micro NIR1700 Spectrometer, which is the minimum and portable near infrared spectrometer, provides valuable insights for fast on-site drug screening..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2924 (2015)
Applying Attenuated Total Reflection-Mid-Infrared (ATR-MIR)Spectroscopy to Detect Hairtail Surimi in Mixed Surimi and Their Surimi Products
YOU Zhao-hong, LIU Zi-hao, GONG Chao-yong, YANG Xiao-ling, and CHENG Fang
ATR-MIR spectroscopic analysis was used to classify sliver carp surimi and surimi products adulterated with different levels of hairtail surimi. Five chemometric methods, including SIMCA (soft independent modeling class of analogies), KNN (K-nearest neighbor), SVR (support vector machines regression), PLS-DA (partial lATR-MIR spectroscopic analysis was used to classify sliver carp surimi and surimi products adulterated with different levels of hairtail surimi. Five chemometric methods, including SIMCA (soft independent modeling class of analogies), KNN (K-nearest neighbor), SVR (support vector machines regression), PLS-DA (partial least squares discriminate analysis) and ID3 (interative dicremiser version 3) Decision tree were used to build the classifying models. And the performances of the models were compared. Results showed that for both cooked and uncooked mixed surimi samples, better classifications were obtained using SIMCA model, the percentage of the correct classification reached 96.59% and 96.43%, and the corresponding RMSECV were 0.185 7 and 0.189 8, r value were 0.988 0 and 0.994 1 respectively. The results of this study demonstrated for the first time that ATR-MIR spectroscopy combined with chemometrics method can be used to classify sliver carp surimi and surimi products adulterated with different levels of hairtail surimi..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2930 (2015)
Assessment of the Fluorescence Spectra Characteristics of Dissolved Organic Matter Derived from Organic Waste Composting Based on Projection Pursuit Classification (PPC)
WEI Zi-min, WANG Xing-lei, PAN Hong-wei, ZHAO Yue, XIE Xin-yu, ZHAO Yi, ZHANG Lin-xue, and ZHAO Tao-zhi
The characteristics of fluorescence spectra of dissolved organic matter (DOM) derived from composting is one of the key ways to assess the compost maturity. However, the existing methods mainly focus on the qualitative description for the humification degree of compost. In this paper, projection pursuit classification The characteristics of fluorescence spectra of dissolved organic matter (DOM) derived from composting is one of the key ways to assess the compost maturity. However, the existing methods mainly focus on the qualitative description for the humification degree of compost. In this paper, projection pursuit classification (PPC) was conducted to quantitative assess the grades of compost maturity, based on the characteristics of fluorescence spectra of DOM. Eight organic wastes (chicken manure, swine manure, kitchen waste, lawn waste, fruits and vegetables waste, straw, green waste, and municipal solid waste) composting were conducted, the germination percentage (GI) and fluorescence spectra of DOM were measured during composting. Statistic analysis with all fluorescence parameters of DOM indicated that I436/I383 (a ratio between the fluorescence intensities at 436 and 383 nm in excitation spectra), FLR (an area ratio between fulvic-like region from 308 to 363 nm and total region in emission spectra), PHA/Pro (a regional integration ratio between humic acid-like region to protein-like region in excitation emission matrix (EEM) spectra), A4/A1 (an area ratio of the last quarter to the first quarter in emission spectra), r(A,C) (a ratio between the fluorescence intensities of peak A and peak C in EEM spectra) were correlated with each other (p<0.01), suggesting that this fluorescence parameters could be considered as comprehensive evaluation index system of PPC. Subsequently, the four degrades of compost maturity included the best degree of maturity (Ⅰ, GI>80%), better degree of compost maturity (Ⅱ, 60%
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2940 (2015)
Terahertz Spectroscopy of Biotin and Pyridoxine
JIANG Ling, LI Miao, LI Chun, SUN Hai-jun, XU Li, and LIU Yun-fei
Terahertz (THz) absorption spectra of the biotin and pyridoxine were studied using Fourier transform infrared spectroscopy (FTIR) at room temperature. These spectra exhibit enhanced absorption in THz range because of strong intramolecular and intermolecular vibration modes. In the experiment, the samples were mixed witTerahertz (THz) absorption spectra of the biotin and pyridoxine were studied using Fourier transform infrared spectroscopy (FTIR) at room temperature. These spectra exhibit enhanced absorption in THz range because of strong intramolecular and intermolecular vibration modes. In the experiment, the samples were mixed with high density polyethylene powder, which was used as spectrophotometric grid. The absorption spectra show worse consistency at higher frequencies for the high ratio of the samples to polyethylene. It indicates that the absorbance of the biotin and pyridoxine increased with frequency. Molecular vibrational spectral calculations based on density functional theory (DFT) show strong correlation with the experiment. We investigated the absorption spectra of isolated molecules (single molecule, two molecules, three molecules) and unit cell of crystal to clarify the mechanism of the spectra change due to intramolecular and intermolecular vibration and rotation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2946 (2015)
