Journals >Spectroscopy and Spectral Analysis
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2010
Volume: 30 Issue 5
62 Article(s)
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Research Article
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1 (2010)
Study on TPS434 Infrared Detector at Low Temperature and Magnetic Field
FAN Jie, SONG Xiao-hui, and ZHANG Dian-lin
The response of a commercial thermopile TPS434 to IR light as a function of temperature between 280 and 10 K, chopper frequency between 0.1 and 100 Hz, and magnetic field between 0 and 6T was measured in order to investigate its suitability for THz detection. The data show that the sensitivity of TPS434 decreases with The response of a commercial thermopile TPS434 to IR light as a function of temperature between 280 and 10 K, chopper frequency between 0.1 and 100 Hz, and magnetic field between 0 and 6T was measured in order to investigate its suitability for THz detection. The data show that the sensitivity of TPS434 decreases with the decrease in temperature or the increase in chopper frequency. The relaxation time of TPS434 at low temperature is smaller than that at room temperature, which can improve the system response time. Thermopile’s thermoelectromotive force increases linearly under low temperature with the magnetic field increasing, but the influence of the magnetic field can be deducted through the linear fitting to the measurement result. The possibility of using the device as a THz detector was analyzed by estimating the equivalent noise power (NEP) and the smallest detected power Pmin..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1153 (2010)
Rotational and Vibrational State Distributions of CsH in the Reactions of Cs(62D5/2) with H2
WANG Da-gui, ZHOU Dong-dong, WANG Xue-yan, MU Ni-sai, DAI Kang, and SHEN Yi-fan
The nascent quantum state distributions of the CsH product resulting from the reaction Cs(6D5/2) with H2 were determined using a laser pump-probe technique in a five-arm crossed heat-pipe oven. Cs-H2 mixture was irradiated with pulses of 885.4 nm radiation from a OPO laser, populating 6D5/2 state by two-photon absosptiThe nascent quantum state distributions of the CsH product resulting from the reaction Cs(6D5/2) with H2 were determined using a laser pump-probe technique in a five-arm crossed heat-pipe oven. Cs-H2 mixture was irradiated with pulses of 885.4 nm radiation from a OPO laser, populating 6D5/2 state by two-photon absosption. Laser induced fluorescence was used to detect CsH molecules directly at the collision volume by scanning pulse tunable dye laser over X 1Σ＋(ｖ″, Ｊ″)→Ａ １Σ＋(ｖ′, Ｊ′＝Ｊ″±１) absorption line. The vibration bands (v″=0, v′=6) and (v″=1, v′=9) were chosen. For the investigated reaction, the nascent CsH product molecules were found to populate the lowest two vibrational (v″=0, 1) levels of the ground electronic state but could not be detected in any higher vibrational state. Rotational distributions of CsH products obtained for v″=0 and 1 states appear to be monomodal , peaking in J=6-8. The rotational population profile is roughly consistent with a statistical distribution at the system temperature. A plot of logarithm of relative population of states J divided by the degeneracy factor (2J+1) against J(J+1) was yielded. The linearity of the plot establishes the Boltzmann form for rotational distributions of both the v″=0 and 1. The rotational temperatures are (458±20) K and (447±18) K for v=0 and 1, respectively. The nascent CsH rotational temperatures were found to be slightly below the cell temperature. The relative vibrational population was determined to be 0.527 and 0.473. The average vibrational and rotational energy release can be computed. The relative fractions 〈fV〉, 〈fR〉 and 〈fT〉 of average energy disposal were derived as 0.25, 0.10 and 0.65 respectively, having a major translation energy release. All of the above results support the assumption that the Cs(6 2D5/2)-H2 reaction occurs primarily in a collinear geometry by a harpoon mechanism but not an insertion..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1157 (2010)
Research on High Resolution Spectrum Measurements of Methane at 1.65 μm
WANG Huan, CAO Zhen-song, WANG Zhu-qing, WANG Liu-san, GAO Wei, ZHANG Wei-jun, and GAO Xiao-ming
The high resolution spectrum of methane was obtained around 1.65 μm using a tunable DFB diode laser with a long adjustable optical path white·cell (46.36-1 158.90 m) at room temperature through the direct absorption technique. The typical line width of the DFB diode laser is about 10 MHz and the wavelength of DFB The high resolution spectrum of methane was obtained around 1.65 μm using a tunable DFB diode laser with a long adjustable optical path white·cell (46.36-1 158.90 m) at room temperature through the direct absorption technique. The typical line width of the DFB diode laser is about 10 MHz and the wavelength of DFB laser was calibrated by an optical wavemeter. A total of 259 new absorption lines were studied from 6 043.00 to 6 053.72 cm-1 at five different pressures and optical lengths. All the data were fitted by Gaussian profile, the line intensities, positions and the percent of the statistical standard deviation (σS/S)% of the line intensities were obtained, and the absorption lines which are hard to be distinguished were analyzed in this paper. The weakest absorption line is 4.3×10－27cm-1·(mol·cm-2)-1, while the lines stronger than 3.0×10-24 cm-1·(mol·cm-2)-1 were ignored for their saturated absorption due to the long absorption optical length(788-1 000 m). Meantime, the spectrum shows the abundance of methane weak lines and its extremely complex structure around 1.65 μm. All the lines cannot be found in HITRAN2004 database, and as to our knowledge, they were not reported before by other papers..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1161 (2010)
Spectroscopic Investigation of the Argon Plasma Discharge in Quartz Capillary at Atmospheric Pressure
HUANG Wen-tong, LI Shou-zhe, GUO Qing-chao, ZHANG Jia-liang, WANG De-zhen, and MA Teng-cai
An arc plasma discharge with a long length of 20 cm was generated in a quartz capillary between two hollow needle electrodes in argon at atmospheric pressure with use of the sinusoidal power supply operating at 45 kHz, which was characterized by a very high electron density. The spectroscopic method of optical emissionAn arc plasma discharge with a long length of 20 cm was generated in a quartz capillary between two hollow needle electrodes in argon at atmospheric pressure with use of the sinusoidal power supply operating at 45 kHz, which was characterized by a very high electron density. The spectroscopic method of optical emission was employed to diagnose the characteristic parameters of the arc plasma discharge in the quartz capillary. The gas temperature was determined by simulating the OH A-X(0, 0) vibrational band around 300 nm and comparison with measured spectrum by means of optical emission spectroscopy. Furthermore, the electron density was measured by means of Stark broadening of the profile of Hβ at 486.1 nm. The electron temperature was determined using a Boltzmann plot method. The experiment results show that in the argon arc plasma discharge generated in the quartz capillary at atmospheric pressure, the gas temperature of plasma is about (1 100±50)K, the electron density at the gas temperature of 1 100 K is approximately 1014 cm-3, and the corresponding electron temperature is (14 515±500)K. This work has accumulated some significant experimental parameters for the treatment of inner surface of large length-to-radius-ratio insulated dielectric tube using plasma, and the results are of great importance to the applications of this type of atmospheric-pressure plasma discharge..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1167 (2010)
Preparation and Spectral Characterization of Lumogen Coatings for UV-Responsive CCD Image Sensors
ZHANG Da-wei, TIAN Xin, HUANG Yuan-shen, NI Zheng-ji, and ZHUANG Song-lin
Traditional charge-coupled devices (usually front-illuminated CCDs) and complementary metal oxide semiconductor (CMOS) have lower response in ultraviolet region particularly. The reason is that polysilicon gate material absorbs the ultraviolet radiation highly, which leads to a barricade of the radiation penetrating thTraditional charge-coupled devices (usually front-illuminated CCDs) and complementary metal oxide semiconductor (CMOS) have lower response in ultraviolet region particularly. The reason is that polysilicon gate material absorbs the ultraviolet radiation highly, which leads to a barricade of the radiation penetrating the gate to the channel of CCD. To enhance the detective responsibility of CCD in the ultraviolet region, a feasible method is to coat the surface of CCD polysilicon gate with a thin film. The thin film should have the ability of converting the ultraviolet to visible in order to enable the UV radiation to “penetrate” the polysilicon gate. An organic coating to convert the UV radiation to visible has been developed in the present paper. Lumogen thin films were deposited on fused silica substrates by vacuum evaporation of an organic dye called Lumogen Yellow S0790. Analysis of organic functional groups was used to study the luminescence mechanism of Lumogen. The optical constants of coatings were calculated by spectroscopic ellipsometry. The results indicate that Lumogen exhibits photoluminescence continuously owing to four kinds of double bonds in each Lumogen molecule. The refractive index of Lumogen film was ～1.3, which indicates that this film could be considered an antireflection coating. Finally, the spectral properties of Lumogen coatings were characterized by transmission, absorption, photoluminescence emission, and excitation spectra. It is showed that these coatings were transmitted well in visible region (λ＞470 nm), and emitted a yellowish green glow centered at ～523 nm together with a wide excitation spectrum field from 240 nm to 490 nm. The synthesis shows that Lumogen coatings match accurately with the detected spectrum of conventional silicon-based image sensors, which makes this kind of thin films an ultraviolet responsive coating for sensors..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1171 (2010)
Enhancing Effect of Sample Additive on Laser-Induced Plasma Radiation
ZHANG Lin-jing, CHEN Jin-zhong, YANG Shao-peng, WEI Yan-hong, and GUO Qing-lin
In order to improve the radiation characteristic of laser-induced plasma, with the national standard soil taken as the target sample, a laser spectrum analytical system which composed of a high-energy neodymium glass laser, a multifunctional and compact integrated spectrometer, and a CCD detector was used to detect theIn order to improve the radiation characteristic of laser-induced plasma, with the national standard soil taken as the target sample, a laser spectrum analytical system which composed of a high-energy neodymium glass laser, a multifunctional and compact integrated spectrometer, and a CCD detector was used to detect the influence of the NaCl sample additive on the laser plasma radiation intensity. The electron temperature and the electron density of the plasmas were also calculated from the lines intensity and stark broadening of emission spectral line respectively. The experimental results indicated that with the increase in the NaCl additive, the spectral intensity, signal-to-background ratio, the electron temperature, and the electron density all went up firstly and then down. When 15% NaCl was added, the radiation intensity of the plasma reached the maximum value, the spectral lines intensity of element Mn, K, Fe, and Ti increased by 39.2%, 42.5%, 53.9% and 33.8% compared to that without additive respectively, the spectral signal-to-background ratio increased by 64.4%, 84.3%, 44.55% and 58.2% respectively, while the electron temperature and the electron density of the plasmas were heightened by 0.17 times and 0.36 times respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1175 (2010)
Influence of the Amount of H2O on the Emission Spectra of Tb Doped SiO2Xerogels
PAN Jing, HU Xiao-yun, LIU Guo-jing, ZHANG De-kai, and FAN Jun
Tb-doped luminescent SiO2 xerogel was prepared by the sol-gel technique. FTIR was used to measure the microstructure of the luminescent materials. The luminescence properties were characterized by F-7000 UV-visible fluorescence spectrophotometer. The effects of the molar ratio of H2O on the fluorescence and phosphorescTb-doped luminescent SiO2 xerogel was prepared by the sol-gel technique. FTIR was used to measure the microstructure of the luminescent materials. The luminescence properties were characterized by F-7000 UV-visible fluorescence spectrophotometer. The effects of the molar ratio of H2O on the fluorescence and phosphorescence intensity and phosphorescence lifetime of the sample were mainly investigated. The results showed that for the Tb3+ doped xerogels, the sample of 1∶4∶4 annealed at 650 ℃ reaches the maximum intensity, the sample of 1∶4∶5 annealed at 750 ℃ reaches the maximum, the sample of 1∶4∶6 annealed at 850 ℃ is the strongest. With increasing the amount of water, the luminous intensity of the samples annealed at 750 ℃ was first weakened, then enhanced and finally weakened. It was shown that the luminous intensity of samples is related to the molar ratio of aqueous solutions and annealing temperature, whose influence on the luminous intensity formed a competitive mechanism. Phosphorescence was observed at the same time, illustrating the existence of defects in the matrix space, and that the influence of water on the intensity is the same as that of fluorescence. In addition, with the increase in the molar ratio of aqueous solutions, the amount of defect gradually changed and resulted in a change in the luminescence decay time..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1179 (2010)
Two-Dimensional Synchronous Correlation Spectroscopy for Probing Fluorescence Energy Transfer
HUANG Kun, CHEN Jing, LIU Shao-xuan, GAO Xiu-xiang, PAN Qing-hua, ZHANG Cheng-feng, LIU Yu-hai, XIA Jin-ming, QI Jian1, XU Yi-zhuang, and WU Jin-guang
In the present paper, the authors developed a new approach by constructing two-dimensional (2D) UV-Vis/fluorescence heterogeneous synchronous spectrum based on the orthogonal sample design scheme (OSD) developed in our previous works to characterize energy transfer among different lanthanide ions during the luminescencIn the present paper, the authors developed a new approach by constructing two-dimensional (2D) UV-Vis/fluorescence heterogeneous synchronous spectrum based on the orthogonal sample design scheme (OSD) developed in our previous works to characterize energy transfer among different lanthanide ions during the luminescence process. The authors use the EuCl3-NdCl3 system as an example. The preliminary experimental results on the 2D synchronous spectra of EuCl3-NdCl3 mixture solutions have demonstrated that cross peaks can be observed among the UV-Vis absorption bands from Nd3+ and fluorescence emission bands from Eu3+. The cross peaks in the 2D synchronous spectra of EuCl3-NdCl3 mixture solutions manifested the interaction between the fluorescence emission from Eu3+ and UV-Vis absorbance from Nd3+, and therefore gives out experimental evidences for the occurrence of energy transfer between Eu3+ and Nd3+ ions. The cross peaks are not from the interaction between the solvent, water, and the solute, Eu3+ or Nd3+ ions. Mathematical analysis performed on 2D synchronous spectra using variable concentration as an external perturbation shows that the orthogonal sample design scheme is indispensable in removing the interfering cross peaks in 2D synchronous spectra. In fact, if the authors detect, respectively, the fluorescence emission spectra of pure Eu3+ solutions and the UV-Vis absorbance spectra of pure Nd3+ solutions, then use these spectra data to construct a series of synthesized spectra of an assumed mixture solution in which Eu3+ and Nd3+ are not mixed together, because Eu3+ and Nd3+ ions are spatially separated, there are no intermolecular interactions that should have occurred. Therefore, there are no cross-peaks that can be observed in the comparative 2D synchronous spectra. The cross peaks in 2D synchronous correlation spectra gives out a new approach to characterizing energy transfer among different lanthanide ions during the luminescence process..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1184 (2010)
