Journals >Spectroscopy and Spectral Analysis
Contents
2017
Volume: 37 Issue 6
63 Article(s)
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Elemental Analysis of Alloy Sample with Pulsed Micro-Discharge Optical Emission Spectrometry
WANG Xiao-hua, LI Wei-feng, GUO Zong-wei, HANG Wei, and HUANG Ben-li
The pulsed micro-discharge ablation source was applied to the optical spectra analysis of the aluminum alloy at atmospheric pressure. This needle-plane micro-discharge device has the merits of low cost, easy operation and fast analysis. Pulsed discharge allows large instantaneous input power without melting the sample,The pulsed micro-discharge ablation source was applied to the optical spectra analysis of the aluminum alloy at atmospheric pressure. This needle-plane micro-discharge device has the merits of low cost, easy operation and fast analysis. Pulsed discharge allows large instantaneous input power without melting the sample, which is vital to keep the stability of the discharge. In the duration of a few microseconds, high voltage of about -4 000 V was applied to the tungsten needle electrode, which quickly initiates a discharge channel between the electrode and electrode, and results in current of 20 A between the tungsten needle tip and the sample. Thus, the sample was ablated before ablated particles were excited. The deposition energy, whose value was approximately 85 mJ per discharge pulse, was transmitted between the two discharge electrodes by means of the electric current. The surface morphology of the ablation crater generated by this pulsed needle-plane discharge indicated that a local micro-plasma was formed in the electrode gap. In addition, the on-axial energy flux and current density were much higher than those of the off-axis region. In order to further investigate the ablation mechanisms and physical properties, the electrical characteristic of this plasma source was discussed. The time evolution process of the discharge plasma was studied through precise timing shooting technique. From the fast imaging results of the ICCD camera, it could be seen that the lifetime of the plasma source was comparable with the pulse width of the high-voltage discharge source, and what was more, the change of optical intensity of plasma source showed good agreement with the variation of discharge current. Combined with an optical spectrometer, the pulsed micro-discharge ablation source could well excite atomic lines of aluminum, magnesium, manganese, bronze, and more in the alloy sample. The spectral characteristics of the discharge plasma were studied further. The electron excitation temperature of the discharge plasma was determined as about 6 700 K and the electron number density was obtained in the order of 1017 cm-3 using the Boltzmann plot method and Stark broadening of line, respectively. Besides, it was verified that the discharge plasma generated in this experiment was in local thermal equilibrium state. A further attempt was made to demonstrate the ability of this technique in quantitative analysis. Our results showed that the pulse micro-discharge plasma employed as spectral analysis source was an effective method for the quantitative analysis of aluminum alloy sample..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1661 (2017)
Development of Magnetic and Fluorescent Immune Sensors for the Detection of Alpha Fetoprotein
LI Yi-ke, FENG Ting, DENG Sui-min, WANG Xiang-feng, and XIE Meng-xia
Alpha fetoprotein (AFP) is one of the most widely used tumor biomarkers with significant values in early diagnosis of liver cancer. We designed both magnetic and fluorescent immune sensors in this work and utilized them in the detection of AFP in solutions. For the magnetic immune sensor, the immunomagnetic beads were Alpha fetoprotein (AFP) is one of the most widely used tumor biomarkers with significant values in early diagnosis of liver cancer. We designed both magnetic and fluorescent immune sensors in this work and utilized them in the detection of AFP in solutions. For the magnetic immune sensor, the immunomagnetic beads were applied to replace the traditional solid support because the immunomagnetic beads had larger specific surface areas which ensured the sufficiency of the antibody-antigen reaction. With the help of magnetic response, the separation process could be achieved rapidly, which was time-saving and nondestructive. Horseradish Peroxidase (HRP) on the Ab2 could catalyze the substrates to chromogenic products which could be tested with UV-Vis spectrophotometry. The method had a correlation in the range of 10~80 ng·mL-1 with a detection limit of 36 ng·mL-1. For the fluorescent immune sensor, we considered the fluorescence of CdTe QDs to be the output signal, and at the same time, a signal amplification system was introduced by doping the CdTe QDs onto the surface of the silica nanospheres which were suitable as the carrier for their adjustable size and stable properties. The fluorescent intensity of CdTe QDs was tested to calculate the concentration of AFP. The method reached a detection limit of 42 ng·mL-1 with a linear range of 5~150 ng·mL-1. It was shown that both the developed magnetic and fluorescent immune sensors had high sensitivity to detect the concentration of AFP in solutions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1667 (2017)
Limitations of Spectral Subtraction in the Elimination of Infrared Water Vapor Bands
YU Min-xing, WANG Hai-shui, and ZHANG Yun-hong
Spectral subtraction is a powerful and conventional tool for the elimination of background interferences, but this technique has been suffered from severe limitations in the case of atmospheric water vapor. In order to understand the real reasons of the problems above , IR spectra of water vapor at different humidity hSpectral subtraction is a powerful and conventional tool for the elimination of background interferences, but this technique has been suffered from severe limitations in the case of atmospheric water vapor. In order to understand the real reasons of the problems above , IR spectra of water vapor at different humidity have been investigated. The following conclusions have been reached: (1) The spectral features of water vapor will change as the relative humidity of air changes. Namely, if the spectrum of atmospheric air with x% relative humidity is given, we cannot predict and obtain the spectrum of air with y% humidity regardless of how carefully the scaling factor has been chosen. In general, spectral subtraction is not a good practice to remove water vapor interferences. (2) The relative composition of water clusters (H2O)n changes with the relative humidity, and this is the main reason of spectral subtraction limitation. (3) The spectrum of water vapor between relative humidity x% and y% can be matched near perfectly by a combination of x% spectrum and y% spectrum. This provides a new and effective way for the elimination of water vapor interferences. (4) The high efficiency of the humidity titration method has been demonstrated experimentally..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1673 (2017)
High-Resolution Atmospheric-Transmission Measurement with a Laser Heterodyne Radiometer
WU Qing-chuan, HUANG Yin-bo, TAN Tu, CAO Zhen-song, LIU Qiang, GAO Xiao-ming, and RAO Rui-zhong
Laser heterodyne technology is a highly sensitive laser spectroscopy technique which can be integrated. It has the potential to develop a compact ground or satellite based radiometer for Earth observation and astronomy. Based on the laser heterodyne technology, a set of high resolution laser heterodyne detection systemLaser heterodyne technology is a highly sensitive laser spectroscopy technique which can be integrated. It has the potential to develop a compact ground or satellite based radiometer for Earth observation and astronomy. Based on the laser heterodyne technology, a set of high resolution laser heterodyne detection system was established together with a solar tracker. The spectral resolution of the system is about 0006 cm-1. Sunlight is superimposed with infrared laser light in a nonlinear detector. The signals pass through an electronics filter and a square-law detector, then the high-resolution heterodyne signal is extracted. In terms of the field measurement, Langley-Plot Calibration method was used to calibrate the system first, then total atmosphere transmittance of mid-infrared was measured. The calibration constant and corresponding to the atmospheric total optical thickness were presented. According to the comparison between the results of heterodyne measurement system and that of software MORTRAN50 calculation, good agreement was obtained. It is shown that the system has high spectral resolution which can be applied to atmospheric transmittance measurement. Besides, the system also shows potential applications in atmospheric sciences, astronomy, laser propagation through the atmosphere and other areas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1678 (2017)
Analysis of Hydrogen Bond Structure in Ice Ih Surface of Film with Raman Spectra
LI Fa-bing, LI Zhan-long, MEN Zhi-wei, LI Ye-qiu, and OUYANG Shun-li
Water is one of the most important and basic materials in living systems which has been extensively studied because of its peculiar properties and abnormal properties. Raman spectral study on the water molecular structure is highly desirable. It obtains the information of molecular vibration and rotation to understand Water is one of the most important and basic materials in living systems which has been extensively studied because of its peculiar properties and abnormal properties. Raman spectral study on the water molecular structure is highly desirable. It obtains the information of molecular vibration and rotation to understand the structure and the interaction of water molecules. The Raman spectra of ice Ih surface of film is obtained in the temperature range of -20 to -190 ℃ at atmospheric pressure. The spectra show that O∶H van der Waals bond and O—H polar-covalent bond shift to higher and lower wave number, respectively. The relationship between Raman shift and temperature is linear, by comparing the slope of different vibration modes to determine the relationship between the expansion and contraction of the bond length, which reveal that the ice Ih density increases with cooling. The results indicate that it is important for hydrogen bond in the process of cooling. Meanwhile, Raman intensity of O—H bond vibration mode and O∶H bond vibration mode occur a mutation at -150 ℃, this results showed that the phase transition of ice Ih-ice Ⅺ (i. e. proton-ordered phase of ice Ih)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1683 (2017)
Study on Modulation Characteristics of Terahertz Wave for Double Optical and Thermal Control
LI Wei-li, MENG Qing-long, HUANG Ren-shuai, LING Fang, and ZHANG Bin
Based on the multi-bands metallic split-ring resonator, the terahertz (THz) wave modulator which has been designed and modulated by optical and thermal control with the application of the photosensitive properties of GaAs material and the thermal induced phase transition properties of VO2 films. In addition, the influeBased on the multi-bands metallic split-ring resonator, the terahertz (THz) wave modulator which has been designed and modulated by optical and thermal control with the application of the photosensitive properties of GaAs material and the thermal induced phase transition properties of VO2 films. In addition, the influence of pump laser fluence and film temperature on the THz wave modulation characteristics has also been studied. The results show that multi-resonances frequency presents blue shift and the resonance strength decreases with the increasing of the pump laser fluence. Moreover, the frequency in the second resonance point (052 THz) is blue shifted by 014 THz and transmission amplitude increases at 50% for the pump laser fluence of 02 μJ·cm-2. Furthermore, the transmission amplitude of the THz wave decreases sharply when the temperature is over the VO2 phase transition temperature, and the transmission amplitude at the peak of the transmission spectrum of 063 THz decreases 455%. Finally, for the case of controlling by pump laser and temperature simultaneously, the resonance frequency also blue shifts and the transmission amplitude of the THz wave at the resonance point increases with the increasing of the pump laser fluence and film temperature. However, the film temperature plays a main role when it is over the VO2 phase transition temperature. The THz wave can be modulated obviously based on the designed THz wave modulator by controlling the light fluence and the film temperature, which can provide useful reference for the design and application of multi-functional THz wave function devices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1687 (2017)
The Spectra Structure Characteristic of Triggered Lightning Channel
ZHANG Hua-ming, ZHANG Yi-jun, L Wei-tao, WANG Hua, and QIAN Yong
The spectra of artificially triggered lightning have been investigated by employing Slit-less Spectrograph in Guangdong region with the peak value of return stroke current was 183 kA, and the duration of return stroke was 45 ms. Through compared the spectrum of the metal and the air portion of the lightning channel, The spectra of artificially triggered lightning have been investigated by employing Slit-less Spectrograph in Guangdong region with the peak value of return stroke current was 183 kA, and the duration of return stroke was 45 ms. Through compared the spectrum of the metal and the air portion of the lightning channel, it was found the spectral line 4253, 4190, 4075, 5179 nm of the metal channel emission had high excitation energy, which had spectrum structure of the strong lightning channel, while the air portion had the weak lightning channel spectral structure. Through compared the relative intensity of the lines, we found the difference of relative strength of the basic lines between the metal portion and air portion is small, but relative intensity of characteristic lines of strong lightning difference was very larger. Through analyzed the excitation energy and other parameters of spectral line of the metal and the air part, the reasons of different spectral structure of the metal and air part were given. When return stroke starting, the leader channel of wire portion had not completely disappeared leading to it was further stimulated by the pulse current of the return stroke. This increased the temperature and density of plasma channel, such that the spectral line of wire portion had completely excitation by higher excitation energy. Compared with air portion, the intensity of 4075, 4190, 4253, 5179 nm had a greater increase. This result in the wire portion of the channel and the air channel had different spectral structure. Through analysis of the temperature and electron density of different channel portion which were calculated according to the information of lightning spectra, the reason why emission luminance of metal portion was different from the air portion is the radiation characteristics between the wire portion and air channel are different..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1692 (2017)