Preparation and SERS Study of Silver Microstructures with Dendritic Shape
ZHANG Xiao-tong, ZHAO Chun-liu, ZHOU Yu-meng, DONG Qian-min, LANG Ting-ting, and JIN Shang-zhong
In the surface ehanced Raman scattering (SERS) technology, not only to improve the making process of SERS substrates, to be fast and easily, but also to enhance the SERS enhance factor, an easy replacement reaction between zinc and silver nitrate solution has been adopted to prepare silver micro-structures SERS-active In the surface ehanced Raman scattering (SERS) technology, not only to improve the making process of SERS substrates, to be fast and easily, but also to enhance the SERS enhance factor, an easy replacement reaction between zinc and silver nitrate solution has been adopted to prepare silver micro-structures SERS-active substrate. The silver micro-substrates have many advantages. These substrates have good stability, well preservation, an easy making method and a fast making process. The surface profile of the silver microparticles is investigated by scanning electron microscope (SEM). The silver microstructures are dendritic shape in a symmetrical fashion with symmetrical distribution. When the time of the replace reaction is 40, 50 and 60 s, respectively, the average lengths of “trunks” in the silver dendritic microsubstractes are about 3, 5 and 10 μm, and the lengths of the “branches” are about 700 nm, 2 μm and 3 μm, respectively. The result shows that the longer time the replacement reaction takes, the longer lengths of the “trunks” and “branches” in the silver dendritic microsubstractes become. With the time of replace reaction increasing, the “trunk” and “branch” in the silver dendritic microsubstractes grow longer and a large amount of nano-level “leaves” grow out from the “branches” of the silver dendritic microsubstractes, so the silver micro size dendrates have nano level structure on surface. In order to investigate the SERS-active substrates application in SERS, a Fourier transform Raman spectrograph with a 1 064 nm laser wavelength is used to measure the SERS spectra. And good SERS spectra have been obtained by using dendritic silver microsubstrates on the silicon chip as a SERS substract, and Rhodamine 6G (R6G) as a molecule probe. It is found that the silver micro-substrates have good Raman characteristics. And comparing these SERS spectra, it gets the conclution that the spectra with best SERS enhance effect are obtained when R6G is obsorbed on the silver dendritic micro-substractes whose preparing time is 40s, and at that time, the analytical enhancement factor for SERS signals is approximately 103. And when the silicon ships are dealed with surfactants Polyvinylpyrrolidone (PVP) and keeping the other conditions the same as before, the SERS enhance effect of the spectra becomes better, and the enhancement factor turn to be approximately 104. What’s more, the silver microstructures can be preserved several monthes under deionized water and the repeatment of the expriment result is well in general..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2952 (2015)
Synthesis, Growth and Spectroscopic Studies of Piperazinium Paranitrophenolate Monohydrate Crystals
N. Swarnasowmya, and S. Sampath Krishnan
A new piperazinium 4-nitro phenolate monohydrate single crystal (PNP) was grown by employing the solution growth technique piperazine and 4-nitrophenol, were the source material used for the growth, acetonitrile is used as solvent. The grown crystal was characterized by Single X-ray analysis and it shows that piperazinA new piperazinium 4-nitro phenolate monohydrate single crystal (PNP) was grown by employing the solution growth technique piperazine and 4-nitrophenol, were the source material used for the growth, acetonitrile is used as solvent. The grown crystal was characterized by Single X-ray analysis and it shows that piperazinium 4-nitrophenol monohydrate crystallizes in the monoclinic space group P2 1/c, with cell parameters a=10.902 5(4), b=6.226 1(3), c=14.031 8(5), and z=4. The lattice parameters of the substances were also determined by using powder diffraction methods. The functional groups are identified by using FTIR spectral analysis. The absorbance of title compound were analyzed using UV-Vis spectra. The thermo analytical properties of the crystal were studied using TG, DTA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2958 (2015)
