Journals >Spectroscopy and Spectral Analysis
Contents
2011
Volume: 31 Issue 6
63 Article(s)
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Research Article
GaN-Based White-Light-Emitting Diodes with Low Color Temperature and High Color Rendering Index
WANG Feng, HUANG Xiao-hui, WANG Huai-bing, LIU Jian-ping, FAN Ya-ming, ZHU Yun-zhi, and JIN Zheng
The luminescence properties of high color rendering white LED depending on the proportions of mixed phosphor powders were investigated by adopting green and red phosphors stimulated by a 440 nm InGaN/GaN based blue LED. The results show that when the proportion of A/B type silica gels and green/red phosphor powders is The luminescence properties of high color rendering white LED depending on the proportions of mixed phosphor powders were investigated by adopting green and red phosphors stimulated by a 440 nm InGaN/GaN based blue LED. The results show that when the proportion of A/B type silica gels and green/red phosphor powders is 0.5∶0.5∶0.2∶0.03, two luminance bands are stimulated and their wavelength peaks are 535 and 643 nm, respectively. The minimum color temperature can reach 3 251 K, while the color rendering is as high as 88.8. Compared with the traditional white LED fabricated by yellow YAG-phosphors-coated high efficiency 460 nm blue LED, the color temperature is lower and the color rendering index can be increased by almost 26%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1446 (2011)
The Effect of Temperature on the PL Spectra of High Power LED
DING Tian-ping, GUO Wei-ling*, CUI Bi-feng, YIN Fei, CUI De-sheng, and YAN Wei-wei
Two kinds of 1 W white high power light emitting diode (LED) were made by packaging blue chips from Taiwan and US. The chips were coated by the same phosphor and transparent silica gel. Optical properties of the two kinds of LEDs were investigated in the temperature range of 15～75 ℃ and at the current of 350 mA. The reTwo kinds of 1 W white high power light emitting diode (LED) were made by packaging blue chips from Taiwan and US. The chips were coated by the same phosphor and transparent silica gel. Optical properties of the two kinds of LEDs were investigated in the temperature range of 15～75 ℃ and at the current of 350 mA. The results show that temperature badly affects the optical parameters such as peak wavelength, radiant flux, color temperature and so on. After analyzing the PL spectrum, the relationship between temperature and LED performance was found. The reasons for optical parameters vs. temperature were theoretically analyzed. Some suggestions were given to reduce the influence of temperature on power LED..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1450 (2011)
Effect of Mixed Interface on the Performance of Solution-Processed Phosphorescent OLEDs
SONG Dan-dan, ZHAO Su-ling, XU Zheng, ZHANG Fu-jun, LU Li-fang, ZHANG Yan-fei, KONG Chao, and YAN Guang
In the present work, in order to improve electron injection and transport at the interface of the hole blocking layer (HBL) and the electron transport layer (ETL) in the hole-domain solution processed phosphorescent organic light emitting devices (PhOLEDs), the mixed interface layer (MIL) was fabricated by partially coIn the present work, in order to improve electron injection and transport at the interface of the hole blocking layer (HBL) and the electron transport layer (ETL) in the hole-domain solution processed phosphorescent organic light emitting devices (PhOLEDs), the mixed interface layer (MIL) was fabricated by partially co-doping hole blocking material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and electron transport material tris(8-quinolinolato) aluminum (Alq3) between HBL/ETL. The MIL thickness was kept at 10nm, while the doping ratio of these two materials varied. Under a given electric field, the devices with the MIL at any mixed ratios all show much higher luminance and current density than those with a typical interface. For example, the luminance power and current density at 10 V for a typical device are 1.03 μW and 5.13 mA·cm-2, while in case of mixed interface are 3.64 μW and 18.1 mA·cm-2, respectively. From data results and theoretical analysis, the possible derivation of these improvements is considered to be the reduced electron accumulation at the interface resulting from the reduced electron injection energy barrier and lowered transport mobility by BCP material, which leads to an increase in electron amount in the emission layer and therefore the higher luminance and current density..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1454 (2011)
Ultrasonic Nebulizer Assisted LIBS for Detection of Trace Metal Elements Dissolved in Water
ZHONG Shi-lei, LU Yuan, CHENG Kai, XIU Jun-shan, and ZHENG Rong-er
Because of the complex factors in bulk water, the effect of LIBS on the analysis of liquid sample is limited in liquid sample. Under this circumstances, a new method of LIBS assisted by ultrasonic nebulizing technology has been introduced. According to this method, the liquid sample is transformed into dense droplets bBecause of the complex factors in bulk water, the effect of LIBS on the analysis of liquid sample is limited in liquid sample. Under this circumstances, a new method of LIBS assisted by ultrasonic nebulizing technology has been introduced. According to this method, the liquid sample is transformed into dense droplets by ultrasonic nebulizing technology, and these dense droplets are subjected to the analysis of LIBS later. Based on this thought, a detection experimental system was established, composing of ultrasonic system, 1 064 nm ND:YAG laser, and ICCD system. A series of experiments and analysis were carried out to detect the magnesium element dissolved in pure water using the detection experimental system mentioned above. The results showed that even with a very low laser pulse energy (30 mJ), the signals of LIBS still have a long lifetime and a high signal to background ratio. The limit of detection for magnesium element could reach as low as 0.242 ppm. At the same time, the electron density of plasma was calculated utilizing the Hα line to give the evolution features of plasma induced by this new method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1458 (2011)
Controlled Syntheses and Photoluminescence Characterization of Monoclinic Cerium Orthophosphate with Nanostructure
BAO Jin-rong, ZHU Xiao-wei, WEI Li-si, PENG Jun-wen, and LI Wen-xian
The nanostructured CePO4 with monoclinic phase was controllably synthesized through a low temperature hydrothermal route by varying the reactant PO3-4/Ce3+ molar ratio. The structures, morphologies, sizes and luminescence properties of the products were studied by XRD, FE-SEM, DSC-TG and photoluminescence spectra. WithThe nanostructured CePO4 with monoclinic phase was controllably synthesized through a low temperature hydrothermal route by varying the reactant PO3-4/Ce3+ molar ratio. The structures, morphologies, sizes and luminescence properties of the products were studied by XRD, FE-SEM, DSC-TG and photoluminescence spectra. With the PO3-4/Ce3+ molar ratios increased, the synthesis temperature of as-synthesized monoclinic CePO4 was decreased, and the morphologies underwent the evolution from the rod-like nano-structures to the flower-like nanoclusters. When the PO3-4/Ce3+ molar ratio was lower, CePO4 nanorods were obtained, while the PO3-4/Ce3+ molar ratio was higher, the monoclinic CePO4 flower-like nanoclusters were crystallized. The photoluminescence spectrum showed that the CePO4 nanorods exhibit better photoluminescent property than the CePO4 flower-like nanoclusters. With the cycling use of phosphoric acid, the low-cost preparation of CePO4 could be achieved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1463 (2011)
Study on Self-Propagating Synthesis of the Doped SrAl2O4 Rare Earth Long Afterglow Phosphors
LI Yuan, ZHAO Yong-liang, LIU Yong-gang, WEI Xiao-yan, and REN Yue
Twenty one doped SrAl2O4 long after-glowed phosphors with 4 series were synthesized by self-propagating high-temperature synthesis method (SHS) with urea-nitrate solution which served as media at 600 ℃. They are SrAl2O4∶Eu2+0.012 5, RE3+0.012 5(RE3+=Ce3+, Pr3+, Nd3+, Tb3+, Dy3+), SrAl2O4∶Eu2+0.012 5, M0.012 5(M=Li+, BeTwenty one doped SrAl2O4 long after-glowed phosphors with 4 series were synthesized by self-propagating high-temperature synthesis method (SHS) with urea-nitrate solution which served as media at 600 ℃. They are SrAl2O4∶Eu2+0.012 5, RE3+0.012 5(RE3+=Ce3+, Pr3+, Nd3+, Tb3+, Dy3+), SrAl2O4∶Eu2+0.012 5, M0.012 5(M=Li+, Be2+, Cd2+, Mn2+, Cu2+, Ag+, Zn2+, Pb2+), SrAl2O4∶Eu2+0.012 5, Dy3+0.012 5, M0.012 5(M=Mn2+, Cu2+, Ag+, Zn2+), and SrAl2O4∶Eu2+0.012 5, Dy3+0.012 5, RE3+0.012 5(RE3+=Ce3+, Pr3+, Nd3+, Tb3+), of which luminescence and after-glowing features were tested. The morphology of all these samples presents a state of porosity and laxity. The samples show an intense emission peak at 514 nm and broad peaks of the excitation spectra at 290～360 nm, Tb3+ and Dy3+ had most effects on luminance and after-glowed time respectively. The SrAl2O4∶Eu2+0.012 5, Dy3+0.012 5 had good luminance and proper after-glowed time as well..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1467 (2011)
Flow-Injection Chemiluminescence Determination of Trace Copper On-Line Separation and Enrichment by Ion Imprinted Polymer
LI Hui-zhi, PEI Mei-shan, ZHANG Jin, and WEI Qin
In the present study, Cu(Ⅱ)-imprinted polymer was prepared and used as an effective method for separation and enrichment of Cu(Ⅱ) ion in samples. An on-line preconcentration and extraction flow-injection system using solid phase extraction (SPE) column packed with prepared ion imprinted polymer (IIP) was set up. The coIn the present study, Cu(Ⅱ)-imprinted polymer was prepared and used as an effective method for separation and enrichment of Cu(Ⅱ) ion in samples. An on-line preconcentration and extraction flow-injection system using solid phase extraction (SPE) column packed with prepared ion imprinted polymer (IIP) was set up. The column was eluted with a mixture of ethanol and H2SO4 after preconcentration. A sensitive and simple chemiluminescence(CL) method using flow-injection has been developed for the determination of copper. The method is based on the fact that traces of Cu(Ⅱ) exert a catalytic action on the oxidation between morin by KMnO4 solution. After optimizing the different experimental parameters, a calibration graph was obtained over the concentration range of 0 to 10 μg·mL-1 for Cu(Ⅱ) and r=0.996 8. The detection limit is 0.001 2 μg·mL-1. The recoveries are between 95% and 105% and the standard relative deviations( RSD) are less than 3% at 4.0 μg·mL-1 (n=9) level was obtained. The new chemiluminescence determination for copper has been established. The method can be satisfactorily applied to the determination of copper in sample..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1472 (2011)
Utilization of Thermal Infrared Image for Inversion of Winter Wheat Yield and Biomass
