Journals >Spectroscopy and Spectral Analysis
Contents
2012
Volume: 32 Issue 6
61 Article(s)
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Research Article
Application Progress of Laser-Induced Breakdown Spectroscopy for Surface Analysis in Materials Science Field
ZHANG Yong, JIA Yun-hai, CHEN Ji-wen, LIU Ying, SHEN Xue-jing, ZHAO Lei, WANG Shu-ming, YU Hong, HAN Peng-cheng, QU Hua-yang, and LIU Shao-zun
As a truly surface analytical tool, laser-induced breakdown spectroscopy (LIBS) was developed in recent ten years, and in this paper, fundamental theory, instrumentation and it’s applications in material science are reviewed in detail. Application progress of elemental distribution and depth profile analysis are mainlyAs a truly surface analytical tool, laser-induced breakdown spectroscopy (LIBS) was developed in recent ten years, and in this paper, fundamental theory, instrumentation and it’s applications in material science are reviewed in detail. Application progress of elemental distribution and depth profile analysis are mainly discussed in the field of metallurgy, semiconductor and electronical materials at home and abroad. It is pointed out that the pulse energy, ambient gas and it’s pressure, and energy distribution of laser beam strongly influence spatial and depth resolution, and meanwhile a approach to improving resolution considering analytical sensitivity is provided. Compared with traditional surface analytical methods, the advantage of LIBS is very large scanning area, high analytical speed, and that conducting materials or non-conducting materials both can be analyzed. It becomes a powerful complement of traditional surface analytical tool..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1441 (2012)
Spectral Characteristic of Short-Arc Xenon Lamp and Application in Solar Simulators
LI Qian, WANG Cheng, ZHA Jun, and XIA Wei-dong
Due to the inhomogeneous spatial spectral distribution of short-arc xenon lamp, its application is difficult. In the present paper，axially spectral distribution of xenon lamp was measured and temperature distribution was calculated, the temperature distribution was analysed as exponential relationship with arc current Due to the inhomogeneous spatial spectral distribution of short-arc xenon lamp, its application is difficult. In the present paper，axially spectral distribution of xenon lamp was measured and temperature distribution was calculated, the temperature distribution was analysed as exponential relationship with arc current density. Therefore，xenon lamp spectral distribution can be made closer to the standard solar simulator spectral distribution by controlling current density..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1447 (2012)
A Solar Blind Light Source with Long Dynamic Range
ZHOU Yue, YAN Feng, ZHANG Ming-chao, and GAO Song-tao
In order to realize the irradiance calibration of SBUV-ICCD (solar blind ultraviolent Intensified change-coupled device) with dynamic range reaching 120 dB, a light source with long dynamic range was designed and realized. Firstly, the irradiance dynamic range was estimated. Then using deuterium lamp, integrating spherIn order to realize the irradiance calibration of SBUV-ICCD (solar blind ultraviolent Intensified change-coupled device) with dynamic range reaching 120 dB, a light source with long dynamic range was designed and realized. Firstly, the irradiance dynamic range was estimated. Then using deuterium lamp, integrating sphere, precise stop and rail, an ultraviolent light source was developed, which has fixed structure of spectrum, but the irradiance can change continuously in long range. At last the light source’s performance was tested. The result shows that the irradiance between 0.278 and 2.8×10-7 μW·cm-2 was covered, and the stability was 0.93%/3 h. So the demand of calibration of irradiance was satisfied. It will help for measuring the surface uniformity of detector and the calibration of imaging systems..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1451 (2012)
Measurement of Night Sky Spectral Radiation and Analysis of Spectral Denoising
XU Ying-ying, JIN Wei-qi, MA Wen-wen, LU Li-gen, MU Sheng-bo, and NI Jun-xiong
In spectral radiation detection, spectral characteristics of the environment are completely different from standard light sources, so the output characteristics of optical imaging device is bound to bring greater error due to spectrum matching in imaging characteristic analysis. In the present paper, we measured moon-lIn spectral radiation detection, spectral characteristics of the environment are completely different from standard light sources, so the output characteristics of optical imaging device is bound to bring greater error due to spectrum matching in imaging characteristic analysis. In the present paper, we measured moon-light and star-light spectral radiation using a portable CCD fiber spectrometer, and analyzed spectral characteristics, which provided a reference to correctly evaluate the imaging performance of optical imaging device..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1456 (2012)
Monitoring Spatio-Temporal Spectral Characteristics of Leaves of Karst Plant during Dehydration Using a Field Imaging Spectrometer System
LIU Bo, TONG Qing-xi, ZHANG Li-fu, ZHANG Xia, YUE Yue-min, and ZHANG Bing
As the supplement of spaceborne and airborne imaging spectrometer system, field Imaging spectrometer system spans a very broad range of applications. Imaging spectrometer system of this new kind could provide vital information especially for which spaceborne or airborne remote sensing could not be competent, such as prAs the supplement of spaceborne and airborne imaging spectrometer system, field Imaging spectrometer system spans a very broad range of applications. Imaging spectrometer system of this new kind could provide vital information especially for which spaceborne or airborne remote sensing could not be competent, such as proximal detection of plant population, individual plant or plant organs for site-specific management in precision agriculture. A new self-developed imaging spectrometer system was utilized to monitor spatio-temporal dynamics of spectral changes of plant leaves in response to dehydration. The phenomenon of blue shift of red edge of plant leaves was successfully detected and visualized in the form of image series. The patterns of photochemical reflectance index(PRI) of leaves during dehydration were compared and confirmed by fluorescence parameter quantum yield. Our results show that FISS has good spectral and radiometric properties and could be used in quantitative researches and precise information mapping..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1460 (2012)
Characteristics of Rubidium Forward Degenerate Four-Wave Mixing(FDFWM) Influenced by the Matrix Effect of Chloride Brine in Graphite Furnace
WANG Jian, REN Zhao-yu, CHENG Xue-mei, MIAO Yi-zhu, CHEN Hao-wei, YIN Xun-li, WANG Li-qin, and BAI Jin-tao
Rb is mainly extracted from brine. The authors studied the matrix effect of chloride brine (NaCl,CaCl2,KCl and MgCl2) on FDFWM (Forward phase-matching degenerate four-wave mixing) of Rb in the graphite furnace. The Rb and other chloride brine concentrations dependences of FDFWM were investigated respectively. The resulRb is mainly extracted from brine. The authors studied the matrix effect of chloride brine (NaCl,CaCl2,KCl and MgCl2) on FDFWM (Forward phase-matching degenerate four-wave mixing) of Rb in the graphite furnace. The Rb and other chloride brine concentrations dependences of FDFWM were investigated respectively. The results indicate that with the increase in Rb concentration, FDFWM increases and reaches the highest at 80 ng·mL-1. With the concentration of Rb sample further increasing, the FDFWM intensity drops. It was also found that when the Rb concentration is low, FDFWM signal is suppressed by the chloride brine, and the suppressing effect gets stronger with the increase in the chloride brine concentration. However, when the Rb concentration is high, FDFWM signal is first enhanced and then suppressed with the increase in the chloride brine concentration. The Cl- interference and Rb ionization in the graphite furnace were employed to explain the experimental results. This work is of important meaning in extracting and analyzing Rb in brine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1466 (2012)
Measurement of Optical Parameters of Organic Solvents by THz Time-Domain Reflection Spectroscopy
LIU Chang, YUE Ling-yue, WANG Xin-ke, SUN Wen-feng, and ZHANG Yan
Four kinds of organic solvents, including positive hexane, liquid paraffin, ethyl alcohol, and water, were measured by using terahertz time-domain reflection spectroscopy. According the experiment models, two methods can be used to extract optical parameters. Refractive index and absorption coefficient for these four sFour kinds of organic solvents, including positive hexane, liquid paraffin, ethyl alcohol, and water, were measured by using terahertz time-domain reflection spectroscopy. According the experiment models, two methods can be used to extract optical parameters. Refractive index and absorption coefficient for these four solvents were extracted with two methods and were compared with the results obtained by transmission measurements, which verified that these methods are correct. This work solved the problem that the optical parameters of sample absorbing strongly terahertz cannot be measured and extracted by using terahertz time-domain transmission system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1471 (2012)
Effects of γ Irradiation and O2-Annealing on Optical Spectra of Bi Doped Cadmium Tungstate Crystal
LUO Cai-xiang, XIA Hai-ping, YU Can, ZHANG Yue-pin, and XU Jun
The Bi doped tungstate of cadmium crystals were O2-annealed at various temperature, and the absorption and emission spectra of O2-annealed Bi doped tungstate of cadmium crystals were investigated. The absorption intensity decreased, and the absorption side band was shifted to blue short wavelength as the increase of anThe Bi doped tungstate of cadmium crystals were O2-annealed at various temperature, and the absorption and emission spectra of O2-annealed Bi doped tungstate of cadmium crystals were investigated. The absorption intensity decreased, and the absorption side band was shifted to blue short wavelength as the increase of annealing temperature. The emissions at 528 nm and 1 078 nm were observed under excited by 373 and 980 nm, which they were attributed to the intrinsic emission of CdWO4 crystal and emission of Bi5+ ion, respectively. After the crystals were O2-annealed, the 528 nm emission intensity enhanced while the 1 078 nm intensity reduced. It was attributed to the transformation of Bi5+ to Bi3+ ions in the annealing process. After O2-annealed, the transmission of the crystal was enhanced obviously and the color of the crystal became weak. It is attributed to the decrease of oxygen vacancy (Vo) in crystal after the crystal was heated in O2 atmosphere. The 1 078 nm emission intensity reduced while the 528 nm intensity enhanced after the crystals were γ-irradiated. It may be due to the transormation of Bi5+ to Bi3+ ions through evolution of γ-irradiated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1476 (2012)
Study on Plasma Parameters in Diffuse Discharge with Semispherical Electrod by Optical Emission Spectrum
DONG Li-fang, TONG Guo-liang, SHEN Zhong-kai, LIU Liang, JI Ya-fei, and ZHAO Huan-huan
