Journals >Spectroscopy and Spectral Analysis
Contents
2012
Volume: 32 Issue 5
67 Article(s)
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Research Article
Research on the Emission Spectrum of NO Molecule’s γ-Band System by Corona Discharge
ZHAI Xiao-dong, DING Yan-jun, PENG Zhi-min, and LUO Rui
The optical emission spectrum of the γ-band system of NO molecule, A2Σ+→X2Πr, has been analyzed and calculated based on the energy structure of NO molecule’ doublet states. By employing the theory of diatomic molecular Spectra, some key parameters of equations for the radiative transition intensity were evaluated theorThe optical emission spectrum of the γ-band system of NO molecule, A2Σ+→X2Πr, has been analyzed and calculated based on the energy structure of NO molecule’ doublet states. By employing the theory of diatomic molecular Spectra, some key parameters of equations for the radiative transition intensity were evaluated theoretically, including the potentials of the doublet states of NO molecule’s upper and lower energy levels, the electronic transition moments calculated by using r-centroid approximation method, and the Einstein coefficient of different vibrational and rotational levels. The simulated spectrum of the γ-band system was calculated as a function of different vibrational and rotational temperature. Compared to the theoretical spectroscopy, the measured results were achieved from corona discharge experiments of NO and N2. The vibrational and rotational temperatures were determined approximately by fitting the measured spectral intensities with the calculated ones..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1153 (2012)
Diagnosis of Electron Energy and Comparative Effects of OH, O or O3 on NO Oxidation in Pulsed Corona Discharge
XUAN Jian-yong, LUO Zhong-yang, ZHAO Lei, JIANG Jian-ping, and GAO Xiang
The spectrum of excited N2 molecules and ions was measured by optical emission spectroscopy in pulsed corona discharge with a wire-to-plate reactor. The ratio of emission intensities emitted by the excited molecules and ions of N2 was compared with numerical simulation to determine average electron energies and electriThe spectrum of excited N2 molecules and ions was measured by optical emission spectroscopy in pulsed corona discharge with a wire-to-plate reactor. The ratio of emission intensities emitted by the excited molecules and ions of N2 was compared with numerical simulation to determine average electron energies and electric field distributions. Within 2 cm distance from wire electrode in horizontal and vertical directions, electric field and average electron energies appear to be in the ranges of 11.05~19.6 MV·m-1 and 10.10~13.92 eV respectively; as the distance increases, average electron energies and electric field show a similar trend: first decrease and then increase. Chemically active species, such as OH, O and O3, can be generated through the energetic electron collisions with H2O and O2 directly or indirectly. For the NO oxidation, there is no coexistence of NO and O3, whereas there is a coexistence of NO and OH. NO is oxidized by O3 or O more efficiently than by OH radical..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1157 (2012)
The Influence of Laser Plasma Effects on the Characteristics of Thin Film Damage
HAN Jing-hua, DUAN Tao, GAO Xu-hua, FENG Guo-ying, FAN Wei-xing, YANG Li-ming, LIU Yan-yan, and BAO Ling-dong
Optical components with higher surface quality and higher damage threshold requirement are necessary in high-energy/power laser system, which strongly depends on the performance of optical thin films. The damage morphologies on the surface of the HfO2/SiO2 anti-reflection film, caused by focused laser pulses, were inveOptical components with higher surface quality and higher damage threshold requirement are necessary in high-energy/power laser system, which strongly depends on the performance of optical thin films. The damage morphologies on the surface of the HfO2/SiO2 anti-reflection film, caused by focused laser pulses, were investigated in the present paper. The studies revealed that the shock wave formed with the expansion of laser plasma, and its velocity and pressure decease rapidly with the radius. The spectrum of laser plasma, recorded by EEP2000 spectrometer, shows that the wavelength of laser plasma radiation is shorter than incident laser, which will increase the probability of multi-photon absorption; the photon energy in deep ultraviolet region, higher than the band gap of HfO2, can be absorbed directly. The ionization effect of laser plasma can easily induce film damage. The combination of shock wave and ionization effect determines the damage morphology of films. In the case of laser pulse focused on the film surface, the radiation and shock wave effects are the highest, not only the film is removed, but also the quartz substrate is broken-down. When the focus point is away from the film surface to a certain distance, the radiation of laser plasma and shock wave decrease rapidly, as a result, no damage can be found except that the thin-film can be peeled away from the substrate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1162 (2012)
Transient Emission Spectra from OH, CH and C2 Free Radicals in the Combustion Reaction of n-Decane
WANG Li-dong, LI Ping, ZHANG Chang-hua, TANG Hong-chang, YE Bin, and LI Xiang-yuan
Using an intensified spectroscopic detector CCD and a heated shock tube, transient emission spectra of n-decane in the combustion reaction were measured in a spectral range of 200~850 nm. Experiments were conducted at temperatures of 1 100~1 600 K, a pressure of 2.0 atm, an initial fuel mole fraction of 1.0% and an equUsing an intensified spectroscopic detector CCD and a heated shock tube, transient emission spectra of n-decane in the combustion reaction were measured in a spectral range of 200~850 nm. Experiments were conducted at temperatures of 1 100~1 600 K, a pressure of 2.0 atm, an initial fuel mole fraction of 1.0% and an equivalence ratio of 1.0. Results show that the main emission bands are attributed to OH, CH and C2 radicals produced during the combustion process of n-decane. Emission intensities of the three radicals reached their maximums only after 5 μs from the onset of their ignitions. After about 30 μs had passed, the band of OH radical was still observed, but the bands of CH and C2 radicals almost disappeared. Time histories of spectral emission intensities represent the time histories of concentrations of the three radicals during the process of combustion. The emission peak ratio of OH(306.4 nm)/CH(431.4 nm) is approximately 27/100 in the combustion of n-decane, which is much greater than the corresponding ratio of about 7/100 in the combustion of n-heptane. This result reveals that the two fuels have different reaction mechanisms. High resolution characteristic spectra of CH and C2 were also acquired in the present experiment, the spectra show the rotational structures of the bands clearly. Current results are valuable for understanding the property and validating the mechanism of n-decane combustion reaction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1166 (2012)
Terahertz Time-Domain Spectroscopy of Alpha Endosulfan Persistent Organic Pollutant
HOU Di-bo, YUE Fei-heng, KANG Xu-sheng, HUANG Ping-jie, and ZHANG Guang-xin
Frequency-dependent absorption coefficient spectrum and refractive index spectrum of alpha endosulfan, a kind of persistent organic pollutants, are presented in the terahertz frequency region by terahertz (THz) time-domain spectroscopy (TDS). The spectral features in the THz region have a number of unique characteristiFrequency-dependent absorption coefficient spectrum and refractive index spectrum of alpha endosulfan, a kind of persistent organic pollutants, are presented in the terahertz frequency region by terahertz (THz) time-domain spectroscopy (TDS). The spectral features in the THz region have a number of unique characteristic absorption peaks. The result demonstrates that THz-TDS is a promising method to identify materials. Then we adopted density functional calculation method to analyze theoretic absorption coefficients of single alpha endosulfan molecule within 0.2～2 THz. The results show that absorption peaks at 1.68, 1.91 THz in theoretical calculation correspond to 1.7, 1.88 THz in the experiment. Finally, vibrational modes and approximate assignments were discussed, showing that these matched peaks are caused by intramolecular vibrational modes of alpha endosulfan. Others might be related to intermolecular vibrational modes or combined vibrational modes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1170 (2012)
THz Spectroscopic Investigation of Energetic Ion Salt
HUANG Ping, and QIU Rui
In order to further explore the terahertz spectrum characteristics of energetic ion salts on the basis of the research on traditional nitro energetic materials, and extend applicable scope of terahertz wave technology in the study of safety testing field, experimental measurement and theoretical analysis of THz spectruIn order to further explore the terahertz spectrum characteristics of energetic ion salts on the basis of the research on traditional nitro energetic materials, and extend applicable scope of terahertz wave technology in the study of safety testing field, experimental measurement and theoretical analysis of THz spectrum for new energetic ion salts (5-ATN and BMDATHBT) were introduced. The absorption coefficient of the samples was measured in the region of 0.5~2.0 THz by time-domain spectroscopy and by Fourier transform infrared spectroscopy in the 2.0~8.0 THz region. Using the density functional theory methods, the vibration characteristics were simulated by Gaussian 03 and Materials Studio 4.3. The simulated spectrum of samples is in agreement with the experimental data. The result showed that ion salts have the typical absorption peaks that have close relation with the tribal structure, and the interaction between particles and the single skeleton vibrations of individual ion are the main reason for energetic ion salt to form absorption peak in terahertz band, which provides references for detecting high nitrogen compounds by terahertz technique..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1175 (2012)
Studies on Signal-to-Noise Ratio Standard for THz Time-Domain Spectroscope
LI Meng, HE Ming-xia, and QIN Rui
Terahertz time-domain spectroscopy (THz-TDS) is an important part of THz technology, but its low scan speed always becomes the bottleneck. In this article signals of TDS system under different scan speed were compared. The signal quality was getting worse while scan speed was increasing, and the time constant of lock-iTerahertz time-domain spectroscopy (THz-TDS) is an important part of THz technology, but its low scan speed always becomes the bottleneck. In this article signals of TDS system under different scan speed were compared. The signal quality was getting worse while scan speed was increasing, and the time constant of lock-in amplifier plays an important role in the process. The main noise was found introduced from the circuit according to the experiment results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1180 (2012)
Qualitative and Quantitative Detections of Pyrethroid Pesticides by Terahertz Time-Domain Spectroscopy
HAO Guo-hui, GUO Chang-sheng, LIU Jian-jun, and HONG Zhi
Pyrethroids pesticides are broad-spectrum insecticides which were used to control variety of pests, and were mainly used to hygienic insecticides and agricultural pest control. The room-temperature terahertz spectra of b-cypermethrin, l-cyhalothrin and deltamethrin were investigated by terahertz time-domain spectroscopPyrethroids pesticides are broad-spectrum insecticides which were used to control variety of pests, and were mainly used to hygienic insecticides and agricultural pest control. The room-temperature terahertz spectra of b-cypermethrin, l-cyhalothrin and deltamethrin were investigated by terahertz time-domain spectroscopy (THz-TDS) technology. The three pyrethroids pesticides were easily discriminated according to the absorption spectra within 0.2～2.2 THz. We employed SLR and PLS method to perform the quantitative analysis of the mixture of deltamethrin in polyethylene. The PLS method provides better result than SLR method. The detection limit of deltamethrin content in the mixture can be down to 2.0%, and the maximum value of absolute error was 0.8%. The root mean square error was 0.55%. This result proved that the THz-TDS technique is quite potential for pesticide molecular discrimination and content determination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1184 (2012)
Four Styles of Spectral Line Shape Function and Their Transformation Relation
YIN Zeng-qian, WU Chen, WANG Yong-jie, and LI Xue-chen
