Journals >Spectroscopy and Spectral Analysis
Contents
2010
Volume: 30 Issue 4
64 Article(s)
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Research Article
Investigation on Spectrum of B2Σ+-X2Σ+and C2Πr-X2Σ+ Bands of AlO Radical in Shock Tube
PENG Zhi-min, YANG Qian-suo, LIU Chun, ZHU Nai-yi, and JIANG Zong-lin
There are some impurities such as aluminum dioxide adhering on the shock tube wall due to the ablating and heating of the aluminum diaphragm by high temperature gas. Under high temperature, the collision of AlO radicals with the gaseous molecules leads to transition of the electronic states and production of strong radThere are some impurities such as aluminum dioxide adhering on the shock tube wall due to the ablating and heating of the aluminum diaphragm by high temperature gas. Under high temperature, the collision of AlO radicals with the gaseous molecules leads to transition of the electronic states and production of strong radiation, which disturb the analysis of radiation spectrum of heated gases in shock tube. In the authors’ experiments, the air in the test section with adhering aluminum dioxide was heated to some 4 000-7 000 K, the spectrum of AlO radical was obvious in the range of 460-530 nm, which corresponds to B 2Σ＋-X 2Σ＋(T00=20 689 cm-1 band. There were several band heads for this band, the interval of neighbor heads was some 2 nm, and all the band heads were with the shortest wavelength. The characteristics of B 2Σ＋-X 2Σ＋ band were explored in experiment and by theory. In addition, the spectrum of C 2Πr-X 2Σ+(T00=33 047 cm-1) band was also investigated. The corresponding strength was lower than that of B 2Σ+-X 2Σ+ band, and the wavelength range of this band was some 270-335 nm where the radiation of A 2Σ+-X 2Π (T00=32 682 cm-1) band of OH radical also existed. This occurrence of the two bands in the same wavelength range is disadvantageous for the spectrum analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 865 (2010)
Crystallography Orientation by Molecular Spectrum of Structural Hydroxide in Pyroxene Megacryst
WANG Rong, ZHANG Bao-min, ZHAO Shan-rong, and MENG Jie
Crystal can be crystallographically oriented by molecular spectrum with the change in band shift, band intensity, and band shape. The three groups of band shift of augite are different between vertical to c-axis and parallel to c-axis: the first peak value 3 629-3 633 red shifts to 3 601-3 616; the same as the second pCrystal can be crystallographically oriented by molecular spectrum with the change in band shift, band intensity, and band shape. The three groups of band shift of augite are different between vertical to c-axis and parallel to c-axis: the first peak value 3 629-3 633 red shifts to 3 601-3 616; the same as the second peak value 3 514-3 543; on the contrary, the third peak value 3 460-3 465 is blue shift. The intensity of the first band is equivalent in two directions, while the second and the third parallel to c-axis are much stronger than the vertical. The wave shape is not quite different. The intensity of the Raman spectra vertical to ｃ-axis is stronger than that parallel to ｃ-axis in general, while the band shift and the shape show little difference. It was indicated that the geological tectonic environment can be reflected by the spectra of structural hydroxide with different crystal directions..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 869 (2010)
Studies on Photoinduced Electron and Proton Transfer Reactions of Nucleic Acid and Aromatic Ketone
WANG Jin-ting, SUN Qian, GE Ai-min, PAN Yang, ZHANG Li-min, and YU Shu-qin
The transient absorption spectra of two aromatic ketones (benzophenone (BP), xanthone (XT)) and four nucleic acids (guanosine 5’-monophosphate (GMP), adenosine 5’-monophosphate (AMP), cytidine 5’-monophosphate (CMP), thymidine 5’-monophosphate (TMP)) were obtained in 1∶1 CH3CN/H2O solution by using time-resolved laser The transient absorption spectra of two aromatic ketones (benzophenone (BP), xanthone (XT)) and four nucleic acids (guanosine 5’-monophosphate (GMP), adenosine 5’-monophosphate (AMP), cytidine 5’-monophosphate (CMP), thymidine 5’-monophosphate (TMP)) were obtained in 1∶1 CH3CN/H2O solution by using time-resolved laser flash photolysis at 355 nm. From the changes of the transient absorption spectra the authors can conclude that photoinduced proton transfer following electron transfer from GMP and AMP to excited BP and XT occurs, which is in accordance with free energy change of the reactions. For CMP and TMP, electron transfer and proton transfer do not appear because no ketyl and anion radical are generated. In addition, the rate constants for electron transfer from GMP, AMP, CMP, and TMP to the excited BP and XT were determined. As can be seen, there is a good correlation between kq and the free energy changes (ΔG) of the electron transfer reaction..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 875 (2010)
Theoretical Study on Radial Resonance Coupling of Cylindrical Photoacoustic Cells
YUAN Chang-ying, LIU Xian-yong, MENG Gui, and ZHAO Liang
Photoacoustic detection of trace concentrations of gases is one of the most sensitive techniques of infrared absorption spectroscopy. High-sensitivity photoacoustic detectors apply an acoustic resonator for the amplification of the weak photoacoustic signal. If the modulation frequency coincides with one of the resonanPhotoacoustic detection of trace concentrations of gases is one of the most sensitive techniques of infrared absorption spectroscopy. High-sensitivity photoacoustic detectors apply an acoustic resonator for the amplification of the weak photoacoustic signal. If the modulation frequency coincides with one of the resonance frequencies of the chamber, a standing acoustic wave is excited and the system works as an acoustic amplifier. The amplification of the resonator relies on the acting mode, quality factor, nature of microphone, and the coupling between electromagnetic radiation and the stand wave resonance mode. With different incidence orientation of the modulated IR laser relative to acoustic chamber, the sound pressure magnitude of resonance mode varies. The influence of different laser incidence orientation on the coupling coefficients of radial resonance mode of cylindrical photoacoustic cells was investigated by both theoretical deduction and numerical computation method. It is concluded that the coupling coefficients have two zeros and two maximums when the laser incidence angle varies from 0 to π／2. When the incidence angle is 0 or tan-1(0.859 2×2R/L), the coupling coefficients are zeros and the radial resonance is invalid. When the incidence angle is tan-1(0.556 8×2R/L) or tan-1(2R/L), the coupling coefficients are the maximums and the radial resonance is the strongest. Here R is the radius and L the length of the cell. The results therein before give some theoretical guidelines for photoacoustic cell designing, optimizing, installing and adjusting, and for improvement of detection sensitivity in trace gas detectors through maximal excitement of radial modes in cylindrical acoustic cells..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 879 (2010)
Study on the Excitation Mechanism of Upconversion Red Emission from Er3+ under Square Wave Excitation
DONG Li-qiang, HUANG Shi-hua, WEN Hong-yu, FENG Ying, and DUAN Xiao-xia
The rise and decay curves of Er3+ 4F9/2 upconversion emission in oxyfluoride tellurite glass were measured under the excitation at 808 nm from a laser diode driven by square waves. The lifetime of the intermediate state could be determined via rise times. Then the accumulation process of the 4F9/2 population was confirThe rise and decay curves of Er3+ 4F9/2 upconversion emission in oxyfluoride tellurite glass were measured under the excitation at 808 nm from a laser diode driven by square waves. The lifetime of the intermediate state could be determined via rise times. Then the accumulation process of the 4F9/2 population was confirmed. The excitation mechanism of up-conversion red emission under 808 nm excitation was confirmed by the rate equations and analyzing the relationship between the time constants of the rise and decay processes and the intermediate state. Square wave excited upconversion emission may also be used for measuring lifetimes of infrared energy levels with a conventional photomultiplier tube..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 883 (2010)
Infrared Band Assignments and Structure of Even-Numbered 2-Alkyl-7,7,8,8-Tetracyanoquinodimethane in Cast Films——Two Components of the CH2 Scissoring Vibrations not Related to Crystal Field Splitting
WANG Hai-shui, YANG Yan-hua, and OZAKI Yukihiro
Infrared (IR) spectra were measured for 2-octyl-, 2-dodecyl-, and 2-octadecyl-7,7,8,8-tetracyanoquinodimethane (C8TCNQ, C12TCNQ and C18TCNQ) in cast films, and it was found that each spectrum shows two components for the CH2 scissoring band at 1 471 and 1 462 cm-1. Polarized IR measurements showed that the micro-crystaInfrared (IR) spectra were measured for 2-octyl-, 2-dodecyl-, and 2-octadecyl-7,7,8,8-tetracyanoquinodimethane (C8TCNQ, C12TCNQ and C18TCNQ) in cast films, and it was found that each spectrum shows two components for the CH2 scissoring band at 1 471 and 1 462 cm-1. Polarized IR measurements showed that the micro-crystallites in the cast films take a random orientation in the plane of the plate. The intensity ratio of the two bands at 1 471 and 1 462 cm-1 (I1 471/I1 462) decreases observably with the increase in the length of the alkyl chain. Moreover, the relative intensity of the 1 471 cm-1 CH2 band to a band at 1 529 cm-1 (CC stretching mode of the TCNQ chromophore ring) does not change significantly for the three kinds of CnTCNQ while the relative intensity of the 1 462 cm-1 CH2 band to the band at 1 529 cm-1 increases markedly with the length of the alkyl chain. The above variations of the CH2 scissoring doublet of CnTCNQ are quite different from those of long-chain fatty acids (stearic acid and lignoceric acid) where the splitting of the CH2 scissoring vibration occurs due to a crystal field splitting. Considering the crystal structure of C12TCNQ and the above spectral variations, the authors assign the two components of the CH2 scissoring bands at 1 462 and 1 471 cm-1 of the CnTCNQ cast films to the interdigitated and non-interdigitated parts of the alkyl chains, respectively. Furthermore, the conclusion that the length of the non-interdigitated part of the alkyl chain is almost unchanged in the three kinds of even-numbered CnTCNQ could also be reached..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 892 (2010)
FTIR and 2D-IR Spectroscopic Studies on Different Sources of Herbra Cistanche
XU Rong, SUN Su-qin, LIU You-gang, CHEN Jun, LIU Tong-ning, and CHEN Shi-lin
In the present paper, Fourier transform infrared spectroscopy (FTIR) associated with second derivative infrared spectroscopy and two-dimensional correlation spectroscopy (2D-IR) were used to analyze the 3 different sources of Hebra cistanche. The results showed that these IR spectra showed their different macro-fingerpIn the present paper, Fourier transform infrared spectroscopy (FTIR) associated with second derivative infrared spectroscopy and two-dimensional correlation spectroscopy (2D-IR) were used to analyze the 3 different sources of Hebra cistanche. The results showed that these IR spectra showed their different macro-fingerprint features: the charactersistic peaks of C. deserticola were located at ~1 730, 1 633, 1 156, 1 081, 1 025 and 931 cm-1 and those of C. tubulosa were at 1 692, 1 631, 1 604, 1 516, 1 265 and 1 023 cm-1, respectively. The only two peaks at ~1 151 and 1 085 cm-1 of C. salsa were different from that of C. deserticola. As a result, the IR spectrum of C. deserticola could be identified obviously from that of the C. tubulosa, whose similar index was only 0.623 3, but it was very similar to that of C. salsa, whose similar index was up to 0.904 8, demonstrating very similar ingredients. However, the difference between C. deserticola and C. salsa was obvious in the second derivative IR spectra: the shape of the two peaks of C. deserticola at ~1 730 and 816 cm-1 were much sharper. In addition, the fingerprint characters in 2D-IR spectra were more visualized. The three kinds of herbs were quite different from each other in the number and intensity of autopeaks. Therefore, FTIR macro-fingerprint method can identify different sources of Hebra cistance fast, nondestructively and effectively.C. deserticola; C. tubulosa; C. salsa; Identification.