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The present paper utilizes thermal infrared image for inversion of winter wheat yield and biomass with different technology of irrigation (drip irrigation, sprinkler irrigation, flood irrigation). It is the first time that thermal infrared image is used for predicting the winter wheat yield and biomass. The temperatureThe present paper utilizes thermal infrared image for inversion of winter wheat yield and biomass with different technology of irrigation (drip irrigation, sprinkler irrigation, flood irrigation). It is the first time that thermal infrared image is used for predicting the winter wheat yield and biomass. The temperature of crop and background was measured by thermal infrared image. It is necessary to get the crop background separation index (CBSIL, CBSIH), which can be used for distinguishing the crop value from the image. CBSIL and CBSIH (the temperature when the leaves are wet adequately; the temperature when the stomata of leaf is closed completely) are the threshold values. The temperature of crop ranged from CBSIL to CBSIH. Then the ICWSI was calculated based on relevant theoretical method. The value of stomata leaf has strong negative correlation with ICWSI proving the reliable value of ICWSI. In order to construct the high accuracy simulation model, the samples were divided into two parts. One was used for constructing the simulation model, the other for checking the accuracy of the model. Such result of the model was concluded as: (1) As for the simulation model of soil moisture, the correlation coefficient (R2) is larger than 0.887 6, the average of relative error (Er) ranges from 13.33% to 16.88%; (2) As for the simulation model of winter wheat yield, drip irrigation (0.887 6, 16.89%, -0.12), sprinkler irrigation (0.970 0, 14.85%, -0.12), flood irrigation (0.969 0, 18.87%, -0.18), with the values of R2, Er and CRM listed in the parentheses followed by the individual term. (3) As for winter wheat biomass, drip irrigation (0.980 0, 13.70%, -0.13), sprinkler irrigation (0.95, 13.15%, -0.14), flood irrigation (0.970 0, 14.48%, -0.13), and the values in the parentheses are demonstrated the same as above. Both the CRM and Er are shown to be very low values, which points to the accuracy and reliability of the model investigated. The accuracy of model is high and reliable. The results indicated that thermal infrared image can be used potentially for inversion of winter wheat yield and biomass..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1476 (2011)
Research on Continuum Power Regression in Noninvasive Measurement of Human Blood Glucose
LI Qing-bo, LIU Jie-qiang, and ZHANG Guang-jun
Accurate measurement of human blood glucose concentration is very significant for the treatment of diabetes. In the present paper, the method of continuum power regression can improve the predictive accuracy of noninvasive measurement of human blood glucose concentration with near infrared spectroscopy. This method is Accurate measurement of human blood glucose concentration is very significant for the treatment of diabetes. In the present paper, the method of continuum power regression can improve the predictive accuracy of noninvasive measurement of human blood glucose concentration with near infrared spectroscopy. This method is the expansion of the traditional method of partial least squares (PLS). It can achieve simpleness, and can significantly improve predictive accuracy when the power coefficient is fit. Using the method, quantitative analysis models of four ingredient experiment and noninvasive experiment of body were established, and these models can be used to predict the predictive samples. Experimental results show that compared with the PLS, the quantitative analysis models of this method not only can improve predictive accuracy, but also can set different power coefficient for different individuals to achieve the best results of models. According to different individuals, the power coefficient can be selected flexibly, which is of great value to the research on noninvasive measurement of human blood glucose concentration with near infrared spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1481 (2011)
Determination of Chemical Oxygen Demand in Water Using Near Infrared Transmission and UV Absorbance Method
WU Guo-qing, BI Wei-hong, LV Jia-ming, and FU Guang-wei
Chemical oxygen demand (COD) is a synthetical indicator which represents the degree of organic pollution in water. The near-infrared (NIR) transmission and the UV absorbance method based on photoelectric detection technology and spectroscopy analysis have some advantages such as high precision, speed, non-contact, no sChemical oxygen demand (COD) is a synthetical indicator which represents the degree of organic pollution in water. The near-infrared (NIR) transmission and the UV absorbance method based on photoelectric detection technology and spectroscopy analysis have some advantages such as high precision, speed, non-contact, no secondary pollution etc compared to conventional wet chemical method. The NIR transmission spectra and UV absorbance spectra of standard solution configured with phthalate hydrogen potassium were collected respectively by MPA FTIR spectrometer (Bruker Optics Inc.) made in Germany and AvaSpec-2048-2 UV spectrometer (Avantes Inc.) made in Netherlands. After different pretreatment to the spectra, COD quantitative analysis model was established using partial least squares regression (PLS) and linear regression. The statistical analysis of COD quantitative model was implemented, and the result showed that UV absorbance method had a higher relevance but lower forecast accuracy and precision than NIR transmission method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1486 (2011)
Assessment of the Effects of Pressure on Sacrum Tissue Oxygenation Using Near Infrared Spectroscopy
LI Zeng-yong, WANG Yan, XIN Qing, LU Chang-hou, LI Jian-ping, and ZHANG Liang-liang
The objective of the present study is to assess the effect of pressure on blood oxygenation in the sacrum tissue (high-risk area for pressure ulcer) based on near infrared spectroscopy (NIRS) signals. NIRS was used to detect the change in the value of blood oxygenation. Thirty subjects were recruited, of which ten wereThe objective of the present study is to assess the effect of pressure on blood oxygenation in the sacrum tissue (high-risk area for pressure ulcer) based on near infrared spectroscopy (NIRS) signals. NIRS was used to detect the change in the value of blood oxygenation. Thirty subjects were recruited, of which ten were elders (average age, 73.4 y ), ten were persons with spinal cord injury (average age, 32 y) and ten were healthy persons (average age, 25 y). In resting conditions, the blood oxygenation in sacrum tissue of the 30 subjects was monitored for 20 minutes prior to and after the three-minute loading period. The results show that the first three oxygenation parameters in the elderly and persons with spinal cord injury (SCI) changed significantly during the loading period (p<0.01) and took longer time to return to the normal level than the health persons. TOI in the three groups decreased with the pressure and returned after pressure release. These findings indicated that pressure had significant effect on blood oxygenation and the oxygenation parameters are good indicators of evaluation of pressure sore risk..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1490 (2011)
Comparative Study on FTIR Spectra of Garlic from Different Geographical Populations
GUAN Ming, LI Xiao-jing, GUO Yong, LU Hai-bo, DU Wei-jun, and CHEN Jian
In the present paper, 25 garlic samples from different geographical populations were studied. FTIR spectra for each sample were obtained by using Fourier transform infrared spectrometer, and the similarity of garlic samples from different geographical populations was compared through “quick comparison” function in softIn the present paper, 25 garlic samples from different geographical populations were studied. FTIR spectra for each sample were obtained by using Fourier transform infrared spectrometer, and the similarity of garlic samples from different geographical populations was compared through “quick comparison” function in software of the spectrometer. The results showed that there are differences among FTIR spectra of garlic samples from different geographical populations.The quick comparison showed that the similarity is from 76.3% to 99.8% and the diversity of differentiation is more obvious. To some extent, the results reflected the effects of populations environment on physical and chemical properties of garlic. The study provided a simple, rapid, non-destructive and new methods for identification and evaluation of garlic germplasm resources..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1494 (2011)
Study on Different Ploidy Siraitia Grosvenorii and Their Genetic Relationship by FTIR
YAN Hai-feng, HUANG Xi-yang, KONG De-xin, LAN Jin-yan, JIANG Shui-yuan, LI Feng, and LI Zhi-gang
Siraitia grosvenorii was an important Chinese traditional medicine. The spectra of leaf of diploid, triploid and tetraploid Siraitia grosvenorii were determined by Fourier transform infrared spectroscopy (FTIR) with OMNI sampler directly, fast and accurately. And based on the indices of wave number-absorbance from diffSiraitia grosvenorii was an important Chinese traditional medicine. The spectra of leaf of diploid, triploid and tetraploid Siraitia grosvenorii were determined by Fourier transform infrared spectroscopy (FTIR) with OMNI sampler directly, fast and accurately. And based on the indices of wave number-absorbance from different bands and through comparison of differences of these infrared spectra the ploidy difference and genetic relationship of Siraitia grosvenorii were studied by the methods of principal component analysis (PCA) and cluster analysis. The results showed that for the ploidy, the position relationship of PCA three-dimensional-plot and the distance coefficient of clustering analysis plot between diploid and tetraploid were most remarkbly different, and the triploid was basically between diploid and tetraploid, so the ploidy was more different, the position relationship of PCA and the distance coefficient of clustering analysis were further, and the law was: 2×<3×<4×. At the same time, the genetic relationship was further with each other while the position relationship of PCA and distance coefficient of clustering analysis was further too. And the genetic relationship of triploid was affected by the different male parent while their female parent was the same one. Therefore, using FTIR based on PCA and cluster analysis we could reveal the difference of ploidy and the genetic relationship between Siraitia grosvenorii to a certain extent. FTIR could be used for excellently polyploidy species breeding of Siraitia grosvenorii..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1498 (2011)
Study on Rapid Determination and Analysis of Rocket Kerosene by Near Infrared Spectrum and Chemometrics
XIA Ben-li, CONG Ji-xin, LI Xia, and WANG Xuan-jun
The rocket kerosene quality properties such as density, distillation range, viscosity and iodine value were successfully measured based on their near-infrared spectrum (NIRS) and chemometrics. In the present paper, more than 70 rocket kerosene samples were determined by near infrared spectrum, the models were built usiThe rocket kerosene quality properties such as density, distillation range, viscosity and iodine value were successfully measured based on their near-infrared spectrum (NIRS) and chemometrics. In the present paper, more than 70 rocket kerosene samples were determined by near infrared spectrum, the models were built using the partial least squares method within the appropriate wavelength range. The correlation coefficients (R2) of every rocket kerosene’s quality properties ranged from 0.862 to 0.999. Ten unknown samples were determined with the model, and the result showed that the prediction accuracy of near infrared spectrum method accords with standard analysis requirements. The new method is well suitable for replacing the traditional standard method to rapidly determine the properties of the rocket kerosene..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1502 (2011)
Early Detection of Corynespora Spot on Cucumber Leaves Based on FTIR Spectroscopy
CHAI A-li, LI Bao-ju, SHI Yan-xia, and XIE Xue-wen
Fourier transform infrared spectroscopy(FTIR)technique was applied in the early detection of corynespora spot on cucumber leaves while the symptom had not appeared. The cucumber leaves were inoculated with Corynespora cassiicola. By observing the changes in the FTIR spectra of infected cucumber leaves at various times Fourier transform infrared spectroscopy(FTIR)technique was applied in the early detection of corynespora spot on cucumber leaves while the symptom had not appeared. The cucumber leaves were inoculated with Corynespora cassiicola. By observing the changes in the FTIR spectra of infected cucumber leaves at various times of post-infection, three sensitive bands, 1 735, 1 545 and 1 240 cm-1 were selected for the identification of cucumber corynespora leaf spot. According to the peak areas at these sensitive bands, cucumber leaf samples infected with C. cassiicola and control uninfected leaf samples could be classified correctly. Results clearly demonstrated that the FTIR technology is an available one for the early detection of corynespora spot on cucumber leaves while the symptom has not appeared and it provides a new method for the early detection of corynespora spot..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1506 (2011)
