Journals >Spectroscopy and Spectral Analysis
Contents
2014
Volume: 34 Issue 3
62 Article(s)
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Research Article
Spectra Modulated Surface Plasmon Resonance Sensor Based on Side Polished Multi-Mode Optical Fiber
LUO Yun-han, CHEN Xiao-long, XU Meng-yun, GE Jia, ZHANG Yi-long, HE Yong-hong, TANG Jie-yuan, YU Jian-hui, ZHANG Jun, CHEN Zhe, and CHEN Xing-dan
Surface plasmon resonance, which utilizes the resonance of optical evanescent wave with the metal surface plasmon wave, has been developed into a high sensitivity, rapid, label-less measurement method for chemical and biological analysis. In order to improve the spectral sensitivity in refractive index for a side polisSurface plasmon resonance, which utilizes the resonance of optical evanescent wave with the metal surface plasmon wave, has been developed into a high sensitivity, rapid, label-less measurement method for chemical and biological analysis. In order to improve the spectral sensitivity in refractive index for a side polished fiber surface plasmon resonance sensor, the whole cladding layer and part of core of a multimode fiber was polished off. Additionally, an extra chrome layer with relatively high refractive index was coated on the polished zone before a gold film. The results showed that the sensor can measure the refractive index range from 1333 to 1431 RIU, with the average spectral sensitivity of 411×103 nm·RIU-1, which is better than the reported results. Especially, in the refractive index range of 1417~1431 RIU, the sensitivity reaches to 109×104 nm·RIU-1. The minimum resolution of approximately 36×10-5 RIU was estimated by a combination analysis with the sensor sensitivity and stability. The superiorities possessed by the proposed sensor in high sensitivity, wide detection range, small size and good stability and reproducibility, etc., make it a good candidate for food testing, environmental monitoring, biomedical testing and other related fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 577 (2014)
Research on Diagnosis of Gas-Liquid Detonation Exhaust Based on Double Optical Path Absortion Spectroscopy Technique
Lv Xiao-jing, LI Ning, and WENG Chun-sheng
The effect detection of detonation exhaust can provide measurement data for exploring the formation mechanism of detonation, the promotion of detonation efficiency and the reduction of fuel waste. Based on tunable diode laser absorption spectroscopy technique combined with double optical path cross-correlation algorithThe effect detection of detonation exhaust can provide measurement data for exploring the formation mechanism of detonation, the promotion of detonation efficiency and the reduction of fuel waste. Based on tunable diode laser absorption spectroscopy technique combined with double optical path cross-correlation algorithm, the article raises the diagnosis method to realize the on-line testing of detonation exhaust velocity, temperature and H2O gas concentration. The double optical path testing system is designed and set up for the valveless pulse detonation engine with the diameter of 80 mm. By scanning H2O absorption lines of 1343nm with a high frequency of 50 kHz, the on-line detection of gas-liquid pulse detonation exhaust is realized. The results show that the optical testing system based on tunable diode laser absorption spectroscopy technique can capture the detailed characteristics of pulse detonation exhaust in the transient process of detonation. The duration of single detonation is 85 ms under laboratory conditions, among which supersonic injection time is 57 ms and subsonic injection time is 193 ms. The valveless pulse detonation engine used can work under frequency of 11 Hz. The velocity of detonation overflowing the detonation tube is 1 172 m·s-1, the maximum temperature of detonation exhaust near the nozzle is 2 412 K. There is a transitory platform in the velocity curve as well as the temperature curve. H2O gas concentration changes between 0~7% during detonation under experimental conditions. The research can provide measurement data for the detonation process diagnosis and analysis, which is of significance to advance the detonation mechanism research and promote the research of pulse detonation engine control technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 582 (2014)
Remote Sensing of Seasonal Variation in Column Concentration of Atmospheric CO2 and CH4 in Hefei
CHENG Si-yang, GAO Min-guang, XU Liang*, JIN Ling, LI Sheng, TONG Jing-jing, WEI Xiu-li, LIU Jian-guo, and LIU Wen-qing
In order to observe two kinds of greenhouse gases, CO2 and CH4, making the biggest contribution to global warming, a ground-based Fourier transform near-infrared spectral remote sensing system was developed to record the perpendicular incidence sun spectra from February 2012 to April 2013 in Hefei continuously. The meaIn order to observe two kinds of greenhouse gases, CO2 and CH4, making the biggest contribution to global warming, a ground-based Fourier transform near-infrared spectral remote sensing system was developed to record the perpendicular incidence sun spectra from February 2012 to April 2013 in Hefei continuously. The measured total transmittances in the atmosphere were obtained from perpendicular incidence sun spectra. Methods of line-by-line and low-order polynomial approximation were used to model the total atmospheric transmittances in forward model. The measured transmittance spectra were fitted iteratively using the modeled transmittance spectra in the regions of CO2 6 150～6 270 and CH4 5 970～6 170 cm-1 in order to obtain their column concentrations. The column-average dry-air mole fractions of CO2 and CH4 were obtained with the internal standard function of O2 column concentrations. CO2 and CH4 daily average values of column-average dry-air mole fractions changed with a larger fluctuation and obvious seasonal periodicity. Their monthly average values were consistent as a whole, although there were different characteristics. Compared with the results reported by Japanese greenhouse-gas satellite in the area of Waliguan, there was a time lag corresponding to peak and trough of CO2 content and the change from peak to trough costed a long time. CH4 content showed variation tendency of unique peak and trough, higher in summer and lower in winter, compared with average values of nationwide CH4 column concentrations based on SCIAMACHY data. The variation characteristics were related to complex factors such as the balance of source and sink, meteorological and climate conditions, and required long-term observation and further study..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 587 (2014)
Research on Explosive Temperature Network Monitoring System Based on the Linear Frequency Shift of Spectrum
WEN Qiang, LIAN Su-jie, ZHANG Chen, ZHAO Hui, ZHAO Yu, WANG Gao, XU De-gang, and YAO Jian-quan
In order to obtain the different position temperature changes in the process of explosive casting accurate, stability and comprehensive, we designed the temperature monitoring system based on fiber Bragg grating spectral shift. Through the fiber-optic network, the system can monitor the different point temperature of mIn order to obtain the different position temperature changes in the process of explosive casting accurate, stability and comprehensive, we designed the temperature monitoring system based on fiber Bragg grating spectral shift. Through the fiber-optic network, the system can monitor the different point temperature of melt-cast explosive real-time. According to the function of linear frequency shift of fiber Bragg grating wavelength with the grating of temperature, we get the temperature of different positions. Four channels share a broadband light source with a coupler. The Bragg wavelengths of the 5 gratings of each fiber are separated from each other. Using the gratings designed, spliced and packaged by our own, we can obtain temperature data through the demodulator. The temperature data was processed by the Origin to draw diagram time-temperature curve. The results show that the measured temperature data of the fiber Bragg grating can meet the requirements of experiment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 592 (2014)
Analysis of Lorentzian Line Shape Function Broadened by Non-Sinusoidal Wavelength Modulation
SUN You-qun, WANG Yun-tao, RUAN Chi, and XU Song-song
In the present work, the Fourier analysis of Lorentzian line shape broadened by non-sinusoidal wavelength modulation was investigated, in which the third order and above harmonic items were ignored. The analytical expression of n-order Fourier coefficient was brought out, where a variable K named harmonic distortion toIn the present work, the Fourier analysis of Lorentzian line shape broadened by non-sinusoidal wavelength modulation was investigated, in which the third order and above harmonic items were ignored. The analytical expression of n-order Fourier coefficient was brought out, where a variable K named harmonic distortion to characterize the ratio of the second harmonic to the first harmonic was introduced. Numerical simulations based on the cases of K>001 and K<001 were carried out, and the result shows: non-sinusoidal modulation has little effect compared with the sinusoidal modulation when K value is less than 001, however, if K value is about 01 or higher, the center of the Fourier amplitude curve would deviate from the origin of coordinates. With the increase in the harmonic distortion, the deviation of the curve grows, and high order harmonics are more sensitive to the non-sinusoidal modulation compared with the low order harmonics. In addition, when harmonic distortion cannot be ignored, for example K>001, the effect of different depths of modulation on the odd and even order harmonic amplitude curve is significant. And the numerical simulation shows there exists an optimum value of modulation depth which could minimize the impact of the harmonic distortion, and both large K value and small K value would cause a great error. The conclusion of this work could be applied in error analysis of wavelength modulation spectroscopy system. And the results are helpful to deepening understanding of WMS and would be the important reference for some kind of frequency stabilization technology in laser instrument..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 597 (2014)
Investigation of Light Penetration Depth and Distribution Inside Citrus Tissue
WU Chen-kai, ZHANG Liang, SHEN Huang-tong, and FU Xia-ping
Experiment was carried out to explore the light intensity change inside citrus samples in the present study. An experimental platform was set up, including a light box, a spectrometer, a sample stage, an optic fiber probe, light sources, etc. The sample stage is adjustable in three dimensions. The optic fiber probe wasExperiment was carried out to explore the light intensity change inside citrus samples in the present study. An experimental platform was set up, including a light box, a spectrometer, a sample stage, an optic fiber probe, light sources, etc. The sample stage is adjustable in three dimensions. The optic fiber probe was used to measure the light changes by observing the light attenuation and intensity variation within the citrus tissues. A 632 nm laser source and a 50 W tungsten halogen lamp light source were used. Light intensity and transmittance were investigated at different positions within the citrus fruit. The band with most significant intensity difference was selected to analyze the light intensity and transmittance trends in different positions inside the citrus fruit. In order to examine the influence significance of the sample factor on test results, SPSS software was used to do the analysis of variation (ANOVA) of different samples. The results showed that light intensity and transmittance have a positive correlation with puncture depth, while citrus peel and stone have a more obvious attenuation effect than citrus flesh, and the influence of the sample factor on the test results is not significant. Further research can be carried out by improving the experimental device. The method used and results obtained in this study are valuable for studies on light transmission properties inside fruit tissue, not only for citrus but also for other kinds of fruits..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 601 (2014)
Research on Glucose Measuring Technique by Surface Plasmon Resonance Based on Thiol Coupling
LI Da-chao, YANG Di, YANG Jia, ZHANG Jing-xin, WU Peng, YU Hai-xia, and XU Ke-xin
In the glucose measuring technique by surface plasmon resonance, D-galactose/D-glucose binding protein (GGBP) that can specifically adsorb glucose was introduced, and high-precision specific detection of glucose concentration was realized. In the present paper, the GGBP protein was bound on the surface of SPR sensor thIn the glucose measuring technique by surface plasmon resonance, D-galactose/D-glucose binding protein (GGBP) that can specifically adsorb glucose was introduced, and high-precision specific detection of glucose concentration was realized. In the present paper, the GGBP protein was bound on the surface of SPR sensor through thiol coupling method. GGBP binding experiment was carried out on SPR sensor and then glucose concentration experiment was conducted with this sensor. The results indicated that the SPR sensor had good linearity, stability and repeatability in the range of 01~10 mg·dL-1. SPR sensor bound with GGBP would have great potential and vast development prospects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 605 (2014)
Spectral Scanning Measurement of High-Precision Solar Irradiance-Meter
LIU En-chao, LI Xin, ZHANG Yan-na, LI Wen-wei, and ZHENG Xiao-bing
In order to measure the radiation of the sun absolutely and retrieve the characterization of the atmosphere precisely, a high-precision solar spectral irradiance meter working in 04～10 μm band was developed. A Fèry prism was employed to disperse the incident sunlight and a closed-loop control method was adopted In order to measure the radiation of the sun absolutely and retrieve the characterization of the atmosphere precisely, a high-precision solar spectral irradiance meter working in 04～10 μm band was developed. A Fèry prism was employed to disperse the incident sunlight and a closed-loop control method was adopted for spectral scanning in this solar irradiance meter. The design of spectral scanning measurement was depicted in detail. The design requirements of Fèry prism were given and spectral dispersion was achieved by single element. The trap detectors were used to ensure precise spectral measurement. According to the parameters of the trap detectors, the demands and method of temperature control were introduced. The design of spectral scanning structure was introduced, and wavelengths were positioned accurately. The requirements for parameters, stability and power supply of voice coil actuator were given and the wavelength position error of 0025% was achieved. Spectral scanning measurement of 04～10 μm was accomplished in outdoor experiments. A comparison was carried out with visible-short wave infrared spectrometer and auto-sunphotometer(CE318). Results indicate that absorption peak locations of spectral scanning measurement of irradiance meter are correct, and the relative deviation from CE318 measurements is less than 013% for all day, and the relative deviation of optical depth in visible and near infrared band is less than 2% and 5%, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 609 (2014)