Four styles of spectral line shape function and their transformation relation were investigated theoretically. The photon number and energy distribution as functions of frequency and wavelength resulting from Doppler broadening were investigated, and the maximum intensity and FWHM(Full width at half maximum intensity) Four styles of spectral line shape function and their transformation relation were investigated theoretically. The photon number and energy distribution as functions of frequency and wavelength resulting from Doppler broadening were investigated, and the maximum intensity and FWHM(Full width at half maximum intensity) were obtained. The results show that the photon number distribution as function of frequency is almost the same as the energy distribution as function of frequency, while the photon number distribution as function of wavelength is almost the same as the energy distribution as function of wavelength. The method has been presented by analyzing the Doppler spectral line shape function, with which the ratio of density between two spectral lines can be obtained according to the ratio of maximum value of two spectral lines..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1189 (2012)
FTIR Spectra Investigation of Rat Sensitive Tissues Exposure to ELF-EMF
LI Gun, YAN Ya-jing, HUANG Yong, ZHOU Yan, and PANG Xiao-feng
Nonthermal effects of extremely low frequency electromagnetic fields (ELF-EMF) are related to changes in the microstructure of biological tissues after exposure to electromagnetic radiation. Fourier transform infrared spectroscopy (FTIR) analysis method can effectively study the mechanisms of biological effects of elecNonthermal effects of extremely low frequency electromagnetic fields (ELF-EMF) are related to changes in the microstructure of biological tissues after exposure to electromagnetic radiation. Fourier transform infrared spectroscopy (FTIR) analysis method can effectively study the mechanisms of biological effects of electromagnetic radiation. The present paper studies the characteristics of sensitive tissues of rat after ELF-EMF exposure. FTIR analysis of sensitive tissues of control group and experimental group showed that 50 Hz, 0.75 mT ELF-EMF exposure for 20 days can affect molecular level of the rat testis, blood and brain. Experimental results show that regular changes in absorption peak positions and intensity in the spectra of sensitive tissue may be caused by exposure to ELF-EMF, therefore, Fourier transform infrared spectroscopy is an effective means to study mechanism of biological effects of electromagnetic fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1194 (2012)
Physiological Differences between HPS/PHI Over-Expressing Transgenic and Wild-Type Geraniums under Formaldehyde Stress Revealed by FTIR Analysis
TANG Li-juan, ZHANG Ya-nan, SONG Zhong-bang, ZHANG Wei, HUANG Shu-shi, LI Kun-zhi, and Chen Li-mei
In the present study, FTIR was used to analyze changes in chemical component contents and spectra characters of 3-hexulose-6-phosphate synthase/6-phosphate-3-hexuloisomerase (HPS/PHI) over-expressing transgenic and wild-type (WT) geraniums under formaldehyde (HCHO) stress to examine if FTIR could be a new method for idIn the present study, FTIR was used to analyze changes in chemical component contents and spectra characters of 3-hexulose-6-phosphate synthase/6-phosphate-3-hexuloisomerase (HPS/PHI) over-expressing transgenic and wild-type (WT) geraniums under formaldehyde (HCHO) stress to examine if FTIR could be a new method for identification of phenotypic differences between the transgenic plants with a photosynthetic HCHO-assimilation pathway and the WT plants. The WT and transgenic geranium plants were treated with 4 mmol·L-1 HCHO for 0, 1, 2, 3 and 4 days, respectively. The comparison of FTIR spectral characteristics at different time points between the transgenic and WT plants indicated that the contents of carbohydrate, proteins and aliphatic compounds were significantly higher than those in the WT plants after 4 days of HCHO-treatment. This may be due to installation of the photosynthetic HCHO-assimilation pathway in the transgenic geranium, which enhanced its ability to metabolize and assimilate HCHO, thus allowed more HCHO to be fixed to 6-phosphate fructose, and then entered assimilation pathways for synthesis of a variety of intracellular components. The results suggest that FTIR can be a new method to identify the phenotypic differences between transgenic plants with a photosynthetic HCHO-assimilation pathway and WT plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1198 (2012)
Phase Correction Technology Research and Improvement Based on Single-Sided Interferograms in FTIR
ZHANG Min-juan, ZHANG Ji-long, WANG Zhi-bin, JING Ning, and HAO Jian
In the Fourier transform infrared spectrometers the interferograms are usually sampled by the means of the single-side beyond zero path difference and the interferograms are asymmetric. These phase-corrected technologies are researched and improved in the present paper. In the Mertz method which requires apodization toIn the Fourier transform infrared spectrometers the interferograms are usually sampled by the means of the single-side beyond zero path difference and the interferograms are asymmetric. These phase-corrected technologies are researched and improved in the present paper. In the Mertz method which requires apodization to be higher, the interferograms are apodized by these asymmetric windows so that the width of the main lobe increases and spectral resolution reduced. In order to solve these problems, a method which combines the Mertz and Forman methods is presented in the paper. In the method a double-side interferogram is constructed by the mirrored processing of the single-side interferogram beyond zero path difference, followed by the symmetric apodization, fast Fourier transform (FFT) to rebuild spectrum. And in the method high resolution phase spectrum is computed by the symmetrization of double-side interfergram to improve the phase-correction accuracy. In the experiment, these asymmetric window functions have the lower resolution compared with these symmetric window functions. And the spectrum which is acquired by the improved phase corrected method is compared with the spectra which are acquired by the Mertz and Forman methods, and the improved method has less error than Mertz, less computation than Forman, and the spectral resolution achieved 2 cm-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1203 (2012)
Recognition of Corn Seeds Based on Pattern Recognition and Near Infrared Spectroscopy Technology
LIU Tian-ling, SU Qi-ya, SUN Qun, and ANG Li-ming
Pattern recognition technology and data mining methods have become a hot topic in chemometrics. Near infrared (NIR) spectroscopic analysis has been widely used in spectrum signal processing and modeling since it has advantages of quickness, simplicity and nondestructiveness. Based on five different methods of pattern rPattern recognition technology and data mining methods have become a hot topic in chemometrics. Near infrared (NIR) spectroscopic analysis has been widely used in spectrum signal processing and modeling since it has advantages of quickness, simplicity and nondestructiveness. Based on five different methods of pattern recognition, namely the locally linear embedding (LLE), wavelet transform (WT), principal component analysis (PCA), partial least squares (PLS) and support vector machine (SVM), the pattern recognition system for corn seeds was proposed using NIR technology, and applied to classification of 108 hybrid samples and 178 female samples for corn seeds. Firstly, we get rid of noise or reduce the dimension using LLE, WT, PCA, PLS, and then use SVM to identify two-class samples. In the meantime, 1-norm SVM is the method of direct classification and identification. Experimental results of three different spectral regions show that the performances of three methods: PCA+SVM, LLE+SVM, PLS+SVM are superior to WT+SVM and 1-norm SVM methods, and obtain a high classification accuracy, which indicates the feasibility and effectiveness of the proposed methods. Moreover, this investigation provides the theoretical support and practical method for recognition of corn seeds utilizing near infrared spectral data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1209 (2012)
Research on Detection of Oil in Water Based on Near-Infrared Scattering Method
ZHAO You-quan, ZOU Rui-jie, CHEN Yu-bang, and FANG Yan-jun
The harm assessment and responsibility of marine mineral oil pollution require the content of mineral oil to be obtained by real-time online monitoring In the present paper, the method of online monitoring of the oil content in water is presented, a creative technology based on optical scattering theory was proposed. FThe harm assessment and responsibility of marine mineral oil pollution require the content of mineral oil to be obtained by real-time online monitoring In the present paper, the method of online monitoring of the oil content in water is presented, a creative technology based on optical scattering theory was proposed. Firstly the particle distribution of oil drops was scanned by Marvin laser particle meter, then with the help of the scattering signal, the crude, diesel of different concentrations from 0 to 30 mg·L-1 was measured in experiment, the linearity is more than 0.99.This paper presents a feasible setup for the online monitoring of the content of mineral oil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1213 (2012)
FTIR Spectroscopic Study of Broad Bean Diseased Leaves
LI Zhi-yong, LIU Gang, LI Lun, OU Quan-hong, ZHAO Xing-xiang, ZHANG Li, ZHOU Xiang-ping, and WANG Lu-xiang
In the present paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and normal leaves were studied using Fourier transform infrared spectroscopy combined with chemometrics. The results show that the spectra of samples were similar, only with minor differences in absorption intensIn the present paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and normal leaves were studied using Fourier transform infrared spectroscopy combined with chemometrics. The results show that the spectra of samples were similar, only with minor differences in absorption intensity of several peaks. Second derivative analyses show that the significant difference of all samples was in the range of 1 200~700 cm-1. The data in the range of 1 200~700 cm-1 were selected to evaluate correlation coefficients, hierarchical cluster analysis (HCA) and principal component analysis (PCA). Results showed that the correlation coefficients are larger than 0.928 not only between the healthy leaves, but also between the same diseased leaves. The values between healthy and diseased leaves, and among diseased leaves, are all declined. HCA and PCA yielded about 73.3% and 82.2% accuracy, respectively. This study demonstrated that FTIR techniques might be used to detect crop diseases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1217 (2012)
Prediction of Chlorophyll Content of Leaves of Oil Camelliae after Being Infected with Anthracnose Based on Vis/NIR Spectroscopy
WU Nan, LIU Jun-ang, ZHOU Guo-ying, YAN Rui-kun, and ZHANG Lei
The prediction model of chlorophyll content of leaves in canopies of oil camelliae under disease was explored and built by analyzing the Vis/NIR spectroscopy characteristics of oil camelliae canopies after being injected with anthracnose. Through field survey of disease index (DI), chlorophyll content and spectral dataThe prediction model of chlorophyll content of leaves in canopies of oil camelliae under disease was explored and built by analyzing the Vis/NIR spectroscopy characteristics of oil camelliae canopies after being injected with anthracnose. Through field survey of disease index (DI), chlorophyll content and spectral data of leaves in canopies surviving different severity of disease were acquired. The first order differential of spectral data combined with moving average filter was pretreated. The prediction model of BP neural network of chlorophyll content was built by extracting sensitive wave band from spectral resample data. The results showed that with the disease being aggravated, reflection peaks and valleys of spectra of oil camelliae canopies in visible-light region vanished gradually, steep red edges from red light to near infrared leveled little by little, and reflectivity of healthy oil camelliae was far larger than that of ill ones. The sensitive wave band of absorption and reflection of chlorophyll lay in the region of 84~512, 533~565, 586~606 and 672~724 nm. The correlation coefficient r and RMSE between predictive values calculated from BP neural network using sensitive wave band as input variables and observed values was 0.992 1 and 0.045 8 respectively. It was therefore feasible to utilize Vis/NIR spectroscopy technology to forecast the chlorophyll content of oil camelliae after being infected with anthracnose..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1221 (2012)
