Journals >Spectroscopy and Spectral Analysis
Contents
2013
Volume: 33 Issue 2
64 Article(s)
Export citation format
Research Article
Organic Solar Cell Based On Alkylthiol/Au Self-assembly Film As Buffer Layer
XIE Xing, CHEN Zhi-jian, XIAO Li-xin, QU Bo, and GONG Qi-huang
The interface modification between the organic active layer and the inorganic electrode affects the performance of organic solar cell (OSC). A buffer layer of alkylthiol(ethanethiol, hexanethiol, dodecanethiol) /Au self-assembly layer was introduced into OSC to substitute Poly(3,4-ethylenedioxythiophene)∶poly(styrene sThe interface modification between the organic active layer and the inorganic electrode affects the performance of organic solar cell (OSC). A buffer layer of alkylthiol(ethanethiol, hexanethiol, dodecanethiol) /Au self-assembly layer was introduced into OSC to substitute Poly(3,4-ethylenedioxythiophene)∶poly(styrene sulfonate) (PEDOT∶PSS) layer, in order to improve the organic/inorganic interface. We fabricated devices with structure of “ITO/Au (annealed Au film of 2 nm)-thiol self assembly layer/ poly(3-hexylthiophene)∶1-(3-methoxycarbonyl) -propyl-1-phenyl-(6,6)C61(P3HT∶PCBM) /LiF/Al”. After alkanethiol self-assembling, the alkanethiol prevented exciton quenching owe to direct contact between the Au NPs and the active layer.We studied the impact of alkanethiol with different chain length on device performance. With?the?growth?of?the?alkyl chain, the coverage of the thiol on Au NPs got better, and the device performance become better. In the OSC with dodecanethiol /Au (2 nm Au film annealed) self-assembly film, the short-circuit current increases from 5.19 mA·cm-2 to 6.24 mA·cm-2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 289 (2013)
Growth and Red Luminescence Suppression of γ-CuⅠ Single Crystal
CAI Zu-xu, GU Mu, LIU Xiao-lin, LIU Bo, HUANG Shi-ming, and NI Chen
Transparent γ-CuⅠ crystal with size about 9 mm×9 mm×1 mm was grown by using optimized solvent evaporation method with γ-CuⅠ powders as raw material and acetonitrile as solvent. The results of Rutherford backscattering spectrometry (RBS) showed that the proportions of copper and iodine in as-grown γ-CuⅠ crystaTransparent γ-CuⅠ crystal with size about 9 mm×9 mm×1 mm was grown by using optimized solvent evaporation method with γ-CuⅠ powders as raw material and acetonitrile as solvent. The results of Rutherford backscattering spectrometry (RBS) showed that the proportions of copper and iodine in as-grown γ-CuⅠ crystal were 53.1 and 46.9mol%, respectively. By iodine doping into growth solution, the proportions of copper and iodine were adjusted to 50.4 and 49.6 mol%, respectively. Photoluminescence (PL) showed that the as-grown γ-CuⅠ crystal had an emission at 410 nm and an emission band around 720 nm. After iodine doping, the emission band around 720 nm was suppressed while other two weak emissions at 424 and 474 nm appeared. X-ray excited luminescence (XEL) showed that the as-grown γ-CuⅠ crystal had an emission at 435 nm and an emission band around 720 nm. After iodine doping, the emission band around 720 nm was suppressed. Comparing the emission spectra before and after iodine doping, it is clear that red luminescence in γ-CuⅠ crystal could be suppressed by iodine doping. The effect originated from the reduction of iodine vacancy in the crystal, but not from the iodine adsorbtion on the surface..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 293 (2013)
Numerical Simulation on HHG Spectra of Two-Electron H+3 Model
DAI Chun-yan, YU Chuan, ZHANG Gui-zhong, and YAO Jian-quan
The authors present a one-dimensional calculation model of H+3, and the time-dependent wavefunction was obtained by the symmetric split-operator method. The authors investigated the high-order harmonic generation (HHG) properties of H+3 model exposed to 800 nm-wavelength ultrashort laser pulse. The effect of electron iThe authors present a one-dimensional calculation model of H+3, and the time-dependent wavefunction was obtained by the symmetric split-operator method. The authors investigated the high-order harmonic generation (HHG) properties of H+3 model exposed to 800 nm-wavelength ultrashort laser pulse. The effect of electron interaction on the HHG spectra is less profound than at the cut-off frequency. We also calculated the HHG spectra for different internuclear separation values close to realistic one. Most of the calculated cutoff frequencies are beyond the three-step model’s prediction, and a preliminary scenario is suggested..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 297 (2013)
Vibrational and Rotational Spectrum of Carbon Monoxide at High Temperature
QI Xin-hua, SU Tie, YANG Fu-rong, BAO Wei-yi, and CHEN Li
The total partition function was calculated for carbon monoxide with approximation. Using the dipole moment function and the wave function with Morse approximation, we computed the matrix elements of vibrational-rotational transition and absorption coefficient at normal and high temperature. The computed results agreedThe total partition function was calculated for carbon monoxide with approximation. Using the dipole moment function and the wave function with Morse approximation, we computed the matrix elements of vibrational-rotational transition and absorption coefficient at normal and high temperature. The computed results agreed with the HITRAN database and literature, which shows that the calculation of total partition function and matrix elements of vibrational-rotational transition is reliable. Furthermore, the absorption coefficient and radiant spectrum are also presented at higher temperature of 4 000 and 6 000 K..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 300 (2013)
Theoretical Study on Geometrical Structure and Spectrum of 4-(2-Nitrobenzylideneamino)Phenyl Ethanone Schiff Base
LIANG Xiao-rui, JIANG Yan-lan, ZHANG Jing, QU Cheng-li, WANG Gang, WANG Xiu-juan, and ZHAO Bo
The UV absorption spectra, fluorescence emission spectra and fluorescence quantum yield of the title Schiff base were studied by experiment. The results showed that this compound displayed superior fluorescence properties. Geometrical optimization of the title compound was carried out by employing density functional thThe UV absorption spectra, fluorescence emission spectra and fluorescence quantum yield of the title Schiff base were studied by experiment. The results showed that this compound displayed superior fluorescence properties. Geometrical optimization of the title compound was carried out by employing density functional theory (DFT) method at the B3LYP/6-311G(d) level. The calculation results indicated that the title compound has comparatively stronger aromaticity and larger conjugate system. For the optimal configuration, there is no imaginary frequency after vibrational analysis, which indicates that the structure is stable. Based on the optimized structure for the ground state time-dependent density functional theory (TD-DFT) calculations were carried out at the B3LYP/6-311G level to predict the absorption spectra. The single-excitation configuration interaction (CIS) method was used to optimize the structure of the first excited state, and then TD-DFT calculations were carried out to predict the emission spectra. The results indicated that the wavelengths of the absorption and emission spectra are consistent with the experimental data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 304 (2013)
Experimental Investigation of Electrical Characteristics and Vibrational Temperature of Barrier Discharge in Flowing Argon
LI Xue-chen, LIU Run-fu, CHANG Yuan-yuan, and ZHAO Huan-huan
The electrical characteristics and vibrational temperature were investigated as functions of gas gap width, driving frequency and gas flow rate in flowing argon by using a dielectric barrier discharge device with transparent water electrodes. Electrical measurement results show that the discharge with a smaller gas gapThe electrical characteristics and vibrational temperature were investigated as functions of gas gap width, driving frequency and gas flow rate in flowing argon by using a dielectric barrier discharge device with transparent water electrodes. Electrical measurement results show that the discharge with a smaller gas gap width has a higher value of peak current and consumes more power than that with a larger gap width. Both the peak value of discharge current and consumed power increase monotonically with increasing the driving frequency, and decrease with increasing the gas flow rate. Through analyzing the vibrational systems of nitrogen molecule by optical emission spectroscopy, it was found that the vibrational temperature has a similar trend with the peak value of discharge current and consumed power by changing the driving frequency, gas gap width and gas flow rate. These results are important to the industrial applications of atmospheric pressure barrier discharge in flowing gas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 308 (2013)
Accurate Calculation of Spectral Line Profiles by Considering Influence of Varying Pressure and Temperature in a Gas
CHEN Zhou, TAO Shao-hua, DU Xiang-jun, and HOU Xiao-jing
Accurate calculation of spectral line profiles of a gas is very important for gas sensing. As we know, a variation in pressure (temperature) of a gas will result in the corresponding variation in temperature (pressure) of the gas. In the present paper we calculated spectral line profiles of a gas by considering the chaAccurate calculation of spectral line profiles of a gas is very important for gas sensing. As we know, a variation in pressure (temperature) of a gas will result in the corresponding variation in temperature (pressure) of the gas. In the present paper we calculated spectral line profiles of a gas by considering the changes in both temperature and pressure. The authors found that in our case the Lorentzian profile has broader applicable ranges of pressure and temperature, and the Gaussian profile is only applicable in some extreme conditions. Furthermore, the authors found that the influence of variations in pressure and temperature has to be considered in calculating the peak values of the spectral line profiles such as Gaussian, Lorentzian, and Voigt; otherwise the resultant relative errors of the calculated peak values can exceed 0.1. The similar observations were also found for other gases such as CH4, CO2, CO, and NO, although the parameters such as wavelength, coefficient of pressure-broadening, relative molecular mass, and temperature were different..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 312 (2013)
Multi-Spectral Thermometry Based on Radiation Measurement within a Finite Solid-Angle
XIN Cheng-yun, CHENG Xiao-fang, and ZHANG Zhong-zheng
Based on Planck’s law, the surface temperature of an object can be determined by measurement of emitted radiation. The equation for monochromatic radiation thermometry within a finite solid-angle was deduced, and it was found that if the surface temperature and spectral emissivity can be solved at the same time, the spBased on Planck’s law, the surface temperature of an object can be determined by measurement of emitted radiation. The equation for monochromatic radiation thermometry within a finite solid-angle was deduced, and it was found that if the surface temperature and spectral emissivity can be solved at the same time, the specific radiation measurement conditions for multi-spectral thermometry should be generally met that the radiation measurement should be implemented within an infinitesimal solid-angle or within a finite solid-angle only for a perfect diffuser. When the directional spectral emissivity modeled by finite polynomial series is employed and proper mathematical transformation is used, a universal equation for monochromatic radiation thermometry is obtained. So the restrictions in radiation measurement can be got rid of, but spectral emissivity may not be solved simultaneously. Multi-solution problem was preliminarily investigated, and so a solution was put forward that the channel number should be more than the number of the variables to be solved and the nonlinear least squares method should be used..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 316 (2013)
Synthsis and Photoluminescence Properties of Low-Tg Photorefractive Polymers of Double Founction