Study on Estimation of Radiation Dose Using FTIR in Mice Thymus
WU Wen-an, WANG Jian-sheng, ZHANG Jia, MO Fei, WANG Si-cen, ZHOU Su-na, ZHANG Ming-xin, XU Yi-zhuang, SHI Jing-sen, and WU Jin-guang
Fourier transform infrared spectroscopy (FTIR) was applied to study the biochemical changes in the radiation damaged mouse thymus which increased with radiation dose and provided a new method for the estimation of the radiation dose of radiation damaged patients. The results demonstrated that with the dose increasing, Fourier transform infrared spectroscopy (FTIR) was applied to study the biochemical changes in the radiation damaged mouse thymus which increased with radiation dose and provided a new method for the estimation of the radiation dose of radiation damaged patients. The results demonstrated that with the dose increasing, the peak positions like 1 550, 1 400, 1 400 and 1 640 cm-1 at the dose of 2, 3 and 5 Gy showed some difference, and there was obvious variance in the intensity: (1) The intensity ratio of 1 085 to 1 236 cm-1 related to nucleic acid tended to decrease. (2) The intensity ratio of 1 640/1 550 decreased. (3) The intensity at 2 958, 2 925, 1 460 and 1 400 cm-1 showed no significant difference. The results suggest that it may be possible for FTIR to become an effective method to estimate the radiation dose in clinic..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1189 (2010)
Ionization Energies and Infrared Spectra Studies of Histidine Using Density Functional Theory
HU Qiong, WANG Guo-ying, LIU Gang, OU Jia-ming, and WANG Rui-li
Histidines provide axial ligands to the primary electron donors in photosynthetic reaction centers (RCs) and play an important role in the protein environments of these donors. In this paper the authors present a systematic study of ionization energies and vibrational properties of histidine using hybrid density functiHistidines provide axial ligands to the primary electron donors in photosynthetic reaction centers (RCs) and play an important role in the protein environments of these donors. In this paper the authors present a systematic study of ionization energies and vibrational properties of histidine using hybrid density functional theory (DFT). All calculations were undertaken by using B3LYP method in combination with four basis sets: 6-31G(d), 6-31G(df, p), 6-31+G(d) and 6-311+G(2d,2p) with the aim to investigate how the basis sets influence the calculation results. To investigate solvent effects and gain a detailed understanding of marker bands of histidine, the ionization energies of histidine and the vibrational frequencies of histidine which are unlabeled and 13C, 15N, and 2H labeled in the gas phase, CCl4, protein environment, THF and water solution, which span a wide range of dielectric constant, were also calculated. Our results showed that: (1) The main geometry parameters of histidine were impacted by basis sets and mediums, and C2—N3 and N3—C4 bond of imidazole ring of histidine side chain display the maximum bond lengths in the gas phase; (2) single point energies and frequencies calculated were decreased while ionization energies increased with the increasing level of basis sets and diffuse function applied in the same solvent; (3) with the same computational method, the higher the dielectric constant of the solvent used, the lower the ionization energy and vibrational frequency and the higher the intensity obtained. In addition, calculated ionization energy in the gas phase and marker bands of histidine as well as frequency shift upon 13C and 15N labeling at the computationally more expensive 6-311+G(2d,2p) level are in good agreement with experimental observations available in literatures. All calculations indicated that the results calculated by using higher level basis set with diffuse function were more accurate and closer to the experimental value. In conclusion, the results provide useful information for the further studies of the functional and vibrational properties of chlorophyll-a ligated to histidine residue in photosynthetic reaction center..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1192 (2010)
The IR Spectroscopic Study of Hydrothermal Synthetic KTP
XIE Hao, PEI Jing-cheng, QI Li-jian, and ZHONG Zeng-qiu
In the present paper, different-generation hydrothermally grown KTP crystals were tested by the Nicolet 550 type FIR spectrometer with the reflective technique. They were studied on different crystal faces. Since the hydrothermally grown KTP crystal usually grows (100), (011) and (201) crystal faces, these faces were tIn the present paper, different-generation hydrothermally grown KTP crystals were tested by the Nicolet 550 type FIR spectrometer with the reflective technique. They were studied on different crystal faces. Since the hydrothermally grown KTP crystal usually grows (100), (011) and (201) crystal faces, these faces were tested in different-generation products, and they were tested by two spectral wave bands, 2 000-4 000 and 400-2 000 cm-1. The figures were compared with the flux-melt grown KTP crystal. In addition, making reference to the method of calculation about the consistence of OH- in quartz, the consistence of OH- in different -generation hydrothermally grown KTP crystals was estimated. In the hydrothermal grown KTP crystals, the stretching vibration of OH- shows distinct directivity characteristic. The absorption at ［100］ direction is obvious and the frequency is about 30 cm-1 higher than the flux-melt grown KTP. Each new generation weakened the consistency of OH-, which restrained the growth of the KTP crystal. Accordingly, increasing the purity of rough materials plays a very important role in improving the quality of the crystals..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1198 (2010)
Study on the Characteristic Peaks of Infrared Spectra from Ganoderma Lucidums
HE Jin-zhe, SHAO Ping, and SUN Pei-long
Infrared spectroscopy and dual-indicator sequence were used to study their IR characteristic peaks of ganoderma lucidums from different places and species. The experimental results showed that the majority of ganoderma lucidum from different places and species had the similar characteristic peaks of infrared spectra, TInfrared spectroscopy and dual-indicator sequence were used to study their IR characteristic peaks of ganoderma lucidums from different places and species. The experimental results showed that the majority of ganoderma lucidum from different places and species had the similar characteristic peaks of infrared spectra, Their common peak ratio could reach more than 91.67%, but the common peak ratio of mycelium was 52.94%-58.82%, and variant peak ratio was 29.41%-66.67%. The main variation peak was in the fingerprint regions 1 460.9-1 423.7 cm-1with ladder peaks. The IR characteristic peaks of ganoderma Lucidum obviously appear as the main characteristic peaks with the type of polysaccharide and protein bands. There was obviously a wide and strong absorption peak in 3 377.8-3 396.5 cm-1, a small acromion in 2 924.2-2 925.1 cm-1, a medium intensity absorption peak in 1 635.8-1 650.3 and 1 372.5-1 375.2 cm-1, a strong absorption bifurcate peak in 1 074.8-1 075.3 and 1 043.2-1 045.2 cm-1, a obvious weak peak in fingerprint regions 891.0-894.8 cm-1, and a medium intensity absorption peak in 563.10-574.7 cm-1..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1202 (2010)
Extending Hemicelluloses Content Calibration of Acacia Spp Using NIR to New Sites
YAO Sheng, WU Guo-feng, JIANG Yi-fei, FU Xiao-dong, Lv Hong-kun, SU Mei, and PU Jun-wen
In this research, hemicellulose contents of 78 wood meal samples of Acacia spp trees grown in Guangxi and another 33 wood meal samples of Acacia spp trees grown in Fujian were measured by wet chemistry. NIR spectra were also collected by a Bruker MPA spectrometer within 4 000-12 500 cm-1 of wavenumbers using a standardIn this research, hemicellulose contents of 78 wood meal samples of Acacia spp trees grown in Guangxi and another 33 wood meal samples of Acacia spp trees grown in Fujian were measured by wet chemistry. NIR spectra were also collected by a Bruker MPA spectrometer within 4 000-12 500 cm-1 of wavenumbers using a standard sample cup. Equations were developed using partial least squares (PLS) regression and cross validation for multivariate calibration in this study. High coefficients of determination (R2) and low root mean square errors of cross-validation (RMSECV) were obtained for hemicellulose content (R2=0.947, RMSECV=0.464) of Guangxi wood meal samples. Prediction produced high correlation coefficients between laboratory and predicted values, with R2 and RMSEP values being 0.925 and 0.455, respectively. A variable numbers of Fujian samples ranging from one to thirteen were used to enhance the Guangxi calibration so as to be widely used for routine assessment of wood chemistry. It was demonstrated that the addition of a single Fujian sample to the Guangxi calibration set was sufficient to greatly reduce predictive errors and that the inclusion of 3 Fujian samples in the Guangxi set was sufficient to give relatively stable predictive errors. The R2 is 0.904 and RMSEP is 0.759. The addition of different sets of 3 Fujian samples to the Guangxi calibration, however, caused predictive errors to vary between sets..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1206 (2010)
Analysis of Soil Humus and Components after 26 Years’ Fertilization by Infrared Spectroscopy Method
ZHANG Yu-lanm, SUN Cai-xia, CHEN Zhen-hua, LI Dong-po, LIU Xing-bin, CHEN Li-jun, WU Zhi-jie, and DU Jian-xiong
The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year’s fertilization. The result indicated that using the infrared spectroscopy method for the deterThe infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year’s fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree. After 26 years’ fertilization, the infrared spectrum shapes with different treatments are similar, but the characteristic peak intensity is obviously different, which reflects the effects of different fertilization treatments on the structure and amounts of soil humus or functional groups. Compared with no fertilization, little molecule saccharides decreased and aryl-groups increased under application of inorganic fertilizer or combined application of organic and chemical fertilizer. The effect was greater in Treatment NPK and M+NPK than in Treatment M1N and M2N. Organic and NPK fertilizer increased the development of soil and increased soil quality to a certain extent. Results showed that organic fertilization increased aromatization degree of soil humus and humus fractions distinctly. The authors could estimate soil humus evolvement of different fertilization with infrared spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1210 (2010)
Study on the Application of Ridge Regression to Near-Infrared Spectroscopy Quantitative Analysis and Optimum Wavelength Selection
ZHANG Man, LIU Xu-hua, HE Xiong-kui, ZHANG Lu-da, ZHAO Long-lian, and LI Jun-hui
In the present paper, taking 66 wheat samples for testing materials, ridge regression technology in near-infrared (NIR) spectroscopy quantitative analysis was researched. The NIR-ridge regression model for determination of protein content was established by NIR spectral data of 44 wheat samples to predict the protein cIn the present paper, taking 66 wheat samples for testing materials, ridge regression technology in near-infrared (NIR) spectroscopy quantitative analysis was researched. The NIR-ridge regression model for determination of protein content was established by NIR spectral data of 44 wheat samples to predict the protein content of the other 22 samples. The average relative error was 0.015 18 between the predictive results and Kjeldahl’s values (chemical analysis values). And the predictive results were compared with those values derived through partial least squares (PLS) method, showing that ridge regression method was deserved to be chosen for NIR spectroscopy quantitative analysis. Furthermore, in order to reduce the disturbance to predictive capacity of the quantitative analysis model resulting from irrelevant information, one effective way is to screen the wavelength information. In order to select the spectral information with more content information and stronger relativity with the composition or the nature of the samples to improve the model’s predictive accuracy, ridge regression was used to select wavelength information in this paper. The NIR-ridge regression model was established with the spectral information at 4 wavelength points, which were selected from 1 297 wavelength points, to predict the protein content of the 22 samples. The average relative error was 0.013 7 and the correlation coefficient reached 0.981 7 between the predictive results and Kjeldahl’s values. The results showed that ridge regression was able to screen the essential wavelength information from a large amount of spectral information. It not only can simplify the model and effectively reduce the disturbance resulting from collinearity information, but also has practical significance for designing special NIR analysis instrument for analyzing specific component in some special samples..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1214 (2010)
Application of FTIR Spectroscopy to the Identification of Glycyrrhiza Uralensis Fisch
SUO Jing-xia, SUN Su-qin, and WANG Wen-quan
Fourier transform infrared spectroscopy with a spectra range of 4 000-400 cm-1 was used to identify fifty nine samples of wild or cultivated Glycyrrhiza uralensis Fisch. from six different places around China. The 1D spectra and their second derivative spectra of herbal samples, the corresponding extract samples and twFourier transform infrared spectroscopy with a spectra range of 4 000-400 cm-1 was used to identify fifty nine samples of wild or cultivated Glycyrrhiza uralensis Fisch. from six different places around China. The 1D spectra and their second derivative spectra of herbal samples, the corresponding extract samples and two marker compounds (glycyrrhizic acid and liquiritin) were compared. The wide peak in 1 100-1 000 cm-1 was used to identify the components of polysaccharide; the peak at 1 318 cm-1 mainly belonged to calcium oxalate; the peaks at 1 745 and 1 386 cm-1 were used to assess the content of glycyrrhizic acid; the peaks at 1 612 and 1 512 cm-1 were the characteristic peaks of liquiritin. The intensity of characteristic peaks can represent the content of corresponding compound. The horizontal and vertical comparisons of all herbal samples showed that the characteristic peaks of wild samples were strong, and all wild samples had the similar quality; the characteristic peaks of cultivated samples were weaker than those of the wilds; the ages of glycyrrhiza had great effect on the quality of samples.