Study on Online Detection Modeling Parameters of Jujube Internal Quality of Southern Xinjiang with Near Infrared Spectrometric Techniques
LUO Hua-ping, LU Qi-peng, DING Hai-quan, GAO Hong-zhi, and GUO Ling
To establish the on-line near infrared spectral correction model for the jujube quality of Southern Xinjiang, the main influence factors of online testing results were analyzed, and the corresponding parameters were studied. First of all, the collecting conditions of different jujube were set, such as measurement condiTo establish the on-line near infrared spectral correction model for the jujube quality of Southern Xinjiang, the main influence factors of online testing results were analyzed, and the corresponding parameters were studied. First of all, the collecting conditions of different jujube were set, such as measurement condition, spectral region, and the parameters of the apparatus. With near infrared spectrometer and self-designed jujube batch collecting attachment, the quality spectrum of jujube was obtained, and combining spectral preprocessing and detection precision, condition parameters were selected. Secondly, through PLS spectrum correction with different modeling parameters and two-dimensional correlation spectroscopy analysis, Brix characteristic spectral parameters were selected. The results showed that with sugar degree central wavelength 9 116, 9 418 and 10 500 cm-1, acquisition resolution 16 cm-1, and scan number 8, the sugar degree relative error was 8%～10%, the size of single grain jujube spectra was reduced to 1/10 of the original, and the time was reduced to 3 seconds. It was concluded that with the experimental parameters, the spectra were compressed, a primary online correction model was established, and the jujube quality on-line detection with near infrared spectroscopy was basically realized..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1225 (2012)
Study on the Detection and Pattern Classification of Pesticide Residual on Vegetable Surface by Using Visible/Near-Infrared Spectroscopy
CHEN Rui, ZHANG Jun, and LI Xiao-long
A nondestructive testing based on visible/near-infrared reflectance spectroscopy was put forward for the common high pesticide residues of green plants in the wavelength range from 600 to 1 100 nm. Firstly, spectral features were extracted by wavelet transform from original spectral data. Secondly,the principal componeA nondestructive testing based on visible/near-infrared reflectance spectroscopy was put forward for the common high pesticide residues of green plants in the wavelength range from 600 to 1 100 nm. Firstly, spectral features were extracted by wavelet transform from original spectral data. Secondly,the principal component analysis (PCA) was done in the further analysis of spectral characteristics. Thirdly, the two PCs were applied as inputs of artificial neural network, and a multi-neuron perceptron neural network was established. Finally, It was proved that the type of pesticide residues was effectively identified and showed by classification results. In short, the study provides a new approach to the detection of pesticide residues in vegetables and fruits..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1230 (2012)
Research on the Application of Mid-Infrared Based Quantification of Water in Oil Used by Marine-Borne Machines
YANG Kun, ZHOU Xin-cong, WANG Chao, and LI Li-yao
A method that could be used to quantify the concentration of water in oil for marine-borne machine is discussed in the present paper. Water molecule has distinct absorption bands in mid-infrared section in 3 773~3 509 cm-1, so it could be applied to the quantification of water in oil. An experimental sample cell was deA method that could be used to quantify the concentration of water in oil for marine-borne machine is discussed in the present paper. Water molecule has distinct absorption bands in mid-infrared section in 3 773~3 509 cm-1, so it could be applied to the quantification of water in oil. An experimental sample cell was designed to accomplish the experiment for the convenience of sample preparation and mount in measurement, and it was designed to suit for FTIR spectrometer. The authors chose to prepare the sample oil by blending different amount of water into oil through titration. The spectra of oil with different water concentration were acquired and their integrals were calculated. The analysis of experimental result shows that the functional relationship between the integral of spectrum in 3 773~3 509 cm-1 and the percentage of water content in oil is a quadratic curve. The relative error between the fitted curve and experimental data is at the level of 0.01%. The research work in this paper presents the possibility of quantification of water content in oil through mid-infrared and gives us an idea to design a kind of new sensor based on mid-infrared LED and PIN for measure and to warn people who monitor the abnormal variation of water content in different kind of oil used in marine-borne mechanical system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1234 (2012)
FTIR Study on the Reduction of 1-Benzyl-3-Hydroxypyrrolidine-2,5-Dione
WEI Lin, and QIU Fei
The title compound was synthesized by reducing (S)-1-benzyl-3-hydroxypyrrolidine-2,5-dione with sodium borohydride-iodin. The raw material, intermediate, and the end product were characterized by IR spectra and the mechanism of reduction of imide by sodium borohydride-iodin was also studied by IR spectra. According to The title compound was synthesized by reducing (S)-1-benzyl-3-hydroxypyrrolidine-2,5-dione with sodium borohydride-iodin. The raw material, intermediate, and the end product were characterized by IR spectra and the mechanism of reduction of imide by sodium borohydride-iodin was also studied by IR spectra. According to the IR spectra, it was concluded that the product was (S)-1-bezyl-3-hydroxypyrrolidine. The mechanism of the reduction is that borane, formed in situ by reacting sodium borohydride with iodine, partly was conjugated to carbonyl to form four-member-ring intermediate and partly conjugated to nitrogen. (S)-1-benzyl-3-hydroxypyrrolidine/BH3 complex was gained when the reduction finished. The title compound was obtained by removing borane from the complex in methanol..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1238 (2012)
A Method of Temperature Measurement for Hot Forging with Surface Oxide Based on Infrared Spectroscopy
ZHANG Yu-cun, QI Yan-de, and FU Xian-bin
High temperature large forging is covered with a thick oxide during forging. It leads to a big measurement data error. In this paper, a method of measuring temperature based on infrared spectroscopy is presented. It can effectively eliminate the influence of surface oxide on the measurement of temperature. The method cHigh temperature large forging is covered with a thick oxide during forging. It leads to a big measurement data error. In this paper, a method of measuring temperature based on infrared spectroscopy is presented. It can effectively eliminate the influence of surface oxide on the measurement of temperature. The method can measure the surface temperature and emissivity of the oxide directly using the infrared spectrum. The infrared spectrum is radiated from surface oxide of forging. Then it can derive the real temperature of hot forging covered with the oxide using the heat exchange equation. In order to greatly restrain interference spectroscopy through included in the received infrared radiation spectrum, three interference filter system was proposed, and a group of optimal gap parameter values using spectral simulation were obtained. The precision of temperature measurement was improved. The experimental results show that the method can accurately measure the surface temperature of high temperature forging covered with oxide. It meets the requirements of measurement accuracy, and the temperature measurement method is feasible according to the experiment result..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1241 (2012)
A Novel Online Process Monitoring Method Based on Near Infrared Spectroscopy and Its Application to the Column Chromatographic Separation for Traditional Chinese Medicine
YANG Hui-hua, GUO Tuo, MA Jin-fang, TANG Tian-biao, LIANG Qiong-lin, WANG Yi-ming, and LUO Guo-an
Near infrared spectroscopy(NIRS) is a process analysis and monitoring tool with many advantages, while it needs to set up quantitative or discriminative calibration models in advance, and needs to adjust these models when the process conditions are varied, which makes it difficult for ordinary user to take its full advNear infrared spectroscopy(NIRS) is a process analysis and monitoring tool with many advantages, while it needs to set up quantitative or discriminative calibration models in advance, and needs to adjust these models when the process conditions are varied, which makes it difficult for ordinary user to take its full advantage of it. To tackle this problem, this paper presented a novel, simple and model-free methodology for online process monitoring based on two reciprocal viewpoints of measuring the variability of spectroscopy-both the similarity and dissimilarity of process spectrum, i.e., the adaptive moving window standard deviation function(AMWSW) and similarity function(S). The methodology was validated by a column chromatography process of traditional Chinese medicine using near infrared spectroscopy. The online trend curves of AMWSW and S obtained by proposed method were validated by a comparison with the content variation curves of multiple indicative components analyzed by high performance liquid chromatography (HPLC), and these trend curves demonstrated their potential for real-time process status monitoring, accurately determining the beginning point, the peak point, the end point of the elution, and the phase change from water solution to ethanol solution. The proposed methodology can also be used to other process analysis techniques, such as ultraviolet/visible, infrared, Raman, fluorescence, chromatograph and mass spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1247 (2012)
Mid-Infrared Distributed-Feedback Quantum Cascade Laser-Based Photoacoustic Detection of Trace Methane Gas
TAN Song, LIU Wan-feng, WANG Li-jun, ZHANG Jin-chuan, LI Lu, LIU Jun-qi, LIU Feng-qi, and WANG Zhan-guo
There have been considerable interests in methane detection based on infrared absorption spectroscopy for industrial and environment monitoring. The authors report on the realization of photoacoustic detection of methane (CH4) using mid-infrared distributed-feedback quantum cascade laser (DFB-QCL). The absorption line There have been considerable interests in methane detection based on infrared absorption spectroscopy for industrial and environment monitoring. The authors report on the realization of photoacoustic detection of methane (CH4) using mid-infrared distributed-feedback quantum cascade laser (DFB-QCL). The absorption line at 1 316.83 cm-1 was selected for CH4 detection, which can be reached by the self-manufactured DFB-QCL source operating in pulsed mode near 7.6 μm at room-temperature. The CH4 gas is filled to a Helmholtz resonant photoacoustic cell, which was equipped with a commercial electret microphone. The DFB-QCL was operated at 234 Hz with an 80 mW optical peak power. A detection limit of 189 parts per billion in volume was derived when the signal-to-noise ratio equaled 1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1251 (2012)
Characterization of Soil Calcium Carbonate Using Mid-Infrared Photoacoustic Spectroscopy
MA Zhao-yang, DU Chang-wen, and ZHOU Jian-min
The mid-infrared photoacoustic spectra of CaCO3 was determined and characterized, and multi-calibration methods of principal component regression (PCA), partial least squares regression (PLSR), and GRNN artificial neural network were applied to quantitative analysis of soil carbonate. The results showed that abundant aThe mid-infrared photoacoustic spectra of CaCO3 was determined and characterized, and multi-calibration methods of principal component regression (PCA), partial least squares regression (PLSR), and GRNN artificial neural network were applied to quantitative analysis of soil carbonate. The results showed that abundant absorptions were found in the mid-infrared photoacoustic spectra of CaCO3, especially the very strong band at the wavenumber of 1 450 cm-1, in which there was few interferences, and could be used as spectral indicator of soil carbonate; the calibration results were good or excellent with the three chemometric methods, in which PLSR and GRNN modeling were excellent with a R2 more than 0.9, and PCA modeling was good with a R2 of 0.847; the validation results showed that PLSR and PCA modeling were excellent with higher R2 values (>0.9), and GRNN was also very satisfied with a R2 of 0.882. Totally, PLSR modeling was the best with RPD values more than 3.0, indicating its strong potential in the prediction of soil carbonate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1255 (2012)