QU Yu-feng, FANG Yu, XU Liang, SUN Lian-lai, YANG Rui-zhuang, LUO Xuan, CAO Lin-hong, LIU Hong-jie, HUANG Jin, and JIANG Xiao-dong
A group of low-Tg photorefractive polymers of double function with carbazole and p-nitrodiazencarbazole called P-2, P-3 and P-4 were synthesized by means of different proportional diazonium salts being diazo-coupled with the poly ［bis(6-carbazolhexyloxy)］ phosphazene(P-1). P-2, P-3 and P-4 were characterized by 31P NMRA group of low-Tg photorefractive polymers of double function with carbazole and p-nitrodiazencarbazole called P-2, P-3 and P-4 were synthesized by means of different proportional diazonium salts being diazo-coupled with the poly ［bis(6-carbazolhexyloxy)］ phosphazene(P-1). P-2, P-3 and P-4 were characterized by 31P NMR, 1H NMR, IR, UV-Vis, GPC, TG and DSC. The result showed that P-2, P-3 and P-4 have good heat stability (Td≈300 ℃) and a lower glass transition temperature (Tg≈30~40 ℃). Their fluorescence properties were studied by photoluminescence and the result showed that P-1 has a stronger fluorescence properties and fluorescence intensity. P-2, P-3 and P-4 have varying degrees of quenching after nitro joining. The fluorescence properties were related with numbers of carbazole and nitro and their molecular space structure..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 320 (2013)
Synthesis and Upconversion Luminescence Properties of BaIn6Y2O13∶Yb3+, Er3+
YANG Yan-min, JIAO Fu-yun, LI Zi-qiang, SU Xian-yuan, ZHANG Shao-yang, SU Hong-xin, and LI Zhi-qiang
BaIn6Y2O13 phosphors with different doping concentrations of Yb3+ and Er3+ were prepared via the high temperature solid-state reaction method. XRD data showed that BaIn6Y2O13 phosphors belong to hexagonal system and the introduction of doping agent Yb3+ and Er3+ did not change the lattice structure of the host. The upcBaIn6Y2O13 phosphors with different doping concentrations of Yb3+ and Er3+ were prepared via the high temperature solid-state reaction method. XRD data showed that BaIn6Y2O13 phosphors belong to hexagonal system and the introduction of doping agent Yb3+ and Er3+ did not change the lattice structure of the host. The upconversion emission spectrum and power were measured by 971 nm LD laser with different excitation powers and the energy efficiencies of the samples were calculated. The obtained data showed that the ratio of green power to red power kept decreasing with the increase in doping agent concentration when the excitation density remains constant, increasing with the increase in the excitation density at the same concentration of doping agent. The analyses revealed that the former was attributed to the increasing cross relaxation between Er3+ ions, while the latter came from the raise of the energy transfer between Yb3+ and Er3+ ions and the excited state absorption of Er3+ ions due to the higher excitation density. With the increase in the excitation density, at the beginning the green luminescence power was proportional to the square of the excitation power, which agrees with the reported result. The maximum values of the fluorescence efficiencies of the samples were obtained as 0.38% (the doping concentrations of Yb3+ and Er3+ are 3%, 1%)and 0.06%(the doping concentrations of Yb3+ and Er3+ are 9%, 3%). It can be attributed to the long lifetime of 4I13/2 energy level so it can gather a large number of electrons and reduce the population of ground state, resulting in lower pump efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 325 (2013)
Study on Cephalosporins with Terahertz Time-Domain Spectroscopy Technique
ZHANG Man, ZHU Si-yuan, LI Qing-mei, and SHEN Jing-ling
Terahertz Time-Domain Spectroscopy (THz-TDS) technique has a wide range of applications in substances identification and quantitative analysis. In the present paper, we report absorption spectra and index of refraction of 14 kinds of pure cephalosporins in 0.2～2.6 THz, in which eight kinds have apparent absorption peakTerahertz Time-Domain Spectroscopy (THz-TDS) technique has a wide range of applications in substances identification and quantitative analysis. In the present paper, we report absorption spectra and index of refraction of 14 kinds of pure cephalosporins in 0.2～2.6 THz, in which eight kinds have apparent absorption peaks, while the others have different index of refraction. Based on these results, different kinds of antibiotics can be identified. Besides, according to THz absorption spectra of both pure sample and real pills we calculated the contents of cefixime in the two pills produced by two manufacturers. Compared with the contents marked on the package, relative errors are 9.38% and 0.92%, respectively. The results manifest that THz-TDS technique is reliable and promising in medicine detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 330 (2013)
Spectral Baseline Correction by Piecewise Dividing in Fourier Transform Infrared Gas Analysis
TANG Xiao-jun, WANG Jin, ZHANG Lei, GUAN Jin-feng, ZHANG Yong, and LIU Jun-hua
Aimed at the problem that baseline drift or distortion often appears in Fourier transform spectra after spectrometer has continuously worked for a long time, baseline variation caused by IR source temperature drift and fluctuation, tilt of moving mirror, performance parameter change of beam splitter and lateral shift oAimed at the problem that baseline drift or distortion often appears in Fourier transform spectra after spectrometer has continuously worked for a long time, baseline variation caused by IR source temperature drift and fluctuation, tilt of moving mirror, performance parameter change of beam splitter and lateral shift of detector were studied by simulating using MATLAB. Simulation results show that spectral baseline drift is approximately linear. On this basis, a novel method named spectral baseline correction by piecewise dividing (SBCPD) is proposed to correct spectral baseline in the present work. By comparing peak height of simulated spectra, it was found that performance of SBCPD is better than that of common methods of polynomial fitting, airPLS (adaptive iteratively reweighted Penalized Least Squares). And the application in gas well-logging showed that prediction accuracy of SBCPD is also higher. Additionally, this method is reliable and of less calculation, and is suitable for engineering application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 334 (2013)
Infrared Spectroscopic Study on Leaf Senescence of Evergreen Tree
LI Lun, ZHOU Xiang-ping, LIU Gang, ZHANG Li, OU Quan-hong, and HAO Jian-ming
In order to investigate plant physiological process of leaf senescence and aging, Fourier transform infrared (FTIR) spectroscopy was used to study the young, mature, and old yellow leaves from seven species of evergreen trees. The spectra of the leaves from different growing period are different in the region of 1 800～In order to investigate plant physiological process of leaf senescence and aging, Fourier transform infrared (FTIR) spectroscopy was used to study the young, mature, and old yellow leaves from seven species of evergreen trees. The spectra of the leaves from different growing period are different in the region of 1 800～700 cm-1. The absorption ratios A1 070/A2 927, A1 070/A1 160 were used to evaluate the relative changes of polysaccharides, and A1 318/A2 922 was used to estimate the change of calcium oxalate during leaf senescence. Decomposition and curve-fitting analysis was performed in the region of 1 800～1 500 cm-1. The sub-band absorption ratio H1 650/H1 740 was used to evaluate the relative changes of protein in the leaves. The results show that the accumulation and mobilization of polysaccharides, protein, and calcium oxalate during leaf growing period were different in different plant species. This study demonstrates the potential of mid-infrared spectroscopy for investigation of plants senescence, as well as physiological and biochemical changes of plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 340 (2013)
Diagnosis of Endometrial Cancer Based on Logistic Regression and Near Infrared Spectroscopy
ZHANG Jia-jin, ZHANG Zhuo-yong, XIANG Yu-hong, and YANG Fan
Endometrial carcinoma is one of the most common gynecologic cancers. The present paper reports a new application of Logistic regression to building model of endometrial cancer. Near infrared (NIR) spectra was introduced. In our study, the NIR spectra of 77 specimens were pretreated by principal component-linear discrimEndometrial carcinoma is one of the most common gynecologic cancers. The present paper reports a new application of Logistic regression to building model of endometrial cancer. Near infrared (NIR) spectra was introduced. In our study, the NIR spectra of 77 specimens were pretreated by principal component-linear discriminant analysis (PC-LDA) and support vector machine discriminant analysis (SVM-DA). Latin partition method for selecting training and test sets was used to determine the significant parameters for Logistic regression model. From the predicted results of logistic regression model, both the categories of samples and the trends of samples belonging to other class were clear and concordant with the clinical result. The proposed procedure proved to be suitable to being developed as a noninvasive diagnosis method for cancer tissue..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 344 (2013)
Study on the Application of Empirical Mode Decomposition to Noninvasive Hemoglobin Measurement by NIRS
FAN Yi-chen, LU Qi-peng, DING Hai-quan, GAO Hong-zhi, and CHEN Xing-dan
To increase the signal-to-noise ratio (SNR) of human near infrared (NIR) spectra, so as to improve the stability and precision of calibration model, the empirical mode decomposition (EMD) method was applied. Eighty-one fingertip absorption curves were collected, with the corresponding clinical examination results obtaiTo increase the signal-to-noise ratio (SNR) of human near infrared (NIR) spectra, so as to improve the stability and precision of calibration model, the empirical mode decomposition (EMD) method was applied. Eighty-one fingertip absorption curves were collected, with the corresponding clinical examination results obtained immediately. By means of outliers detection and removal, finally 78 samples were determined as the research objects. A three-layer back-propagation artificial neutron network (BP-ANN) model was established and worked for prediction. The results turned out that, through EMD method, the prediction correlation coefficient increased greatly from 0.74 to 0.87. RMSEP was reduced from 12.85 to 8.08 g·L-1. Other indexes were also obviously improved. The overall results sufficiently demonstrate that it is feasible to use EMD method for high SNR pulse wave signals, thus improving the performance of noninvasive hemoglobin calibration models. The application of EMD method can help promote the development of noninvasive hemoglobin monitoring technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 349 (2013)
Initial Research on FTIR Spectroscopy of Lyophilized Serum from Colorectal Cancer Patients
RUAN Sen-lin, WANG Ru, CHEN Xiao-yan, WU Ya-ying, LIU Qing, LIU Min, RAO Cui, and DENG Hong
In the present paper, lyophilized sera from 31 patients with colorectal cancer, 8 patients with enteritis and 10 healthy controls were measured using Nicolet Nexus-670 Fourier Transform Infrared (FTIR) spectrometer, and the spectral features were investigated and comparison among three groups was made. The result showeIn the present paper, lyophilized sera from 31 patients with colorectal cancer, 8 patients with enteritis and 10 healthy controls were measured using Nicolet Nexus-670 Fourier Transform Infrared (FTIR) spectrometer, and the spectral features were investigated and comparison among three groups was made. The result showed that (1) there are 11 peaks of absorption in the spectrum of lyophilized sera, the wavenumber of the ninth peak moved to 1 249 cm-1 in the colorectal cancer group and significant difference was observed with the control group (Z=-2.051, P<0.05); Five ratios of absorbance were calculated and no significant difference was observed among three groups; (2) spectrum in the region of 1 700～1 000 cm-1 was analysed with the method of hierarchical cluster analysis and showed only partial success in distinguishing the three groups; (2) spectrum of amide Ⅰ peptide (1 700～1 600 cm-1) was deconvolved to get the percentage composition of protein secondary structures, and no significant difference was observed among three groups. The results provide a preliminary theoretical basic for using FTIR spectrum of lyophilized serum for the early diagnosis of colorectal cancer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 354 (2013)