The diffuse discharge plasma in air was observed in a dielectric barrier discharge with two semispherical water electrodes. The variations of vibration temperature, rotation temperature, and average electron energy as the function of the applied voltage were studied by emission spectroscopy. The vibration temperature aThe diffuse discharge plasma in air was observed in a dielectric barrier discharge with two semispherical water electrodes. The variations of vibration temperature, rotation temperature, and average electron energy as the function of the applied voltage were studied by emission spectroscopy. The vibration temperature and the rotation temperature were calculated through the second positive band system (Ｃ ３Πｕ→Ｂ ３Πｇ) of N+2 and the first negative band system (Ｂ ２Σ＋ｕ→Ｘ ２Σ＋ｇ) of N+2 respectively. The average electron energy was studied by intensity ratio of 391.4 and 337.1 nm. It was found that the rotation temperature increases with the applied voltage increasing, while the vibration temperature and the electron energy decrease..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1480 (2012)
Study of Emission Spectra of N Atom Generated in Multi-Needle-to-Plate Corona Discharge
GE Hui, YU Ran, ZHANG Lu, MI Dong, and ZHU Yi-min
The emission spectra of nitrogen (N) atom produced by multi-needle-to-plate negative corona discharge in air were detected successfully at one atmosphere, and the excited transition spectral line at 674.5 nm with maximum value of relative intensity was selected to investigate the influences of air and electrical parameThe emission spectra of nitrogen (N) atom produced by multi-needle-to-plate negative corona discharge in air were detected successfully at one atmosphere, and the excited transition spectral line at 674.5 nm with maximum value of relative intensity was selected to investigate the influences of air and electrical parameters on N atom relative density. The results indicate that N atom relative density in ionization region increases with the increase in power; decreases with increasing discharge gap and relative humidity; and with the increase in N2 content, the relative density of N active atom firstly increases and then decreases. Under present experimental conditions, the maximum value of N atom relative density appears at the axial distance from needle point r=1 mm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1483 (2012)
Spectra Line Profile and Vibrational Temperature of Bright Dot and Dark Dot Discharge in a Dielectric Barrier Discharge
DONG Li-fang, GENG Yi-qing, YAN Dong-mei, JI Ya-fei, SHEN Zhong-kai, TONG Guo-liang, and LI Ben
The emission spectrum line shift and vibrational temperature of the bright dot and dark dot discharges, which are observed in the argon and air dielectric barrier discharge at high temperature for the first time were measured and compared. The line shift of the spectral line of the ArⅠ(2P2→1S5)is measured and the vibraThe emission spectrum line shift and vibrational temperature of the bright dot and dark dot discharges, which are observed in the argon and air dielectric barrier discharge at high temperature for the first time were measured and compared. The line shift of the spectral line of the ArⅠ(2P2→1S5)is measured and the vibrational temperature was calculated using by the emission spectral lines of the N2 second positive band system (C3Πu→B3Πg). The results show that the spectrum line shift of the bright dot discharge channel is larger than that of the dark dot channel, which indicates that the former has higher electron density compared to the latter, and the vibrational temperature of the dark dot discharge channel is higher than that of the bright dot discharge channel..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1487 (2012)
The Changing Process of Population Probability and Fluorescence Intensity in ErP5O14 Noncrystalline from 0 Second to Stabilization
CHEN Xiao-bo, CHEN Ying, LI Song*, YAO Wen-ting, and WU Zheng-long
The results of numerical simulation were compared respectively with and without considering the improved coefficient for the energy transfer process in ErP5O14 noncrystalline under 521.8, 450.0, 405.5 and 378.5 nm lights excitation. The results showed that it is essential to take the coefficient into calculation where The results of numerical simulation were compared respectively with and without considering the improved coefficient for the energy transfer process in ErP5O14 noncrystalline under 521.8, 450.0, 405.5 and 378.5 nm lights excitation. The results showed that it is essential to take the coefficient into calculation where energy transfer plays a key role. The relative fluorescence intensity ratios of 4I13/2→4I15/2 to 4I11/2→4I15/2 under 523.8, 450.0 and 378.5 nm lights excitation were 2.11, 2.82 and 2.99 times larger than that under 979.3nm light excitation respectively. There are obviously effective near-infrared (NIR) quantum cutting of 4I13/2→4I15/2 transition. The result indicates that ErP5O14 noncrystalline has potential application in the enhancement of conversion efficiency of germanium solar cells..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1490 (2012)
Gd-Doped Natural Thenardite∶Eu Photoluminescence Properties of Europium
Guzaliayi JUMAN, Tuerxun AIDILIBIKE, Aizitiaili ABULIZI, and Aierken SIDIKE
The authors prepared Na2SO4∶Eu, Gd, and Na2Gd2(SO4)4∶Eu phosphors by heating, the mixed powder of GdF3, EuF3 and natural mirabilite with muffle furnace at 1 000 ℃ for 30 min and continually heating it with microwave at 750 ℃ for 10 min. With increasing the concentrations of Gd ion, the 610 nm emission intensity due to The authors prepared Na2SO4∶Eu, Gd, and Na2Gd2(SO4)4∶Eu phosphors by heating, the mixed powder of GdF3, EuF3 and natural mirabilite with muffle furnace at 1 000 ℃ for 30 min and continually heating it with microwave at 750 ℃ for 10 min. With increasing the concentrations of Gd ion, the 610 nm emission intensity due to Eu3+ was strengthened. Gd3+ probably formed a bridge between substrate and the activator so that the energy is able to be transferred efficiently. The luminescence intensity, along with colorimetric purity, reaches the top with 21 mol% Gd3+ doping in the thenardite (Na2SO4∶Eu) lattices, eventually coming up the quenching effects of concentration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1496 (2012)
Study on the Effect of Temperature on the Conformation of Cross-Linked Collagen by Two-Dimensional Infrared Correlation Spectroscopy
CHEN Yi-hui, TIAN Hui-lin, LI Ji-heng, and LI Guo-ying
The Fourier transform infrared spectroscopy and two dimensional correlation analysis method were applied to study a denaturing process of uncross-linked collagen and cross-linked collagen during varying temperature. It was found that the intensity of typically characteristic absorptions of collagen decreased and its peThe Fourier transform infrared spectroscopy and two dimensional correlation analysis method were applied to study a denaturing process of uncross-linked collagen and cross-linked collagen during varying temperature. It was found that the intensity of typically characteristic absorptions of collagen decreased and its peak shifted to low frequency, The amide II central absorbance peak moved to a lower frequency by about ~10 cm-1, which indicated that the inter-chain hydrogen bonds which stabilized the triple helix conformation of collagen were disrupted during thermal denaturation, resulting in a conformational change. The intensity of auto-peak at 1 515 cm-1 was maximum, which suggested that the temperature had a big impact on amide II. In comparison with uncross-linked collagen, the intensity of cross-peaks of cross-linked collagen was weaker, which demonstrated that the effect of temperature on the structure of cross-linked collagen was smaller, and the thermal stability properties of collagen solution could be improved by cross-linking. While the order of second structure changes of cross-linked collagen was different. These fundamental data should provide available information for understanding the relationship between the structure and function of cross-linked collagen..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1500 (2012)
Study on Specificity of Noninvasive Glucose Measurements Based on Two-Dimensional Correlation Mid-Infrared Spectroscopy
ZHANG Wen, CAO Yu-zhen, LIU Rong, and XU Ke-xin
Glucose specificity is the premise of spectroscopic measurements of blood glucose concentration, and it is also paramount for feasibility study of a spectral measurement method. Two-dimensional correlation spectroscopy technology is widely used in many fields such as inter-/intra-molecular reaction, material phase tranGlucose specificity is the premise of spectroscopic measurements of blood glucose concentration, and it is also paramount for feasibility study of a spectral measurement method. Two-dimensional correlation spectroscopy technology is widely used in many fields such as inter-/intra-molecular reaction, material phase transition and information extraction because of its high resolution and effective Noda’s rule. In the present paper, the glucose specificity for noninvasive glucose measurements by mid-infrared spectra based on the 2D correlation spectroscopy was investigated. First, the feasibility of this method was validated by a series of in vitro experiments of glucose. Then the in vivo experiments of four volunteers were conducted and the characteristic information of glucose by mid-infrared spectra collected from human fingers was confirmed by 2D correlation spectroscopy analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1507 (2012)
Study on the Micro-Infrared Spectra and Origin of Polycrystalline Diamonds from Mengyin Kimberlite Pipes
YANG Zhi-jun, LIANG Rong, ZENG Xiang-qing, GE Tie-yan, AI Qun, ZHENG Yun-long, and PENG Ming-sheng
The natural polycrystalline diamonds from the Mengyin kimberlite pipes can be classified as the euhedral faceted polycrystalline diamonds and anhedral rounded polycrystalline diamonds. The results of micro-FTIR spectra characterization of the polycrystalline diamonds show that the concentration of nitrogen is low, varyThe natural polycrystalline diamonds from the Mengyin kimberlite pipes can be classified as the euhedral faceted polycrystalline diamonds and anhedral rounded polycrystalline diamonds. The results of micro-FTIR spectra characterization of the polycrystalline diamonds show that the concentration of nitrogen is low, varying from 16.69 to 72.81 microgram per gram and is different among different diamond grains or position in polycrystalline diamonds. The euhedral faceted polycrystalline diamonds are ⅠaAB type and have higher concentration of A-center defects than B-center defects. Most of the anhedral rounded polycrystalline diamonds are ⅠaAB type and have higher content of B-center defects. A minority of the anhedral rounded polycrystalline diamonds have C-center, A-center and B-center defects simultaneously. The polycrystalline diamonds probably originated from the relatively deeper mantle and were not formed in diamond nucleation stage, but in the diamond growth period or some special conditions after the diamond grains were formed already. Furthermore, the euhedral faceted polycrystalline diamonds were formed slightly later and the anhedral rounded polycrystalline diamonds were formed obviously earlier than the diamond single crystals from the Mengyin kimberlite pipes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1512 (2012)
Analysis of the Character of Film Decomposition of Starch Acetate (SA) Coated Urea by Infrared Spectrum
LI Dong-po, WU Zhi-jie, LIANG Cheng-hua, CHEN Li-jun, ZHANG Yu-lan, and NIE Yan-xia