Study of Ice Ⅶ Structure Influenced by High Pressure Using Raman Spectrum
JIA Li-hua, WANG Yi-ding, MEN Zhi-wei, QU Guan-nan, LI Zuo-wei, and HE Li-qiao
Raman spectra of ice Ⅶ phase were obtained at room temperature when the pressure was from 2.5 to 23 GPa. The experimental results indicate that the oxygen atoms distance do-o of ice decreased with pressure increasing, which results in that hydrogen bond is shortened, O—H bond is lengthened, force constant is reduced, aRaman spectra of ice Ⅶ phase were obtained at room temperature when the pressure was from 2.5 to 23 GPa. The experimental results indicate that the oxygen atoms distance do-o of ice decreased with pressure increasing, which results in that hydrogen bond is shortened, O—H bond is lengthened, force constant is reduced, and Raman spectra are red shifted. The orientation order of proton (hydrogen atom) is first increased and then decreased with varying the pressure, which leads to the Raman intensity increasing and then decreasing, and Raman linewidth is decreased and then increased, and the linewidth is the least when the pressure is 13 GPa..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1259 (2012)
Resolution of Overlapping Raman Signals Based on an AdaptiveI Immune Algorithm
CAO Ling-yan, CHENG Ming-xiao, YU Zheng-wei, ZHAO Tian-qi, and LIN Jin-guo
Raman spectroscopy can be used in situ real-time measurement because it’s rapid, and it is helpful to real-time online monitoring of process control. With the complexity of the environment and the characteristics of Raman signal, it is hard to avoid some overlapping spectrum peaks. Based on the advantage of immune algoRaman spectroscopy can be used in situ real-time measurement because it’s rapid, and it is helpful to real-time online monitoring of process control. With the complexity of the environment and the characteristics of Raman signal, it is hard to avoid some overlapping spectrum peaks. Based on the advantage of immune algorithm, an immune algorithm (IA) was applied to the overlapping Raman signals of aromatics. With extraction of each single Raman spectrum peak signal from the mixture signals for resolution, Results show that the method is effective to identify the overlapped Raman signal for its fast resolution and accurate quantitative determination with the relative error less than 1%. For the overlapping Raman signals with fluorescence background disturbance, we proposed an adaptive immune algorithm, which is combined with independent component analysis. It can effectively resolve the fluorescence background signal, and it provides a new way for Raman spectra analysis of complex samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1262 (2012)
Rapid Detection of 6-Benzylaminopurine Residues in Sprout Beans by Surface-Enhanced Raman Spectroscopy
ZHANG Ping, ZHENG Da-wei, LIU Jing, ZHONG Ru-gang, LIU Chun-wei, GUO Xun, and WANG Hong
New method for rapid and quantitative analysis of 6-benzylaminopurine (6-BA) residues in sprout beans was studied by using FAST-SPE and portable surface-enhanced Raman spectroscopy (SERS). With homemade sprout bean samples as blank control, 6-BA solutions extracted from inserted-treatment samples showed typical charactNew method for rapid and quantitative analysis of 6-benzylaminopurine (6-BA) residues in sprout beans was studied by using FAST-SPE and portable surface-enhanced Raman spectroscopy (SERS). With homemade sprout bean samples as blank control, 6-BA solutions extracted from inserted-treatment samples showed typical characteristic Raman peaks at 1 002 cm-1 tested by SERS, and normalized 1 002 cm-1 intensities had a good linear relationship with gradient concentrations of 6-BA insert-standard solutions. The high concentration linear range was 0.5～14 μg·mL-1, and the low one was 0.1～2 μg·mL-1. The quantitative detection limit was down to 0.02 mg·kg-1 that was below the maximum allowable residues (MAL) of 0.2 mg·kg-1 in related National Standard. The recoveries were 82.3%～95.1% and the RSD was below 5%. This method with portable equipment and simple pre-treatment showed good reproducibility, short test time-consuming and easy operating, and thus it would provide efficient and sensitive solutions for large-scale on-site and rapid detections..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1266 (2012)
Research on the Mineral Phase and Component of Non-Crystalline and Nano-Crystalline Corrosion Products on Bronzes Unearthed from Shang Tomb in Xingan
CHENG Xiao-lin, and PAN Lu
The patinas on bronzes in Shang Tomb of Xingan were powdery, pale green, which were more like “bronze disease”, but the mineral composition of patinas was not paratacamite or atacamite. Micro X-ray diffraction (XRD) and high performance transmission electroscope (HTEM) showed that the patinas were mainly composed of noThe patinas on bronzes in Shang Tomb of Xingan were powdery, pale green, which were more like “bronze disease”, but the mineral composition of patinas was not paratacamite or atacamite. Micro X-ray diffraction (XRD) and high performance transmission electroscope (HTEM) showed that the patinas were mainly composed of non-crystalline and nano-crystalline SnO2, and the size of nano-crystalline particle was in the range of 4～5.7 nm; Moreover, the energy-dispersive X-ray spectrometry showed that element tin is the primary ingredient of the sample, as well as little copper, silicon, lead and iron were detected. By studying the crystal lattice stripe image of the nanometer SnO2, it was deduced that the chemical formula of nano-crystalline SnO2 did not include other elements; The Raman spectrum of the sample showed that there were not any characteristic peaks of SnO2, the spectrum was more like non-crystalline SnO2, and the weak and broad peak of 973 cm-1 indicated that the sample may contain silicate grains, It was inferred that little of copper, silicon, lead and iron should exist in the form of non-crystalline silicate particles..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1270 (2012)
An SVM Real-Time Method by Utilizing Curvelet Transform in Nonlinear Laser-Induced Fluorescence of Oil Recognition
LI Ying, CHEN Peng, LAN Guo-xin, and YU Chun-yan
This paper presents a real-time nonlinear laser fluorescence recognition method. First, the feature vectors consisting of transform coefficients were obtained by utilizing the three layers curvelet transform to decompose the pre-processing fluorescence spectrum of the heavy oil, diesel, crude oil and other types of comThis paper presents a real-time nonlinear laser fluorescence recognition method. First, the feature vectors consisting of transform coefficients were obtained by utilizing the three layers curvelet transform to decompose the pre-processing fluorescence spectrum of the heavy oil, diesel, crude oil and other types of common oils in various angles and different scales. Then the feature vectors were regarded as the parameters and sent into the support vector Machines (SVM) for training. Finally, the trained SVM was used for spectral classification of the oil slicks. Results from the trial suggest that it didn’t rely on a large number of samples, so that the number of support vectors was significantly reduced and the operation time was shortened for real-time running. Compared with traditional methods, the proposed method proves to be more efficient, faster and more reliable and has real-time capabilities..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1274 (2012)
Fluorescent Labeling of Latent Fingerprints with PAMAM Capped ZnS QDs
JIN Yu-juan, DUAN Xiao-bo, WANG Chong-zheng, and ZHANG Wan-lu
Stable PAMAM(polyamidoamine) capped ZnS (zinc sulfide) QDs (quantum dots) were prepared and characterized with UV-Vis spectrum and PL(photoluminescence) emission spectrum on the base of coordination of Zn2+ ions with PAMAM dendrimers. The results show that Zn2+ ions coordinated with N atoms of PAMAM ligand and the satuStable PAMAM(polyamidoamine) capped ZnS (zinc sulfide) QDs (quantum dots) were prepared and characterized with UV-Vis spectrum and PL(photoluminescence) emission spectrum on the base of coordination of Zn2+ ions with PAMAM dendrimers. The results show that Zn2+ ions coordinated with N atoms of PAMAM ligand and the saturated coordinating time is about 6 h; PAMAM capped ZnS QDs emitted strong blue light under the irradiation of UV light at the wavelength of 365 nm, and the PL emission peak is at about 500 nm. Finally, the prepared PAMAM capped ZnS QDs were applied in the fluorescent labeling of latent fingerprints on tinfoils; Latent fingerprints emitting strong blue light and were successfully detected with good resolving rate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1278 (2012)
A Novel Method for Extracting Leaf-Level Solar-Induced Fluorescence of Typical Crops under Cu Stress
QU Ying, LIU Su-hong, and LI Xiao-wen
The leaf-level solar-induced fluorescence changes when the typical crops are under Cu stress, which can be considered as a sensitive indicator to estimate the stress level. In the present study, wheat (TritiZnm aestivum L.), pea (Pisum sativum L.) and Chinese cabbage (Brassica campestris L.) were selected and cultured The leaf-level solar-induced fluorescence changes when the typical crops are under Cu stress, which can be considered as a sensitive indicator to estimate the stress level. In the present study, wheat (TritiZnm aestivum L.), pea (Pisum sativum L.) and Chinese cabbage (Brassica campestris L.) were selected and cultured with copper solutions or copper polluted soil with different Cu stress. The apparent reflectance of leaves was measured by an ASD Fieldspec spectrometer and an integrating sphere. As the apparent reflectance was seldom affected by the fluorescence emission at 580~650 and 800~1 000 nm, so the apparent solar-induced fluorescence can be separated from the apparent reflectance based on PROSPECT model. The re-absorption effect of chlorophyll was corrected by three methods, called GM (Gitelson et al.’s model), AM (Agati et al.’s model) and LM (Lagorio et al.’s model). After the re-absorption correction, the solar-induced fluorescence under different Cu stress was obtained, and a positive relationship was found between the height of far RED fluorescence (FRF) and the copper contents in leaves..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1282 (2012)
Monitoring the Chlorophyll Fluorescence Parameter Fv/Fm in Compact Corn Based on Different Hyperspectral Vegetation Indices
TAN Chang-wei, HUANG Wen-jiang, JIN Xiu-liang, WANG Jun-chan, TONG Lu, WANG Ji-hua, and GUO Wen-shan
In order to further assess the feasibility of monitoring the chlorophyll fluorescence parameter Fv/Fm in compact corn by hyperspectral remote sensing data, in the present study, hyperspectral vegetation indices from in-situ remote sensing measurements were utilized to monitor the chlorophyll fluorescence parameter Fv/FIn order to further assess the feasibility of monitoring the chlorophyll fluorescence parameter Fv/Fm in compact corn by hyperspectral remote sensing data, in the present study, hyperspectral vegetation indices from in-situ remote sensing measurements were utilized to monitor the chlorophyll fluorescence parameter Fv/Fm measured in the compact corn experiment. The relationships were analyzed between hyperspectral vegetation indices and Fv/Fm, and the monitoring models were established for Fv/Fm in the whole growth stages of compact corn. The results indicated that Fv/Fm was significantly correlated to the hyperspectral vegetation indices. Among them, structure-sensitive pigment index (SIPI) was the most sensitive remote sensing variable for monitoring Fv/Fm with correlation coefficient (r) of 0.88. The monitoring model of Fv/Fm was established on the base of SIPI, and the determination coefficients (r2) and the root mean square errors (RMSE) were 0.812 6 and 0.082 respectively. The overall results suggest that hyperspectral vegetation indices can be potential indicators to monitor Fv/Fm during growth stages of compact corn..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1287 (2012)
Chlorophyll Fluorescence Spectrum Analysis of Greenhouse Cucumber Disease and Insect Damage
SUI Yuan-yuan, YU Hai-ye, ZHANG Lei, LUO Han, REN Shun, and ZHAO Guo-gang