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1218 (2010)
The Enhancement of 1.5 μm Near Infrared Luminescence in Er3+and Yb3+Codoped Y2O3Nanocrystalline
MENG Qing-yu, CHEN Bao-jiu, Lv Shu-chen, UN Jiang-ting, and QU Xiu-rong
(Y0.96Er0.02Yb0.02)O3 nanocrystals of 10 and 40 nm average particle size were prepared by combustion method. And bulk materials of the same components were obtained by annealing at 1 200 ℃. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, transmission electron microscope (TEM), and scanning electron (Y0.96Er0.02Yb0.02)O3 nanocrystals of 10 and 40 nm average particle size were prepared by combustion method. And bulk materials of the same components were obtained by annealing at 1 200 ℃. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, transmission electron microscope (TEM), and scanning electron microscopy (SEM) were used to characterize the crystal structure and morphology of the samples. The upconversion emission spectra and NIR (near-infrared) emission spectra were measured, under 980 nm excitation. The research result indicates that as the particle size decreases, the upconversion red emission and NIR emission components increase in the emission spectra. This phenomenon is attributed to the large ratio of surface area to volume in nanocrystals. This characteristic makes the nanocrystals absorb more OH-, whose vibrational energy is 3 200-3 800 cm-1. The increase in the OH－ number enhances the rate of nonradiative relaxation from Er3+ 4I11/2 to 4I13/2 energy level (energy gap is 3 600 cm-1). This nonradiative relaxation process depopulates the 4I11/2 level and makes the green emission weaker. Meanwhile, this process populates the 4I13/2 level and makes the red and NIR emissions stronger. The intensity of 1.5 μm main peak is 1.6 times that of bulk materials. This result has great significance in actual applications of nanophosphors..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1224 (2010)
Study of Nondestructive and Fast Identification of Fabric Fibers Using Near Infrared Spectroscopy
YUAN Hong-fu, CHANG Rui-xue, TIAN Ling-ling, SONG Chun-feng, YUAN Xue-qin, and LI Xiao-yu
A fast and nondestructive identification method to distinguish different types of fabric fibers is proposed in the present paper. A total of 214 fabric fiber samples, including wool, cashmere, terylene, polyamide, polyurethane, silk, flax, linen, cotton, viscose, cotton-flax blending, terylene-cotton blending, and woolA fast and nondestructive identification method to distinguish different types of fabric fibers is proposed in the present paper. A total of 214 fabric fiber samples, including wool, cashmere, terylene, polyamide, polyurethane, silk, flax, linen, cotton, viscose, cotton-flax blending, terylene-cotton blending, and wool-cashmere blending, were collected from Beijing Textile Fibre Inspection Institute. They contain yarns, raw wool or cashmere, and various fabric straps with different colors and different braid patterns. Sample presentation for measuring near infrared spectra of various textile fibers was tried to reduce the impact from the ununiformity of polymorphous fabric structure. Spectral data were pretreated using multiplicative signal correction (MSC) to reduce the influence of spectral noise and baseline shift. Classification of 12 kinds of fabric fibers in various braid patterns was studied using minimum spanning tree method and soft independent modeling of class analogy (SIMCA) classification based on principal component analysis of NIR spectra. The minimum spanning tree for the spectra of total samples shows that the samples in the same type fall almost into one cluster, but there are overlaps between some two different clusters of fabric fibers with very similar chemical compositions, such as wool and cashmere. Complete discrimination between cashmere and wool has been achieved using SIMCA. The results show that nondestructive and fast identification of fabric fibers using near infrared spectral technique is potentially feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1229 (2010)
Real-Time Monitoring of Industrial Acetic Acid Production Process Using a New Type of Online NIR Analysis System
YE Hua-jun, ZHANG Xue-feng, WU Ji-ming, XIA A-lin, WANG Xin, YANG Hui-hua, and WANG Jian
The safe and real-time monitoring of the production process of acetic acid is always a key technical problem. The conventional online chromatographic analysis can’t satisfy the requirements of real-time analysis for its inherent disadvantages. A new type of on-line near-infrared analysis system has been developed for rThe safe and real-time monitoring of the production process of acetic acid is always a key technical problem. The conventional online chromatographic analysis can’t satisfy the requirements of real-time analysis for its inherent disadvantages. A new type of on-line near-infrared analysis system has been developed for real-time analysis of the concentration of each component in acetic acid reaction kettles instantly. Its features and configuration were described in detail. Both the laboratory modeling and field application results have confirmed that this system is of high stability and accuracy. The proposed system can effectively solve the key technical problems in the manufacture and ensure the safety and stability of production process of acetic acid..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1234 (2010)
Discriminant Analysis of Raw Milk Adulterated with Botanical Filling Material Using Near Infrared Spectroscopy
LI Liang, and DING Wu
In order to find out a fast measure method of adulterated milk based on near infrared spectroscopy, milk adulterated with plant butter, vegetable protein and starch was collected respectively. Using Fourier transform near infrared spectroscopy to scan the samples, the spectrum data were obtained. The samples were scannIn order to find out a fast measure method of adulterated milk based on near infrared spectroscopy, milk adulterated with plant butter, vegetable protein and starch was collected respectively. Using Fourier transform near infrared spectroscopy to scan the samples, the spectrum data were obtained. The samples were scanned in the spectral region between 4 000 and 12 000 cm-1 by FT-NIR spectrometer with an optic fiber of 2 mm path-length and an InGaAs detector. Then all data were analyzed by principal component analysis combined with Fisher line discriminant analysis (FLDA) and partial least squares (PLS). Results show that the accumulative reliabilities of the first six components were more than 99%, so the first six components were applied as FLDA inputs and the values of the type of milk were applied as the outputs. An adulterated milk qualitative discriminant model based on Fisher line discriminant analysis was developed finally. The result indicated that the accuracy of detection of calibration samples is 97.78%. The unknown test samples were tested by this model and the correct identification rate is 94.44%. Partial least square models for detecting the content of material added to raw milk were set up with good veracity. The predictive correlation coefficient (R2) of calibration sets of milk adulterated with plant butter, vegetable protein and starch are 99.08%, 99.96% and 99.39%, respectively, while the root mean square errors of cross validation (RMSECV) of the three calibration sets are 0.304%, 0.013 5% and 0.060%, respectively. The R2 of validation sets of the three kinds of adulterated milk are 98.50%, 99.94% and 98.50%, respectively, while the root mean square errors of prediction (RMSEP) of the three validation sets are 0.323%, 0.028 8% and 0.068%, respectively. All of these suggested that near infrared spectroscopy has good potential for rapid qualitative and quantitative detection of milk adulterated with botanical filling material..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1238 (2010)
Applications of Near Infrared Reflectance Spectroscopy Technique to Determination of Forage Mycotoxins
XU Qing-fang, HAN Jian-guo, YU Zhu, and YUE Wen-bin
The near infrared reflectance spectroscopy technique (NIRS) has been explored at many fields such as agriculture, food, chemical, medicine, and so on, due to its rapid, effective, non-destructive, and on-line characteristics. Fungi invasion in forage materials during processing and storage would generate mycotoxins, whThe near infrared reflectance spectroscopy technique (NIRS) has been explored at many fields such as agriculture, food, chemical, medicine, and so on, due to its rapid, effective, non-destructive, and on-line characteristics. Fungi invasion in forage materials during processing and storage would generate mycotoxins, which were harmful for people and animal through food chains. The determination of mycotoxins included the overelaborated pretreatments such as milling, extracting, chromatography and subsequent process such as enzyme linked immunosorbent assay, high performance liquid chromatography, and thin layer chromatography. The authors hope that high precision and low detection limit spectrum instrument, and software technology and calibration model of mycotoxins determination, will fast measure accurately the quality and quantity of mycotoxins, which will provide basis for reasonable process and utilization of forage and promote the application of NIRS in the safety livestock product..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1243 (2010)
Fast Discrimination of Commerical Corn Varieties Based on Near Infrared Spectra
WU Wen-jin, WANG Hong-wu, CHEN Shao-jiang, GUO Ting-ting, WANG Shou-jue, SU Qian, SUN Ming, and AN Dong
The existing methods for the discrimination of varieties of commodity corn seed are unable to process batch data and speed up identification, and very time consuming and costly. The present paper developed a new approach to the fast discrimination of varieties of commodity corn by means of near infrared spectral data. The existing methods for the discrimination of varieties of commodity corn seed are unable to process batch data and speed up identification, and very time consuming and costly. The present paper developed a new approach to the fast discrimination of varieties of commodity corn by means of near infrared spectral data. Firstly, the experiment obtained spectral data of 37 varieties of commodity corn seed with the Fourier transform near infrared spectrometer in the wavenumber range from 4 000 to 12 000 cm-1. Secondly, the original data were pretreated using statistics method of normalization in order to eliminate noise and improve the efficiency of models. Thirdly, a new way based on sample standard deviation was used to select the characteristic spectral regions, and it can search very different wavenumbers among all wavenumbers and reduce the amount of data in part. Fourthly, principal component analysis (PCA) was used to compress spectral data into several variables, and the cumulate reliabilities of the first ten components were more than 99.98％. Finally, according to the first ten components, recognition models were established based on BPR. For every 25 samples in each variety, 15 samples were randomly selected as the training set. The remaining 10 samples of the same variety were used as the first testing set, and all the 900 samples of the other varieties were used as the second testing set. Calculation results showed that the average correctness recognition rate of the 37 varieties of corn seed was 94.3%. Testing results indicate that the discrimination method had higher precision than the discrimination of various kinds of commodity corn seed. In short, it is feasible to discriminate various varieties of commodity corn seed based on near infrared spectroscopy and BPR..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1248 (2010)
Study of Rotator Phase and Phase Transition of Short-Chain Alkane by Means of Raman Spectroscopy
CHEN Yi-ting, JIN Yuan-hao, and DU Wei-min*