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 897 (2010)
Study of Near Infrared Spectral Preprocessing and Wavelength Selection Methods for Endometrial Cancer Tissue
ZHAO Li-ting, XIANG Yu-hong, DAI Yin-mei, and ZHANG Zhuo-yong
Near infrared spectroscopy was applied to measure the tissue slice of endometrial tissues for collecting the spectra. A total of 154 spectra were obtained from 154 samples. The number of normal, hyperplasia, and malignant samples was 36, 60, and 58, respectively. Original near infrared spectra are composed of many variNear infrared spectroscopy was applied to measure the tissue slice of endometrial tissues for collecting the spectra. A total of 154 spectra were obtained from 154 samples. The number of normal, hyperplasia, and malignant samples was 36, 60, and 58, respectively. Original near infrared spectra are composed of many variables, for example, interference information including instrument errors and physical effects such as particle size and light scatter. In order to reduce these influences, original spectra data should be performed with different spectral preprocessing methods to compress variables and extract useful information. So the methods of spectral preprocessing and wavelength selection have played an important role in near infrared spectroscopy technique. In the present paper the raw spectra were processed using various preprocessing methods including first derivative, multiplication scatter correction, Savitzky-Golay first derivative algorithm, standard normal variate, smoothing, and moving-window median. Standard deviation was used to select the optimal spectral region of 4 000-6 000 cm-1. Then principal component analysis was used for classification. Principal component analysis results showed that three types of samples could be discriminated completely and the accuracy almost achieved 100%. This study demonstrated that near infrared spectroscopy technology and chemometrics method could be a fast, efficient, and novel means to diagnose cancer. The proposed methods would be a promising and significant diagnosis technique of early stage cancer..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 901 (2010)
Study on the Determination of Total Nitrogen(TN) in Different Types of Soil by Near-Infrared Spectroscopy (NIS)
ZHANG Xue-lian, LI Xiao-na, WU Ju-ying, ZHENG Wei, HUANG Qian, and TANG Cong-feng
In the present paper, the feasibility of determination of total nitrogen (TN) content in different types of soil based on NIS technology was studied. Some surface and subsurface soil samples were collected from Jiangsu, Henan, Shanxi, Hebei and Jilin province in China, on behalf of paddy, calcareous, loess, coastal allIn the present paper, the feasibility of determination of total nitrogen (TN) content in different types of soil based on NIS technology was studied. Some surface and subsurface soil samples were collected from Jiangsu, Henan, Shanxi, Hebei and Jilin province in China, on behalf of paddy, calcareous, loess, coastal alluvial and black soil types separately. After being air-dried, milled and screened, the scanned spectra were obtained by near-infrared spectrometer using the sample with diameter below 1 millimeter, meantime the content of TN was measured with the traditional Kelvin method. A model between TN content and spectrum was established and also it was modified through some spectrum pretreatment using the OPUS software. Then a best model was chosen with root mean squares of crosscheck (RMSECV) being the lowest. Finally the stability and application of the model was discussed through quantitative analysis. The results showed that a good model can be separately established in each province using the surface soil from the same area on behalf of the same soil type, whose RMSECV were within 0.01% on average, and the correlation efficient was above 0.85 basically. The model established using the surface soil can be well used for analysis of TN content in other surface and subsurface soil from the same area whose TN was within the range of the model. The root mean squares of prediction (RMSEP) and correlation efficient of the quantitative analysis were at about 0.01% and 0.80 separately. However, maybe affected by soil types, the model established in one area had certain limitations in the application to other areas even as its TN content was within the range of the model. Whenas, choosing some data from each area randomly to form a new sample group can establish a good new integrated model with RMSECV and correlation efficient being 0.010 2% and 0.985 6 respectively and that can be well used to predict TN content in soil from each area..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 906 (2010)
A Study of Boletus Bicolor from Different Areas Using Fourier Transform Infrared Spectrometry
ZHOU Zai-jin, LIU Gang, and REN Xian-pei
It is hard to differentiate the same species of wild growing mushrooms from different areas by macromorphological features. In this paper, Fourier transform infrared (FTIR) spectroscopy combined with principal component analysis was used to identify 58 samples of boletus bicolor from five different areas. Based on the It is hard to differentiate the same species of wild growing mushrooms from different areas by macromorphological features. In this paper, Fourier transform infrared (FTIR) spectroscopy combined with principal component analysis was used to identify 58 samples of boletus bicolor from five different areas. Based on the fingerprint infrared spectrum of boletus bicolor samples, principal component analysis was conducted on 58 boletus bicolor spectra in the range of 1 350-750 cm-1 using the statistical software SPSS 13.0. According to the result, the accumulated contributing ratio of the first three principal components accounts for 88.87％. They included almost all the information of samples. The two-dimensional projection plot using first and second principal component is a satisfactory clustering effect for the classification and discrimination of boletus bicolor. All boletus bicolor samples were divided into five groups with a classification accuracy of 98.3％. The study demonstrated that wild growing boletus bicolor at species level from different areas can be identified by FTIR spectra combined with principal components analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 911 (2010)
Study on Variable Selection of NIR Spectral Information Based on GA and SCMWPLS
CAO Nan-ning, WANG Jia-hua, LI Peng-fei, and HAN Dong-hai
Spectral data compression and informative variable selection are the research focus on the application of NIR, which enable to simplify the model and improve the accuracy of prediction. The research used the pretreatment methods such as the second derivative, normalization and orthogonal signal correction (OSC) to filtSpectral data compression and informative variable selection are the research focus on the application of NIR, which enable to simplify the model and improve the accuracy of prediction. The research used the pretreatment methods such as the second derivative, normalization and orthogonal signal correction (OSC) to filter irrelevant array according to the concentration of soluble solid content (SSC) based on the Vis/NIR spectroscopy of apricot. SCMWPLS was used to select 880, 894-910 and 932 nm as the regions for constructing prediction PLS model with correlation coefficient (R) of 0.920, standard error of calibration (SEC) of 0.454 and standard error of prediction (SEP) of 0.470 for SSC. Besides, after conducting an independent run for 100 times, GA obtained the regression variables as 888 and 900 nm according to the higher frequency of selection to set up GA.MLR prediction model, and the R, SEC and SEP were 0.905, 0.488 and 0.459 respectively. The results of the two modeling methods are both better than those of full-region PLS model. This demonstrates that OSC enables to filter irrelevant signal array according to the concentration of SSC and reduce the latent variables used for modeling. Also, SCMWPLS and GA can identify the optimal combination of information variables. These methods have a universal significance on building NIR express analysis model with low dimension and high precision..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 915 (2010)
Analysis of Liquor Flavor Spectra and Pattern Recognition Computation
JIANG An, PENG Jiang-tao, PENG Si-long, WEI Ji-ping, and LI Chang-wen
Chinese liquor is a complex mixture and contains a large amount of microconstituents, which affects the quality and flavor of liquor. In order to discriminate liquor flavors rapidly, the spectra of liquors were obtained by FTIR and employed as the input patterns of pattern classification algorithms, then liquor flavor Chinese liquor is a complex mixture and contains a large amount of microconstituents, which affects the quality and flavor of liquor. In order to discriminate liquor flavors rapidly, the spectra of liquors were obtained by FTIR and employed as the input patterns of pattern classification algorithms, then liquor flavor discrimination models were built. This paper introduces liquor flavor pattern recognition algorithms comprehensively and systematically for the first time, and the algorithms contain statistical classifications (linear discriminant function, quadratic discriminant function, regularized discriminant analysis, and K nearest neighbor), prototype learning algorithm (learning vector quantization), support vector machine and adaboost algorithm. Experimental results show that the liquor flavor classification algorithms demonstrate good performance and achieve high accuracy, recognition rate and rejection rate..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 920 (2010)
Fast Discrimination of Varieties of Transgene Wheat Based on Biomimetic Pattern Recognition and Near Infrared Spectra
ZHAI Ya-feng, SU Qian, WU Wen-jin, HE Zhen-tian, ZHANG Zong-ying, AN Jia-shuang, DONG Jin, DENG Xin, HAN Cheng-gui, YU Jia-lin, LI Da-wei, CHEN Xiu-lan, and AN Dong
A new method for the fast discrimination of varieties of transgene wheat by means of near infrared spectroscopy and biomimetic pattern recognition (BPR) was proposed and the recognition models of seven varieties of transgene wheat and two varieties of acceptor wheat were built. The experiment adopted 225 samples, whichA new method for the fast discrimination of varieties of transgene wheat by means of near infrared spectroscopy and biomimetic pattern recognition (BPR) was proposed and the recognition models of seven varieties of transgene wheat and two varieties of acceptor wheat were built. The experiment adopted 225 samples, which were acquired from nine varieties of wheat. Firstly, a field spectroradiometer was used for collecting spectra in the wave number range from 4 000 to 12 000 cm-1. Secondly, the original spectral data were pretreated in order to eliminate noise and improve the efficiency of models. Thirdly, principal component analysis (PCA) was used to compress spectral data into several variables, and the cumulate reliabilities of the first ten components were more than 97.28%. Finally, the recognition models were established based on BPR. For the every 25 samples in each variety, 15 samples were randomly selected as the training set. The remaining 10 samples of the same variety were used as the first testing set, and all the 200 samples of the other varieties were used as the second testing set. As the 96.7% samples in the second set were correctly rejected, the average correct recognition rate of first testing set was 94.3%. The experimental results demonstrated that the recognition models were effective and efficient. In short, it is feasible to discriminate varieties of transgene wheat based on near infrared spectroscopy and BPR..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 924 (2010)
Identification of Egg Freshness Using Near Infrared Spectroscopy and One Class Support Vector Machine Algorithm
LIN Hao, ZHAO Jie-wen, CHEN Quan-sheng, CAI Jian-rong, and ZHOU Ping
Near infrared (NIR) spectroscopy combined with pattern recognition was attempted to discriminate the freshness of eggs. The algorithm of one-class support vector machine (OC-SVM) was employed to solve the classification problem due to imbalanced number of training samples. In this work, 86 samples of eggs (71 samples oNear infrared (NIR) spectroscopy combined with pattern recognition was attempted to discriminate the freshness of eggs. The algorithm of one-class support vector machine (OC-SVM) was employed to solve the classification problem due to imbalanced number of training samples. In this work, 86 samples of eggs (71 samples of fresh eggs and 15 samples of unfresh eggs) were surveyed by Fourier transform NIR spectroscopy. Firstly, original spectra of eggs in the wave-number range of 10 000-4 000 cm-1 were acquired. And then, principal component analysis (PCA) was employed to extract useful information from original spectral data, and the number of PCs was optimized. Finally, OC-SVM was performed to calibrate discrimination model, and the optimal PCs were used as the input eigenvectors of model. In order to obtain a good performance, the regularization parameter v and parameter σ of the kernel function in OC-SVM model were optimized in building model. The optimal OC-SVM model was obtained with ν=0.5 and σ2=20.3. Experimental result shows that OC-SVM got better performance than conventional two-class SVM model under the same condition. The OC-SVM model was achieved with identification rates of 80 for both fresh eggs and unfresh eggs in the independent prediction set. The identification rates of fresh eggs were 100% in two-class SVM model. However, when the two-class SVM model was used to discriminate the unfresh eggs of, the identification rates were 0% in the independent prediction set. Compared with conventional two-class SVM model, the OC-SVM model showed its superior performance in discrimination of minority unfresh eggs samples. This work shows that it is feasible to identify egg freshness using NIR spectroscopy, and OC-SVM is an excellent choice in solving the problem of imbalanced number of samples in training set..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 929 (2010)
Quality Analysis of Olive Oil and Quantification Detection of Adulteration in Olive Oil by Near-Infrared Spectrometry and Chemometrics
ZHUANG Xiao-li, XIANG Yu-hong, QIANG Hong, ZHANG Zhuo-yong, ZOU Ming-qiang, and ZHANG Xiao-fang
Discriminant analysis was used to classify 20 olive oil samples based on their near-infrared (NIR) spectra. The samples were successfully classified into two categories which are consistent with extra virgin olive oil and ordinary olive oil defined in the products. The NIR spectra of olive-oil mixtures containing colzaDiscriminant analysis was used to classify 20 olive oil samples based on their near-infrared (NIR) spectra. The samples were successfully classified into two categories which are consistent with extra virgin olive oil and ordinary olive oil defined in the products. The NIR spectra of olive-oil mixtures containing colza oil, corn oil, peanut oil, camellia oil, sunflower oil, and poppy seed oil were collected, respectively. The volume percent of adulterants ranged from 0 to 100%. The best spectrum bands for analysis were selected before developing partial least-squares (PLS) calibration models. The relative errors of prediction ranged from －5.67% to 5.61%. Results showed that the method combined with chemometrics methods and near-infrared spectrometry is simple, fast and credible for qualitative and quantitative analyses of olive oil samples..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 933 (2010)
Origins Determination of Herba Abri cantoniensis and Herba Abri mollis with FTIR Combined with Fuzzy Cluster and Curve-Fitting
WANG Yi-bing, CHEN Zhi-cheng, WU Wei-hong, KONG De-xin, HUANG Rong-shao, LIU Jun-xian, and HUANG Shu-shi
The methods of fuzzy cluster and curve-fitting combined with FTIR were used to determine the origins of Herba Abri cantoniensis and Herba Abri mollis. The spectra of Herba Abri cantoniensis and Herba Abri mollis are similar, both with typical spectral shapes. The two spectra can be divided into 3 parts: the 1st is 3 50The methods of fuzzy cluster and curve-fitting combined with FTIR were used to determine the origins of Herba Abri cantoniensis and Herba Abri mollis. The spectra of Herba Abri cantoniensis and Herba Abri mollis are similar, both with typical spectral shapes. The two spectra can be divided into 3 parts: the 1st is 3 500-2 800 cm-1, containing stretching bands of —OH, N—H, and CH2; the 2nd is 1 800-800 cm-1, containing stretching bands of ester carbonyl group and indican C—O(H), vibrational bands of CC and benzene ring; The 3rd is 800-400 cm-1, containing skeletal vibration and scissoring vibration of molecular. The recorded FTIR spectral data were processed by 9-point-smoothing, 1st derivative, SNV and fuzzy cluster analysis sequentially. The fuzzy cluster analysis was carried out by similarity or dissimilarity matrix, and two matrices are computed with Manhattan and Euclidean distance. The results indicated that the optimization used Manhattan and dissimilarity matrix, and 5 origins of Herba Abri cantoniensis were perfectly discriminated, but 2 origins of Herba Abri mollis were mixed and identified from the other 3 origins. So the characterized bands at 1 034 cm-1 of the average 1-D spectra of Herba Abri cantoniensis and Herba Abri mollis were fitted combining 2nd derivative for further distinguishing their spectral characteristic. The results of curve-fitting showed that the bands of wild Herba Abri cantoniensis and the other origin ones were decomposed to 11 and 9 component bands respectively, but the bands of Shanglin and the other origins Herba Abri mollis were decomposed to 9 and 8 component bands dissimilarly, and the locations and normalized densities of these component bands were different. From this, together with the results of fuzzy cluster analysis, it is concluded that the combination of two methods may identify the origins of Herba Abri cantoniensis and Herba Abri mollis availably..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 937 (2010)
Differentiation of Rhododendron Based on the Infrared Spectra of Petals
LUO Bi-rong, LIU Gang, ZHANG Yu-bin, ZHOU Xiang-ping, and SANG Lin
Several techniques were used to identify and classify plants. Mid-infrared spectroscopy combined with appropriate software was used in an attempt to differentiate different subgenus from Rhododendron. Fourier transform infrared (FTIR) spectroscopy was used for obtaining vibrational spectra of 46 petals from RhododendroSeveral techniques were used to identify and classify plants. Mid-infrared spectroscopy combined with appropriate software was used in an attempt to differentiate different subgenus from Rhododendron. Fourier transform infrared (FTIR) spectroscopy was used for obtaining vibrational spectra of 46 petals from Rhododendron. Very minor differences were observed in the FTIR spectra among four subgenuses. For the purpose of rapid differentiation, libraries of spectra were created using samples from each subgenus variety. Spectra of unknown samples were recorded and compared with those of the libraries and the rate of affinity (the match value) was measured automatically using the appropriate software (OMNIC). The results showed that petal samples from different subgenus varieties can be differentiated from each other. The study demonstrates that combining FTIR spectroscopy with appropriate analysis method can classify Rhododendron plants at subgenus level. It offers a potential method for the taxonomic research on plants system..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 943 (2010)
Successive Projections Algorithm and Its Application to Selecting the Wheat Near-Infrared Spectral Variables
CHENG Zhong, ZHANG Li-qing, LIU He-yang, and ZHU Ai-shi
Successive projections algorithm combined with partial least squares regression, termed as SPA-PLS approach, was implemented as a novel variable selection approach to multivariate calibration. The proposed approach was applied to near-infrared reflectance data for analyzing moisture in wheat. The number of variables seSuccessive projections algorithm combined with partial least squares regression, termed as SPA-PLS approach, was implemented as a novel variable selection approach to multivariate calibration. The proposed approach was applied to near-infrared reflectance data for analyzing moisture in wheat. The number of variables selected from 701 spectral variables was reduced to 16 by SPA, and the root mean squared error of prediction set (RMSEP) of the corresponding partial least squares regression models was decreased to 0.205 5% as well. The result indicates that the SPA-PLS approach by performing SPA prior to calibration not only can improve the model accuracy, but also decreases the number of spectral variables, so its resulting model becomes more concise. Moreover, as compared with genetic algorithm for wavelength selection, SPA is a deterministic search technique whose results are reproducible and it is more robust with respect to the choice of the validation set.Quantitative analysis; Wheat.