The present paper is based on chlorophyll fluorescence spectrum analysis. The wavelength 685 nm was determined as the primary characteristic point for the analysis of healthy or disease and insect damaged leaf by spectrum configuration. Dimensionality reduction of the spectrum was achieved by combining simple intercorrThe present paper is based on chlorophyll fluorescence spectrum analysis. The wavelength 685 nm was determined as the primary characteristic point for the analysis of healthy or disease and insect damaged leaf by spectrum configuration. Dimensionality reduction of the spectrum was achieved by combining simple intercorrelation bands selection and principal component analysis (PCA). The principal component factor was reduced from 10 to 5 while the spectrum information was kept reaching 99.999%. By comparing and analysing three modeling methods, namely the partial least square regression (PLSR), BP neural network (BP) and least square support vector machine regression (LSSVMR), regarding correlation coefficient of true value and predicted value as evaluation criterion, eventually, LSSVMR was confirmed as the appropriate method for modeling of greenhouse cucumber disease and insect damage chlorophyll fluorescence spectrum analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1292 (2012)
Research on Retrieving Thermospheric O/N2 from FUV Remote Sensing
PENG Sheng-feng, TANG Yi, WANG Jing, ZHENG Xu-li, NAN Yi-bing, and NI Guo-qiang
Magnetic storms usually cause significant departures of thermospheric O and N2 from their normal values. To study the effects on thermospheric neutral species caused by magnetic storms, a method to retrieve thermospheric O/N2 based on the data obtained from global ultraviolet imager on board TIMED is presented. With thMagnetic storms usually cause significant departures of thermospheric O and N2 from their normal values. To study the effects on thermospheric neutral species caused by magnetic storms, a method to retrieve thermospheric O/N2 based on the data obtained from global ultraviolet imager on board TIMED is presented. With the help of AURIC, the normalizations of observing angles and SZAs were preformed to the measurements and a relationship between 135.6/LBHs and O/N2 was established. Finally, applying the proposed method to retrieve O/N2 during a magnetic period（29, September—4, October, 2002）, it was shown that magnetic storms could induce significant O/N2 depletion, extending from the polar regions towards the equator..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1296 (2012)
A Novel Technology for Water Quality Testing Based on UV Spectral Analysis
ZHAO You-quan, LI Yu-chun, GUO Yi, GU Bai-jun, and YANG Zhen
Water pollution control and prevention require that the water quality testing is of real time, online and portability. The presejt paper provides a water detecting system based on UV-visible spectra. The R2 of the linear regression is greater than 0.99 between absorbance and COD of the samples. Single measurement is wiWater pollution control and prevention require that the water quality testing is of real time, online and portability. The presejt paper provides a water detecting system based on UV-visible spectra. The R2 of the linear regression is greater than 0.99 between absorbance and COD of the samples. Single measurement is within 1s. At the same time, two methods were presented for direct comparison and normalization of the spectra and their corresponding indicator parameters. By a large number of experiments with standard solution of the potassium hydrogen phthalate and water samples, we found that these methods can be used to classify samples, find suitable mathematical model of the test water from the database, to improve the universal ability of the UV water testing technology, and get other water quality indices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1301 (2012)
Research on the DNA Condensation Properties by Ultraviolet Spectrum
ZHANG Jing, HU Lin, LIU Yan-hui, and ZHANG Bi-cheng
In order to explore the property and mechanism of DNA condensation, the authors studies the effect of different concentrations of spermine(SPM), spermidine(SPD) and hexamminecobalt(Ⅲ) chloride on the ultraviolet(UV) absorption value of calf thymus DNA by UV spectrophotometer from the macro. The results showed that SPD In order to explore the property and mechanism of DNA condensation, the authors studies the effect of different concentrations of spermine(SPM), spermidine(SPD) and hexamminecobalt(Ⅲ) chloride on the ultraviolet(UV) absorption value of calf thymus DNA by UV spectrophotometer from the macro. The results showed that SPD and SPM interaction with the DNA had the similar characteristics in UV spectrum. The UV absorption value of calf thymus DNA at 260 nm appeared increased-decreased-increased with the increasing the concentration of SPD and SPM. The value of hexamminecobalt(Ⅲ) chloride system showed decreased and then increased, suggesting that SPM, SPD and hexamminecobalt(Ⅲ) chloride could make DNA condense, but in different ways. Relatively, hexamminecobalt(Ⅲ) chloride was more sensitive than SPD and SPM. The result of UV spectral analysis coincided with recent single-molecule experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1306 (2012)
Vegetation Stress Spectra and Their Relations with the Contents of Metal Elements within the Plant Leaves in Metal Mines in Heilongjiang
CHEN Sheng-bo, ZHOU Chao, and WANG Jin-nian
In this paper, Duobao Mt. and Tong Mt. were taken as examples. The spectra of the crown or leaf of the vegetation were collected. Fourteen metal elements in the rock, soil (A, B, C) and vegetation (root, trunk, leaf), and biological chemical parameters were measured. It was indicated that different metal elements were In this paper, Duobao Mt. and Tong Mt. were taken as examples. The spectra of the crown or leaf of the vegetation were collected. Fourteen metal elements in the rock, soil (A, B, C) and vegetation (root, trunk, leaf), and biological chemical parameters were measured. It was indicated that different metal elements were selected and enriched in different vegetation. The red edge position (REP) and the absorbing depth are related to biological chemical parameters. A multivariable regression equation was built between the absorption depths and the contents of metal elements. The relative coefficients between the absorbing depths and chemical elements, including Co, Cu, N, Mo, Ag, Sb, W, Pb and As, are greater than 0.75. Thus, it is important to analyze and measure the contents of metal elements by hyper-spectral remote sensing of vegetation stress spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1310 (2012)
Simultaneous Detection of Phenol and Anionic Surfactant in Water Based on Continuous Spectrum
ZHOU Lan, MO Zhi-hong, WEN Zhi-yu, and WEI Wen-jing
Phenol and anionic surfactant are important indices for water-quality. Based on improvement and optimization of standard methods (spectrophotometry) for the two indices, we integrated the respective two color-extractants into a composited reagent. Using a self-developed microspectrometer with a design of splitting behiPhenol and anionic surfactant are important indices for water-quality. Based on improvement and optimization of standard methods (spectrophotometry) for the two indices, we integrated the respective two color-extractants into a composited reagent. Using a self-developed microspectrometer with a design of splitting behind and collection of continuous spectrum signal (340~770 nm) in real time, a compound detection system was constructed. This system could simultaneously detect phenol and anionic surfactant in water without chemical and spectral interferences, leading to great decreases in reagent amount and detection time. The detection limits for phenol and anionic surfactant are 0.003 and 0.016 mg·L-1, respectively. This method was applied to water-quality monitoring of real samples in comparison with standard methods, and the results indicated that its reproducibility (relative standard deviation, n=5) and accuracy (relative error to results by standard methods) were less than 5%, contenting with the related standard..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1316 (2012)
Study on the Spectrophotometric Determination of Hydroxyl Free Radical from Low Power Trench-Type Ultrasound
CAO Yan-ping, YUAN Ying-mao, and ZHU Yu-chen
Under the condition of different pH (7~11) and different ethanol volume fraction (45% to 85%), the ultraviolet-visible absorption spectra of malachite green were studied in neutral and alkaline ethanol solution, the maximum absorption wavelength at 620 nm was found, and the matching degree of standard curve was better Under the condition of different pH (7~11) and different ethanol volume fraction (45% to 85%), the ultraviolet-visible absorption spectra of malachite green were studied in neutral and alkaline ethanol solution, the maximum absorption wavelength at 620 nm was found, and the matching degree of standard curve was better established. In low power trench-type ultrasound apparatus, the absorption of the malachite green solution was measured under ultrasound and non-ultrasound, respectively. the difference values of the ultraviolet absorption of the malachite green solution under low power trench-type ultrasound were measured results of the hydroxyl free radical oxidation degrading malachite green, therefore hydroxyl free radical from low power trench-type ultrasound was determined indirectly. Then the contents of hydroxyl free radical in four conditions were measured. The detection limit of the method of 8.4×10-6 mmol·L-1 and the relative standard deviation of the method of 9.4×10-5～3.7×10-4 mmol·L-1 were determined, a higher testing precision and good reproducibility were confirmed. It can be applied for fast detection of neutral and alkaline ethanol solution system in the case of very low concentration of hydroxyl free radicals. Since malachite green is heat sensitive, so compared to measuring temperature, the method possessed better functions for thermal effects of ultrasound..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1320 (2012)
Contrastive Study on Dynamic Spectrum Extraction Method
LI Gang, ZHOU Mei, WANG Hui-quan, XIONG Chan, and LIN Ling
Dynamic spectrum method extracts the absorbance of the artery pulse blood with some wavelengths. The method can reduce some influence such as measurement condition, individual difference and spectrum overlap. It is a new way for noninvasive blood components detection. However, how to choose a dynamic spectrum extractioDynamic spectrum method extracts the absorbance of the artery pulse blood with some wavelengths. The method can reduce some influence such as measurement condition, individual difference and spectrum overlap. It is a new way for noninvasive blood components detection. However, how to choose a dynamic spectrum extraction method is one of the key links for the weak ingredient spectrum signal. Now there are two methods to extract the dynamic spectral signal—frequency domain analysis and single-trial estimation in time domain. In the present research, comparison analysis and research on the two methods were carrued out completely. Theoretical analysis and experimental results show that the two methods extract the dynamic spectrum from different angles. But they are the same in essence—the basic principle of dynamic spectrum, the signal statistical and average properties. With the pulse wave of relative stable period and amplitude, high precision dynamic spectrum can be obtained by the two methods. With the unstable pulse wave due to the influence of finger shake and contact-pressure change, the dynamic spectrum extracted by single-trial estimation is more accurate than the one by frequecy domain analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1324 (2012)
In Situ Temperature Measurement by Absorption Spectroscopy Based on Time Division Multiplexing Technology
LOU Nan-zheng, LI Ning, and WENG Chun-sheng
Tunable diode laser absorption spectroscopy (TDLAS) technology is a kind of high sensitivity, high selectivity of non contacting gas in situ measurement technique. In the present paper, in situ gas temperature measurement of an open environment was achieved by means of direct scanning multiple characteristic lines of HTunable diode laser absorption spectroscopy (TDLAS) technology is a kind of high sensitivity, high selectivity of non contacting gas in situ measurement technique. In the present paper, in situ gas temperature measurement of an open environment was achieved by means of direct scanning multiple characteristic lines of H2O and combined with least-squares algorithm. Through the use of HITRAN spectral database, the boundary effect on the gas temperature and concentration measurements was discussed in detail, and results showed that the combination of scanning multiple characteristic lines and least-squares algorithm can effectively reduce the boundary effect on the gas temperature measurements under the open environment. Experiments using time division multiplexing technology to simultaneously scan 7 444.36, 7 185.60, 7 182.95 and 7 447.48 cm-1, the four characteristic H2O lines, the gas temperature of tubular furnace in the range of 573~973 K was measured under different conditions. The maximum temperature difference between absorption spectrum measurement and thermocouple signal was less than 52.4 K, and the maximum relative error of temperature measurement was 6.8%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1329 (2012)