Heavy Metals Contents and Speciation in Surface Sediments from Gansu, Ningxia and Inner Mongolia Sections of the Yellow River of China
LIU Jing-jun, LAI Zi-juan, DENG Feng-yu, ZHOU Shan-shan, ZHANG Li-yang, and LIU Ying
So far, many investigations had been made on the concentration and species distribution of heavy metals in aquatic environments. However, there are only a few studies on heavy metals in upper reaches of the Yellow River, especially in Gansu, Ningxia and Inner Mongolia sections. We have literatures related to the YellowSo far, many investigations had been made on the concentration and species distribution of heavy metals in aquatic environments. However, there are only a few studies on heavy metals in upper reaches of the Yellow River, especially in Gansu, Ningxia and Inner Mongolia sections. We have literatures related to the Yellow River, in this work, we remarkably discussed about the contents, speciation and potential risks of Cd, Pb, Cr, V, Co, Ni, Cu, and Zn in surface sediments from 12 sampling sites in Gansu, Ningxia, and Inner Mongolia sections of the Yellow River of China in 2011 year wet season by high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) and sequential extraction procedure of BCR method. The results indicated that the metals contents were arranged as Cr>V>Zn>Cu>Ni>Pb>Co>Cd in all sites. Comparing with the background value of soil in local section, Cd showed the highest level at S5 (1.30 μg·g-1), which was almost 13 times higher than the background value (0.103 μg·g-1). Pollution assessment indicated that Cd presented a strong polluted status with the geo-accumulation index (Igeo) value of 3.08 at S5, moderately to strong polluted status with the Igeo ranged from 2.02 to 2.90 in Inner Mongolia section (S1—S4). Moreover, enrichment factor (EF) showed that all heavy metals in these sediments have been influenced by anthropogenic activities. According to potential ecological risk index (RI), S5 and S3 demonstrated high ecologic risk of heavy metals, while other sampling sites showed moderately ecological risk. The results of BCR exhibited that Cd was the most available metal, followed by Co and Ni, while V and Cr were unavailable in the sediments. Risk assessment code (RAC) exhibited high risk for Cd at S1—S4 and very high risk at S5, while medium risk for Ni and Co at all sites. The results and conclusions may be important information and therefore of interest to the relevant departments of the governments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2963 (2015)
A Study on Effect of Water Background on Canopy Spectral of Wetland Aquatic Plant
LIU Guang, TANG Peng, CAI Zhan-qing, WANG Tian-tian, and XU Jun-feng
Aquatic vegetation is the core of the wetland ecosystem, and it’s also the main factor influencing the wetland ecosystem functions. In recent years, satellite remote sensing technology has been widely used in the investigation, classification and protection fields of wetland vegetation resources. Because of its unique Aquatic vegetation is the core of the wetland ecosystem, and it’s also the main factor influencing the wetland ecosystem functions. In recent years, satellite remote sensing technology has been widely used in the investigation, classification and protection fields of wetland vegetation resources. Because of its unique growth environment, aquatic vegetation, the canopy spectrum of aquatic vegetation will be affected by water background elements including air-water interface, plankton in the water, sediment content, transparency, water depth, sediment, and the other optically active ingredients. When the remote sensing technology for wetland aquatic vegetation canopy spectral studies, should be considered the growth environment differences between aquatic and terrestrial vegetation. However, previous studies did not get the attention it deserves. This paper choose a typical water plant (Iris tentorium Maxim) as the research object, simulate the growth environment of wetland aquatic plants, use the feature spectrometer measurements the spectral reflectance of Iris tentorium Maxim vegetation canopy under different water depth gradient background (400~2 400 nm). Experimental results show that there is a significant negative correlation between background water depth and Iris canopy reflectance. Visible light band absolute correlation coefficient is above 0.9, near infrared band absolute correlation coefficient is above 0.8. In visible light and near infrared band, with water depth increases, the Iris canopy reflectance decreases obviously. Finally based on the highest correlation band of visible light and near infrared region (505, 717, 1 075 and 2 383 nm) established the linear equation between background water depth and the canopy reflectance, obtained the related parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 2970 (2015)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 10, 1 (2015)
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