Study on the Thermal Radiation Polarization Characteristics of Ice
WANG Ting-ting, ZHAO Yun-sheng, ZHANG Hong-yan*, ZHANG Xia, and ZHANG Li-li
As an important parameter of the global energy balance, climate, hydrological and ecological model, ice directly affects the energy balance of the earth-atmosphere system, weather and climate. It is of great significance to use the thermal infrared polarization technology to study ice thermal radiation. For the ice monAs an important parameter of the global energy balance, climate, hydrological and ecological model, ice directly affects the energy balance of the earth-atmosphere system, weather and climate. It is of great significance to use the thermal infrared polarization technology to study ice thermal radiation. For the ice monitoring and the impact of global climate change on the ice, studies on ice thermal radiation polarization characteristics were conducted based on the wavelength, detection angle and azimuth angle. The results show that the wavelength has an obvious impact on the ice thermal radiation polarization properties. The polarized radiance of four bands shows that LCH1>LCH3>LCH4>LCH2 while the polarization brightness temperature shows that TCH4>TCH1>TCH2>TCH3. It’s better to use the brightness temperature of the third channel than the radiance to study the thermal radiation polarization. The detection angle affects the ice thermal radiation polarization characteristics greatly and there are some differences between the polarization angles. The brightness temperature of ice is the lowest in the detection angle of 10° and the polarization angle of 30°, which are non-accidental factors. These was closely related to ice physical and chemical properties. The degree of ice polarization performance shows that P0
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 614 (2014)
Study on Multi-Angular Polarized Spectrum Characteristics of Leaf Based on Some Indoor Experimental Data
MENG Xia, XIE Dong-hui, WANG Yan, JIA Ying-fang, and YAN Guang-jian
In the present study, we acquired multi-angular polarized spectrum of three kinds of leaves with different surface structures, and calculated the multi-angular spectral degree of polarization DOP based on Stokes parameters to explore its variation tendency with wavelength and the relationship between the leaf polarizedIn the present study, we acquired multi-angular polarized spectrum of three kinds of leaves with different surface structures, and calculated the multi-angular spectral degree of polarization DOP based on Stokes parameters to explore its variation tendency with wavelength and the relationship between the leaf polarized reflectance and its physiological parameters and the relative observational geometric condition. The results show that although the spectral degree of polarization of the 3 kinds of leaves has obvious differences in value because of the leaf surface structures, the general trend of the DOP curve keeps consistent, and this trend could be explained by analyzing the properties of both specular and diffuse components of the leaf reflectance. The peak value of the DOP appears in the specular direction of the principal plane, and grows with the increase in the incident zenith angle. The analysis of the data demonstrates that compared to the other two experimental bands, the near infrared band shows a better discrimination in showing the relationship between DOP and the observational geometric configuration for all the three kinds of leaves, but the value of the DOP is smaller. Considering the effect of variation in chlorophyll content, DOP of the red band has more stable value than the near infrared band, whereas the water content has barely influence in both of the bands..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 619 (2014)
Photoluminescence of In-Doped Zinc Oxide Nanopowders Synthesized by Precipitation Method
LU Hong-bo, LIU Xiao-lin, GU Mu, NI Chen, HUANG Shi-ming, and LIU Bo
In-doped ZnO nanopowders were prepared by precipitation. The influence of the processing parameters, such as In doping concentration, calcination temperature, reactant ratio and type of precipitant on the grain size, structure and photoluminescence (PL) of In/ZnO nanopowders was detailed analyzed by using X-ray diffracIn-doped ZnO nanopowders were prepared by precipitation. The influence of the processing parameters, such as In doping concentration, calcination temperature, reactant ratio and type of precipitant on the grain size, structure and photoluminescence (PL) of In/ZnO nanopowders was detailed analyzed by using X-ray diffraction (XRD) and photoluminescence spectrum. The experimental results indicated that with the increase in the In doping level (the molar ratio of In3+/Zn2+ increased from 0% to 5%), the crystallization and the UV emission of ZnO nanopowders were reduced because of the increase of impurity defects. And the UV emission band would have a red-shift from 389 to 419 nm, which could be resulted from the effects of merging of donor and conduction bands, and potential fluctuations of impurity energy level. The calcination temperature will play an important role in synthesis of luminescence materials. When the calcination temperature was raised from 500 to 600 ℃, the grain size of In/ZnO nanopowder increased gradually, and the dominated UV emission band was improved due to the enhanced crystallization of the nanopowder. If the temperature was raised up to 800 ℃, the crystallization of the sample was further improved, leading to an enhanced intensity of UV emission. Additionally, near this temperature, the oxygen vacancy is easier to be produced owing to the improvement of the kinetic energy for the ions in lattice, which induces in the enhancement of the green emission band peaking at 525 nm. For the temperature up to 1 000 ℃, the UV emission band was suppressed due to the production of excessive oxygen vacancy, and the In/ZnO nanopowder exhibited a dominated green emission. The luminescence performance of the In/ZnO nanopowder is also much affected by the reactant ratio. The reaction rate is improved by the increase of the NH4HCO3/Zn(NO3)2 molar ratio, which will decrease both grain size of In/ZnO nanopowder and emission intensity of UV band. Furthermore, the effect of the precipitant on the luminescence was examined. It is obviously that the NH4HCO3 and NaOH precipitants will remarkably affect the crystallization of the precursor powder, but nearly have no effect on the luminescence property of the final nanopowder products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 625 (2014)
Preparation and Up-Conversion Luminescence Properties of Yb3+/Tm3+ Co-Doped Sb2O4 Powder
LI Rui-qin, QIU Jian-bei, YANG Zheng-wen, LIAO Jia-yan, WU Hang-jun, LAI Shen-feng, SONG Zhi-guo, YANG Yong, ZHOU Da-cheng, and WANG Rong-fei
The Sb2O4∶Yb3+, Tm3+ up-conversion luminescence powder with excellent physical, chemical stability and relative low phonon energy was synthesized by the high temperature solid-state reaction and its up-conversion luminescence property was investigated. Under the 980 nm excitation, infrared and blue up-conversion emissiThe Sb2O4∶Yb3+, Tm3+ up-conversion luminescence powder with excellent physical, chemical stability and relative low phonon energy was synthesized by the high temperature solid-state reaction and its up-conversion luminescence property was investigated. Under the 980 nm excitation, infrared and blue up-conversion emissions centered at 800 and 480 nm were observed, which were assigned to the 1G4→3H6 and 3H4→3H6 transitions of Tm3+, respectively. The influence of Yb3+ and Tm3+ concentration on the up-conversion emission property was also obtained. The up-conversion luminescence increases with increasing of Yb3+ and Tm3+ concentration. Additionally, the up-conversion luminescence mechanism was discussed based on the dependence of Tm3+ up-conversion luminescence on pump power. It is interesting that two photon excitation processes for blue and infrared emission were observed in the Sb2O4∶Yb3+, Tm3+ powder under a 980 nm excitation. Based on the energy level diagram of Tm3+ and Yb3+ ions, we think that two photons blue emission is contributed to the cooperation energy transfer between Tm3+ and Yb3+ ions. We believe that the Sb2O4∶Yb3+, Tm3+ up-conversion luminescence powder will have potential application for new optical devices in up-conversion color displays, sensors, detection of infrared radiation, and lasers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 630 (2014)
Analysis of Different Parts and Tissues of Panax Notoginseng by Fourier Transform Infrared Spectroscopy
LI Jian-rui, CHEN Jian-bo, ZHOU Qun, SUN Su-qin, and Lv Guang-hua
The techniques of Fourier transform infrared (FTIR) spectroscopy were applied to analyze the different parts and tissues of Panax Notoginseng (Sanqi, SQ), i.e. rhizome, main root, rootlet, fibrous root, xylem, cambium, phloem and epidermis. Both the FTIR spectra and second derivative spectra of these various parts and The techniques of Fourier transform infrared (FTIR) spectroscopy were applied to analyze the different parts and tissues of Panax Notoginseng (Sanqi, SQ), i.e. rhizome, main root, rootlet, fibrous root, xylem, cambium, phloem and epidermis. Both the FTIR spectra and second derivative spectra of these various parts and tissues of SQ samples were found to be similar. Their dominant component is starch resulting from the characteristic peaks of starch observed at 3 400, 2 930, 1 645, 1 155, 1 080 and 1 020 cm-1 on the spectra of all these SQ samples. However, the varieties of peaks were found on the spectra among these specific samples. The rhizome contains more saponins than others on the basis of the largest ratio of the peak intensity at 1 077 cm-1 to that at 1 152 cm-1. The peaks located at 1 317 and 780 cm-1 on the FTIR spectra of the rhizome and its epidermis indicate that the two parts of SQ samples contain large amount of calcium oxalate, and its content in the latter is relative larger than that in former. The fibrous root contains much amount of nitrate owing to the obvious characteristic peaks at 1 384 and 831 cm-1. For the difference among the various tissues of SQ samples, the peaks at 2 926, 2 854 and 1 740 cm-1 on the FTIR spectra of epidermis is the strongest among the various tissues of main root indicating the largest amount of esters in epidermis. Protein was also found in the cambium of the main root based on the relative strong peaks of amide Ⅰ and Ⅱ band at 1 641 and 1 541 cm-1, respectively. The results indicate that FTIR spectra with its second derivative spectra can show the characteristic of the various parts and tissues of SQ samples in both the holistic chemical constituents and specific chemical components, including organic macromolecule compounds and small inorganic molecule compounds. FTIR spectroscopy is a useful analytical method for the genuine and rapid identification and quality assessment of SQ samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 634 (2014)
Genetic Algorithm Based Multi-Objective Least Square Support Vector Machine for Simultaneous Determination of Multiple Components by Near Infrared Spectroscopy
XU Bing, WANG Xing, Dhaene Tom, SHI Xin-yuan, Couckuyt Ivo, BAI Yan, and QIAO Yan-jiang
The near infrared (NIR) spectrum contains a global signature of composition, and enables to predict different properties of the material. In the present paper, a genetic algorithm and an adaptive modeling technique were applied to build a multi-objective least square support vector machine (MLS-SVM), which was intendedThe near infrared (NIR) spectrum contains a global signature of composition, and enables to predict different properties of the material. In the present paper, a genetic algorithm and an adaptive modeling technique were applied to build a multi-objective least square support vector machine (MLS-SVM), which was intended to simultaneously determine the concentrations of multiple components by NIR spectroscopy. Both the benchmark corn dataset and self-made Forsythia suspense dataset were used to test the proposed approach. Results show that a genetic algorithm combined with adaptive modeling allows to efficiently search the LS-SVM hyperparameter space. For the corn data, the performance of multi-objective LS-SVM was significantly better than models built with PLS1 and PLS2 algorithms. As for the Forsythia suspense data, the performance of multi-objective LS-SVM was equivalent to PLS1 and PLS2 models. In both datasets, the over-fitting phenomena were observed on RBFNN models. The single objective LS-SVM and MLS-SVM didn’t show much difference, but the one-time modeling convenience allows the potential application of MLS-SVM to multicomponent NIR analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 638 (2014)
Application of Near Infrared Spectroscopy to Qualitative Identification and Quantitative Determination of Puccinia striiformis f. sp. tritici and P. recondita f. sp. tritici
LI Xiao-long, MA Zhan-hong, ZHAO Long-lian, LI Jun-hui, and WANG Hai-guang