The degradability characteristics of film with 4 kinds of starch acetate coated and inhibitors amended urea were analyzed by FTIR, which was purposed to supply theoretical basis for applying starch acetate coated urea fertilizers in farming. The result showed that the chemical component, molecule structure and materialThe degradability characteristics of film with 4 kinds of starch acetate coated and inhibitors amended urea were analyzed by FTIR, which was purposed to supply theoretical basis for applying starch acetate coated urea fertilizers in farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. The main peaks of the film degradation process were brought by the H—O, —OH, CO2, CO, —CH2, —CH3, C—O, C—O—H and C—O—C vibrancy in asymmetry and symmetry. In brown soil, the trend of absorbing value of the most high peak was 0＞15＞30＞60＞90＞120＞150＞310 d. The infrared spectra of 4 kinds of fertilizers were not different remarkably, and the film was comparatively slowly degraded before 15 d. But a majority of the film had been already degraded after 150 days. The main components of film materials were degraded fastest in 310 days. The speed of film degradation wasn’t more impacted by different inhibitors. The characteristic of starch acetate film degradation may be monitored entirely and degradation speed difference of the film could be represented through infrared spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1519 (2012)
Maturity Qualitative Discrimination of Small Watermelon Fruit
LI Yong-yu, ZHAO Hong-wei, CHANG Dong, and HAN Dong-hai
Dividing watermelons into two categories as not complete mature and fully mature by cluster analyzing the 10 indicators associated with maturity, the two modeling methods PCADA and PLSDA were used, and through the near-infrared spectroscopy, the maturity of small watermelon fruit JINGXIU was qualitatively determined. TDividing watermelons into two categories as not complete mature and fully mature by cluster analyzing the 10 indicators associated with maturity, the two modeling methods PCADA and PLSDA were used, and through the near-infrared spectroscopy, the maturity of small watermelon fruit JINGXIU was qualitatively determined. The PCADA model is the best. Modeling at the top position is better than that of the equatorial parts of the melon. The two models both have a miscarriage of justice, and exists the same sample with a miscarriage of justice. Fruit samples of different physical and chemical composition and structure will have an impact on the spectral information, resulting in miscarriage of justice. Near-infrared diffuse transmittance technique can get better results in detection of small watermelon maturity. But the prediction model should be established to select the appropriate parts of the spectrum acquisition and modeling methods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1526 (2012)
The Utility Research on NIR Diffuse Reflectance and Transmittance Measurements Mode in Authenticity Identification of Maize Population Samples
TANG Xing-tian, WU Wen-jin, GUO Ting-ting, JIA Shi-qiang, YAN Yan-lu, and AN Dong
In the present paper, the spectral measurements of maize population samples were researched so as to identify their authenticity. Diffuse reflectance and transmittance measure modes were used to collect spectral data of 8 maize varieties. DPLS-DA was used to compress pretreated data. The recognition models of eight maiIn the present paper, the spectral measurements of maize population samples were researched so as to identify their authenticity. Diffuse reflectance and transmittance measure modes were used to collect spectral data of 8 maize varieties. DPLS-DA was used to compress pretreated data. The recognition models of eight maize varieties were built based on biomimetic pattern recognition (BPR). The average correct recognition rate and average correct rejection rate of identification models built by two modes were calculated. The average recognition rate and rejection rate of diffuse reflectance method reached 94.50% and 96.71%, and those of transmittance method reached 98.5% and 98.00%, respectively. Both of them met the requirements of maize preliminary screening., and the recognition rate and rejection rate of transmittance method are higher than diffuse reflectance method by 4% and 1.3% respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1531 (2012)
Infrared Spectroscopy Analysis of SF6 Using Multiscale Weighted Principal Component Analysis
PENG Xi, WANG Xian-pei, and HUANG Yun-guang
Infrared spectroscopy analysis of SF6 and its derivative is an important method for operating state assessment and fault diagnosis of the gas insulated switchgear (GIS). Traditional methods are complicated and inefficient, and the results can vary with different subjects. In the present work, the feature extraction metInfrared spectroscopy analysis of SF6 and its derivative is an important method for operating state assessment and fault diagnosis of the gas insulated switchgear (GIS). Traditional methods are complicated and inefficient, and the results can vary with different subjects. In the present work, the feature extraction methods in machine learning are recommended to solve such diagnosis problem, and a multiscale weighted principal component analysis method is proposed. The proposed method combines the advantage of standard principal component analysis and multiscale decomposition to maximize the feature information in different scales, and modifies the importance of the eigenvectors in classification. The classification performance of the proposed method was demonstrated to be 3 to 4 times better than that of the standard PCA for the infrared spectra of SF6 and its derivative provided by Guangxi Research Institute of Electric Power..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1535 (2012)
Detection and Analysis of Alcohol Near-Infrared Spectrum in Vitro and Vivo Based on Wavelet Transform
LUO Si-te, LI Zeng-yong, ZHANG Ming, and CHEN Guo-qiang
The near-infrared spectroscopy (NIRS) signals of alcohol in vivo are always contaminated by noise. In the present study, wavelet analysis was used to eliminate noise and thereby detecting the NIRS signals of alcohol in vivo. In soft and hard threshold function, the spectral signals were de-noised by default threshold, The near-infrared spectroscopy (NIRS) signals of alcohol in vivo are always contaminated by noise. In the present study, wavelet analysis was used to eliminate noise and thereby detecting the NIRS signals of alcohol in vivo. In soft and hard threshold function, the spectral signals were de-noised by default threshold, Birge-Massart threshold and mini&max threshold respectively. Signal noise ratio (SNR) and root mean square error (RMSE) method were used to evaluate the effects of the de-noising. The results show that the default threshold de-noising has the best effects. Therefore, the default threshold de-noising was chosen to perform de-noising analysis in vivo and in vitro. Our result shows that the wavelet transform de-noising is effective in removing noise from NRS signals of alcohol in vivo. With different alcohol concentration, the de-noising spectrua can show evident absorption peaks. Wavelet analysis is an effective method in the non-invasive alcohol testing and quantitative analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1541 (2012)
Qualitative Detection of Bottled Vinegar Based on NIR Spectroscopy Technique
SONG Hai-yan, QIN Gang, and LIU Hai-qin
To evaluate the applicability of non-invasive near infrared reflectance (NIR) spectroscopy for detection of bottled vinegar, transmission spectra of bottled vinegar samples were obtained and compared with the spectra obtained by using cell detection method, where samples were titrated in the fixed liquid cell with a 1.To evaluate the applicability of non-invasive near infrared reflectance (NIR) spectroscopy for detection of bottled vinegar, transmission spectra of bottled vinegar samples were obtained and compared with the spectra obtained by using cell detection method, where samples were titrated in the fixed liquid cell with a 1.0 mm light path length. The result shows that, the spectra obtained by the two different methods have obvious differences in the near infrared region. Firstly, the spectra obtained by using bottled detection method have no absorption peak at 1 480 and 1 900 nm, and furthermore, it has absorption peak at 1 660 nm. Secondly, the max. absorbance value of bottled detection is less than 4, while with the cell detection it is near 6. It indicates that glass packaging has influence on the detection of bottled vinegar. The 1st derivative method was put forward to eliminate this influence, and then qualitative analysis model was obtained by using principal component analysis-artificial neural net work. The precision of prediction result achieved 100%. This research shows that 1st derivative can eliminate the influence of glass packaging, and realize the qualitative analysis of bottled vinegar..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1547 (2012)
Recognition of Corn Seeds Based on Pattern Recognition and Near Infrared Spectroscopy Technology
LIU Tian-ling, SU Qi-ya, SUN Qun, and YANG Li-ming
Pattern recognition technology and data mining methods have become a hot topic in chemometrics. Near infrared (NIR) spectroscopic analysis has been widely used in spectrum signal processing and modeling due to its advantages of quickness, simplicity and nondestructiveness. Based on five different methods of pattern recPattern recognition technology and data mining methods have become a hot topic in chemometrics. Near infrared (NIR) spectroscopic analysis has been widely used in spectrum signal processing and modeling due to its advantages of quickness, simplicity and nondestructiveness. Based on five different methods of pattern recognition, namely the locally linear embedding (LLE), wavelet transform (WT), principal component analysis (PCA), partial least squares (PLS) and support vector machine (SVM), the pattern recognition system for corn seeds is proposed using NIR technology, and applied to classification of 108 hybrid samples and 178 female samples for corn seeds. Firstly, we get rid of noise or reduce the dimension using LLE, WT, PCA and PLS, and then use SVM to identify two-class samples. In the meantime, 1-norm SVM is the method of direct classification and identification. Experimental results for three different spectral regions show that the performances of three methods, i.e. PCA+SVM, LLE+SVM, PLS+SVM, are superior to WT+SVM and 1-norm SVM methods, and obtain a high classification accuracy, which indicates the feasibility and effectiveness of the proposed methods. Moreover, this investigation provides the theoretical support and practical method for recognition of corn seeds utilizing near infrared spectral data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1550 (2012)
Research on Detection Method of Adulterated Olive Oil by Raman Spectroscopy and Least Squares Support Vector Machine
ZHANG Ying-qiang, DONG Wei, ZHANG Bing, and WANG Xiao-ping