Spectroscopic Characteristics of Atmospheric Pressure Plasma Plume in a Rod-Ring Electrode Geometry
LI Xue-chen, ZHANG Pan-pan, LI Ji-yuan, ZHANG Qi, and BAO Wen-ting
A novel argon plasma jet driven by an alternating current voltage is developed to generate atmospheric pressure non-equilibrium plasma plumes in the upstream and downstream regions of the rod electrode. The novel jet is neither similar to a linear-field jet, nor a cross-field jet. The angle between the electric field aA novel argon plasma jet driven by an alternating current voltage is developed to generate atmospheric pressure non-equilibrium plasma plumes in the upstream and downstream regions of the rod electrode. The novel jet is neither similar to a linear-field jet, nor a cross-field jet. The angle between the electric field and the gas flow direction can be changed easily in this novel jet. By increasing the applied voltage or the angle, the upstream plume length increases and the downstream plume length decreases. With optical and electrical methods, the discharge aspects are investigated and it is found that the discharge pulse number increases with increasing the applied voltage for every voltage cycle. With optical emission spectroscopy, it is found that the spectral lines of Ar and OH can be observed in both of the upstream and downstream plumes. Besides, the spectral lines of N2 can be only observed in the downstream plume. Moreover, the spectral intensity of the downstream plume is slightly higher than that of the upstream plume. Based on the collision-radiation model, the intensity ratio of two spectral lines is investigated to obtain the electron density and the excited electron temperature for the upstream and downstream plumes. Results indicate that the electron densities increase with increasing the applied voltage for the upstream and downstream plumes. The excited electron temperatures of the two plumes also increase with increasing the applied voltage. Moreover, the electron density and the excited electron temperature of the downstream plume are higher than those of the upstream plume under the same applied voltage. Additionally, the gas temperature is also investigated by fitting the spectra of OH radicals for the upstream and downstream plumes. It is also found that the gas temperature of the downstream plume is slightly higher than that of the upstream plume..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1696 (2017)
Study on the Photoluminescence Properties of ZnO Single Crystal
WU Cheng-ling, GUO Jun-hong, YAO Heng-bin, PAN Ling-nan, WANG Fei, WU Wen-qi, JI Tong, and HU Fang-ren
Zinc oxide (ZnO) single crystal is widely considered to be fabricated as a short wavelength light emitting device. In thsi paper temperature-dependent photoluminescence property of the ZnO single crystal was measured with laser irradiation method. Besides, the photoluminescence property was measured with different laseZinc oxide (ZnO) single crystal is widely considered to be fabricated as a short wavelength light emitting device. In thsi paper temperature-dependent photoluminescence property of the ZnO single crystal was measured with laser irradiation method. Besides, the photoluminescence property was measured with different laser irradiation intensity. The results show that the peak of photoluminescence spectrum moves towards the ultraviolet region with the decreasing temperature. This phenomenon can be attributed to the stronger bound exciton combination in the lower temperature. The peak intensity of the photoluminescence is much stronger with stronger laser irradiation. Furthermore, the ZnO single crystal is hexagonal crystal from the X-ray diffraction pattern and Raman spectra. In addition, ZnO demonstrates good crystallization with C axis orientation. Furthermore, this paper has combined Raman scattering experimental and XRD technology to study the structure and energy level property of ZnO single crystal deeply..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1700 (2017)
Adjusting Upconversion Luminous Color of Glass Ceramic with Er3+ Doped by Changing the Size of Crystals
REN Peng, GAO Yuan, YANG Yong, ZHOU Da-cheng, and QIU Jian-bei
Er3+ ion doped glass samples with different doping ratio of NaF and YF3 were prepared with traditional melt cooling technology and all samples were cut into small piece of about 15 mm×15 mm×3 mm for polishing process. The glass transition temperature (Tg) and obvious crystallization peaks were determined by dEr3+ ion doped glass samples with different doping ratio of NaF and YF3 were prepared with traditional melt cooling technology and all samples were cut into small piece of about 15 mm×15 mm×3 mm for polishing process. The glass transition temperature (Tg) and obvious crystallization peaks were determined by differential thermal analysis. The glass samples were heated at 600 ℃ for 2 h. After the thermal treatment, some intensity diffraction peaks correspond to cubic NaYF4 nanocrystals with different size. The size and distribution of the crystallites were determined by XRD, TEM and EDX analysis of glass ceramic samples. From fluorescence spectra and absorption spectra of glass ceramic samples, the color was changed. In the result of crystallization activation energy, it can be determined that glass network structure can be influence by NaF. When the content of NaF is low, integrity of glass network structure is high, and the crystallization activation energy of glass is increased. So the crystallization ability of glass is reduced. From the result of experiments, when the content of NaF is higher, the size of crystals is bigger, the concentration of Er3+ ions in the crystal is higher. And the same time the phenomenon of cross relaxation between Er3+ and Er3+ will be enhanced. It will be caused red emission of Er3+ stronger. Correspondingly, When the content of NaF is reduced, the size of crystals is smaller, the concentration of Er3+ ions in the crystal is lesser. the phenomenon of cross relaxation between Er3+ and Er3+ will be weakened. At this time, the sample will realize green emission. In this paper, the luminous of glass ceramic with Er3+ doped is adjusted successfully by changing the size of crystals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1703 (2017)
Spatio-Temporal Evolution of Air Plasma Plume Driven with a Direct-Current Voltage at Atmospheric Pressure
HAN Yu-hong, JIA Peng-ying, HE Shou-jie, BAO Wen-ting, and ZHAO Zheng
Using a plasma jet to compose two needle electrodes, a brush-shaped plasma plume is generated at atmospheric pressure with ambient air used as working gas. Although a direct-current power supply is used, the discharge shows a pulsed characteristic. The emission pulse frequency keeps constant with changing the gas flow Using a plasma jet to compose two needle electrodes, a brush-shaped plasma plume is generated at atmospheric pressure with ambient air used as working gas. Although a direct-current power supply is used, the discharge shows a pulsed characteristic. The emission pulse frequency keeps constant with changing the gas flow rate, but it increases with the increasing of the output power. The length of the plasma plume increases with the increasing of the gas flow rate and the output power. According to the spatially resolved measurement of light emission (O Ⅰ, 7774 nm), the emission profile is non-symmetric near the outlet. The intensity near the cathode is greater than that near the anode. It tends to be near-symmetric with the location away from the outlet. The plume is analyzed in terms of sustaining voltage, evolution of current, light emission and fast photography of 10 μs. It can be found that the brush-shaped plume is actually a temporal superposition of moving arched discharge filament. As it moves away from the channel outlet, the discharge evolves from arc-shaped filament into a normal glow in one discharge cycle..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1709 (2017)
Direct Evidence of Charge Transfer at Boron Acceptors Being Linked to Phosphorescence in Diamond
LI Jian-jun, FAN Cheng-xing, CHENG You-fa, CHEN Shu-xiang, LI Gui-hua, and TIAN Min-min
An almost colorless diamond observed under the condition of normal light was stimulated under deep ultraviolet light with the DiamondViewTM. It showed a vivid blue fluorescence and strong greenish blue phosphorescence. It indicated that the phosphorescent could last for a few seconds. The 2 803 cm-1absorption peaks of An almost colorless diamond observed under the condition of normal light was stimulated under deep ultraviolet light with the DiamondViewTM. It showed a vivid blue fluorescence and strong greenish blue phosphorescence. It indicated that the phosphorescent could last for a few seconds. The 2 803 cm-1absorption peaks of the infrared spectra only appear during the phosphorescence released. As the phosphorescence disappeared, this peak would be absent.Theorically speaking, the phosphorescence of diamond is related to charge transfer between the boron acceptor and a deep donor, changing the charge state of the boron from compensated to uncompensated and back again. But, too much boron contained in the Type IIb diamond and other defects would disturb to prove the direct correlations between the change in the boron charge state and the emission of phosphorescence. This experiment shows that the 2 803 cm-1 peak immediate data dependency on the phosphorescence gave the most direct evidence that the charge transfer at boron acceptors are foremost linked to phosphorescence in diamond. In essence, the boron acceptor would lose the electron being excited states with the DiamondViewTM and become the uncompensated boron to cause 2 803 cm-1 peak. As the end of excitation from the deep ultraviolet, the uncompensated boron atom of metastable state would throw the excited states electron away. During the excited electrons return to the ground state, the diamond will show luminance as phosphorescence. The wavelength of the emitted photon depends on the distance between the donor and the acceptor, among other factors, for the boron acceptor, common is 500 or/and 660 nm. In this experiment, the phosphorescence band is more likely in the center at 500 nm because of the bluish green phosphorescence. This phenomenon is the first one found as the proof of charging transfer at boron acceptors causing phosphorescence in diamond..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1714 (2017)
Discriminant Analysis of Bamboo Leaf Types with NIR Coupled with Characteristic Wavelengths
CHU Bing-quan, ZHAO Yan-ru, and HE Yong
Bamboo leaves are rich in many kinds of biological active components such as flavonoid, phenolic acid and polysaccharide, which have demonstrated good effects of anti-oxidant, blood lipid regulation, anti-cancer, cardiovascular and cerebrovascular protection etc. However, the content of active constituents exhibits greBamboo leaves are rich in many kinds of biological active components such as flavonoid, phenolic acid and polysaccharide, which have demonstrated good effects of anti-oxidant, blood lipid regulation, anti-cancer, cardiovascular and cerebrovascular protection etc. However, the content of active constituents exhibits great differences among different bamboo species. The traditional identification of bamboo species is mainly based on the observation of bamboo leaf size, bamboo texture and branching height etc. which has the disadvantages of low efficiency and high error rate. Therefore, to distinguish the varieties of bamboo with a rapid and accurate method is an important task in the development and utilization of bamboo leaves. A near-infrared (900～1 700 nm) hyperspectral technique was used to identify 12 bamboo species from different regions of China. Principal component analysis (PCA) was applied to make the cluster analysis. PCA X-loading (XL) and Random Frog (RF) algorithm was chosen to extract spectral feature and 6 characteristic wavelengths (931, 945, 1 217, 1 318, 1 473 and 1 653 nm) and 12 characteristic wavelengths (1 052, 1 140, 1 163, 1 177, 1 180, 1 193, 1 230, 1 241, 1 477, 1 483, 1 629 and 1 649 nm) were selected respectively. Then, the spectra based on the selected wavelengths were set as the input values of Least Squares-Support Vector Machine (LS-SVM) model to perform the discriminant analysis. At last, the properties of the three LS-SVM models were evaluated with Receiver Operating Characteristic curve (ROC curve). Results showed that (1) in the three LS-SVM models, the recognition rate of full band, XL algorithm and RF algorithm were 9917%, 9583% and 9583% respectively, (2) the area under the curve (AUC) in ROC curve were all reach over 098. In conclusion, the bamboo leaves from different regions could be identified by near-infrared hyperspectral technique combined with chemometrics methods, which provided a theoretical foundation for efficient utilization of bamboo leaves..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1718 (2017)
Review of Monitoring Petroleum-Hydrocarbon Contaminated Soils with Visible and Near-Infrared Spectroscopy
CHEN Zhi-li, YIN Wen-qi, LIU Hong-tao, LIU Qiang, and YANG Yi
The leaks of petroleum and petroleum products can cause serious soil pollution. Conventional methods for monitoring petroleum-hydrocarbon leaks are time-consuming and poor in portability, which is difficult to meet the requirements of diagnosing large-area soil pollution and digital soil mapping. Visible and near-infraThe leaks of petroleum and petroleum products can cause serious soil pollution. Conventional methods for monitoring petroleum-hydrocarbon leaks are time-consuming and poor in portability, which is difficult to meet the requirements of diagnosing large-area soil pollution and digital soil mapping. Visible and near-infrared spectroscopy (Vis-NIRS) is a low-cost and non-destructive method that allows rapid and convenient measurements, which is the most potential means for rapid acquisition of soil information as the trend of future research and development. This technology has been widely uesd for decades to monitor soil properties. However, in the field of monitoring soil contaminated with petroleum-hyrdocarbons, the research is still in its infancy and the model of retrieving petroleum-hydrocarbon content is a difficult problem. In addition, the current research achievement has seldom been summarized. In the present paper, the author discussed the feasibility of the monitoring for soil-petroleum contamination with visible and near-infrared spectroscopy and summarized the latest research progress in spectral diagnostic bands, prediction models and spectral libraries of contaminated soils in recent years. Besides, the existing shortcomings are analyzed and future research direction is put forward. It is pointed out that in the future, strengthen four aspects research for several kinds of petroleum-hydrocarbon mixture samples, general petroleum-hydrocarbon prediction model, field spectral measurement experiment and imaging spectroscopy technology, so as to provide reference for further research on soil petroleum-hydrocarbon pollution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1723 (2017)