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 949 (2010)
In-Situ Research on Raman Spectroscopy of 1-Pentanol under High Pressure
TIAN Feng, and ZHENG Hai-fei
Raman spectra in 800-3 000 cm-1 of 1-pentanol were studied under high pressure and at ambient temperature (23 ℃) using a cubic zirconia anvil cell. The Raman peaks become sharper at higher pressure so that each individual C—H stretching mode is difficult to be distinguished. The Raman frequencies of the C—H stretching Raman spectra in 800-3 000 cm-1 of 1-pentanol were studied under high pressure and at ambient temperature (23 ℃) using a cubic zirconia anvil cell. The Raman peaks become sharper at higher pressure so that each individual C—H stretching mode is difficult to be distinguished. The Raman frequencies of the C—H stretching modes shift to a higher position with increasing pressures ranging between 0.1 MPa and 1.75 GPa. And the pressure induced frequency shifts are described by P(MPa)=69.652 65·(Δνp)single, T=23 ℃ +105.806 93 where 0＜(Δνp)single(cm-1)≤23 and P(MPa)=77.974 04·(Δνp)2 960, T=23 ℃+95.390 5 where 0<(Δνp)2 960(cm-1)≤21 and P(MPa)=126.956 39·(Δνp)2 863, T=23 ℃－110.648 09 where 0<(Δνp)2 863(cm-1)≤13, respectively. The global slope is (νsingle/P)T(14±1)cm-1·GPa-1, which can be used as a pressure sensor. Both the jumping of the frequencies and the figure under microscope indicate that the frozen pressure of the 1-pentanol at room temperature is 1.75 GPa. The molar volume change of the 1-pentanol is ΔVm=1.84×10－6 m3·mol-1 in the phase transformation from a liquid to a solid at 23 ℃..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 953 (2010)
Preparation of Silver Nanoparticles in Brnsted Acidic Ionic Liquid and Its Optical Properties
XU Cun-ying, LIU Ya-wei, HUA Yi-xin, and ZHANG Peng-xiang
The use of room-temperature ionic liquids (RTILs) as green media for preparation of nanomaterials is very attractive. Herein, anisotropic silver nanoparticles were synthesized via chemical reduction silver nitrate with sodium hypophosphite, employing brnsted acidic functionalized ionic liquid 1-butyl-3-methyl-imidazolThe use of room-temperature ionic liquids (RTILs) as green media for preparation of nanomaterials is very attractive. Herein, anisotropic silver nanoparticles were synthesized via chemical reduction silver nitrate with sodium hypophosphite, employing brnsted acidic functionalized ionic liquid 1-butyl-3-methyl-imidazolium dihydrogen phosphate (［bmim］H2PO4), which acted both as reaction medium and as a capping/shape-directing agent. The structure, morphology and optical absorption properties of anisotropic silver nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Visible (UV-Vis) absorption spectra. The XRD patterns revealed that the crystal was cubic structure for anisotropic silver nanoparticles. The SEM image indicated that the anisotropic silver nanoparticles were block-like with average lateral dimensions of about 30 nm, and they were self-assembled into two-dimensional disordered multilayer on the silicon wafer, and the particles appeared to be closely packed. The UV-Vis absorption spectrum exhibited a strong absorption peak around 438 nm and a weak peak at 353 nm, which came from dipole and quadrupole oscillation resonance, indicating the formation of non-spherical silver nanoparticles. The surface-enhanced Raman scattering (SERS) active of the anisotropic silver nanoparticles were investigated using trans-1,2-bis(4-pyridyl)-ethylene (BPE) as probe molecule. The results indicate that self-assembled silver film of anisotropic silver nanoparticles on the silicon wafer is excellent substrate for SERS measurements, demonstrating significant enhancement, trace detection capability, and good stability. The minimum analytic concentration was 10-9 mol·L-1 for trans-1,2-bis(4-pyridyl)-ethylene (BPE) molecules. It was also found that silver film stored for 90 days in air shows no significant degradation in its sensitivity..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 958 (2010)
Determination of Hydration Number of Methane Hydrates Using Micro-Laser Raman Spectroscopy
LIU Chang-ling, YE Yu-guang, and MENG Qing-guo
Methane hydrates are clathrate compounds that are formed by methane molecules and water molecules under low temperature and high pressure conditions. It was found that methane hydrates exist widely in sea-shelf floor and permafrost, and are considered as a potential energy resource. In the crystal lattice of clathrate Methane hydrates are clathrate compounds that are formed by methane molecules and water molecules under low temperature and high pressure conditions. It was found that methane hydrates exist widely in sea-shelf floor and permafrost, and are considered as a potential energy resource. In the crystal lattice of clathrate hydrate, the water molecules form both large cages (51262) and small cages (512) under the interaction of the hydrogen-hydrogen bond. In this paper, the authors designed a set of experimental apparatus for methane hydrates formation. Based on this equipment, the authors synthesized a series of methane hydrates in various systems in laboratory, including SDS solution (3% Wt) and methane, powdered ice and methane, and powdered ice and methane and natural sand with various sizes (i. e. 250-350, 180-250, 125-180 and 63-90 μm), under different temperature and pressure. The authors also designed a small device which was proved to be convenient for Raman determination of the methane hydrates. Raman spectroscopy was used to analyze the methane hydrates and to measure the structural parameters such as hydration numbers and cage occupancies. The results show that the methane hydrate samples are all in structure Ⅰ type, and hydration numbers and cage occupancies are almost independent of the sediment sizes. In the three systems, the large cages of methane hydrate samples are nearly full occupied, with the occupancy ratios larger than 97%, whereas the small cages between 80% and 86%. The hydration numbers of these methane hydrate samples are between 6.05 and 6.15..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 963 (2010)
SERS Spectra of L-Carnosine under the Interaction of Coordination with Adsorbed SnCl2
WANG Ming-hua, CHU You-ping, ZHENG Ju-fang, and LI Ze-lin
The authors have found that by virtue of utilizing the interaction of strongly chemically adsorbed SnCl2 with the analytes of organic/biologic molecules, the authors can not only effectively eliminate the laser carbonization and oxidation of probe molecules (e.g. pyridine), but also obtain specially enhanced Raman signThe authors have found that by virtue of utilizing the interaction of strongly chemically adsorbed SnCl2 with the analytes of organic/biologic molecules, the authors can not only effectively eliminate the laser carbonization and oxidation of probe molecules (e.g. pyridine), but also obtain specially enhanced Raman signals (e.g. vitamin B6). This method is applicable to the SERS spectroscopic analysis of highly reactive organic/biologic molecules. In the present paper, the authors report the investigation results on the electrochemical SERS spectra of L-carnosine (LCar) for the first time, mainly concentrating on the influence of adsorbed SnCl2 and applied potential on the SERS spectra of LCar. The SERS spectra of LCar were badly interfered by laser carbonization in the absence of SnCl2. However, in the presence of SnCl2 high quality SERS spectra of LCar could be obtained free of carbonization. It is demonstrated that LCar can be immobilized on the gold substrate indirectly via surface coordination with the pre-adsorbed SnCl2 under potential control. Apparently, such a sandwich-like adsorption configuration as Au-Sn(Ⅱ)-LCar is beneficial both to sensing the strong electromagnetic field at the nanostructured gold surface and to preventing the LCar from damage by the laser..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 967 (2010)
Normalization Methods for Ethanol Raman Spectra Quantitative Analysis
WU Zheng-jie, HUANG Yao-xiong, WANG Cheng, and LI Shao-fa
By performing different Raman normalization methods for ethanol quantitative analysis, the authors proposed the method which used the highest band intensity of the ethanol Raman spectra in the maximum concentration as the normalization metric for ethanol concentration quantitative analysis. By using this method, the coBy performing different Raman normalization methods for ethanol quantitative analysis, the authors proposed the method which used the highest band intensity of the ethanol Raman spectra in the maximum concentration as the normalization metric for ethanol concentration quantitative analysis. By using this method, the correlation coefficient was 0.999, the mean relative error was only 0.067 8, and the relative standard deviation (RSD) of the data from different experimental groups was 0.046 3. Both the validity and accuracy of this method were much better than the internal standard and ratio methods. Combined with baseline correction, the method can not only effectively resist the data fluctuation between different experimental groups, but also improve the accuracy of ethanol quantitative analysis obviously. The test using the method to measure the ethanol concentration of some wines from market proved that the relative standard deviations were all smaller than 0.012, indicating that the method is excellent for ethanol concentration quantitative analysis in commercial applications.