To realize qualitative identification and quantitative determination of Puccinia striiformis f. sp. tritici (Pst) and P. recondita f. sp. tritici (Prt), a qualitative identification model was built using near infrared reflectance spectroscopy (NIRS) combined with distinguished partial least squares (DPLS), and a quantiTo realize qualitative identification and quantitative determination of Puccinia striiformis f. sp. tritici (Pst) and P. recondita f. sp. tritici (Prt), a qualitative identification model was built using near infrared reflectance spectroscopy (NIRS) combined with distinguished partial least squares (DPLS), and a quantitative determination model was built using NIRS combined with quantitative partial least squares (QPLS). In this study, 100 pure samples including 50 samples of Pst and 50 samples of Prt were obtained, and 120 mixed samples including three replicates of mixed urediospores of the two kinds of pathogen in different proportions (the content of Pst was within the range of 25%～100% with 2.5% as the gradient) were obtained. Then the spectra of the samples were collected using MPA spectrometer, respectively. Both pure samples and mixed samples were divided into training set and testing set with the ratio equal to 2∶1. Qualitative identification model and quantitative determination model were built using internal cross-validation method in the spectral region 4 000～10 000 cm-1 based on the training sets from pure samples and mixed samples, respectively. The results showed that the identification rates of the Pst-Prt qualitative identification model for training set and testing set were both up to 100.00% when scatter correction was used as the preprocessing method of the spectra and the number of principal components was 3. When ‘range normalization + scatter correction’ was used as the preprocessing method of the spectra and the number of principal components was 6, determination coefficient (R2), standard error of calibration(SEC) and average absolute relative deviation(AARD) of the Pst-Prt quantitative determination model for training set were 9936%, 231% and 894%, respectively, and R2, standard error of prediction (SEP) and AARD for testing set were 9937%, 229% and 540%, respectively. The results indicated that qualitative identification and quantitative determination of Pst and Prt using near infrared spectroscopy technology are feasible and that the Pst-Prt qualitative identification model and the Pst-Prt quantitative determination model built in this study were reliable and stable. A new method based on NIRS was provided for qualitative identification and quantitative determination of plant pathogen in this study..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 643 (2014)
Study of Rapid Prediction of Wood Surface Glossiness by Near Infrared Spectroscopy
LIU Ya-na, YANG Zhong, Lv Bin, ZHANG Mao-mao, and WANG Xing-hua
Surface glossiness is one of the important visual appearance parameters of natural polymer material (wood) and its related products. To realize the fast measurement of natural polymer material surface glossiness is of great significance to the online quality control and assessment of its surface. In order to broaden thSurface glossiness is one of the important visual appearance parameters of natural polymer material (wood) and its related products. To realize the fast measurement of natural polymer material surface glossiness is of great significance to the online quality control and assessment of its surface. In order to broaden the application of near infrared (NIR) spectroscopy in the field of polymer material surface quality control and realize the feasibility of NIR as a fast measurement of surface glossiness , the NIR combined with partial least squares(PLS) analysis were used to analyse the correlations of natural polymer material wood surface glossiness between the NIR predicted and lab measured, and then to investigate the feasibility of NIR to rapidly predict the surface glossiness of natural polymer material wood.The results showed that the wood NIR diffuse reflectance spectroscopy regularly varied with the different wood surface glossiness, from which we can concluded that the NIR spectrums reflected the information of wood surface glossiness. The correlation coefficients of surface glossiness between the PLS models predicted and lab measured were up to 090. Additionally, by changing the degree between the fiber and sample surface, we collected the different wood NIR spectrums, the accuracy of NIR surface glossiness models based on these NIR spectrums had not significantly improved, and models based on the NIR spectrums collected by the 90 degree between the fiber and sample surface performed better..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 648 (2014)
Noninvasive Detection of Hematocrit and the Mean Corpuscular Hemoglobin Concentration Levels by Vis-NIR Spectroscopy
ZHAO Jing, LIN Ling, LU Xiao-zuo, and LI Gang
Hematocrit(HCT) and mean hemoglobin concentration(MCHC) play a very important role in preventing cardiovascular disease and anemia A method was developed on the basis of spectroscopy to detect HCT and MCHC non-invasively and accurately The anatomical study showed that the blood rheology abnormalities and blood viscosHematocrit(HCT) and mean hemoglobin concentration(MCHC) play a very important role in preventing cardiovascular disease and anemia A method was developed on the basis of spectroscopy to detect HCT and MCHC non-invasively and accurately The anatomical study showed that the blood rheology abnormalities and blood viscosity’s changes can cause the changes of tongue, so there is a certain correlation between tongue and blood components Reflectance spectrums from the tongue tips of 240 volunteers were collected, then the tongue pictures were captured and the biochemical analysis results were recorded at the same time The 240 samples were separated into two parts: calibration sample and test sample Spectra were then subjected to a partial least squares regression (PLSR) analysis to develop mathematics models for predicting HCT levels The correlation between the data and prediction of HCT and MCHC yielded calibration samples value of 0998 and 0938 HCT and MCHC levels of test samples predicted by this model from Visible-Near infrared spectra provided a coefficient of determination in prediction of 0979 and 0883 with an average relative error of prediction of 165% and 188%, a root mean square error of prediction of 4066 and 4139 From the experiment results we can see that the model which was built before can better predict the HCT and MCHC, and the results also showed that spectrometry method may provide a promising approach to the noninvasive measurement of human HCT and MCHC with a combination of PLSR analysis.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 652 (2014)
Discrimination of Minnan Oolong Tea Varieties by NIR Spectroscopy
CHENG Quan, YANG Fang, WANG Dan-hong, LIN Zhen-yu, and QIU Bin
The present paper presented a fast and non-destructive method for the discrimination of minnan oolong tea varieties by near-infrared spectroscopy technology. Two hundred ten samples including Tieguanyin, Huangjingui, Benshan, Maoxie and Meizhan were collected in different tea plantations of Minnan. NIR spectra of 1 100The present paper presented a fast and non-destructive method for the discrimination of minnan oolong tea varieties by near-infrared spectroscopy technology. Two hundred ten samples including Tieguanyin, Huangjingui, Benshan, Maoxie and Meizhan were collected in different tea plantations of Minnan. NIR spectra of 1 100～1 300 nm and 1 640～2 498 nm were successfully obtained. Prediction model was built by principal component analysis (PCA), and the effects of multiplicative scatter correction(MSC) and standard normal variate(SNV) on the model were observed and compared. It was indicated that the effect of MSC on the model was superior for the effect of SNV because the classification accuracy of model for the calibration samples reached 96%, and this number to the prediction samples was about 90%. These results demonstrated that the near-infrared spectroscopy method established could be an efficient and accurate way for the discrimination of minnan oolong teas and would have a strong practical value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 656 (2014)
The Influence of Oil Heat Treatment on Wood Decay Resistance by Fourier Infrared Spectrum Analysis
WANG Ya-mei, MA Shu-ling, and FENG Li-qun
Wood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten. Among them heat-treatment is not only environmental and no pollution, also can improve the corrosion resistance and dimension stability of wood. In this test Poplar and Mongolian Seoteh Pine was treated by soybeanWood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten. Among them heat-treatment is not only environmental and no pollution, also can improve the corrosion resistance and dimension stability of wood. In this test Poplar and Mongolian Seoteh Pine was treated by soybean oil as heat-conducting medium, and the heat treatment wood was studied for indoor decay resistance; wood chemical components before and after treatment, the effect of heat treatment on wood decay resistance performance and main mechanism of action were analysed by Fourier infrared spectrometric. Results showed that the mass loss rate of poplar fell from 1937% to 5% and Mongolian Seoteh Pine’s fell from 823% to 315%, so oil heat treatment can effectively improve the decay resistance. Infrared spectrum analysis shows that the heat treatment made wood’s hydrophilic groups such as hydroxyl groups in largely reduced, absorbing capacity decreased and the moisture of wood rotting fungi necessary was reduced; during the heat treatment wood chemical components such as cellulose, hemicellulose were degraded, and the nutrient source of wood rotting fungi growth necessary was reduced. Wood decay fungi can grow in the wood to discredit wood is because of that wood can provide better living conditions for wood decay fungi, such as nutrients, water, oxygen, and so on. The cellulose and hemicellulose in wood is the main nutrition source of wood decay fungi. So the oil heat-treatment can reduce the cellulose, hemicellulose nutrition source of wood decay fungi so as to improve the decay resistance of wood..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 660 (2014)
Producing Area Identification of Letinus Edodes Using Mid-Infrared Spectroscopy
ZHU Zhe-yan, ZHANG Chu, LIU Fei, KONG Wen-wen, and HE Yong
In the present study, Mid-infrared spectroscopy was used to identify the producing area of Letinus edodes, and relevance vector machine (RVM) was put forward to build classification models as a novel classification technique, and they obtained good performances. The head and the tail of the acquired mid-infrared spectrIn the present study, Mid-infrared spectroscopy was used to identify the producing area of Letinus edodes, and relevance vector machine (RVM) was put forward to build classification models as a novel classification technique, and they obtained good performances. The head and the tail of the acquired mid-infrared spectra with the absolute noise were cut off, and the remaining spectra in the range of 3 581～689 cm-1 (full spectra) of Letinus edodes were preprocessed by multiplicative scatter correction (MSC). Five classification techniques, including partial least Squares-discriminant analysis (PLS-DA), soft independent modeling of class analogy (SIMCA), K-nearest neighbor algorithm (KNN), support vector machine (SVM) and RVM, were applied to build classification models based on the preprocessed full spectra. All classification models obtained classification accuracy over 80%, KNN, SVM and RVM models based on full spectra obtained similar and good performances with classification accuracy over 90% in both the calibration set and the prediction set. The weighted regression coefficients (Bw) were used to select effective wave numbers of mid-infrared spectra and 6 effective wave numbers in total were selected on the basis of the weighted regression coefficients of PLS-DA model based on full spectra. PLS-DA, KNN, SVM and RVM models were built using these effective wave numbers. Compared with the classification models based on full spectra, PLS-DA models based on effective wave numbers obtained relatively worse results with classification accuracy less than 80%, and KNN, SVM and RVM obtained similar results in both calibration set and prediction set with classification accuracy over 90%. RVM performed well with classification rate over 90% based on full spectra and effective wave numbers. The overall results indicated that producing area of Letinus edodes could be identified by mid-infrared spectroscopy, while wave number selection and the RVM algorithm could be effectively used in mid-infrared spectroscopy analysis. In this study, mid-infrared spectroscopy was successfully applied to identify the producing area of Letinus edodes, which could provide a new concept for quality analysis of Letinus edodes and other agricultural products, and the application of mid-infrared spectroscopy had practical significance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 664 (2014)
Near Infrared Spectroscopy Synergy Interval Wavelength Selection Method Using the LSSVM Model
PENG Xiu-hui, HUANG Chang-yi, LIU Fei, and LIU Yan
The present paper proposes a wavelength selection algorithm based on nonlinear factors named Synergy interval least squares support vector machines (siLSSVM). siLSSVM combines the interval strategy of wavelength selection method with the idea of synergy interval and overcomes the disadvantages of the traditional waveleThe present paper proposes a wavelength selection algorithm based on nonlinear factors named Synergy interval least squares support vector machines (siLSSVM). siLSSVM combines the interval strategy of wavelength selection method with the idea of synergy interval and overcomes the disadvantages of the traditional wavelength selection methods, i.e. ignoring the nonlinear factors. Taking the near infrared spectrum data of apple sugar as performance verification object of this new algorithm, comparing new algorithm with siPLS, the model performance has been greatly improved. The root-mean-square error (RMSEP) in new algorithm has increased respectively by 3743% and 4788% under the model of PLS and LSSVM, with increases of 604% and 731% in the correlative coefficient (RP). The examples illustrate that siLSSVM can efficiently select the optimum wavelength interval for spectrum data with strong nonlinear factors. This algorithm greatly improves the prediction accuracy and robustness of the model, which provides a new prospect for near infrared spectral with nonlinear factors to select wavelength..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 668 (2014)
Extracting Target from Blurred Midwave Infrared Image Based on Immune Template Clustering
FU Dong-mei, YU Xiao, and TONG He-jun
Extracting targets from a blurred midwave infrared image is a challenging task due to the fuzziness of the image. Inspired by the coordination mechanism between biological innate immunity and adaptive immunity, an immune template clustering targets extraction method is proposed, which based on imaging mechanism and temExtracting targets from a blurred midwave infrared image is a challenging task due to the fuzziness of the image. Inspired by the coordination mechanism between biological innate immunity and adaptive immunity, an immune template clustering targets extraction method is proposed, which based on imaging mechanism and template statistical property of midwave image. Firstly, by learning from the recognition function of innate immunity and maximizing the between-cluster variance, a midwave blurred infrared image is segmented into a target pixel set, a background pixel set and a blurred pixel set. Secondly, according to the presentation function of innate immunity, the frequency domain template features of pixels in midwave blurred infrared image are extracted. Finally, adaptive immune clustering is completed for the blurred pixel set based on frequency domain template feature, in order to divide each blurred pixel into target pixel or background pixel. Experimental results show that the proposed algorithm can extract targets from a midwave blurred infrared image efficiently. Compared with classical edge template and conventional region template methods, the immune template clustering method has better extraction efficiency, absolute error rate and coincidence degree with ground truth..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 673 (2014)