For the purpose of the authentication of sorts as well as the prediction of contents of the oils which were adulterated into olive oil, 117 olive oil samples adulterated with sunflower seed oil, soybean oil and corn oil were detected by Raman spectroscopy, and least squares support vector machine (LS-SVM) based on multFor the purpose of the authentication of sorts as well as the prediction of contents of the oils which were adulterated into olive oil, 117 olive oil samples adulterated with sunflower seed oil, soybean oil and corn oil were detected by Raman spectroscopy, and least squares support vector machine (LS-SVM) based on multiple iterative optimization was used to identify the type of the adulterant oil, and the composite recognition rate was 97%. In addition, methods such as LS-SVM, ANNs and PLSR were used to build the Raman spectra calibration model of the adulterant oil (sunflower seed oil, soybean oil and corn oil) contents respectively, the results indicated that LS-SVM had the best predictive performance, and the root mean square error of prediction (RMSEP) ranged from 0.007 4 to 0.014 2. Research results showed the method based on Raman spectroscopy and LS-SVM was accurate, fast, simple and non-destructive for adulterated olive oil detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1554 (2012)
Poly(Allylamine)-Stabilized Colloidal Copper Nanoparticles: Synthesis and Their SERS Activities
WANG Yan-fei, XIAO Zhan-min, and ZHANG Chun-guang
Poly(allylamine)-stabilized spherical and rod-shaped copper nanoparticles were synthesized by a simple chemical reaction. The synthesis was performed by the reduction of copper(Ⅱ) salt with hydrazine in aqueous solution under atmospheric air in the presence of poly(allylamine) (PAAm) capping agent. Besides providing loPoly(allylamine)-stabilized spherical and rod-shaped copper nanoparticles were synthesized by a simple chemical reaction. The synthesis was performed by the reduction of copper(Ⅱ) salt with hydrazine in aqueous solution under atmospheric air in the presence of poly(allylamine) (PAAm) capping agent. Besides providing long-term stability to the nanoparticles by preventing particle agglomeration, polymer capping agents such as PAAm make the particles dispersible in aqueous solution. Noteworthy advantages of the synthetic method include its production of water dispersible nanoparticles at room temperature without inert atmosphere, making the synthesis more environmentally friendly. The resulting copper nanoparticles were investigated by UV-Vis spectroscopy and transmission electron microscopy. The authors found that several factors, including the amount of NaOH solution, concentration of PAAm, and reaction time, affect the composition, size, morphology, and degree of agglomeration of the resulting copper nanoparticles. The amount of NaOH in the reaction is crucial for the synthesis to result in either pure copper or copper oxide-containing copper nanoparticles as well as to produce the highest possible yield of copper nanoparticles. In addition, the reaction time and concentration of PAAm play key roles in controlling the size and shape of the nanoparticles, respectively. The resulting colloidal copper nanoparticles exhibit large surface-enhanced Raman spectroscopy (SERS) signals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1559 (2012)
Research on Using 3-D Fluorescence Spectroscopy-Wavelet Transform-PSO for Rapid Discrimination of Compositions of Phytoplankton Population
DUAN Ya-li, SU Rong-guo, SHI Xiao-yong, and ZHANG Cui
Three-dimensional fluorescence of 17 red tide algae species that belong to 13 genera of five divisions was measured by fluorescence excitation-emission matrix spectroscopy. And 2-D wavelet db7 was selected to decompose the spectra at different levels to choose the alternative characteristic spectra. Based on the norm rThree-dimensional fluorescence of 17 red tide algae species that belong to 13 genera of five divisions was measured by fluorescence excitation-emission matrix spectroscopy. And 2-D wavelet db7 was selected to decompose the spectra at different levels to choose the alternative characteristic spectra. Based on the norm reference spectra constructed by cluster analysis, the linear regression model was solved by particle swarm optimization (PSO) algorithm and the discrimination method was established at the division and genus level. Some samples were tested: for single algal samples, and the correct discrimination ratios (CDRs) were 96.1% and 73.6%, respectively; For simulative mixed algal samples, when the dominance were 60%, 75%, 80% and 90% of the total biomass, the CDRs of the dominant algae were 86.7%, 96.9%, 98.7% and 99.4% with the average relative contents of 62.6%, 72.7%, 76.0% and 81.6%, respectively at the division level. And the CDRs were 51.0%, 68.9%, 72.0%, and 78.8% at the genus level, respectively. For 364 actual mixture samples, the CDRs of the dominant species (75%) were 99.4% at the division level and 75.9% at the genus level . For the particular field samples from mesocosm experiment and corrected from Jiaozhou Bay, results showed that the method can be used to realize the identification of red tide algae population and estimate the relative abundance of different classes, especially between diatoms and dinoflagellates..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1562 (2012)
The Quantification of Gemifloxacin by Fluorescence Quenching Method Using Chitosan-Coated CdTe Quantum Dots
ZHONG Wen-ying, WANG Yan, HUANG Bin, and SHU Chang
Chitosan-coated CdTe quantum dots can reduce QDs toxicity and enhance its stability in aqueous solution. Chitosan-coated CdTe QDs were used as fluorescence probes to determine Gemifloxacin on the basis of fluorescence quenching method. The results indicated that the relative fluorescence intensity was linearly proportiChitosan-coated CdTe quantum dots can reduce QDs toxicity and enhance its stability in aqueous solution. Chitosan-coated CdTe QDs were used as fluorescence probes to determine Gemifloxacin on the basis of fluorescence quenching method. The results indicated that the relative fluorescence intensity was linearly proportional to the Gemifloxacin concentration in the range of 3.46×10－9～3.46×10－7 g·L-1 with a linear fitting equation of F0/F=1.0637+0.016 7c(g·L-1) and the RSD was 2.7%. On the basis of fluorescence quenching method theory, it was concluded that the interaction between QDs and Gemifloxacin was a kind of static quenching through hydrogen bonding and Van der Waals force, and the binding sites value was 0.8. This method with high sensitivity and broad linear range provided a new approach to determining Gemifloxacin..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1570 (2012)
3D-EEM Fluorescence Characteristics of Different Fraction of Dissolved Organic Matter in Landfill Leachate
JIA Chen-zhong, WANG Yan-xin, ZHANG Cai-xiang, and QIN Qiao-yan
Three-dimensional excitation emission matrix fluorescence spectroscopy (3D-EEM) was applied to analyze the fluorescence characterization of dissolved organic matter in landfill leachate. The results showed that fulvic-like, tryptophan-like and humic acids-like matters were the main compounds in landfill leachate. A numThree-dimensional excitation emission matrix fluorescence spectroscopy (3D-EEM) was applied to analyze the fluorescence characterization of dissolved organic matter in landfill leachate. The results showed that fulvic-like, tryptophan-like and humic acids-like matters were the main compounds in landfill leachate. A number of UV fulvic-like matters led to ineffective biodegradation of leachate. HOA contained more UV fulvic-like and less Vis fulvic-like, by contrary to HIA; HIN was mainly composed of UV fulvic-like and Vis fulvic-like matters; HOB, HIB and HIN had more intense fluorescence signal, whose fluorescence peaks occurred in the region of fulvic-like, tryptophan-like and humic acids-like. This was similar to the original leachate as well as HON which had relatively weak fluorescence signal. Moreover, different fractions had different fluorescence signal intensity in different regions. HOB and HIB had more intense signal in the region of UV fulvic-like. HIN had more intense signal in the region of UV fulvic-like and Vis fulvic-like. HON had moderately intense signal in the whole region. HOA and HIA had relatively weak fluorescence signal..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1575 (2012)
Comparison of Quasi-Continuous and Continuous Tunable Diode Laser Absorption Spectroscopy for Gas Detection
DU Zhen-hui, GAO Dong-yu, QI Ru-bin, XU Xiao-bin, and JIAO Meng
The theoretical analysis of the direct absorption spectroscopy, the continuous modulation spectroscopy and the quasi-continuous modulation spectroscopy was shown and the corresponding experiments were carried out in order to choose the adequate scheme of the laser modulation spectroscopy to satisfy different requiremenThe theoretical analysis of the direct absorption spectroscopy, the continuous modulation spectroscopy and the quasi-continuous modulation spectroscopy was shown and the corresponding experiments were carried out in order to choose the adequate scheme of the laser modulation spectroscopy to satisfy different requirements of the detection. CO2 gas with different concentrations was detected under the same experimental conditions by using the three different modulation techniques with the same laser. Technical characteristics, signal features and detection limits were compared respectively. Results showed that the detection limit of the quasi-continuous modulation spectroscopy was approaching to that of the continuous modulation spectroscopy. However the linear distortion of the detection signal was obvious, because of the effects of laser energy intermittent and parasitic amplitude modulation on the line shape. Therefore the quasi-continuous modulation spectroscopy is not suitable for the pressure and flow measurements, which closely depend on the line shape. This work has provided reference for selections of the laser modulation spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1580 (2012)
Spectral Characteristics of Dissolved Organic Matter Released during the Metabolic Process of Small Medusa
GUO Dong-hui, YI Yue-yuan, ZHAO Lei, and GUO Wei-dong
The metabolic processes of jellyfish can produce dissolved organic matter (DOM) which will influence the functioning of the aquatic ecosystems, yet the optical properties of DOM released by jellyfish are unknown. Here we report the absorption and fluorescence properties of DOM released by a medusa species Blackfordia vThe metabolic processes of jellyfish can produce dissolved organic matter (DOM) which will influence the functioning of the aquatic ecosystems, yet the optical properties of DOM released by jellyfish are unknown. Here we report the absorption and fluorescence properties of DOM released by a medusa species Blackfordia virginica during a 24 h incubation experiment. Compared with the control group, an obvious increase in the concentrations of dissolved organic carbon (DOC), absorption coefficient (a280) and total dissolved nitrogen (TDN) was observed in incubation group. This clearly demonstrated the release of DOM, chromophoric DOM (CDOM) and dissolved nutrients by B. virginica which feed on enough of Artemia sp. before the experiment. The increase in spectral slope ratio (SR) and decrease in humification index (HIX) indicated that the released DOM was less-humified and had relatively lower molecular weight. Parallel factor analysis (PARAFAC) decomposed the fluorescence matrices of DOM into three humic-like components (C1-C3) and one protein-like component (C4). The Fmax of two components (C2: <250， 295/386 nm; C4: 275/334 nm) with the emission wavelength < 400 nm increased significantly during the metabolic process of B. virginica. However, the Fmax of the other two components with the emission wavelength >400 nm showed little changes. Thus, we suggested a zooplankton index (ZIX) to trace and characterize the DOM excreted by metabolic activity of zooplankton, which is calculated as the ratio of the sum of Fmax of all fluorescence components with the emission wavelength <400 nm to the sum of Fmax of the other components with the emission wavelength >400 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1584 (2012)