Theoretical Analysis of the Residual Amplitude Modulation of Frequency Modulation Strong Absorption Spectroscopy
ZHANG Hu, ZHANG Yong-zhi, YIN Zhao-xia, WANG Xiao-bo, and MA Wei-guang
The application of frequency modulation(FM) spectroscopy technology in the trace gas detection is greatly restricted by the residual amplitude modulation(RAM) which induced by the birefringence of the electro-optic modulator(EOM) and the misaligned linear polarization direction of laser to the EOM. Based on the interacThe application of frequency modulation(FM) spectroscopy technology in the trace gas detection is greatly restricted by the residual amplitude modulation(RAM) which induced by the birefringence of the electro-optic modulator(EOM) and the misaligned linear polarization direction of laser to the EOM. Based on the interaction between the laser field and crystal, a lineshape expression of the FM spectroscopy with RAM is obtained. The angle between the polarization direction of input light and the principle axis of EOM, θ, the phase difference between the two principle axes of electro-optic crystal, Δ, and the modulation index FM, β, are the major factors to influence the lineshape. The larger θ and larger Δ are, the stronger distortion of the lineshape is. Meanwhile a DC offset exists in the FM dispersion spectroscopy which is influenced by θ and Δ. Finally a servo control of θ and Δ is suggested to reduce the RAM. These phenomenon and the analysis of the lineshape provide a necessary technical support for the fiber components based FM spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1334 (2012)
High Transmission and Low Group Velocity of a Photonic Crystal Coupled-Cavity Waveguide
ZHANG Chang-xin, and XU Xing-sheng
A two-dimensional photonic crystal coupled-cavity waveguide was designed and optimized by combining photonic crystal wavguide and cavity, transmission spectra of the waveguide were calculated by using FDTD method, and the transmittance and the group velocity were obtained through the transmission spectra. The calculatiA two-dimensional photonic crystal coupled-cavity waveguide was designed and optimized by combining photonic crystal wavguide and cavity, transmission spectra of the waveguide were calculated by using FDTD method, and the transmittance and the group velocity were obtained through the transmission spectra. The calculation results show that a group velocity of vg＝ｃ/130 and corresponding transmission of 20.1% can be obtained at wavelength 1.551 μm, and a group velocity of ｖｇ＝ｃ／50 and transmission of 29.2% was obtained at wavelength 1.502 μm. The slow light in the waveguide was also analyzed by using photonic bandstructure calculated by plane-wave-expansion (PWE) method. The results of the photonic crystal waveguide with high transmission and low group velocity will have potential application in optical storage, optical delay and photonic integration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1339 (2012)
Polarization-Sensitive Characteristics of the Transmission Spectra in Photonic Crystal with Nematic Liquid Crystal Defects
DAI Qin, WU Ri-na, YAN Bin, ZHANG Rui-liang, WANG Peng-chong, QUAN Wei, and XU Song-ning
The polarization-sensitive characteristics in the transmission spectra of TiO2/SiO2 optical multilayer films of one-dimensional photonic crystal(1D PC) with nematic liquid crystal defects were investigated in the present paper. The transmission spectra measurements and simulated results show that the polarization-sensiThe polarization-sensitive characteristics in the transmission spectra of TiO2/SiO2 optical multilayer films of one-dimensional photonic crystal(1D PC) with nematic liquid crystal defects were investigated in the present paper. The transmission spectra measurements and simulated results show that the polarization-sensitive feature was obvious when natural light was normal incident onto the parallelly aligned nematic liquid crystal. There were peaks of the extraordinary light (TE mode) with center wavelengths 1 831 and 1 800 nm and the ordinary light (TM mode) with center wavelengths 1 452 and 1 418 nm in the photonic forbidden band, respectively. With applied voltage increasing, the peaks of the extraordinary light was blue-shifted, and coincided with the peaks of O light gradually. Their tunable ranges were about 31 and 34 nm, respectively. For the random nematic liquid crystal, polarization sensitivity was not observed. Meanwhile, an individual extraordinary light peak with center wavelength 1 801 nm and an individual ordinary light peak with center wavelength 1 391 nm were obtained in the photonic forbidden band, respectively. The peaks were also found blue-shifted with applied voltage increasing, and their tunable ranges were about 64 and 15 nm, respectively. The polarization insensitive photonic crystal with nematic liquid crystal defects can be achieved by random liquid crystal molecules, which make the effective refractive index of the extraordinary light equal to that of the ordinary light..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1345 (2012)
Study on Predicting Protein Content of Wheat Seeds by Using Wheat Leaves SPAD Value
GAO Fei, XIAO Jing, GU Yun-hong, JIAO Zhen, and JIN Qing-sheng
The present paper is to study and build the rapid nondestructive prediction technique of wheat grain quality in the pre-harvest period, The analysis of SPAD value aimed at five different periods from the first leaf to the 4th leaf to obtain SPAD values with the sampling period and the changes of leaf using 31 kinds of The present paper is to study and build the rapid nondestructive prediction technique of wheat grain quality in the pre-harvest period, The analysis of SPAD value aimed at five different periods from the first leaf to the 4th leaf to obtain SPAD values with the sampling period and the changes of leaf using 31 kinds of wheat materials, near infrared spectroscopy was used for the determination of protein of the grain. And the leaf SPAD values and maturity correlation of grain protein content were established. It was found that decreasing rate of the top leaf SPAD and grain protein content showed significant negative correlation y=-3.210 9x+14.286, linear regression equation is y=-3.210 9x+14.286, and correlation coefficient is r=-0.849 0. With significant analysis, we assume that there is a very significant linear correlation between decreasing rate of the top leaf SPAD value and grain protein content. So we can use decreasing rate of the top leaf SPAD values to predict the protein content of grain..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1350 (2012)
Research on the Carbon Content of Coal by LIBS
YIN Wang-bao, ZHANG Lei, WANG Le, LI Zhi-xin, YAN Xiao-juan, ZHANG Yong-zhi, and JIA Suo-tang
A method is introduced about quantitative analysis of carbon in coal by LIBS (laser-induced breakdown spectroscopy) in the present paper, and it introduces data optimization technology and method based on spectral data integration, normalization and data screening processing to overcome the poor quality of precision inA method is introduced about quantitative analysis of carbon in coal by LIBS (laser-induced breakdown spectroscopy) in the present paper, and it introduces data optimization technology and method based on spectral data integration, normalization and data screening processing to overcome the poor quality of precision in the analysis because of laser source energy fluctuation, self-absorption, sample surface roughness etc. It is showed that the standard deviation（SD）is less than 1.6% using the method to analyze C element content in coal, and this method also can be used for other element analysis for coal..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1355 (2012)
Study of Cortex Phellodendri Chinensis Decoction Experiment Based on the Spectral Imaging Technology
LIANG Lan, WANG Lin, PANG Qi-chang, CHEN Zhen-qiang, CUI Dai-jun, HU Cui-ying, MENG Qing-xia, ZHAO Jing, and MA Ji
The purpose of decoction traditional Chinese medicine is to make full exhalation of medicinal materials active ingredients, thus it has the maximum effect of traditional Chinese medicine to treat disease. In order to detect the dissolution change of medicinal materials active ingredients in decoction process, this papeThe purpose of decoction traditional Chinese medicine is to make full exhalation of medicinal materials active ingredients, thus it has the maximum effect of traditional Chinese medicine to treat disease. In order to detect the dissolution change of medicinal materials active ingredients in decoction process, this paper applys spectral imaging technology, with Chinese traditional medicine cortex phellodendri as an example, discussing its fluorescence intensity at different time in decoction process. And the analysis results reflect edgewise the dissolution rule of cortex phellodendri active ingredients..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1359 (2012)
Estimated Nitrogen Nutrition Index Based on the Hyperspectral for Wheat of Drip Irrigation under Mulch
DIAO Wan-ying, LI Shao-kun, WANG Ke-ru, JIN Xiu-liang, WANG Fang-yong, CHEN Bing, WANG Qiong, WANG Kai, and XIAO Chun-hua
The accurate wheat management needs a reasonable nitrogen application, and it is one of the key measures for real-time and quantitatively monitoring of nitrogen status to gain the higher yield of wheat. In the present study, two field experiments were conducted with different nitrogen stress and wheat cultivars, the reThe accurate wheat management needs a reasonable nitrogen application, and it is one of the key measures for real-time and quantitatively monitoring of nitrogen status to gain the higher yield of wheat. In the present study, two field experiments were conducted with different nitrogen stress and wheat cultivars, the relationship was analyzed between spectral parameters and the partial factor productivity from applied N (PFPn), and the estimating model was established for PFPn in the growth stages of wheat. The result indicated that there was a highly significant correlation between the PFPn and GreenNDVI at jointing, the correlation coefficient (r) was 0.640 4, the estimating model of PFPn was established, and the root mean square errors(RMSE) was 0.459 7. The result indicated that the PFPn can be effectively estimated by using spectral parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1362 (2012)
Hyperspectral Estimation Models of Chlorophyll Content in Apple Leaves
LIANG Shuang, ZHAO Geng-xing, and ZHU Xi-cun
The present study chose the apple orchard of Shandong Agricultural University as the study area to explore the method of apple leaf chlorophyll content estimation by hyperspectral analysis technology. Through analyzing the characteristics of apple leaves’ hyperspectral curve, transforming the original spectral into firThe present study chose the apple orchard of Shandong Agricultural University as the study area to explore the method of apple leaf chlorophyll content estimation by hyperspectral analysis technology. Through analyzing the characteristics of apple leaves’ hyperspectral curve, transforming the original spectral into first derivative, red edge position and leaf chlorophyll index (LCI) respectively, and making the correlation analysis and regression analysis of these variables with the chlorophyll content to establish the estimation models and test to select the high fitting precision models. Results showed that the fitting precision of the estimation model with variable of LCI and the estimation model with variable of the first derivative in the band of 521 and 523 nm was the highest. The coefficients of determination R2 were 0.845 and 0.839, the root mean square errors RMSE were 2.961 and 2.719, and the relative errors RE% were 4.71% and 4.70%, respectively. Therefore LCI and the first derivative are the important index for apple leaf chlorophyll content estimation. The models have positive significance to guide the production of apple cultivation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1367 (2012)
Research on the Method of Copper Converting Process Determination Based on Emission Spectrum Analysis
LI Xian-xin, LIU Wen-qing, ZHANG Yu-jun, SI Fu-qi, DOU Ke, WANG Feng-ping, HUANG Shu-hua, FANG Wu, WANG Wei-qiang, and HUANG Yong-feng