Rapid Identification of Potato Cultivars Using NIR-Excited Fluorescence and Raman Spectroscopy
DAI Fen, Mads Sylvest Bergholt, Arnold Julian Vinoj Benjamin, HONG Tian-sheng, and Zhiwei Huang
Potato is one of the most important food in the world. Rapid and noninvasive identification of potato cultivars plays an important role in the better use of varieties. In this study, The identification ability of optical spectroscopy techniques, including near-infrared (NIR) Raman spectroscopy and NIR fluorescence specPotato is one of the most important food in the world. Rapid and noninvasive identification of potato cultivars plays an important role in the better use of varieties. In this study, The identification ability of optical spectroscopy techniques, including near-infrared (NIR) Raman spectroscopy and NIR fluorescence spectroscopy, for invasive detection of potato cultivars was evaluated. A rapid NIR Raman spectroscopy system was applied to measure the composite Raman and NIR fluorescence spectroscopy of 3 different species of potatoes (98 samples in total) under 785 nm laser light excitation. Then pure Raman and NIR fluorescence spectroscopy were abstracted from the composite spectroscopy, respectively. At last, the partial least squares- discriminant analysis (PLS-DA) was utilized to analyze and classify Raman spectra of 3 different types of potatoes. All the samples were divided into two sets at random: the calibration set (74samples) and prediction set(24 samples). the model was validated using a leave-one-out, cross-validation method. The results showed that both the NIR-excited fluorescence spectra and pure Raman spectra could be used to identify three cultivars of potatoes. The fluorescence spectrum could distinguish the Favorita variety well (sensitivity: 1, specificity: 086 and accuracy: 092), but the result for Diamant (sensitivity: 075, specificity: 075 and accuracy: 075) and Granola (sensitivity: 016, specificity: 089 and accuracy: 071) cultivars identification were a bit poorer. We demonstrated that Raman spectroscopy uncovered the main biochemical compositions contained in potato species, and provided a better classification sensitivity, specificity and accuracy (sensitivity: 1, specificity: 1 and accuracy: 1 for all 3 potato cultivars identification) among the three types of potatoes as compared to fluorescence spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 677 (2014)
Monolithic Column-Gold Composite Substrate Preparation and Application to SERS Detection of Pigment
XIE Yun-fei, LI Yan, YU Hui, QIAN He, and YAO Wei-rong
In the present study, we developed a novel SERS substrate with the porous monolith material combined with classic gold nanoparticles, and erythrosine as the research object, by adjusting the different experimental conditions for optimal SERS enhancements, including system pH and mixing time, and ultimately selected theIn the present study, we developed a novel SERS substrate with the porous monolith material combined with classic gold nanoparticles, and erythrosine as the research object, by adjusting the different experimental conditions for optimal SERS enhancements, including system pH and mixing time, and ultimately selected the optimum pH value 506 and mixing time 25 min. Compared with the traditional gold plastic substrate enhancement effect, the experimental conditions were applied to the monolith substrate SERS detection of dye erythrosine, different concentrations of samples were used for erythrosine SERS detection, and the detection limit reached 01 g·mL-1. The method uses the payload of gold nanoparticles in mesoporous materials to effectively enhance the SERS signal. And this method has the advantages of simpleness and good stability, which provides a favorable theoretical basis for the rapid prohibited colorings screening..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 681 (2014)
Study of Fast Pretreatment Method in Detection of Melamine in Liquid Milk Using Liquid Chromatography and Raman Spectroscopy
LIU Feng, ZOU Ming-qiang, ZHANG Meng, ZHANG Xiao-fang, and LI Meng
The present paper proposed for the first time the flocculation-filtration method for separation of interfering substances in milk, such as fat. In this method only two steps were carried out. Firstly, aluminum chloride (PAC, Al2(OH)nCl6-n) is used to flocculate the milk; Secondly, water filter was used to filter the miThe present paper proposed for the first time the flocculation-filtration method for separation of interfering substances in milk, such as fat. In this method only two steps were carried out. Firstly, aluminum chloride (PAC, Al2(OH)nCl6-n) is used to flocculate the milk; Secondly, water filter was used to filter the mixture. Then the clear filtrate could be used for the detection of melamine. The whole preprocessing would not take more than one minute. The pretreatment process was optimized. Experiments show that the adding proportion of PAC should be about 2%～3% for best filtration efficiency, and that it would have the best flocculation effect when the mixture was mildly alkaline. High performance liquid chromatography experiments show that the melamine recovery of this method is more than 90%. Samples pretreated by the flocculation-filtration method were clearer and the baselines of spectral curve obtained by sensitizing Raman method were more smooth which means better purification compared to those samples pretreated by centrifugal pretreatment method. The pretreatment method proposed can be used in HPLC and Raman spectroscopy methods for rapid detecting melamine in liquid milk. This method shows better separation effect, simpler operation, and lower time and money cost than those pretreatment processes in the existing standard melamine detection method for milk. By use of this pretreatment method, the melamine rapid detection efficiency would be greatly improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 685 (2014)
Analysis of Three-Dimensional Fluorescence Overlapping Spectra Using Nonnegative Matrix Factorization
YU Xiao-ya, ZHANG Yu-jun, YIN Gao-fang, ZHAO Nan-jing, XIAO Xue, ZHANG Wei, ZHANG Rong, LU Chang-hua, and LIU Wen-qing
The present paper primarily tests and verifies the effect of NMF in blind source separation of three-dimensional simulative fluorescence spectra, and then four different computational algorithms (multiplicative iterative; alternating least square; second order method; projected gradient algorithm) were used in three prThe present paper primarily tests and verifies the effect of NMF in blind source separation of three-dimensional simulative fluorescence spectra, and then four different computational algorithms (multiplicative iterative; alternating least square; second order method; projected gradient algorithm) were used in three practical phenolic compounds(cresol, phenol, thymol) overlapping fluorescence spectra to find out which nonnegatively constrained algorithms is the most efficient for fluorescence spectra unmixing. The experiments demonstrate that four ways have the normalized residuals below 006%, and alternating least square(ALS) is the best at both convergence behavior and robustness..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 689 (2014)
3-D Fluorescence Properties of River with Great Flow Rate
XIE Chao-bo, WU Jing, CAO Zhi-ping, YANG Lin, QIAN Yi, Lv Qing, and ZHANG Ren-quan
In the present study, the three-dimensional fluorescence spectra of River A with great flow rate were investigated. The results showed that there existed three unambiguous peaks in the excitation-emission matrix of River A at λex/λem of around 230/340, 280/320 and 250/450 nm respectively. The fluorescence intensity varIn the present study, the three-dimensional fluorescence spectra of River A with great flow rate were investigated. The results showed that there existed three unambiguous peaks in the excitation-emission matrix of River A at λex/λem of around 230/340, 280/320 and 250/450 nm respectively. The fluorescence intensity varied significantly and had sharp fluctuation sometimes. But the CODMn of the samples remained quite stable. This study indicated that fluorescence technique could demonstrate the pollution in the water bodies with great flow rate and furthermore make up for the deficiency of the conventional parameters related to organic pollution, i. e. invalidation to exhibit the components of pollutants. It is a good tool for the early-warning of the water quality..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 695 (2014)
Optical Signatures of Chromophoric Dissolved Organic Matter in Water Body of Tien Lake
CHENG Qing-lin, ZHENG Bing-hui, WANG Sheng-rui, JIAO Li-xin, and HUANG Min-sheng
The water samples of the Tien Lake were collected for the three-dimensional fluorescence spectrum detected. And parallel factor analysis (PARAFAC) and principal component analysis (PCA) were used for the spectra analyzing to know the main factor and relative contribution of the chromophoric dissolved organic matter (CDThe water samples of the Tien Lake were collected for the three-dimensional fluorescence spectrum detected. And parallel factor analysis (PARAFAC) and principal component analysis (PCA) were used for the spectra analyzing to know the main factor and relative contribution of the chromophoric dissolved organic matter (CDOM). PARAFAC decomposed CDOM into four components, the humic-like: C1(240, 415), C3(265, 525), C4(255, 505) and the protein-like: C2(230/280, 330). The fluorescence intensity of CDOM components was high in north and estuary of the lake, but low in the other region. All the four components show significant positive correlations (p＜001), this result means they may have the same sources. Principal component analysis shows that these four components of the Tien Lake are all from terrestrial organic matter, meanwhile its DTN, DTP, DON may also come with the terrestrial substance. These components of Tien Lake can well be connected with dissolved nutrient salts by nonlinear multiple regression, which means we can use the three-dimensional fluorescence spectrum results of CDOM to indicate the eutrophication degree of Tien Lake..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 698 (2014)
Variation Characteristics and Removal Rate of Fluorescence Organic Matter in the Petrochemical Wastewater Treatment Process
ZHOU Jing-ling, XI Hong-bo, ZHOU Yue-xi, XU Ji-xian, and SONG Guang-qing
Petrochemical wastewater is of huge quantity released during the production and complicated contaminants of petrochemical wastewater will have immense negative impact on ecology environment Three-dimensional excitation-emission matrix fluorescence(3D-EEM) was used to investigate the characteristic fluorescence of inflPetrochemical wastewater is of huge quantity released during the production and complicated contaminants of petrochemical wastewater will have immense negative impact on ecology environment Three-dimensional excitation-emission matrix fluorescence(3D-EEM) was used to investigate the characteristic fluorescence of influent and effluent from each processing unit of Hydrolysis-acidification +A/O+ Contact-oxidation Process in a typical petrochemical wastewater treatment plant The results showed that there were 4 fluorescence peaks named Peak A, Peak B, Peak D, Peak E in the spectrum chart of influent, they are around λex/λem=220/300, 225/340, 270/300, 275/340 nm, the primary source of fluorescence organic matter(FOM) is industrial wastewater The fluorescence intensity of each fluorescence peak was decreased, while location was unchanged in the effluent of Hydrolysis-acidification Peak C appeared from the effluent of anaerobic tank at λex/λem=250/425 nm, then the fluorescence intensity of Peak C was enhanced in the effluent of aerobic tank Peak A disappeared from the effluent of secondary sedimentation tank The spectrum chart of the wastewater had no obvious variation after secondary sedimentation tank The removal rate of FOM was expressed with the degradation percentage of the fluorescence intensity, the total FOM was reduced by 920% after processing, and the removal rate of the FOM fluoresce around Peak A, Peak B, Peak D, Peak E were 1000%, 912%, 803%, 920% respectively A volatile IPeak B/IPeak E value of influent but a relatively stable value of effluent demonstrated that the wastewater treatment plant operated steadily and the process has higher capacity in resistance to shock loading.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 704 (2014)
The Research of UV-Responsive Sensitivity Enhancement of Fluorescent Coating Films by MgF2 Layer
LU Zhong-rong, NI Zheng-ji, TAO Chun-xian, HONG Rui-jin, ZHANG Da-wei, and HUANG Yuan-shen
A low cost and less complicated expansion approach of wavelength responses with a Lumogen phosphor coating was adopted, as they increased the quantum efficiency of CCD and CMOS detectors in ultra-violet by absorbing UV light and then re-emitting visible light. In this paper, the sensitivity enhancement of fluorescence A low cost and less complicated expansion approach of wavelength responses with a Lumogen phosphor coating was adopted, as they increased the quantum efficiency of CCD and CMOS detectors in ultra-violet by absorbing UV light and then re-emitting visible light. In this paper, the sensitivity enhancement of fluorescence coatings was studied by adding an anti-reflection film or barrier film to reduce the loss of the scattering and reflection on the incident interface. The Lumogen and MgF2/Lumogen film were deposited on quartz glasses by physical vacuum deposition. The surface morphology, transmittance spectrum, reflectance spectrum and fluorescence emission spectrum were obtained by atomic force microscope (AFM), spectrophotometer and fluorescence spectrometer, respectively. The results indicated that MgF2 film had obvious positive effect on reducing scattering and reflection loss in 500～700 nm, and enhancing the absorption of Lumogen coating in ultraviolet spectrum. Meanwhile, the fluorescent emission intensity had a substantial increase by smoothing the film surface and thus reducing the light scattering. At the same time, the MgF2 layer could protect Lumogen coating from damaging and contamination, which give a prolong lifetime of the UV- responsive CCD sensors with fluorescent coatings..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 709 (2014)