Study on Preparation Mechanism of Ce-La/TiO2 Composites and Photocatalytic-Mositure-Heat Properties Based on FTIR and UV-Vis Spectra
SHANG Jian-li, ZONG Zhi-fang, SONG Dong-yi, and TIAN Ye
To obtain multifunctional composites which had temperature-humidity properties and photocatalytic degradation ability to harmful substances, Ce-La/TiO2 hollow microspheres were prepared with Sol-Gel method. Then taking the Ce-La/TiO2 hollow microspheres as the carrier materials, the phase change materials—decanoic acidTo obtain multifunctional composites which had temperature-humidity properties and photocatalytic degradation ability to harmful substances, Ce-La/TiO2 hollow microspheres were prepared with Sol-Gel method. Then taking the Ce-La/TiO2 hollow microspheres as the carrier materials, the phase change materials—decanoic acid-palmitic acid was filled in Ce-La/TiO2 hollow microspheres’ cavities with vacuum absorption method to prepare Ce-La/TiO2 composites which had photocatalytic-mositure-heat properties. The materials of the main step of Ce-La/TiO2 composites were characterized with FTIR to study the establishment of SiO2 template, the bridging role of surfactant polyvinylpyrrolidone (PVP), the effect of filled decanoic acid-palmitic acid into Ce- La/TiO2 hollow microspheres. The photoresponisve of Ce-La/TiO2 composites was characterized by UV-Vis to study the effect of Ce-La doping to the TiO2 hollow microspheres’ light response ability. Further more, the microstructure of Ce-La/TiO2 composites was characterized with SEM to clarify the Ce-La/TiO2 composites preparation mechanism. The results show that, alkali environment which is provided by ammonium hydroxide is good for condensation reaction of tetraethoxysilane (C8H20O4Si), accelerating generate Si—O—Si groups at 78000 cm-1 to build SiO2 skeleton form kernel as the template to support the TiO2 wall materials. Adding PVP can generate —C—N— groups at 1 03500 cm-1, which is benefit for TiO2 attached to the surface of SiO2. Calcinate Ce-La/TiO2 hollow microspheres at high temperature can effectively remove PVP to avoid impurity ions into the composite system. Ce-La dopping makes the Ce-La/TiO2 composites’ absorption edge red shift, which is beneficial in enhancing the photocatalytic degradation ability under visible light. It also enhances the hydroscopicity of Ce-La/TiO2 composites due to —OH groups at 1 63000 cm-1. Decanoic acid-palmitic acid is fully filled in Ce-La/TiO2 hollow microspheres’ cavities, there is not much change in characteristic absorption peak of each component so the fundamental characteristics of each component could remain unchanged..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1728 (2017)
Variable Selection Method of NIR Spectroscopy Based on Least Angle Regression and GA-PLS
YAN Sheng-ke, YANG Hui-hua, HU Bai-chao, REN Cha0-chao, and LiU Zhen-bing
Near infrared (NIR) spectra usually have many wavelength variables. Direct or indirect variable selection is crucial to improve the stability and prediction performance of a model. Least angle regression (LAR) is a relatively new and efficient machine learning algorithm for regression analysis and variable selection. BNear infrared (NIR) spectra usually have many wavelength variables. Direct or indirect variable selection is crucial to improve the stability and prediction performance of a model. Least angle regression (LAR) is a relatively new and efficient machine learning algorithm for regression analysis and variable selection. By combining LAR and genetic algorithm-partial least square (GA-PLS) algorithm, a wavelength selection method is proposed in this paper for spectral modeling applications, which can effectively screen a few wavelength points. Firstly, LAR is used to eliminate the multiple-collinearity among variables in the full spectrum region and get a reduced set of features, then GA-PLS is introduced to select the variables from the reduced set of features to achieve the purpose of further dimension reduction. In order to verify the validity of it, the method is carried out by making regression analysis on the NIR spectroscopy of tablets and gasoline. The pre-processing results of original spectra are used to select the variables and have modeled on the content of active ingredients (Tablets) and C10 (Gasoline). As a result, the optimal number of variables are just 7 in both of applications, and the predictive decision coefficient (R2p) reached 0933 9 and 0951 9 respectively. Moreover, by comparing with the full spectrum, elimination of uninformative variables (UVE) and successive projection algorithm (SPA) model, the result shows that this method needs less wavelength points and have more excellent in R2p and root mean square error of predication (RMSEP). Therefore, LAR combined with GA-PLS not only can picks out information variables from NIR spectroscopy to reduce the variable number for modeling and improve the prediction accuracy, but also has a better interpretation of the model. The method can provide as effective wavelength selection tool for designing of special spectrometer in particular area..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1733 (2017)
Study on the CL and FTIR Spectra of the Alluvial Diamond from Western Yangtze Craton and Its Significance in the Growth Rate Analysis of the Diamond
YANG Zhi-jun, ZHOU Wen-xiu, ZENG Xuan, HUANG Shan-shan, LI Xiao-xiao, and CHEN Yao-ming
In order to provide scientific clues for reconstructing effectively the process of natural diamond growth, the diamond sample from the western Yangtze Craton is studied with CL and FTIR spectra. In the paper, the micro-section of growth of the sample was defined with CL spectra, while the growth time of each diamond seIn order to provide scientific clues for reconstructing effectively the process of natural diamond growth, the diamond sample from the western Yangtze Craton is studied with CL and FTIR spectra. In the paper, the micro-section of growth of the sample was defined with CL spectra, while the growth time of each diamond section was determined with FTIR spectra; besides, the growth rate of the diamond section was calculated. The results of CL and FTIR spectra analysis of the sample show that there are early CL growth zonings which are terrace and jagged straight zonings and late CLre-growth zonings in the diamond. The concentration of nitrogen varies greatly from 4788~32189 μg·g-1 in the diamond which is type IaAB. The minimal crystalline temperature of the sample is 1 490 K. The residence time of the diamond section in the mantle depending on the positions varies greatly from 0264~46 Ga. The growth rate of the diamond section depending on the positions is 926~5 21818 μm·Ga-1. Furthermore, the growth of the different diamond section is heterogeneous with preferential direction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1739 (2017)
Research on Steaming Procedure of Aconite Root with FTIR and Two-Dimensional IR Correlation Spectroscopy
WU Zhi-sheng, LIU Xiao-na, TAN Peng, PEI Yan-ling, DAI Xing-xing, and QIAO Yan-jiang
Fourier transform infrared spectroscopy (FTIR), second derivative infrared spectroscopy, and two-dimensional correlation infrared spectroscopy (2D-IR) were used to study the steaming procedure of aconite tuber. The results showed that samples with steaming procedures were similar to each other in one-dimensional IR speFourier transform infrared spectroscopy (FTIR), second derivative infrared spectroscopy, and two-dimensional correlation infrared spectroscopy (2D-IR) were used to study the steaming procedure of aconite tuber. The results showed that samples with steaming procedures were similar to each other in one-dimensional IR spectra but different in 2D-IR spectra. The FTIR spectra combined with second derivative infrared spectroscopy of different samples during boiling procedure present characteristic peaks at 1 63487 cm-1 (CO), 1 60318, 1 57158 cm-1, 1 48509, 1 41308 cm-1 (vibration of phenyl framework) and 1 15373, 1 08184, 1 02135 cm-1 (C—O) respectively. There were two conspicuous time sequences in two dimensional infrared correlation spectroscopy of autopeaks intensity. Since, the intensity of autopeaks was relatively high during 2～3 and 8～9 h. The function of FTIR and 2D-IR for analysis of the alkaloid from aconite root attributed high speed and high efficiency. The results were reliable and valuable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1745 (2017)
Research on Rapid Determination of Diesel Cetane with Near-Infrared Spectroscopy
ZHAN Bai-shao, YANG Jian-guo, LIU Xue-mei, and ZHANG Hai-liang
The rapid determination of the value of cetane is important for the determination of the quality of diesel. To remove the absolute noises of the spectra, the extracted 381 absorbance spectra were preprocessed with Savitzky-Golay smoothing (SG), EMD, and Wavelet Transform (WT) methods. The preprocessed spectra were thenThe rapid determination of the value of cetane is important for the determination of the quality of diesel. To remove the absolute noises of the spectra, the extracted 381 absorbance spectra were preprocessed with Savitzky-Golay smoothing (SG), EMD, and Wavelet Transform (WT) methods. The preprocessed spectra were then used to select sensitive wavelengths with competitive adaptive reweighted sampling (CARS). LS-SVM were applied to build models with the selected 12 wavelength variables. The overall results showed that the LS-SVM models with the selected wavelengths based on WT preprocessed spectra obtained the best results with the determination coefficient (r2) and RMSEP were 0723 and 1878% for prediction set. The results indicated that it was feasible to use NIR with characteristic wavelengths which were obtained with CARS variable selection method, combined with LS-SVM calibration could apply for the rapid and accurate determination of diesel cetane. Moreover, this study laid a foundation for further implementation of online analysis of cetane and rapid determination of other diesel quality parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1749 (2017)
Qualitative and Quantitative Analysis of Paris polyphylla var. yunnanensis in Different Harvest Times with Infrared Spectroscopy Combined with Chemometrics
WU Zhe, ZHANG Ji, JIN Hang, WANG Yuan-zhong, and ZHANG Jin-yu
In order to provide a scientific basis tor find out the best harvest time. Fourier transform infrared (FT-IR) spectroscopy combined with partial least squares discriminant analysis (PLS-DA) and partial least squares regression (PLSR) were used for the identification and evaluation of Paris polyphylla var. yunnanensis fIn order to provide a scientific basis tor find out the best harvest time. Fourier transform infrared (FT-IR) spectroscopy combined with partial least squares discriminant analysis (PLS-DA) and partial least squares regression (PLSR) were used for the identification and evaluation of Paris polyphylla var. yunnanensis from different harvest times. Infrared spectra of 46 samples from different harvest times were collected. The original spectra were pretreated with automatic baseline correction, ordinate normalization, automatic smoothing and wavelet denosing prior to PLS-DA. The contents of polyphyllin Ⅰ, Ⅱ, Ⅵ and Ⅶ were determined with ultra performance liquid chromatography (UPLC). The PLSR model was established combining the spectral data with the reference data performed by UPLC data for evaluating the quality of polyphyllin Ⅰ, Ⅱ, Ⅵ and Ⅶ after the preprocessing of automatic baseline correction, ordinate normalization, automatic smoothing, first derivative and Orthogonal signal correction (OSC). Results showed that: (1) The main absorptions of the original spectra were in the ranges of 950~700, 1 200~950, 1 800~1 500 and 2 800~3 500 cm-1. (2) The PLS-DA score plot could accurately distinguish P. polyphylla var. yunnanensis from different harvest times. (3) According to the UPLC data, it was found that the total content of polyphyllin Ⅰ, Ⅱ, Ⅵ and Ⅶ got a fold increase, then elicited a decline, and finally showed a slow upward trend with the growth period. (4)There was no significant differences between the predicted value based on quantitative model and measured value with UPLC, and the effect of the model was good. FT-IR spectroscopy combined with chemometrics could clearly distinguish P. polyphylla var. yunnanensis from different harvest times and reach a fast prediction for the content of polyphyllin. Furthermore, it could provide a method for distinguishing and forecasting polyphyllin and a theoretical basis for best harvest time of P. polyphylla var. yunnanensis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1754 (2017)
On-Line Noninvasive Prediction of Cholesterol Level of Fresh Pork within NIR Medium Wavelength Region with Portable Near-Infrared Spectrometer
WANG Hui, TIAN Han-you, ZHANG Shun-liang, ZHANG Hao, ZHAO Bing, LI Jia-peng, and QIAO Xiao-ling
Portable near infrared spectrometer was applied to collect 320 pieces of fresh pork spectral information in NIR medium wavelength region. Prediction models of fresh pork cholesterol level with NIR spectroscopy were established through partial least squares method combined with different spectroscopy preprocessing methoPortable near infrared spectrometer was applied to collect 320 pieces of fresh pork spectral information in NIR medium wavelength region. Prediction models of fresh pork cholesterol level with NIR spectroscopy were established through partial least squares method combined with different spectroscopy preprocessing methods. The effects of outlier samples elimination and combination of different preprocessing methods on the prediction model performance were discussed. The result showed that the optimum prediction model of fresh pork cholesterol level was achieved with the application of two optimization procedures, eliminating outliers twice and combination of SG first order derivative, SG smoothing and orthogonal signal correction, and the relevant parameters as follows: Rc=0913 7, SEC=2560 7, Rp=0656 7, SEP=4985 5, MF=4, RPD=2503 2, RSEP=8625 4%, SEP/SEC=1946 8, which indicated the reliability, resolution capacity and prediction accuracy of this model in NIR medium wavelength region were acceptable. The robustness of optimal prediction model could be further improved by adding more representative and typical sample of different cholesterol level range into the calibration set. Paired-samples t-test showed non-significance between the predicted value and reference value (p＞005), and the total prediction accuracy of testing samples was 625%, and partial prediction accuracy was 917% in cholesterol range of 50～70 mg·(100 g)-1, which showed that this model could be applied into on-line rapid preliminary quantitative analysis of cholesterol level of fresh pork. In this research it was the first time that portable near-infrared spectrometer was applied into the analysis and detection of cholesterol level of fresh pork products within NIR medium wavelength region, and with further study and improvement, the prediction model could also be applied to raw material classification, quality and process control, random inspection of commercially available meat and meat products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1759 (2017)