Study on Estimation of Fall Dormancy in Alfalfa by Near Infrared Reflectance Spectroscopy and Support Vector Machine Model
WANG Hong-liu, YUE Zheng-wen, and LU Xin-shi
The present study proposes a new approach to producing accurate estimates of fall dormancy (FD) in alfalfa in a rapid manner. Using near infrared spectroscopy, the approach produces results fast without causing damage to samples. Near infrared reflectance spectroscopy was applied to measuring the spectra of samples. ThThe present study proposes a new approach to producing accurate estimates of fall dormancy (FD) in alfalfa in a rapid manner. Using near infrared spectroscopy, the approach produces results fast without causing damage to samples. Near infrared reflectance spectroscopy was applied to measuring the spectra of samples. Then principal component analysis (PCA) was conducted on the measurements. The top ten principal components were selected based on their cumulative contribution rates to build a support vector machine (SVM) model. Detailed analysis and discussions were conducted over their parameter and kernel classifications. The experiment found that when c=0.339 2 and g=32, the accuracy of the predictions of the test set can reach 98.182%. Therefore the approach can estimate the FD in alfalfa in a rapid and accurate manner. Moreover, it was compared with other approaches such as principal component regression, partial least squares regression, BP neural networks, and LVQ neural networks. The comparisons have shown that the PCA-SVM model can effectively address the small-sample-size problem and avoid local minimum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1510 (2011)
Gaussian Process Regression and Its Application in Near-Infrared Spectroscopy Analysis
FENG Ai-ming, FANG Li-min, and LIN Min
Gaussian process (GP) is applied in the present paper as a chemometric method to explore the complicated relationship between the near infrared (NIR) spectra and ingredients. After the outliers were detected by Monte Carlo cross validation (MCCV) method and removed from dataset, different preprocessing methods, such asGaussian process (GP) is applied in the present paper as a chemometric method to explore the complicated relationship between the near infrared (NIR) spectra and ingredients. After the outliers were detected by Monte Carlo cross validation (MCCV) method and removed from dataset, different preprocessing methods, such as multiplicative scatter correction (MSC), smoothing and derivate, were tried for the best performance of the models. Furthermore, uninformative variable elimination (UVE) was introduced as a variable selection technique and the characteristic wavelengths obtained were further employed as input for modeling. A public dataset with 80 NIR spectra of corn was introduced as an example for evaluating the new algorithm. The optimal models for oil, starch and protein were obtained by the GP regression method. The performance of the final models were evaluated according to the root mean square error of calibration (RMSEC), root mean square error of cross-validation (RMSECV), root mean square error of prediction (RMSEP) and correlation coefficient (r). The models give good calibration ability with r values above 0.99 and the prediction ability is also satisfactory with r values higher than 0.96. The overall results demonstrate that GP algorithm is an effective chemometric method and is promising for the NIR analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1514 (2011)
Preparation of EVOH Film and Infrared Spectroscopic Study of Its Heat Preservation Property
CUI Hai-long, WANG Zhao-hui, JIAO Hong-wen, LU Shi-xiang, and XU Wen-guo
EVOH, PE and EVA films were prepared by extrusive blowing techniques, the optic capability, transmittance, haze, infrared anti-transmittance and heat preservation of the films were studied by IR spectroscopy and optic block. The result indicated that the haze degree of the EVOH film decreased about 10% and 5% compared EVOH, PE and EVA films were prepared by extrusive blowing techniques, the optic capability, transmittance, haze, infrared anti-transmittance and heat preservation of the films were studied by IR spectroscopy and optic block. The result indicated that the haze degree of the EVOH film decreased about 10% and 5% compared to PE film and EVA film respectively, EVOH film’s transmission of IR is much less than other films in the 2.5～25 μm wavelength range, it is just 9.03% in 7～14 μm wavelength range, and about 27% less than EVA film, while much less than PE film. It was found that EVOH film has much better capability of infrared anti-transmittance and point-blank light transmission than other two kinds of films. It was good for calefaction and heat preservation of greenhouse..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1518 (2011)
Fast Determination of Contents of Nutrients and Stone Powder in Compound Fertilizer Using Near Infrared Diffuse Reflectance Spectroscopy
GUO Zheng, YUAN Hong-fu, ZHANG Xian, SONG Chun-feng, LI Xiao-yu, and XIE Jin-chun
In the present paper, a new approach to fast determination of contents of nutrients, including total nitrogen content(N), P2O5 content(P) and K2O content(K), and of stone powder content in compound fertilizer composed of urea, ammonium dihydrogen phosphate, potassium chloride and stone powder was proposed using near inIn the present paper, a new approach to fast determination of contents of nutrients, including total nitrogen content(N), P2O5 content(P) and K2O content(K), and of stone powder content in compound fertilizer composed of urea, ammonium dihydrogen phosphate, potassium chloride and stone powder was proposed using near infrared diffuse reflectance spectroscopy. PLS models of N, P and stone powder content were built with the SEP values of 0.8, 0.8 and 1.4 respectively. The information on which stone powder content model was built is the spectrum of crystal water existing in stone powder. K content was calculated using other ingredientcontents by normalization principle with a SEP value of 1.5. Although the SEP values are a little larger than the reproducibility errors of the GB/T methods which are conventional methods, the new method can be accepted by situ quality control in the production process of compound fertilizer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1521 (2011)
In situ Raman Spectroscopic Observation of Micro-Processes of Methane Hydrate Formation and Dissociation
LIU Chang-ling, YE Yu-guang, MENG Qing-guo, LV Wan-jun, and WANG Fei-fei
Micro laser Raman spectroscopic technique was used for in situ observation of the micro-processes of methane hydrate formed and decomposed in a high pressure transparent capillary. The changes in clathrate structure of methane hydrate were investigated during these processes. The results show that, during hydrate formaMicro laser Raman spectroscopic technique was used for in situ observation of the micro-processes of methane hydrate formed and decomposed in a high pressure transparent capillary. The changes in clathrate structure of methane hydrate were investigated during these processes. The results show that, during hydrate formation, the Raman peak(2 917 cm-1)of methane gas gradually splits into two peaks (2 905 and 2 915 cm-1) representing large and small cages, respectively, suggesting that the dissolved methane molecules go into two different chemical environments. In the meantime, the hydrogen bonds interaction is strengthened because water is changing from liquid to solid state gradually. As a result, the O—H stretching vibrations of water shift to lower wavenumber. During the decomposition process of methane hydrates, the Raman peaks of the methane molecules both in the large and small cages gradually clear up, and finally turn into a single peak of methane gas. The experimental results show that laser Raman spectroscopy can accurately demonstrate some relevant information of hydrate crystal structure changes during the formation and dissociation processes of methane hydrate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1524 (2011)
Raman Spectra Study of Barite at the Pressure of 0～1 GPa and Ambient Temperature
LIU Chuan-jiang, and ZHENG Hai-fei
The variation characters of Raman spectra of S—O symmetric stretching vibration ν987 and symmetric bending vibration ν452 and ν462 of barite at high pressure were studied using moissanite anvil cell. The experimental results show that barite is stable at the pressure of 0～1 GPa and ambient temperature, and the Raman peThe variation characters of Raman spectra of S—O symmetric stretching vibration ν987 and symmetric bending vibration ν452 and ν462 of barite at high pressure were studied using moissanite anvil cell. The experimental results show that barite is stable at the pressure of 0～1 GPa and ambient temperature, and the Raman peak positions of barite shift to higher frequency with increasing pressure. The relations between the Raman shifts and system pressure are given as follows: ν987=0.004 4p+987.42, ν452=0.002 3p+452.6, ν462=0.001 8p+462.42, and that stretching vibrations are more affected by pressure than bending vibrations. The intensity of 987 cm-1 Raman peak of barite is six times greater than that of 464 cm-1 Raman peak of quartz, so barite can be used as a good pressure gauge. Besides, the relation between the system pressure and Raman shift of 987 cm-1 peak position of barite is given as follows: p(MPa)=223.16×(Δνp)987－90.35(987 cm-1＜νp＜992 cm-1). The difference in the measured relative pressure-shift of the Raman line of the symmetric stretching vibration among various sulfate minerals shows the compressibility and strength of the S—O bond in the SO4 group..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1529 (2011)
Interaction of Lactoferrin and Its Peptides with DPPC and DPPG Liposomes Studied by Raman Spectroscopy
ZHANG Wei, REN Fa-zheng, GE Shao-yang, ZHANG Lu-da, JIANG Lu, MAO Xue-ying, and GUO Hui-yuan
Interaction of lactoferrin and its peptides LfcinB4-14 and LfampinB with dipalmitoylglycero-phosphocholine (DPPC) and dipalmitoylglycero-phosphoglycerol (DPPG) liposomes were studied by means of Raman spectroscopy. In our study, conformational changes in the phospholipid molecules were investigated by measuring the intInteraction of lactoferrin and its peptides LfcinB4-14 and LfampinB with dipalmitoylglycero-phosphocholine (DPPC) and dipalmitoylglycero-phosphoglycerol (DPPG) liposomes were studied by means of Raman spectroscopy. In our study, conformational changes in the phospholipid molecules were investigated by measuring the intensities of 2 847 and 2 882 cm-1 Raman bands which are assigned to acyl chains’ symmetric and asymmetric C—H stretching vibrations. The addition of lactoferrin and its peptides LfcinB4-14 and LfampinB caused a decrease in the 2 882 cm-1 intensity of DPPG liposomes, thus the order parameter for the lateral interactions between chains Slat decreased from 0.19 to 0.17, 0.14 and 0.12 respectively. On the contrary, the intensities at 2 847 and 2 882 cm-1 of DPPC liposomes were poorly affected by lactoferrin and its peptides. The results show that lactoferrin and its peptides present a stronger effect on the molecular structure and order degree of anionic lipid DPPG than that of zwitterionic lipid DPPC. This suggests that lactoferrin, LfcinB4-14 and LfampinB can interact and combine with the negatively charged DPPG liposomes by electrostatic interaction and perform its antibacterial activity. Besides, LfcinB4-14 and LfampinB can affect the lipid more strongly than lactoferrin..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1533 (2011)
Secondary Structure Changes of Insulin Induced by PEF Exposure at Different Temperatures Using Raman Spectra and Theoretical Model Analysis
PEI Jian, XIE Tao-rong, YAN Zhe, CHEN Shu-de, and QIAO Deng-jiang