Study on the Vacuum Ultraviolet Transmittance of Barium Fluoride Crystals at Different Temperature
PENG Ru-yi, FU Li-ping, and TAO Ye
Two VUV-grade BaF2 windows with 05 mm-thick and 1 mm-thick respectively were selected to study the transmittance variety with the temperature. The results show that the cutoff wavelength of BaF2 crystals will shift towards the long wave with the increase in temperature. In a certain temperature range, BaF2 crystals caTwo VUV-grade BaF2 windows with 05 mm-thick and 1 mm-thick respectively were selected to study the transmittance variety with the temperature. The results show that the cutoff wavelength of BaF2 crystals will shift towards the long wave with the increase in temperature. In a certain temperature range, BaF2 crystals can depress 130.4nm radiation well, and also has a high transmittance at 1356 nm. Compared with the reported method in which SrF2 crystals can be applied to suppress 1304 nm stray light by heating, BaF2 crystal can inhibit the 1304 nm emission line completely, and thus reduce the power consumption of the device at the same time. This indicates that BaF2 crystals can play an important role in the ionosphere optical remote sensing detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 713 (2014)
The Nitrate and Temperature Impact Analysis in the Detection of COD by UV Spectrum
BI Wei-hong, LI Jian-guo, WU Guo-qing, FU Xing-hu, and FU Guang-wei
Configured standard solution of chemical oxygen demand with potassium hydrogen phthalate was used as experimental subjects, collected ultraviolet absorption spectra of the standard solution in the range of 1～800 mg·L-1, were collected, and PLS (partial least squares) algorithm was used to establish the correction Configured standard solution of chemical oxygen demand with potassium hydrogen phthalate was used as experimental subjects, collected ultraviolet absorption spectra of the standard solution in the range of 1～800 mg·L-1, were collected, and PLS (partial least squares) algorithm was used to establish the correction model of different spectral region,the results showed that. The model in the spectral region of 265～310 nm had the highest correlation and smallest error; In order to eliminate the impact of nitrates and temperature on the detection of the COD , studied the changes of the UV absorption spectrum with different concentrations of sodium standard solution and different temperature. The results showed that absorption of nitrate in 208～238 nm was apparent, and the model for spectral region of 265～310 nm was free from the influence of nitrate; In the full range of spectrum, temperature rising leads to an increase in absorbance, thus the temperature compensation model was established for the different spectral region through predictive analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 717 (2014)
Resonance Rayleigh Scattering Determination of Trace Ozone Based on the Cationic Surfactant Association Particles
LIU Gao-san, LIANG Ai-hui, WEN Gui-qing, and JIANG Zhi-liang
In the presence of pH 40 HAC-NaAC buffer solution, using H3BO3-KI (BKI) as absorption solution, O3 oxidized KI to produce I2, and it reacted with excess I- to form I-3 that combined with the cationic surfactant (CS) such as cetylpyridinium chloride (CPCl), tetradecyl pyridinium bromide (TPB), cetyl trimethyl ammonium In the presence of pH 40 HAC-NaAC buffer solution, using H3BO3-KI (BKI) as absorption solution, O3 oxidized KI to produce I2, and it reacted with excess I- to form I-3 that combined with the cationic surfactant (CS) such as cetylpyridinium chloride (CPCl), tetradecyl pyridinium bromide (TPB), cetyl trimethyl ammonium bromide (CTMAB), and tetradecyl dimethylbenzyl ammonium chloride (TDMAC) to produce stable (CS-I3)n association particles, which exhibited a strong resonance Rayleigh scattering (RRS) peak at 470 nm Under the chosen conditions, as the concentration of O3 (C) increased, the concentration of I-3 increased, and the RRS intensity at 470 nm (I470 nm) increased due to more association particles forming The increased RRS intensity I470 nm was linear with O3 concentration For the four CS systems, the linear range was 15～50, 50～100, 5～25 and 1～50 μmol·L-1 O3 respectively The regression equation is ΔI=881c-401, ΔI=544c-311, ΔI=1539c-155, and ΔI=1688c+051 The detection limit is 49, 12, 285 and 056 μmol·L-1 O3 respectively The influence of some foreign substances was examined on the determination of 25×10-6 mol·L-1 O3, within ±10% relative error Results showed that a 40×10-5 mol·L-1 Hg2+, 87×10-5 mol·L-1 Fe3+, 50×10-5 mol·L-1 Ca2+, 25×10-5 mol·L-1 Zn2+ and Cu2+, 28×10-6 mol·L-1 Pb2+ and Cr3+, 42×10-5 mol·L-1 Mg2+, Mn2+ and Ba2+ do not interfere with the RRS determination This showed that this RRS method is of good selectivity The TDMAC system is most sensitive, and was chosen to detect O3 in air samples The analytical results were in agreement with that of spectrophotometry results. Furthermore, laser scattering technique was utilized to examine the particle size distribution of (TDMAC-I3)n system Results indicated that the particle size located in the range of 190～531 nm, in the absence of O3 Upon addition of O3, the excess KI reacted with O3 to produce I-3, and I-3 interacted with the TDMAC to form (TDMAC-I3)n associated particles with a size range of 1 106～3 091 nm This test identified that there are associated particles in the TDMAC system.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 725 (2014)
A Quickly Atmospheric Correction Method for HJ-1 CCD with Deep Blue Algorithm
WANG Zhong-ting, WANG Hong-mei, LI Qing, ZHAO Shao-hua, LI Shen-shen, and CHEN Liang-fu
In the present, for the characteristic of HJ-1 CCD camera, after receiving aerosol optical depth (AOD) from deep blue algorithm which was developed by Hsu et al. assisted by MODerate-resolution imaging spectroradiometer (MODIS) surface reflectance database, bidirectional reflectance distribution function (BRDF) correctIn the present, for the characteristic of HJ-1 CCD camera, after receiving aerosol optical depth (AOD) from deep blue algorithm which was developed by Hsu et al. assisted by MODerate-resolution imaging spectroradiometer (MODIS) surface reflectance database, bidirectional reflectance distribution function (BRDF) correction with Kernel-Driven Model, and the calculation of viewing geometry with auxiliary data, a new atmospheric correction method of HJ-1 CCD was developed which can be used over vegetation, soil and so on. And, when the CCD data is processed to correct atmospheric influence, with look up table (LUT) and bilinear interpolation, atmospheric correction of HJ-1 CCD is completed quickly by grid calculation of atmospheric parameters and matrix operations of interface define language (IDL). The experiment over China North Plain on July 3rd, 2012 shows that by our method, the atmospheric influence was corrected well and quickly (one CCD image of 1 GB can be corrected in eight minutes), and the reflectance after correction over vegetation and soil was close to the spectrum of vegetation and soil. The comparison with MODIS reflectance product shows that for the advantage of high resolution, the corrected reflectance image of HJ-1 is finer than that of MODIS, and the correlation coefficient of the reflectance over typical surface is greater than 09. Error analysis shows that the recognition error of aerosol type leads to 005 absolute error of surface reflectance in near infrared band, which is larger than that in visual bands, and the 002 error of reflectance database leads to 001 absolute error of surface reflectance of atmospheric correction in green and red bands..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 729 (2014)
Effects of Aerosol Optical Thickness on the Optical Remote Sensing Imaging Quality
HU Xin-li, GU Xing-fa, YU Tao, ZHANG Zhou-wei, LI Juan, and LUAN Hai-jun
In recent years, due to changes in atmospheric environment, atmospheric aerosol affection on optical sensor imaging quality is increasingly considered by the load developed departments. Space-based remote sensing system imaging process, atmospheric aerosol makes optical sensor imaging quality deterioration. AtmosphericIn recent years, due to changes in atmospheric environment, atmospheric aerosol affection on optical sensor imaging quality is increasingly considered by the load developed departments. Space-based remote sensing system imaging process, atmospheric aerosol makes optical sensor imaging quality deterioration. Atmospheric medium causing image degradation is mainly forward light scattering effect caused by the aerosol turbid medium. Based on the turbid medium radiation transfer equation, the point spread function models were derived contained aerosol optical properties of atmosphere in order to analyze and evaluate the atmospheric blurring effect on optical sensor imaging system. It was found that atmospheric aerosol medium have effect on not only energy decay of atmospheric transmittance, but also the degradation of image quality due to the scattering effect. Increase of atmospheric aerosol optical thickness makes aerosol scattering intensity enhanced, variation of aerosol optical thickness is also strongly influences the point spread function of the spatial distribution. it is because the degradation of aerosol in spatial domain, which reduces the quality of remote sensing image, in particularly reduction of the sharpness of image. Meanwhile, it would provide a method to optimize and improve simulation of atmospheric chain..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 735 (2014)
A Method for Assessing the Total Viable Count of Fresh Meat Based on Hyperspectral Scattering Technique
SONG Yu-lin, PENG Yan-kun, GUO Hui, ZHANG Lei-lei, and ZHAO Juan
The objective of this study is to develop a hyperspectral imaging system to predict the bacteria total viable count in fresh pork. The hyperspectral scattering data were curvefitted by different fitting methods, and correlation differences of models were compared based on the bacteria total viable count of fresh pork, The objective of this study is to develop a hyperspectral imaging system to predict the bacteria total viable count in fresh pork. The hyperspectral scattering data were curvefitted by different fitting methods, and correlation differences of models were compared based on the bacteria total viable count of fresh pork, thus providing modeling basis of device for future study. Total 63 fresh pork samples which was used in the experiment were stored at 4 ℃ in the refrigerator of constant temperature. Experiment was performed everyday for 15 days. 4 or 5 random samples were used each day for the experiment. Hyperspectral scattering images and spectral scattering optical data in the wavelength region of 400 to 1 100 nm were acquired from the surface of all of the pork samples. Lorentz and Gompertz function and the modified function was applied to fit the scattering profiles of pork samples. Different parameters could be obtained by Lorentz and Gompertz fitting and the modified function fitting. The different parameters could represent the optical characteristic of the scattering profiles. The standard values of the bacteria total viable count of pork were obtained by classical microbiological plating methods. Because the standard value of the bacteria total viable count was big, log10 of the bacteria total viable count obtained by classical microbiological plating was used to simplify the calculation. Both individual parameters and integrated parameters were explored to develop the models. The multi-linear regression statistical approach was used to establish the models for predicting pork the bacteria total viable count. Both Lorentz and Gompertz function and the modified function included three and four parameters formula. The results showed that correlation coefficient of the models is higher with Lorentz three parameters combination, Lorentz four parameters combination and Gompertz four parameters combination than the individual parameters and other two or three integrated parameters. The three models’ correction set and prediction set correlation coefficients were 093, 096, 096 and 090, 090, 092, and the corresponding standard deviation were 047, 044, 039 and 056, 046, 042. Correlation was best with Gompertz four parameters. The device system will select the best correlation and the best stability of the model as the final model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 741 (2014)
Identification of Varieties of Black Bean Using Ground Based Hyperspectral Imaging
ZHANG Chu, LIU Fei, ZHANG Hai-liang, KONG Wen-wen, and HE Yong
In the present study, hyperspectral imaging combined with chemometrics was successfully proposed to identify different varieties of black bean. The varieties of black bean were defined based on the three different colors of the bean core. The hyperspectral images in the spectral range of 380~1 030 nm of black bean wereIn the present study, hyperspectral imaging combined with chemometrics was successfully proposed to identify different varieties of black bean. The varieties of black bean were defined based on the three different colors of the bean core. The hyperspectral images in the spectral range of 380~1 030 nm of black bean were acquired using the developed hyperspectral imaging system, and the reflectance spectra were extracted from the region of interest (ROI) in the images. The average spectrum of a ROI of the sample in the images was used to represent the spectrum of the sample and build classification models. In total, 180 spectra of 180 samples were extracted. The wavelengths from 440 to 943 nm were used for analysis after the removal of the spectral region with absolute noises, and 440~943 nm spectra were preprocessed by multiplicative scatter correction (MSC). Five classification methods, including partial least squares discriminant analysis (PLS-DA), soft independent modeling of class analogy (SIMCA), K-nearest neighbor algorithm (KNN), support vector machine (SVM) and extreme learning machine (ELM), were used to build discriminant models using the preprocessed full spectra, the feature information extracted by principal component analysis (PCA) and the feature information extracted by wavelet transform (WT) from the preprocessed spectra, respectively. Among all the classification models using the preprocessed full spectra, ELM models obtained the best performance; among all the classification models using the feature information extracted from the preprocessed spectra by PCA, ELM model also obtained the best classification accuracy; and among all the classification models using the feature information extracted from the preprocessed spectra by WT, ELM models obtained the best classification performance with 100% accuracy in both the calibration set and the prediction set. Among all classification models, WT-ELM model obtained the best classification accuracy. The overall results indicated that it was feasible to identify black bean varieties nondestructively by using hyperspectral imaging, and WT could effectively extract feature information from spectra and ELM algorithm was effective to build high performance classification models..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 746 (2014)