A method of copper converting process determination based on PbO/PbS emission spectrum analysis was described. According to the known emission spectrum of gas molecules, the existence of PbO and PbS was confirmed in the measured spectrum. Through the field experiment it was determined that the main emission spectrum ofA method of copper converting process determination based on PbO/PbS emission spectrum analysis was described. According to the known emission spectrum of gas molecules, the existence of PbO and PbS was confirmed in the measured spectrum. Through the field experiment it was determined that the main emission spectrum of the slag stage was from PbS, and the main emission spectrum of the copper stage was from PbO. The relative changes in PbO/PbS emission spectrum provide the method of copper converting process determination. Through using the relative intensity in PbO/PbS emission spectrum the copper smelting process can be divided into two different stages, i.e. the slag stage (S phase) and the copper stage (B phase). In a complete copper smelting cycle, a receiving telescope of appropriate view angle aiming at the converter flame, after noise filtering on the PbO/PbS emission spectrum, the process determination agrees with the actual production. Both the theory and experiment prove that the method of copper converting process determination based on emission spectrum analysis is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1371 (2012)
Analytical Figures of Merit of Hildebrand Grid and Ultrasonic Nebulizations in Inductively Coupled Plasma Atomic Emission
TIAN Mei, HAN Xiao-yuan, ZHUO Shang-jun, and ZHANG Rui-rong
Hildebrand grid nebulizer is a kind of improved Babington nebulizer, which can nebulize solutions with high total dissolved solids. And the ultrasonic nebulizer(USN) possesses advantage of high nebulization efficiency and fine droplets. In the present paper, the detection limits, matrix effects, ICP robustness and memoHildebrand grid nebulizer is a kind of improved Babington nebulizer, which can nebulize solutions with high total dissolved solids. And the ultrasonic nebulizer(USN) possesses advantage of high nebulization efficiency and fine droplets. In the present paper, the detection limits, matrix effects, ICP robustness and memory effects of Hildebrand grid and ultrasonic nebulizers for ICP-AES were studied. The results show that the detection limits using USN are improved by a factor of 6～23 in comparison to Hildebrand grid nebulizer for Cu, Pb, Zn, Cr, Cd and Ni. With the USN the matrix effects were heavier, and the degree of intensity enhancement and lowering depends on the element line, the composition and concentrations of matrices. Moreover, matrix effects induced by Ca and Mg are more significant than those caused by Na and Mg, and intensities of ionic lines are affected more easily than those of atomic lines. At the same time, with the USN ICP has less robustness. In addition, memory effect of the USN is also heavier than that of Hildebrand grid nebulizer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1376 (2012)
Determination of Trace Element Contents in Urtica laetevirens Maxim. Reaped in Different Months by ICP-MS
CHI Xiao-feng, JIAO Xiao-li, JI Tian, DONG Qi, XIAO Yuan-can, and HU Feng-zu
The contents of twenty kinds of trace elements, Al, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S and Zn, were determined by ICP-MS with microwave digestion in Urtica laetevirens Maxim. The recovery(n=7) is 95.4%～101.2%, and the RSD(n=7) is 1.2%～5.3%. The contents of K, P, S, Ca and Na in the samples wereThe contents of twenty kinds of trace elements, Al, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S and Zn, were determined by ICP-MS with microwave digestion in Urtica laetevirens Maxim. The recovery(n=7) is 95.4%～101.2%, and the RSD(n=7) is 1.2%～5.3%. The contents of K, P, S, Ca and Na in the samples were abundant while Fe, Mg, Mn and Zn were less abundant. The contents of Al, Cr and Pb which were harmful to human were kept at low level. The contents of trace elements in Urtica laetevirens Maxim. also showed obvious seasonal dynamics. This result provides some theoretical basis for the study of internal relations between trace elements in Urtica laetevirens Maxim. and its efficacy. It’s also useful for better development and utilization of the resource..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1381 (2012)
Determining of the Content of Determination of Elements of Pedicularis from Different Places by ICP-MS after Micriware-Assisted Digestion
ZHAO Xiao-hui, LI Yu-lin, XU Wen-hua, SUN Jing, and CHEN Gui-chen
The content of elements in Pedicularis was determined by ICP-MS aftermicriware-assisted digestion. Recovery and RSD of the method is 95%~102% and 1.24%~2.18% respectively, and the method is rapid and precise. There is different Element content in Pedicularis from different places. There are some relations between altitThe content of elements in Pedicularis was determined by ICP-MS aftermicriware-assisted digestion. Recovery and RSD of the method is 95%~102% and 1.24%~2.18% respectively, and the method is rapid and precise. There is different Element content in Pedicularis from different places. There are some relations between altitude and content in different places. The result of Pedicularis can provide theoretical basis for medicine research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1384 (2012)
Determination of Gold and Silver in Twenty Plants from the Copper Mining Area by Inductively Coupled Plasma-Mass Spectrometry
SHI Yi-hua, YANG Zhong-ping, SONG Ci-an, QIU Li, and HU Sheng-hong
The preconcentration and determination of gold and silver in twenty plants from the copper mining area by ICP-MS was described. The plant samples were decomposed by dry-ashing and aqua regia. 107Ag, 109Ag and 197Au were chosen as determining isotopes and 103Rh and 203Tl were chosen as interna1 standards. The conditionsThe preconcentration and determination of gold and silver in twenty plants from the copper mining area by ICP-MS was described. The plant samples were decomposed by dry-ashing and aqua regia. 107Ag, 109Ag and 197Au were chosen as determining isotopes and 103Rh and 203Tl were chosen as interna1 standards. The conditions of sample digestion were elected and the interferences on instrument measurement were eliminated through the experiments. The detection limits of method were 0.048 and 1.06 ng·g-1 for Au and Ag. The precisions(n=5) were between 0.85% and 9.05% RSD, and the recoveries were between93.6%～101.6%(Au, Ag). The method is sensitive quick,simple and has been applied to the analysis of gold and silver in plants from the copper mining area. Under the given analytical conditions, the results showed that the contents of the Au and Ag varied in these diferent plants, the ranging between 0.181～0.99 ng·g-1 for Au and 280～2 150 ng·g-1 for Ag respectively. The geochemical anomalies on Ag were discovered in Pteris,Dicranopteris pedata and Bolbitis heteroclita, which can be regarded as prospecting effective indicator plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1387 (2012)
Determination of Heavy Metals in Dominant Plant Species in Vanadium/Titanium Mine Area by Microwave Digestion-ICP-AES
YANG Gang, YUAN Da-gang, ZHONG Gui-jiang, and WU Jun
Ten kinds of dominant plants in Vanadium/Titanium mine area were collected, the contents of heavy metals including Pb, Zn, Cu, Cr, Cd and Ti of which aboveground and underground parts were determined by ICP-AES using microwave digestion, respectively. All samples of the plants were digested with HNO3-H2O2 system. The rTen kinds of dominant plants in Vanadium/Titanium mine area were collected, the contents of heavy metals including Pb, Zn, Cu, Cr, Cd and Ti of which aboveground and underground parts were determined by ICP-AES using microwave digestion, respectively. All samples of the plants were digested with HNO3-H2O2 system. The relative standard deviation was less than 5% for all the elements, and the recoveries were 92.90%～103.85% by adding standard recovery experiment. This method was simple, sensitive and precise and can perform simultaneous multi-elements determination compared with conventional method of the plants determination, which could satisfy the sample examination request and provide scientific rationale for determining inorganic elements of plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1391 (2012)
Preconcentration of Ultra-Trace Germanium in Water Samples with Nano-Sized TiO2 Colloid and Determination by HGAFS with Colloid Sampling
QIAN Sha-hua, LU Min, and ZHANG Xu
A novel method for preconcentration of ultra-trace germanium and determination by hydride generation atomic fluorescence spectrometry (HGAFS) was presented in this work. When the pH values of solution were 6.0～8.0, the adsorption efficiency of nano-sized TiO2 colloid for germanium was 97.0%～99.0% in a short time. Nano-A novel method for preconcentration of ultra-trace germanium and determination by hydride generation atomic fluorescence spectrometry (HGAFS) was presented in this work. When the pH values of solution were 6.0～8.0, the adsorption efficiency of nano-sized TiO2 colloid for germanium was 97.0%～99.0% in a short time. Nano-sized TiO2 colloid was used to concentrate the ultra-trace germanium in water sample due to its high absorption capacity. After centrifugation, the supernatant fluid was removed. The sediment which contained the concentrated Ge(Ⅳ) was inverted to colloid by adding HCl of certain concentration. Ge(Ⅳ) in colloid was directly determined by HGAFS. The proposed method possesses low detection limit (3σ) (0.060 μg·L-1) and good precision (the relative standard deviation (RSD) is 2.0%, n=6). The method is was also quite simple and time saving (without any filtration and desorption process). Satisfactory results were obtained when applying this method to the determination of ultra-trace germanium in water samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1397 (2012)
Determination of Selenium in Plant Samples by Hydride Generation Atomic Fluorescence Spectrometry
GOU Ti-zhong, TANG Wen-hua, ZHANG Wen-hua, LIU Shao-you, and WU Lin-dong
A method was developed by hydride generation atomic fluorescence spectrometry （HG-AFS）for the determination of selenium in plant samples. Effects of reagent and pre-reduction method on the fluorescence intensity of selenium were studied. The influence of coexisting foreign ions on the determination of selenium was alsoA method was developed by hydride generation atomic fluorescence spectrometry （HG-AFS）for the determination of selenium in plant samples. Effects of reagent and pre-reduction method on the fluorescence intensity of selenium were studied. The influence of coexisting foreign ions on the determination of selenium was also investigated. Under the optimized digestive and experimental conditions, the linear regression equation was I=139.98ｃ+27.71 for Se. The linear range, the correlation coefficient, and the detection limit of Se was 0～10 ng·mL-1, 1.000 0, and 1.45 ng·g-1 respectively. The recovery of Se （98.9%～101%, mean=100%) was determined through the use of standard reference material. The relative standard deviation for nine replicate analyses was 0.73% for Se content in shrub leaves. This method was verified by analyzing the national reference material（GSV-1）and the found value was in good agreement with the certified value. The proposed method that was successfully used for the determination of Se in plant samples has the advantages of simple operation, low cost, and high efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1401 (2012)
Preparation of Sub-Standard Samples and XRF Analytical Method of Powder Non-Metallic Minerals
KONG Qin, CHEN Lei, and WANG Ling
In order to solve the problem that standard samples of non-metallic minerals are not satisfactory in practical work by X-ray fluorescence spectrometer (XRF) analysis with pressed powder pellet, a method was studied how to make sub-standard samples according to standard samples of non-metallic minerals and to determine In order to solve the problem that standard samples of non-metallic minerals are not satisfactory in practical work by X-ray fluorescence spectrometer (XRF) analysis with pressed powder pellet, a method was studied how to make sub-standard samples according to standard samples of non-metallic minerals and to determine how they can adapt to analysis of mineral powder samples, taking the K-feldspar ore in Ebian-Wudu, Sichuan as an example. Based on the characteristic analysis of K-feldspar ore and the standard samples by X-ray diffraction (XRD) and chemical methods, combined with the principle of the same or similar between the sub-standard samples and unknown samples, the experiment developed the method of preparation of sub-standard samples: both of the two samples above mentioned should have the same kind of minerals and the similar chemical components, adapt mineral processing, and benefit making working curve. Under the optimum experimental conditions, a method for determination of SiO2, Al2O3, Fe2O3, TiO2, CaO, MgO, K2O and Na2O of K-feldspar ore by XRF was established. The determination results are in good agreement with classical chemical methods, which indicates that this method was accurate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1405 (2012)