Recently, biological effects induced by weak electromagnetic fields have been a public concern. Our previous study found temperature and electromagnetic field co-effects on insulin conformation. Therefore, in the present study, Raman spectroscopy was employed to investigate the secondary structure changes of insulin moRecently, biological effects induced by weak electromagnetic fields have been a public concern. Our previous study found temperature and electromagnetic field co-effects on insulin conformation. Therefore, in the present study, Raman spectroscopy was employed to investigate the secondary structure changes of insulin molecule induced by pulsed electric field (PEF) exposure at various temperatures. The content changes in alpha helix of insulin were obtained. Then, protein helix-random coil transition model was used to quantitatively study the experimental results. The theoretical model could figure out the effect of PEF on alpha helix contents of insulin at different temperatures. The protein secondary structure transits from helix to random coil evoked by PEF exposure and change of thermodynamic environment, which could explain the reason for the decline of alpha helix content of insulin caused by PEF exposure together with temperature rising. The results offer experimental basis and theoretical reference for further study of the mechanism of nonthermal effects of weak electromagnetic fields on biological molecule secondary structure..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1537 (2011)
Raman Scattering Calculations Studies of Malachitegreen Isothiocyanate
GUO Mo-ran, CAI Hong-xing, CHEN Gao, FAN Ya, and ZHANG Xi-he
Malachite green isothiocyanate(MGITC)is a Raman probe molecule that was applied to cells detection, tissue composition detection and cells stain imaging. In the present work, MGITC molecular structure was optimized by density functional theory(DFT) calculation. MGITC molecular Raman spectra and infrared spectra were caMalachite green isothiocyanate(MGITC)is a Raman probe molecule that was applied to cells detection, tissue composition detection and cells stain imaging. In the present work, MGITC molecular structure was optimized by density functional theory(DFT) calculation. MGITC molecular Raman spectra and infrared spectra were calculated with Hartree-Fork theory and MP2 theory based on STO-3G level, then two theoretical Raman spectra were carefully compared with experimental spectra, and good agreements were obtained between the theoretical and experimental results. MGITC structure parameters were given also in the paper including bond lengths and bond angles etc. Vibrational modes were assigned to all bands in the range between 550 and 4 200 cm-1. This work will facilitate the application of MGITC Raman probe for biology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1541 (2011)
Preparation and Study of a New Type Substrate for Raman Enhancement
WU Yong-jun, DONG Kun, FENG Chao, and ZHANG Peng-xiang
A highly ordered anodic aluminum oxide template was prepared, the mixture of phosphate and chromic acid was used to remove the oxide layer, regular pits array on the surface of the aluminum was obtained, then AC electrodeposit method was used to get fluffy nano silver structure, which was tested with SEM. Melamine was A highly ordered anodic aluminum oxide template was prepared, the mixture of phosphate and chromic acid was used to remove the oxide layer, regular pits array on the surface of the aluminum was obtained, then AC electrodeposit method was used to get fluffy nano silver structure, which was tested with SEM. Melamine was chosen as the probe molecule, the Raman peaks of melamine with 10-12 g·mL-1 were successfully detected, and the molecule number of the melamine is about 3.8×10-6 at this concentration and laser spot through calculation, which is beyond the detection level of monolayer. The enhancement factor reached 1.41×1011..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1545 (2011)
Study on the Vibrational Spectra Characters of Taiwan Blue Chalcedony
CHEN Quan-li, YUAN Xin-qiang, and JIA Lu
Blue chalcedony is one of the precious gems produced in Taiwan, known as “Taiwan Sapphire” in the world. The infrared absorption spectrum and Raman spectrum were employed to study the characters of the vibrational spectrum of the blue chalcedony with different color and texture. It was indicated that the Taiwan blue chBlue chalcedony is one of the precious gems produced in Taiwan, known as “Taiwan Sapphire” in the world. The infrared absorption spectrum and Raman spectrum were employed to study the characters of the vibrational spectrum of the blue chalcedony with different color and texture. It was indicated that the Taiwan blue chalcedony shows the typical spectral characteristics of the vibrational spectra of the quartziferous jade. The infrared absorption spectra show that the strongest absorption region 1 250～1 110 cm-1 is induced by Si—O asymmetric stretching vibration, the medium-intensity absorption band 800～600 cm-1 is mainly induced by the Si—O—Si symmetric stretching vibration and the Si—O bending vibration displays the peaks in the range of 600～300 cm-1. The Raman spectra scattering peaks of the Taiwan blue chalcedony samples are mainly at 499 cm-1±, 464 cm-1±, and 208～214 cm-1 and are mainly induced by the Si—O symmetric bending vibration, Si—O bending vibration, and ［SiO4］ rotational vibration or translation vibration of the “Moganite” quartz..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1549 (2011)
Research on Using a Mono-Window Algorithm for Land Surface Temperature Retrieval from Chinese Satellite for Environment and Natural Disaster Monitoring(HJ-1B) Data
ZHAO Shao-hua, QIN Qi-ming, ZHANG Feng, WANG Qiao, YAO Yun-jun, YOU Lin, JIANG Hong-bo, CUI Rong-bo, and YAO Yian-juan
Land surface temperature(LST) is a key parameter in earth environment, the thermal infrared band that can detect LST plays an important role in spectroscopy. Aiming to the latest optical and thermal bands of HJ-1B satellite, the LST retrieval over Ningxia plain was implemented using a mono-window algorithm without atmoLand surface temperature(LST) is a key parameter in earth environment, the thermal infrared band that can detect LST plays an important role in spectroscopy. Aiming to the latest optical and thermal bands of HJ-1B satellite, the LST retrieval over Ningxia plain was implemented using a mono-window algorithm without atmospheric water vapor content input, based on the COST model for atmospheric correction. Considering the difficulty of obtaining simultaneous ground measured data, the MODIS LST product was adopted as a standard to test the approach. The comparison and validation indicate that this method has good reliability with accuracy of less than 1 K. In addition, the sensitivity analysis is performed for land surface emissivity, and the result shows that this variable was not sensitive to LST, because the LST error is less than 0. 5 K when it varies at medium level. This study proves that the satellite data has higher availability for detecting LST..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1552 (2011)
New Index for Soil Moisture Monitoring Based on ΔTs-Albedo Spectral Information
YAO Yun-jun, QIN Qi-ming, ZHAO Shao-hua, SHEN Xin-yi, and SUI Xin-xin
Monitoring soil moisture by remote sensing has been an important problem for both agricultural drought monitoring and water resources management. In the present paper, we acquire the land surface temperature difference (ΔTs)and broadband albedo using MODIS Terra reflectance and land surface temperature products to consMonitoring soil moisture by remote sensing has been an important problem for both agricultural drought monitoring and water resources management. In the present paper, we acquire the land surface temperature difference (ΔTs)and broadband albedo using MODIS Terra reflectance and land surface temperature products to construct the ΔTs-albedo spectral feature space. According to the soil moisture variation in spectral feature space, we put forward a simple and practical temperature difference albedo drought index (TDADI) and validate it using ground-measured 0～10 cm averaged soil moisture of Ningxia plain. The results show that the coefficient of determination (R2) of both them varies from 0.36 to 0.52, and TDADI has higher accuracy than temperature albedo drought index (TADI) for soil moisture retrieval. The good agreement of TDADI, Albedo/LST, LST/NDVI and TVDI for analyzing the trends of soil moisture change supports the reliability of TDADI. However, TDADI has been designed only at Ningxia plain and still needs further validation in other regions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1557 (2011)
Fluorescence Properties of Urban Water Bodies of Beijing
WU Jing, CUI Shuo, SU Wei, and CAO Zhi-ping
“Fluorescence fingerprint” of water body based on fluorescence excitation-emission matrix has been a novel and valuable method to exhibit the organics details. In the present study, the fluorescence matrixes of urban water bodies of Beijing were investigated. The experimental results showed that these matrixes could be“Fluorescence fingerprint” of water body based on fluorescence excitation-emission matrix has been a novel and valuable method to exhibit the organics details. In the present study, the fluorescence matrixes of urban water bodies of Beijing were investigated. The experimental results showed that these matrixes could be divided into 3 groups: Type I owned two fluorescence centers, locating at λex/λem=275～280/340 and 225～230/340 nm respectively, and was the predominant group; fluorescence centers of Type Ⅱ located at λex/λem=280/345～365 and 245/380 nm; Type Ⅲ had four fluorescence centers around 275/305, 275/340, 225/305 and 225/340 nm. The fingerprints indicated that these water bodies had been disturbed by human activities. Type I and Type Ⅲ were transitional fingerprints between undisturbed water body and sewage wastewater and Type Ⅲ was closer to sewage wastewater. Type Ⅱ closely originated from reclaimed water of municipal wastewater treatment plant. These three types were main types of urban water bodies where domestic pollution was dominating. The fluorescence fingerprints clearly displayed the ubiquitous impacts of human activities and the resulting potential risk. Fluorescence fingerprint could display pollution information and serve as a possible diagnosis tool of pollution source..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1562 (2011)
Study on Fluorescence Measurement System of Wastewater Treatment Process
WU Zhi-xiang, WANG Jun-bo, LI Zhan-feng, and DENG Hu
The present paper, focusing on the relationship between the fluorescence characteristics of fluorescent substances produced by the anaerobic reactors in process of the wastewater treatment status, aims to build an online detection platform of anaerobic wastewater treatment process for the wastewater treatment process pThe present paper, focusing on the relationship between the fluorescence characteristics of fluorescent substances produced by the anaerobic reactors in process of the wastewater treatment status, aims to build an online detection platform of anaerobic wastewater treatment process for the wastewater treatment process parameter control, to provide effective, credible and stable technical basis, and to a certain extent can improve the efficiency of wastewater treatment. The results showed that it is feasible for this system to use fluorescence spectroscopy of wastewater treatment anaerobic reactor during the test; compared with the conventional detection method, it has simple structure, high sensitivity, and less time-consuming advantages; for other fluorescent substances in waste water treatment, it has broad application prospects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1567 (2011)
Effect of Temperature and pH on the Fluorescence Characteristic of Oily Waste Water
YI Li-li, SHANG Li-ping, LI Zhan-feng, and DENG Hu