Raman spectroscopy was used to investigate the phase transition of n-hexacosane for real-time cooling run. In the cooling process, the n-hexacosane experienced the melt phase→rotator phase→monoclinic crystal phase transition. The changes in band intensity and frequency in the CH2 bending, CH2 twisting, skeletal C—C strRaman spectroscopy was used to investigate the phase transition of n-hexacosane for real-time cooling run. In the cooling process, the n-hexacosane experienced the melt phase→rotator phase→monoclinic crystal phase transition. The changes in band intensity and frequency in the CH2 bending, CH2 twisting, skeletal C—C stretching, and CH3 rocking regions were mainly analyzed in order to know the changing sequence and process of these vibrational modes, and to reflect the relationship between these vibrational modes and molecular structure. Besides, the changes in band intensity and frequency revealed both transitions, particularly when using band components related to gauche bonds. Our research shows that Raman spectroscopy is an effective tool to monitor the phase transition of n-alkanes or even long-chain polymers. In addition, by analyzing the Raman peaks in 800-1 500 cm-1 in the cooling process of n-hexacosane, the temperature range of rotator phase was obtained, proving that Raman spectroscopy can be used to observe the rotator phase occurring during the phase transition of paraffin..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1252 (2010)
Raman Spectrum Study on Synthesis Mechanism of Porous ZnO Microspheres Assisted with Trisodium Citrate
SHAO Zheng-zheng, ZHANG Xue-ao, WANG Xiao-feng, and CHANG Sheng-li
Raman spectrum was applied to analyze the synthesis mechanism of nanostructure porous ZnO microspheres prepared via hydrothermal method assisted with trisodium citrate. The Raman spectrum characteristics of the sample revealed that the ZnO microspheres contained Zn-citrate complex, which was the complex of citrate acidRaman spectrum was applied to analyze the synthesis mechanism of nanostructure porous ZnO microspheres prepared via hydrothermal method assisted with trisodium citrate. The Raman spectrum characteristics of the sample revealed that the ZnO microspheres contained Zn-citrate complex, which was the complex of citrate acid group and Zn2+ in the reaction solution. The complex was chemisorbed on (204) and (503) faces of the Zn(OH)2 crystallite in the reacting solution, resulting in Zn(OH)2 nanosheet from the crystallite. Large quantities of Zn(OH)2 nanosheets aggregated as porous microspheres in hydrothermal process. Zn-citrate complex chemisorbed on the nanosheet improved the thermal stability of Zn(OH)2, which means a decomposition temperature over 200 ℃. Nanostructure porous ZnO microspheres were obtained by heating Zn(OH)2 microspheres at 300 ℃ and the nanosheet structure was maintained..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1257 (2010)
A Study of Phonon Vibration Like Modes for Aggregation Structure in Silicate Melts by High Temperature Raman Spectrum
XU Pei-cang, LI Ru-bi, SHANG Tong-ming, ZHOU Jian, SUN Jian-hua, and YOU Jing-lin
Silicate melts are special fractal dimension system that is metastable state of near-way order and far-way disorder. In this paper, the size of nanometer aggregation structure and the frequences of phonon vibration like mode in the low dimension silicate series(CaO-Al2O3-SiO2 and Na2O-Al2O3-SiO2 series) synthesized viaSilicate melts are special fractal dimension system that is metastable state of near-way order and far-way disorder. In this paper, the size of nanometer aggregation structure and the frequences of phonon vibration like mode in the low dimension silicate series(CaO-Al2O3-SiO2 and Na2O-Al2O3-SiO2 series) synthesized via high temperature melting and sol gel methods were measured by means of small-angle X-ray scattering (SAXS), low wavenumber Raman spectrum(LWRS) and high temperature Raman spectrum(HTRS in situ measuring). The nanometer self-similarity aggregation structure(it’s size is about a few nm to a few tens nm) and phonic phonon vibration like modes of low temperature silicate gel, high temperature silicate melts and it’s quenching glasses phases were obtained. So a quantitative method by HTRS for measuring the aggregation size in the high temperature melts was established. The results showed that the aggregation size of the silicate melts is smaller at high temperature than at room temperature and the number of bridge oxygen in one Si—O tetrahedron in network structure units is decreasing at high temperature. This study work provides important theory and information for deliberating geochemistry characteristic, crystallization & evolution of natural magma and enhancing performance of low dimension silicate matelials..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1261 (2010)
Study on Real-Time Imaging of Single Stretched DNA Molecules by Total Internal Reflection Fluorescence Microscopy
LIN Dan-ying, LIU Xiao-chen, WANG Peng-fei, and MA Wan-yun
Total internal reflection fluorescence microscopy (TIRF) is a powerful tool for single molecule study, since only a thin layer of about 200 nanometers is excited by the evanescent wave, resulting in high sensitivity of detection and high signal-to-noise ratio of images. Molecular combing is a convenient and efficient wTotal internal reflection fluorescence microscopy (TIRF) is a powerful tool for single molecule study, since only a thin layer of about 200 nanometers is excited by the evanescent wave, resulting in high sensitivity of detection and high signal-to-noise ratio of images. Molecular combing is a convenient and efficient way to stretch DNA molecules with the help of the binding force between DNA molecule and solid surface, as well as the lateral force introduced by ambient fluid flow. In the present paper, real-time fluorescence imaging of single DNA molecules was carried out with these two techniques. Clear images of single stretched DNA were obtained, while photocleavage of DNA-YOYO-1 complex was found to be naturally avoided under TIRF imaging conditions. Photobleaching of the complexes was investigated in real-time, and was greatly reduced by synchronizing the excitation of light (laser) and the exposure of detector (ICCD). The method optimized the experimental conditions for long-lasting real-time observation and imaging of single stretched DNA molecules, so as to lay a foundation for visually studying the kinetic processes of interactions between DNA and proteins..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1266 (2010)
Excitation-Emission Fluorescence Characterization Study of the Three Phenolic Compounds
WANG Huan-bo, ZHANG Yu-jun, XIAO Xue, JIN Dan, ZHAO Nan-jing, YIN Gao-fang, GUO Li-quan, and LIU Wen-qing
The fluorescence intensity information was collected by scanning its fluorescence spectra at different excitation wavelengths. Based on its high sensitivity and selectivity, excitation-emission fluorescence can be widely used for detection of pollutants in the environment. The characterizations of the three phenolic coThe fluorescence intensity information was collected by scanning its fluorescence spectra at different excitation wavelengths. Based on its high sensitivity and selectivity, excitation-emission fluorescence can be widely used for detection of pollutants in the environment. The characterizations of the three phenolic compounds were investigated by this method, and the fluorescence peaks of phenol, m-cresol and thymol were confirmed at 272/300 nm, 274/300 nm and 276/304 nm when the excitation and emission wavelength were set in the range of 240-360 nm and 260-500 nm respectively. The excitation and emission spectra of the three phenolic compounds are very similar because of their analogical structure. The intensity of the spectrum has a good linear relationship with the concentration when the solution concentration is between 0.02 and 1.0 mg·L-1, and the limits of detection can reach at 1 μg·L-1. Results show that the three compounds can be analyzed qualitatively and quantitatively by excitation-emission fluorescence..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1271 (2010)
Research on the 3D Fluorescence Spectra Differentiation of Phytoplankton by Coiflet2 Wavelet
LIU Bao, SU Rong-guo, SONG Zhi-jie, ZHANG Fang, and WANG Xiu-lin
In the present paper, the authors utilize the wavelet base function coiflet2 (coif2) to analyze the 3D fluorescence spectra of 37 phytoplankton species belonging to 30 genera of 7 divisions, and these phytoplankton species include common species frequently causing harmful algal blooms and most predominant algal speciesIn the present paper, the authors utilize the wavelet base function coiflet2 (coif2) to analyze the 3D fluorescence spectra of 37 phytoplankton species belonging to 30 genera of 7 divisions, and these phytoplankton species include common species frequently causing harmful algal blooms and most predominant algal species in the inshore area of China Sea. After the Rayleigh and Raman scattering peaks were removed by the Delaunay triangulation interpolation, the fluorescence spectra of those phytoplankton species were transformed with the coiflet2 wavelet, and the scale vectors and the wavelet vectors were candidate for the feature spectra. Based on the testing results by Bayesian analysis, the 3rd scale vectors were the best feature segments at the division level and picked out as the fluorescence division feature spectra of those phytoplankton species, and the group of the 3rd scale vectors, the 2nd and 3rd wavelet vectors were the best feature segments at the genus level and chosen as the fluorescent genus feature spectra of those phytoplankton species. The reference spectra of those phytoplankton species at the division level and that at the genus level were obtained from these feature spectra by cluster analysis, respectively. The reference spectra base for 37 phytoplankton species was composed of 107 reference spectra at the division level and 155 ones at the genus level. Based on this reference spectra base, a fluorometric discriminating method for phytoplankton populations was established by multiple linear regression resolved by the nonnegative least squares. For 1 776 samples of single phytoplankton species, a correct discriminating rate of 97.0% at genus level and 98.1% at division level can be obtained; The correct discriminating rates are more than 92.7% at the genus level and more than 94.8% at the division level for 384 mixed samples from two phytoplankton species.
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1275 (2010)
Determination of Antibiotics Residues in the Raw Fresh Milk of Farms in the Miyun County of Beijing with Mg2+-Sensitized Metacycline Fluorescence Microscopic Imaging Technique
LIU Ying, and YANG Le
Mg2+-sensitized metacycline fluorescence microscopic imaging technique was applied to detect the raw fresh milk of four cows breeding farms in the Miyun County of Beijing based on the capillary effect of solvent on solid supports. In the presence of NH3-NH4Cl buffer solution (pH 9.99) and PVA-124, Mg2+ and metacycline Mg2+-sensitized metacycline fluorescence microscopic imaging technique was applied to detect the raw fresh milk of four cows breeding farms in the Miyun County of Beijing based on the capillary effect of solvent on solid supports. In the presence of NH3-NH4Cl buffer solution (pH 9.99) and PVA-124, Mg2+ and metacycline can form a strong fluorescence complex of 1∶1, and Mg2+-metacycline complex can form an SOR on the hydrophobic supports with the diameter of 0.93 mm and its ring belt width of 26.2 μm. By measuring the fluorescence intensity of the ring, the quantitative analysis of metacycline was achieved with the detection limit (3σ) of 8.8×10-14 mol·ring-1 (1.8×10-7 mol·L-1) and linear range of 2.2×10-13-3.6×10-12 mol·ring-1 (4.4×10-7-7.2×10-6 mol·L-1) when 0.50 μL droplet was spotted. This method has been satisfactorily applied to the determination of metacycline in the raw fresh milk samples with the recovery of 93.8%-108% and RSD less than 4.3%.