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 971 (2010)
Application of Raman Spectra Feature Extraction in Chemical Fiber Component Qualitative Identification
QIAO Xi-ya, DAI Lian-kui, and WU Jian-jian
According to the characteristics of the textile fibers Raman spectra, a qualitative identification method based on Raman feature extraction is proposed. This fast method consists of spectrum measurement and spectral data processing algorithm, including spectrum preprocessing, feature extraction and matching recognitionAccording to the characteristics of the textile fibers Raman spectra, a qualitative identification method based on Raman feature extraction is proposed. This fast method consists of spectrum measurement and spectral data processing algorithm, including spectrum preprocessing, feature extraction and matching recognition. It can be used to identify the components of fibers or fabrics, especially chemical fibers, which is an inspective difficulty in daily analytic work for its remarkable Raman feature. The authors performed an experiment to analyze 4 typical and widely used kinds of fibers as algorithm verification. They are terylene fiber, acrylic fiber, nylon fiber and rayon fiber. To identify the components of one test sample, first the authors set up feature tables of these 4 standard samples, which describe the features of their preprocessed spectra containing both position information and intensity information, then extract features of the test sample. The authors match these features with the tables and calculate the matching confidence coefficients of the results, which can be used to filter the unexpected matching results caused by accident and attain the final qualitative identification result. The experimental results confirm that this method is effective, efficient and expansible, which means it can be used to identify more actual fiber types by adding more standard spectra to the feature table database. In addition, it is a pure optical method, which needs only a small quantity of sample without any pretreatment. The whole identification process is damage-free, pollution-free and suitable for various kinds of fabrics. Compared to all existing methods, this Raman spectrum identification method can solve the limitation of efficiency, pollution, universality, and fill a gap in fabric inspection field..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 975 (2010)
Hydrocarbon Group Analysis of Gasoline by Raman Spectroscopy with Outlier Detection
DAN Tu-nan, and DAI Lian-kui
Hydrocarbon group of gasoline not only determines the quality of gasoline, but also directly relates to the impact of exhaust air on the environment. The present paper successfully applied Raman spectroscopy to the quantitative analysis of hydrocarbon group in gasoline. Contaminated samples were removed from calibratioHydrocarbon group of gasoline not only determines the quality of gasoline, but also directly relates to the impact of exhaust air on the environment. The present paper successfully applied Raman spectroscopy to the quantitative analysis of hydrocarbon group in gasoline. Contaminated samples were removed from calibration set by outlier detection, which effectively improved the partial least squares (PLS) prediction accuracy. The standard prediction errors of aromatics, olefin and oxygen content are 0.23, 0.52 and 0.143 respectively, and the corresponding multiple correlation coefficients of prediction (R2) are 0.987, 0.927 and 0.971. Experimental results show that the effectiveness of Raman spectroscopy for hydrocarbon group analysis in gasoline, and that the prediction accuracy is much better than near infrared spectroscopy or multidimensional gas chromatography. Quantitative calibrations based on Raman spectroscopy can also be used in the on-line analysis of gasoline production processes..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 979 (2010)
Rapid Determination of Hypoglycemic Tablets by Handheld Raman Spectrometer and KPCA-Clustering Analysis
WENG Xin-xin, ZHANG Zhong-hu, YIN Li-hui, and LU Feng
In the present paper, five different kinds of hypoglycemic tablets were identified using kernel principal component analysis (KPCA)-clustering analysis of their Raman spectra. KPCA was used to compress thousands of spectral data into several variables and to describe the body of the spectra before clustering analysis wIn the present paper, five different kinds of hypoglycemic tablets were identified using kernel principal component analysis (KPCA)-clustering analysis of their Raman spectra. KPCA was used to compress thousands of spectral data into several variables and to describe the body of the spectra before clustering analysis was chosen as further research method. The results showed that hypoglycemic tablets could be quickly classified using KPCA-clustering analysis. A disadvantage of Raman spectroscopy for this type of analysis is that it is primarily a surface technique. As a consequence, the spectra of the tablet core and its coating might differ. However, the KPCA-clustering analysis turned out to be a sufficiently reliable discrimination, i.e., 96% of the hypoglycemic tablets with coating and 100% of the hypoglycemic tablets without coating were predicted correctly. Overall, the Raman spectroscopic method in the present paper plays a good role in the identification and offers a new approach to the rapid discrimination of different kinds of hypoglycemic tablets.
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 984 (2010)
Comparative Analysis of Alfalfa Seeds between Space Flight Mutation and Its Control by Raman Spectroscopy
REN Wei-bo, ZHANG Yun-wei, DENG Bo, XU Zhu, and CHEN Li-bo
To realize the effect of space flight factors on chemical component of alfalfa seeds and its possible mechanism, seeds were loaded onto satellite “Jianbing No.1” in 2006 for 14 days’ space flight and then analyzed by Raman spectroscopy. Results showed that the intensity of two peaks (358 and 553 cm-1) of space flight sTo realize the effect of space flight factors on chemical component of alfalfa seeds and its possible mechanism, seeds were loaded onto satellite “Jianbing No.1” in 2006 for 14 days’ space flight and then analyzed by Raman spectroscopy. Results showed that the intensity of two peaks (358 and 553 cm-1) of space flight seeds had been increased and the intensity of four peaks (814, 1 122, 1 531 and 1 743 cm-1) of space flight seeds had been decreased compared with its ground control. Based on the classification of Raman spectra, the increased peaks of 358 and 553 cm-1 are related to DNA and Ca2+ respectively, which mean that the content of DNA and Ca2+ of alfalfa seeds had increased after space flight. The decreased peaks of 814, 1 122 and 1 743 cm-1 are related to saccharide and fatty acid respectively, which mean that the content of reserve energy of alfalfa seeds had decreased after space flight. These findings can be explained as follows: (1) The increase in the content of DNA may be explained by the DNA damage induced by space flight factors and DNA syntheses and duplication before the cell division. (2) The increase in the content of Ca2+ may be stimulated by the complexity of gravity during the space flight, especially the hypergravity. Recent researches in Abrabidopsis thaliana have provided additional proof. (3) The decrease of the energy materials such as saccharide and fatty acid may be explained by the consumption both during the repair process of DNA damage induced by cosmic radiation and during the germination of seeds because the dormancy of alfalfa seeds had been broken up by space flight factors (cosmic radiation, microgravity, vibration or others) which subsequently resulted in that nutritious materials of alfalfa seeds were used earlier than its ground control..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 988 (2010)
Effects of O3-FACE(Ozone-Free Air Control Enrichment) on Gas Exchange and Chlorophyll Fluorescence of Rice Leaf
LIANG Jing, ZENG Qing, ZHU Jian-guo, ZHU Chun-wu, CAO Ji-ling, XIE Zu-bin, LIU Gang, and TANG Hao-ye
O3-FACE (Ozone-free air control enrichment) platform has been established for observing the effect of elevated tropospheric ozone concentration on the gas exchange and chlorophyll fluorescence of two rice varieties (Wuyunjing 21 and Liangyoupeijiu). The results showed that high ozone concentration decreased the net phoO3-FACE (Ozone-free air control enrichment) platform has been established for observing the effect of elevated tropospheric ozone concentration on the gas exchange and chlorophyll fluorescence of two rice varieties (Wuyunjing 21 and Liangyoupeijiu). The results showed that high ozone concentration decreased the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) of rice leaves. After 76d fumigation the decline in them for Wuyunjing 21 was as follows: 21.7%, 26.64% and 24.74% respectively, and that for Liangyoupeijiu was as follows: 25.53%, 30.31% and 25.48% respectively; however, no significant impact on leaf intercellular CO2 concentration was observed. Chlorophyll fluorescence kinetics parameters changed as can be seen by the decrease in F0 (initial fluorescence in the dark), ETR (The apparent electron transfer rate) and ΦPSⅡ (actual photochemical efficiency of PSⅡ in the light), and the increase in NPQ (non-photochemical quenching). After 76 days of O3 treatment, the NPQ of Wuyunjing 21 and Liangyoupeijiu was enhanced by 16.37% and 11.77%, respectively. The impact of ozone on rice was a cumulative effect, and the extent of variation in the above parameters and the differences between the two varieties were enlarged as the O3 treatment time increased; At the same time because the rice leaf intercellular CO2 concentration did not significantly reduce, the inferred decrease in net photosynthetic rate was restricted by non-stomatal factors. The results of this experiment indicated that Liangyoupeijiu was more susceptible to ozone than Wuyunjing 21..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 991 (2010)
Water Quality Analysis by Three-Dimensional Fluorescence Spectra Based on Selective Model Combination
WU Xiao-li, LI Yan-jun, and WU Tie-jun
A selective model combination method is proposed in this paper to improve the precision of water quality analysis with three dimensional fluorescence spectra. A correlation coefficient criterion was designed to select effective excitation wavelengths for sub-models building, based on which the ridge regression method wA selective model combination method is proposed in this paper to improve the precision of water quality analysis with three dimensional fluorescence spectra. A correlation coefficient criterion was designed to select effective excitation wavelengths for sub-models building, based on which the ridge regression method was adopted to combine the selected sub-models to get the stacked model. Thirty two samples from surface water and urban wastewater were used as research objects with total organic carbon (TOC) index from 3.41 to 125.35 mg·L-1, and chemical oxygen demand (COD) index from 22.80 to 330.60 mg·L-1, and 10 excitation wavelengths in the range of 220-400 nm were adopted to generate three dimensional fluorescence spectra. Following the proposed correlation coefficient criterion, the excitation wavelengths of 260, 280 and 400 nm, and the excitation wavelengths of 220, 280 and 400 nm were selected respectively for TOC analysis and COD analysis, based on which two stacked models were built by using partial least square regression method for sub-models building and ridge regression method for sub-models combination. The experimental results show that, compared with the sub-models with the best prediction precision, the root mean square errors of prediction (RMSEP) of the stacked models decreased by 15.4% for TOC analysis, and 17.5% for COD analysis; and compared with the models without sub-models selection, the RMSEP of the stacked models decreased by 6.1% for TOC analysis and 10.9% for COD analysis.