Spectroscopy of Ag(Ⅰ), Cd (Ⅱ) Complexes with 4-Mercaptopyridine
SHI Xiu-min, JIANG Rui, SONG Wei, and ZHAO Bing
In the present article, two kinds of metal-organic coordination compounds were synthesized between 4-mercaptopyridine (4-MPy) and nitrate of Ag(Ⅰ) and Cd(Ⅱ) by a general solution reaction and evaporation. 4-mercaptopyridine and two transition metal complexes were investigated by means of infrared, Raman and ultravioletIn the present article, two kinds of metal-organic coordination compounds were synthesized between 4-mercaptopyridine (4-MPy) and nitrate of Ag(Ⅰ) and Cd(Ⅱ) by a general solution reaction and evaporation. 4-mercaptopyridine and two transition metal complexes were investigated by means of infrared, Raman and ultraviolet-visible spectroscopic techniques, respectively. Assignments of the main FTIR and Raman bands were carried out in detail. The relationship between those characteristic bands and the structure of ligands and coordination compounds was discussed. In the FTIR spectra, the co-vibration absorption band of ν(CC) and ν(CN), for 4-MPy at 1 459 cm-1 blue-shifted to 1 464 cm-1 for both the metal-organic coordination compounds, respectively. The Raman spectra, for the two coordination compounds, at 1 004 and 1 008 cm-1, which can be assigned to ring breathing vibration, at 1 617 and 1 615 cm-1, which can be assigned to ring flex vibration, and at 720 and 720 cm-1, which can be assigned to the composite vibration of β(C—C) and ν(C—S) are similar, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1588 (2012)
The Study of Spectral Characteristics of Several Organophosphate Pesticides
CHEN Chao, CHEN Guo-qing, GAO Shu-mei, KONG Fan-biao, LI Run, and HUANG Qi-feng
Using Edinburgh FLS920P spectrometer, the authors obtained the UV-visible spectrum and fluorescence spectrum of parathion, metaphos and isocarbophos in their solution of methanol and ethanol respectively，and discussed their spectral characteristics and their mechanisms. Results show that they all have obvious absorptioUsing Edinburgh FLS920P spectrometer, the authors obtained the UV-visible spectrum and fluorescence spectrum of parathion, metaphos and isocarbophos in their solution of methanol and ethanol respectively，and discussed their spectral characteristics and their mechanisms. Results show that they all have obvious absorption and fluorescence under the excitation of ultraviolet. The absorption peaks of parathion, metaphos and isocarbophos in their methanol and ethanol solution respectively are at 304 nm/298 nm， 304 nm/304 nm and 286 nm/286 nm. The peak wavelengths of fluorescence are at 404 nm/403 nm, 407 nm/402 nm and 423 nm/415 nm, fitting fluorescence characteristics of conjugated aromatic compounds that the peak will have red shift with the increasing solvent polarity. The results may contribute to the application of spectral technique in the distinction of pesticides and detection of residues of pesticides in the area of food security supervision..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1592 (2012)
Research on Fast Experimental Measurement Method for Atmosphere Downward Long-Wave Radiance
HU Ju-yang, TANG Shi-hao, DONG Li-xin, and LI Xiang
Direct measurement of the sky radiation in the direction of a special zenith angle as the average downward radiation is the fastest instantaneous downward radiation measurement. But this method has not been widely used, because there is no accurate method for determining special zenith angle. The present paper analyzedDirect measurement of the sky radiation in the direction of a special zenith angle as the average downward radiation is the fastest instantaneous downward radiation measurement. But this method has not been widely used, because there is no accurate method for determining special zenith angle. The present paper analyzed the special angle with the variation of the aerosol optical thickness and atmospheric temperature and humidity through simulation by radiative transfer model. The results show that the special angles will be affected none by aerosols in clear skies, very little by atmospheric temperature, but significantly by atmospheric water vapor content. Therefore, the special angle could be determined only by atmospheric water vapor content in downward radiance infrared spectroscopy measurements in clear sky conditions. The downward radiation measurements results in western desert region indicate that the special angles determined by local atmospheric water vapor content are the same as experimental results. Besides, the error caused by taking the radiance at the special angle as the integral radiance meets the accuracy requirements. Accordingly, this fast measurement method can be widely used in field experiments while the special angle can be determined by atmospheric water vapor of the study area, since it can measure instantaneous downward radiance conveniently and accurately..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1596 (2012)
A Modulation Method to Improve the Signal-to-Noise Ratio of Internal Virtual Hyperspectrum of Body Surface
LIN Ling, WU Hong-jie, LI Gang, ZHANG Bao-ju, and WU Jin-cheng
Virtual internal hyperspectrum of body surface which can express and properly mix the information of skin’s composition and structure was expected to apply in the human disease quick-diagnosis, but the weak detected signal was easily impacted by ambient light and dark current from the instrument, so square wave modulatVirtual internal hyperspectrum of body surface which can express and properly mix the information of skin’s composition and structure was expected to apply in the human disease quick-diagnosis, but the weak detected signal was easily impacted by ambient light and dark current from the instrument, so square wave modulated by chopper disk was proposed to resolve this issue. First, we built the experiment platform, and selected both laser and bromine tungsten lamp as the light source, then compared the virtual hyperspectrum of non-modulated and modulated light on human arm in the environment with artificial interference, and demodulated the modulated signal by FFT method. The experiment result showed that modulation method could effectively eliminate the impact brought by environmental light and dark current and improve the signal to noise ratio (SNR)， suggesting a new approach to detect human’s weak optical signals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1601 (2012)
The Research on Multi-Spectral Fitting of LED Spectrum Tunable Light Source
NI Jun-xiong, BAI Ting-zhu, and XU Ying-ying
Using a number of different spectral LED cells, the spectra of several typical spectral light source were fitted successfully. The research focuses on how to find the needed spectral distribution and the least number of LEDs by using the target spectrum to go. Furthermore the result is used to judge and improve the obtUsing a number of different spectral LED cells, the spectra of several typical spectral light source were fitted successfully. The research focuses on how to find the needed spectral distribution and the least number of LEDs by using the target spectrum to go. Furthermore the result is used to judge and improve the obtained original fitting model. Simulate The target spectrum obtained by the actual measurement was simulated and preferable prospective result was obtained..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1606 (2012)
Quantitative Inversion of Rock SiO2 Content Based on Thermal Infrared Emissivity Spectrum
YANG Hang, ZHANG Li-fu, HUANG Zhao-qiang, ZHANG Xue-wen, and TONG Qing-xi
The present paper used the emissivity of non-processed rocks measured by M304, a hyperspectral Fourier transform infrared (FTIR) spectroradiometer, and SiO2 content by the X-ray fluorescence spectrometry. After continuum removal and normalization, stepwise regress method was employed to select the feature bands of rockThe present paper used the emissivity of non-processed rocks measured by M304, a hyperspectral Fourier transform infrared (FTIR) spectroradiometer, and SiO2 content by the X-ray fluorescence spectrometry. After continuum removal and normalization, stepwise regress method was employed to select the feature bands of rocks emissivity. And then quantitative relationship between SiO2 content and continuum removal emissivity of feature bands was analysed. Based on that, by comparing twelve SiO2 indices models, the optimal model for predicting SiO2 content was built. The result showed that the SiO2 indices can predict SiO2 content efficiently, and especially the normalization silicon dioxide index (NSDI) about 11.18 and 12.36 μm is the best; compared with regression models, NSDI is simpler and has higher practicality; the result has an important application value in rock classification and SiO2 content extraction with high precision..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1611 (2012)
Study on Hyperspectral Response to Surface Alteration by Oil and Gas Microseepage under Loess Area
CHEN Sheng-bo, ZHAO Liang, and WANG Jin-nian
The present takes the Qingyang, Gansu as an example, based on the mechanism of oil-gas microseepage, the spectra of the loess samples were measured, and the contents of carbonate minerals, clay minerals, Fe2+ and Fe3+, were analyzed. From their contents, it was shown that the carbonate mineralization and the red fadingThe present takes the Qingyang, Gansu as an example, based on the mechanism of oil-gas microseepage, the spectra of the loess samples were measured, and the contents of carbonate minerals, clay minerals, Fe2+ and Fe3+, were analyzed. From their contents, it was shown that the carbonate mineralization and the red fading phenomenon are obvious for the known oil-gas field. Meanwhile, the parameters of absorption spectra of the loess samples were identified after the continuum was removed. The multiple regression analysis between the spectrum parameters (independent variables) and the mineral contents (the dependent variables) was implemented. The results indicate that the absorption depth is more sensitive. Thus, by their spectrum absorption parameters, 14 spectra of loess samples were clustered into two groups: samples in the known oil-gas field and unknown oil-gas field..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1616 (2012)
Study on Varieties Identification of Kentucky Bluegrass Using Hyperspectral Imaging and Discriminant Analysis
XIAO Bo, MAO Wen-hua, LIANG Xiao-hong, ZHANG Li-juan, and HAN Lie-bao
Hyperspectral images of six varieties of Kentucky bluegrass were acquired using hyperspectral imager (550-1 000 nm) and the leaf spectral properties were extracted. Wilks’ lambda stepwise method was used and 9 optimal wavelengths were selected from the original 94 wavelengths and the discriminant models for varieties iHyperspectral images of six varieties of Kentucky bluegrass were acquired using hyperspectral imager (550-1 000 nm) and the leaf spectral properties were extracted. Wilks’ lambda stepwise method was used and 9 optimal wavelengths were selected from the original 94 wavelengths and the discriminant models for varieties identification of Kentucky bluegrass were built based on Fisher’s linear discriminant function. The results showed that the Fisher’s linear discriminant model with 9 wavelengths achieved classification accuracies of 100% for both training and testing samples. While for the models with three wavelengths and six wavelengths, classification accuracies reached 83.3% and 96.7% for the testing samples, respectively. It indicates that hyperspectral images combined with discriminant analysis might be a good method to identify the varieties of Kentucky bluegrass..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1620 (2012)