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1279 (2010)
Study on the Elements of the Fluorescence Spectra Emitted from Ethanol-Water Mixture
WU Bin, LIU Ying, HAN Cai-qin, LUO Xiao-sen, LU Jian, and NI Xiao-wu
The 236 nm UV-light was adopted to excite the 10 ethanol-water mixture samples in which the volume percent of ethanol ranges from 10% to 95%, and the Gaussian decomposition method was used to decompose the fluorescence spectra obtained above to Gaussian curves, where every Gaussian curve can be attributed to the fluoreThe 236 nm UV-light was adopted to excite the 10 ethanol-water mixture samples in which the volume percent of ethanol ranges from 10% to 95%, and the Gaussian decomposition method was used to decompose the fluorescence spectra obtained above to Gaussian curves, where every Gaussian curve can be attributed to the fluorescence emission of a certain kind of luminescent ethanol-water cluster, which is formed by the association between water molecules and ethanol molecules. It was found that every spectrum of the certain binary mixture contains 8 Gaussian elements, and the emission density and peak wavelength of each element were also obtained. The authors studied the mechanism of the fluorescence emission of the mixtures based on the structural characters of fluorescence substances and concluded that the water molecules play an important role in the fluorescence emission: they enlarge the conjugate system as the electron donors; they bridge the ethanol molecules to form 8 kinds of new clusters at the same time, and the conformation of the clusters is rings and chains composed by several rings. Through the peak wavelengths of the Gaussian elements decomposed from the certain concentration spectrum the authors got the information about the relative size of the new clusters, i.e. the clusters are bigger or show chain structures when the peak wavelength of the Gaussian curves is located at the longer positions. The emission transition energies of the 8 kinds of new clusters were also calculated. In addition, it was found that there was a certain relation between the half-width and the association situation. The research contributes to the study of ethanol-water cluster structures and their physical and chemical characteristics..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1285 (2010)
Characterization of Biocompatible CdTe/ZnTe Quantum Dots and Its Application in Cell Labeling
LIU Xia, CHEN Dan-ni, QU Jun-le, YANG Jian-tai, LUO Yong-xiang, ROY Indrajit, WANG Xiao-mei, LIN Xiao-tan, ZHONG Lei, Prasad N Paras, XU Gai-xia, and NIU Han-ben
Water-soluble CdTe/ZnTe core-shell quantum dots (QDs) coated with L-cysteine were synthesized in low-temperature aqueous-phase one-pot approach. The authors measured the spectral characteristics of QDs at different pH in various buffer solutions and under different excitation laser powers. The primary results show thatWater-soluble CdTe/ZnTe core-shell quantum dots (QDs) coated with L-cysteine were synthesized in low-temperature aqueous-phase one-pot approach. The authors measured the spectral characteristics of QDs at different pH in various buffer solutions and under different excitation laser powers. The primary results show that the absorption spectra of QDs approximately overlap and the fluorescence spectra peaks have no shift in different pH solution. The fluorescence intensity increased linearly with increasing pH. With the incubation time in borate buffer solution, the fluorescence intensity decreased a little. Under strong power laser, the QDs were photobleached rapidly. However, QDs are strongly anti-photobleaching under appropriate laser power (＜100 μW). Thus, such QDs have good biological stability and optical stability. By conjugating the QDs with transferrin protein and constructing the targeted fluorescent nanoparticles, the authors labelled the HeLa cell successfully. Photobleaching experiments in vivo show that microenvironment inside cells affect the stability and accelerate the photobleaching of QDs..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1290 (2010)
Development of Citrus Yield Prediction Model Based on Airborne Hyperspectral Imaging
YE Xu-jun, Kenshi Sakai, and HE Yong
The phenomenon of alternate bearing of fruits seriously affects the fruit yields as well as the economic benefits of orchards. The present study investigated the possibility of airborne hyperspectral images to predict the fruit yield of individual citrus trees. The hyperspectral data were first extracted from the imageThe phenomenon of alternate bearing of fruits seriously affects the fruit yields as well as the economic benefits of orchards. The present study investigated the possibility of airborne hyperspectral images to predict the fruit yield of individual citrus trees. The hyperspectral data were first extracted from the images and the predictors were determined using partial least-squares regression (PLS). The optimal number of PLS factors were identified, and they were used as inputs of citrus yield prediction models developed by means of multiple linear regression (MLR) and artificial neural network (ANN) modelling techniques. The results showed that the models based on the hyperspectral images obtained in May achieved the best prediction, and the PLS-MLR model has a better stability and consistency than the PLS-ANN model. These results proviode an important theoretical and technical foundation for the future research and development of hyperspectral imaging-based citrus production techniques..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1295 (2010)
Spectral Characters Analysis of Ground Objects in Snowmelt Period in the Northern Slope of Tianshan Mountains
FANG Shi-feng, PEI Huan, and LIU Zhi-hui
Urumqi River Basin and Juntanghu Basin, located in the northern slope of Tianshan Mountains in Xinjiang, were selected as typical study areas. With the portable field spectrometer CI700 produced by CID in the United States and from a large number of field investigations and field measurements in the snowmelt period (usUrumqi River Basin and Juntanghu Basin, located in the northern slope of Tianshan Mountains in Xinjiang, were selected as typical study areas. With the portable field spectrometer CI700 produced by CID in the United States and from a large number of field investigations and field measurements in the snowmelt period (usually starts in the end of February or the beginning of March, and goes on for many days) from 2006 to 2009, a variety of spectral curves and their variation of typical ground objects in the snowmelt period in the northern slope of Tianshan Mountains, such as snow, ice, water and soil, were obtained, and spectral characters analysis was carried out based on the collected data. The results showed that the classes of ground objects in snowmelt period are quite monotone, however, a great challenge was brought about to the quantitative remote sensing research on surface parameters in snowmelt period because of the interactive effects of the complex systems of snow-ice-water-soil, the spectral properties of typical ground objects, and their complex changes. Reflectance of soil with different moisture conditions is distinct, as well as reflectance of ice and snow under different environment or dissimilar mixtures have obvious development trends. The series of observations and analysis of the typical and complex spectral features in snowmelt period are of great significance for the fundamental study of objects’ spectral characteristics, as well as for the application of quantitative remote sensing studies..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1301 (2010)
A New Probe for Ca2+Based on the Rhodamine B Amide Armed Homotrioxacalix［3］ Arene-Sb3+Complex
ZHANG Wen-juan, WU Chong, ZENG Xi, MU Lan, XUE Sai-feng, and TAO Zhu
A new fluorescence probe based on the rhodamine B amide-armed homotrioxacalix［3］arene (1) has been synthesized, and its Ca2+-selective chromogenic properties were investigated in acetonitrile Tris-HCl buffer (pH 7) solution by UV-Vis and fluorescence spectroscopies. Upon the addition of Sb3+ ion, the spirocyclic ring oA new fluorescence probe based on the rhodamine B amide-armed homotrioxacalix［3］arene (1) has been synthesized, and its Ca2+-selective chromogenic properties were investigated in acetonitrile Tris-HCl buffer (pH 7) solution by UV-Vis and fluorescence spectroscopies. Upon the addition of Sb3+ ion, the spirocyclic ring of 1 was opened and a significant fluorescence enhancement and colorimetric change was observed. However, addition of Ca2+ ion to the solution of 1-Sb3+ complex leads to a strong fluorescence quenching of the original 1-Sb3+ complex. The phenomenon exhibited a pronounced Ca2+ selective fluoroionophoric behavior over other coexistent metal ions and provided the ratiometric determination as well as naked-eye detection of Ca2+ ions..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1305 (2010)
A Path-Length Correction Method on Biochemical Parameter Nondestructive Measuring of Folium
ZHANG Qian-xuan, ZHANG Guang-jun, and LI Qing-bo
Vis/NIR spectroscopy technology is capable of analyzing the content of biochemical parameter in folium rapidly and nondestructively. In the process of spectrum analysis, the variations in path-length between different samples exist, with the random light scattering and leaf thickness perturbations, which influence the Vis/NIR spectroscopy technology is capable of analyzing the content of biochemical parameter in folium rapidly and nondestructively. In the process of spectrum analysis, the variations in path-length between different samples exist, with the random light scattering and leaf thickness perturbations, which influence the precision of quantitative analysis model. In order to resolve this problem, an improved path-length correction method based on Extended Multiplicative Scattering Correction is presented. In this paper, firstly the theory of EMSC algorithm is deduced. EMSC method incorporates both chemical terms and wavelength functions to help realize the efficient separation of path-length and interest concentration. Secondly two experiments were implemented to demonstrate the validity of the method. In Experiment 1, sixteen samples of different thickness but almost the same chlorophyll content were selected, and how the path-length affects the spectrum was compared, after EMSC preprocessing, the variable coefficient of spectrum could approach the repeatability error of spectrometer. In Experiment 2, thirty-two samples of different thickness and chlorophyll content were selected. PLS model established using cross validation was employed to evaluate the efficiency of the presented algorithm. Before the preprocessing, the root mean squared error of prediction is 3.9 SPAD with 5 principal components. After preprocessing, the predicted root mean squared error is 2.2 SPAD with 12 principal components. The results indicate that the improved EMSC preprocessing method could exactly eliminate the spectrum difference caused by the path-length variations between different foliums, enhance the sensitivity of concentration and spectral data, and increase the precision of calibrated model..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1310 (2010)
A Rapid Quantificational Identification Model of Minerals and Its Applications
LI Shuai, LIN Qi-zhong, LIU Qing-jie, WANG Meng-fei, WANG Qin-jun, and WEI Yong-ming
Rapid identification of minerals is the key point for enhancing the efficiency of mineral exploration by remote sensing, mineral mapping by remote sensing and many geological investigations. Because of the limitation of technology and other aspects, the amount of models and software concerning rapid identification of mRapid identification of minerals is the key point for enhancing the efficiency of mineral exploration by remote sensing, mineral mapping by remote sensing and many geological investigations. Because of the limitation of technology and other aspects, the amount of models and software concerning rapid identification of minerals is very small. Since 1990s the development in spectrometers and computers has made it possible to apply near infrared spectrum technology to identify minerals. Two models have emerged. Model Ⅰ is based on analyzing the position of absorption bands, while Model Ⅱ is founded on waveform matching. In the present paper, characteristic spectrum linear inversion modeling was built. Validated by the data gained from end-members of USGS mineral spectrum library by mixing randomly, this model with the accuracy being approximately 100% is much better than Model Ⅰ and Ⅱ. Used to analyze the 23 samples selected in Baogutu area in Xinjiang, the model we built with the accuracy of 64.6% is superior to Model Ⅰ (the accuracy is 33.8%) and Model Ⅱ (the accuracy is 8.1%). Though the accuracy of our model is not as high as that of identification by microscope at present, using our model is much more effective and convenient, and there also will be less artificial error and smaller workload. The good performance of our model in the mineral exploration work by remote sensing in Baogutu area in Xinjiang shows wide popularizing prospects..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1315 (2010)
Study on the Geochemical Anomaly of Copper Element Based on Reflectance Spectra
LIU Miao, LIN Qi-zhong, WANG Qin-jun, and LI Hui
In order to explore the feasibility of studying the geochemical anomaly of copper element by using remote sensing method, the correlation between Cu and other elements and the correlation between Cu and reflectance spectra were analyzed based on the element contents and the reflectance spectra of rock samples. It was fIn order to explore the feasibility of studying the geochemical anomaly of copper element by using remote sensing method, the correlation between Cu and other elements and the correlation between Cu and reflectance spectra were analyzed based on the element contents and the reflectance spectra of rock samples. It was found that Fe is most highly correlated with Cu, followed by Ti and As. The relationship between the Cu content and the reflectance spectra is of a negative correlation, and the higher the Cu content, the stronger the correlation. Furthermore, based on the reflectance spectra, the partial least squares regression of the Cu, Fe, Ti and As content was carried out respectively. The result shows that Ti gets the highest accuracy, followed by Fe. The worst is for As. Although the accuracy of the Cu model is not too high, it is feasible to establish an indirect model of copper anomaly on the basis of Fe model because of the strong correlation between them. In order to improve the accuracy of the model, some transformations for the reflectance spectra were performed and many spectral indices were acquired. Based on the spectral indices, the partial least squares regression of Fe was carried out. The accuracy of the regression model increased greatly. The highest correlation coefficient of the regression model is 0.687 6 for the calibration samples and it is 0.595 9 for the validation samples..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1320 (2010)