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 996 (2010)
Electrical and Optical Phase Transition Properties of Nano Vanadium Dioxide Thin Films
LIANG Ji-ran, HU Ming, WANG Xiao-dong, LI Gui-ke, KAN Qiang, JI An, YANG Fu-hua, LIU Jian, WU Nan-jian, and CHEN Hong-da
Nano-vanadium dioxide thin films were prepared through thermal annealing vanadium oxide thin films deposited by dual ion beam sputtering. The nano-vanadium dioxide thin films changed its state from semiconductor phase to metal phase through heating by homemade system. Four point probe method and Fourier transform infraNano-vanadium dioxide thin films were prepared through thermal annealing vanadium oxide thin films deposited by dual ion beam sputtering. The nano-vanadium dioxide thin films changed its state from semiconductor phase to metal phase through heating by homemade system. Four point probe method and Fourier transform infrared spectrum technology were employed to measure and anaylze the electrical and optical semiconductor-to-metal phase transition properties of nano-vanadium dioxide thin films, respectively. The results show that there is an obvious discrepancy between the semiconductor-to-metal phase transition properties of electrical and optical phase transition. The nano-vanadium dioxide thin films’ phase transiton temperature defined by electrical phase transiton property is 63 ℃, higher than that defined by optical phase transiton property at 5 μm, 60 ℃; and the temperature width of electrical phase transition duration is also wider than that of optical phase transiton duration. The semiconductor-to-metal phase transiton temperature defined by optical properties increases with increasing wavelength in the region of infrared wave band, and the occuring temperature of phase transiton from semiconductor to metal also increases with wavelength increasing, but the duration temperature width of transition decreases with wavelength increasing. The phase transition properties of nano-vanadium dioxide thin film has obvious relationship with wavelength in infrared wave band.The phase transition properties can be tuned through wavelength in infrared wave band, and the semiconductor-to-metal phase transition properties of nano vanadiium dioxide thin films can be better characterized by electrical property..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1002 (2010)
Health State Evaluation of Power-Shift Steering Transmission Using PCA-AHP Methodology Based on Spectrometric Oil Analysis
ZHANG Ying-feng, MA Biao, ZHENG Chang-song, ZHANG Jin-le, and FAN Yu-heng
Spectrometric oil analysis is an important method to study the running state of power-shift steering transmission (PSST). An evaluation model of PSST health state was developed on the basis of the theories of principal component analysis (PCA) and analytic hierarchy process (AHP) using spectrometric oil analysis data. Spectrometric oil analysis is an important method to study the running state of power-shift steering transmission (PSST). An evaluation model of PSST health state was developed on the basis of the theories of principal component analysis (PCA) and analytic hierarchy process (AHP) using spectrometric oil analysis data. Considering the concept of mechanical equipment and wear elements in spectrometric oil analysis data, the health value was employed to quantitatively describe the running state degree of PSST, and the grades of health state were classified based on the health values. The oil analysis data were studied during the process of choosing principal components. The weight vectors of principal components were obtained by using the AHP method. In the course, the conformation of judgement matrix and the consistency check were also studied. The evaluation model was developed by combining the PCA and AHP methods. This model has been proved to have better accuracy in evaluating the running state of PSST. This work is important for developing state evaluation of PSST..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1008 (2010)
Stability Analysis of On-Board Calibration System of Spatially Modulated Imaging Fourier Transform Spectrometer
GAO Jing, JI Zhong-ying, WANG Zhong-hou, and CUI Yan
Spatially modulated imaging Fourier transform spectrometer (SMIFTS) was an instrument that depended on interference, and after calibration, the reconstruction spectrum can quantificationally reflect the diffuse reflection of target under sunshine. On-board calibration of SMIFTS confirmed the change of SMIFTS according Spatially modulated imaging Fourier transform spectrometer (SMIFTS) was an instrument that depended on interference, and after calibration, the reconstruction spectrum can quantificationally reflect the diffuse reflection of target under sunshine. On-board calibration of SMIFTS confirmed the change of SMIFTS according to relative spectrum calibration, inspected long-time attenuation of SMIFTS optical system, and corrected export data of SMIFTS. According to the requirement of remote sensor application, it must stay in vacuum environment for a long time. As a radiant standard, the stability of lamp-house in long time is the most important characteristic of on-board calibration system. By calculation and experimentation, analyses of on-board calibration of SMIFTS, and testing spaceflight environment characteristic of on-board calibration, the difficulty in the key parts of on-board calibration of SMIFTS such as lamp-house, spectrum filter and integrating sphere was solved. According to the radiation-time stability testing for lamp-house and optics, particle-radiation testing, environmental-mechanics testing and hot vacuum examination, good result was obtained. By whole-aperture and part-field comparative wavelength calibration, the spectrum curve and before-launch interferogram were obtained. After comparison with reconstruction spectrum under different condition, the stability and credibility of SMIFTS on-board calibration system was proved..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1013 (2010)
Study on Spectrum of Oil Film in Ice-Infested Waters
LI Ying, LIU Bing-xin, LAN Guo-xin, MA Long, and GAO Chao
Oil spills in ice-infested waters are a subject of great concern to corporations, local residents, and government agencies, which participate in oil exploration, production, and transportation in ice-infested regions recently. For developing a credible and effective response to oil spill in ice-infested waters, a fieldOil spills in ice-infested waters are a subject of great concern to corporations, local residents, and government agencies, which participate in oil exploration, production, and transportation in ice-infested regions recently. For developing a credible and effective response to oil spill in ice-infested waters, a field experiment was performed on the spectrum of oil film in ice-infested waters. In this experiment, four groups of spectrum samples were collected, including clean sea water, brash ice and even ice and sea water /brash ice /even ice contaminated by diesel and crude oil. The experiment results indicated that: the same sort of oil with different background had different reflectance at the same wavelength, and so did the same sort of oil with the same background but different distribution state; nevertheless there were some common characteristics within the same oil. For example, diesel had two apparent characteristics, no matter on the surface of sea water or brash ice or even ice, the first of which was that the reflectance curves of diesel film were first lower and then higher than that of clean sea water, brash ice or even ice according to the wavelength; the second was that the reflectance curves of diesel film were almost equaled to that of the background between 400 and 510 nm in sea water, 410 and 510 nm in brash ice and 490 and 510 nm in even ice. The spectrum curves of crude oil had a representative sphenoid reflectance-peak which appeared between 750 and 770 nm. These characteristics of oil film in terms of ice and oil type could be effectively used to distinct the oil with sea water and sea ice, meanwhile this experiment would improve and facilitate the detecting and monitoring proposal of oil which had been spilled in moving, broken pack ice and fast-ice environment in the ocean..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1018 (2010)
Investigation on Multiband Attenuation Compatibility of Carbon Nanotubes
XIAO Ting, YANG He-lin, ZHANG Guo-ping, LEI Li-wen, and ZENG Fan-qing
The present investigation was focused on how to realize the attenuating compatibility of the electromagnetic defilade material in UV-Vis-Infrared band. Optical spectra of CNTs was investigated on the basis of analytical technologies such as Fourier transform infrared spectroscopy, UV-Vis spectrophotometer, laser scatteThe present investigation was focused on how to realize the attenuating compatibility of the electromagnetic defilade material in UV-Vis-Infrared band. Optical spectra of CNTs was investigated on the basis of analytical technologies such as Fourier transform infrared spectroscopy, UV-Vis spectrophotometer, laser scattering, and electron microscopy. It was demonstrated that the multi-band attenuation characteristic of CNTs is effectively associated with additives, concentrations and configurations. The measured sample with a concentration of 0.04 g·L-1, in which the radius of CNTs was 30-50 nm, bore the maximum value of the extinction coefficient of 7.825 m2·g-1 at the point of 265 nm. Meanwhile, this kind of CNTs presents outstanding unified attenuation properties in infrared wave band. when the thickness of the CNTs film is 0.1 mm and the total mass of CNTs is 0.349 mg in optical path. Especially, the unified attenuation goes beyond 90% in 4.0-6.25 and 7.0-16.7 μm..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1022 (2010)
Cucurbit［8］urils-Induced Room Temperature Phosphorescence of Phenanthrene and Fluorene
GAO Zhong-wei, MU Lan, XUE Sai-feng, TAO Zhu, and ZENG Xi
In this paper, a new room temperature phosphorescence for phenanthrene and fluorene were first reported with cucurbit［8］uril as the revulsant, KI as the heavy atomperturber, and Na2SO3 as deoxygenation. The RTP maximum wavelengths were λex/λem=282/509 nm and λex/λem=276/518 nm and the RTP lifetimes of the two systems wIn this paper, a new room temperature phosphorescence for phenanthrene and fluorene were first reported with cucurbit［8］uril as the revulsant, KI as the heavy atomperturber, and Na2SO3 as deoxygenation. The RTP maximum wavelengths were λex/λem=282/509 nm and λex/λem=276/518 nm and the RTP lifetimes of the two systems were 1.82 and 3.68 ms respectively. Under optimum experimental conditions, the RTP intensity was liner with phenanthrene and fluorene concentration in the range of 1.0×10－7-1.5×10－6 mol·L-1, 1.5×10－6-1.0×10－5 mol·L-1 and 8.0×10－7-8.0×10－6 mol·L-1, respectively. The detection limits were 4.8×10－9 mol·L-1 and 8.0×10－9 mol·L-1 respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1026 (2010)
Study on Online Self-Calibration Technique for Trace Gas Analyzer Based on Tunable Diode Laser Absorption Spectroscopy
ZHANG Jun, ZHU Yong, CHEN Jun-qing, and LIANG Bo
After decades of development, the tunable diode laser absorption spectroscopy (TDLAS) became one of the most promising techniques for online trace gas analyzing in process industry. Limited by its principle, the measurement result of TDLAS system is seriously affected by temperature and gas pressure variation. For thisAfter decades of development, the tunable diode laser absorption spectroscopy (TDLAS) became one of the most promising techniques for online trace gas analyzing in process industry. Limited by its principle, the measurement result of TDLAS system is seriously affected by temperature and gas pressure variation. For this reason, most TDLAS systems employed temperature and pressure sensors, which can provide information for partly correcting the error. Theoretically, the gas absorption theory itself is not perfect enough to give an analytical relation between the measurement error and the temperature & pressure variation. Practically, temperature and pressure sensors are not available in some harsh working condition. To address these problems, an online self-calibration technique with a reference gas cell is proposed to compensate temperature and pressure variation induced measurement error in a TDLAS system. More specifically, a reference gas cell filled with known proportion target gas is placed on site, surrounded by working gas to be measured. The main body of the gas cell is made from a stainless tube, one end is a silica glass window and the other end is a reflector. A pressure bellows is connected to the middle of the stainless tube by a branch conduit. The pressure bellows can adaptively deform to keep the pressure balance between the inside and outside gas. Thereby, the temperature and pressure inside the reference cell are equal to that of the gas outside. To ensure the similarity between the reference gas cell and working gas cell, they share the same laser diode source and signal processing circuit. In one working cycle, the TDLAS system obtains the absorption spectrum of both gas cells synchronously. Then the concentration of the trace gas can be easily obtained by calculating the absorption intensity proportion of both absorption spectra without considering the affection of temperature and pressure. The principle, design, and experiments of this technique were presented in this paper..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1030 (2010)
Studies on the Ultraviolet Light Induced Absorption Change in Nearly Stoichiometric LiNbO3∶Fe∶Mn Crystals
LI Xiao-chun, WANG Li-zhong, and LIU Hong-de
The ultraviolet light induced absorption change (UV-LIA) of nearly stoichiometric LiNbO3∶Fe∶Mn crystals was investigated. The experimental results show that the UV-LIA coefficient change of LiNbO3∶Fe∶Mn crystal is not large for congruent sample, increases with increasing Li2O concentration, reaches the maximum 4.2 cm-1The ultraviolet light induced absorption change (UV-LIA) of nearly stoichiometric LiNbO3∶Fe∶Mn crystals was investigated. The experimental results show that the UV-LIA coefficient change of LiNbO3∶Fe∶Mn crystal is not large for congruent sample, increases with increasing Li2O concentration, reaches the maximum 4.2 cm-1 at about 49.57 mol% Li2O, and then decreases with further increasing Li2O content. Because the UV-LIA change has a direct relationship with the nonvolatile holographic sensitivity, the experimental results indicate that the nearly stoichiometric LiNbO3∶Fe∶Mn crystal with 49.57 mol% Li2O is the appropriate candidate material for the nonvolatile holographic storage. The visible light induced bleaching results also prove that the suitable composition is 49.57 mol%. With the increase in Li2O concentration in the LiNbO3∶Fe∶Mn crystal, the amount of the bipolaron increases. Bipolarons may be dissociated either optically or thermally so that metastable small polarons are formed. The energy level for biopolaron and small polaron is at about 2.5 and 1.6 eV respectively. When the Li2O concentration continues to increase, the small polarons are dominating intrinsic defects. The bipolarons have stronger photorefractive capability than the small polarons. The amount of bipolaron is the most with 49.57 mol% Li2O concentration in the LiNbO3∶Fe∶Mn crystal. Based on these experimental results, a three-photorefractive-centers model in nearly stoichimetric LiNbO3∶Fe∶Mn crystal is suggested: besides Fe2+/Fe3+ and Mn2+/Mn3+, bipolarons/small polarons are considered as the third photoactive center..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1035 (2010)
Study on the Synchronous Interactions between Different Thiol-Capped CdTe Quantum Dots and BSA
MA Jin-jie, LIANG Jian-gong, and HAN He-you