Estimation for Sparse Vegetation Information in Desertification Region Based on Tiangong-1 Hyperspectral Image
WU Jun-jun, GAO Zhi-hai, LI Zeng-yuan, WANG Hong-yan, PANG Yong, SUN Bin, LI Chang-long, LI Xu-zhi, and ZHANG Jiu-xing
In order to estimate the sparse vegetation information accurately in desertification region, taking southeast of Sunite Right Banner, Inner Mongolia, as the test site and Tiangong-1 hyperspectral image as the main data, sparse vegetation coverage and biomass were retrieved based on normalized difference vegetation indeIn order to estimate the sparse vegetation information accurately in desertification region, taking southeast of Sunite Right Banner, Inner Mongolia, as the test site and Tiangong-1 hyperspectral image as the main data, sparse vegetation coverage and biomass were retrieved based on normalized difference vegetation index(NDVI) and soil adjusted vegetation index(SAVI), combined with the field investigation data. Then the advantages and disadvantages between them were compared. Firstly, the correlation between vegetation indexes and vegetation coverage under different bands combination was analyzed, as well as the biomass. Secondly, the best bands combination was determined when the maximum correlation coefficient turned up between vegetation indexes (VI) and vegetation parameters. It showed that the maximum correlation coefficient between vegetation parameters and NDVI could reach as high as 07, while that of SAVI could nearly reach 08. The center wavelength of red band in the best bands combination for NDVI was 630nm, and that of the near infrared(NIR) band was 910 nm. Whereas, when the center wavelength was 620 and 920 nm respectively, they were the best combination for SAVI. Finally, the linear regression models were established to retrieve vegetation coverage and biomass based on Tiangong-1 VIs. R2 of all models was more than 05, while that of the model based on SAVI was higher than that based on NDVI, especially, the R2 of vegetation coverage retrieve model based on SAVI was as high as 059. By intersection validation, the standard errors RMSE based on SAVI models were lower than that of the model based on NDVI. The results showed that the abundant spectral information of Tiangong-1 hyperspectral image can reflect the actual vegetaion condition effectively, and SAVI can estimate the sparse vegetation information more accurately than NDVI in desertification region..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 751 (2014)
Progressive Damage Monitoring of Corrugated Composite Skins by the FBG Spectral Characteristics
ZHANG Yong, WANG Bang-feng, LU Ji-yun, GU Li-li, and SU Yong-gang
In the present paper, a method of monitoring progressive damage of composite structures by non-uniform fiber Bragg grating (FBG) reflection spectrum is proposed. Due to the finite element analysis of corrugated composite skins specimens, the failure process under tensile load and corresponding critical failure loads ofIn the present paper, a method of monitoring progressive damage of composite structures by non-uniform fiber Bragg grating (FBG) reflection spectrum is proposed. Due to the finite element analysis of corrugated composite skins specimens, the failure process under tensile load and corresponding critical failure loads of corrugated composite skin was predicated. Then, the non-uniform reflection spectrum of FBG sensor could be reconstructed and the corresponding relationship between layer failure order sequence of corrugated composite skin and FBG sensor reflection spectrums was acquired. A monitoring system based on FBG non-uniform reflection spectrum, which can be used to monitor progressive damage of corrugated composite skins, was built. The corrugated composite skins were stretched under this FBG non-uniform reflection spectrum monitoring system. The results indicate that real-time spectrums acquired by FBG non-uniform reflection spectrum monitoring system show the same trend with the reconstruction reflection spectrums. The maximum error between the corresponding failure and the predictive value is 8.6%, which proves the feasibility of using FBG sensor to monitor progressive damage of corrugated composite skin. In this method, the real-time changes in the FBG non-uniform reflection spectrum within the scope of failure were acquired through the way of monitoring and predicating, and at the same time, the progressive damage extent and layer failure sequence of corrugated composite skin was estimated, and without destroying the structure of the specimen, the method is easy and simple to operate. The measurement and transmission section of the system are completely composed of optical fiber, which provides new ideas and experimental reference for the field of dynamic monitoring of smart skin..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 757 (2014)
Modification on the Interaction of Glipizide with Bovine Serum Albumin by Molecular Spectroscopy
LIU Bao-sheng, CAO Shi-na, LI Zhi-yun, and CHONG Bao-hong
In the Tris-HCl buffer solution with pH was 740, the interaction between glipizide (Gli) and bovine serum albumin (BSA) was investigated by classical fluorescence spectroscopy with the change of protein as investigation object and elastic scattering fluorescence spectrometry with the change of drugs as investigation oIn the Tris-HCl buffer solution with pH was 740, the interaction between glipizide (Gli) and bovine serum albumin (BSA) was investigated by classical fluorescence spectroscopy with the change of protein as investigation object and elastic scattering fluorescence spectrometry with the change of drugs as investigation object at 293 K and 303 K, the conclusions of the two methods were consistent. Results showed that Gli could quench the intrinsic fluorescence of BSA, and the quenching mechanism was a dynamic quenching process. The hydrophobic force played an important role in the conjugation reaction between BSA and Gli, the binding site mainly located in BSA hydrophobic region and the number of binding site (n) in the binary system was approximately to 1. The values of Hill’s coefficients were less than 1, which indicated the weak negative cooperativity in BSA-Gli system. The binding constant (Ka) obtained by elastic scattering fluorescence spectrometric was much larger than the one obtained by classical fluorescence spectroscopy, indiciating that it was more accurate and reasonable when using the change of drug’s fluorescence as the research object. At last, the scientificalness of the new method based on elastic scattering fluorescence spectrometric was verified by ultraviolet spectroscopy. The research results showed that there existed insufficiency in analysis of the interaction of drug with protein by classical fluorescence spectroscopy with the change of protein as investigation object, and the fluorescence spectrogram only reflected partial information of the interaction between drug and protein, while the interaction between drug and protein could be better expressed by elastic scattering fluorescence spectrometry with the change of drugs as investigation object..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 762 (2014)
A Rapid Method for the Determination of Hydrogen Peroxide Concentration
ZHANG Qian, FU Shi-yu, LI Hai-long, and ZHAN Huai-yu
The present paper reported a spectrophotometry for the determination of hydrogen peroxide concentration. It is based on the reaction between ceric sulfate and hydrogen peroxide in an acidic medium, in which orange tetravalent cerium is converted to colorless trivalent cerium that causeds the change in absorbance. AccorThe present paper reported a spectrophotometry for the determination of hydrogen peroxide concentration. It is based on the reaction between ceric sulfate and hydrogen peroxide in an acidic medium, in which orange tetravalent cerium is converted to colorless trivalent cerium that causeds the change in absorbance. According to the quantitative relationship between ceric sulfate and hydrogen peroxide, the hydrogen peroxide concentration can be calculated. The selected conditions were as follows: detection wavelength of 480 nm, H2SO4 concentration of 05 mol·L-1, and reaction time of 30 min. The results showed that the method has an excellent measurement precision (RSD=0.31%) and accuracy (RSD≤0.91%) for the quantification of hydrogen peroxide. The present method is simple and rapid, with high detection sensitivity and low cost. It is suitable for use in rapid industrial analyses..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 767 (2014)
Study of Using Digital Photography to Measure Soil pH
WANG Kai-long, XIONG Hei-gang, and ZHANG Fang
Soil saline-alkalization is one of the most important problems of land degradation and the basic environmental problem in arid and semi-arid regions. The digital photography technology can rapidly and timely provide the information about properties, geographical distribution and extent of soil saline-alkalization. For Soil saline-alkalization is one of the most important problems of land degradation and the basic environmental problem in arid and semi-arid regions. The digital photography technology can rapidly and timely provide the information about properties, geographical distribution and extent of soil saline-alkalization. For verifying use digital photography assess degrees of sodality promptly and accurately, based on the monitored data of soil pH and measured VIS-NIR reflectance and photographs on given spots, The correlation were analyzed between soil pH and color space model parameters, Partial least squares Regression (PISR) was employed to build predicting model of pH value and the different between two Kinds of data were compared. The results showed that most of parameters with significant correlation While the CIEL*a*b* color model was the best. and it is the best model to assess soil pH(R2=0795, RMSECV=0084). Prediction set has also seen it was accurate and stability (R2=0781, RMSEP=0158). The prediction had no significant difference between the digital photography and VIS-NIR reflectance data. The digital image color analysis method showed the potential of being used in soil pH value assessing in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 771 (2014)
Study on Two Different Aromas Styles of Tobacco from Guizhou by Characteristics Spectroscopic Methods
RAN Xia, MU Lan, LIU Ren-xiang, CONG Hang, ZHANG Qing-min, and WANG Fang
This paper made use of three-dimensional fluorescence and ultraviolet-absorption spectrum to analyze the spectral characteristics of etroleum ether extract from Guizhou flue-cured tobacco and the overall characteristic spectral information of tobacco chemical substances were obtained. The three dimensional fluorescenceThis paper made use of three-dimensional fluorescence and ultraviolet-absorption spectrum to analyze the spectral characteristics of etroleum ether extract from Guizhou flue-cured tobacco and the overall characteristic spectral information of tobacco chemical substances were obtained. The three dimensional fluorescence and ultraviolet-visible absorption spectrum of each petroleum ether extract of flue-cured tobacco from different areas are generally similar, but their intensity is different. There have three characteristic peaks in three dimensional fluorescence spectra: Ⅰ: Ex/Em=297/326 nm, Ⅱ: Ex/Em=250/330 nm, Ⅲ: Ex/Em=225/336 nm respectively and meanwhile the order of these peaks intensity is Ⅰ>Ⅲ>Ⅱ. The ultraviolet-visible absorption spectrum in 300～300 nm range presents four characteristic absorption peaks, whose maximum absorption wavelength are 329, 419, 445 and 419 nm respectively. Meanwhile, in accord with the relative intensity of characteristic peaks, it is known that there exist differences in the relative contents of the total chemical substances obtained from different flavor styles of the flue-cured tobacco. The clustering analysis results of three-dimensional fluorescence intensity score (D) and intensity ratio (R) show that in a certain range of distance coefficient, the flue-cured tobacco from different regions in Guizhou can be clearly divided into two classes “mildly sweet ”and “alcohol sweet ”. The classification can be well achieved in the smaller distance coefficient according to the ratio cluster of fluorescence intensity instead of the score cluster of fluorescence intensity. The method of three-dimensional fluorescence was better than that of ultraviolet-visible spectrometry in the matter of the clustering characteristic..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 777 (2014)
Impacts of Different Alkaline Soil on Canopy Spectral Characteristics of Overlying Vegetation
JIA Ke-li, and ZHANG Jun-hua
The relationship between alkalinity and pH of the soil, reflectance spectra and red-edge parameters of the sunflower canopy in different growth periods under different alkalinity soil were analyzed, respectively. The results showed that the spectral reflectance of the sunflower canopy in different stage under differentThe relationship between alkalinity and pH of the soil, reflectance spectra and red-edge parameters of the sunflower canopy in different growth periods under different alkalinity soil were analyzed, respectively. The results showed that the spectral reflectance of the sunflower canopy in different stage under different alkalinity soil is the same as the spectral reflectance characters of the other greenery canopy. Along with the advancement of the sunflower growth period, sunflower canopy spectral reflectance increases gradually at different stages, the spectral reflectance is higher at flowering stage than 7-leaf stage and budding stage, and there exists a high reflection peak at 809nm at flowering period. At the same time, the spectral reflectance is affected by salinity-alkalinity stress at different stages, in the near infrared shortwave band, the spectral reflectance of the sunflower canopy in different stage increases with the decreases in soil alkalinity. When the derivatives are applied to determine the wavelength of the red-edge, there is a shift phenomenon of the red edge. The red edges were at 702～720 nm during every growth period of the sunflower. The “blue shift” phenomenon is also emerged for red edge position and red edge sloped with the increase in the soil alkalinity. Conversely, at the same growth periods, the red edge positions and red edge slope move to longer wave bands with the decrease in soil alkalinity. There is a “red shift” phenomenon before flowering period and “blue shift” phenomenon after flowering period for the red edge position and red edge slope of canopy spectrum at the same soil alkalinity. Respectively. The red edges at different growth stages of the sunflower show very significant positive correlation and quadratic polynomial to alkalinity and pH of the soil. Therefore, we thought used the red edge features of greenery could indicate the soil alkalization degree, it providing scientific basis for monitoring soil alkalization degree by remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 782 (2014)