Infrared Spectroscopy Quantitative Detection Method Based on Second Order Derivative Spectrum and Characteristic Absorption Window
LIU Xi-yang, GAO Nan, DU Zhen-hui, LI Jin-yi, CHEN Chao, and ZHANG Zong-hua
In the field of detection, infrared spectroscopy has been widely used to quantitatively detect components in liquid, solid and gas mixtures . Aiming at the problems of complicated calculation process, background and noise interference, and spectrum overlap from multi components in infrared spectroscopy quantitative detIn the field of detection, infrared spectroscopy has been widely used to quantitatively detect components in liquid, solid and gas mixtures . Aiming at the problems of complicated calculation process, background and noise interference, and spectrum overlap from multi components in infrared spectroscopy quantitative detection. On the one hand, a method based on second order derivative spectrum for the original absorption line was used to quantitative detection. The background and noise interference were removed in second order derivative spectrum, and the aliasing absorption peaks were distinguished to a certain extent. In the process of obtaining second order derivative line, Savitzky-Golay filter was used for smoothing filtering the spectrum. The optimal filter parameters were selected according to the spectral line frequency characteristics, which makes up the lack of the standardized methods in filtering parameters selecting. On the other hand, the characteristic absorption windows in term of the absorption distribution of corresponding components were applied to both original absorption line and second order derivative spectrum. The characteristic absorption region of more importance in the concentration calculation was extracted, so as to eliminate the interference of background, noise and other components in the non absorption region. The multi components mixtures of propane, propylene and methylbenzene were used as samples for quantitative detection with both methods mentioned above together with the method using original absorption lines. Then a comparison of the results by different method was analyzed. The experiment results show that the quantitative detection methods by using the second order derivative spectrum and the characteristic absorption window can achieve higher accuracy with relative error less than 5%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1765 (2017)
Rapid Determination of Geniposide in Gardenia Jasminoids Ellis in Different Preparations Methods with NIRS
ZHONG Yong-cui, YANG Li-wei, QIU Yun-qi, WANG Shu-mei, and LIANG Sheng-wang
In the study, 96 samples of Gardenia jasminoids Ellis in different preparation methods were collected, including model building with 83 samples and validation with 13 samples. The reference analysis was performed using a HPLC method to determine the content of geniposide. Method for the quantification of geniposide in In the study, 96 samples of Gardenia jasminoids Ellis in different preparation methods were collected, including model building with 83 samples and validation with 13 samples. The reference analysis was performed using a HPLC method to determine the content of geniposide. Method for the quantification of geniposide in Gardenia jasminoids Ellis in different preparation methods with NIRS are studied by integral sphere of diffuse reflection. The spectral regions from 8 660 to 7 500 cm-1, from 6 650 to 5 600 cm-1 and from 4 900 to 4 000 cm-1 were selected for the calculation of the quantitative model. The spectral data of geniposide were processed using the second derivative and standard normal variate transformation (SNV). The quantitative model of geniposide was built based on partial least squares (PLS) method with main components (8) with 83 samples of Gardenia jasminoids Ellis. Finally, validation of the quantitative model was accomplished with 13 samples of Gardenia jasminoids Ellis in different preparation methods. The correlation coefficients(R2), the root meat square error of calibration(RMSEC), the root meat square error of prediction(RMSEP), the root meat square error of cross validation(RMSECV) and RMSEP/RMSEC of the calibration model in geniposide were 0992 85, 0240, 0254, 0386 91 and 106. The ratio of standard deviation of the validation set to standard error of prediction (RPD) from model validation was 881, the range of absolute deviation was -039%~023%. The model established has good predictability. Besides, experimental conditions also have impact on the testing results, including scan frequency, amount of measured sample, the number of replications and resolution determined by correlation coefficient method. What’s more, using first derivative spectra, second derivative spectra and near-infrared spectra of geniposide to confirm the spectral regions can distinct the spectral regions according to temperature differences humidity and moisture content. For the first time, a quantitative model with NIRS is established for rapid determination of geniposide in Gardenia jasminoids Ellis with different preparation methods. The quantitative model of geniposide was stable and reliable, which can rapidly and accurately determine the content of geniposide in Gardenia jasminoids Ellis with different preparation methods with NIRS simultaneously..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1771 (2017)
Design of Rapid Detection System for Urotropine in Food Based on SERS
LI Wei, FAN Xian-guang, WANG Xin, TANG Ming, QUE Jing, HE Jian, and ZUO Yong
Based on surface enhanced Raman spectroscopy (SERS) technology, the detection system for rapid fild determination of urotropine in food is proposed. The detecting system consists of multifunctional pretreating module, Roman optical module and embedded master control module. It completed the pretreatment of sample, the Based on surface enhanced Raman spectroscopy (SERS) technology, the detection system for rapid fild determination of urotropine in food is proposed. The detecting system consists of multifunctional pretreating module, Roman optical module and embedded master control module. It completed the pretreatment of sample, the generation, collection and transmission of the Raman spectral data. The multifunctional pretreating module integrate centrifuge, ultrasound and volatile functions all together, reducing the equipments used in the pretreatment experiment. Besides, it is portable and convenient for operation. The Roman optical module we designed embodies the probe of Raman spectrometer and monochromator, and the numerical aperture of the aspherical lens we used in the optical system of the probe was 06. Besides, the monochromator was designed based on Asymmetrical crossed Czerny-Turner structure. The hardware part of the embedded master control module is made up of ARM and FPGA, and its peripheral circuits. The software part of the module is made up of real time operation system μC/OS-Ⅲ, graphics library emWin, file system FatFs and various types of equipment components. Thus, accomplished the collection, transmission and calculation of the Raman spectral data from CCD. The liquid colloidal gold nanoparticle (LCP-1) was used in the detection experiments of urotropine, while the characteristic peaks at 1 047 cm-1 was chosen as the identity information of urotropine. The result of detection experiments shows that the system has the ability to identify the urotropine accurately, the detection limit of urotropine standards was 001 mg·L-1, with detection limit of urotropine in yuba and rice-noodle was 05 mg·L-1. Besides, the testing time was less than 20 minutes,which meets the requirements for rapid field determination of urotropine in food．.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1778 (2017)
Raman Spectroscopy in Ovarian Cancer Diagnostics
LU Shao-yu, WANG Shu-guang, LIU Wen-jing, and JING Chuan-yong
Ovarian cancer is the most lethal gynecologic malignancy which has high morbidity. Currently, histopathology, ultrasonic and CA125 detecting are the main diagnostic techniques for ovarian tissues. Though these methods have significantly increased the survival rate of patients with ovarian cancer, there is still a challOvarian cancer is the most lethal gynecologic malignancy which has high morbidity. Currently, histopathology, ultrasonic and CA125 detecting are the main diagnostic techniques for ovarian tissues. Though these methods have significantly increased the survival rate of patients with ovarian cancer, there is still a challenge in terms of distinguishing adenoma and early adenocarcinomas from benign hyperplastic polyps. So Raman spectroscopy was applied as a sensitive diagnostic alternative to identify pathologic changes (e. g., dysplasia) in ovarian tissue at the molecular level, using partial least-squares-discriminant analysis (PLS-DA) model. The subtle Raman variations among normal and cancerous ovarian tissues are associated with the transformation of cancerous tissues. Multivariate statistical method of partial least-squares-discriminant analysis (PLS-DA), together with the leave-one-patient-out cross-validation, is employed to build the discrimination model. In this research, we choose the corresponding LV (latent variables) numbers as 5, which has the lowest CV classification error. In this way, there is 3961% information of functional group captured. In addition, p-value is also calculated to compare and it is known that the first LV (p=107×10-13) has the most significant effect. Meanwhile, through the model we can know Raman spectroscopy associated with PLS-DA modeling provides highly specific signatures of various biomolecules, rendering a sensitivity of 862%, a specificity of 854%, and collectively a diagnostic accuracy of 852%. The results demonstrate that Raman spectroscopy can be used with PLS-DA model as a sensitive diagnostic alternative to identify pathologic changes in ovarian at the molecular level..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1784 (2017)
Surface-Enhanced Raman Spectroscopy for Rapid Detection of Uric Acid in the Urine
ZHENG Bin, WEN Bao-ying, SU Li-zhong, ZHANG Hua, and LI Jian-feng
Surface-enhanced Raman spectroscopy (SERS) is a fingerprint technique with ultra-high surface sensitivity down to single-molecule level. It can be used for specific, fast and nondestructive detection of trace amounts of molecules, which has been widely applied in various fields, such as life sciences, electrochemistry,Surface-enhanced Raman spectroscopy (SERS) is a fingerprint technique with ultra-high surface sensitivity down to single-molecule level. It can be used for specific, fast and nondestructive detection of trace amounts of molecules, which has been widely applied in various fields, such as life sciences, electrochemistry, environmental safety and even our daily life. Herein, highly uniform Au nanoparticles with tunable sizes are prepared via a seed growth method. They have been used as SERS substrates for detection of uric acid. Size dependent SERS enhancements have been found for the Au nanoparticles, and the enhancements increase with the particle size. Au nanoparticles with size of 150 nm are the optimized substrate for the detection of uric acid, when the laser with wavelength of 638 nm is used as exciting light. The detection limit of uric acid is 001 mmol·L-1. It has also been found that Au nanoparticles could be used for the quantitative detection of uric acid. The result shows that there is a linear relationship between the Raman intensity of the peak at 640 cm-1 and the concentrations of uric acid in the range of 001～05 mmol·L-1. Therefore, this method can be used for rapid detection of real samples (normal human urine). It is not affected by the interference of other components in urine, thus, it can realize the rapid determination of uric acid in human urine. This work greatly expands the clinical application of surface enhanced Raman spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1789 (2017)
Characterization of Polycyclic Aromatic Hydrocarbons with Time-Resolved Fluorescence
XIAO Xue, ZHAO Nan-jing, YU Shao-hui, MA Ming-jun, YANG Rui-fang, YIN Gao-fang, DUAN Jing-bo, DONG Yun-sheng, LIU Jian-guo, and LIU Wen-qing
Characteristic time-resolved fluorescence spectroscopy of polycyclic aromatic hydrocarbons were studied. Stimulated Raman scattering (SRS) was used to generate several excitation wavelengths, 289nm was selected as excitation source in this paper. Delay characterization and gate characterization were researched. AccordiCharacteristic time-resolved fluorescence spectroscopy of polycyclic aromatic hydrocarbons were studied. Stimulated Raman scattering (SRS) was used to generate several excitation wavelengths, 289nm was selected as excitation source in this paper. Delay characterization and gate characterization were researched. According to the decay relationship between fluorescence intensity and delay time, fluorescence lifetime of phenanthrene, fluoranthene, fluorene, pyrene were obtained, which were 370, 327, 109, 1470 ns respectively. Different fluorescent substances have specific fluorescence spectral characteristics, the study of time-resolved fluorescence spectral of polycyclic aromatic hydrocarbons can provide the diagnosis basis for different polycyclic aromatic hydrocarbons in complex water environment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1793 (2017)
Instantaneous Imaging of Reaction Zone and CH3 Radicals in Flames
LI Xiao-feng, YAN Bei-bei, ZHANG Da-yuan, LI Hong, LI Bo, CHEN Guan-yi, and LI Zhong-shan
Online instantaneous two-dimensional imaging of reaction zone and different intermediate species in flames are important and fundamental in the research of turbulence combustion. In methane/air premixed flames, the instantaneous imaging of flame reaction zone is achieved using laser photodissociation-induced fluorescenOnline instantaneous two-dimensional imaging of reaction zone and different intermediate species in flames are important and fundamental in the research of turbulence combustion. In methane/air premixed flames, the instantaneous imaging of flame reaction zone is achieved using laser photodissociation-induced fluorescence technique with the 5th harmonic (2128 nm) of an Nd∶YAG laser as excitation source.The online instantaneous imaging of CH3 radicals was accomplished for the first time with this technique. The advantage of this technique was analyzed over other typical PLIF techniques in terms of visualization of flame reaction zone. The influences of other combustion intermediates and flame equivalence ratio to the single-shot imagining of CH3 were studied, and the application range of the technique was also discussed. The result shows that single shot imaging of reaction zones in our measurement with a signal-to-noise ratio (SNR) of 8. Single shot imaging of CH3 has better SNR by LPIF in premixed methane/air flames with the equivalence ratio from 10 to 14, or when the concentration of CH3 is higher than 9×1015 molecules·cm-3. The results provide very important information for the application of this technology in power machinery and other field..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1799 (2017)