The modifier of quantum dots plays an important role in synthesis and nature of quantum dots, however the effect on the interaction between quantum dots and protein is not very clear until up to now. In the present paper, the interactions of CdTe quantum dots with bovine serum album (BSA) were studied by spectroscopy mThe modifier of quantum dots plays an important role in synthesis and nature of quantum dots, however the effect on the interaction between quantum dots and protein is not very clear until up to now. In the present paper, the interactions of CdTe quantum dots with bovine serum album (BSA) were studied by spectroscopy methods including ultraviolet-visible absorption spectrometry (UV-Vis), fluorescence spectrometry (FL) and infrared spectrometry (IR). The CdTe quantum dots were modified by three different thiol-complex including thioglycolic acid, L-cysteine and glutathione, i.e. thioglycolic acid capped CdTe quantum dots (CdTeT), L-cysteine capped CdTe quantum dots (CdTeL) and glutathione capped CdTe quantum dots (CdTeG) respectively. The quenching constant KSV and corresponding thermodynamic parameters, such as enthalpy change (ΔHθ), entropy change (ΔSθ), Gibbs free energy change (ΔGθ), were calculated according to Stern-Volmer equations. The results showed that CdTeT, CdTeL and CdTeG all have a strong ability of quenching the fluorescence of bovine serum albumin, and the interactions of the three types of thiol-capped CdTe quantum dots with BSA were static quenching process. The quenching constant of KSV (TGA) is similar to KSV (GSH), which is much less than KSV (L-Cys). The binding forces of CdTeT and CdTeL with the BSA were the main contributions from hydrophobic force according to the thermodynamic parameters (ΔHθ>0, ΔSθ>0 and ΔGθ<0), while the binding forces of CdTeG with BSA were composed of both hydrogen bonding force and hydrophobic force according to the thermodynamic parameters(ΔHθ<0, ΔSθ>0 and ΔGθ<0). It was found that different functional group and molecular volume size of thiol surface modified reagent played an important role in the interactions between CdTe QDs and BSA..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1039 (2010)
MAP Based Super-Resolution Method for Hyperspectral Imagery
WANG Li-guo, and ZHAO Yan
Hyperspectral imagery (HSI) is used in more and more fields, but its low spatial resolution limits its applications severely. The super-resolution algorithm catches more and more eyes but has not been solved well. In this case, the present paper aimed to do the following researches. The relation modeling was constructeHyperspectral imagery (HSI) is used in more and more fields, but its low spatial resolution limits its applications severely. The super-resolution algorithm catches more and more eyes but has not been solved well. In this case, the present paper aimed to do the following researches. The relation modeling was constructed between observed HSI of low resolution and target HSI of high resolution. In the modeling, space transformation was implemented by introducing the operator related to endmembers (EMs) of interest. Maximum posterior probability (MAP) algorithm was used to realize the super-resolution (SR) recovery. Experiments show that the proposed SR method has good recovery effect, low computational complexity, robust noise resistance, and can preserve classes of interest..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1044 (2010)
Study on Synchronous Correlation between Fruit Characteristic Spectrum and the Parameter of Internal Quality for Hamlin Sweet Orange Fruit
DENG Lie, HE Shao-lan, YI Shi-lai, ZHENG Yong-qiang, XIE Rang-jin, ZHANG Xuan, and MAO Sha-sha
The purpose of our study is to study the relationship between the reflective spectrum of fruit and the internal quality of the orange fruit and find the suitable mark spectrum that can synchronously measure the several fruit quality index at same time to lay a foundation for the development of a rapid and nondestructivThe purpose of our study is to study the relationship between the reflective spectrum of fruit and the internal quality of the orange fruit and find the suitable mark spectrum that can synchronously measure the several fruit quality index at same time to lay a foundation for the development of a rapid and nondestructive field fruit quality analysis technique by analyzing the visible-near infrared spectrum. Mature Hamlin orange (Citrus sinensis(L)cv. Hamlin sweet orange) fruits were individually mensurated for their reflective spectrum by using FieldSpec-HH spectrometer and for their contents of total soluble solid (TSS), citric acid and vitamin C (Vc) by chemistry analysis. The experiment results showed that the fruit reflectivity values (x) at 988 nm was significantly correlated to both TSS (y)(r＝0.387** , y＝13.957x+5.405), TSS/acid ratio(y)(r＝0.440**, y＝75.120x+37.256), and Vc(r＝0.309*). Both of TSS and Vc contends were positively correlated with the second derivatives of the reflective spectrum at 943 nm, with correlation coefficients of 0.339* and 0.355**. TSS/acid ratio was positively correlated only with the reciprocal log values of the reflective spectrum at 944 nm(r＝0.304*).The results in this study indicated that fruit quality indexes TSS, Vc and TSS/acid can be synchronously, rapidly and nondestructively field measured at the same time by the 988 or 429 nm reflective spectrum test and special regress equation operation..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1049 (2010)
Study of Spectral Properties of J-Aggregates of Mixed Cyanine Dyes
MENG Tao, KANG Ling-hua, XU Duan-fu, WANG Du-jin, LI Xiao-wei, and ZOU Jing
The J-aggregates and the photosensitive properties of two kinds of mixed cyanine dye and the corresponding independent cyanine dyes absorbed on AgBr cubic microcrystal were investigated. The reflection spectra of the J-aggregates of the mixed cyanine dyes and the corresponding independent cyanine dyes were measured by The J-aggregates and the photosensitive properties of two kinds of mixed cyanine dye and the corresponding independent cyanine dyes absorbed on AgBr cubic microcrystal were investigated. The reflection spectra of the J-aggregates of the mixed cyanine dyes and the corresponding independent cyanine dyes were measured by the use of UV-Vis spectroscopy. The results showed that the absorption band of the mixed J-aggregates absorbed on AgBr cubic microcrystal had two-peak wavelengths and accorded with the independent cyanine dyes, respectively. The sensitive performance of the mixed cyanine dyes was much enhanced compared to the corresponding cyanine dyes..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1053 (2010)
Nano TiO2 Modification of Bamboo and Its Antibacterial and Mildew Resistance Performance
SUN Feng-bo, YU Yan, JIANG Ze-hui, REN Hai-qing, WANG Ge, and LIU Xing-e
Bamboo, a kind of forest resources only less important than wood, is especially easy to mildew during outdoor service. In this work, TiO2 sols were synthesized under low-temperature condition by sol-gel method. The crystalline TiO2 film with a diameter of approximate 40-90 nm was used to coat bamboo at low temperature.Bamboo, a kind of forest resources only less important than wood, is especially easy to mildew during outdoor service. In this work, TiO2 sols were synthesized under low-temperature condition by sol-gel method. The crystalline TiO2 film with a diameter of approximate 40-90 nm was used to coat bamboo at low temperature. The TiO2 films were characterized by nuclear magnetic resonance spectrometer (NMR), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The effects of temperature on film crystal forms, its antibacterial, and mildew resistance properties were mainly investigated. The results showed that the modified bamboo in low temperature solution (20, 60 and 105 ℃) was mainly covered with anatase nano TiO2 film. The nano-TiO2-modified bamboo maintained the natural wood color, texture and structure, and improved its anti-bacterial property from non-anti-bacterial to anti-escherichia coli, and the bactericidal rate reached over 99%. Meanwhile its mildew resistance property increased over 10 times. So this method is expected to become the new way of functional improvement on bamboo, and has the reference meaning for the protection and improvement of wood and other biologic materials..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1056 (2010)
Detecting Fire Smoke Based on the Multispectral Image
WEI Ying-zhuo, ZHANG Shao-wu, and LIU Yan-wei
Smoke detection is very important for preventing forest-fire in the fire early process. Because the traditional technologies based on video and image processing are easily affected by the background dynamic information, three limitations exist in these technologies, i.e. lower anti-interference ability, higher false deSmoke detection is very important for preventing forest-fire in the fire early process. Because the traditional technologies based on video and image processing are easily affected by the background dynamic information, three limitations exist in these technologies, i.e. lower anti-interference ability, higher false detection rate and the fire smoke and water fog being not easily distinguished. A novel detection method for detecting smoke based on the multispectral image was proposed in the present paper. Using the multispectral digital imaging technique, the multispectral image series of fire smoke and water fog were obtained in the band scope of 400 to 720 nm, and the images were divided into bins. The Euclidian distance among the bins was taken as a measurement for showing the difference of spectrogram. After obtaining the spectral feature vectors of dynamic region, the regions of fire smoke and water fog were extracted according to the spectrogram feature difference between target and background. The indoor and outdoor experiments show that the smoke detection method based on multispectral image can be applied to the smoke detection, which can effectively distinguish the fire smoke and water fog. Combined with video image processing method, the multispectral image detection method can also be applied to the forest fire surveillance, reducing the false alarm rate in forest fire detection..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1061 (2010)
Spectrofluorimetric Study of Supramolecular Inclusion between Rodenticide Brodifacoum and β-Cyclodextrin and Application
DUAN Yun-qing, DUAN Zhi-qing, MIN Shun-geng, XIONG Yan-mei, DUAN Jia, YE Sheng-feng, and WANG Dong
The supramolecular interaction between β-cyclodextrin and brodifacoum, an anticoagulant rodenticide of the second generation, was studied by spectroscopy. The results showed that brodifacoum and β-cyclodextrin could form an inclusion complex with an association constant of 1.048×104 L·mol-1 and a 1∶1 stoichioThe supramolecular interaction between β-cyclodextrin and brodifacoum, an anticoagulant rodenticide of the second generation, was studied by spectroscopy. The results showed that brodifacoum and β-cyclodextrin could form an inclusion complex with an association constant of 1.048×104 L·mol-1 and a 1∶1 stoichiometry based on Benesi-Hildebrand equation. The inclusion mechanism was proposed to explain the inclusion mode. It was indicated that the hydrophobic group of brodifacoum molecule, biphenyl, entered into the cavity of β-cyclodextrin. At the same time, it was also observed the significant enhancement of fluorescence of brodifacoum after forming inclusion complex. According to the fluorescence enhancement phenomenon, a spectrofluorimetric method of detecting brodifacoum in aqueous media was established with the linear range of 8.0×10-8-4.0×10-6 mol·L-1 and the correlation coefficient of 0.999 4. The detection limit of the method was 8.8×10-9 mol·L-1. The proposed method was successfully applied to determine the trace amount of brodifacoum in environment water and the recovery was in the range of 87.3% to 103.9%..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1065 (2010)
Retrieval of Leaf Water Content of Winter Wheat from Canopy Hyperspectral Data Using Partial Least Square Regression
WANG Yuan-yuan, LI Gui-cai, ZHANG Li-jun, and FAN Jin-long
Accurate estimation of leaf water content (LWC) from remote sensing can assist in determining vegetation physiological status, and further has important implications for drought monitoring and fire risk evaluation. This paper focuses on retrieving LWC from canopy spectra of winter wheat measured with ASD FieldSpec Pro.Accurate estimation of leaf water content (LWC) from remote sensing can assist in determining vegetation physiological status, and further has important implications for drought monitoring and fire risk evaluation. This paper focuses on retrieving LWC from canopy spectra of winter wheat measured with ASD FieldSpec Pro. The experimental plots were treated with five levels of irrigation (0, 200, 300, 400 and 500 mm) in growing season, and each treatment had three replications. Canopy spectra and LWC were collected at three wheat growth stages (booting, flowering, and milking). The temporal variations of LWC, spectral reflectance, and their correlations were analyzed in detail. Partial least square regression embedded iterative feature-eliminating was designed and employed to obtain diagnostic bands and build prediction models for each stage. The results indicate that LWC decreases quickly along with the winter wheat growth. The mean values of LWC for the three stages are respectively 338.49%, 269.65%, and 230.90%. The spectral regions correlated strongly with LWC are 1 587-1 662 and 1 692-1 732 nm (booting), 617-687 and 1 447-1 467 nm (flowering), and 1 457-1 557 nm (milking). As far as the LWC prediction models are concerned, the optimum modes of spectral data are respectively logarithmic, 1st order derivative and plain reflectance. The diagnostic bands detected by PLS are from SWIR, NIR, and SWIR. Retrieval accuracy at the flowering stage is the highest (R2cv=0.889) due to the enhancement of leaf water information at canopy scale via multiple scattering. At the booting and milking stage, accuracies are relatively lower (R2cv=0.750, 0.696), because the retrieval of LWC is negatively affected by soil background and dry matter absorption respectively. This research demonstrated clearly that the spectral response and retrieval of LWC has distinct temporal characteristics, which should not be neglected when developing remote sensing product of crop water content in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1070 (2010)
Quantitative Remote Sensing Retrieval for Algae in Inland Waters
SONG Yu, SONG Xiao-dong, JIANG Hong, GUO Zhao-bing, and GUO Qing-hai
Chlorophyll is a very important indictor for the eutrophication status of lake water body. Using remotely sensed data to achieve real-time dynamic monitoring of the spatial distribution of chlorophyll has great importance. This paper aims to find the best band for the hyperspectral ratio model of chlorophyll-a, and takChlorophyll is a very important indictor for the eutrophication status of lake water body. Using remotely sensed data to achieve real-time dynamic monitoring of the spatial distribution of chlorophyll has great importance. This paper aims to find the best band for the hyperspectral ratio model of chlorophyll-a, and take advantage of this model to implement remote sensing retrieval of algae in Taihu Lake. By the analysis of the spectral reflectance and water quality sampling data of the surface water body, the regression model between the ratio of reflectance and chlorophyll-a was built, and it was showed that the ratio model between the wavelengths around 700 and 625 nm had a relatively high coefficient value of determination (R2), while the ratio model constructed with 710 nm and visible wavelengths showed a descended R2 following with the increment of the visible wavelengths. Combined with in-situ water samplings analysis and spectral reflectance measurement, the results showed that it’s possible to retrieve algae water body using the MODIS green index (GI). The spatial distributions of chlorophyll-a and algae in Taihu Lake were extracted successfully using MODIS data with the algorithm developed in this paper..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1075 (2010)