Study on the Interaction between DNR-D3(Daunorubicin Derivative)and ctDNA by Spectroscopic Methods
Lv Juan, WANG Gong-ke, ZHANG Gui-sheng, LIU Qing-feng, and LU Yan
The interaction of DNR-D3(daunorubicin derivative)synthesized in our laboratory with ctDNA was investigated by UV spectrum and fluorescence spectrum under physiological conditions (pH 7.4) for the first time. The red shifts and hypochromicities were observed from the absorption titration experiments. These results suggThe interaction of DNR-D3(daunorubicin derivative)synthesized in our laboratory with ctDNA was investigated by UV spectrum and fluorescence spectrum under physiological conditions (pH 7.4) for the first time. The red shifts and hypochromicities were observed from the absorption titration experiments. These results suggest that DNR-D3 was intercalated into the DNA base pairs. Through the fluorescence quenching data measured at different temperatures (20 ℃, 30 ℃ and 37 ℃), it is known that the quenching mechanism of fluorescence of DNR-D3 by ctDNA is a static quenching type. On the other hand, the binding constant, the number of binding sites and thermodynamic parameters were also obtained. These data also indicate that the binding mode of the interaction between DNR-D3 and ctDNA is intercalation. Additionally, the types of interaction force are mainly hydrogen bonding and electrostatic interaction, and the binding is exothermic enthalpy-entropy cooperative driven process. When the degree of fluorescence quenching of DNR-D3 is 50%, the ratio of the molar concentration of DNR-D3 to ctDNA is 7/25, which indicates that the DNR-D3 anthracycline was intercalated into the DNA base pairs and that DNR-D3 showed a strong anticancer activity. DNR-D3 is expected to become one of the drug candidates from our investigations..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1324 (2010)
Preparation of Microencapsulated Red Phosphorus and Its Flame-Retardant Application in PP Composites
JIANG Wen-jun, LI Zhe-zhao, ZHANG Chun-xiang, FANG Jin, YANG Xu-jie, LU Lu-de, and PU Long-juan
In the present study, the melamine-formaldehyde prepolymer (MFP) was first synthesized at pH 8-8.5 under about 80 ℃ with melamine, formaldehyde, triethanolamine and methanol as the starting materials. Subsequently, the microencapsulated red phosphorus (MRP) was successfully prepared by in-situ polymerization at pH 5.5 In the present study, the melamine-formaldehyde prepolymer (MFP) was first synthesized at pH 8-8.5 under about 80 ℃ with melamine, formaldehyde, triethanolamine and methanol as the starting materials. Subsequently, the microencapsulated red phosphorus (MRP) was successfully prepared by in-situ polymerization at pH 5.5 under 65 ℃, using MFP and red phosphorus (RP) powders as raw materials, and potassium persulphate (KPS) as catalyst. The obtained products were detected by differential scan calorimetry (DSC), scanning electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). It was found that KPS is useful in enhancing the reaction activity of MFP, which can make RP be well encapsulated by melamine-formaldehyde resin (MF) and reduce the reaction time. The DSC, SEM and XPS results show that it won’t get well-encapsulated MRP only under acidic condition and without any KPS. When a proper quantity of KPS is employed, the RP particles can be almost completely-encapsulated by MF and the peak temperature of oxidation reaction for MRP is 480 ℃, which is much higher than that of RP, extending the applications for MRP. The FTIR spectrum demonstrates that the coating material on the surface of RP accurately is MF, in agreement with the reference. Polyproplene (PP) composites with different formulations were prepared by melt extrusion. It was shown that the flame-retardant efficiencies are very low when the PP composites only contain MRP or MH. However, the flame-retardant property can obviously improve if MRP and MH are both used in the PP composites. When PP∶MRP∶MH=100 (phr)∶15 (phr)∶50 (phr), the limited oxygen index of the MRP/MH/PP composite is 26%, and vertical firing ranks UL-94 V-0. In addition, the possible flame-retardant mechanism of the PP composites has also been discussed, and further verified by FTIR and Raman spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1329 (2010)
Research on Remote Sensing Inversion Biomass Method Based on the Suaeda Salsa’s Measured Spectrum
WU Tao, ZHAO Dong-zhi, KANG Jian-cheng, SUO An-ning, WEI Bao-quan, and MA Yu-juan
Suaeda salsa is one of characteristic vegetation of wetlands in Northern China. By measuring the spectral data and leaf area index (LAI) of the Suaeda salsa in the ShuangTai Estuary of Liaodong Bay by the use of portable spectrometer and vegetation canopy analyzer, collecting the biomass of the Suaeda salsa samples, seSuaeda salsa is one of characteristic vegetation of wetlands in Northern China. By measuring the spectral data and leaf area index (LAI) of the Suaeda salsa in the ShuangTai Estuary of Liaodong Bay by the use of portable spectrometer and vegetation canopy analyzer, collecting the biomass of the Suaeda salsa samples, setting up the spectral reflectance curve of the Suaeda salsa, probing into the relationship between the vegetation index and the leaf area index of the Suaeda salsa, carrying out regression analysis of LAI and biomass and constructing the function equation, some conclusion were drawn: (1) By the end of September the spectral characteristics of Suaeda salsa show that at the red band 630 nm there is a clear reflection of the peak with a reflection rate of 12%-15%; there is a clear “red valley” configuration between 680 and 700 nm, and there is a clear “red edge” reflection rate of 25%-30% about 760 nm. (2) It was found that there is best correlation between vegetation index (SAVI and MSAVI) and LAI compared to other vegetation index in the regression analysis of the LAI and vegetation index. The correlation coefficient R2 is 0.711. By comparison of vegetation index linear regression equations, the correlation coefficient (SAVI and LAI) R2 is 0.696; the value of R2 (LAI and MSAV) is 0.695; the value of R2 (RVI) is 0.664; the value of R2 (NDVI) is 0.649 and the value of R2 (PVI) is 0.466. (3) The value of correlation coefficient is low between the biomass and the vegetation indexes (RVI and NDVI) and the value of linear regression equation’s R2 is 0.342 and 0.316, and the Logarithmic regression equation’s R2 is 0.319 and 0.21, and the quadratic equation’s R2 is 0.589 and 0.568, the value of correlation coefficient is high between the biomass and the vegetation indexes (PVI, SAVI and MSAVI), the value of linear regression equation is 0.626, 0.698 and 0.679, that of logarithmic regression equation is 0.592, 0.706 and 0.683 and that of the quadratic equation is 0.688, 0.711 and 0.683..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1336 (2010)
Synthesis and Spectra of Copper(Ⅰ) Bromide Complex with N,N-Bis［(Diphenylphosphino)Methyl］-2-Pyridinylamine
CHI Shao-ming, ZHANG Jun-feng, BIAN Zhao-yong, and FU Wen-fu
A new ligand N,N-bis［(diphenylphosphino)methyl］-2-pyridinylamine (L) and its luminescent dinuclear copper(Ⅰ) complex ［CuBrL］2 (1) were synthesized and characterized by mass spectrometry, elemental analysis, NMR and electronic spectroscopies. The structure of complex 1 was determined by X-ray crystal analysis to be a diA new ligand N,N-bis［(diphenylphosphino)methyl］-2-pyridinylamine (L) and its luminescent dinuclear copper(Ⅰ) complex ［CuBrL］2 (1) were synthesized and characterized by mass spectrometry, elemental analysis, NMR and electronic spectroscopies. The structure of complex 1 was determined by X-ray crystal analysis to be a dinuclear complex with a pseudo-tetrahedral geometry. The complex 1 crystallizes in a triclinic space group P-1 and has two copper(Ⅰ) centers bridged by two halogen ligands to form the dinuclear structure with a four-membered Cu2Br2 ring. The Cu-Cu distance in complex 1 is 0.306 0 nm which is longer than a sum of Van der Waals radius of two copper(Ⅰ) atoms. Therefore there is no substantial interaction between the two copper(Ⅰ) centers in complex 1. DFT calculations indicate that the electron density of HOMO is distributed mainly over the copper, bromine and phosphorus atoms, while that of LUMO is localized on the ligand. Our work shows that there are two mechanisms to form the the lowest excited state of complex 1, i.e. the metal-to-ligand charge transfer (MLCT) and halogen-to-ligand charge transfer (XLCT)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1342 (2010)
Effect of Remotely Sensed Data Errors on the Retrieving Accuracy of Territorial Parameters——a Case Study on Chlorophyll a Concentration Inversion of Taihu Lake
CHEN Jun, ZHOU Guan-hua, WEN Zhen-he, and FU Jun
The errors of the territorial parameters retrieved from remote sensing are decided by the data error and the model error. The data error is not simply added to the total errors of retrieval results. It would be reformed by the quantitative inversion model, and then, combined with the model errors and melts into the totThe errors of the territorial parameters retrieved from remote sensing are decided by the data error and the model error. The data error is not simply added to the total errors of retrieval results. It would be reformed by the quantitative inversion model, and then, combined with the model errors and melts into the totals errors. Accordingly, during the quantitative process, taking advantage of the highest correlation coefficient or the least root mean square error as assessment standard for describing the chlorophyll a concentration vs remote sensing parameters is not reasonable. Focusing on the above problem, the study pointed out that the reason why the result of the optimized cost function is contrary with the practical is that different model has different influence on data errors. Combined with the in situ measurements of Taihu Lake, in October, 2003, it is known that due to the error magnification phenomena (TM2/TM3 algorithm is 2.28 times more than TM2/TM1 algorithm), although the regression coefficient of TM2/TM3 algorithm is higher than TM2/TM1 algorithm, the quantitative errors of TM2/TM3 algorithm are 7.938 5 μg·L-1 more than TM2/TM1 algorithm. Moreover, the retrieval results show that distribution pattern of the results of TM2/TM3 algorithm is completely opposite to the TM2/TM1 algorithm. According to the former research achievements, the results of TM2/TM1 algorithm would be more reasonable. In summary, only when that the factor of data error is added to the optimized cost function is taken as a constrain condition in search for the optimal solution of the quantitative models, would the retrieval results be more reliable..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1347 (2010)
An Investigation of Temperature Compensation of HCL Gas Online Monitoring Based on TDLAS Method
SHU Xiao-wen, ZHANG Yu-jun, KAN Rui-feng, CUI Yi-ben, HE Ying, ZHANG Shuai, GENG Hui, and LIU Wen-qing
HCL, with the character of strong erosion and toxicity, is a kind of chemical material of vital importance. So measuring the HCL in-situ can not only optimize its production process, but also be necessary to reduce the environment pollution. TDLAS(tunable diode laser absorption spectroscopy)technology, and owning the aHCL, with the character of strong erosion and toxicity, is a kind of chemical material of vital importance. So measuring the HCL in-situ can not only optimize its production process, but also be necessary to reduce the environment pollution. TDLAS(tunable diode laser absorption spectroscopy)technology, and owning the advantage of the tunability and narrow line width of the diode laser, this method can relatively easily select the absorption line of the detected gas without the interference from other gas, thus making the rapid and accurate HCL measurement possible. In the present paper, the HCL measurement system and the implemented experiment are introduced. The impact of the temperature on the measurement as well as the temperature compensation method is emphasized. The final experimental results validated the rationality of the empirical equation and therefore the improvement of the accuracy and feasibility of the TDLAS technology .The system, whose detection limitation reaches 2 ppm, can satisfy the needs of industrial in-sit measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1352 (2010)
Identification of Cucumber Disease Using Hyperspectral Imaging and Discriminate Analysis
CHAI A-li, LIAO Ning-fang, TIAN Li-xun, SHI Yan-xia, and LI Bao-ju
Hyperspectral imaging(400-720 nm) and discriminate analysis were investigated for the detection of normal and diseased cucumber leaf samples with powdery mildew(Sphaerotheca fuliginea), angular leaf spot(Pseudomopnas syringae), downy mildew(Pseudoperonospora cubensis), and brown spot(Corynespora cassiicola). A hyperspeHyperspectral imaging(400-720 nm) and discriminate analysis were investigated for the detection of normal and diseased cucumber leaf samples with powdery mildew(Sphaerotheca fuliginea), angular leaf spot(Pseudomopnas syringae), downy mildew(Pseudoperonospora cubensis), and brown spot(Corynespora cassiicola). A hyperspectral imaging system was established to acquire and pre-process leaf images, as well as to extract leaf spectral properties. Owing to the complexity of the original spectral data, stepwise discriminate and canonical discriminate were executed to reduce the numerous spectral information, in order to decrease the amount of calculation and improve the accuracy. By the stepwise discriminate we selected 12 optimal wavelengths from the original 55 wavelengths, and after the canonical discriminate, the 55 wavelengths were reduced to 2 canonical variables. Then the discriminate models were developed to classify the leaf samples. The result shows that the stepwise discriminate model achieved classification accuracies of 100% and 94% for the training and testing sets, respectively. For the canonical model, the classification accuracies for the training and testing sets were both 100%. These results indicated that it is feasible to identify and classify cucumber diseases using hyperspectral imaging technology and discriminate analysis. The preliminary study, which was done in a closed room with restrictions to avoid interference of the field environment, showed that there is a potential to establish an online field application in cucumber disease detection based on visible spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1357 (2010)