Preparation and Spectroscopic Characteristics of CaAl2Si2O8∶Eu, Ce, Tb Fluorescent Material
XU Dan-zhi, FENG Jing, YANG Xiao-yun, ZU En-dong, CUI Xiao-ying, LIN Jin-chang, and DONG Kun
CaAl2Si2O8∶Eu, Ce, Tb fluorescent material were synthesized with high temperature solid phase method.The fluorescent materials were characterized with fluorescence spectroscopy (PL), Raman spectroscopy (Raman) and X-ray diffraction (XRD).The phase compositions of the samples were studied with XRD. It was shown that theCaAl2Si2O8∶Eu, Ce, Tb fluorescent material were synthesized with high temperature solid phase method.The fluorescent materials were characterized with fluorescence spectroscopy (PL), Raman spectroscopy (Raman) and X-ray diffraction (XRD).The phase compositions of the samples were studied with XRD. It was shown that the Eu2+ substitution of Ca2+ did not induce the changes of the structure of the matrix. Raman spectroscopy confirmed the presence of silicon-oxygen tetrahedron and aluminum oxygen tetrahedrons. Raman spectra also confirmed that the amount of Eu2+ substitution Ca2+ was related to the degree of crystal morphology distortion. PL spectra of the samples shows that the emission peak at 325 nm wavelength excitation, the emission peak of the sample was shown to be a strong emission peak at 426 nm (blue region) and a weak emission peak at 541 nm (green region). The emission peaks can be fitted with Gaussian to three fitting peaks at 393, 419 and 474 nm. After combining the analysis and comparison, and ultimately determine when Eu∶Ce∶Tb=1∶1∶1. 5 the sample shows the strongest fluorescence intensity. CIE chromaticity diagram shows that the samples are emitting blue fluorescence. The material has good color rendering, color temperature is low, which is a kind of suitable blue fluorescent LED material with ultraviolet and near ultraviolet excitation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1804 (2017)
The Analysis of Vegetation Spectra Based on Multi-Band Lidar
FENG Ming-bo, NIU Zheng, and SUN Gang
Multi-band Lidar is a new means to obtain spectra. It is different from the traditional spectrometer which can only get spectra in the two-dimensional level. The multi-band Lidar based on the super-continuum spectrum laser light, uses the penetrability and high concentration of laser and gets the spectra of vegetation Multi-band Lidar is a new means to obtain spectra. It is different from the traditional spectrometer which can only get spectra in the two-dimensional level. The multi-band Lidar based on the super-continuum spectrum laser light, uses the penetrability and high concentration of laser and gets the spectra of vegetation in vertical direction, relying on the grating instrument system. With it the spectral distribution of vegetation in the three-dimensional level can be obtained. In this paper, 32-band Lidar is applied. Firstly, the spectra obtained with 32-band Lidar and ASD spectrometer in a darkroom are compared, which proves that they have the same shape, accurately indicating the reflection characteristics of vegetation from 458 to 865 nm. Then with the analysis of the correlations of spectral index and chlorophyll content, it is found that the fitting relations between the spectral indices and chlorophyll content acquire nice effect and there is highly significant correlation between the Modified Simple Ratio (MSR) based on multi-band Lidar spectra and chlorophyll content, the determination coefficient (R2) is 0780 2 and the RMSE is only 0508 1. Finally, with multi-band Lidar, the spectra in the vertical direction and the three-dimensional point cloud distribution of spectra are obtained via multiple scanning. Based on the optimal fitting equation between MSR and chlorophyll content, three-dimensional distribution of chlorophyll content is gotten..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1809 (2017)
Interaction between Low Molecular Weight Chitosan Derivatives and Bovine Serum Album
HUANG Yan, LIU Yun, ZHANG Qi, JIA Chun-man, HUA Ming-qing, CAO Juan, and ZHU Wei-hua
The effect between biocompatible low molecular weight chitosan derivatives as the delivery carrier of active pharmaceuticals bovine serum album (BSA) was studied. Three derivatives of low molecular weight chitosan with 20 degree of polymerization (NLCS20) and narrow molecular weight distribution including N-maleoyl-NLCThe effect between biocompatible low molecular weight chitosan derivatives as the delivery carrier of active pharmaceuticals bovine serum album (BSA) was studied. Three derivatives of low molecular weight chitosan with 20 degree of polymerization (NLCS20) and narrow molecular weight distribution including N-maleoyl-NLCS20, N-carboxymethyl-NLCS20 and N-succinyl-NLCS20 were synthesized. The effect between NLCS20 derivatives and BSA was studied with UV spectrum, fluorescence spectrum and isothermal titration calorimetry (ITC). The results showed that the conformation and activity of BSA did not change a lot in the microenvironment of NLCS20 derivatives solution. The process was exothermic and spontaneous. The main binding force was hydrogen bond and hydrophobic interaction. It was concluded that low molecular weight derivatives are likely to be delivery carriers of hydrophilic drugs such as active protein or poly amino acid..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1814 (2017)
Representation of Functional Group and Thermal Variation Behavior of Jet in Fushun Liaoning
XING Ying-ying
All samples tested are extracted from West Open-pit Coal Mine of Fushun(WOPCM), Liaoning. With FTIR with reflection testing method and varied temperature, representation of functional group and thermal variation behavior of jet are analyzed. The result shows that: representation of FTIR and ATR-FTIR of Fushun jet conceAll samples tested are extracted from West Open-pit Coal Mine of Fushun(WOPCM), Liaoning. With FTIR with reflection testing method and varied temperature, representation of functional group and thermal variation behavior of jet are analyzed. The result shows that: representation of FTIR and ATR-FTIR of Fushun jet concentrates mainly cover two areas: 2 900~2 800 and 1 600~1 200 cm-1; the absorption spectrum band of jet caused with stretching vibration ofν(CH2) becomes lower and lower along with the temperature rise in the process of low-temperature oxidation while the absorption spectrum band caused by stretching vibration ofν（CO） becomes higher and higher. Due to oxidation in the process of petrifaction, alkane in jet becomes less and less while the oxygen-containing functional group keeps on increasing, thus, the formation environment of jet consists anaerobic reduction environment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1819 (2017)
Study on Interaction between Alliin and Bovine and Hunman Serum Albumin with Spectrometry
MA Xue-hong, SONG Bai-ling, XIAO Wen-jun, GENG Jing, LI Xin-xia, and CHEN Jian
The interaction between alliin and bovine serum albumin(BSA) and human serum albumin(HSA) was studied under a pH74 Tris-HCl buffer system with multiple spectroscopic techniques．The study took 280 nm as the excitation wavelength to scan the range of 300~500 nm of fluorescence emission spectrum by using fluorescence speThe interaction between alliin and bovine serum albumin(BSA) and human serum albumin(HSA) was studied under a pH74 Tris-HCl buffer system with multiple spectroscopic techniques．The study took 280 nm as the excitation wavelength to scan the range of 300~500 nm of fluorescence emission spectrum by using fluorescence spectrophotometer while setting wavelength differential as Δλ=15 nm and Δλ=60 nm to scan synchronous fluorescence spectra. The fluorescence quenching data were analyzed by applying Stern-Volmer equation and Line weaver-Burk equation. It is shown that Alliin was effective in quenching BSA and HSA fluorescence. The binding constant obtained of alliin and BSA was 981×102 L·mol-1 at 298 K and 615×102 L·mol-1 at 310 K. The binding constant obtained of alliin and HSA was 221×102 L·mol-1 at 298 K and 684×102 L·mol-1 at 310 K. The thermodynamic parameters, ΔH calculated by using Gibbs-Helmholtz Equation of the reaction of alliin and BSA is -299 kJ·mol-1 and ΔS is 430 J·mol-1·K-1 and ΔG is -171 kJ·mol-1 at 298 K. ΔH of the reaction of alliin and HSA is 723 kJ·mol-1 and ΔS is 288 J·mol-1·K-1 and ΔG is -134 kJ·mol-1 at 298 K. The main types of binding force of Alliin-BSA were hydrophobic interaction and the sorts of binding force of Alliin-HSA were electrostatic action. The results of synchronous fluorescence spectra showed that alliin has main effects on Tyr of BSA and both Tyr and Trp of HSA. The experimental results have provided the certain theory basis of the mechanism of interaction between alliin and biological small molecules..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1826 (2017)
Effects of Temperature on DNA Condensation Detected with
GONG Hong-ling, LIU Yan-hui, TANG Yan-lin, and HU Lin
Recent fluorescent single molecule experiment indicated that temperature can facilitate DNA condensation. In the spermine (spermidine)-DNA condensation system, DNA condensation conformation became more compact and orderly with increasing temperature . In order to detect the temperature effects in DNA condensation systeRecent fluorescent single molecule experiment indicated that temperature can facilitate DNA condensation. In the spermine (spermidine)-DNA condensation system, DNA condensation conformation became more compact and orderly with increasing temperature . In order to detect the temperature effects in DNA condensation system further, a temperature-changed ultraviolet spectrum method is developed. By applying the method to the condensation system mentioned by recent fluorescent single molecule experiment and the DNA in DI water, a conclusion is derived from the absorption value at 260 nm of a condensation system will be reduced, when the corresponding system is further condensed and become compact and orderly. Based on this conclusion, effects of temperature on DNA- cobalt amine compounds used in DNA condensation experiments are detected by using temperature-changed ultraviolet Spectrum method. The results indicate that Hexaammine cobalt(Ⅲ) chloride is similar to spermine and spermidine, the UV absorption value at 260 nm of DNA reduces sharply with the temperature increasing, indicating that the DNA conformation tends to be more compact and orderly. However, for the condensation system wherein the DNA is condensed by trans (ethylenediamine) cobalt(Ⅲ) chloride, trans-dichlorobis (ethylenediamine) cobalt(Ⅲ) chloride and pentaamminechloro cobalt(Ⅲ) chloride, respectively, the UV absorption value at 260 nm of the corresponding condensation. System does not change with temperature monotonously, taking an increased-reduced-increased manner..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1831 (2017)
Synthesis, Crystal Structure and Ion Recognition of ［ONSO］ Salen Compounds
LI Miao, DUAN Xiao-meng, JIA Tao, DUAN Zhong-yu, and LIU Bin-yuan
Some heavy metal ions can be toxic to the environment and organisms even with low concentrations, thus, it is of great significance to study trace metal ion recognition. Because of its good selectivity, high sensitivity, low cost and real-time response, the fluorescence sensor has been widely applied. A novel class salSome heavy metal ions can be toxic to the environment and organisms even with low concentrations, thus, it is of great significance to study trace metal ion recognition. Because of its good selectivity, high sensitivity, low cost and real-time response, the fluorescence sensor has been widely applied. A novel class salen ligand L1 was synthesized with 2,4-di-tert-butyl-phenol, 3,5-di-tert-butyl-salicylaldehyde and 2-aminothiophenol. Its structure was characterized with1H NMR, 13C NMR, IR, elemental analysis and X-ray single crystal techniques. The single crystal structure of ligand L1 was obtained with free evaporation method, and the experimental results show that L1 is a hole plane［ONSO］ four coordination environment of three inclined and P-1 space group. The recognition properties of the target compound L1 with metal ions (Li+, Na+, K+, Cd2+, Cs+, Co2+, Cu2+, Hg2+, Mn2+, Ni2+, Zn2+, Ag+) had been investigated with fluorescence spectrophotometry. The binding of L1 to Zn2+ are in 1∶1 stoichometry. The results showed that L1 exhibited the selective recognition to Zn2+, and the detection limit was down to 501×10-5 mol·L-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1838 (2017)
An Insight into the Nanostructure of Cell on Histology Specimen via Microscopic Spectrum
WANG Pin, WU Ye, LI Yong-ming, LI Fan, and YAN Fang
Structure properties of cell, especially at nanoscale, have shown great potential in early cancer diagnosis and screening. The research has shown that spatial-domain low-coherence quantitative phase microscopy (SL-QPM) can obtain the optical markers which related to the subtle change of nanoscale structure. There is a Structure properties of cell, especially at nanoscale, have shown great potential in early cancer diagnosis and screening. The research has shown that spatial-domain low-coherence quantitative phase microscopy (SL-QPM) can obtain the optical markers which related to the subtle change of nanoscale structure. There is a complex nonlinear relationship between the optical markers and the nanoscale structure parameters. In this paper, a theoretical model of backscattering spectrum of SL-QPM is built with one dimensional Gaussian random field model with one dimensional multilayer dielectric slab model. The result shows that the simulation spectrum matches well with the experimental result. Then the numerical analysis is presented on a series model of histology slides with various known structure properties. We validated that the optical makers of SL-SQM (the average phase, the standard deviation of phase, the average amplitude, the standard deviation of amplitude, the fluctuation ratio) can detect the subtle change of the cell structure( the average refractive index, the variation of refractive index, the spatial correlation length). It provide theoretical basis for the early cancer detection based on SL-QPM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1843 (2017)