The present study was about the effect of temperature (5~55 ℃) and pH(3~12) value on the fluorescence characteristic of oily waste water from the export of China Petroleum & Chemical Oil Refinery. It was found that temperature only affects the fluorescence intensity but not the site of fluorescence peaks. The fluorThe present study was about the effect of temperature (5~55 ℃) and pH(3~12) value on the fluorescence characteristic of oily waste water from the export of China Petroleum & Chemical Oil Refinery. It was found that temperature only affects the fluorescence intensity but not the site of fluorescence peaks. The fluorescence peaks shift right that from 413 to 426.5 nm when the oily waste water is acid. And along with the enhancing of the acidity the fluorescence intensity ascended. The fluorescence intensity decreased with alkaline enhancing but the site of fluorescence peaks remained unchanged at 398 nm. Temperature and pH value were the two important impact factors on the fluorescence characteristic of oily waste water. If desired it needs correction and compensation on temperature and pH value. That’s expected to improve the detection accuracy of oil class and content..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1571 (2011)
The Variation Trend of Fluorescence Characteristics of DOM in the Acetophenone Degradation Process by Electro-Fenton
LAI Bo, ZHOU Yue-xi, PANG Cui-cui, LIAN Yu, ZHANG Sheng, and ZHOU Ji-hong
In the acetophenone degradation process by electro-Fenton, the variation trend of fluorescence characteristics of dissolved organic matter (DOM) in acetophenone synthetic wastewater was detected by excitation-emission matrix (EEM)fluorescence spectra. The fluorescence spectra characteristics of acetophenone were studieIn the acetophenone degradation process by electro-Fenton, the variation trend of fluorescence characteristics of dissolved organic matter (DOM) in acetophenone synthetic wastewater was detected by excitation-emission matrix (EEM)fluorescence spectra. The fluorescence spectra characteristics of acetophenone were studied, and the fitting line of fluorescence intensity and acetophenone removal efficiency was discussed in detail. The results show that the locations of the two fluorescence centers of acetophenone synthetic wastewater are at λEx/Em=270/305 nm (Peak A) and λEx/Em=215/305 nm (Peak B), respectively, and the ratio of Peak A/Peak B is 1.22. In the electro-Fenton treatment process, firstly, acetophenone was decomposed into unsaturated fatty acid which had stronger fluorescence intensity, further, it was degraded into short-chain small molecular compounds which have weaker fluorescence intensity. Therefore, the fluorescence intensity of synthetic wastewater was increased at first and decreased afterwards in the entire 180 min electro-Fenton treatment process. The two-dimensional fluorescence peak at 285～375 nm of emission wavelength (at λEx=250 nm) had a good linear relationship with the removal efficiency of acetophenone, therefore, it could reflect effectively the removal efficiency of acetophenone in the whole electro-Fenton treatment process..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1574 (2011)
Application of Fluorescence Spectroscopy in Studying the Protective Function of 11-Amino Acid Motif of Group3 Late Embryogenesis Abundant Protein
LIU Yun, DENG Yin-xia, ZHANG Yu-qin, XU Hong, and ZHENG Yi-zhi
Late embryogenesis abundant protein (LEA) can enhance the tolerance of organisms under drought, low-temperature and other stress conditions. However, their protection mechanisms are still unclear. In the present paper, the peptides consisting of multi-copies of 11-amino acid motif, such as PM2D and PM2E are proved to pLate embryogenesis abundant protein (LEA) can enhance the tolerance of organisms under drought, low-temperature and other stress conditions. However, their protection mechanisms are still unclear. In the present paper, the peptides consisting of multi-copies of 11-amino acid motif, such as PM2D and PM2E are proved to protect the activity of the lactate dehydrogenase (LDH) from freeze-thaw by using ultroviolet spectrometry. Furthermore, the fluorescence spectroscopic results show that the peptide consisting of multi-copies of 11-amino acid can stabilize the structure of LDH through synergy and multi-sites binding. However, the peptides consisting of less copies of 11-amino acid, such as PM2F and PM2G bind to LDH through one site, and the binding is weak. They thus can not protect the activity of LDH. In addition, the peptides consisted of multi-copies of 11-amino acid protect LDH by acting with trehalose synergically, and the protection mechanisms of LEA and trehalose on LDH are different..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1579 (2011)
Interaction of Cucurbit［n=7, 8］ with Methylindoles via Fluorescence Spectroscopy
HOU Hua-li, XUE Sai-feng*, MU Lan, and TAO Zhu
In the present work, the authors investigated interaction of cucurbit［n=7, 8］urils(Q, Q) with 2-methylindol(Me) and 3-methylindol(Sk), influences of pH and temperature on the interaction of Q, Q with the guests and calculations of the stability constants and thermodynamic parameters by using fluorescence spctroscopy. TIn the present work, the authors investigated interaction of cucurbit［n=7, 8］urils(Q<参考文献原文>, Q<参考文献原文>) with 2-methylindol(Me) and 3-methylindol(Sk), influences of pH and temperature on the interaction of Q<参考文献原文>, Q<参考文献原文> with the guests and calculations of the stability constants and thermodynamic parameters by using fluorescence spctroscopy. The results show that: the interation ratios are 1∶1 of host: guest for all systems, except the Q<参考文献原文>-Sk system, for which the ratio is 1∶2 of host: guest; the interaction ratios of the host: guest systems did not change in the range of pH 1~11 and temperature between 298 and 313 K; the stability constant is the largest at pH 1 and room temperature. The thermodynamic parameter revealed that the interaction of the host and the guest of spontaneitied..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1585 (2011)
The Spectroscopic Properties of a New Rhodamine B Schiff-Base Fluorescent Derivative
ZHANG Ling-fei, ZHAO Jiang-lin, ZENG Xi, MU Lan, and WEI Gang
A derivative with Schiff-base structure was synthesized. Fluorescence and visible absorption spectra show that the presence of Fe3+ induces the formation of a Fe3+ complex, observing significant enhancement of fluorescence and absorption. The results show that the derivative is not only a good fluorescence and colorimeA derivative with Schiff-base structure was synthesized. Fluorescence and visible absorption spectra show that the presence of Fe3+ induces the formation of a Fe3+ complex, observing significant enhancement of fluorescence and absorption. The results show that the derivative is not only a good fluorescence and colorimetric chemosensor for Fe3+, but also a metal complex fluorescent probe for BSA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1591 (2011)
Determination of Cetirizine Dihydrochloride by Anti-Fluorescence Quenching on Rhodamine B-Sodium Tetraphenylborate System
WEI Xiao-ling, LEI Xiang-rong, GONG Qi, WANG Li-sheng, and LIAO Yuan
The sodium tetraphenylboron has the fluorescence quenching effect on rhodamine B, making the fluorescence signal intensity weaken or even disappear. But cetirizine dihydrochloride has the anti-quenching effect on rhodamine B-the fluorescence signal is enhanced, and there was a linear relationship between the fluorescenThe sodium tetraphenylboron has the fluorescence quenching effect on rhodamine B, making the fluorescence signal intensity weaken or even disappear. But cetirizine dihydrochloride has the anti-quenching effect on rhodamine B-the fluorescence signal is enhanced, and there was a linear relationship between the fluorescence signal enhancement degree and drug concentrationt. In the present paper, 491 and 610 nm were chosen as the excitation and emission wavelength for measurement of the fluorescence intensity difference ΔF=F1-F0 of blank solution and test solution, and according to positive correlation between the value of ΔF and cetirizine hydrochloride concentration of test solution, a new method of anti-fluorescence quenching for the determination of cetirizine hydrochloride was established. The linear regression equation was ΔF=0.727 5m-2.357, correlation coefficient was 0.997 2, linear range was 3.50～129.3 mg·L-1, the detection limit was 1.05 mg·L-1 and RSD was 1.2%. The cetirizine hydrochloride tablets and cetirizine hydrochloride capsules from different manufacturers were determined by this method, the measured values were basically in line with the labeled amount of drugs, and the recovery rate was between 92% and 106%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1596 (2011)
Spectroscopic Studies on the Interaction of Elsinochrome A with Myoglobin
MA Fei, ZHOU Lin, WANG Wei, FENG Yu-ying, ZHOU Jia-hong, WANG Xing-he, and SHEN Jian
The interaction between Elsinochrome A (EA) and myoglobin (Mb) was investigated using UV-Vis and fluorescence spectroscopy. The results suggested that there was a strong interaction between EA and Mb. In the dark, the interaction occurred on the surfaces amidic acid of Mb, but when illuminated, the interactions happeneThe interaction between Elsinochrome A (EA) and myoglobin (Mb) was investigated using UV-Vis and fluorescence spectroscopy. The results suggested that there was a strong interaction between EA and Mb. In the dark, the interaction occurred on the surfaces amidic acid of Mb, but when illuminated, the interactions happened both on amidic acid and the interior structure of hemachrome of Mb. According to the values of the quenching constant, the thermodynamics parameters, the binding constants and the binding sites, it was showed that the binding interaction of EA and Mb was mainly hydrophobic in nature and the quenching mechanism was static quenching procedure. The change in the micro-circumstance of aminos of myoglobin was studied by synchronous fluorescence spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1601 (2011)
Investigation of Material Structure and Optical Property of Transmission-Mode GaN Photocathode by Ultraviolet Transmission Spectral
DU Xiao-qing, TIAN Jian, and ZHOU Qiang-fu
GaN UV photocathode has become a high-performance vacuum ultraviolet detectors in recent years. As the photocathode practical application mode, transmission-type multilayer structure and its optical property have important influences on photocathode photoemission performance. Ultraviolet transmission spectra of transmiGaN UV photocathode has become a high-performance vacuum ultraviolet detectors in recent years. As the photocathode practical application mode, transmission-type multilayer structure and its optical property have important influences on photocathode photoemission performance. Ultraviolet transmission spectra of transmission-mode GaN photocathode were measured. The optical transmission model of transmission-mode GaN photocathode was built, and based on the model the functional relations of thin film thickness and optical adsorption coefficient with transmission spectral were deduced. The error of calculated GaN epitaxial thickness with respect to actual value is very small, and calculated adsorption coefficients are consistent with reported data. It was shown that material structure and optical property of transmission-mode GaN photocathode can be evaluated accurately by this ultraviolet transmission spectral method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1606 (2011)
Spectrometric Study on the Effect of Denaturant on the Conformation of Tartary Buckwheat Protein
GUO Xiao-na, and YAO Hui-yuan
The effect of ethanol and GuHCl solution on the structure of tartary buckwheat protein(TBWSP31)was studied by UV differential absorption and fluorescence emission spectra. The alcohol denaturation of TBWSP31 was a kind of partial denaturation. The hydrophobic core of TBWSP31 remained intact and the conformation of the The effect of ethanol and GuHCl solution on the structure of tartary buckwheat protein(TBWSP31)was studied by UV differential absorption and fluorescence emission spectra. The alcohol denaturation of TBWSP31 was a kind of partial denaturation. The hydrophobic core of TBWSP31 remained intact and the conformation of the hydrophilic shell was changed. When TBWSP31 was denatured by GuHCl solution with higher concentration, Tyr and Trp residues were exposed to the polar aqueous solvents from the hydrophobic core, and the microenvironment showed a great change..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1611 (2011)