Improving Signal to Noise Ratio of Spectroscopy for Tongue Inspection by Reflectivity Normalization Method
ZHAO Jing, LI Zhe, LI Gang, LIN Ling, Jean X. Gao, and HAN Guang-lin
In order to solve the problem that the collected spectrum was influenced seriously by the operation method, improve the instrument sensitivity and enhance the differences between samples, reflectivity normalization method was used for data preprocessing in the present article. First, the reflect spectrum of tongue was In order to solve the problem that the collected spectrum was influenced seriously by the operation method, improve the instrument sensitivity and enhance the differences between samples, reflectivity normalization method was used for data preprocessing in the present article. First, the reflect spectrum of tongue was collected, then the reflectivity and the normalized reflectivity of the samples were compared, and it was found that reflectivity normalization method can eliminate the impact brought by the collection from different distance. At the same time, the classification results between the reflectivity and the normalization reflectivity of the different samples were compared, and the results showed that the reflectivity normalization method can enhance differences between the samples and enhance model’s robustness and prediction ability of subsequent disease screening..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1624 (2012)
Advances in the Research on Hyperspectral Remote Sensing in Biodiversity and Conservation
HE Cheng, FENG Zhong-ke, YUAN Jin-jun, WANG Jia, GONG Yin-xi, and DONG Zhi-hai
With the species reduction and the habitat destruction becoming serious increasingly, the biodiversity conservation has become one of the hottest topics. Remote sensing, the science of non-contact collection information, has the function of corresponding estimates of biodiversity, building model between species diversiWith the species reduction and the habitat destruction becoming serious increasingly, the biodiversity conservation has become one of the hottest topics. Remote sensing, the science of non-contact collection information, has the function of corresponding estimates of biodiversity, building model between species diversity relationship and mapping the index of biodiversity, which has been used widely in the field of biodiversity conservation. The present paper discussed the application of hyperspectral technology to the biodiversity conservation from two aspects, remote sensors and remote sensing techniques, and after, enumerated successful applications for emphasis. All these had a certain reference value in the development of biodiversity conservation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1628 (2012)
The Polarization Characteristics Distribution and Correction Method of the Polarization Coupling Error in Ocean Remote Sensing System
GAO Jun, WANG Shu-peng, GU Xing-fa, YU Tao, and FANG Li
With the development of the quantitative researches using ocean color remote sensing data sets, study on reducing the uncertainty of the response of the ocean color remote sensors to the polarization characteristics of the target has been attracting more and more attention recently. Taking MODIS as an example, the polaWith the development of the quantitative researches using ocean color remote sensing data sets, study on reducing the uncertainty of the response of the ocean color remote sensors to the polarization characteristics of the target has been attracting more and more attention recently. Taking MODIS as an example, the polarization distribution in the whole field of view was analyzed. For the atmosphere path radiance and the apparent radiance considering the coupling between ocean surface and atmosphere, the polarization distribution has a strong relation with the imaging geometry. Compared to the contribution of the polarization from the rough sea surface, the contribution from the atmosphere is dominated. Based on the polarization characteristics in the field of view, the influence of the polarization coupling error on the quality of the satellite data was studied with the assumption of different polarization sensitivities. It was found that errors due to polarization sensitivity in the field of view are lower than water leaving radiance only when the polarization sensitivity is less than 2%. And in this case it can meet the need of the retrieval of water leaving radiative products. The method of the compensation for the polarization coupling error due to the atmosphere is proposed, which proved to be effective to improve the utilization of satellite data and the accuracy of measured radiance by remote sensor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1633 (2012)
Monitoring Gas Concentration from Carbon Emissions by Remote Sensing
WANG Li-wen, and WEI Ya-xing
Global climate warming has become the focus question of international global climate change research, and is an important factor influencing world economy, political situation, and ecological environment. Produced carbon emission gases such as CO2, CH4, N2O, etc. caused by human activity are the main reason for global Global climate warming has become the focus question of international global climate change research, and is an important factor influencing world economy, political situation, and ecological environment. Produced carbon emission gases such as CO2, CH4, N2O, etc. caused by human activity are the main reason for global warming. In order to forecast future climate change and construct accurate carbon cycle model, monitoring accuracy of gas concentration from carbon emission must be improved. In the present paper, the newest progress in the international research results about monitoring gas concentration from carbon emissions by remote sensing was considered, monitoring method for carbon emissions was introduced, and remotely sensed monitoring technology about gas concentration from carbon emissions (including thermal infrared, sun spectrum, active remote sensing monitoring technology) was stated. In detail, several present and future satellite sensors were introduced (including TOVS, AIRS, IASI, SCIAMACHY, GOSAT, OCO, A-SCOPE and ASCENDS), and monitoring results achieved by these sensors were analyzed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1639 (2012)
Retrieval of Dust Fraction of Atmospheric Aerosols Based on Spectra Characteristics of Refractive Indices Obtained from Remote Sensing Measurements
WANG Ling, LI Zheng-qiang, LI Dong-hui, LI Kai-tao, TIAN Qing-jiu, LI Li, ZHANG Ying, Lv Yang, and GU Xing-fa
Mineral dust is an important chemical component of aerosol, which has a significant impact on the climate and environmental changes. The spectral behavior of aerosol refractive indices at four wavelengths from 440 to 1 020 nm was analyzed based on one year observation obtained from Beijing AERONET site. The real parts Mineral dust is an important chemical component of aerosol, which has a significant impact on the climate and environmental changes. The spectral behavior of aerosol refractive indices at four wavelengths from 440 to 1 020 nm was analyzed based on one year observation obtained from Beijing AERONET site. The real parts of refractive index (n) in each band did not differ greatly, however the imaginary parts (k) showed a significant difference due to the absorption of mineral dust in aerosol. From 440 to 670 nm k decreased rapidly, while from 670 to 1 020 nm featured a lower, constant value. Accordingly, k(440 nm) could be considered separately with other three bands. Hence, we added mineral dust into the currently used three-component aerosol chemical model to form a new four-component model (i.e. BC, AS, dust and water) which is more suitable to represent the aerosol chemical composition. Then we presented a method to retrieve dust content in aerosols using this four-component model and refractive indices obtained from the sunphotometer measurements. Finally the dust content in aerosol was investigated under different weather conditions, i.e. clear, haze and dust in Beijing. The results showed that volume fractions of the dust component were 88%, 37% and 48% for clear, hazy and dusty day respectively, which was consistent with the coarse mode proportion in aerosols calculated from aerosol size distributions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1644 (2012)
Preparation and Performance of Controlled-Release Tablets of Sasanquasaponin-Casein
LIU Xiao-zhen, YANG Jun-hua, SONG Ling-ling, SONG Yue-xing, LAI Zhong-fan, and ZHAI Li
The controlled-release tablets of sasanquasaponin (SQS)-casein were prepared by using SQS, casein and guar gum as the main drug and accessory materials respectively. The method of determination of SQS in the controlled-release tablets of SQS-casein, and the effects of release media on the release rate and IR spectra ofThe controlled-release tablets of sasanquasaponin (SQS)-casein were prepared by using SQS, casein and guar gum as the main drug and accessory materials respectively. The method of determination of SQS in the controlled-release tablets of SQS-casein, and the effects of release media on the release rate and IR spectra of the controlled-release tablets of SQS-casein were studied, respectively. The release rate curve of the controlled-release tablets of SQS-casein was fitted as zero order, one order and Higuchi equation. The recovery was 98.59% when the content of SQS in the controlled-release tablets of SQS-casein in phosphate buffer solution (pH 6.8) as release media was determined with chromogenic reaction of vanillin- sulfuric acid. The release rates are 23.80%, 51.26% and 94.77% at release times 3, 6 and 12 h, respectively in phosphate buffer solution (pH 6.8) as release media. The controlled-release tablets of SQS-casein release SQS by slowness and constant in 12 h. The chemical bonds are formed among SQS, casein and guar gum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1650 (2012)
The Enhancement Effect of Potassium Additives on ICP Source Radiation
CHEN Jin-zhong, WEN Nuan, SUN Jiang, LI Xu, and YANG Bao-zhu
In order to improve the quality of inductively coupled plasma-atomic emission spectrum and reduce the detection limit of analysis, the influence of potassium additives into water samples on water samples’ spectral intensity and signal-to-background ratio was studied. The excitation temperature and electron density of pIn order to improve the quality of inductively coupled plasma-atomic emission spectrum and reduce the detection limit of analysis, the influence of potassium additives into water samples on water samples’ spectral intensity and signal-to-background ratio was studied. The excitation temperature and electron density of plasma were measured through multi-line slope and the Stark broadening method. The results demonstrated that the plasma spectral intensity intensity increases to a various degree after adding potassium additives into the sample solution. When the content of the potassium is 1.0 g·L-1, the spectral lines intensity of element Al, Cr, Cu, Mn, Ni and Zn was increased by 8.62%, 32.29%, 108.45%, 6.06%, 64.98% and 54.99% respectively, the spectral signal-background ratio increased by about 7.90%, 30.95%, 104.60%, 5.21%, 66.00% and 52.82%, respectively. Under the conditions of the content of potassium is 1.0 g·L-1 in the sample, the plasma excitation temperature increased by about 239.69 K than that without additive, and the electron density increased by about 4.99×1011 cm-3. It is thus clear that potassium additives can improve the quality of inductively coupled plasma-atomic emission spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1654 (2012)