Effects of Long-Term Green Manure Application on the Concentrations of Mineral Elements in Grain of Dryland Wheat in Northwest of China
BAI Jin-shun, CAO Wei-dong, BAO Xing-guo, RUI Yu-kui, ZENG Nao-hua, GAO Song-juan, and Shimizu Katsuyoshi
Green manure is an important managing practice to secure high crop yield, improve soil fertility and nutrient efficiency. However, it was still not clear about the influence of long-term green manure incorporation on mineral elements concentrations in grain of dryland wheat. In this study, inductively coupled plasma maGreen manure is an important managing practice to secure high crop yield, improve soil fertility and nutrient efficiency. However, it was still not clear about the influence of long-term green manure incorporation on mineral elements concentrations in grain of dryland wheat. In this study, inductively coupled plasma mass spectrometry (ICP-MS) technique was applied to evaluate the impact of long-term green manure application on mineral elements of wheat grains which were collected from three experimental treatments including control of non fertilization, chemical fertilization and green manure at wheat harvest in a 25-year wheat experiment conducted in Wuwei, Gansu province. The results showed that most of the mineral elements content of wheat grain under green manure treatment showed an increase trend compared with non fertilization treatment. The elements of Si, Fe, and Ru showed the significant increase under green manure treatment. Besides, it was found the content of all heavy metals in wheat grains showed no significant difference compared with the non fertilization treatment. However, Ni element increased compared with the chemical fertilizer treatment. In conclusion, long-term green manure incorporation can improve some mineral nutrient elements in grain of dryland wheat, which may contribute to the grain nutritional quality while maintaining high wheat yield. However, the effects of green manure application on the behaviors of heavy metals in soil-plant system required further research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1847 (2017)
Review of Hyperspectral Imaging Technology in Analyzing Painted Artifacts
HOU Miao-le, PAN Ning, MA Qing-lin, HE Hai-ping, L Shu-qiang, and HU Yun-gang
The painted artifacts is an important part of the cultural heritage. At present, chemical, spectral analysis and digital imaging technologies have been applied in the research of painted artifacts. It is true that hyperspectral imaging technology set spectral analysis and imaging technology have the advantages of beingThe painted artifacts is an important part of the cultural heritage. At present, chemical, spectral analysis and digital imaging technologies have been applied in the research of painted artifacts. It is true that hyperspectral imaging technology set spectral analysis and imaging technology have the advantages of being nondestructive, fast imaging and “image-spectrum merged”. Because of these technical characteristics, hyperspectral imaging technology functions under the condition of non-contact and without sample for the non-destructive researching of painted artifacts. Meanwhile, the unique advantage of hyperspectral imaging technology compared to other analysis technique of painted artifacts is that the overall morphology characteristics and the in-depth spectral e characteristics of painted artifacts both can be obtained from hyperspectral images. There are three steps in the research of painted artifacts with hyperspectral imaging technology including data acquisition, data analysis and the application of data. Among them, data analysis and application are the main content of the study. Through summarizing the related researches of hyperspectral imaging technology in painted artifacts, the data processing methods are analyzed from four aspects: hyperspectral dimension reduction, spectral feature parameters, hyperspectral unmixing and classification method. The main functions, common methods and case studies of four data processing methods are described. The application of related researches can be summed up in four directions: vision enhancement, revealing hidden information, production monitoring, and pigment identification, which is described from the content and solved problems. In the end, the challenges of existing related research are summarized, and and carries on the prospects..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1852 (2017)
Application of Hyper-Spectra for Detecting Peroxidase Content in Cucumber Leaves with Early Disease Stress
CHENG Fan, ZHAO Yan-ru, YU Ke-qiang, LOU Bing-gan, and HE Yong
Visible/near-infrared hyper-spectra technique was applied to detect peroxidase (POD) content in cucumber leaves with early bacterial angular leaf-spot disease (BALD) stress. A total of 120 samples with three BALD infection stages were used to acquire with hyper-spectra with in the range of 380~1 030 nm (512 wavelengthsVisible/near-infrared hyper-spectra technique was applied to detect peroxidase (POD) content in cucumber leaves with early bacterial angular leaf-spot disease (BALD) stress. A total of 120 samples with three BALD infection stages were used to acquire with hyper-spectra with in the range of 380~1 030 nm (512 wavelengths) and corresponding POD content in the leaves were measured with spectrophotometer method. Analysis of variance (ANOVA) were applied to process statistical analysis of the measured POD content and results showed that there was significant difference (p=005) about the POD content in the cucumber leaves with the three stages of BALD stress. SPXY method was employed to divide the samples into a calibration set (n=80) and a prediction set (n=40). Random Frog (RF) and regression coefficient (RC) were used to select the characteristic wavelengths to reduce data dimensions. Partial least square regression (PLSR) was applied to develop the quantitative relationship between spectra and POD content. RF-PLSR was the optimal model to predict POD content with correlation coefficient (r) of 0816 with root mean squared error of prediction (RMSEP) of 11235. The result showed that hyper-spectra technique combined with chemometrics method was promising for detecting POD content in the cucumber leaves with different BALD developments. This study provided a theoretical reference for early detecting disease infection in non-destructive way..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1861 (2017)
Identification and Classification of Different Producing Years of Dried Tangerine Using Hyperspectral Technique with Chemometrics Models
BAO Yi-dan, L Yang-yang, ZHU Hong-yan, ZHAO Yan-ru, and HE Yong
The shoddy phenomena often occur in the market, and the producing year is an important index to measure the quality of dried tangerine. Thus, this research applied hyperspectral technique in the spectral windows of 380～1 023 and 874～1 734 nm combined with chemometric methods to identify different producing years of driThe shoddy phenomena often occur in the market, and the producing year is an important index to measure the quality of dried tangerine. Thus, this research applied hyperspectral technique in the spectral windows of 380～1 023 and 874～1 734 nm combined with chemometric methods to identify different producing years of dried tangerine. Due to the actual detection of dried tangerine, spectra of front and back of dried tangerine were acquired. Hyperspectral imagesat both sides of a total of 180 samples of four years were collected within 380～1 023 and 874～1 734 nm (720 pictures). Then principal component analysis (PCA) was carried out on the spectral data, which had a qualitativeanalysis about the dried tangerine. Regression coefficient (RC) was chosen to select the sensitive variables. Partial least squares-discrimiant analysis (PLS-DA) were used to compare the performances of full-spectra and sensitive variables. Finally, the linear PLS-DA model and nonlinear ELM model were established based on the sensitive bands. The results demonstrated that most of the predictive effects in 874～1 734 nm were higher than that of 380～1 023 nm. ELM models were outperformed PLS-DA among all the developed models, the highest accuracy was achieved 100% in the model set, and 9833% in the prediction set. No matter what kind of placement, the prediction accuracy rate was higher than 85%. Hence, hyperspectral technique with chemometrics models can realize nondestructive identification of various producing years of dried tangerine, which provides a theoretical reference and basis for developing instruments of recognition the dried tangerine in further research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1866 (2017)
The Hyperspectral Diagnosis Model for Acid Stress of Cinnamomum camphora
LI Xin-hui, ZHANG Xiu-ying, MA Yuan-dan, JIN Jia-xin, CHENG Min, ZHANG Xiao-min, and JIANG Hong
The hyperspectral technique plays an important role in detecting the response of plant under the acid stress. Taking Cinnamomum camphora as the subject, the hyperspectral information at leaf scale under 419 days of acid disposals was measured. Differing from other kinds of environmental stresses, the responses of plantThe hyperspectral technique plays an important role in detecting the response of plant under the acid stress. Taking Cinnamomum camphora as the subject, the hyperspectral information at leaf scale under 419 days of acid disposals was measured. Differing from other kinds of environmental stresses, the responses of plants under acid stress are more complicated due to the fertilizer effect of sulfur and nitrogen. Based on the hyperspectral monitoring on the leaf of Cinnamomum camphora under four grades of acid rains (pH 56, pH 45, pH 30, pH 20), the aim of this study is to find the turning point from promoting to inhibiting growth by acid rain. Based on the 16 terms of hyperspectral data, the pretreatments were firstly conducted and the abnormal values were removed; and then the typical spectrals were selected based on the temporal variations of leaf response (the differences of the spectral values under pH 56 minus those under pH 45, pH 30, pH 20, respectively) under acid stresses; finally the diagnostic models were constructed using the typical spectral. The results showed that the typical bands to reflect the response of Cinnamomum camphora under acid stresses were mainly within 470~520 and 565~700 nm, based on which the difference of blue edge index and the difference of yellow edge index were built. The acid rain with pH 45 and pH 30 first promoted and then inhibited the growth of Cinnamomum camphora, with the turning point at 100 days and 50 days of spraying acid rain, respectively. The acid rain with pH 20 inhibited the growth of Cinnamomum camphora at the beginning of acid treatments, and this inhibition had been strengthened with time increasing. This study showed that the long term of hyperspectral monitoring could indicate the temporal variations of the responses of Cinnamomum camphora under acid treatments. These results could provide scientific information for monitoring the plant responses under acid rain at a regional scale, which also provide scientific suggestions for the government to enact environmental protection plans..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1872 (2017)
Research of Macroscopic and Microcosmic Fabric Characteristics in Geological Samples Based on Variety of Spectroscopy Technology: A Case Study in Jinshan Ag-Au Deposit of Southern Qinzhou-Hangzhou Metallogenic Belt, China
GAO Le, SU Zhi-hua, LI Hong-zhong, YU Peng-peng, NIU Jia, LU Yu-tong, and XU Shu-teng
The complexity of geological processes created the macroscopic and microcosmic characteristics of geological samples with inhomogenous features. These features can be revealed effective through spectroscopy analysis technology. This study took the ore and surrounding rock samples from Jinshan Ag-Au deposit of southern The complexity of geological processes created the macroscopic and microcosmic characteristics of geological samples with inhomogenous features. These features can be revealed effective through spectroscopy analysis technology. This study took the ore and surrounding rock samples from Jinshan Ag-Au deposit of southern Qinzhou-Hangzhou metallogenic belt while carrying out macroscopic geochemical characteristic and microcosmic characteristics analysis based on the X-ray fluorescence spectroscopy, plasma mass spectrometry and Raman spectrum. The results showed that the main elements of ore and surrounding rock had great differences while the distribution patterns of trace element and rare earth element were similar. It reflected that the trace elements and rare earth elements showed high geochemical stability in the process of mineralization. Raman spectral characteristics of quarts showed that the peak at 507 cm-1 did exist in ore samples, but disappeared in surrounding rock samples. It indicated that the ore and surrounding rock went through different temperature and pressure in the ore-forming process, and the peak could be used as the signs of whether exists mineralization. Comparison with the Raman shift next to 463 cm-1 for quartz between ore and surrounding rocks, the FWHM and integral strength of fitting peak denote that the quartz in ore samples have better crystal degree than that of quartz in country rocks . These quartz microstructure changes should be subjected to the late hydrothermal activity. The quartz in the surrounding rock is influenced by the late hydrothermal, part of the ore-forming fluid may be from surrounding rock, and the ore-forming fluid has multiple phase, the crystallization degree of mineral was in different stages, causing different FWHM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1879 (2017)
Detection of Heavy Metal Elements in the Mixture Solution with Laser Induced Breakdown Spectroscopy
SONG Chao, ZHANG Ya-wei, and GAO Xun
In this paper, the concentrations of Cu, Mg, Zn and Cd elements in the mixture solution consing of CuSO4, Mg(NO3)2, Zn(NO3)2 and Cd(NO3)2 were measured with Laser Induced Breakdown Spectroscopy with aqueous jets which were generated within 1 064 nm wavelength of Nd: YAG laser with pulse width of 10ns and repetitive ratIn this paper, the concentrations of Cu, Mg, Zn and Cd elements in the mixture solution consing of CuSO4, Mg(NO3)2, Zn(NO3)2 and Cd(NO3)2 were measured with Laser Induced Breakdown Spectroscopy with aqueous jets which were generated within 1 064 nm wavelength of Nd: YAG laser with pulse width of 10ns and repetitive rate of 10 Hz. The mixture solutions of seven different concentrations consist of Cu, Mg, Zn and Cd were compound by adding the four solutes to the distilled water. The LIBS experiment date have been treated with the statistical exploratory data analysis method to abtain calibration curves of Cu, Mg, Zn and Cd elements, whose linear fitting coefficient R2 were all above 099, the LOD of Cu, Mg, Zn and Cd elements were determined as 562, 471, 1367 and 443 ppm, respectively. The LOD of Cu element was 398 ppm for pure CuSO4 solution with better experimental results than that of mixed solution, Finally, the LIBS detected differences were analyzed. The research results show that LIBS has a promising application in detecting heavy metal elements in the environmental wastewater pollution．.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1885 (2017)