Study on Microstructure of J-Aggregates of Cyanine Dyes
MENG Tao, KANG Ling-hua, ZHOU Hui, ZHANG Ao, WANG Du-jin, LI Xiao-wei, and ZOU Jing
In the present paper, the J-aggregate structures of three types of cyanine dyes adsorbed both on 0.4 μm AgBrI cubic crystal surface (100) and on 1.8 μm AgBrI tabular crystal surface (111) were studied by use of atomic force microscope (AFM). Several types of aggregation structures were observed for the three types of dIn the present paper, the J-aggregate structures of three types of cyanine dyes adsorbed both on 0.4 μm AgBrI cubic crystal surface (100) and on 1.8 μm AgBrI tabular crystal surface (111) were studied by use of atomic force microscope (AFM). Several types of aggregation structures were observed for the three types of dyes on AgBrI crystals. Rectangular structure was formed on the crystal faces of (100) and (111) for both anionic and cationic cyanine dyes. On the surface of anionic-cationic cyanine dyes, however, herringbone stacking structure was formed, and a banded spectrum was correspondingly detected on the AgBrI crystal surface..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1362 (2010)
The Application of Chemical Imaging to Detection and Enhancement of Latent Fingerprints
XIA Bin-bin, YANG Rui-qin, and WANG Yan-ji
Chemical imaging (CI) integrates conventional imaging and spectroscopy to attain both spectral and spatial components and structural information from an object simultaneously. Vibrational spectroscopic methods, such as infrared and Raman spectroscopy, combined with imaging are particularly useful. In recent years, CI hChemical imaging (CI) integrates conventional imaging and spectroscopy to attain both spectral and spatial components and structural information from an object simultaneously. Vibrational spectroscopic methods, such as infrared and Raman spectroscopy, combined with imaging are particularly useful. In recent years, CI has found important application in the field of forensic science due to its advantage of highly sensitive, rapid, non-destructive features and it can provide qualitative and quantitative information about specimen at one time. There are many methods for detection and enhancement of latent fingerprints. CI is an emerging platform technology with great potential to visualize latent fingerprints on many objects without any pre-treatment. CI can enhance the quality of the fingerprints developed by conventional methods, then form larger contrast with the background. With the advancement of instruments, the application of CI in the field of fingerprint detection will be more widely used. This paper provides an overview of the principal and classification of CI instrumentation, and reviews the application of CI to detection and enhancement of latent fingerprints. Finally, the direction of CI technology development is viewed..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1367 (2010)
Analysis of Color Gamut of LCD System Based on LED Backlight with Area-Controlling Technique
LI Fu-wen, JIN Wei-qi, SHAO Xi-bin, ZHANG Li-lei, and WAN Li-fang
Color gamut as a significant performance index for display system describes the color reproduction ability IN real scenes. liquid crystal display (LCD) is the most popular technology in flat panel display. However, conventional cold cathode fluorescent lamp (CCFL) backlight of LCD can not behave high color gamut comparColor gamut as a significant performance index for display system describes the color reproduction ability IN real scenes. liquid crystal display (LCD) is the most popular technology in flat panel display. However, conventional cold cathode fluorescent lamp (CCFL) backlight of LCD can not behave high color gamut compared with cathode ray tube (CRT). The common used method of color gamut measuring for LCD system is introduced at the beginning. According to the inner structure and display principle of LCD system, there are three major factors deciding LCD’s color gamut: spectral properties of backlight, transmittance properties of color filters and performance of liquid crystal panel. Instead of conventional backlight CCFL, RGB-LED backlight is used for improving color reproduction of LCD display system. Due to the imperfect match between RGB-LED’s spectra and color filter’s transmittance, the color filter would reduce the color gamut of LCD system more or less. Therefore, LCD system based on LED backlight with area-control technique is introduced which modifies backlight control signal according to the input signal. After analyzing and calculating the spectra of LED backlight which passes through the color filters using method of colorimetry, the area sizes of color gamut triangles of RGB-LED backlight with area-control and RGB-LED backlight without area-control LCD systems are compared and the relationship between color gamut and varying contrast of liquid crystal panel is analyzed. It is indicated that LED backlight with area-control technique can avoid color saturation dropping and have little effects on the contrast variation of liquid crystal panel. In other words, LED backlight with area-control technique relaxes the requirements of both color filter performance and liquid crystal panel. Thus, it is of importance to improve the color gamut of the current LCD system with area-control LED backlight..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1371 (2010)
Study of Vibrational Spectra of Humic Substance in Soils from the Three Gorges Reservoir Area
HU Xue-bin, JI Fang-ying, LI Si, ZHOU Guang-ming, YU Dan-ni, TAN Xue-mei, YANG Da-cheng, and YU Bing
The six typical different parts of soils and sediments along the bank of the Three Gorges Reservoir Area (TGRA) were collected, and the humic substance isolated from the six parts of the soils and sediments’ samples was separated to humic acid and fulvic acid, purified, and characterized with the combination of the RamThe six typical different parts of soils and sediments along the bank of the Three Gorges Reservoir Area (TGRA) were collected, and the humic substance isolated from the six parts of the soils and sediments’ samples was separated to humic acid and fulvic acid, purified, and characterized with the combination of the Raman and IR vibrational spectroscopic technologies after cool-dried separation; through assigning the vibrational peaks in each part of the Raman and IR spectra of each sample part, the vibrational characteristics of the structures and the groups that belonged to the molecules of the humic acids and the fulvic acids in the soils and sediments of the TGRA were obtained; the changing features of the groups and structures in the humic acid and the fulvic aicd’s molecules from the different soils and sediments in the TGRA were discussed with the environmental impact factors such as soil humic degree, the conditions of different soils conference, using and/or cultivating models and water level fluctuations. From the experimental results, the vibrations about C—O, C—C, and poly-hydrogen bonds dominate in the structures and the groups of each part’ humic substance; the active vibration numbers in the upstream are more than in the downstream; the soil’s humic degree has great effect on the formation of the humic substances’ structures in soil’s humic substance; the soil used as agricultural cultivating mode showed higher humic degrees in the upstream parts of the TGRA. The effect of the water level’s fluctuation on the formation of the humic acid and fulvic aicd in the sediments of the TGRA is not obvious in the short time..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1376 (2010)
Theoretical Studies on the Structure, Thermodynamics and Spectral Properties of Rhodamine Derivatives Modified by Amino of Central Ring
LEI Yong-lin, and HUO Ji-chuan
The structures of three rhodamine derivatives were optimized by means of DFT/B3LYP method, and the data of the structural parameters and thermodynamic parameters of the excited state and ground state of the three rhodamine derivatives and their vibrational spectra and frontier molecular orbital energy level were obtainThe structures of three rhodamine derivatives were optimized by means of DFT/B3LYP method, and the data of the structural parameters and thermodynamic parameters of the excited state and ground state of the three rhodamine derivatives and their vibrational spectra and frontier molecular orbital energy level were obtained. On the basis of fully optimized structures of excited state and ground state, their gas absorption and emission spectra were studied by time-dependent density functional theory (TD-DFT), while the effects of their structural features on thermal stability, frontier molecular orbital and spectra properties were fully analyzed. The results indicate that the compound a has the lowest reverse movement degree of terminal amino among these molecules, and in contrast, the compound b was better conjugated and planar, the reverse movement degree of terminal amino improved, the gas absorption and emission spectra were red shifted, and it has the longest maximum emission wavelength and the lowest thermal stability among these molecules. The compound c was best conjugated and planar, its thermal stability and energy of HOMO were the highest, its HOMO-LUMO gap was most narrow, and it has the longest maximum absorption wavelength. It was found that the reverse movement degree of terminal amino of compound c improved compared to b, so its maximum emission wavelength was blue shifted..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1381 (2010)
Antioxidant Activity and Spectroscopic Behavior Study with DNA of Several Salen Mn(Ⅱ), Eu(Ⅲ) Complexes
ZHOU Hua-lei, DONG Yi-fan, YANG Yun-xu, DENG Xiao-rong, and LU Yi-qiang
Five kinds of Salen Mn(Ⅱ) and two kinds of Eu(Ⅲ) complexes were synthesized. Under the system of NBT/L-methionine, which creats and detects O·-2, the complexes of antioxidant activity were studied, and the conclusion revealed that all Mn(Ⅱ) complexes have obvious antioxidant activity. The fluorescence study indicaFive kinds of Salen Mn(Ⅱ) and two kinds of Eu(Ⅲ) complexes were synthesized. Under the system of NBT/L-methionine, which creats and detects O·-2, the complexes of antioxidant activity were studied, and the conclusion revealed that all Mn(Ⅱ) complexes have obvious antioxidant activity. The fluorescence study indicated that all the Salen metal complexes could bind with DNA, which shows their potential anticancer activity..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1386 (2010)
Analysis of the Effects of pH and Salt on the Conformation of the Sericin Particles by DLS and TEM Measurements
WU Li-ping, LENG Xiao-jing, SUN Yan, REN Fa-zheng, and Nakai Shuryo
The particles conformation of the sericin protein extracted from silkworm Bombyx mori was studied under the conditions of different pH and salt concentrations by infrared spectroscopy (IR), dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. The IR spectrum of sericin protein arises The particles conformation of the sericin protein extracted from silkworm Bombyx mori was studied under the conditions of different pH and salt concentrations by infrared spectroscopy (IR), dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. The IR spectrum of sericin protein arises predominantly from CO stretching vibration around the amide I region of 1 700-1 600 cm-1. A strong trend of aggregation of the protein could be observed under specified experimental conditions. The apparent isoelectric point of the sericin protein was about 3.7. The DLS method was used to investigate the effects of pH and NaCl on the size distribution, where a large polydispersity of the system could be observed. Compared to pH 4 or high NaCl concentration, at pH 3, 8 or low NaCl concentration the sericin aggregation shows a relatively smaller size but larger polydispersity. TEM was used to investigate the microstructure of the aggregated sericin protein, where a loose and pine-like branched form could be observed at pH 3 or 8; however, a relatively compact structure was observed near pH 4 or at high salt concentration. At pH 4 the spherical monomer size can be calculated at around (60±6) nm (n=10) by TEM measurement. These phenomena could be explained by the effects of the electrostatic repulsion, hydrogen bonding and Van der Waals attractive force, which provide a basic theory for the application of sericin as biomaterial..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1391 (2010)
Determination of Trace Au in Mine Sample by Inductively Coupled Plasma Atomic Emission Spectroscopy
JI Chun-hong, LI Jian-qiang, HUANG Wen-jie, BAO Rui, GUO Ru, and HU Jun-jie
A method for the determination of trace gold by inductively coupled plasma atomic emission spectrometry (ICP-AES) in mine sample was proposed. The instrument parameters were optimized and the media of solution and interferences were studied systemically. The results showed that in less than 10%(φ) aqua regia medium, thA method for the determination of trace gold by inductively coupled plasma atomic emission spectrometry (ICP-AES) in mine sample was proposed. The instrument parameters were optimized and the media of solution and interferences were studied systemically. The results showed that in less than 10%(φ) aqua regia medium, the acids had no influences on the determination, and after removing common cations in mineral samples by using 10% hydrochloric acid(φ), the residual matrix elements had no effect on the determination of Au with ICP-AES. The silicon in samples had serious spectral interference to Au 208.2 nm, and the spectral interference was corrected with interference coefficient using the 251.6 nm silicon line. With 10% HCl to remove the matrix and interference correction coefficient to eliminate the interference of silicon, trace gold in high-sulfur tailings samples was determined, the result was identical with the reference values by the method of enrichment with activated carbon-atomic absorption spectrometry. Under the experimental conditions, the detection limit for gold in mine sample was 0.10 g·t-1..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1396 (2010)
Research on the Content of Trace Elements and Heavy Metals in the Three Kinds of Zhejiang Specific Medicinal Materials before and after Processing
YUAN Ke, WANG Lin, SUN Su-qin, and YIN Ming-wen