Quantitative Analysis of Ba and Sr in Soil Using Laser-Induced Breakdown Spectroscopy
CHEN Tian-bing, YAO Ming-yin, LIU Mu-hua*, LEI Ze-jian, PENG Qiu-mei, XU Yuan, and ZHANG Xu
Laser induced breakdown spectroscopy(LIBS) was applied to measure barium and strontium elements in soil. The emission spectrum was emitted as the plasma was cooling off, which was collected and analyzed by fiber spectrometer. Spectral lines of barium(BaII line at 455.41 nm) and strontium(SrI line at 460.73 nm) were sepLaser induced breakdown spectroscopy(LIBS) was applied to measure barium and strontium elements in soil. The emission spectrum was emitted as the plasma was cooling off, which was collected and analyzed by fiber spectrometer. Spectral lines of barium(BaII line at 455.41 nm) and strontium(SrI line at 460.73 nm) were separately used for the determining. In order to reduce the error, fitting of the spectra by using Lorenizian function was used, the datum was preprocessed and the net intensity value of the spectra was collected. A signal intensity in the proper range of the characteristic spectrum was chosen as the interior label. A calibration curve was drawn according to the ratio between the value of the analytical line and the interior scaling line . The correlation coefficient between the content and the intensity ratio of Ba and Sr were up to 0.990 0 and 0.990 6. The content of Ba and Sr was inversed by means of the intensity scaling method .As a result , the relative deviations between the content values and the standard values of Ba and Sr were 5.7% and 5.1% respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1658 (2012)
Study on Microwave Digestion of Coal for the Determination of Multi-Element by ICP-OES and ICP-MS
WANG Hui, SONG Qiang, YAO Qiang, CHEN Chang-he, and YU Fei-lu
Effects of temperature and four acids(HNO3, HNO3/H2O2, HNO3/HF and HNO3/HF+H3BO3)on the coal decomposition by microwave digestion and the multi-element analysis were studied. SARM20 was used as a coal standard reference material. The contents of 10 mineral elements(Al, Ca, Fe, Mg, K, Na, S, Si, Sr and Ti)in the coal SAEffects of temperature and four acids(HNO3, HNO3/H2O2, HNO3/HF and HNO3/HF+H3BO3)on the coal decomposition by microwave digestion and the multi-element analysis were studied. SARM20 was used as a coal standard reference material. The contents of 10 mineral elements(Al, Ca, Fe, Mg, K, Na, S, Si, Sr and Ti)in the coal SARM20 were determined by inductively coupled plasma-optical emission spectrometry(ICP-OES). And the contents of 20 heavy metals(Li, Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Zr, Sn, Cs, Ba, Ce, Eu and Pb)were determined by inductively coupled plasma-mass spectrometry(ICP-MS). The results showed that the coal was completely decomposed by microwave digestion with HNO3/HF+H3BO3 at 210 ℃. Good recoveries for all elements in the coal SARM20 were obtained by this two-step microwave digestion method. The recoveries of the 10 mineral elements were from 87.5% to 98.8%, and the recoveries of the 20 heavy metals were from 85% to 112.5%. All RSDs of tests were below 3%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1662 (2012)
Determination of Lithium and Strontium at High Concentration by ICP-AES
ZHAO Jing, LI Hai-jun, SUN Bai, and SONG Peng-sheng
The concentrations of lithium and strontium of highly concentrated lithium-strontium mixed solution were determined simultaneously by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). After considering total salinity, relation coefficient and intensity at different wavelengths of lithium and strontium The concentrations of lithium and strontium of highly concentrated lithium-strontium mixed solution were determined simultaneously by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). After considering total salinity, relation coefficient and intensity at different wavelengths of lithium and strontium respectively, the determination wavelength was chosen for lithium and strontium separately. Using the determined wavelength, the result varies in terms of acid effect, equipment operating parameters and total salinity in the mixed solution. When the total salinity was in the range of 0.20%～0.60%, the linear correlation coefficient of Li and Sr was better than 0.999 9. After optimizing the instrument parameters, the standard solutions relative errors were within +0.59%～-0.66%, and the samples recoveries were within 99.14%～100.4%. This method is reliable due to stability and good recurrence. It can be used to determine high concentration of lithium and strontium ions in the lithium-strontium mixed solution accurately and rapidly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1666 (2012)
The Chemical and Structural Analysis of Tibetan Medicine Zhuxi
LI Cen, Sang-lao, Leng-bencairang, XIA Zhen-jiang, DU Yu-zhi, and WEI Li-xin
Zhuxi is a mineral medicine widely used in traditional Tibetan medicine throughout history. However, the bioactive component in Zhuxi still remains unclear. In order to enunciate the material basis of its pharmacological activity, the present research has determined the chemical component and structure of Zhuxi. X-ray Zhuxi is a mineral medicine widely used in traditional Tibetan medicine throughout history. However, the bioactive component in Zhuxi still remains unclear. In order to enunciate the material basis of its pharmacological activity, the present research has determined the chemical component and structure of Zhuxi. X-ray fluorescence spectroscopy (XRF), inductively coupled plasma optical emission spectrometer (ICP-OES) and X-ray diffraction (XRD) were utilized to assay two samples of Zhuxi. XRF and ICP-OES analysis indicated that the main elements in Zhuxi are Fe, S and O, also containing some minor elements, such as Si, Na, Mg, Al, K, Ni, Ca, Ti and so on. XRD analysis suggested that the main crystal compound in Zhuxi is FeS2 (Cubic, Pa-3), also existing a few of Fe+3O(OH)(orthorhombic, Pbnm) and other some unknown compounds. These studies has highlighted the potential the element components and compound structures of Zhuxi, so it may be a good starting point for exploring the material basis of its pharmacological activity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1671 (2012)
Detection of Trace Elements in the Sediment of Lop Nur Samples by ICP-MS
HU Xin, AN Deng-di, DLINUR Mlik, LI Jiang, LIU Yu-xiang, JI Heng-ying, and ZHU Yan-lei
Twenty eight trace elements in the sediment of Lop Nur in different latitude and longitude were tested by ICP-MS. The results showed that the metal contents in the soil profile followed a growing trend from the surface to the bottom. And the essential element P for living body in each sample was very low, and was the lTwenty eight trace elements in the sediment of Lop Nur in different latitude and longitude were tested by ICP-MS. The results showed that the metal contents in the soil profile followed a growing trend from the surface to the bottom. And the essential element P for living body in each sample was very low, and was the lowest on the surface, while was matched in the other four layers. The results will help to understand the ecosystem evolution of Lop Nur drying up after the sediment deposition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1674 (2012)
Study on the Adsorption Behavior of Beads of Maleic Anhydride-co-Styrene to Pb(Ⅱ) by FAAS
Abderyim Sopahun, Shawket Abliz, and Ismayil Nurulla
The crosslinked polymer beads was synthesized by free emulsion polymerization using maleic anhydride and styrene. The chemical structure and morphology of the polymer beads were analyzed using FTIR and SEM. And the dynamic adsorption properties of beads for Pb(Ⅱ) was studied by atomic adsorption spectrometry(AAS). The The crosslinked polymer beads was synthesized by free emulsion polymerization using maleic anhydride and styrene. The chemical structure and morphology of the polymer beads were analyzed using FTIR and SEM. And the dynamic adsorption properties of beads for Pb(Ⅱ) was studied by atomic adsorption spectrometry(AAS). The relevant factors influencing adsorption and desorption were investigated. The results showed that in the solution at pH 5, when the sample flow rate was 1.0 mL·min-1, the adsorption rate of Pb(Ⅱ) reached more than 95%. Using 1 moL·L-1 nitrate acid as the best eluant the absorbates were desorbed at the flow rate of 0.5 mL·min-1, the recovery of Pb(Ⅱ) reached more than 99%. Under the optimum conditions, the adsorption capacity could be up to 26.5 mg·g-1, the detection limits(3σ11)were 2.1 μg·L-1 and relative standard deviation (RSD) was 2.5%. The method has been applied to the determination of trace lead in water samples with satisfactory results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1677 (2012)
Rapid Determination of Silicon Content in Black Liquor of Straw Fibrous Material
LI Hai-long, CHAI Xin-sheng, ZHAN Huai-yu, LIU Meng-ru, FU Shi-yu, and SUN Li-jin
The present paper reports a novel method for the determination of silicon content in straw fibrous material black liquor based on α-Si—Mo heteropoly acid spectrophotometry. The selected conditions were as follows: detection wavelength 360 nm, pH 4.0, and reaction time 10 min. It was found that the acidic soluble ligninThe present paper reports a novel method for the determination of silicon content in straw fibrous material black liquor based on α-Si—Mo heteropoly acid spectrophotometry. The selected conditions were as follows: detection wavelength 360 nm, pH 4.0, and reaction time 10 min. It was found that the acidic soluble lignin in the sample liquor was the major interference species in the silicon content determination. The interference of acidic soluble lignin can be eliminated by hydrogen peroxide-nitric acid digestion method. The present method is not only simple, rapid, stable and less interferential, but also of good measurement precision and accuracy, with the relative standard deviations of 0.9%, and recoveries of 99.0%～102%. It is suitable for use in high silicon content of black liquor routine rapid analyses..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1681 (2012)
Distribution of Lignin in Chinese Fir Branches determined by Ultraviolet Microspectrometer
WANG Yu-rong, XING Xin-ting, REN Hai-qing, YU Yan, and FEI Ben-hua
Distribution of lignin in the cell walls of Chinese fir branches emerged in the spring season were first studied by using ultraviolet microscope based on their cell microstructure observation and lignin qualitative measurement by the lightmicroscope and confocal laser scanning microscope. The results showed that the coDistribution of lignin in the cell walls of Chinese fir branches emerged in the spring season were first studied by using ultraviolet microscope based on their cell microstructure observation and lignin qualitative measurement by the lightmicroscope and confocal laser scanning microscope. The results showed that the contents of lignin are inhomogeneously distributed in different micro-areas of the cell walls. The order of lignin concentrations is the cell corner>the middle lamellar>the secondary with the absorbance values of ultraviolet wave of 0.489, 0.307 and 0.278, respectively. The result of quantitative analysis consists with that of qualitative analysis. A new measurement method was proposed to study the distribution of lignin content in wood cell walls in CFhina..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1685 (2012)