Pretreatment Method of Near-Infrared Diffuse Reflection Spectra Used for Sugar Content Prediction of Pears
WANG Wei-ming, DONG Da-ming, ZHENG Wen-gang, ZHAO Xian-de, JIAO Lei-zi, and WANG Ming-fei
The content of sugar is an important quality index for pears. However, the traditional sugar measurement methods are time-consuming and destructive. In the present study, the authors measured the sugar content of pears using visible and near infrared diffuse reflection spectroscopy. The pretreatment methods of multipliThe content of sugar is an important quality index for pears. However, the traditional sugar measurement methods are time-consuming and destructive. In the present study, the authors measured the sugar content of pears using visible and near infrared diffuse reflection spectroscopy. The pretreatment methods of multiplicative scatter correction (MSC), baseline correction, standard normal variate (SNV) transformation, and moving average algorithms were used on the original absorbance spectrum. Results indicate that the absorbance spectra after pretreatment are better than the original absorbance spectra for prediction. Partial least squares (PLS) regression was also used on the original absorbance spectrum and the absorbance spectrum after moving average and baseline correction. It follows that the forecast accuracy of the absorbance spectra after moving average is higher than that of the original absorbance spectra. The models gave good predictions of the sugar content of pears, with corresponding r values of 0.990 8, and standard errors of predictions of 0.019 0..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 359 (2013)
Application of Grey Correlation Analysis with Support Vector Machine in Near-Infrared Spectroscopy
ZHANG Yong, and ZHAO Bing
The foundation of grey relational analysis is to clarify the primary and secondary relationship among different factors in the system through calculating correlation degree, and find out the influential factors. In the present study, the near-infrared spectra of 180 tobacco samples were determined. Among them, 120 sampThe foundation of grey relational analysis is to clarify the primary and secondary relationship among different factors in the system through calculating correlation degree, and find out the influential factors. In the present study, the near-infrared spectra of 180 tobacco samples were determined. Among them, 120 samples were used for modeling and 60 samples were used for model checking. Then the quantitative analysis models of the tobacco samples, corresponding to total sugar, reducing sugar, nicotine and total nitrogen, were established using the partial least squares method and radial basis of support vector machine method. The experimental results show that, the grey correlation analysis with support vector machine method was used in the quantitative analysis of four tobacco components by near infrared spectroscopy, the generalization ability of the models and the prediction precision are obviously improved, which can effectively enhance the modeling efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 363 (2013)
FTIR-Based Vehicles Paint Comparison
CHEN Tao, LONG Xian-jun, WEI Lang, GONG Biao, and LI Chun-ming
In order to determine a range on vehicle types by the vehicle paints left on the accident site, 940 infrared spectra of vehicle paint from 287 vehicle samples were collected, and then the infrared spectrum database on vehicle body paint was established. The vehicle paints comparison was implemented by characteristic peIn order to determine a range on vehicle types by the vehicle paints left on the accident site, 940 infrared spectra of vehicle paint from 287 vehicle samples were collected, and then the infrared spectrum database on vehicle body paint was established. The vehicle paints comparison was implemented by characteristic peaks method and correlation coefficient method, and the comparison tests on different vehicle scrap paints were carried out. The test results show that the key of vehicle paint comparison is the spectrum of topcoat layer and the coating layer for the integrated scrap paint, and spectrum should be searched after layer separating for partial scrap paint. For aging paint, topcoat layer spectrum should be main emphasis and the range of suspect vehicle should be extended..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 367 (2013)
Discrimination of Eleven Genera of Chinese Herbs in Geraniaceae by FTIR Spectroscopy and Clustering Analysis
SUN Ren-shuang, JIN Zhe-xiong, ZHANG Zhe-peng, XU Chang-hua, ZHOU Qun, and SUN Su-qin
A fast identification method of eleven genera of Chinese herbs in geraniaceae was developed by the combination of Fourier transform infrared spectroscopy with clustering analysis. FTIR spectroscopy was employed to identify and analyze eleven genera of Chinese herbs in geraniaceae. On the basis of a principal component A fast identification method of eleven genera of Chinese herbs in geraniaceae was developed by the combination of Fourier transform infrared spectroscopy with clustering analysis. FTIR spectroscopy was employed to identify and analyze eleven genera of Chinese herbs in geraniaceae. On the basis of a principal component analysis (PCA) model, three genera of Chinese herbs were rapidly classified by using the method of SIMCA clustering analysis. These samples could be successfully classified by SIMCA. Recognition rate and rejection rate reached up to 98%. The accuracy of clustering reached up to 91% during blind sample testing. It is concluded that in combination with clustering analysis, FTIR method provides an effective way to rapidly evaluate Chinese herbs in Geraniaceae..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 371 (2013)
Gauss-Lorentz Quantitative Research on O—H Stretching Raman Spectra of Water in Common Chlorine Salt Solution
YANG Dan, and XU Wen-yi
In order to explore the Raman spectroscopy quantitative method of common cations in geological fluids, the present paper has systematically studied Raman spectra of NaCl-H2O, CaCl2-H2O, MgCl2-H2O, CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O solutions by Gauss-Lorentz deconvolution integrated peaks. The results shows that: (１)thIn order to explore the Raman spectroscopy quantitative method of common cations in geological fluids, the present paper has systematically studied Raman spectra of NaCl-H2O, CaCl2-H2O, MgCl2-H2O, CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O solutions by Gauss-Lorentz deconvolution integrated peaks. The results shows that: (１)there is a good quantitative relationship between the peak intensity ratio(low-frequency/ high frequency) and the concentration for all systems studied, and this result provides a convenient and reliable quantitative method for quantitative analysis of these systems at room temperature. (２)In the NaCl-H2O and CaCl2-H2O and MgCl2-H2O system, with the concentration increasing, the peak intensity ratio (LF/HF) shows a declining trend , and this result suggests that the number of intermolecular hydrogen bonds is gradually reduced; however, in the CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O system, the trend is on the rise; and this result suggests that the number of intermolecular hydrogen bonds is gradually increased; Such a result may be related to the complex that the transition metal ions formed in these three systems , and further studies are needed. (３)It can be seen through the slopes (that are obtained from fitting curves of the intensity ratio and the concentration in all systems) that the ability affecting of hydrogen bond of water molecules is in such order: CaCl2, MgCl2＞NaCl, FeCl3＞ZnCl2, CuCl2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 376 (2013)
Baseline Correction of Raman Spectrum Based on Piecewise Linear Fitting
QIN Zhao-jun, TAO Zhan-hua, LIU Jun-xian, and WANG Gui-wen
The baseline drifts of Raman spectra occur in many types of instrumental measurements. It is an important part and a routine step to correct the baseline drift for the data preprocessing. In the present work, the limitations of the baseline correction method based on polynomial fitting were highlighted and a modified pThe baseline drifts of Raman spectra occur in many types of instrumental measurements. It is an important part and a routine step to correct the baseline drift for the data preprocessing. In the present work, the limitations of the baseline correction method based on polynomial fitting were highlighted and a modified polynomial fitting method, i.e. piecewise linear fitting method, was proposed. Combined with the computer, this method could eliminate the baseline automatically. A series of Raman spectra of single polystyrene bead, red blood cell or yeast cell acquired by laser tweezers Raman spectroscopy were preprocessed by this method and its efficiency was verified. The results demonstrated that piecewise linear fitting can correct the baseline shifts effectively and provides more accurate information for further data analysis. It is a feasible method for correction of Raman spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 383 (2013)
Preparation of a Kind of SERS-Active Substrates for Spot Fast Analysis
JI Nan, LI Zhi-shi, ZHAO Bing, and ZOU Bo
A kind of SERS-active substrates was prepared using chemical self-assembly method, aiming at spot fast analysis using portable Raman spectrometer. PDDA was first absorbed on the inner wall of vials, and then Ag colloids were assembled on the inner wall. UV-Vis spectra and Raman spectra of two kinds of blank vials were A kind of SERS-active substrates was prepared using chemical self-assembly method, aiming at spot fast analysis using portable Raman spectrometer. PDDA was first absorbed on the inner wall of vials, and then Ag colloids were assembled on the inner wall. UV-Vis spectra and Raman spectra of two kinds of blank vials were investigated and the transparent vials were thought to be better for SERS-vials. UV-Vis spectra were used to monitor the assembly process of Ag colloids. SERS activity of our substrates was characterized using p-ATP as probing molecules..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 387 (2013)
Research on Raman Spectra Quantitative Analysis Model of Ethanol Aqueous Solution Based on Net Analyte Signal
LI Qing-bo, YU Chao, and ZHANG Qian-xuan
Raman spectroscopy technique could satisfy industrial field measurement requirements because of the advantages of rapidity and nondestructiveness. Thus, It has been widely used in a variety of quantitative and qualitative analysis fields. The volume ration of alcohol and water in alcoholic beverages, i.e. the ethanol cRaman spectroscopy technique could satisfy industrial field measurement requirements because of the advantages of rapidity and nondestructiveness. Thus, It has been widely used in a variety of quantitative and qualitative analysis fields. The volume ration of alcohol and water in alcoholic beverages, i.e. the ethanol content, is a key factor in the detection of the quality of wine products. The development of the detection system for quick, easy and real-time ethanol content measurement is of great significance for national production. In the present paper, net signal analysis method (NAS) was used in the ethanol content quantitative analysis of Raman spectra from the ethanol aqueous solution. The linear regression model was developed between the net signal of ethanol and its concentration. The results showed that the qualitative analysis method based on net signal analysis was superior to the traditional linear regression method such as the MLR method based on the feature peak intensity and the PLS model. It not only improved the prediction accuracy of the model but also enhanced the robustness of the model. Because the model established by the NAS-MLR method is simple and stable, it is possible to develop the portable measurement instruments in future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 390 (2013)
Fluorescence Fingerprint——a Novel Tool of Quality Control of Chemical Reagents