Study on the Method of Recognizing Abandoned Farmlands Based on Multispectral Remote Sensing
CHENG Wei-fang, ZHOU Yi, WANG Shi-xin, HAN Yu, WANG Fu-tao, and PU Qing-yang
Being abandoned for farmland seriously affected China’s grain output for farmlands. It has become an important phenomenon over the past 20 years in China. Multispectral remote sensing has the advantage of wide range and high speed in requiring data. It has great potential in the research on land use. Therefore, to extrBeing abandoned for farmland seriously affected China’s grain output for farmlands. It has become an important phenomenon over the past 20 years in China. Multispectral remote sensing has the advantage of wide range and high speed in requiring data. It has great potential in the research on land use. Therefore, to extract abandoned farmland in China, the authors’ used the NDVI data of Modis/Terra from 2000 to 2009 which is one of multispectral remote sensing data and the Remote Sensing Image of ALOS satellite in Japan. The authors’ used the parameter of NDVI of time series to describe the character of the main land use types. After drawing the time-series curves of the main land use type samples, the authors’ analyzed them with consulting the life character of these types. Then, the authors’ compared these curves; finally we recognized abandoned farmland from the others. At last the authors’ went to experimental plot to survey the land use. The results demonstrated that the method of using multispectral remote sensing data can abstract abandoned farmland and classify the main kind of land use, and the accuracy is as high as 90%. So the method is feasible in recognizing abandoned farmland..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1615 (2011)
Indication of the Expression of Transgene in Rice Plant Based on Hyperspectral Remote Sensing Technique Ⅱ——Growth Monitoring of Samples in the Contrast Experiment
LI Ru, CHEN Jin-song, YUAN Ding-yang, LIN Hui, TAN Yan-ning, and YUE Yue-min
Since the complication of monitoring and evaluating the problems about the transgenic expression and its impacts on the receptor in the transgenic crop breeding and other relevant evaluated works, the authors in the present work tried to assess the differences of spectral parameters of the transgenic rice in contrast wSince the complication of monitoring and evaluating the problems about the transgenic expression and its impacts on the receptor in the transgenic crop breeding and other relevant evaluated works, the authors in the present work tried to assess the differences of spectral parameters of the transgenic rice in contrast with its parent group quantitatively and qualitatively, fulfilling the growth monitoring of the transgenic samples. The spectral parameters (spectral morphological characteristics and indices) chosen are highly related to internal or external stresses to the receipts, and thus could be applied as indicators of biophysical or biochemical processes changes of plant. By ASD portable field spectroradiometer with high-density probe, fine foliar spectra of 8 groups were obtained. By analyzing spectral angle and continuum removal, the spectral morphological differences and their locations of sample spectra were found which could be as auxiliary priori knowledge for quantitative analysis. By investigating spectral indices of the samples, the quantitative differences of spectra were revealed about foliar chlorophyll a+b and carotenoid content. In this study both the spectral differences between transgenic and parent groups and among transgenic groups were investigated. The results show that hyperspectral technique is promising and a helpful auxiliary tool in the study of monitoring the transgenic crop and other relevant researches. By this technique, quantitative and qualitative results of sample spectra could be provided as prior knowledge, as certain orientation, for laboratory professional advanced transgenic breeding study.*Corresponding author.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1621 (2011)
Stereoscopic Remote Sensing Used in Monitoring Enteromorpha Prolifra Disaster in Chinese Yellow Sea
GU Xing-fa, CHEN Xing-feng, YIN Qiu, LI Zheng-qiang, XU Hua, SHAO Yun, and LI Zi-wei
In the summer 2008, Enteromorpha Prolifra broke out in Yellow Sea and East Sea on a large scale for the first time, and became a marine disaster. The authors constructed a stereoscopic monitoring system which monitored the disaster continuously, dynamically and in real time. The present paper introduced the constructioIn the summer 2008, Enteromorpha Prolifra broke out in Yellow Sea and East Sea on a large scale for the first time, and became a marine disaster. The authors constructed a stereoscopic monitoring system which monitored the disaster continuously, dynamically and in real time. The present paper introduced the construction of the stereoscopic monitoring system; through analyzing the spectral characteristics of Enteromorpha Prolifra and ocean water which were acquired in a field experiment, confirmed Enteromorpha Prolifra retrieval models based on multi-platform multi-sensor and multi-spectral remote sensing data, contrasted the different scale monitoring results, and analyzed the evolvement rules with time-series analysis. This system was applied to the Enteromorpha Prolifra emergency monitoring in the 29th Olympic sailing area. It was proved feasible and valuable for the Olympic safeguard..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1627 (2011)
Analysis of Lop Nur “Ear” Features in Remote Sensing Image and Its Environmental Meaning
CAI Ai-min, SHAO Yun, GONG Hua-ze, WANG Guo-jun, and XIE Chou
There is a great significance of revealing the characteristics of regional environment evolution and global change to the research on arid Lop Nur areas. By the “Ear” features of Lop Nur in remote sensing image, the spectrum, soil and surface parameters were analyzed. The differences in total salt content in soil and tThere is a great significance of revealing the characteristics of regional environment evolution and global change to the research on arid Lop Nur areas. By the “Ear” features of Lop Nur in remote sensing image, the spectrum, soil and surface parameters were analyzed. The differences in total salt content in soil and the surface structure bring are cause directly for the “Ear” features in remote sensing image; The results of the analysis of spectrum, total salt content and particle size are in good agreement. “Ear” features recorded the process of environmental change. The process implys that Lop Nur dried up gradually under the impact of global change. The adjustment during the process of drying up let Lop Nur experience two relatively humid climates, with the previous a little longer, the later very short..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1633 (2011)
Mineral Information Extraction for Hyperspectral Image Based on Modified Spectral Feature Fitting Algorithm
XU Ning, HU Yu-xin, LEI Bin, HONG You-tang, and DANG Fu-xing
Spectral feature fitting (SFF) algorithm has been frequently used since 1990s. A modified spectral feature fitting method is introduced here, which can solve some drawback of the general algorithm. The method mentioned here combines SFF with user-defined constraints in spectral absorption feature to extract more accuraSpectral feature fitting (SFF) algorithm has been frequently used since 1990s. A modified spectral feature fitting method is introduced here, which can solve some drawback of the general algorithm. The method mentioned here combines SFF with user-defined constraints in spectral absorption feature to extract more accurate target information from hyperspectral image. Two experiments are presented herein, in which three algorithms are used to obtain mineral information from hyperspectral data with different space resolution and SNR. Muscovite, calcite and chlorite etc. are extracted by general SFF, modified SFF and spectral angle mapping (SAM) respectively, and the result indicates that modified SFF algorithm is more effective in differentiating subtle spectral feature and obtaining accurate mineral information. The experiments also demonstrate that the algorithm mentioned here is validated in mineral information extraction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1639 (2011)
Monitoring “Green Tide” in the Yellow Sea and the East China Sea Using Multi-Temporal and Multi-Source Remote Sensing Images
XING Qian-guo, ZHENG Xiang-yang, SHI Ping, HAO Jia-jia, YU Ding-feng, LIANG Shou-zhen, LIU Dong-yan, and ZHANG Yuan-zhi
Landsat-TM (Theme Mapper) and EOS (Earth Observing System)-MODIS (MODerate resolution Imaging Spectroradiometer) Terra/Aqua images were used to monitor the macro-algae (Ulva prolifera) bloom since 2007 at the Yellow Sea and the East China Sea. At the turbid waters of Northern Jiangsu Shoal, there is strong spectral mixLandsat-TM (Theme Mapper) and EOS (Earth Observing System)-MODIS (MODerate resolution Imaging Spectroradiometer) Terra/Aqua images were used to monitor the macro-algae (Ulva prolifera) bloom since 2007 at the Yellow Sea and the East China Sea. At the turbid waters of Northern Jiangsu Shoal, there is strong spectral mixing behavior, and satellite images with finer spatical resolution are more effective in detection of macro-algae patches. Macro-algae patches were detected by the Landsat images for the first time at the Sheyang estuary where is dominated by very turbid waters. The MODIS images showed that the macro-algae from the turbid waters near the Northern Jiangsu Shoal drifted southwardly in the early of May and affected the East China Sea waters; with the strengthening east-asian Summer Monsoon, macro-algae patches mainly drifted in a northward path which was mostly observed at the Yellow Sea. Macro-algae patches were also found to drift eastwardly towards the Korea Peninsular, which are supposed to be driven by the sea surface wind..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1644 (2011)
Simulation and Analysis of Polarization Characteristics for Real Sea Surface Sunglint
CHEN Xing-feng, GU Xing-fa, CHENG Tian-hai, LI Zheng-qiang, YU Tao, and XIE Dong-hai
The sea surface sunglint is caused by specular reflectance. Water is a kind of dark target with a very low reflectance, so sunglint becomes a big noise in the aerial or aerospace remote sensing images; sunglint is strongly polarized, and can be a natural standard light source for polarized sensor in-flight calibration;The sea surface sunglint is caused by specular reflectance. Water is a kind of dark target with a very low reflectance, so sunglint becomes a big noise in the aerial or aerospace remote sensing images; sunglint is strongly polarized, and can be a natural standard light source for polarized sensor in-flight calibration; sunglint also can be utilized to retrieve gaseous constituents and aerosol properties. For both de-noising and being standard light source, the radiative physic parameters should be calculated accurately. First, A 3-D sea surface model was constituted according to the Cox & Munk model; Second, the polarized radiative model of sunglint was deduced based on the 3-D sea surface model and polarized Fresnel reflectance law; Third, the sensitivities of solar-viewing relative azimuth, zenith, wind speed and wind direction were analyzed utilizing the polarized radiative model. The polarization characteristics analysis of sunglint provides a theoretical basis for the quantitative remote sensing retrievals which uses sunglint..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1648 (2011)
High Speed Transmission System for Dual-Spectral Remote Sensing System
[in Chinese], [in Chinese], and [in Chinese]