Effects of Laser Wavelength on Properties of Coal LIBS Spectrum
QIAN Yan, ZHONG Sha, HE Yong, Ronald Whiddon, WANG Zhi-hua, and CEN Ke-fa
In face of the complicated and changeable coal in Chinese power stations, the on-line measurement of coal elemental composition is extremely significant in terms of enhancing the safety and efficiency of boilers as well as lowering the waste emission during operation. In this work, laser induced breakdown spectroscopy In face of the complicated and changeable coal in Chinese power stations, the on-line measurement of coal elemental composition is extremely significant in terms of enhancing the safety and efficiency of boilers as well as lowering the waste emission during operation. In this work, laser induced breakdown spectroscopy (LIBS) was applied to coal quality measurement. Laser wavelength was changed as 355, 532 and 1 064 nm to investigate the influence on coal LIBS features, including plasma time evolution and the spectral lines intensity-time characteristics of different elements. Energy threshold for shielding effect was also tested to verify how it varies with laser wavelengths. Additionally, coal LIBS spectrum was analyzed under different laser wavelengths. It has been proven by experiments that higher intensity of coal LIBS spectrum and energy threshold can be easily achieved when using laser of 532 nm, making it a fantastic energy source for coal LIBS tests. Results of these experiments serve to guide the industrial application of LIBS technology in the field of coal quality measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1890 (2017)
Inhomogeneity of Ovalbumin Glycosylation Products in Microwave Field with Spectral Analysis
ZHONG Bi-zhen, TU Zong-cai, and WANG Hui
In this experiment, the mixed system of ovalbumin and glucose were constructed as the research object of glycosylation reaction model. Then the infrared, fluorescence and UV were used to analyze the product of different position in microwave field. Ovalbumin and glucose were mixed into 5% solution with the proportion oIn this experiment, the mixed system of ovalbumin and glucose were constructed as the research object of glycosylation reaction model. Then the infrared, fluorescence and UV were used to analyze the product of different position in microwave field. Ovalbumin and glucose were mixed into 5% solution with the proportion of 1∶1. Then it formed into a plane model with a thickness of 5mm after freeze-drying for 48h. The reaction was taken in the microwave oven, the reacted samples were divided into five regions, including No.1 in the center of the microwave oven, No. 2 near the magnetron, No. 3, No.4 and No.5, away from the magnetron. The results showed that the mixture of protein and sugar reacted unevenly under the condition of 560 W for 9 minutes in microwave. SDS-PAGE electrophoresis diagram and the content of free amino showed that with the action of microwave glycosylation does exist larger nonuniformity; by analysing fluorescence and three-dimensional fluorescence spectrum, it was found that glycosylation reaction created new fluorescent substances, including 3, 4, and 5 location created new larger fluorescence peaks which were from the advanced products of the glycosylation; infrared spectrum analysis showed that new N—H key was generated; UV analysis showed that in plane of glycosylation reaction model, location 3 was the highest level of response..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1896 (2017)
Study on Adsorption and Desorption Characteristics of Pb(Ⅱ) and Cr(Ⅵ) onto the Surface Sediments of Hequ Section of the Yellow River with ICP-MS
TIAN Meng-jing, JIA Jia, QIAO Yu, WU Ting-yan, LI He-xiang, and LIU Ying
Surface sediments, as the source and sink of heavy metals in polluted water, are easy to enrich and release heavy metals in water environment. In fact, the water of Hequ section of the Yellow River was polluted by Pb and Cr. In this paper, the adsorption and desorption characteristics of Pb(Ⅱ) and Cr(Ⅵ) onto the surfacSurface sediments, as the source and sink of heavy metals in polluted water, are easy to enrich and release heavy metals in water environment. In fact, the water of Hequ section of the Yellow River was polluted by Pb and Cr. In this paper, the adsorption and desorption characteristics of Pb(Ⅱ) and Cr(Ⅵ) onto the surface sediments of Hequ section of the Yellow River were investigated by using inductively coupled plasma mass spectrometry (ICP-MS) under the optimized experimental conditions. The results showed that the sediments had strong adsorption effects to Pb(Ⅱ) and Cr(Ⅵ) with endothermic and spontaneous process (ΔG<0, ΔH>0) with the adsorption rates reaching more than 98% in the initial 5 min. Kinetic experiments showed that the adsorptions of Pb(Ⅱ) and Cr(Ⅵ) were in accordance with the pseudo-second-order kinetics. The isothermal adsorption equations revealed that the adsorption of Pb(Ⅱ) was consistent with the Langmuir model, while the adsorption of Cr(Ⅵ) followed the Freundlich model. The desorption processes kept to the Elovich equation, which was influenced chiefly by pH. The competitive adsorption of Pb(Ⅱ) and Cr(Ⅵ) showed that the adsorption rate of Pb(Ⅱ) was greater than that of Cr(Ⅵ), while both of them were lower than the single ion adsorption rate. Scanning electron microscopy (SEM), pore size and specific surface area analysis showed that the sediments of Hequ section of the Yellow River had an irregular surface structure and a relatively high specific surface area. This paper displayed the adsorption-desorption behaviors of Pb(Ⅱ) and Cr(Ⅵ) onto the sediments of Hequ section of the Yellow River, which has guiding significance for sediment pollution assessment, pollution remediation and mastering the mechanism of heavy metals onto the sediments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1902 (2017)
Fast Identification of Matcha and Green Tea Powder with Laser-Induced Breakdown Spectroscopy
YU Xiao-lan, PENG Ji-yu, LIU Fei, and HE Yong
The feasibility of using laser-induced breakdown spectroscopy (LIBS) combined with chemometrics methods for fast identification of matcha and green tea powder was investigated in this paper. The main differences between matcha and green tea powder are varieties of tea plants, cultivation management, growth time and proThe feasibility of using laser-induced breakdown spectroscopy (LIBS) combined with chemometrics methods for fast identification of matcha and green tea powder was investigated in this paper. The main differences between matcha and green tea powder are varieties of tea plants, cultivation management, growth time and processing technology. LIBS spectra between 230 to 880 nm of matcha produced by different manufacturers and green tea powder made with different fixation methods were selected and min-max normalization was the measure for preprocessing. Characteristic wavelengths were selected according to the X-variables loadings on the basis of principal component analysis (PCA), and then linear discriminant analysis (LDA) models were built based on characteristic wavelengths. The results showed that the LDA model based on characteristic wavelengths could identify matcha and green tea powder rapidly. Four characteristic wavelengths belong to C(Ⅰ) 24794 nm, Mg(Ⅱ) 27960 nm, Ca(Ⅱ) 39345 nm and Fe(Ⅱ) 76668 nm. The accuracy of the calibration and the prediction set all reached 100%. Laser-induced breakdown spectroscopy could accurately identify matcha produced by different manufacturers and green tea powder made with different fixation methods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1908 (2017)
Study on Simultaneous and Rapid Analysis Method of X-Ray Fluorescence Spectrum for Determination of Chromium, Cadmium and Lead in Water
GAN Ting-ting, ZHAO Nan-jing, YIN Gao-fang, XIAO Xue, ZHANG Yu-jun, ZHANG Wei, LIU Jian-guo, and LIU Wen-qing
Coprecipitation method was adopted for simultaneous enrichment Cr, Cd and Pb in water by using sodium hydroxide and sodium sulfide as precipitant. The precipitation homogeneous suspension of Cr(OH)3, Cd(OH)2 and PbS was filtered to prepare uniform Cr, Cd and Pb thin film samples. The energy dispersive XRF spectra of thCoprecipitation method was adopted for simultaneous enrichment Cr, Cd and Pb in water by using sodium hydroxide and sodium sulfide as precipitant. The precipitation homogeneous suspension of Cr(OH)3, Cd(OH)2 and PbS was filtered to prepare uniform Cr, Cd and Pb thin film samples. The energy dispersive XRF spectra of thin film samples were measured in order to realize simultaneous and rapid analysis and determination of Cr, Cd and Pb in water. The influence of reaction time and molar ratio of reactants in the process of enrichment to the XRF spectrum intensity of thin film samples was studied. The precipitation reaction time for 5 min, the best mole ratios of OH- with Cr3+ for 50, OH- with Cd2+ for 50, and S2- with Pb2+ for 20 were the optimum reaction conditions. The homogeneity of thin film samples with different concentrations after enrichment was tested. All the relative standard deviations of fluorescence intensity at six different positions at enrichment area were less than 48%, which indicates that all the thin film samples are in good uniformity. The theoretical concentration of thin film samples with different concentrations was compared with measured concentration with ICP-MS method, which confirms that the enrichment rate of this enrichment method for Cr, Cd and Pb in water can reach more than 90%. According to the fluorescence intensity of the thin film samples and the concentration measurements with ICP-MS, the quantitative analysis method of X-ray fluorescence spectrum for Cr, Cd and Pb in water based on the above enrichment was established. The linear correlation coefficients of Cr, Cd and Pb calibration curve were 0997 3, 0995 0 and 0999 8, respectively. When the volume of actually collecting water sample for 50ml, the detection limits of Cr, Cd and Pb were 74, 296 and 85 μg·L-1, respectively. All the detection limits are lower than the maximum allowable emission concentration of Cr, Cd and Pb in (Integrated wastewater discharge standard GB 8978—1996). So this method can realize the simultaneous and rapid analysis and determination of Cr, Cd and Pb in the discharged wastewater of industrial production and life. This study provides a basis for simultaneous and rapid on-line monitoring of a variety of heavy metals in water for X-ray fluorescence spectrometry..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1912 (2017)
Quantitative Study of the Microcrystal Structure on Coal Based on Needle Coke with Curve-Fitted of XRD and Raman Spectrum
ZHU Ya-ming, ZHAO Xue-fei, GAO Li-juan, CHENG Jun-xia, L Jun, and LAI Shi-quan
Three kinds of needle coke (numbered as Coke-N, Coke-H and Coke-P) from different sources were studied with X-ray diffraction (XRD), Raman spectrum and curve-fitting analysis. The graphitization degree, crystal structure types and crystal size (La and Lc) of these three needle cokes were calculated with XRD. According Three kinds of needle coke (numbered as Coke-N, Coke-H and Coke-P) from different sources were studied with X-ray diffraction (XRD), Raman spectrum and curve-fitting analysis. The graphitization degree, crystal structure types and crystal size (La and Lc) of these three needle cokes were calculated with XRD. According to the curve-fitted analysis of XRD, the content of ordered crystallite structure (Ig) on the three needle coke samples was obtained. The graphitization degree of Coke-N and Coke-P were similar, which were obviously greater than that of Coke-H; the relationship of La between these needle cokes are: Coke-N＞Coke-P＞Coke-H. Raman spectrum coupled with curve-fitted method was used for quantitative analysis of samples. With Raman spectrum and math method, the cokes at zone of 1 000~2 000 cm-1 had been analyzed with curve-fitted method. This first-order spectrum had been curve-fitted to five peaks (G, D1, D2, D3, D4). The area of each fitted curve was used to calculate the distribution of carbon crystalline. The parameters of IG/IAll, ID1/IG, ID2/IG, ID3/IG and ID4/IG had shown that, the crystallite structure of Coke-N and Coke-P were more order than Coke-H. The ratio of ideal microcrystalline graphite carbon in Coke-N was 033, but the parameters of Coke-H and Coke-P were 0086 and 0311 respectively. What’s more, the ratio of amorphous carbon in Coke-H was obviously higher than other that of two samples. The results were corresponding to that of XRD analysis. Therefore, XRD and Raman spectrum analysis was an important method to judge the essence of coal-based needle cokes with different macro quality on the microcosmic level..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1919 (2017)
Rapid Detection System for HSA Based on RRS
LI Yuan, LI Kai, and ZHAO Dong-e
In the clinic, for the diagnosis of a variety of major diseases, it has great significance in terms of quick detection of concentration of human serum albumin (HSA). However, there are bulky, long test cycle, complex operations and other shortcomings for common medical detection equipment. It will have a very broad appIn the clinic, for the diagnosis of a variety of major diseases, it has great significance in terms of quick detection of concentration of human serum albumin (HSA). However, there are bulky, long test cycle, complex operations and other shortcomings for common medical detection equipment. It will have a very broad application prospects as for the design of a fast, high-precision portable detection system for HSA concentration. HSA concentration detection system was designed based on Resonance Rayleigh Scattering(RRS) spectroscopy. The mixed solution was generated with HSA and Tetraamino-phthalocyanine copper (CuTAPc) reaction, and it had a RRS enhancement effect at 4750 nm, whereby the function of RRS intensity and HSA concentration was constructed. In the experiment, ultraviolet semiconductor lasers and 4750 nm narrowband filter was used, the scattered light signal was collected with high gain photo-detector. Different concentrations of HSA were respectively detected with different concentrations of CuTAPc. Experimental results show that response voltage will increase significantly with the increasing of concentrations of HSA, but it is not sensitive to concentration changes for CuTAPc; It basically meet the linear change by the response voltage from scattered light and the concentration of HSA in the range from 01 to 10 μg·mL-1, and it meets the design requirements of rapid detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1925 (2017)