WU Jing, XIE Chao-bo, CAO Zhi-ping, and YIN Dan-dan
Product quality control is crucial for industrial production, but there is lack of simple and effective detect methods. In this study, the chromatographically pure N-hexane from different manufacturers and same manufacturers with different batches was detected with fluorescence fingerprint technology. The results showeProduct quality control is crucial for industrial production, but there is lack of simple and effective detect methods. In this study, the chromatographically pure N-hexane from different manufacturers and same manufacturers with different batches was detected with fluorescence fingerprint technology. The results showed that the fluorescence fingerprints of all samples were different from each other. The numbers of fluorescence peaks of the fingerprints of the famous international manufacturer was stable and the intensity was low. The chromatographically pure N-hexane made in China generally had more peaks, higher intensities and greater changes as compared to the imported product. This indicated that the domestic products had more impurities with high concentration and the product quality was unstable. The study showed that the fluorescence fingerprint can be used as a novel method for quality control of chemical reagents..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 395 (2013)
Identification of Ichthyotoxic Microalgae Species and Its Hemolytic Activity by Three-Dimensional Fluorescence Spectra
HUAN Qing-liu, HUANG Xiang, WU Ni, JIANG Tao, and JIANG Tian-jiu
To identify ichthyotoxic microalgae species and its hemolytic activity by three-dimensional fluorescence spectra, the relationship between hemolytic activity and the three-dimensional fluorescence of typical ichthyotoxic algae (Karenia mikimotoi, Chattonella marina, Chattonella ovata) cultured in different Fe2+ concentTo identify ichthyotoxic microalgae species and its hemolytic activity by three-dimensional fluorescence spectra, the relationship between hemolytic activity and the three-dimensional fluorescence of typical ichthyotoxic algae (Karenia mikimotoi, Chattonella marina, Chattonella ovata) cultured in different Fe2+ concentrations was investigated with methods of Coif2 wavelet and Fisher discriminant analysis. The results showed that the differences of three-dimensional fluorescence spectra between ichthyotoxic algae and non-ichthyotoxic algae were within the 1 to 10 data points (wavelength λem=650～680 nm) and 35 to 47 data points (wavelength λem=725～750 nm, λex=400～425 nm). Fisher discriminant analysis showed that the correct discrimination ratios of ichthyotoxic algae and non-ichthyotoxic species are 91.7% and 100%, respectively, and the ratio of algae with medium hemolytic activity (≥10 HU, <20 HU) was 70% and that of algae with low hemolytic activity (<10 HU) and high hemolytic activity (≥20 HU) are both of above 80%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 399 (2013)
Identifying the Origin of Chromophoric Dissolved Organic Matter in Xiamen Bay Using Fluorescence Spectroscopy and Chemometrics
LIN Hui, GUO Wei-dong, XU Jing, and HU Ming-hui
The fluorescent components of chromophoric dissolved matter ( CDOM) in water samples collected from Xiamen Bay in spring and autumn, 2009 were examined using excitation-emission matrix fluorescence spectroscopy combined with parallel factor analysis (EEMs-PARAFAC). PARAFAC decomposed the fluorescence matrices of CDOM iThe fluorescent components of chromophoric dissolved matter ( CDOM) in water samples collected from Xiamen Bay in spring and autumn, 2009 were examined using excitation-emission matrix fluorescence spectroscopy combined with parallel factor analysis (EEMs-PARAFAC). PARAFAC decomposed the fluorescence matrices of CDOM into three humic-like (C1: 250, 345/454 nm; C2: 230, 310/374 nm; C5: 265, 424/478 nm) and two protein-like (C3: 230/342 nm; C4: 230, 275/322 nm) components. Good linear correlation occurred among three humic-like components and between two protein-like components, respectively. This demonstrated that the same types of components (humic-like or protein-like) have similar origin and geochemical behaviors. High abundances of humic-like components were found at the upstream zone of the Jiulong Estuary, while the high abundance of protein-like components occurred at the northern part of semi-enclosed Western Xiamen Harbor. The significant negative correlations were found between the abundances of all fluorescence components and salinity in the estuary area. However, the high contents of chlorophyll a were in line with the high abundances of C3 and C4 in non-estuarine area, which implies that phytoplankton activity could be another important source of protein-like components besides the river runoff. A principal component analysis(PCA) of fluorescent components revealed that terrestrial runoff was the dominant sources of CDOM fluorescence components in Xiamen Bay, while the contribution of the in situ biological processes was relatively lower. This study demonstrates that the combination use of PARAFAC modeling and chemometrics (i.e. PCA) is very useful in identifying the origin of CDOM and quantifying the primary factors influencing their distributions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 404 (2013)
Study of PbSe Quantum Dots for Use in Luminescence Solar Concentrators
HU Wen-jia, ZHANG Yu, Jian Xu, and WANG Jing-kang
With the study of the characteristic of luminescence solar concentrator, a simple and practicable Monte Carlo simulation system was invented based on ray tracing method. PbSe quantum dots were successfully introduced into this system, and the optical parameter and quantum dots concentration were simulated and optimizedWith the study of the characteristic of luminescence solar concentrator, a simple and practicable Monte Carlo simulation system was invented based on ray tracing method. PbSe quantum dots were successfully introduced into this system, and the optical parameter and quantum dots concentration were simulated and optimized. The cost per unit of the solar cell base on luminescence solar concentrator was investigated, and it was found that the cost of traditional solar cells can be reduced by 49.2%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 409 (2013)
Fluorescence Properties of Municipal Wastewater with Industrial Wastewater as Major Components
DAI Chun-yan, WU Jing, XIANG Xi, XIE Chao-bo, YIN Dan-dan, CAO Zhi-ping, and L Qing
The present paper studied fluorescence fingerprint properties of the municipal wastewater with industrial wastewater as major components. There existed three typical fluorescence peaks in the excitation-emission matrix of the municipal wastewater, locating at about λex/λem of 275/310, 230/340 and 220/310 nm respectivelThe present paper studied fluorescence fingerprint properties of the municipal wastewater with industrial wastewater as major components. There existed three typical fluorescence peaks in the excitation-emission matrix of the municipal wastewater, locating at about λex/λem of 275/310, 230/340 and 220/310 nm respectively. The wastewater didn’t display typical protein-like fluorescence as the municipal wastewater with domestic sewage as major component. The fluorescence intensity of the wastewater was quite high with remarkable difference between workday and weekend. These might relate to the high content of industrial wastewater. The advantages of the fluorescence fingerprint such as easy and fast measurement and rich information about the components of wastewater make it a novel tool in water quality monitoring and early-warning..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 414 (2013)
Investigation of Nascent Polypropylene In-Reactor Alloy Particles
LUO Hua-lin, ZHANG Chun-bo, NIU Hui, ZHAO Ying, DONG Jin-yong, WU Jin-guang, and WANG Du-jin
Heterogeneous nascent particles were observed in a pilot product of polypropylene in-reactor alloy, which was polymerized by Ziegler-Natta/Metallocene hybrid catalyst using Spheripol technology. Most of the particles in the product are translucent, and opaque particles were observed as well. The differences in morpholoHeterogeneous nascent particles were observed in a pilot product of polypropylene in-reactor alloy, which was polymerized by Ziegler-Natta/Metallocene hybrid catalyst using Spheripol technology. Most of the particles in the product are translucent, and opaque particles were observed as well. The differences in morphology, composition, chain structure, thermal properties and mechanical properties between these two kinds of particles were investigated by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), polarized optical microscopy (POM), and differential scanning calorimetry (DSC) techniques. The results of FTIR, NMR and SEM indicate that different morphology of these two different particles is caused by different content of ethylene-propylene copolymers. The results of DSC and POM showed that the translucent particles has higher crystallization rate than opaque particles due to the presence of ethylene-propylene copolymers. The mechanical properties results showed that the impact resistance property of opaque particles is obviously lower than that of translucent particles, while its tensile strength and bending modulus are much higher than that of translucent particles. Based on the process of Spheripol technology, a preliminary explanation for the formation of different nascent PP in-reactor alloy particles is proposed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 418 (2013)
Physical Stability of Imidacloprid Suspension Concentrate Studied by the Multiple Light Scattering Technique
ZHANG Xiao-jun, FENG Jian-guo, LIU Shang-zhong, and WU Xue-min
The stability of pesticide SC suspension was studied by Turbiscan Lab Analyzer. The Turbiscan Lab can be used to analyze the concentrated colloids, dispersant samples, and the instable mechanism of the suspension system in the initial stage. The Turbiscan Lab can also determine the thickness changes of sedimentation wiThe stability of pesticide SC suspension was studied by Turbiscan Lab Analyzer. The Turbiscan Lab can be used to analyze the concentrated colloids, dispersant samples, and the instable mechanism of the suspension system in the initial stage. The Turbiscan Lab can also determine the thickness changes of sedimentation with the time, the settling rate of particles with time, and the particle size changes with time. In the present work, the different dispersant GY-D10, NNO, Morwet D-425, TERSPERSE 2425 were used to prepare the imidacloprid 350 g·L-1 suspension concentrate in the same preparation condition. By measuring the light intensity of backscattering light of the suspension of imidacloprid 350 g·L-1 SC with time, the dynamic sedimentation processes and the particle size changes which reflect the stability of SC suspension were studied. The results showed that when the contents of GY-D10 dispersant were 4 wt% in the SC, the stability of SC suspension system was relatively good..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 423 (2013)
Spectral Features Analysis of Pinus massoniana with Pest of Dendrolimus punctatus Walker and Levels Detection
XU Zhang-hua, LIU Jian, YU Kun-yong, GONG Cong-hong, XIE Wan-jun, TANG Meng-ya, LAI Ri-wen, and LI Zeng-lu
Taking 51 field measured hyperspectral data with different pest levels in Yanping, Fujian Province as objects, the spectral reflectance and first derivative features of 4 levels of healthy, mild, moderate and severe insect pest were analyzed. On the basis of 7 detecting parameters construction, the pest level detectingTaking 51 field measured hyperspectral data with different pest levels in Yanping, Fujian Province as objects, the spectral reflectance and first derivative features of 4 levels of healthy, mild, moderate and severe insect pest were analyzed. On the basis of 7 detecting parameters construction, the pest level detecting models were built. The results showed that (1) the spectral reflectance of Pinus massoniana with pests were significantly lower than that of healthy state, and the higher the pest level, the lower the reflectance; (2) with the increase in pest level, the spectral reflectance curves’ “green peak” and “red valley” of Pinus massoniana gradually disappeared, and the red edge was leveled; (3) the pest led to spectral “green peak” red shift, red edge position blue shift, but the changes in “red valley” and near-infrared position were complicated; (4) CARI, RES, REA and REDVI were highly relevant to pest levels, and the correlations between REP, RERVI, RENDVI and pest level were weak; (5) the multiple linear regression model with the variables of the 7 detection parameters could effectively detect the pest levels of Dendrolimus punctatus Walker, with both the estimation rate and accuracy above 0.85..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 428 (2013)