Monitoring of Cnaphalocrocis Medinalis Guenee Based on Canopy Reflectance
SUN Hong, LI Min-zan, ZHOU Zhi-yan, LIU Gang, and LUO Xi-wen
The canopy reflectance of rice was measured in the filed in order to monitor the damaged region caused by Cnaphalocrocis medinalis Guenee. The characteristics of canopy spectral reflectance were analyzed in contrast region and damaged regions. When rice plant was damaged by Cnaphalocrocis medinalis Guenee, the chlorophThe canopy reflectance of rice was measured in the filed in order to monitor the damaged region caused by Cnaphalocrocis medinalis Guenee. The characteristics of canopy spectral reflectance were analyzed in contrast region and damaged regions. When rice plant was damaged by Cnaphalocrocis medinalis Guenee, the chlorophyll absorption was decreased in the band of 600-700 nm. The canopy reflectance of moderate damage region was lower than that of the contrast region, while the reflectance of severe damage region rice was higher near 550 nm. The canopy reflectance of Cnaphalocrocis medinalis Guenee damaged rice was fluctuant and exhibited the significant peak in the NIR band of 750-770nm. Meanwhile, red edge inflection point as one of the most important spectral parameters was analyzed at different damage levels based on the first derivative of reflectance spectra. The analysis results indicated that red edge inflection position moved to direction of blue light (short wavelength) with the affection severity increasing. Then the modified reflectance of rice canopy was calculated based on zero-mean calculation and standard deviation. It was easy to find the degree of deviation from the average of samples and distinguish the damaged region from experiment plots. The canopy modified reflectance was gently in the contrast region, but changed violently in the affected regions in the band of 750-950 nm. The analysis of Cnaphalocrocis medinalis Guenee affected regions illustrated that the Cnaphalocrocis medinalis Guenee was increased with the increase in severity. The vegetation index was applied in detection of Cnaphalocrocis medinalis Guenee damaged regions because of the composition of multi-wavelength information. The wavelengths 762 and 774 nm were chosen to build detection parameters of Cnaphalocrocis medinalis Guenee such as NIR-RVI, NIR-DVI, NIR-NDVI and KI. The results indicated that the NIR-NDVI could be used to identify the damaged region with contrast region efficiently. The accurate rate of 25 verification samples selected randomly reached 70%. The preliminary studies on rice Cnaphalocrocis medinalis Guenee damaged regions provided a new method to detect the affected regions in the wide area..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1080 (2010)
Rapid Determination of Sugars in Hemicellulose Extraction Liquor by Dual-Wavelength Spectrophotometry
CHI Cong-cong, ZHANG Zeng, CHAI Xin-sheng, and GE Wei-wei
The traditional Douglas colorimetric method (phloroglucinol–glacial acetic acid colorimetry) could only be used to measure all forms of five-carbon sugars, including mono-, oligo- and poly- saccharides. Relative improvement is done on this method to achieve simultaneous deter mination of pentosan, hexosan and their monThe traditional Douglas colorimetric method (phloroglucinol–glacial acetic acid colorimetry) could only be used to measure all forms of five-carbon sugars, including mono-, oligo- and poly- saccharides. Relative improvement is done on this method to achieve simultaneous deter mination of pentosan, hexosan and their monosaccharides, by the dual-wavelength method. Results indicate that 425 nm is the equal molar absorption wavelength of pentose and hexose, while 553 nm is the maximum absorption wavelength of pentoses. So the calculating formula has been greatly simplified based on the absorbance at 425 and 553 nm. The research results of interfering substances in the extraction liquor show that the lignin and glucuronic acid has no significant influence on the deter mination of pentoses or hexoses. It is concluded that this improved method has high precision and accuracy, and its recovery range is from 97.4% to 101.9%. Therefore, as a simple and rapid method, it is quite appropriate for measuring mixed sugars of pentoses and hexoses in the extraction liquor from hardwood or gra minaceous plant..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1084 (2010)
A Review on Polarization Information in the Remote Sensing Detection
GONG Jie-qiong, ZHAN Hai-gang, and LIU Da-zhao
Polarization is one of the inherent characteristics. Because the surface of the target structure, internal structure, and the angle of incident light are different, the earth’s surface and any target in atmosphere under optical interaction process will have their own characteristic nature of polarization. Polarimetric Polarization is one of the inherent characteristics. Because the surface of the target structure, internal structure, and the angle of incident light are different, the earth’s surface and any target in atmosphere under optical interaction process will have their own characteristic nature of polarization. Polarimetric characteristics of radiation energy from the targets are used in polarization remote sensing detection as detective information. Polarization remote sensing detection can get the seven-dimensional information of targets in complicated backgrounds, detect well-resolved outline of targets and low-reflectance region of objectives, and resolve the problems of atmospheric detection and identification camouflage detection which the traditional remote sensing detection can not solve, having good foreground in applications. This paper introduces the development of polarization information in the remote sensing detection from the following four aspects. The rationale of polarization remote sensing detection is the base of polarization remote sensing detection, so it is firstly introduced. Secondly, the present researches on equipments that are used in polarization remote sensing detection are particularly and completely expatiated. Thirdly, the present exploration of theoretical simulation of polarization remote sensing detection is well detailed. Finally, the authors present the applications research home and abroad of the polarization remote sensing detection technique in the fields of remote sensing, atmospheric sounding, sea surface and underwater detection, biology and medical diagnosis, astronomical observation and military, summing up the current problems in polarization remote sensing detection. The development trend of polarization remote sensing detection technology in the future is pointed out in order to provide a reference for similar studies..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1088 (2010)
Speciation Analysis of Cadmium in Cadmium-Enriched Plants with SE-HPLC Combined with ICP-MS and ESI-MS
LI Bin, LIU Li, WANG Qiu-quan, YAN Hua, and HUANG Ben-li
Different species of ferns (pyrrosia lingua, Lepisorus thunbergianus, Lycopodium japonicum, Elaphoglossum yoshinagae and Woodwardia japonica) were cultivated using different species of cadmium as cultivation solution. The results showed that there were differences in enrichment amounts of cadmium in different parts of Different species of ferns (pyrrosia lingua, Lepisorus thunbergianus, Lycopodium japonicum, Elaphoglossum yoshinagae and Woodwardia japonica) were cultivated using different species of cadmium as cultivation solution. The results showed that there were differences in enrichment amounts of cadmium in different parts of plants (amounts in root＞in stem＞in leaves). And it was found that different species of cadmium could induce synthesization of plant-chelated peptides (PCs) with different extents. And then PCs was coordinated with cadmium to decrease the toxicity from cadmium. There are some kinds of peptides ligands found in plants, which are mainly PC3, iso-PC3(βAla) and iso-PC2(βAla). In the present paper, the distribution of cadmium in different parts of ferns was studied after the ferns were intimidated with different species of cadmium. And the species of PCs-Cd coordination compounds were also investigated to explain the detoxification mechanism aroused by it..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1096 (2010)
Classification of Licorice Based on Inorganic Elements Characteristics
ZHOU Ying-qun, YU Hua, LI Ying, SUN Su-qin, ZHAO Run-huai, and CHEN Shi-lin
The present study focused on the ecological characteristics of medicinal plants Glycyrrhiza uralensis from two typical ecological environments with two different growth patterns respectively. The authors detected the contents of 16 kinds of inorganic elements in 24 licorice samples with two different producing areas (iThe present study focused on the ecological characteristics of medicinal plants Glycyrrhiza uralensis from two typical ecological environments with two different growth patterns respectively. The authors detected the contents of 16 kinds of inorganic elements in 24 licorice samples with two different producing areas (i.e. Gansu and Inner-Mongolia) and growth patterns (i.e., wild species and the cultivated), using the methods of ICP-MS and ICP-AES after microwave-assisted digestion. With the systematic analytic methods, including the analysis of total element distribution, Q-type cluster analysis of the characteristic elements, and the comparison of element and the ratio of two elements among the samples one by one, the authors constructed the inorganic element fingerprint chromatogram of G. uralensis based on the contents of the 16 inorganic elements (K, Ca, Na, Mg, P, Ca, Cr, Mn, Fe, S, Ni, Cu, Zn, Sr, Mo and Sn). Based on the characteristic elements selected by principal component analysis, the result of Q-type cluster analysis showed consistency with the growth pattern of licorice. By comparing the differences of the inorganic elements in different samples, the authors discovered that the combination of elements Mo and Sr not only provides the bases for the growth pattern of licorice, but also can be used as a diagnostic criteria for the division of its producing area. This study also indicated that the content ratios of Na∶P and K∶Ca can also provide reliable references for the assessment of different production patterns. It gives insight into the differences in the inorganic element of licorice with different producing area and production pattern treatments. In conclusion, the method we founded here turned out to be intuitive, informative, and highly accurate, and can be used to reveal the characteristic of inoganic elements in medicinal plant..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1101 (2010)
Comparison of the Contents of Mineral Elements in the Roots of Four Germplasms Bupleurum L. Planted in Different Soils
CAO Hai-lu, WEI Jian-he, HE Chun-e, YANG Cheng-min, and YU Jing
Contents of 21 elements, including of K, Ca, Mg, Na, Fe, Mn, Cu, Zn, Ni, Ti, Cr, Mo, V, Zr, Co, Se, Sn, Cs, Cd, Hg, and Pb, in the roots of four germplasms Bupleurum L. planted in the soils from seven regions, were analyzed by ICP-MS/ICP-AES. The results showed that the contents of K, Ca, Mg and Na are mainly ascribed Contents of 21 elements, including of K, Ca, Mg, Na, Fe, Mn, Cu, Zn, Ni, Ti, Cr, Mo, V, Zr, Co, Se, Sn, Cs, Cd, Hg, and Pb, in the roots of four germplasms Bupleurum L. planted in the soils from seven regions, were analyzed by ICP-MS/ICP-AES. The results showed that the contents of K, Ca, Mg and Na are mainly ascribed to the effect of germplasms, and the contents of Fe, Cu, Ni, Ti, Cr, V, Zr, Se, Sn, Cs, Cd, Hg and Pb are mainly ascribed to the effect of soils considering the integrated effects of germplasms and soils. Generally, element contents in the root of G-GS were higher and that in the root of G-ZC were lower in the four germplasms of Bupleurum L. Element contents in the root of Bupleurum L. planted in S-HR were higher, while that planted in S-YQS were lower as a whole among these soils from seven regions. The difference in the element contents has an important effect on the research into the contents of officinal ingredients and their curative effect in the roots of four original Bupleurum L. germplasms planted in the soils from seven regions. And this study also provides an important scientific foundation for the choices of germplasms and soils in the cultivation of high-yield and high-quality Bupleurum L..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1105 (2010)
Determination of Nutrient Fungus Dietary Fiber and Structural Characterization
WANG Song-jun, CAO Lin, HOU Tian-ping, HOU Yue, and ZHANG Gui-ying
The simultaneous determination of trace elements in ultrafine agaric was carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES). The experiments were done using wet acid digestion sample preparation. The samples were dissolved at 120 ℃ constant temperature. The requirements of determination byThe simultaneous determination of trace elements in ultrafine agaric was carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES). The experiments were done using wet acid digestion sample preparation. The samples were dissolved at 120 ℃ constant temperature. The requirements of determination by ICP-AES can be satisfied at an acidity controlled less than 10%. The method is simple, rapid and economic. National standard material GBW07602 was detected by authentication. Its accuracy is between 1.12% and 6.15. The precision is between 0.41% and 5.69%. At thesame time, the surface structure of ultrafine agaric powder was examined by scanning electron microscope. And the dietary fiber was determined for fungus protein, crude fat, crude fiber, moisture and ash content by chemical analysis. The study on external and internal relevance of agaric could provide a new approach to scientific research on the development and application of fungus dietary fiber..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1109 (2010)
Study on Adsorption Behavior of Crosslinked Polyarylonitrile for Copper, Lead, Cadmium and Zinc Ions by Atomic Absorption Spectrometry
Shawket Abliz, PENG Yang, WANG Ji-de, and Ismayil Nurulla
The crosslinked polymer polyacrylonitrile was synthesized by suspension polymerization using acrylonitrile and divinylbenzene. It has been used as adsorbent of some toxic heavy metals in environmental waters. Its adsorption for metals and the factors which affect the adsorption capacity were studied by atomic absorptioThe crosslinked polymer polyacrylonitrile was synthesized by suspension polymerization using acrylonitrile and divinylbenzene. It has been used as adsorbent of some toxic heavy metals in environmental waters. Its adsorption for metals and the factors which affect the adsorption capacity were studied by atomic absorption spectrometry (AAS). The experimental results showed that under the optimal adsorption conditions, the pH of adsorbate solution was 5-6, static adsorption time was 1.5-2 h, and adsorption procedure was carried out at room temperature, polyacrylonitrile as adsorbent has high adsorption capacity (mg·g-1) for Cu2+, Pb2+, Cd2+ and Zn2+, which can reach 26.6, 45.2, 39.7 and 32.5 separately. Adsorption rate (%) was 83.6, 87.1, 85.3 and 86.7 respectively during the 1.5-2 h static adsorption time. It will be more than five-hour static adsorption time before adsorption rate reaches more than 96%. Using 0.10 mol·L-1 chloride acid as the best desorption solvent to desorb the adsorbates, the recovery of them reached 95%. At the same time the adsorption mechanism of polymer was studied..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1113 (2010)
Ferric Iron Absorption in ΔrpfFxoo, a Gene Deletion Mutant of Xanthomonas oryzae pv.Oryzae, Assayed Using Atomic Absorption Spectrophotometry
SUN Lei, WU Mao-sen, and HE Chen-yang