Determination of Benzo(α)pyrene in Food with Microwave-Assisted Extraction
ZHOU Na, LUO He-dong, LI Na, and LI Yao-qun
Coupling derivative technique and constant-energy synchronous fluorescence scanning technique, a method of determining benzo［α］pyrene in foods by second derivative constant-energy synchronous spectrofluorimetry after microwave-assisted treatment of samples was established using domestic microwave oven. The main factorsCoupling derivative technique and constant-energy synchronous fluorescence scanning technique, a method of determining benzo［α］pyrene in foods by second derivative constant-energy synchronous spectrofluorimetry after microwave-assisted treatment of samples was established using domestic microwave oven. The main factors of influencing the efficiency of microwave extraction were discussed, including the extraction solvent types and amounts, the microwave extraction time, microwave radiation power and cooling time. And the comparison with ultrasonic extraction was made. Low-fat food samples, which were just microwave-extracted with mixed-solvents, could be analyzed immediately by the spectrofluorimetric technique. For high-fat food samples, microwave-assisted saponification and extraction were made at the same time, thus simplifying operation steps and reducing sample analysis time. So the whole sample analysis process could be completed within one hour. This method was simple, rapid and inexpensive. In consequence, it was applied to determine benzo(α)pyrene in food with good reproducibility and the recoveries of benzo(α)pyrene ranged from 900% to 1050% for the low fat samples and 833% to 946% for high-fat samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 787 (2014)
Study on the Choice of Functional Monomer before Preparation of Myclobutanil Molecularly Imprinted Polymer
GAO Wen-hui, LIU Bo, LI Xing-feng, HAN Jun-hua, and JIA Ying-min
To prepare myclobutanil molecularly imprinted polymer, a method was established for the choice of the appropriate functional monomer and its dosage. UV spectra was applied to study the combination form, the effect intensity, the optimal concentration ratio and the numbers of binding sites between myclobutanil and methyTo prepare myclobutanil molecularly imprinted polymer, a method was established for the choice of the appropriate functional monomer and its dosage. UV spectra was applied to study the combination form, the effect intensity, the optimal concentration ratio and the numbers of binding sites between myclobutanil and methyl acrylic acid (MAA) or acrylamide (AM) functional monomer. The results showed that hydrogen-bonding interaction could be formed between myclobutanil and methyl acrylic acid (MAA) or acrylamide (AM) functional monomer. The π electron of the triazole ring conjugated double bond in myclobutanil could transit to π* conjugate antibonding orbital when it absorbed energy. The formation of hydrogen bond could make π→π* absorption band transit. Maximum absorption wavelength produced red shift with the increase in the functional monomer concentration in the system. The research revealed that the optimal concentration ratios between myclobutanil and the two monomers were ｃ(M)∶ｃ(MAA)=1∶4, ｃ(M)∶ｃ(AM)=1∶2. Myclobutanil and the both the functional monomers had the bonding ability, and strong bonding force. The prepared molecularly imprinted polymer using AM as a functional monomer had better stability and specificity of recognition for myclobutanil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 791 (2014)
Research of Influence Factors on Spectral Recognition for Cotton Leaf Infected by Verticillium wilt
CHEN Bing, WANG Fang-yong, HAN Huan-yong, LIU Zheng, XIAO Chun-hua, and ZOU Nan
Through carrying out spectral test experiment, the influence factors of spectrum test were analyzed, the influence degree of various factors in spectral recognition was explicated and the method of spectra test was optimized for cotton leaf infected by verticillium wilt. The results indicated that under different severThrough carrying out spectral test experiment, the influence factors of spectrum test were analyzed, the influence degree of various factors in spectral recognition was explicated and the method of spectra test was optimized for cotton leaf infected by verticillium wilt. The results indicated that under different severity levels, the shape and value of reflectance of disease symptoms part were Significantly higher than healthy part on cotton leaf, compared with the black board as baseboard, the spectral values of disease leaves were slightly higher in visible light wavebands and significantly higher in others wavebands than healthy leaves on white baseboard. Different position of leaf on cotton plant has different effect degree to the recognition of disease, the effect of stem leaf was more obvious than that of else leaf, the identical leaf position was less influenced by disease than that of others. The effect of healthy leaf was smaller than disease leaf. The reflectance of leaf back was higher than front in visible light waveband, from high to flat, and then low in near infrared waveband, and from high to low to in short infrared waveband. Test time and cotton varieties had less influence on recognizing disease by spectra, and the effect of the same condition was acceptable. Test site had no effect on disease recognition by spectra. The effect of each factor was different for recognizing disease leaf by spectra, and this study will provide reference for the researchers of crop disease diagnosis by spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 795 (2014)
Preliminary Study of Atomic Emission Spectrometry of Ti(H) Plasma Produced by Vacuum Arc Ion Source
DENG Chun-feng, WU Chun-lei, WANG Yi-fu, LU Biao, and WEN Zhong-wei
In order to study the discharge process of vacuum arc ion source, make a detail description of the discharge plasma, and lay the foundation for further research on ion source, atomic emission spectrometry was used to diagnose the parameters of plasma produced by vaccum arc ion source. In the present paper, two kinds ofIn order to study the discharge process of vacuum arc ion source, make a detail description of the discharge plasma, and lay the foundation for further research on ion source, atomic emission spectrometry was used to diagnose the parameters of plasma produced by vaccum arc ion source. In the present paper, two kinds of analysis method for the emission spectra data collected by a spectrometer were developed. Those were based in the stark broadening of spectral lines and Saba-Boltzmann equation. Using those two methods, the electron temperature, electron number density and the ion temperature of the plasma can be determined. The emission spectroscopy data used in this paper was collected from the plasma produced by a vacuum arc ion source whose cathode was made by Ti material (which adsorbed hydrogen during storage procedure). Both of the two methods were used to diagnose the plasma parameters and judge the thermal motion state of the plasma. Otherwise, the validity of the diagnostic results by the two methods were analyzed and compared. In addition, the affection from laboratory background radiation during the spectral acquisition process was discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 801 (2014)
Time-Evolution Study on the Cation Exchange in the Process of Reinforcing Slip Soil by Laser-Induced Breakdown Spectroscopy
LIU Lu-wen, ZENG Wei-li, ZHU Xiang-fei, WU Jin-quan, and LIN Zhao-xiang
In the present paper, the time evolution study on slip soils treated by different proportions of ionic soil stabilizer (ISS) water solution was conducted by the LIBS system and the relationship between the cation exchange and such engineering properties of reinforcing soil as plasticity index, cohesive force and coeffiIn the present paper, the time evolution study on slip soils treated by different proportions of ionic soil stabilizer (ISS) water solution was conducted by the LIBS system and the relationship between the cation exchange and such engineering properties of reinforcing soil as plasticity index, cohesive force and coefficient of compressibility were analyzed. The results showed that the cation exchange velocity of the proportion of 1∶200 ISS reinforcing soil is the fastest among the three proportions (1∶100, 1∶200 and 1∶300) and the modification effect of engineering performance index is quite obvious. These studies provide an experimental basis for the ISS applied to curing project, and monitoring geotechnical engineering performance by LIBS technology also provides a new way of thinking for the curing project monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 805 (2014)
Determination of Si and P in MnZn Ferrites by Inductively Coupled Plasma Mass Spectrometry
ZHANG Ping, FU Liang, and NIE Xi-du
An inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of Si and P in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water then the above two elements in the solution were analyzed directly by ICP-MS. The analytical eAn inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of Si and P in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water then the above two elements in the solution were analyzed directly by ICP-MS. The analytical elements were by introducing the helium gas into the octopole reaction system (ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effects and the instrument drift could be commendably calibrated with Y as internal standard element. The working parameters of the instrument were optimized. The NIST SRM 362 and NIST SRM 364 were used as standard reference materials. The results showed a good agreement between the certified values and the experimental results for three analytes. The detection limits for Si and P is 091 and 027 μg·L-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 808 (2014)
Estimation of Soil’s Heavy Metal Concentrations(As,Cd and Zn) in Wansheng Mining Area with Geochemistry and Field Spectroscopy
SONG Lian, JIAN Ji, TAN De-jun, XIE Hong-bin, LUO Zhen-fu, and GAO Bo
In the present paper, Chongqing Wansheng mining area was selected as the study area, and the ASD FieldSpec Pro Ⅲ portable spectroradiometer (350 to 2 500 nm) was used as the spectral measurement instrument to collect the reflectance spectra of 171 soil samples and 123 soil samples in March and in August 2012 respectiveIn the present paper, Chongqing Wansheng mining area was selected as the study area, and the ASD FieldSpec Pro Ⅲ portable spectroradiometer (350 to 2 500 nm) was used as the spectral measurement instrument to collect the reflectance spectra of 171 soil samples and 123 soil samples in March and in August 2012 respectively. In order to create the retrieval model to retrieve soil heavy metal concentration, 40 among the 123 soil samples in august 2012 were collected to do chemical analysis. Then, the heavy metals’ concentration and the reflectance of the 40 soil samples were analyzed together. The results show that the ratio of the reflectance at 2 320 and 1 755 nm in the nearinfrared range, the ratio of the reflectance on 2 260 and 2 210 nm in the nearinfrared range, and the ratio of the reflectance at 480 and 1 920 nm in the visible and near infrared range has a significant correlation with heavy metal concentration of As, Cd and Zn respectively, so the spectral absorption feature parameters(SAFP) for retrieving soil heavy metal concentration of As, Cd and Zn from soil reflectance was created. Thus, the soil heavy metal concentration of As, Cd and Zn of the soil samples can be retrieved with the reflectance spectra. Then the distributions of the soil heavy metal concentration of As, Cd and Zn were obtained with the interpolation method in study area in March and in August 2012 respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 812 (2014)
Distribution and Speciation of Pb in Arabidopsis Thaliana Shoot and Rhizosphere Soil by In Situ Synchrotron Radiation Micro X-Ray Fluorescence and X-Ray Absorption Near Edge Structure
SHEN Ya-ting
In order to investigate plant reacting mechanism with heavy metal stress in organ and tissue level, synchrotron radiation micro X-ray fluorescence(μ-SRXRF) was used to determine element distribution characteristics of K, Ca, Mn, Fe, Cu, Zn, Pb in an Arabidopsis thaliana seedling grown in tailing dam soil taken from a lIn order to investigate plant reacting mechanism with heavy metal stress in organ and tissue level, synchrotron radiation micro X-ray fluorescence(μ-SRXRF) was used to determine element distribution characteristics of K, Ca, Mn, Fe, Cu, Zn, Pb in an Arabidopsis thaliana seedling grown in tailing dam soil taken from a lead-zinc mine exploration area The results showed a regular distribution characters of K, Ca, Fe, Cu and Zn, while Pb appeared not only in root, but also in a leaf bud which was beyond previously understanding that Pb mainly appeared in plant root Pb competed with Mn in the distribution of the whole seedling Pb may cause the increase of oxidative stress in root and leaf bud, and restrict Mn absorption and utilization which explained the phenomenon of seedling death in this tailing damp soil Speciation of Pb in Arabidopsis thaliana and tailing damp rhizosphere soil were also presented after using PbL3 micro X-ray absorption near edge structure(μ-XANES) By comparison of PbL3 XANES peak shape and peak position between standard samples and rhizosphere soil sample, it was demonstrated that the tailing damp soil was mainly formed by amorphous forms like PbO(642%), Pb(OH)2(288%) and Pb3O4(63%) rather than mineral or organic Pb speciations The low plant bioavailability of Pb demonstrated a further research focusing on Pb absorption and speciation conversion is needed, especially the role of dissolve organic matter in soil which may enhance Pb bioavailability.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 818 (2014)
Spectroscopic Analysis of the Decay Resistance of Wood Treated with Extracts from the Xylem of Cinnamomum Camphora with XRD and FTIR Approaches
LI Quan, WANG Xiao-xian, and LIN Jin-guo