Determination of Nitrate and Nitrite in Water Samples Using Gallery Automatic Discrete Analyzer
HAO Hong, ZHOU Huai-dong, GAO Bo, LIU Qian-qian, LU Jin, GAO Ji-jun, and YUAN Hao
Thermo Scientific Gallery Automatic Discrete Analyzer is special for water analyzing, and can automatically run steps includeing sample and reagents dispensing, water blank, mixing and incubation, Colorimetric reading and data processing. This method refers to U.S. Environmental Protection Agency. The instrument has adThermo Scientific Gallery Automatic Discrete Analyzer is special for water analyzing, and can automatically run steps includeing sample and reagents dispensing, water blank, mixing and incubation, Colorimetric reading and data processing. This method refers to U.S. Environmental Protection Agency. The instrument has advantage in low sample and reagents consumption, sensitivity and repeatability; test process can be automatic, standardized and informationized, and is applicable to multitudinous sample testing in water qualities and environmental monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 434 (2013)
The Symmetric Zero-Area Conversion Adptive Peak-Seeking Method Research for LIBS/Raman Spectra
BI Yun-feng, LI Ying, and ZHENG Rong-er
Automatic peak seeking is an indispensable link for in situ and real-time spectral detection and analysis, and has important significance for application of spectral technology to such fields as long-term marine monitoring and oil mud logging. Based on some typical LIBS/Raman spectrum data obtained from lab, three kindAutomatic peak seeking is an indispensable link for in situ and real-time spectral detection and analysis, and has important significance for application of spectral technology to such fields as long-term marine monitoring and oil mud logging. Based on some typical LIBS/Raman spectrum data obtained from lab, three kinds of symmetric zero-area transformation functions respectively constructed from Gaussian, Lorentz and Voigt function were compared, and the results show that there exists an optimal symmetrical zero-area transformation function for peak seeking, but all the transformation functions obtain the same peak position and peak width under their optimal parameters. The proposed method is free from spectrum background and baseline trend influence, adaptive to the wide range of SNR, close to or even better than artificial recognition for weak peak, and could be used in future automatic in-situ analysis of LIBS and Raman..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 438 (2013)
Measurement of Atmospheric NO3 Radical with Long Path Differential Optical Absorption Spectroscopy Based on Red Light Emitting Diodes
LI Su-wen, LIU Wen-qing, WANG Jiang-tao, XIE Pin-hua, and WANG Xu-de
Nitrate radical (NO3) is the most important oxidant in the tropospheric nighttime chemistry. Due to its high reactivity and low atmospheric concentrations, modern red light emitting diodes (LEDs) was proposed as light source in long path differential optical absorption spectroscopy (LP-DOAS) to measure NO3 radical in tNitrate radical (NO3) is the most important oxidant in the tropospheric nighttime chemistry. Due to its high reactivity and low atmospheric concentrations, modern red light emitting diodes (LEDs) was proposed as light source in long path differential optical absorption spectroscopy (LP-DOAS) to measure NO3 radical in the atmosphere. The spectral properties of Luxeon LXHL-MD1D LEDs were analyzed in the present paper. The principle of LEDs-DOAS system to measure nitrate radical was studied in this paper. The experimental setup and retrieval method of NO3 radical were discussed in this paper. The retrieved example of NO3 was given and the time series of NO3 concentrations was performed for a week. The results showed that the detection limits of LEDs-DOAS system were 12 ppt for atmospheric NO3 radical when the optical path of LEDs-DOAS system was 2.8 km..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 444 (2013)
Algorithm of Locally Adaptive Region Growing Based on Multi-Template Matching Applied to Automated Detection of Hemorrhages
GAO Wei-wei, SHEN Jian-xin, WANG Yu-liang, LIANG Chun, and ZUO Jing
In order to automatically detect hemorrhages in fundus images, and develop an automated diabetic retinopathy screening system, a novel algorithm named locally adaptive region growing based on multi-template matching was established and studied. Firstly, spectral signature of major anatomical structures in fundus was stIn order to automatically detect hemorrhages in fundus images, and develop an automated diabetic retinopathy screening system, a novel algorithm named locally adaptive region growing based on multi-template matching was established and studied. Firstly, spectral signature of major anatomical structures in fundus was studied, so that the right channel among RGB channels could be selected for different segmentation objects. Secondly, the fundus image was preprocessed by means of HSV brightness correction and contrast limited adaptive histogram equalization(CLAHE). Then, seeds of region growing were founded out by removing optic disc and vessel from the resulting image of normalized cross-correlation(NCC)template matching on the previous preprocessed image with several templates. Finally, locally adaptive region growing segmentation was used to find out the exact contours of hemorrhages, and the automated detection of the lesions was accomplished. The approach was tested on 90 different resolution fundus images with variable color, brightness and quality. Results suggest that the approach could fast and effectively detect hemorrhages in fundus images, and it is stable and robust. As a result, the approach can meet the clinical demands..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 448 (2013)
Analysis of Typical Mangrove Spectral Reflectance Characteristics
YU Xiang, ZHANG Feng-shou, LIU Qing, LI De-yi, and ZHAO Dong-zhi
Acquisition of mangrove spectrum properties and detecting the sensitive bands provide technology basis for inverse modeling and estimation by remote sensing for various indexes of mangrove. The typical mangroves of Guangxi Shankou Mangrove Reserve were taken for study objects, the standard spectrum curves of Bruguiera Acquisition of mangrove spectrum properties and detecting the sensitive bands provide technology basis for inverse modeling and estimation by remote sensing for various indexes of mangrove. The typical mangroves of Guangxi Shankou Mangrove Reserve were taken for study objects, the standard spectrum curves of Bruguiera gymnorrhiza (Linn.) Savigny, Rhizophora stylosa, Kandelia candel, Avicennia marina, Aegiceras corniculatum, Spartina anglica and mudflat were gained by de-noising analysis of field-measured spectrum curves acquired by ASD FieldSpec 2. Analyzing the spectral characteristics and their differences, the authors found that the spectrum curves for various kinds of mangrove are coincident, the bands that appeared with reflection peaks and reflection valleys are basically identical, the within-class differentiated characteristics are comparatively small, the spectrum characteristics of mangroves are obviously different with Spartina anglica and mudflat. In order to gain the quantitative description for within-class differentiated characteristics of mangrove, space distance method, correlation coefficient method and spectral angle mapping method were used to calculate the within-class differentiated characteristics. The division accuracy of correlation coefficient method is higher than spectral angle mapping method which is higher than space distance method, and the result indicates that the spectrum differences of within-class mangrove and Spartina anglica are relatively small with correlation coefficients more than 0.995, and spectrum curve angle cosine values more than 0.95..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 454 (2013)
A Spectrum Extraction Method Based on Uncertainty in Noninvasive Blood Components Examinaton
LIN Ling, XIONG Bo, ZHAO Shuang-qi, LIU Gui-li, WANG Xiao-fei, and LI Gang
An improved spectrum extraction method is proposed based on the dynamic spectrum theory to improve the precision. First, the drift baseline is fitted to restrain the effect of relative motion between the finger and the probe. Then, the spectrum is extracted using the square-sum-root method as a replacement of the peak-An improved spectrum extraction method is proposed based on the dynamic spectrum theory to improve the precision. First, the drift baseline is fitted to restrain the effect of relative motion between the finger and the probe. Then, the spectrum is extracted using the square-sum-root method as a replacement of the peak-peak value method to reduce the impact of system random error. Taking the measurement of oxygen saturation for instance, uncertainty analysis is performed for the oxygen saturation coefficient Q. Compared with the peak-peak value method, the square-sum-root method can reduce the uncertainty of oxygen saturation coefficient Q to 38% of the original value. Ten data sets were sampled from ten volunteers, and the uncertainty of the coefficient Q obtained using the two methods was directly evaluated and compared. The average ratio of the Q uncertainty by the two methods turned to be 42%. Both the theoretical analysis and the experimental results show that the square-sum-root method proposed can be used to extract the effective spectra more accurately from the photoplethysmography, suggesting a meaningful progress in noninvasive blood components measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 459 (2013)
Data Mining for Cataclysmic Variables Candidates in SDSS-DR8
JIANG Bin, PAN Jing-chang, and WANG Wei
An automatic and efficient method for cataclysmic variables candidates is presented in this paper. The nonlinear locally linear embedding-LLE method is applied in the newly released SDSS-DR8 spectra. Spectra are dimension-reduced by LLE and classified by artificial neural network. The greatly reduced final candidates cAn automatic and efficient method for cataclysmic variables candidates is presented in this paper. The nonlinear locally linear embedding-LLE method is applied in the newly released SDSS-DR8 spectra. Spectra are dimension-reduced by LLE and classified by artificial neural network. The greatly reduced final candidates can be identified manually. 6 new CVs candidates were found in the experiment, and the compare between LLE with PCA shows the feasibility of nonlinear method in data mining in astronomical data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 464 (2013)
Preparation by Spin-Coating Technology and Characterization of UV-Enhanced Lumogen Film
JIANG Lin, ZHANG Da-wei, TAO Chun-xian, HUANG Yuan-shen, WANG Qi, NI Zheng-ji, and ZHUANG Song-lin
As an effective way to increase the UV response for CCD/CMOS, the advantage of the Lumogen film is the simple process and low cost. In the present paper the Lumogen film was deposited onto fused silica slides by the spin-coating way, which has less damage than PVD physical vacuum deposition) way. The main test and analAs an effective way to increase the UV response for CCD/CMOS, the advantage of the Lumogen film is the simple process and low cost. In the present paper the Lumogen film was deposited onto fused silica slides by the spin-coating way, which has less damage than PVD physical vacuum deposition) way. The main test and analysis of the thin-film include transmission spectrum, absorption spectrum, and excitation and emission spectrum. It was showed that these coatings were transmitted well in visible region (λ>400 nm), and emitted a yellowish green glow centered at ～525 nm together with a wide excitation spectrum range from 200 to 400 nm. The synthesis shows that Lumogen coatings match accurately with the detected spectrum of conventional silicon-based image sensors, which makes this kind of thin films an ultraviolet responsive coating for sensors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 468 (2013)