In order to realize dual-spectral aerial camera image data transmission, a novel optical transmission system is proposed, then transmission scheme, structure of data frame and timing recovery method are discussed thoroughly. First, valid data in one line are picked up from two detectors before transmitting, a timing reIn order to realize dual-spectral aerial camera image data transmission, a novel optical transmission system is proposed, then transmission scheme, structure of data frame and timing recovery method are discussed thoroughly. First, valid data in one line are picked up from two detectors before transmitting, a timing recovery method which makes in-out data timing and format consistent, is proposed using line valid interrupt flag. Second, based on transmitting and receiving buffering mechanism, dual asynchronous detectors data are transmitted in a single fiber. Third, transmitting and receiving systems are implemented using large programmable devices which embeds high speed data interface. Finally, behavioral and system verification method is proposed as well. Experimental results indicate that the system could support full, median and base cameral link protocol, serial data transmitting speed could be 6.25 Gb·s-1, and pixel data rate is 40 MHz at most for two detectors. It is very suitable for space and serial remote sensing equipment due to its compact and high reliable structure..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1654 (2011)
Wheat Leaf Area Index Inversion Using Hyperspectral Remote Sensing Technology
LIANG Liang, YANG Min-hua, ZHANG Lian-peng, and LIN Hui
The wheat leaf area index (LAI) was inverted using hyperspectral remote sensing technology in the present paper. Eighteen kinds of hyperspectral indices were comparatively analyzed, and the index OSAVI, which could reflect wheat LAI most sensitively, was screened out. The models for wheat LAI inversion were built usingThe wheat leaf area index (LAI) was inverted using hyperspectral remote sensing technology in the present paper. Eighteen kinds of hyperspectral indices were comparatively analyzed, and the index OSAVI, which could reflect wheat LAI most sensitively, was screened out. The models for wheat LAI inversion were built using the field spectra as the training samples. The study showed that the calibration R-square and prediction R-square of the inversion model which were built by hyperspectral index OSAVI were 0.823 and 0.818, respectively, higher than that of other indices, indicating that the accuracy was highest. The inversion model was spatially quantitatively expressed in OMIS image, and then the inversion value and measured value was compared by the method of regression fitting. The R-square and RMSE of the fitting model were 0.756 and 0.500, respectively, indicating that the similarity between the inversion value and measured value was high. The result showed that it was feasible to invert the wheat LAI by hyperspectral indices, and OSVAI was an optimal one..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1658 (2011)
Studies on Characterization of Humic Acids Extracted from Sediments in Chongqing Section of the Jialingjiang River
LUO Gu-yuan, ZHU Hong, XU Xiao-yi, CAI Wen-liang, and DU Xian
Humic acids (HAs) were extracted from sediments of different segments in the Jialingjiang River. Fluorescence spectroscopy, elemental analysis and Fourier transform infrared (FTIR) spectrometry were used to investigate the chemical composition and structure characteristics of HAs. Elemental analysis showed that H/C, O/Humic acids (HAs) were extracted from sediments of different segments in the Jialingjiang River. Fluorescence spectroscopy, elemental analysis and Fourier transform infrared (FTIR) spectrometry were used to investigate the chemical composition and structure characteristics of HAs. Elemental analysis showed that H/C, O/C, and C/N molar rations were significantly different among 4 HAs, which indicated their differences in chemical composition and structure characteristics. FTIR spectra revealed that HAs contained more carboxyl, hydroxyl and carbonyl functional groups, and aromatic structure was very obvious. The three dimensional fluorescence excitation-emission-matrix (3DEEM) spectra of HAs presented two main peaks (peak a and peak b) at Ex/Em=270/390 nm and Ex/Em=230/350 nm. The relative fluorescence intensities Ia/Ib varied from 1.31 to 2.53 for different HA samples, which revealed that they contained multiple molecule fluorophores. Fluorescence index (f450/500=1.43～1.53) suggested that HAs mainly originated from terrestrial sources..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1663 (2011)
Design of Plant Leaf Bionic Camouflage Materials Based on Spectral Analysis
YANG Yu-jie, LIU Zhi-ming, HU Bi-ru, and WU Wen-jian
The influence of structure parameters and contents of plant leaves on their reflectance spectra was analyzed using the PROSPECT model. The result showed that the bionic camouflage materials should be provided with coarse surface and spongy inner structure, the refractive index of main content must be close to that of pThe influence of structure parameters and contents of plant leaves on their reflectance spectra was analyzed using the PROSPECT model. The result showed that the bionic camouflage materials should be provided with coarse surface and spongy inner structure, the refractive index of main content must be close to that of plant leaves, the contents of materials should contain chlorophyll and water, and the content of C—H bond must be strictly controlled. Based on the analysis above, a novel camouflage material, which was constituted by coarse transparent waterproof surface, chlorophyll, water and spongy material, was designed. The result of verifiable experiment showed that the reflectance spectra of camouflage material exhibited the same characteristics as those of plant leaves. The similarity coefficient of reflectance spectrum of the camouflage material and camphor leaves was 0.988 1, and the characteristics of camouflage material did not change after sunlight treatment for three months. The bionic camouflage material, who exhibited a high spectral similarity with plant leaves and a good weather resistance, will be an available method for reconnaissance of hyperspectral imaging hopefully..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1668 (2011)
Analysis of Mixed Alkane Gas Based on Tikhonov Regularization Spectra Selection and Optimal Neural Network Parameters Selection
TANG Xiao-jun, HAO Hui-min, LI Yu-jun, and LIU Jun-hua
Feature variable selection and modeling are two of the most principal research contents in spectral analysis. In the present paper, beginning from the introduction of feature spectrum selection based on Tikhonov regularization and discussion on it's application in multi-component mixed alkane gas analysis, 7 sets oFeature variable selection and modeling are two of the most principal research contents in spectral analysis. In the present paper, beginning from the introduction of feature spectrum selection based on Tikhonov regularization and discussion on it's application in multi-component mixed alkane gas analysis, 7 sets of feature spectra were abstracted from the absorption spectra of 7 kinds of alkane gas, including methane, ethane, propane, iso-butane, n-butane, iso-pentane and n-pentane. In order to overcome the problem of over-training of neural network, a method called optimal parameter selection of neural netework(NN) was presented to build analysis model of analyte. Optimal parameters were selected from many trained networks with same architecture based on error process. And analysis models of spectral analysis for 7 kinds of alkane gas were built. Finally, the testing analysis results done with standard gases are given. The results show that the method presented in this paper can be used to reduce the cross-sensitivity between any two kinds of gas. The cross-sensitivity is less than 0.5%. The resolving power is as high as 20×10-6..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1673 (2011)
A Novel SMOreg Algorithm Based on Instance Cloned and Its Research on Spectral Modeling for Hydromica in Uranium Deposit
WU Jia, CAI Zhi-hua, GAO Zhe-chao, and YU Chao
Hydromica is a typical alteration mineral in granite-type uranium deposit, and also an important indication of uranium. The amount of hydromica to some extent reflects the strength of hydromicasization in uranium deposit. Because of the bad performance of the traditional modelling methods in prediction, in the present Hydromica is a typical alteration mineral in granite-type uranium deposit, and also an important indication of uranium. The amount of hydromica to some extent reflects the strength of hydromicasization in uranium deposit. Because of the bad performance of the traditional modelling methods in prediction, in the present paper, the authors’ adopt SMOreg in the spectral modelling for hydromica, and validate its effectiveness. The authors’ also propose a novel method called ICSMOreg. In this method the authors’ employ instance cloned method to learn the samples selected by having a strong affinity with the test sets, and then get the new samples into SMOreg to build the spectral model. Finally, we experimentally compare ICSMOreg with SMOreg, artificial neural network, model tree and the common modelling methods like linear regression, multiple linear regression. The result shows that the new method improves the accuracy of prediction, and also reduces the negative impact of noise..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1678 (2011)
Study on the Effect of Solar Spectra on the Retrieval of Atmospheric CO2 Concentration Using High Resolution Absorption Spectra
HU Zhen-hua, HUANG Teng, WANG Ying-ping, DING Lei, ZHENG Hai-yang, and FANG Li
Taking solar source as radiation in the near-infrared high-resolution absorption spectrum is widely used in remote sensing of atmospheric parameters. The present paper will take retrieval of the concentration of CO2 for example, and study the effect of solar spectra resolution. Retrieving concentrations of CO2 by usingTaking solar source as radiation in the near-infrared high-resolution absorption spectrum is widely used in remote sensing of atmospheric parameters. The present paper will take retrieval of the concentration of CO2 for example, and study the effect of solar spectra resolution. Retrieving concentrations of CO2 by using high resolution absorption spectra, a method which uses the program provided by AER to calculate the solar spectra at the top of atmosphere as radiation and combine with the HRATS (high resolution atmospheric transmission simulation) to simulate retrieving concentration of CO2. Numerical simulation shows that the accuracy of solar spectrum is important to retrieval, especially in the hyper-resolution spectral retrieavl, and the error of retrieval concentration has poor linear relation with the resolution of observation, but there is a tendency that the decrease in the resolution requires low resolution of solar spectrum. In order to retrieve the concentration of CO2 of atmosphere, the authors’ should take full advantage of high-resolution solar spectrum at the top of atmosphere..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1683 (2011)
Study of the Over-Fitting in Building PLS Model Using Orthogonal Signal Correction
ZHANG Xian, YUAN Hong-fu, GUO Zheng, SONG Chun-feng, LI Xiao-yu, and XIE Jin-chun
In the present paper, the over-fitting phenomenon in building PLS model using orthogonal signal correction (OSC) was studied through establishment of quantitative calibration models for the peanut oil content in blending edible oils, and for the dimethylsulfoxide concentration in water solution. The cross validation reIn the present paper, the over-fitting phenomenon in building PLS model using orthogonal signal correction (OSC) was studied through establishment of quantitative calibration models for the peanut oil content in blending edible oils, and for the dimethylsulfoxide concentration in water solution. The cross validation results and the predication results of PLS models using OSC and without using OSC were compared to evaluate the effectiveness of OSC for improving the performance of PLS1 model. The results show that the application of OSC to PLS modeling will lead to an over-fitting phenomenon. According to the principles of their algorithms, when OSC and PLS are used together, the signals which are not correlated to the interested property are removed twice from the raw spectra. This leads to deleting the parts of useful information in spectra, and to spoiling the predictive ability of PLS models to some extent..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1688 (2011)