By establishing the ICP-MS determining method, we determined the contents of Mn, Fe, Cu, Zn, Cr, As, Cd and Pb in the three kinds of ZheJiang specific medicinal materials before and after processing them. The recovery ratio with standard addition of the method is between 95.2％and 106.3, and the relative standard deviatBy establishing the ICP-MS determining method, we determined the contents of Mn, Fe, Cu, Zn, Cr, As, Cd and Pb in the three kinds of ZheJiang specific medicinal materials before and after processing them. The recovery ratio with standard addition of the method is between 95.2％and 106.3, and the relative standard deviation between 0.69％and 2.34％. The results of the experiment show that the contents of useful metals Mn, Fe, Cu and Zn are fairly high both before and after processing, while the contents of harmful heavy metals Cd, Cr, Pb and As are all lower than the limited quantity in the standard of Chinese Pharmacopoeia. After processing, there seems to be some content changes in the trace elements and heavy metals. Different content changes depend on different processing methods. After processing, except the notable decrease in Pb, the contents of Cu, As and Cd are almost constant, while the contents of other elements are nearly all increased. The result seems to be related with the methods of processing. This experimental result provides us with new scientific foundation for the further research on the relationship between different processing methods and different efficacy of the three specific Zhejiang medicinal materials..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1400 (2010)
Analysis of the Microfibrilla Angles & Crystallinity Index of Daemonorops Margaritae with X-Ray Diffractometry and the Effects of γ-Ray Irradiation
WANG You-hong, LIU Xing-e, JIANG Ze-hui, FEI Ben-hua, and REN Hai-qing
In order to find out the properties and improve the levels of high value-added processing and utilization of Chinese rattan resources, the Daemonorops Margaritae, a Chinese unique rattan, was chosen as the research material, then the microfibril angles (MFA) & crystallinity index (CrI) were measured through the X-rIn order to find out the properties and improve the levels of high value-added processing and utilization of Chinese rattan resources, the Daemonorops Margaritae, a Chinese unique rattan, was chosen as the research material, then the microfibril angles (MFA) & crystallinity index (CrI) were measured through the X-ray diffraction method, and the effects of γ-ray irradiation upon the MFA & CrI were analyzed. The results show that the MFA of the cane varied from 33.4° to 38.7° with the average value of 36.1°, and the MFA of the coretex were not larger than that of the core. The MFA were 36.2 and 35.8 degrees, 35.9 and 35.4 degrees, and 36.2 and 35.4 degrees before and after irradiation with a radiation dose rate of 2.5×103 Gy·h-1 and radiation dose of 3, 9 and 15 kGy, and decreased 1.10%, 1.39% and 2.21% respectively compared with the former. The CrI was in the range of 24.8%-32.0%, and the average CrI was 28.6%. The CrI of coretex was larger than that of the core. Under the same radiation conditions, the CrI was 28.1% and 26.0%, 28.1% and 26.9%, and 28.5% and 27.1% before and after irradiation, and the latter decreased 7.58%, 4.34% and 4.70% respectively compared to the former. With the radiation dose of 3 kGy, the differences in CrI between with and without irradiation were most notable in the 0.001 level..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1404 (2010)
XPS Analysis of Beads Formed by Fuse Breaking of Electric Copper Wire
WU Ying, MENG Qing-shan, WANG Xin-ming, GAO Wei, and DI Man
The in-depth composition of beads formed by fuse breaking of the electric copper wire in different circumstances was studied by XPS with Ar+ ion sputtering. In addition, the measured Auger spectra and the calculated Auger parameters were compared for differentiation of the substances of Cu and Cu2O. Corresponding to thThe in-depth composition of beads formed by fuse breaking of the electric copper wire in different circumstances was studied by XPS with Ar+ ion sputtering. In addition, the measured Auger spectra and the calculated Auger parameters were compared for differentiation of the substances of Cu and Cu2O. Corresponding to the sputtering depth, the molten product on a bead induced directly by fuse breaking of the copper wire without cover may be distinguished as three portions: surface layer with a drastic decrease in carbon content; intermediate layer with a gentle change in oxygen content and gradually diminished carbon peak, and consisting of Cu2O; transition layer without Cu2O and with a rapid decrease in oxygen content. While the molten product on a bead formed by fuse breaking of the cupper wire after its insulating cover had been burned out may be distinguished as two portions: surface layer with carbon content decreasing quickly; subsurface layer without Cu2O and with carbon and oxygen content decreasing gradually. Thus, it can be seen that there was an obvious interface between the layered surface product and the substrate for the first type of bead, while as to the second type of bead there was no interface. As a result, the presence of Cu2O and the quantitative results can be used to identify the molten product on a bead induced directly by fuse breaking of the copper wire without cover and the molten product on a bead formed by fuse breaking of the cupper wire after its insulating cover had been burned out, as a complementary technique for the judgments of fire cause..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1408 (2010)
Vertical Cavity Semiconductor Optical Amplifiers
SUN Cheng-lin, LIANG Xue-mei, QIN Li, JIA Li-hua, NING Yong-qiang, and WANG Li-jun
Based on the broad-area vertical cavity semiconductor optical amplifiers (VCSOA) of 970 nm, the amplifier gain and bandwidth characteristics were experimentally investigated and analyzed in the reflection mode. For 970 nm broad-area VCSOA operated in reflective mode, the maximum gain amplification of 24.8 dB and opticaBased on the broad-area vertical cavity semiconductor optical amplifiers (VCSOA) of 970 nm, the amplifier gain and bandwidth characteristics were experimentally investigated and analyzed in the reflection mode. For 970 nm broad-area VCSOA operated in reflective mode, the maximum gain amplification of 24.8 dB and optical bandwidth of 0.14 nm (25 GHz) were reached when the injection current was 57% of threshold current and the signal input power was 0.7 W. The experimental gain value was larger than the theoretical value, due to many modes existing in VCSOA. Each mode had relative gain amplification, so the experimental gain value was larger than the theoretical value. This kind of broad-area VCSOA was improved not only in optical gain but also in saturated input power. The authors optimized the structure design of the wide area VCSOA of 970 nm. The simulation results showed that the improvement of the gain and bandwidth of the semiconductor laser could be obtained by appropriately reducing the DBR reflectivity of the emitting laser on the vertical cavity surface..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1413 (2010)
Wide-Range Fiber Spectral Instrument Covering
ZHENG Bao-hua, CHENG De-fu, ZHENG Zhi-zhong, and XIU Lian-cun
To meet the requirements of outdoor field mineral analysis and remote sensing ground verification spectral analysis, the wide-range fiber spectral instrument covering 400 nm-2 500 nm was developed. The present article illustrates the design of the optical, mechanical and electrical parts of the instrument. The optical To meet the requirements of outdoor field mineral analysis and remote sensing ground verification spectral analysis, the wide-range fiber spectral instrument covering 400 nm-2 500 nm was developed. The present article illustrates the design of the optical, mechanical and electrical parts of the instrument. The optical system utilizes grating horizontal-reflecting light route to implement the full coverage of the spectrum. Three line-array sensors are intercrossed in three directions on the spectrum surface to sense different spectrum ranges. CPLD device generates the sampling and driving temporal logic signals to the three line-array photoelectrical devices. Fourteen bits high speed AD converts the analog signals into digital ones. USB 2.0 is used for communication. The final results demonstrate that while implementing the measurement of wide spectrum, the instrument is improved in size, spectrum resolving power, signal quality and measuring speed. Ideal spectrum data were acquired..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1417 (2010)
Comparison of Two Types of Fourier Transform Imaging Spectrometry
XIANGLI Bin, Lv Qun-bo, HUANG Min, and YAO Tao
The comparison between “large aperture static imaging spectrometry (LASIS)” designed by author and “method for simultaneously measuring the spectral intensity as a function of wavelength of all the pixels of a two dimensional scene” (MSMSI) designed by Israeli researchers is given. The difference of the interferometersThe comparison between “large aperture static imaging spectrometry (LASIS)” designed by author and “method for simultaneously measuring the spectral intensity as a function of wavelength of all the pixels of a two dimensional scene” (MSMSI) designed by Israeli researchers is given. The difference of the interferometers and imaging systems in LASIS and MSMSI is discussed. The nonlinear curve of optical path difference of MSMSI is simulated. Inspired by the operation of MSMSI, the time modulated Fourier transform imaging spectrometry based on lateral shearing interferometer was presented. The optical path differences of different field of view were given under the condition of regularly rotating the lateral shearing interferometer..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1422 (2010)
Research on Degradation of Methylene Blue by Coal Bottom Ash-Microwave Irradiation Method
WU Shi-wei, LI Na, LI Guang-zhe, and LI Guo-de
Coal bottom ash is rich in metals and transition metals, and with microwave irradiation these metals can effectively degradate organic matter. Methylene blue degradation by coal bottom ash-microwave irradiation mainly through hydroxyl radicals to degrade organic matter, and metals and rare metals in bottom ash can be uCoal bottom ash is rich in metals and transition metals, and with microwave irradiation these metals can effectively degradate organic matter. Methylene blue degradation by coal bottom ash-microwave irradiation mainly through hydroxyl radicals to degrade organic matter, and metals and rare metals in bottom ash can be used as a catalyst for deep oxidation of organic matter, can reduce processing costs, and reduce environmental pollution. In the present paper the main parameters including the amount of coal bottom ash, H2O2 dosage and time of microwave irradiation were investigated. The UV-visible spectra of methylene blue were determined. The results show that: under coal bottom ash and H2O2 microwave condition the degeneration rate of methylene blue was almost 100%. The dosage of coal ash can accelerate the reaction process, speeding up the degradation of methylene blue. The increase of H2O2 may provide more ·OH and speed up the reaction process, but when up to a certain amount, the influence is weakened. The lengthening of microwave time may enhance the reaction temperature, and urge the methylene blue to degrade completely. For 0.125 g·L-1 of methylene blue, by adding 1.0 g coal bottom ash, 5 mL H2O2 and under mesotherm microwave temperature for 4 min, the methylene blue can be all degradated..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1427 (2010)
Spectrum Recovery Methods for Nonuniform Sampling Interferogram
YAO Tao, Lv Qun-bo, XIANGLI Bin, and YUAN Yan
The interferogram acquired by imaging Fourier transform spectrometer (IFTS) can’t be used directly and must be recovered. The spectrum recovery processes based on fast Fourier transform (FFT) is the traditional method which is used widely. For some IFTS, the nonuniform sampling of the interferogram is often occurrs. WhThe interferogram acquired by imaging Fourier transform spectrometer (IFTS) can’t be used directly and must be recovered. The spectrum recovery processes based on fast Fourier transform (FFT) is the traditional method which is used widely. For some IFTS, the nonuniform sampling of the interferogram is often occurrs. When the aliasing is neglected, the spectrum recovered by traditional method is often distorted. When the spectrum recovery processes based on Fourier transform are used, the precision of the recovered spectrum can be ensured, but the real-time processing requirement can’t be satisfied. In order to acquire the precise recovered spectrum of the nonuniform sampled interferogram, the interpolation method and nonuniform fast Fourier transform (NUFFT) method were adopted. For the oversampled interferogram and partial undersampled interferogram, the spectrum recovery methods based on interpolation and NUFFT were presented respectively, and the applicability of these two methods is given. Finally, the computer simulation was performed, and the results indicate that NUFFT method is preferable to interpolation method not for undersampled interferogram but for oversampled interferogram..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1430 (2010)
Research on Fiber Methane Sensing System Based on Prism Gas Cell
WU Xi-jun, WANG Yu-tian, LIU Xue-cai, and LI Shu-jun
A novel fiber methane detection system was constructed based on integration of prism gas cell and harmonic detection technique. The system can be applied to broad-range concentration detection. Grounded on the Beer-Lambert approximation, the detection of various concentration (0-20%) of methane was completed using subtA novel fiber methane detection system was constructed based on integration of prism gas cell and harmonic detection technique. The system can be applied to broad-range concentration detection. Grounded on the Beer-Lambert approximation, the detection of various concentration (0-20%) of methane was completed using subtraction of background and ratio processing method, as the atmosphere surroundings was treated as background. The direct absorption spectra for various concentration were measured using GRIN gas cell, combined with available DFB-LD, and the R5 line of the 2ν3 band of methane was selected as absorption peak. The system was tested online during gas mixing process and the linear relation between system indication and concentration variation was validated, while the stability and dynamic response characteristics was confirmed by experiments. The system sensitivity can be adjusted according to the concentration level of various field environments by changing the prism distance using step motor. So that, the system can be applied to various application fields and can be adopted as a monitoring instrument for coalmine tunnel and natural gas pipeline..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 5, 1434 (2010)
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