Application of the Vanillin Sulfuric Acid Colorimetry-Ultraviolet Spectrometry on Quality Evaluation of Panax notoginseng
DING Yong-li, WANG Yuan-zhong, ZHANG Ji, ZHANG Qing-zhi, ZHANG Jin-yu, and JIN Hang
In this study, Panax notoginseng samples were extracted by chloroform, ethanol and water, or by those extracted solution with 5% vanillin sulfuric acid to establish two kinds of UV fingerprint of P. notoginseng which were compared by applying the common and variation peak ratio dual index sequence analysis method and SIn this study, Panax notoginseng samples were extracted by chloroform, ethanol and water, or by those extracted solution with 5% vanillin sulfuric acid to establish two kinds of UV fingerprint of P. notoginseng which were compared by applying the common and variation peak ratio dual index sequence analysis method and SIMCA software qualitative analysis. The results indicated that the optimization extraction time of P. notoginseng samples was 20 min with chloroform, ethanol and water extraction, but the fingerprint differed significantly after add vanillin sulfuric acid. The common peak ratios of UV fingerprint of P. notoginseng were scattered. The minimum was 25%(Y5—Y8), while the maximum was 84.38%(Y11—Y13, Y20—Y21). The maximum variation peak ratio was 177.78%(Y8—Y5), meanwhile, the variation peak ratios of several samples were more than 100%. However, the common peak ratios of UV fingerprint of P. notoginseng with vanillin sulfuric acid were concentrated (distributed in the range of 50%～70%): the minimum was 42. 86%(Y1—Y19), whereas the maximum was 79.55% (Y22—Y23); the range of the variation peak ratios was also smaller with the ranges of 20%～50% in general. The result of the dual index sequence analysis was agreement with the fingerprint implied. The similarity of the UV fingerprint of the extracts of P. notoginseng after adding vanillin sulfuric acid was greater than before. Both the ages and origin was related with the difference of UV fingerprint. The similarity of the two samples with same age was more significant than those with different ages. The similarity and difference between samples was no correlation with the distance of geographic space, the near origin samples maybe have a significant similarity or difference. This method appears as good alternative for evaluate quality of the P. notoginseng and can distinguish at least two samples quantitatively, duo to it reaches the limitation of the multiple methods which only could be used to indistinctly distinguish herbs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 471 (2013)
Distribution Characteristics of Soil Cadmium in Different Textured Paddy Soil Profiles and Its Relevance with Cadmium Uptake by Crops
QIN Yu-sheng, ZHAN Shao-jun, YU Hua, TU Shi-hua, and WANG Zheng-yin
Adopting atomic absorption spectrometry (novAA400), the present study investigated the distribution characteristics of soil cadmium (Cd) in different textured paddy soil profiles under rice-wheat rotation and its correlation with Cd uptake by rice and wheat in Chengdu Plain through repeatedly taking soil and plant sampAdopting atomic absorption spectrometry (novAA400), the present study investigated the distribution characteristics of soil cadmium (Cd) in different textured paddy soil profiles under rice-wheat rotation and its correlation with Cd uptake by rice and wheat in Chengdu Plain through repeatedly taking soil and plant samples at the fixed sites in the field. The results revealed that Cd in the paddy soil profiles was mainly concentrated at the plough layer (0～15 cm) that obviously featured ‘Cd accumulates towards the rooting layer’. Soil total Cd and available Cd (1 mol·L-1 MgCl2 extraction) in the profile declined with soil depths and its average values at 30～45 cm only accounted for 47.60% and 39.49% of those at 0～15 cm. The potential downward movement of Cd in the different textured soil profiles was observed as sandy loam>heavy loam>loam. There was no significant correlation between soil pH and available Cd(r=－0.46) at 0～15 cm soil depth, while significantly negative correlations between soil pH and available Cd were observed at 15～30 cm (r=－0.78) and 30～45 cm (r=－0.86). The results further demonstrated that the Cd contents in either grain or straw of rice and wheat were not well correlated with soil total Cd at any soil depth (r=－0.092～0.383 for rice and r=0.174～0.424 for wheat), but significantly correlated with soil available Cd at 0～15 cm and at 15～30 cm (r=0.766*～0.953**) despite insignificant correlation at 30～45 cm (r=0.526～0.584). It is strongly suggested that the soil available Cd can be used as a better criterion than the total soil Cd to rate Cd contaminated soils in relation to safety of agricultural products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 476 (2013)
Synthesis, Crystal Structure and Spectral Properties Study of a 3D Netlike Coordination Polymer ［Zn(HBIDC)·H2O］n
DONG Yu-wei, FAN Rui-qing, WANG Ping, WANG Li-yuan, and YANG Yu-lin
The 3D netlike coordination polymer of ZnⅡ with benzimidazole-5,6-dicarboxylic acid (H3BIDC), ［Zn(HBIDC)·H2O］n was synthesized by the hydrothermal method through self-assembling. The crystal structure of complex 1 was characterized by single-crystal X-ray diffraction, elemental analysis and IR spectra, and we alsoThe 3D netlike coordination polymer of ZnⅡ with benzimidazole-5,6-dicarboxylic acid (H3BIDC), ［Zn(HBIDC)·H2O］n was synthesized by the hydrothermal method through self-assembling. The crystal structure of complex 1 was characterized by single-crystal X-ray diffraction, elemental analysis and IR spectra, and we also studied the fluorescence properties of complex 1 in DMSO and in the solid state with UV-Vis absorption spectra, fluorescence spectra and fluorescence lifetime. Complex 1 has blue luminescence in solutions of DMSO with emission band at 481 nm; and has blue luminescence in the solid state at room temperature with a strong emission band at 493 nm, and these all can be attributed to the π*→π transition based on the benzimidazole-5,6-dicarboxy acid. The experimental results indicate that complex 1 displays higher fluorescence quantum efficiency and can be used as a potential blue luminescence material..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 481 (2013)
Spectral Characteristics of Ba3SiO4Cl2∶Eu2+ Phosphor for White LED
WANG Zhi-jun, LI Pan-lai, YANG Zhi-ping, and GUO Qing-lin
Ba3SiO4Cl2∶Eu2+ was synthesized by a high temperature solid state method. BaCO3 (A.R.), BaCl2 (A.R.), SiO2 (99.99%) and Eu2O3 (99.99%) were used as the raw materials. The final phase was checked with a conventional X-ray diffraction (XRD) (D/max-rA, CuKα, 40 kV, 100 mA, λ=0.154 06 nm). The spectral characteristics of tBa3SiO4Cl2∶Eu2+ was synthesized by a high temperature solid state method. BaCO3 (A.R.), BaCl2 (A.R.), SiO2 (99.99%) and Eu2O3 (99.99%) were used as the raw materials. The final phase was checked with a conventional X-ray diffraction (XRD) (D/max-rA, CuKα, 40 kV, 100 mA, λ=0.154 06 nm). The spectral characteristics of the phosphors were performed by using a Hitachi F-4600 fluorescence spectrophotometer equipped with a 450 W Xe lamp. Ba3SiO4Cl2∶Eu2+ showed broad emission bands at 445 and 510 nm under the 365 nm radiation excitation. For the two emission peaks, the excitation spectra have two different spectral distributions, and the excitation peaks locate at 350 and 400 nm, respectively. The results indicate that different Eu2+ emission centres exist in Ba3SiO4Cl2. The emission intensity of the 445 and 510 nm peaks is influenced by Eu2+ doped content. With increasing its content, the emission intensity of 445 nm gradually increases, and that of 510 nm decreases. With washing the phosphor, the 445 nm emission peak disappears, and the emission spectrum has only the 510 nm emission band, and its intensity is lower than that of the original phosphor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 486 (2013)
The Influence of Junction Temperature on the White LED Spectral Characteristics of the Mixture of the DCJTB and YAG∶Ce3+
LIANG Tian-jing, ZHANG Fang-hui, QU Shao-jun, HAN Liang, and QIU Xi-zhen
The present paper mainly studies the influence of the junction temperature on the white LED spectral characteristics of the mixture of the DCJTB and YAG∶Ce3+ phosphor. With layered coating of YAG phosphor and organic materials DCJTB on the LED chip with the method of hierarchical point powder, the color rendering indexThe present paper mainly studies the influence of the junction temperature on the white LED spectral characteristics of the mixture of the DCJTB and YAG∶Ce3+ phosphor. With layered coating of YAG phosphor and organic materials DCJTB on the LED chip with the method of hierarchical point powder, the color rendering index of the device will reach up to 90. The junction temperature can be measured conveniently and accurately with the integrated LED cooling pad which was developed by the laboratory. Experiments show that: the rise of the junction temperature can make the radiation amplitude of the blue chip decline continuously. The yellow radiation amplitude of YAG phosphor which is excited by radiation first increases and then decreases, the red spectrum is blue-shifted, the color rendering index of the device decreased linearly, while the color temperature first increases and then decreases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 490 (2013)
Studies on Hyperspectral Characteristics of Microcystis Aeruginosa under the Cultivation Conditions with Different Phosphorus Concentrations
QIN Zhao-yang, LIU Xue-hua, and ZHAO Jin-bo
Microcystis aeruginosa is one of the most common species in the algae-bloom events of domestic lakes. Illumination incubator was used to cultivate M. aeruginosa under conditions of different phosphorus concentrations in the laboratory. Spectroscopic data of culture solutions were collected by GER1500 spectrometer underMicrocystis aeruginosa is one of the most common species in the algae-bloom events of domestic lakes. Illumination incubator was used to cultivate M. aeruginosa under conditions of different phosphorus concentrations in the laboratory. Spectroscopic data of culture solutions were collected by GER1500 spectrometer under the sunlight. The study focused on the growth rhythm of M. aeruginosa and the characteristics of spectral variation in the culture solutions. The results showed that low phosphorus concentration (≤10 μg·L-1) is a restricting factor for the growth and reproduction of M. aeruginosa. Moreover, the reflections of spectrum from culture solutions of M. aeruginosa showed significant changes along with cultivation period, such as at the wavelengths of 550, 610, 660, 700～710 and 760 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 494 (2013)
Hyperspectral Remote Sensing Retrieval of Inherent Optical Properties in the Bohai Sea
QING Song, ZHANG Jie, and BAO Yu-hai
Inherent optical properties are important marine optical parameters which are the basic input parameters of the radiative transfer model. Based on hyperspectral remote sensing reflectance and total absorption coefficient data measured in 2005 in the Bohai Sea, the nonlinear minimization model was firstly used to retrieInherent optical properties are important marine optical parameters which are the basic input parameters of the radiative transfer model. Based on hyperspectral remote sensing reflectance and total absorption coefficient data measured in 2005 in the Bohai Sea, the nonlinear minimization model was firstly used to retrieve the inherent optical properties. The model was validated by in situ data. The averaged percent errors were 33.8%, 20.4%, 27.7%, 37.5%, 9.5% and 10.8% for the total absorption coefficients at 412, 440, 510, 555, 650 and 676 nm bands respectively. The main error sources of model were the uncertainty of the model parameters and measurement errors. According to the discussion, the spectral slope S has a slight influence on the retrieval of total absorption coefficients. However, the impact of the spectral power Y on the retrieval cannot be negligible. The model is suitable for hyperspectral data and can fulfill the gaps of inherent optical properties retrieval research in the Bohai Sea, so it can be used for hyperspectral remote sensing data to retrieve inherent optical properties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 498 (2013)