The ferric iron absorption is one of the most important limiting factors of bacterial growth of Xanthomonas oryzae pv. oryzae. It has been previously speculated that rpfFxoo might be involved in the ferric iron metabolism of the pathogen. In the present study, ΔrpfFxoo, a gene deletion mutant, was generated from the wiThe ferric iron absorption is one of the most important limiting factors of bacterial growth of Xanthomonas oryzae pv. oryzae. It has been previously speculated that rpfFxoo might be involved in the ferric iron metabolism of the pathogen. In the present study, ΔrpfFxoo, a gene deletion mutant, was generated from the wild-type strain PXO99A of Xoo through the homologous recombination, and Fe content was assayed using flame atomic absorption in PXO99A and ΔrpfFxoo. The results indicated that the recovery was 99.7% and the relative standard deviation was 1.89 under optimized AAS operating conditions. The increase in Fe absorption in PXO99A and ΔrpfFxoo was observed with the increasing time. However, the ferric content of ΔrpfFxoo was significantly lower than that of PXO99A (P<0.05). It is suggested that rpfFxoo is involved in iron metabolism in Xanthomonas oryzae pv. oryzae..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1117 (2010)
Analysis of Soluble Ca Content in Banana Pulp Based on Pretreatment of Digestion Model in Vitro
LI Ji-hua, HUANG Mao-fang, XU Fei, TANG Yong-fu, and FU Tiao-kun
In the present paper, soluble Ca content in banana pulp was analyzed with pretreatment of digestion model in vitro. All the samples were digested by strong acid (perchloric acid and nitric acid with 1∶4 ratio) and determined by AA700 flame atomic absorption spectrophotometry (FAAS). Meanwhile, the reproducibility of thIn the present paper, soluble Ca content in banana pulp was analyzed with pretreatment of digestion model in vitro. All the samples were digested by strong acid (perchloric acid and nitric acid with 1∶4 ratio) and determined by AA700 flame atomic absorption spectrophotometry (FAAS). Meanwhile, the reproducibility of the analytical method was investigated. The results showed that (1) Content of Ca was 1.479 mg·g-1·DW in eighty percent maturity banana pulp. And the relative standard deviation was 4.12%. (2) Contents of Ca in the soluble and insoluble fractions were 1.108 and 0.412 mg·g-1·DW, respectively in eighty percent maturity banana pulp with pretreatment of digestion model in vitro. The extraction rate was 74.9% and the residue rate was 27.8%. (3) The relative standard deviations of the analytical results of Ca contents in those two fractions were 2.56% and 9.10%, respectively, in the reproducibility tests. It was showed that the digestion model in vitro did not affect the reproduction quality significantly. Moreover, the deviation between the theoretical value and the summation value of the extraction and the residue rates was only 2.7%, which showed good availability of the digestion model in vitro to be used as a pretreatment method in mineral element analysis process. (4) Relative standard deviation and recovery yield in the determination procedure were 0.11%(n=9)and 99.2%, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1120 (2010)
Determination of Arsenic, Antimony, Mercury and Selenium in Different Parts of Acanthopanax Senticosus Harms by Atomic Fluorescence Spectrometry
LIU Chun-tao, HOU Hai-ge, FAN Nai-ying, and LI Han-hui
A method for the determination of arsenic, antimony, mercury and selenium in different parts (root, stem, leaf and fruit) of acanthopanax senticosus harms using hydride generation atomic fluorescence spectrometry with microwave digestion was developed. Under the optimized experimental conditions, the concentration of aA method for the determination of arsenic, antimony, mercury and selenium in different parts (root, stem, leaf and fruit) of acanthopanax senticosus harms using hydride generation atomic fluorescence spectrometry with microwave digestion was developed. Under the optimized experimental conditions, the concentration of arsenic, antimony, mercury and selenium showed a linear relationship with the fluorescence intensity. The detection limit of arsenic was 0.068 ng·mL-1, and the RSD was 1.05%. The detection limit of antimony was 0.155 ng·mL-1, and the RSD was 1.32%. The detection limit of mercury was 0.014 ng·mL-1, and the RSD was 2.03%. The detection limit of selenium was 0.052 ng·mL-1, and the RSD was 2.34%. The method was checked in terms of accuracy and precision using the standard reference substance of hair(GBW07601), and proved to be sensitive and rapid with satisfactory results. The content of arsenic, mercury and selenium is high in the leaf, and that of antimony is higher in the root than in other parts..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1123 (2010)
Determination of Nine Mineral Elements in Hulless Barley by Ultraviolet Spectrophotometry and Flame Atomic Absorption Spectrometry
LIU Jin, and ZHANG Huai-gang
The contents of nine mineral elements, including sulphur, zinc, calcium, magnesium, potassium, sodium, iron, copper and manganese in five hulless barley (Hordeum vulgare L. var. nudum Hook. f.) lines were determined by ultraviolet spectrophotometry and flames atomic absorption spectrometry (FAAS). For the determinationThe contents of nine mineral elements, including sulphur, zinc, calcium, magnesium, potassium, sodium, iron, copper and manganese in five hulless barley (Hordeum vulgare L. var. nudum Hook. f.) lines were determined by ultraviolet spectrophotometry and flames atomic absorption spectrometry (FAAS). For the determination of sulphur, the samples were dissolved by magnesia and anhydrous sodium carbonate at 250 ℃ for 0.5 h and at 550 ℃ for 3 h in the muffle furnace, and then a certain amount of barium chloride was put into the sample solution for colorimetry of the UV-Vs spectrophotometer. For the determination of other eight mineral elements, all of the samples were dissolved by a kind of incinerating method: first, the sample was put into the muffle furnace at 250 ℃ for 0.5 h and at 550 ℃ for 2.5 h, then two droplets of 50%HNO3 were distributed into each sample, and the last step was putting the sample into the muffle furnace at 550 ℃ for 0.5 h. And then all of the ash was dissolved by 50%HNO3 to 50 milliliter and determined by flames atomic absorption spectrometry. The precision, accuracy, repeatability and stability of the method were discussed too. The results showed that the relative standard deviations (RSD) were between 1.2% and 3.7%; The average recoveries were 97.44%-101.52% and the relative standard deviations (RSD) of sample determination were 1.3%-3.8%. The repeatability experiment showed that the relative standard deviations (RSD) were 2.6%-6.1%. And the content of each mineral element was the same after 24 hours; All these showed that the method has a good precision, accuracy, repeatability and stability. In all the hulless barley samples, the average contents were in the order of K＞S＞Mg＞Ca＞Fe＞Na＞Zn＞Mn＞Cu, and the contents of zinc, iron and manganese closely related to people’s health were relatively higher than other crops. The data of the experiment could provide an accurate and credible evidence for the deeper exploitation of the hulless barley..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1126 (2010)
Spectral Analysis of Pottery-Painting Pigments from the Monarch Bai Tomb of Zhongli State
YANG Yu-zhang, ZHANG Ju-zhong, ZUO Jian, KAN Xu-hang, and ZHOU Qun
Based on the analysis of Raman spectroscopy and XRD methods, the structures of different pigments on the painted pottery from the Monarch Bai Tomb of Zhongli State in the middle and late Spring and Autumn period at Shungdun Village, Bengbu City, Anhui Province were analyzed. The result shows that all the pigments, inclBased on the analysis of Raman spectroscopy and XRD methods, the structures of different pigments on the painted pottery from the Monarch Bai Tomb of Zhongli State in the middle and late Spring and Autumn period at Shungdun Village, Bengbu City, Anhui Province were analyzed. The result shows that all the pigments, including red, yellow and black pigments, have been well preserved, and these three pigments were identified as cinnabar, goethite and carbon black respectively. Both Raman spectroscopy and XRD analysis show that the crystal composition of red pigments, cinnabar, is very pure without quartz crystal, the associated crystal of natural cinnabar, and at the same time the crystal size of cinnabar is possibly at the nanometer scale. It suggests that this red pigments perhaps were a synthetic material or processed and purified by our ancestors. The discovery of goethite shows that this mineral has been used as pigments as early as in the Spring and Autumn period. This is the earliest example that goethite was used as yellow pigments..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1130 (2010)
Study of the Fourth Generation of Salvia Miltiorrhiza Bge by XRF
ZHU Yan-ying, GUO Xi-hua, WANG Zhi-zhou, and GUAN Ying
X-ray fluorescence spectrum(XRF)analytic method was used to analyze and compare the contents and varieties of mineral elements in the ground group Salvia miltiorrhiza Bge, and the fourth generation Salvia miltiorrhiza Bge with space flight mutagenesis breeding in order to provide important basic data for selecting highX-ray fluorescence spectrum(XRF)analytic method was used to analyze and compare the contents and varieties of mineral elements in the ground group Salvia miltiorrhiza Bge, and the fourth generation Salvia miltiorrhiza Bge with space flight mutagenesis breeding in order to provide important basic data for selecting high quality breed and further research. The result indicates that the varieties of the main mineral elements in the two samples are the same basically, but Cu/Zn ratio is enhanced to 1.0, the contents of microelements Cr, Mn and Fe increase by 0.6, 0.5, and 0.3 times respectively compared with the ground group. To conclude, in the space group the contents and proportions of the mineral elements are improved and optimized. X-ray fluorescence spectrum analytic method has many advantages, such as quickness, simplicity, high sensitivity, wide measure range, etc. The method can be used for quantitative element analysis and study of Chinese herbal medicines..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1134 (2010)
Study on Spectrum Analysis of X-Ray Based on Rotational Mass Effect in Special Relativity
YU Zhi-qiang, XIE Quan, and XIAO Qing-quan
Based on special relativity, the formation mechanism of characteristic X-ray has been studied, and the influence of rotational mass effect on X-ray spectrum has been given. A calculation formula of the X-ray wavelength based upon special relativity was derived. Error analysis was carried out systematically for the calcBased on special relativity, the formation mechanism of characteristic X-ray has been studied, and the influence of rotational mass effect on X-ray spectrum has been given. A calculation formula of the X-ray wavelength based upon special relativity was derived. Error analysis was carried out systematically for the calculation values of characteristic wavelength, and the rules of relative error were obtained. It is shown that the values of the calculation are very close to the experimental values, and the effect of rotational mass effect on the characteristic wavelength becomes more evident as the atomic number increases. The result of the study has some reference meaning for the spectrum analysis of characteristic X-ray in application..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1136 (2010)
Spectra and Thermal Analysis of the Arc in Activating Flux Plasma Arc Welding
CHAI Guo-ming, and ZHU Yi-feng
In activating flux plasma arc welding the welding arc was analyzed by spectra analysis technique, and the welding arc temperature field was measured by the infrared sensing and computer image technique. The distribution models of welding arc heat flow density of activating flux PAW welding were developed. The compositiIn activating flux plasma arc welding the welding arc was analyzed by spectra analysis technique, and the welding arc temperature field was measured by the infrared sensing and computer image technique. The distribution models of welding arc heat flow density of activating flux PAW welding were developed. The composition of welding arc affected by activated flux was studied, and the welding arc temperature field was studied. The results show that the spectral lines of argon atom and ionized argon atom of primary ionization are the main spectra lines of the conventional plasma welding arc. The spectra lines of weld metal are inappreciable in the spectra lines of the conventional plasma welding arc. The gas particle is the main in the conventional plasma welding arc. The conventional plasma welding arc is gas welding arc. The spectra lines of argon atom and ionized argon atom of primary ionization are intensified in the activating flux plasma welding arc, and the spectra lines of Ti, Cr and Fe elements are found in the activating flux plasma welding arc. The welding arc temperature distribution in activating flux plasma arc welding is compact, the outline of the welding arc temperature field is narrow, the range of the welding arc temperature distribution is concentrated, the welding arc radial temperature gradient is large, and the welding arc radial temperature gradient shows normal Gauss distribution..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1141 (2010)
Development of a Portable SOM Detector Based on NIR Diffuse Reflection
LI Min-zan, PAN Luan, ZHENG Li-hua, and AN Xiao-fei
A portable soil organic matter detector based on near infrared diffuse reflectance was developed. The detector uses a microprocessor 89S52 as the micro controller unit (MCU) and consists of an optical system and a control system. The optical system includes an 850 nm near-infrared LED lamp-house, a lamp-house driving-cA portable soil organic matter detector based on near infrared diffuse reflectance was developed. The detector uses a microprocessor 89S52 as the micro controller unit (MCU) and consists of an optical system and a control system. The optical system includes an 850 nm near-infrared LED lamp-house, a lamp-house driving-circuit, a Y type optical fiber, a probe, and a photoelectric sensor. The control system includes an amplifying circuit, an A/D circuit, a display circuit with LCD, and a storage circuit with USB interface. Firstly the single waveband optical signal from the near-infrared LED is transferred to the surface of the target soil via the incidence fibers. Then the reflected optical signal is collected and transferred to the photoelectric sensor, where the optical signal is converted to the electrical signal. Subsequently, the obtained electrical signal is processed by 89S52 MCU. Finally, the calculated soil organic matter content is displayed on the LCD and stored in the USB disk. The calibration experiments using the estimation model of the soil organic matter were conducted. Thirteen kinds of natural soil samples were prepared, each divided into five sub-samples. After measurement, the natural samples were dried under the condition of 105 ℃ for 24 h, and then the same measurements were performed. The analysis of the correlation between the detected SOM content and the measured reflectance was carried out. For the natural soil samples, R2=0.907, while R2 reached 0.963 for the dried soil samples. The average reflectance of the five sub-samples from the same kind soil was calculated for each kind of soil. And then the same correlation analysis was conducted, for the natural samples R2=0.950, and for the dried samples R2=0.982. The results showed that the developed detector is practical. And the soil moisture has an effect on the accuracy of the detector. It is necessary to correct the real time measurement result of the detector based on soil moisture..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1146 (2010)
[in Chinese]
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 11, 2021
- Vol. 30, Issue 4, 1 (2010)
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