Four kinds of extracts from the xylem of C. Camphora, ACQ and camphor were selected to make wood preservatives for laboratory toxicity test of wood preservatives for decay fungus. The results showed that the treated blocks with 4% ACQ and 10% methanol extracts could meet the demand of degree Ⅰ of preservation and showeFour kinds of extracts from the xylem of C. Camphora, ACQ and camphor were selected to make wood preservatives for laboratory toxicity test of wood preservatives for decay fungus. The results showed that the treated blocks with 4% ACQ and 10% methanol extracts could meet the demand of degree Ⅰ of preservation and showed strong resistance to brown-rot fungus attack. The wood treated with 4% camphor extracts, 10% ethyl acetate extracts, and 10% acetone extracts reached the demand of degree Ⅱ and showed moderate decay resistance. The blocks treated with 10% hot water extracts and untreated samples meet the demand of degree Ⅲ. Through XRD comparison, the author was found that the preservative effects of four extracts are proportional to the degree of crystallinity. Crystallization fields 2θ diffraction angle were ordered from larger to little as 10% hot water extracts＞untreated samples＞10% acetone extracts＞10% methanol extracts＞10% ethyl acetate extracts. According to FTIR analysis, the amount of degraded cellulose and hemicellulose increased with the decline of characteristic absorption peak at 1 374, 1 160, 1 106, 1 056 and 897 cm-1, meaning that the preservative effect of corresponding preservatives were getting worse. The peak height of characterization of lignin is higher compared to the untreated wood. I1 510/I1 738, I1 510/I1 374, I1 510/I1 160 of the treated blocks with 10% methanol extracts and 4% ACQ are the smallest in all the treated blocks, which proved that the degradation ability of brown-rot fungus to the holocellulose is the weakest, and the wood preservative is best..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 823 (2014)
Chemical Composition and Chromaticity Characteristic of Purple-Gold Glaze of Jingdezhen Imperial Kiln
WU Jun-ming, LI Qi-jiang, ZHANG Mao-lin, WU Juan, DING Yin-zhong, CAO Jian-wen, and LIU Xiao-jing
Color glaze is one of the four famous traditional ceramics of Jingdezhen, especially for the products from Ming and Qing Dynasties’ official kilns which have rich connotation of technology and culture. The chemical composition and chromaticity characteristic of glaze and body of purple-gold glaze samples from JingdezheColor glaze is one of the four famous traditional ceramics of Jingdezhen, especially for the products from Ming and Qing Dynasties’ official kilns which have rich connotation of technology and culture. The chemical composition and chromaticity characteristic of glaze and body of purple-gold glaze samples from Jingdezhen Ming and Qing Dynasties’ official kilns were analyzed by energy dispersive X ray fluorescence (EDXRF) and colorimeter. Preliminary study on the composition, formula and chromaticity characteristic of glaze of purple-gold glaze samples of different period was carried out and the intrinsic causes of differences were discussed. The result shows that the concentration of magnesium and calcium in purple-gold glaze is different from the other glazes in Jingdezhen in the same time, probably due to the addition of auburn or brown limestone which is rich in magnesium. The purple-gold glaze sample of Ming Dynasty is darker chiefly because the concentration of magnesium and calcium is higher than the sample of Ming Dynasty which led to iron crystal separated, reducing the brightness and glossiness of glaze. In addition, the body of purple-gold glaze samples from Jingdezhen Ming and Qing Dynasties’ official kilns has the characteristics of high silicon and low aluminum and the molar ratio of silicon to aluminum of samples from Ming Dynasty to Qing Dynasty declined, showing that the concentration of kaolin of sample’s body of Ming dynasty was increased. The result of this experiment fill deficiency in the ceramic science and technology research in our country about purple-gold glaze from Ming and Qing Dynasties’ official kilns and provides scientific material for comprehensive understanding of porcelain marking technology and intrinsic value of Jingdezhen official kiln..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 827 (2014)
Application of KPLSR Based on Line Index in Stellar Atmospheric Physical Parameter Measurement
WANG Jie, PAN Jing-chang, and TAN Xin
In the present paper, the kernel partial least squares regression (KPLSR) method was used to measure the atmospheric physical parameters (effective temperature, surface gravity, an d chemical abundance) based on the use of Lick line index. The proposed method can reduce the computation cost and achieve an ideal measureIn the present paper, the kernel partial least squares regression (KPLSR) method was used to measure the atmospheric physical parameters (effective temperature, surface gravity, an d chemical abundance) based on the use of Lick line index. The proposed method can reduce the computation cost and achieve an ideal measure precision. At first, the Lick indices of Kurucz synthetic spectra were extracted and the kernel regression model between the Lick indices and the atmospheric physical parameters was established using the KPLSR method. Then the physical parameters of DR8 measured spectral data were computed by the kernel regression model for testing. The test results were compared with the atmospheric physical parameters provided by SEGUE SSPP and were good results. In addition, we added a signal-to-noise ratio (SNR) of 10, 20, 30, 40, 50, 70, 90 and 120 Gaussian white noise to the Kurucz spectra. And the resulting spectra of different SNR were used to test the impact of noise on the parameter measurement. The experimental results show that the kernel regression model is sensitive to noise, the higher the SNR of spectral data, the higher the prediction accuracy of the physical parameters. The method of KPLSR based on Lick line index has small amount of computation and fast training speed, which is suitable for measuring physical parameters of stellar atmosphere..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 833 (2014)
Design of UV Annular Imaging System for Atmospheric Limb Detection
ZHANG Jing, WANG Shu-rong, LI Bo, XUE Qing-sheng, and HUANG Yu
In order to meet the requirements of imaging the surrounding 360°scene at one time without rotating the optical system and satisfy the UV limb detecting, a panoramic imaging system was presented for atmospheric UV limb detection. First, considering the special working band and innovative application and proceedingIn order to meet the requirements of imaging the surrounding 360°scene at one time without rotating the optical system and satisfy the UV limb detecting, a panoramic imaging system was presented for atmospheric UV limb detection. First, considering the special working band and innovative application and proceeding from the basic principle of traditional panoramic annular lens, the curvature radius of four spherical surfaces was adjusted, combined with the detector size so that can get the best MTF. Then, based on the aberration theory, the relay lens system was designed to make up the aberration produced by panoramic annular lens. The separation of positive and negative lens combination with different refraction and Abbe number was used. The negative lens used fused silica, while the positive lens used calcium fluoride, so to correct the apochromatism. Finally, the optical system was optimized with CODE-V and the important tolerance parameters were listed, so that the subsequent processing can be requested. The design results show that the diameter of 80% encircled energy of UV panoramic limb imaging system is below 11 μm, which is smaller than the pixel size of CCD, and the MTF value of the system is higher than 07@384 mm-1 over all fields. These data satisfy the requirements of the system and prove the feasibility of panoramic imaging system in atmospheric UV limb detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 843 (2014)
Coded Aperture Spectral Data Restoration Based on Two-Step Iterative Shrinkage/Threshold
LI Yun, HU Bing-liang, WANG Shuang, LI Ran, and SHI Da-lian
Coded aperture imaging spectrometer based on the concept of compressed sensing can acquire the spectral diagram of object. Coded aperture spectral data restoration reconstructs three-dimensional data cube from two-dimensional coded image. The two-step iterative shrinkage/thresholding algorithms were derived from the itCoded aperture imaging spectrometer based on the concept of compressed sensing can acquire the spectral diagram of object. Coded aperture spectral data restoration reconstructs three-dimensional data cube from two-dimensional coded image. The two-step iterative shrinkage/thresholding algorithms were derived from the iterative shrinkage threshold algorithm and weighted iterative shrinkage algorithm. Recovering coded aperture spectral data using the two-step iterative shrinkage/thresholding algorithms obtained the three-dimensional spectral data cube successfully..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 847 (2014)
Research of Spectrum Signal-to-Noise Ratio of Large Aperture Static Imaging Spectrometer
WANG Shuang, XIANGLI Bin, LI Li-bo, and PI Hai-feng
The process of acquiring hyperspectral data cube of a Large Aperture Static Imaging Spectrometer (LASIS) includes several vital and essential steps, such as interferometer modulation, rectangular convolution sampling by pixels of detector and spectra retrieving. In this process, how to precisely evaluate the Signal-NoiThe process of acquiring hyperspectral data cube of a Large Aperture Static Imaging Spectrometer (LASIS) includes several vital and essential steps, such as interferometer modulation, rectangular convolution sampling by pixels of detector and spectra retrieving. In this process, how to precisely evaluate the Signal-Noise Ratio (SNR) of spectra and how to wholly establish a related evaluation model were both generally very complicated. After a full consideration of the transmission process, utilizing the theory of rectangular convolution sampling and the spectral retrieving method regarding the computation of real part of the discrete Fourier transform of interferogram, formulas of both spectral signal and spectral noise were deduced theoretically, and then a evaluation model regarding the spectral SNR of LASIS was established. By using this model and other design factors of LASIS involving the wavenumber related optical transmittance, the interferometer beam splitter efficiency, the detector quantum efficiency and the main circuit noise, a simulation of spectral SNR was implemented. The simulation result was compared with the measurement result of the SNR of a LASIS instrument. The SNR lines and trends of the two match each other basically in single spectral band. The average deviation between them is proved to be 358%. This comparison result demonstrates the feasibility and effectiveness of the evaluation model. This SNR evaluation model consisting of the main technical aspects of typical LASIS instrument from the input spectral radiation to the output spectrum data is possible to be applied widely in practical design and implement of LASIS, as well as may provide valuable reference on SNR calculation and evaluation for other imaging spectrometers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 851 (2014)
[in Chinese]
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 857 (2014)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 1 (2014)
Research Articles
Study on Experiment of Absorption Spectroscopy Detection of Pesticide Residues of Carbendazim in Orange Juice
JI Ren-dong, CHEN Meng-lan, ZHAO Zhi-min, ZHU Xing-yue, WANG Le-xin, and LIU Quan-jin
Absorption spectra were studied for the carbendazim, in the mixed solution of orange juice and carbendazim using spectrophotometer. The most intensive characteristic peak (285 nm) was found in the spectrum of carbendazim standard solution. Compared with the carbendazim drug solution, the peak position of absorption speAbsorption spectra were studied for the carbendazim, in the mixed solution of orange juice and carbendazim using spectrophotometer. The most intensive characteristic peak (285 nm) was found in the spectrum of carbendazim standard solution. Compared with the carbendazim drug solution, the peak position of absorption spectrum has the blue shift(285～280 nm)when carbendazim(0.28 mg·mL-1)was added in the orange juice. So that we can conclude that interaction happened between the orange juice and carbendazim. Through the method of least squares fitting, the prediction models between the absorbance of orange juice and carbendazim content was obtained with a good linear relationship. The linear function model was: I=2.41 +9.26x, the correlation coefficient was 0.996, and the recovery was: 81%～102%. According to the regression model, we can obtain the amount of carbendazim pesticide residues in orange juice. It was verified that the method of using ultraviolet-visible absorption spectra was feasible to detect the carbendazim residues in orange juice. The result proved that it is possible to detect pesticide residues of carbendazim in orange juice, and it can meet the needs of rapid analysis. This study provides a new way for the detection of pesticide residues..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 721 (2014)
A Trace Gas Sensor Using Mid-Infrared Quantum Cascaded Laser at 48μm to Detect Carbon Monoxide
CHEN Chen, WANG Biao, LI Chun-guang, LI Jian, and WANG Yi-ding
Presented in the present paper is a compact instrument developed for rapid, sensitive and continuous monitoring of trace gases in air, with results shown for carbon monoxide concentration. This instrument takes advantage of recent technology in mid-infrared quantum cascaded laser (QCL) operating at 48 μm and mercury cPresented in the present paper is a compact instrument developed for rapid, sensitive and continuous monitoring of trace gases in air, with results shown for carbon monoxide concentration. This instrument takes advantage of recent technology in mid-infrared quantum cascaded laser (QCL) operating at 48 μm and mercury cadmium telluride (HgCdTe) mid-infrared (MIR) detector, combing MIR multipass herriott cell with 76 m absorption path length to obtain low detection sensitivity down to 50 nmol·mol-1 level in 4 s acquisition time. Meanwhile, in order to eliminate the instability induced by electrically modulated light source and effectively improve detection limit of the instrument, an optical structure with dual channel path was designed which is based on differential optical absorption spectroscopy method. The experimental results show that the instrument integrated with gas concentration inversion algorithm can be applied to in-situ measurements of trace gases without calibration. Additionally, operator could substitute a QCL operating at a different wavelength to measure other gases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 3, 838 (2014)
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