Influence of Soil Iron Oxide on VNIR Diffuse Reflectance Spectroscopy
PENG Jie, XIANG Hong-ying, ZHOU Qing, ZHANG Yang-zhu, WANG Jia-qiang, and PANG Xin-an
he influences of iron oxide on soil reflectance, soil line parameter, organic matter spectral characterization and the shape of soil reflectance spectra were studied in the present paper with thirteen samples in several soil types, which covered a range of iron oxide content obtained from various combination of originahe influences of iron oxide on soil reflectance, soil line parameter, organic matter spectral characterization and the shape of soil reflectance spectra were studied in the present paper with thirteen samples in several soil types, which covered a range of iron oxide content obtained from various combination of original and iron-removing samples. The results highlight that (1) a decrease on 350～570 nm and an increase on 570～2 500 nm were showed in the reflectance spectra with increasing iron oxide content. However, there was no significant correlation between iron oxide and spectral reflectance quantitatively; (2) iron oxide content had a negative linear correlation with soil line slope and a positive linear correlation with intercept, both were significant, which illustrated the feasibility of iron oxide prediction using soil line parameter; (3) the spectral characteristics of soil organic matter could be covered by iron oxide on 622～851 nm; (4) iron oxide in soil had influence on the shape of reflectance spectra after continuum removal and calculating statistical F and spectral angle..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 502 (2013)
Discussion on Hyperspectral Index for the Estimation of Cotton Canopy Water Content
WANG Qiang, YI Qiu-xiang, BAO An-ming, and ZHAO Jin
Proper vegetation indices have decisive influences on the precision of hyperspectral estimation models for surface parameters. In the present paper, in order to find the proper hyperspectral indices for cotton canopy water content estimation, two water parameters for cotton canopy water content (EWTcanopy, equivalent wProper vegetation indices have decisive influences on the precision of hyperspectral estimation models for surface parameters. In the present paper, in order to find the proper hyperspectral indices for cotton canopy water content estimation, two water parameters for cotton canopy water content (EWTcanopy, equivalent water thickness; VWC, vegetation water content) and corresponding hyperspectra data were analyzed. A rigorous search procedure was used to determine the best index predictors of cotton canopy water. In the procedure, all possible ratio indices and normalized difference indices were derived from the canopy hyperspectra, involving all the two-band combinations between 350nm and 2500nm. Then the correlation between two water parameters and all combination indices were analyzed, and the best indices which produced maximum correlation coefficients were determined. Finally, the indices were compared with the published water indices for their performances in estimation of cotton canopy water content. The results showed that for the estimation of EWTcanopy, the new developed ratio index R1 475/R1 424 and normalized difference index (R1 475-R1 424)/(R1 475+R1 424) was the most proper one, and the correlation coefficient of the estimated and measured EWTcanopy reached 0.849. For the estimation of VWC, the performance of published index was better than new developed index, the best suitable water indices for VWC estimation were (R835-R1 650)/(R835+R1 650), and the correlation coefficient of the estimated and measured VWC was 0.849..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 507 (2013)
Influence of Sensor Spectral Parameters on the Simulation of Hypespectral Data Based on the Spectral Reconstruction Approach
LIU Sui-hua, YAN Lei, YANG Bin, and FU Peng
Data simulation has been widely used in various applications of remote sensing, especially in design of new type sensors, test of new developed algorithms and other associated applications. However, change of parameters of sensor and its system can affect the accuracy of data simulations. Based on spectral reconstructiData simulation has been widely used in various applications of remote sensing, especially in design of new type sensors, test of new developed algorithms and other associated applications. However, change of parameters of sensor and its system can affect the accuracy of data simulations. Based on spectral reconstruction, the present study employs convolution of spectral response function (SRF) of four bands-blue, green, red, and infrared red within the wide field of view multispectral imager to analyze the impact central wavelength and bandwidth have on the accuracy of spectral reconstruction. The results show that root mean square error (RMSE) caused by central wavelength displacement is less than 0.025, while RMSE caused by bandwidth shift is less than 0.012, indicating the good accuracy of data simulations. Apparently, central wavelength and bandwidth have impact on accuracy of spectral reconstruction to some extent. Therefore, hyperspectral reconstruction depending on central wavelength and bandwidth is conducive for users to further understand hyperspectral imaging system, to find the main factor(s) influencing system performance, to better simulate hyperspectral data and to broaden the application range of remotely sensed data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 513 (2013)
Maize Seed Identification Using Hyperspectral Imaging and SVDD Algorithm
ZHU Qi-bing, FENG Zhao-li, HUANG Min, and ZHU Xiao
The sufficiency of feature extraction and the rationality of classifier design are two key issues affecting the accuracy of maize seed recognition. In the present study, the hyperspectral images of maize seeds were acquired using hyperspectral image system, and the image entropy of maize seeds for each wavelength was eThe sufficiency of feature extraction and the rationality of classifier design are two key issues affecting the accuracy of maize seed recognition. In the present study, the hyperspectral images of maize seeds were acquired using hyperspectral image system, and the image entropy of maize seeds for each wavelength was extracted as classification features. Then, support vector data description (SVDD) algorithm was used to develop the classifier model for each variety of maize seeds. The SVDD models yielded 94.14% average test accuracy for known variety samples and 92.28% average test accuracy for new variety samples, respectively. The simulation results showed that the proposed method implemented accurate identification of maize seeds and solved the problem of misclassification by the traditional classification algorithm for new variety maize seeds..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 517 (2013)
Research on Lettuce Leaves’ Moisture Prediction Based on Hyperspectral Images
SUN Jun, WU Xiao-hong, ZHANG Xiao-dong, and GAO Hong-yan
In order to conduct rational management of watering lettuce, the model of detecting lettuce leaves’ moisture was built. First of all, the hyperspectral images of lettuce leaves were acquired and simultaneously the moisture proportions of leaves were measured. Meanwhile, hyperspectral images were analyzed and the characIn order to conduct rational management of watering lettuce, the model of detecting lettuce leaves’ moisture was built. First of all, the hyperspectral images of lettuce leaves were acquired and simultaneously the moisture proportions of leaves were measured. Meanwhile, hyperspectral images were analyzed and the characteristic bands of lettuce leaves’ moisture were found. Then the images in characteristic bands were processed and the image features of lettuce leaves’ moisture were computed. The image features highly relevant to moisture were obtained through correlation analysis. Furthermore, due to the possible correlation among image features, the principal components of the images were extracted by principal components analysis and were used as BP neural network’s inputs to establish PCA-ANN model. At the same time, other models were constructed by using BP neural network and traditional MLR (multiple liner regression) method respectively. Prediction examinations of the three models were made based on the same sample data. The experimental results show that the average prediction error of PCA-ANN prediction model of tillering stage reaches 9.323% which is improved compared with BP-ANN and MLR prediction models..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 522 (2013)
The Deposition of Elements in the Process of Laser Ablation of Silicon
WANG Shao-peng, FENG Guo-ying, DUAN Tao, and HAN Jing-hua
Laser processing in the semiconductor industry (especially silicon material) has broad application prospects. The interaction between the laser and silicon is complex, and the present paper mainly studied the silicon morphology in UV laser ablation and the influence law of ambient gas. Studies have shown that the laserLaser processing in the semiconductor industry (especially silicon material) has broad application prospects. The interaction between the laser and silicon is complex, and the present paper mainly studied the silicon morphology in UV laser ablation and the influence law of ambient gas. Studies have shown that the laser plasma ionization effect of silicon in the UV laser ablation has a decisive impact: the removal of the material becomes possible because of generating gasification and ionization, laser plasma shock wave can make phase transition material discharge effectively, and laser plasma spectroscopy ionization effect can make the oxygen elements in the air ionize and deposit effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 527 (2013)
The LIBS Experiment Condition Optimization of Alloy Steel
SHAO Yan, GAO Xun, DU Chuang, ZHAO Zhen-ming, CHEN Wei-yu, HAO Zuo-qiang, SUN Chang-kai, and LIN Jing-quan
Laser induced plasma spectroscopy of alloy steel was produced by Nd∶YAG pulsed laser at 1 064 nm, and the spectral signal was detected by high resolution and width controlled ICCD. Several Fe atomic spectral lines such as 404.581, 414.387, 427.176 and 438.355 nm were chosen for analysis, and the effects of different exLaser induced plasma spectroscopy of alloy steel was produced by Nd∶YAG pulsed laser at 1 064 nm, and the spectral signal was detected by high resolution and width controlled ICCD. Several Fe atomic spectral lines such as 404.581, 414.387, 427.176 and 438.355 nm were chosen for analysis, and the effects of different experimental parameters on LIBS spectral signal intensity were investigated. It is shown that the experimental parameters such as pulse energy, laser focus location and laser delay time have great influence on the LIBS signal. LIBS signals with high spectral intensity and signal-background ratio (SBR) as well as the optimum experiment conditions were obtained by optimizing these experiment parameters so as to make composition analysis of the alloy steel..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 531 (2013)
Research on the Atomic Emission Spectroscopy of Atmospheric Pressure Plasma Process
JIN Jiang, LI Na, XU Lu, WANG Bo, and JIN Hui-liang
In the reaction of the atmospheric pressure plasma process, the heat stable process of the atmospheric pressure plasma jet has a direct impact on the removal rate, CF4 is the provider of active F* atom, O2 is important auxiliary gas, and they play an important role in the process. In order to research the rule of the cIn the reaction of the atmospheric pressure plasma process, the heat stable process of the atmospheric pressure plasma jet has a direct impact on the removal rate, CF4 is the provider of active F* atom, O2 is important auxiliary gas, and they play an important role in the process. In order to research the rule of the concentration of the 3 parameters upon the atmospheric pressure plasma processing, the atmospheric pressure plasma jet was used for processing and the spectrometer was used to monitor the changes in the process. The experiment indicates that: when the heat is stable, the concentration of the active F* atom essentially remains unchanged; with increasing the concentration of gas CF4, the spectrum of the active F* atom has self-absorption phenomena, so using the atomic emission spectroscopy method to monitor the changes in the concentration of active F* atom generated by CF4 is not completely exact; because O2 can easily react with the dissociation product of CF4, which inhibits the compound of the active F* atom, so in a certain range with increasing the concentration of gas O2, the concentration of the active F* atom becomes strong..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 535 (2013)