Research on the Application of Improved M-P Neural Network to the Determination of Lead and Zinc Ore Element Contents by Energy Disperse X-Ray Fluorescence Analysis
LI Fei, GE Liang-quan, ZHANG Qing-xian, GU Yi, WAN Zhi-xiong, and LI Wang-yan
Because of different constraints (such as different kinds of measurable elements, characteristic X-ray energy, changes in matrix composition, etc.), usually it’s not easy to get accurate information of elements, resulting in mistakes in later data analysis of energy disperse X-ray fluorescence measurement. The method iBecause of different constraints (such as different kinds of measurable elements, characteristic X-ray energy, changes in matrix composition, etc.), usually it’s not easy to get accurate information of elements, resulting in mistakes in later data analysis of energy disperse X-ray fluorescence measurement. The method is based on McCulloch-Pitts neural network (M-P neural network), according to matrix effect, to establish a new neural network model for quantitative forecasting of Zn by taking the data of X-ray fluorescence measurements of Cu, Fe, Pb, etc in lead-zinc mine in western Tianshan as the training sample. The relative error between predicted value and measured value is less than 5%. This method can be more accurate and rapid for X-ray fluorescence; it provides a new approach to correcting information of X-ray fluorescence..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1410 (2012)
EDXRF Study on the Chemical Composition and Raw Material Recipe of Jindezhen Porcelains in the Five Dynasties
ZHANG Mao-lin, ZHOU Jian, LI Qi-jiang, WU Jun-ming, and GAN Ke
Early crafts of porcelain making in Jindezhen were an important issue in ceramic history of China. The chemical composition of white porcelain and celadon samples excavated from Xianghu Kiln in the Five Dynasties was analyzed using energy dispersive X-ray fluorescence (EDXRF). Raw material recipes of the samples were dEarly crafts of porcelain making in Jindezhen were an important issue in ceramic history of China. The chemical composition of white porcelain and celadon samples excavated from Xianghu Kiln in the Five Dynasties was analyzed using energy dispersive X-ray fluorescence (EDXRF). Raw material recipes of the samples were discussed. The results showed that white porcelain bodies of Xianghu Kiln in the Five Dynasties were made from porcelain stone, while celadon bodies were made from porcelain stone and Zijin clay. Glaze ash and glaze stone were both used in the formula of white porcelain and celadon glaze, and the amount of glaze ash in the celadon was higher than that in the white porcelain samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1413 (2012)
Biomimetic Mineralization of Rod-Like Cellulose Nano-Whiskers and Spectrum Analysis
QU Ping, WANG Xuan, CUI Xiao-xia, and ZHANG Li-ping
Cellulose nano-whiskers/nano-hydroxyapatite composite was prepared with biomimetic mineralization using rod-like cellulose nano-whiskers as template. The cellulose nano-whiskers and cellulose nano-whiskers /nano-hydroxyapatite composite were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPCellulose nano-whiskers/nano-hydroxyapatite composite was prepared with biomimetic mineralization using rod-like cellulose nano-whiskers as template. The cellulose nano-whiskers and cellulose nano-whiskers /nano-hydroxyapatite composite were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy dispersive analysis of X-rays (SEM-EDXA). Variation and distribution of carbon, oxygen, calcium, and phosphorus in the composites were studied. The morphologies and growth mechanism of nano-hydroxyapatite were analyzed. The results showed that nano-hydroxyapatite was formed on the surface of cellulose nano-whiskers; the carbon-oxygen ratio of cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite was 1.81 and 1.54, respectively; the calcium-phosphorus ratio of the composite was 1.70. The nucleation of nano-hydroxyapatite was around the hydroxyl groups of cellulose nano-whiskers. It is suggested that there is coordination between the hydroxyl groups of cellulose nano-whiskers and calcium ions of nano-hydroxyapatite. The nano-hydroxyapatite can distribute in the matrix of cellulose nano-whiskers. From the atomic force microscope (AFM) images, we can see that the diameter of the spherical nano-hydroxyapatite particles was about 20 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1418 (2012)
Study of the Calibration Model of Different Pathlength Spectra in Near Infrared Noninvasive Biochemical Sensing
GAO Hong-zhi, LU Qi-peng, and DING Hai-quan
The spectral subtraction approach with different flow blood volume in near infrared noninvasive biochemical sensing can eliminate human tissue background interference, but at the same time the pathlength of subtracted spectrum is unknown. Thus, the model will be insufficiently effective if established directly with patThe spectral subtraction approach with different flow blood volume in near infrared noninvasive biochemical sensing can eliminate human tissue background interference, but at the same time the pathlength of subtracted spectrum is unknown. Thus, the model will be insufficiently effective if established directly with pathlength-unknown spectra, which is a big problem for subtracted blood volume spectrometry. In the present paper, a simulated experiment was designed to simulate this issue. The orthogonal signal correction method was proposed to eliminate the influence brought by pathlength. Compared with the PLS model before and after orthogonal signal correction, the root mean square error of cross validation (RMSECV) was from 90.17 mg·dL-1 down to 31.62 mg·dL-1, and the correlation coefficient was improved from 0.978 7 to 0.996 8. The experimental results show that using the orthogonal signal correction method can effectively restrain the interference information of pathlength, and improve the prediction precision of calibration model. The conclusion in this paper sets the stage for the practical application of the spectral subtraction approach with different flow blood volume..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1423 (2012)
The Melioration on Spectra Response Heterogeneity of Hadamard Transform Spectral Imager
LIU Cai-fang, HU Bing-liang, WEI Ru-yi, and YAN Peng
Hadamard transform optics has been developed in the past decades. It has been used in distinguishing targets, detecting feeble signals and so on. Hadamard transform spectral imager (HTSI), based on Digital Micro-Mirror Device, is a new dispersion spectral imager. HTSI has been developed in our laboratory. The spectral Hadamard transform optics has been developed in the past decades. It has been used in distinguishing targets, detecting feeble signals and so on. Hadamard transform spectral imager (HTSI), based on Digital Micro-Mirror Device, is a new dispersion spectral imager. HTSI has been developed in our laboratory. The spectral heterogeneity of encoded image captured by HTSI has been researched according to spectrum calibration in this paper. Relative and absolute spectrum emittance calibration algorithms have been proposed first time on HTSI to meliorate the spectrum heterogeneity. It aims at the problem that the accuracy of recovered spectrum is depressed by the heterogeneity noise and disorder encoding spectrum in spectral image. Simulation and experiment result have demonstrated that the meliorated spectral curve is close to the standard spectrum, and the variance of the recovered spectrum ranges from 2.4% to 4.2% with regard to the spectral image of 7 waves. This is fully satisfied for the requirement of laboratory and projects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1427 (2012)
Temperature Compensation for Portable Vis/NIR Spectrometer Measurement of Apple Fruit Soluble Solids Contents
WANG Jia-hua, QI Shu-ye, TANG Zhi-hui, JIA Shou-xing, and LI Yong-yu
Visible (Vis)/near infrared (NIR) spectroscopy has been used successfully to measure soluble solids content (SSC) in fruit. However, for practical implementation, the NIR technique needs to be able to compensate for fruit temperature fluctuations, as it was observed that the sample temperature affects the NIR spectrum.Visible (Vis)/near infrared (NIR) spectroscopy has been used successfully to measure soluble solids content (SSC) in fruit. However, for practical implementation, the NIR technique needs to be able to compensate for fruit temperature fluctuations, as it was observed that the sample temperature affects the NIR spectrum. A portable Vis / NIR spectrometer was used to collect diffused transmittance spectra of apples at different temperatures (0～30 ℃). The spectral data of apple at 20 ℃ was used to develop a norm partial least squares (PLS) model. Slope/ bias technique was found to well suits to control the accuracy of the calibration model for SSC concerning temperature fluctuations. The correctional PLS models were used to predict the SSC of apple at 0, 10 and 30 ℃, respectively. The correctional method was found to perform well with Q values of 0.810, 0.822 and 0.802, respectively. When no precautions are taken, the Q value on the SSC may be as small as 0.525～0.680. The results obtained highlight the potential of portable Vis/NIR instruments for assessing internal quality of fruits on site under varying weather conditions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1431 (2012)
A Soft Discretization Method of Celestial Spectrum Characteristic Line Based on Fuzzy C-Means Clustering
ZHANG Ji-fu, LI Xin, and YANG Hai-feng
Discretization of continuous numerical attribute is one of the important research works in the preprocessing of celestial spectrum data. For characteristic line of celestial spectrum, a soft discretization algorithm is presented by using improved fuzzy C-means clustering. Firstly, candidate fuzzy clustering centers of Discretization of continuous numerical attribute is one of the important research works in the preprocessing of celestial spectrum data. For characteristic line of celestial spectrum, a soft discretization algorithm is presented by using improved fuzzy C-means clustering. Firstly, candidate fuzzy clustering centers of characteristic line are chosen by using density values of sample data, so that its anti-noise ability is improved. Secondly, parameters in the fuzzy clustering are dynamically adjusted by taking compatibility of decision table as criteria, so that optimal discretization effect of the characteristic line is achieved. In the end, experimental results effectively validate that the algorithm has higher correct recognition rate of the algorithm by using three SDSS celestial spectrum data sets of high-redshift quasars, late-type star and quasars..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1435 (2012)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1 (2012)
Research Articles
Indirect Determination of Iodine with Methyl Isobutyl Ketone (MIBK) Extraction by Atomic Fluorescence Spectrometer
LU Jian-ping, GENG Guo-xing, LU Zhi-yong, and TANG Yan-kui
In this paper, a new method was developed for indirect determination of iodine with methyl isobutyl ketone (MIBK) extraction by atomic fluorescence spectrometer (AFS). Based upon the complex, which can be extacted perfectly by MIBK, formed between I- and Hg2+ in 0.1 mol·L-1 of nitric acid, indirectly measuring theIn this paper, a new method was developed for indirect determination of iodine with methyl isobutyl ketone (MIBK) extraction by atomic fluorescence spectrometer (AFS). Based upon the complex, which can be extacted perfectly by MIBK, formed between I- and Hg2+ in 0.1 mol·L-1 of nitric acid, indirectly measuring the iodine in organic phase becomes possible. The effects of extraction conditions and other influence factors were investigated. Under the optimized experimental conditions, the results showed that the linearity between its absorbance and the concentration of iodine was 0～12 μg·L-1, the detection limit is 0.14 μg·L-1, and the relative standard deviation is 3.3%. The method has been applied to the determination of iodine in eggs, and the recoveries are in the range of 101.8%～110.4%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 5, 1394 (2012)
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