A New Automated Method to Identify Emission Line Star from Massive Spectra
PAN Jing-chang, ZHANG Cai-ming, WEI Peng, LUO A-li, and ZHAO Yong-heng
Stellar spectra are characterized by obvious absorption lines or absorption bands, while those with emission lines are usually special stars such as cataclysmic variable stars (CVs), HerbigAe/Be etc. The further study of this kind of spectra is meaningful. The present paper proposed a new method to identify emission liStellar spectra are characterized by obvious absorption lines or absorption bands, while those with emission lines are usually special stars such as cataclysmic variable stars (CVs), HerbigAe/Be etc. The further study of this kind of spectra is meaningful. The present paper proposed a new method to identify emission line stars (ELS) spectra automatically. After the continuum normalization is done for the original spectral flux, line detection is made by comparing the normalized flux with the mean and standard deviation of the flux in its neighbor region. The results of the experiment on massive spectra from SDSS DR8 indicate that the method can identify ELS spectra completely and accurately. Since no complex transformation and computation are involved in this method, the identifying process is fast and it is ideal for the ELS detection in large sky survey projects like LAMOST and SDSS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1689 (2012)
Study on Spectrum Inversion of Spatially Modulated Fourier Transform Spectrometer
Lv Jin-guang, LIANG Jing-qiu, and LIANG Zhong-zhu1
The sampling mode of static Fourier transform spectrometer is spatial domain sampling. The interferogram function is sampled by two orthogonal stepped mirrors and the interference irradiance is received by the detector. The interferogram image is a planar spatial array which consists of M×M interferogram units. AfThe sampling mode of static Fourier transform spectrometer is spatial domain sampling. The interferogram function is sampled by two orthogonal stepped mirrors and the interference irradiance is received by the detector. The interferogram image is a planar spatial array which consists of M×M interferogram units. After image segmentation, the interferogram image is divided into M×M interferogram units according to comparability criterion. By means of addressing location, the sampled interferogram sequence which matches up to the discrete optical path difference sequence could be gained. Using over-zero sampling technique, the big single side interferogram sequence and the small double side interferogram sequence are apodizated by different window functions. For the sake of correcting phase error, the frequency-domain spectrum correction and space-domain interferogram correction are researched and improved. The simulation result shows that the two methods can both gain the perfect spectrum line shape, and the effect of space-domain interferogram correction is better than others with the spectrum standard deviation only 0.012 088..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1694 (2012)
Application of ADV212 to the Large Field of View Multi-Spectral TDICCD Space Camera
LI Jin, JIN Long-xu, LI Guo-ning, ZHANG Ke, and WANG Wen-hua
In order to resolve the difficult to hardware implementation of the whole vector quantization-based, predictive coding-based and transform coding-based compression scheme caused by the large volume of data, small spectral redundancy and line frequency variability etc. in multi-spectral space camera, an image compressioIn order to resolve the difficult to hardware implementation of the whole vector quantization-based, predictive coding-based and transform coding-based compression scheme caused by the large volume of data, small spectral redundancy and line frequency variability etc. in multi-spectral space camera, an image compression scheme based on ADV212 was proposed in space camera. Firstly, custom-specific mode was presented based on the working principle of adv212 and CCD image properties. In the Custom-specific mode, an ADV212 is able to compress 8 channel CCD data by proposed image frame and interrupt processing strategy using pipelining. Then, this paper analyses the two parameters which affect the quality of image compression. A (10, 5) setting the quantization step method was proposed. This method makes the rate control error reduces 16.385%. Finally, the verification experiments to ADV212 compression system using ground test equipment were carried out. The experiments results showed that compression system can be fast and stable work. All PSNR were more than 30dB in the compression ratio of 2∶1 to 32∶1. Compared with traditional approaches, the proposed method could improve the average PSNR by 2.49 dB in the lossy compression mode when the compression ratio is 1bpp. They effectively solve the difficult of hardware implementation of the whole wavelet-based compression scheme..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1700 (2012)
A Wide-Field Push-Broom Hyperspectral Imager Based on Curved Prism
NIE Yun-feng, XIANGLI Bin, ZHOU Jin-song, and HUANG Min
A wide-field pushbroom hyperspectral imager covering short-wavelength infrared range is presented, which can be carried by space borne or airborne platform for remote sensing, acquiring hyperspectral data cube, and analyzing substance compositions and physicochemical properties. Curved prism which simultaneously possesA wide-field pushbroom hyperspectral imager covering short-wavelength infrared range is presented, which can be carried by space borne or airborne platform for remote sensing, acquiring hyperspectral data cube, and analyzing substance compositions and physicochemical properties. Curved prism which simultaneously possesses the functions of dispersion and imaging is used as the prismatic element, and the combination with Offner relay configuration substantially simplifies the design of spectrometer. Compared to conventional dispersive spectral imagers, this design is compact, light-weighted, and small-sized, and can efficiently correct unavoidable spectral line curve (smile) and spectral band (keystone or frown) by prismatic dispersion. Compared to grating spectral imagers of the same configuration, the energy utilization efficiency of this design is much higher. The paraxial aberration theory and imaging characteristics of Offner relay configuration is briefly described. The optical layout and image evaluations, including spatial and spectral dimensions, are illustrated respectively, according to Monte Carlo ray-tracing results of seven principal wavelengths..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1708 (2012)
An Interferometer Design for Fourier Transform Infrared Spectrometer
SHI Lei, LIU Jia, ZHENG Xin-wen, ZENG Li-bo, and WU Qiong-shui
A novel interferometer system based on the combinations of cube-corner reflectors and fixed plane mirrors was designed to improve the quality of spectra. It consists of a pair of cube corner reflectors, two fixed perpendicular plane mirrors and one beam splitter. By analyzing the modulation depth and phase error, the tA novel interferometer system based on the combinations of cube-corner reflectors and fixed plane mirrors was designed to improve the quality of spectra. It consists of a pair of cube corner reflectors, two fixed perpendicular plane mirrors and one beam splitter. By analyzing the modulation depth and phase error, the tilt and shearing of the cube corner reflectors, the deviation angle of cube corner reflector, the tilt of fixed plane mirrors and the deviation angle of two fixed plane mirrors were analyzed. It was proved that the tilt and shearing of the cube corner reflectors, and the deviation angle of two fixed plane mirrors, have no effects on the modulation depth and phase error of this new interferometer system, and the effect from the vibration, temperature fluctuations and other external environmental factors also can be effectively reduced, which can significantly improve the spectral resolution and quality. Through some experiments, it was found that the instrument has a simple structure, good sealing, high resolution, strong stability and other advantages.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1712 (2012)
Design of Concave Grating for Ultraviolet-Spectrum
LUO Biao, WEN Zhi-yu, WEN Zhong-quan, and ZENG Tian-ling
Ultraviolet-spectrum technology is a kind of low signal and multianalysis technology. For taking full advantage of spectral information and reducing the volume of spectrometer, we used high efficiency spectroscopy structure based on concave grating. Based on concave grating theory and optic design software ZEMAX, a flaUltraviolet-spectrum technology is a kind of low signal and multianalysis technology. For taking full advantage of spectral information and reducing the volume of spectrometer, we used high efficiency spectroscopy structure based on concave grating. Based on concave grating theory and optic design software ZEMAX, a flat field concave grating for ultraviolet spectrophotometer was designed from primary structure, which relied on global optimization of the software. The contradiction between wide spectrum bound and limited spectrum extension was resolved, aberrations were reduced successfully, spectrum information was utilized fully, and the optic structure of spectrometer was highly efficient. For better preference of this spectrophotometer, after get the structure parameter, combine grating fabrication condition with practice working condition, grating diffractive theory, holographic optics theory and software PCGrate was used for diffraction efficiency design and improve. A paradigm of flat field concave grating is given, it works between 190 nm to 410 nm, the diameter of the concave grating is 20 mm, and F/# is 0.21. The design result was analyzed and evaluated. It was showed that if the slit source, whose width is 50μm, is used to reconstruction, the theoretic resolution capacity is better than 3 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1717 (2012)
A Two-Dimensional Double Dispersed Hadamard Transform Spectrometer
LIU Jia, SHI Lei, LI Kai, ZHENG Xin-wen, ZENG Li-bo, and WU Qiong-shui
A kind of two-dimensional hadamard transform spectrometer was developed. A grating was used for chromatic dispersion of orders and a prism was used for spectral dispersion. Quite different from traditional CCD detection method, a digital micromirror device (DMD) was applied for optical modulation, and a simple point deA kind of two-dimensional hadamard transform spectrometer was developed. A grating was used for chromatic dispersion of orders and a prism was used for spectral dispersion. Quite different from traditional CCD detection method, a digital micromirror device (DMD) was applied for optical modulation, and a simple point detector was used as the sensor. Compared with traditional two-dimensional spectrometer, it has the advantage of high resolution and signal-noise-ratio, which was proved by theoretical calculation and computer simulation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1722 (2012)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 1 (2012)
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