The Research on Active Constituent Distribution of Rhizoma Coptidis Pieces
ZHAO Jing, PANG Qi-chang, MA Ji, HU Cui-ying, WANG Nian-ping, WANG Lin, and CUI Dai-jun
In order to test the distribution of active constituent of traditional Chinese medicine and to evaluate the quality of medicinal part effectively, spectral imaging analysis technology was used, and rhizoma coptidis pieces were tested as an example. First, the fluorescence spectral cube was taken, and the spectral curveIn order to test the distribution of active constituent of traditional Chinese medicine and to evaluate the quality of medicinal part effectively, spectral imaging analysis technology was used, and rhizoma coptidis pieces were tested as an example. First, the fluorescence spectral cube was taken, and the spectral curve of 3 different medicinal parts of the piece was obtained; second, spectral images were reconstructed by principal components analysis method, and the differences of 3 medicinal parts on the first few principal components were focused; third, the first component image was divided by the threshold method, then the distribution and relative content of 3 medicinal parts were obtained. The results show that spectral imaging analysis technology can provide the distribution of the active constituent, which can be used as the criterion of selecting medicinal parts. The testing course is nondestructive and rapid..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1692 (2011)
Experimental Investigation of Quantitatively Analysing Trace Mo in Complex Metallic Alloys by Laser Induced Breakdown Spectroscopy
WANG Zhen-nan, LI Ying, ZHANG Qing-yu, LU Yuan, and ZHENG Rong-er
The quantitative analysis using laser induced breakdown spectroscopy (LIBS), lack of appropriate interior label element, is described and applied to trace element molybdenum (Mo) detection in complex metallic alloys. A Q-switched Nd∶YAG laser operating at 532 nm was utilized to generate plasma and the emission was recoThe quantitative analysis using laser induced breakdown spectroscopy (LIBS), lack of appropriate interior label element, is described and applied to trace element molybdenum (Mo) detection in complex metallic alloys. A Q-switched Nd∶YAG laser operating at 532 nm was utilized to generate plasma and the emission was recorded by a grating spectrometer equipped with CCD, boxcar and PMT. The three peak heights of Mo Ⅰ, 550.649, 553.305 and 557.045 nm, changing with Mo mass fraction in metallic alloys were measured to produce calibration curves respectively, and double blind method was used to analyse a test sample. Based on Mo Ⅰ 550.649 nm line, the Mo mass fraction in the test sample was determined to be 2.229% with relative error of 5.57% in comparison with the given value of 2.111%. On using Mo Ⅰ 557.045 nm line, the relative error was found to be doubled due to the overlap with Fe emission lines. While taking the total height of three atomic lines into account in analysis, the resulted error dropped to 7.58%, even better than the average of predicted concentrations based on the above three lines. The obtained results demonstrate that satisfactory precision could be obtained under a consistent experiment condition with the above scheme, even without appropriate interior label element. The methods of maintaining stable laser ablation efficiency on sample are also discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1697 (2011)
Preparation of Pb2+ Imprinted Acrylic Acid-co-Styrene and Analysis of Its Adsorption Properties by FAAS
Shawket Abliz, Abdiryim Supahun, WANG Ji-de, and Ismayil Nurulla
With lead ion template, acrylic acid as functional monomer, potassium persulfate as initiator,strytrene as framework monomer, lead ion imprinted polymers(Pb(Ⅱ)-IIPs) were prepared using free emulsion polymerization method. The structure and morphology of the polymers were analyzed by UV-spectra, FTIR and scanning electWith lead ion template, acrylic acid as functional monomer, potassium persulfate as initiator,strytrene as framework monomer, lead ion imprinted polymers(Pb(Ⅱ)-IIPs) were prepared using free emulsion polymerization method. The structure and morphology of the polymers were analyzed by UV-spectra, FTIR and scanning electron microscopy. The adsorption/desorption and selectivity for Pb2+ were investigated by flame atomic absorption spectrometry (FAAS) as the detection means. The results show that compared with non-imprinted polymers(NIPs), the Pb(Ⅱ)-IIPs had higher specific adsorption properties and selective recognition ability for Pb(Ⅱ). The relative selectivity coefficient of Pb(Ⅱ)-IIPs for Pb(Ⅱ) was 6.25, 6.18, 6.25 and 6.38 in the presence of Cd(Ⅱ), Cu(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) interferences, respectively. The absorption rate was the best at the pH of adsorbent solution of 6, Adsorption rate reached 96% during the 2.5 h static adsorption time. Using 3.0 mol·L-1 HCl as the best desorption solvent to desorb the adsorbents, the desorbtion rate reached 98%. Under the best adsorption conditions, the adsorption capacity of Pb(Ⅱ)-IIPs for Pb(Ⅱ) was found to be 40. mg·g.-1.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1702 (2011)
Boundary Threshold Value Method Used in Crystalline Material Internal Defect Detection by Short Wavelength X-Ray Diffraction
MU Jian-lei, ZHANG Jin, GAO Zheng-huan, ZHENG Lin, and HE Chang-guang
There are few references about crystalline material internal defect detected by X-ray diffraction tomography using common X-ray source. Short wavelength X-ray diffractometer (SWXRD), invented by Institute of Southwest Technology Engineering, is a relatively small and inexpensive instrument compared to synchrotron radiaThere are few references about crystalline material internal defect detected by X-ray diffraction tomography using common X-ray source. Short wavelength X-ray diffractometer (SWXRD), invented by Institute of Southwest Technology Engineering, is a relatively small and inexpensive instrument compared to synchrotron radiation or neutron reactor. Boundary determination of defect affects the imaging quality and the distinguishing of defect in X-ray diffraction tomography using SWXRD. In the present paper, threshold value method of diffracted intensity is put forward to process the test data, so the boundary of defect is legible. In order to study how the factors influence the threshold value, Gauss function is used in fitting the test data. The influence of varisized image quality indicator pressed in powdered aluminum on threshold value has been studied. The result shows that 91% of the diffraction intensity of substrate can be regarded as the threshold value. The experiment of slit in aluminum alloy sheet further verified the threshold value method. It’s useful in detecting the defect boundary..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1712 (2011)
Study on Bamboo Treated with γ Rays by X-Ray Diffraction
SUN Feng-bo, FEI Ben-hua, JIANG Ze-hui, YU Zi-xuan, TIAN Gen-lin, and YANG Quan-wen
The microfibril angle and crystallinity of bamboo treated with γ rays were tested by X-ray diffraction (XRD). The result indicated that crystallinity in bamboo increased when irradiation dose was less than 100 kGy, while the irradiation dose was raised to about 100 kGy, crystallinity in bamboo reduced. But during the wThe microfibril angle and crystallinity of bamboo treated with γ rays were tested by X-ray diffraction (XRD). The result indicated that crystallinity in bamboo increased when irradiation dose was less than 100 kGy, while the irradiation dose was raised to about 100 kGy, crystallinity in bamboo reduced. But during the whole irradiation process, the influence on microfibril angle was not obvious, so it was not the dominant factors on variation in physical-mechanical properties of bamboo during the process of irradiation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1717 (2011)
Energy Response of Tb3+-Doped Silicate Scintillating Glass to Hard X-Ray
GAO Qing-chun, GU Mu, HUANG Shi-ming, LIU Bo, NI Chen, and LIU Xiao-lin
Tb3+-doped silicate scintillating glass was made by high temperature melt-quenching method and the energy response to hard X-ray (from 5 to 80 keV) was measured. The response of photocurrent of silicate scintillating glass to X-ray (with various energy) is nonlinear. It was noted that the change in nonlinearity around Tb3+-doped silicate scintillating glass was made by high temperature melt-quenching method and the energy response to hard X-ray (from 5 to 80 keV) was measured. The response of photocurrent of silicate scintillating glass to X-ray (with various energy) is nonlinear. It was noted that the change in nonlinearity around 8 and 50 keV is obvious. This phenomenon is concerned with the production of abundant electrons when the scintillating glass absorbed X-ray and the energy response of scintillating glass to electrons..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1720 (2011)
Influence of Extended Light Source on Spectral Reconstruction in a Micro FTIR
FU Jian-guo, LIANG Zhong-zhu, and LIANG Jing-qiu
The influence of extended light source on spectral reconstruction in the FTIR (fourier transform infrared spectrometer) based on step mirrors was discussed in the present paper. The relationship between coherent intensity and solid angle was calculated. It was found that the coherent length became shorter and the spectThe influence of extended light source on spectral reconstruction in the FTIR (fourier transform infrared spectrometer) based on step mirrors was discussed in the present paper. The relationship between coherent intensity and solid angle was calculated. It was found that the coherent length became shorter and the spectrum resolving power became lower as a result of solid angle produced by the extended light source. The spectrum resolving power of system could reach the value as the theoretic design if the solid angle of extended light source is smaller than 0.001. The radiance will reduce if the size of extended light source is shortened. Therefore, a suitable size of extended light source can be chosen, considering the requirement of SNR in the optical design..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1723 (2011)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1 (2011)
Research Articles
The Evaluation of Uncertainty in the Results for Elements Rubidium, Strontium, Yttrium and Zirconium in Silicate Geological Samples by Polarized Energy Dispersive X-Ray Fluorescence Spectrometry
WANG Yi-ya, ZHAN Xiu-chun, YUAN Ji-hai, and FAN Xing-tao
A method for evaluation of uncertainty was established with standard deviation of relative error. Utilizing a polarized energy dispersive X ray fluorescence spectrometer(P-EDXRF)X-lab 2000 with pressed polyethylene-backed pellets, 76 national reference materials and 89 geological examination samples were analyzed, the A method for evaluation of uncertainty was established with standard deviation of relative error. Utilizing a polarized energy dispersive X ray fluorescence spectrometer(P-EDXRF)X-lab 2000 with pressed polyethylene-backed pellets, 76 national reference materials and 89 geological examination samples were analyzed, the results indicated that the relative errors consist with the normal distribution with confidence level 95%. The section standard deviations of relative errors acted as method global relative uncertainty and expanded factor was 2. The section relative uncertainty caused by precision was analyzed and relative uncertainty caused by accuracy based on the error transfer formula was isolated. The ratio of relative uncertainty caused by accuracy to the global relative uncertainty was different with different levels and elements. Two methods validated that the evaluation of global uncertainty is reasonable, with the first method being the formula of audited results in laboratory, and the second being the comparison of standard value with expanded uncertainty and a revised value with expanded uncertainty..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 6, 1707 (2011)
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