Application of Atomic Absorption Spectrometry in the Engine Knock Detection
CHEN Li-dan
Because existing human experience diagnosis method and apparatus for auxiliary diagnosis method are difficult to diagnose quickly engine knock. Atomic absorption spectrometry was used to detect the automobile engine knock in an innovative way. After having determined Fe, Al, Cu, Cr and Pb content in the 35 groups of AuBecause existing human experience diagnosis method and apparatus for auxiliary diagnosis method are difficult to diagnose quickly engine knock. Atomic absorption spectrometry was used to detect the automobile engine knock in an innovative way. After having determined Fe, Al, Cu, Cr and Pb content in the 35 groups of Audi A6 engine oil whose travel course is 2 000~70 000 kilometers and whose sampling interval is 2 000 kilometers by atomic absorption spectrometry, the database of primary metal content in the same automobile engine at different mileage was established. The research shows that the main metal content fluctuates within a certain range. In practical engineering applications, after the determination of engine oil main metal content and comparison with its database value, it can not only help to diagnose the type and location of engine knock without the disintegration and reduce vehicle maintenance costs and improve the accuracy of engine knock fault diagnosis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 540 (2013)
Determination of Elements in Branches and Leaves and the Fruits of Sorbus Tianschanica Ruper. from Different Habitats in Xinjiang by Microwave Digestion-ICP-AES
HE Jia-wei, CHANG Jun-min, YAO Jun, ZHANG Qian, XUE Hai-yan, and LIU Yu-hua
The contents of ten elements Ca, K, Mg, Na, Fe, Mn, Zn, Cu, Pb and As in branches and leaves and the fruits of Sorbus tianschanica Ruper. from different habitats in Xinjiang were determined by ICP-AES using microwave digestion. The study indicated that the contents of elements in branches and leaves and the fruits of SThe contents of ten elements Ca, K, Mg, Na, Fe, Mn, Zn, Cu, Pb and As in branches and leaves and the fruits of Sorbus tianschanica Ruper. from different habitats in Xinjiang were determined by ICP-AES using microwave digestion. The study indicated that the contents of elements in branches and leaves and the fruits of Sorbus tianschanica Ruper. from different habitats in Xinjiang are different, and the contents of elements in branches are richer than that in the fruits of Sorbus tianschanica Ruper. The contents of Ca, K, Mg, Na, Fe, Mn, Zn, and Cu are all high, and the harmful elements such as Pb and As are low. The results provide scientific basis for the development and utilization of the medicinal resource of Sorbus tianschanica Ruper. in Xinjiang..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 544 (2013)
Comparison of Green Coffee Beans Volatiles Chemical Composition of Hainan Main Area
HU Rong-suo, CHU Zhong, GU Feng-lin, LU Min-quan, LU Shao-fang, WU Gui-ping, and TAN Le-he
Chemical component of Hainan green coffee beans was analyzed with solid phase microextraction-gas chromatography-mass spectrometry, and the discrepancy between two green coffee beans was differentiated through the spectrum database retrieval and retention index of compound characterization. The experimental results shoChemical component of Hainan green coffee beans was analyzed with solid phase microextraction-gas chromatography-mass spectrometry, and the discrepancy between two green coffee beans was differentiated through the spectrum database retrieval and retention index of compound characterization. The experimental results show that: the chemical composition of Wanning coffee beans and Chengmai coffee beans is basically the same. The quantity of analyzed compound in Wanning area coffee is 91, and in Chengmai area coffee is 106, the quantity of the same compound is 66, and the percent of the same component is 75.52%. The same compounds accounted for 89.86% of the total content of Wanning area coffee, and accounted for 85.70% of the total content of Chengmai area coffee..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 548 (2013)
Measurement and Analysis of Lead in Soil Using X-Ray Fluorescence Spectroscopy
ZHANG Rong, ZHANG Yu-jun, ZHANG Wei, CHEN Dong, YU Xiao-ya, and GAO Yan-wei
The present paper analyzed the characteristics of X-ray fluorescence spectroscopy (XRF) of metal element lead in soil using the NITON XLt793 portable X-ray fluorescence spectra of heavy metal analyzer under laboratory conditions. The characteristic spectral lines of Lα (energy: 10.55 keV) and Lβ(energy: 12.61 keV) withThe present paper analyzed the characteristics of X-ray fluorescence spectroscopy (XRF) of metal element lead in soil using the NITON XLt793 portable X-ray fluorescence spectra of heavy metal analyzer under laboratory conditions. The characteristic spectral lines of Lα (energy: 10.55 keV) and Lβ(energy: 12.61 keV) with different matrix elements were selected respectively for lead in the experiment. By measuring the intensities of the characteristic spectral line with different Pb concentration, the results demonstrate that the relation between concentration ［mass fraction 10×10-6～1 800×10-6］ of Pb element and the intensity of the characteristic spectrum is well linear. The calibration curve of Pb was plotted based on the different concentration measurement results, and the limit of detection of 7.89×10-6 was obtained for Pb in soil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 554 (2013)
Comparison of Different Template Matching Methods of Automatic Stellar Spectrum Parameter Measurement
LIU Jie, PAN Jing-chang, LIU Meng, WEI Peng, and LUO A-li
Template matching is one of the most commonly used methods of automatic stellar spectrum parameter measurement. The present paper made comparisons among the three commonly used template matching methods K-Nearest Neighbor (KNN), the Chi-square minimization and cross correlation method. The Continuum normalization and fTemplate matching is one of the most commonly used methods of automatic stellar spectrum parameter measurement. The present paper made comparisons among the three commonly used template matching methods K-Nearest Neighbor (KNN), the Chi-square minimization and cross correlation method. The Continuum normalization and flux normalization were made first. Then the three mentioned methods were compared in measurement results of stellar spectrum parameters. Experiments on SDSS DR8 large sample spectra showed that the cross correlation method had comparable advantages..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 558 (2013)
Study on an Optical System of Small Ultraviolet Imaging Spectrometer with High Resolution in Broadband
CONG Hai-fang, WANG Chun-hui, and WANG Yu
An ultraviolet imaging spectrometer was studied based on the principle of the small scale ultraviolet spectral instrument. The scheme composed of an off-axis parabolic mirror telescope and a single toroidal grating spectral imaging system was designed. The optimization of the optical system is the optimum processing foAn ultraviolet imaging spectrometer was studied based on the principle of the small scale ultraviolet spectral instrument. The scheme composed of an off-axis parabolic mirror telescope and a single toroidal grating spectral imaging system was designed. The optimization of the optical system is the optimum processing for the parameters of the toroidal grating. The optical path function and the aberration equations of the grating were analyzed. The perfect anastigmatism conditions and imaging conditions of the single toroidal grating system were obtained. These two conditions that cannot be satisfied by the algebra calculation method limit the field of view and waveband of the spectrometer. The genetic algorithm was introduced to solve the problem. A solar-blind ultraviolet imaging spectrometer for 200~280 nm was designed to verify the design method. The optimum initial configuration was calculated and simulated. A system with F/# 5.7, focal length 102 mm and high spatial resolution was designed. The modulation transfer functions (MTF) of all fields of view are more than 0.65 in the waveband in the required Nyquist frequency (20 lp·mm-1). The design results indicate that the optical system theory can be applied to the small scale ultraviolet imaging spectrometer with high resolution and spectral broadband..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 562 (2013)
The Echelle Grating Monochromator’s Design of Pure Rotational Raman Lidar
GE Xian-ying, CHEN Si-ying, ZHANG Yin-chao, CHEN He, GUO Pan, BU Zhi-chao, and CHEN Sheng-zhe
The pure rotational Raman Lidar temperature measurement system usually retrieve atmospheric temperature according to the echo signal of high and low-level quantum numbers of N2 molecules. An effective method to detect the rotational Raman spectrum is taking a grating monochromator. In the present paper the detection prThe pure rotational Raman Lidar temperature measurement system usually retrieve atmospheric temperature according to the echo signal of high and low-level quantum numbers of N2 molecules. An effective method to detect the rotational Raman spectrum is taking a grating monochromator. In the present paper the detection principle and the structure of the echelle grating monochromator are described, the high order and lower order quantum number of the probe spectrum is resolved. The focal length of the collimating-focusing optical system is calculated by analyzing echelle grating’s spectroscopic principle and dispersion ability. Subsequently spectral effect is simulated with Zemax software. The simulation result indicates that under the condition of the probe laser wavelength of 532 nm and using echelle grating monochromator, Raman spectrums of 529.05, 530.40, 533.77, 535.13 nm can be separated well, at the same time, the SNR of the system is enhanced by summing the spectral signals of symmetric quantum number. The echelle grating monochromator is small in size, and can easily meet the requirements of the miniaturization of Raman Lidar temperature measurement system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 567 (2013)
Spectral Calibratioo of Hyperspectral Imager Based on Spectral Absorption Target
GOU Zhi-yang, YAN Lei, CHEN Wei, ZHAO Hong-ying, YIN Zhong-yi, and DUAN Yi-ni
Retrieval of center wavelength and bandwidth is a key step for quantitative analysis of hyperspectral data. The present paper proposes a spectral calibration method of hyperspectral imager, whose spectrum covers visible and near-infrared band, using spectral absorption target. Ground calibration experiment was designedRetrieval of center wavelength and bandwidth is a key step for quantitative analysis of hyperspectral data. The present paper proposes a spectral calibration method of hyperspectral imager, whose spectrum covers visible and near-infrared band, using spectral absorption target. Ground calibration experiment was designed for a hyperspectral imager with a bandwidth of 6 nm. Hyperspectral imager and ASD spectrometer measured the same spectral absorption target synchronously. Reflectance spectrum was derived from the different data set. Center wavelength and bandwidth were retrieved by matching the reflectance data from hyperspectral imager and ASD spectrometer. The experiment result shows that this method can be applied in spectral calibration of hyperspectral imagers to improve the quantitative studies on hyperspectral imagery..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 571 (2013)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 2, 1 (2013)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20