Extinction Coefficient Measurement of Atmospheric Particles with Differential Optical Absorption Spectroscopy
LI Su-wen, MO Fu-sheng, SHI Rui-rui, and WEN Min-hong
The atmospheric complex pollution becomes more and more serious, which results in enhanced atmospheric oxidation and accelerated interconversion of pollution trace gases and particles. Differential optical absorption spectroscopy (DOAS) is developed to monitor the characteristics of atmospheric particles in a large scaThe atmospheric complex pollution becomes more and more serious, which results in enhanced atmospheric oxidation and accelerated interconversion of pollution trace gases and particles. Differential optical absorption spectroscopy (DOAS) is developed to monitor the characteristics of atmospheric particles in a large scale. The method of differential optical absorption spectroscopy is applied to real-time, online and simultaneous determination concentrations of atmospheric trace gases and extinction coefficients of particles. Method of extinction measurement of atmospheric particles is discussed basing on double optical paths DOAS system. The single optical path DOAS system is discussed for measuring the particle extinction coefficients in this paper. The DOAS system need to be calibrated to measure particle extinction. Firstly, the reference spectrum is measured under the clean atmospheric condition with visibility data. Then the absorption intensity of 550 nm wavelength is recorded to obtain correction coefficient of the the DOAS system. The total absolute optical intensity of atmosphere can be retrieved after calibrating the system parameter. The particle extinction coefficients are obtained by removing the contribution of trace gases and Rayleigh scattering from the total optical intensity. The particle extinctions are obtained from 350 to 700 nm and trace gases concentrations of NO2 are simultaneously retrieved basing on differential principle in the field campaign. The particle extinction coefficients decrease with wavelengths, which is in accordance with Angstrom formula. The research can provide raw data support to study atmospheric heterogeneous gas/particle chemical reaction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1930 (2017)
Multi-Spectral Ship Target Recognition Based on Feature Level Fusion
LIU Feng, SHEN Tong-sheng, GUO Shao-jun, and ZHANG Jian
Aiming at solving the problem of inadequate ability of recognizing single band warship targets on the sea in complicated situations, image fusion technology for three band feature levels of visible light, short wave infrared and medium wave infrared has been studied. Problems of time-consuming and fusion strategy existAiming at solving the problem of inadequate ability of recognizing single band warship targets on the sea in complicated situations, image fusion technology for three band feature levels of visible light, short wave infrared and medium wave infrared has been studied. Problems of time-consuming and fusion strategy existed in image fusion have been solved as top priorities. A new multi-band fusion method based on regional covariance matrix has been proposed in this paper. The advantage is that it can fuse several related features naturally through low dimensional vector. This paper has designed 11-dimensional and 5-dimensional feature vectors for visible light image and infrared image respectively, which not only ensures the differences among different targets but also decreases the calculation. Saliency detection has been adopted firstly in this paper to position the target area in the image quickly; and then, distance calculation formula of covariance matrix has been defined for the feature vectors of different band image designs and matching has been made in the following; integral image has been attained through one traversal operation for the image; purpose of quick calculation has been realized in the calculation for covariance; finally, K-nearest neighbor (KNN) algorithm has been adopted to make classification and recognition for various warship targets. Over 3 400 images of three-band warship target have been used as testing data. The experiment mainly includes two parts: first, comparing the recognition rate of single-band and three-band fusion recognition and to verify that the fusion method proposed in this paper has more extensive application range. Second, comparing several traditional pixel level methods in the calculation efficiency to verify the advantages of feature fusion adopted in this paper in calculation time. Experimental results have shown that the recognition rate of this method can reach 95.1% and time for single frame calculation is about 0.5 s, which has made distinctive improvement in both real time and detection rate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1934 (2017)
Multi-Spectral Ship Target Recognition Based on Feature Level Fusion
LIU Feng, SHEN Tong-sheng, GUO Shao-jun, and ZHANG Jian
Aiming at solving the problem of inadequate ability of recognizing single band warship targets on the sea in complicated situations, image fusion technology for three band feature levels of visible light, short wave infrared and medium wave infrared has been studied. Problems of time-consuming and fusion strategy existAiming at solving the problem of inadequate ability of recognizing single band warship targets on the sea in complicated situations, image fusion technology for three band feature levels of visible light, short wave infrared and medium wave infrared has been studied. Problems of time-consuming and fusion strategy existed in image fusion have been solved as top priorities. A new multi-band fusion method based on regional covariance matrix has been proposed in this paper. The advantage is that it can fuse several related features naturally through low dimensional vector. This paper has designed 11-dimensional and 5-dimensional feature vectors for visible light image and infrared image respectively, which not only ensures the differences among different targets but also decreases the calculation. Saliency detection has been adopted firstly in this paper to position the target area in the image quickly; and then, distance calculation formula of covariance matrix has been defined for the feature vectors of different band image designs and matching has been made in the following; integral image has been attained through one traversal operation for the image; purpose of quick calculation has been realized in the calculation for covariance; finally, K-nearest neighbor (KNN) algorithm has been adopted to make classification and recognition for various warship targets. Over 3 400 images of three-band warship target have been used as testing data. The experiment mainly includes two parts: first, comparing the recognition rate of single-band and three-band fusion recognition and to verify that the fusion method proposed in this paper has more extensive application range. Second, comparing several traditional pixel level methods in the calculation efficiency to verify the advantages of feature fusion adopted in this paper in calculation time. Experimental results have shown that the recognition rate of this method can reach 951% and time for single frame calculation is about 05 s, which has made distinctive improvement in both real time and detection rate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1934 (2017)
Phantom Experimental Validation of Near Floating Reference Measuring Method in Non-Invasive Blood Glucose Sensing
XIA Dan-dan, HAN Guang, YU Xu-yao, LI Chen-xi, LIU Rong, JIANG Jing-ying, and XU Ke-xin
In near-infrared non-invasive blood glucose measurement, the signal variation caused by glucose is very weak, vulnerable to human involvement, measuring instruments and environmental changes, limiting the accuracy of non-invasive blood glucose sensing. To address this issue, the group applies the theory of floating refIn near-infrared non-invasive blood glucose measurement, the signal variation caused by glucose is very weak, vulnerable to human involvement, measuring instruments and environmental changes, limiting the accuracy of non-invasive blood glucose sensing. To address this issue, the group applies the theory of floating reference position to eliminate background interference.However, due to the individual differences and the complexity of human environment, the floating reference positions will vary from person to person.Based on the Monte Carlo simulation of three layer skin model of human palm, the floating reference positions of 1 000~1 700 nm near infrared band were found in the vicinity of 2 mm of the radial distance from the light source.So in order to improve the applicability of the floating reference methods in different persons, this paper presents a near floating reference measuring(N-FRM) method. The radial distance 2 mm was chosen as the reference position for background interference’s correction, then the effect by phantom experiments is validated. Furthermore select the phantom Intralipid solution with 2% and 3% concentration for experiments, whose floating reference positions are close to the skin model of human palm. The results showed that the N-FRM method could reduce the influence of light source drift, improve the repeatability and stability of data. Based on multiple diffuse reflection signal acquisition of 2% and 3% intralipid solutions with different glucose content and the glucose concentration prediction models, and it was found that the regression models' root mean square errors of prediction were reduced by 3851%~7998% and 2972%~5222%. The comparison showed that this method could effectively eliminate the common background changes at two measured positions,improve the prediction accuracy of the calibration models. The results of phantom experiments provide a strong support for the application of N-FRM’s in vivo measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1941 (2017)
Movable GaN Membrane Micro-Grating on Patterned SOI Substrate Deposited with Molecular Beam Epitaxy
L Fan-min, LI Pei, WANG Yong-jin, HU Fang-ren, and ZHU Wen-zhen
As the third generation of semiconductor material, GaN has many advantages, such as wide bandgap, direct band gap, corrosion resistance and so on. Also, GaN is a very promising material for MOEMS. Because the etching of GaN material is not mature, epitaxial growth on patterned substrate is more helpful for GaN/SOI deviAs the third generation of semiconductor material, GaN has many advantages, such as wide bandgap, direct band gap, corrosion resistance and so on. Also, GaN is a very promising material for MOEMS. Because the etching of GaN material is not mature, epitaxial growth on patterned substrate is more helpful for GaN/SOI device. A movable GaN grating on patterned SOI substrate was designed and fabricated with Si micromaching and molecular beam epitaxy process of GaN. The grating actuated by a SOI electrostatic comb-drive micro-actuator could move in two dimensional directions and it could be used as filter in Terahertz wavelength. The period and width of the grating is 16 and 6 μm, respectively. The resonant wavelength is 25901 μm. An horizontal displacement of ±726 μm is obtained at 220 V of horizontal voltage with simulation. When the vertical voltage is 200 V, the displacement is 25 μm. The photoluminescence (PL) measurements of the deposited InGaN/GaN multiple quantum well on patterned SOI substrate are carried out with laser Raman spectrometer. The experimental results show that good optical property of the InGaN/GaN multiple quantum well. A wide emission wavelength from 350 to 500 nm is demonstrated. With the increase of temperature from 10 K to room temperature, the photoluminescence peak position appears a tendency of “S” shape because of the localized effect and band shrink in the InGaN/GaN quantum well..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1946 (2017)
Difference Analysis of LAMOST Stellar Spectrum and Kurucz Model Based on Grid Clustering
CHEN Shu-xin, SUN Wei-min, and KONG Xiao
With the vigorous development of the big data astronomical calculation science, our country has obtained independent intellectual property rights of the international astronomical community.LAMOST telescope has taken the lead in the world in terms of development and implementation of combining the observation with massWith the vigorous development of the big data astronomical calculation science, our country has obtained independent intellectual property rights of the international astronomical community.LAMOST telescope has taken the lead in the world in terms of development and implementation of combining the observation with mass survey work of thousands of celestial spectra. With the largest caliber and spectrum which has the highest rate of wide field. Druing the period between 2011 and June 2015, DR3 survey spectra obtained data set to acquire the biggest in the world currently parameters star catalog. In allusion to LAMOST the third of FGK stellar spectra data released the flow-calibration, etc. Kurucz template spectrum was used to partition the mesh, based on open source efficient R language programming supervised data processing software platform , in order that clustering center is easy to verify the theoretical parameters of the grid difference. After normalized processing of LAMOST measured spectrum, on the theoretical parameters grid with the supervised clustering validation, Euclidean distance discriminant algorithm was adopted to distinguish the similarity between the spectra. Choosing distance quantity directly described the attributes, properties of vector constructor judged the observed difference spectroscopy and the theoretical levels were selected. Experiments show that the measured spectrum of LAMOST in FGK type stellar spectra data comparisons with Kurucz theoretical template library data, which has a better consistency and accuracy in parameter measurement with the same parameters between the spectral characteristic lines. Thus, it is concluded that the spectrum measurement physical parameters of LAMOST is higher than the observation quality with excellent reliability, which provides the basis argument for improving the following stellar atmosphere models..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1951 (2017)
Microbeam X-Ray Fluorescence Spectrometry Analysis of Tiny Areas of Inner Iron-Manganese Nodules in Red Earth, Southern China
YANG Li-hui, ZHENG Xiang-min, and YE Wei
There are lots of new growths in red clay presenting dark brown color and regular or irregular shapes in southern China. Because of high Fe and Mn concentrations, these nodules are called iron-manganese nodules. As a product of soil temperature, moisture and redox conditions, these iron-manganese nodules, especially thThere are lots of new growths in red clay presenting dark brown color and regular or irregular shapes in southern China. Because of high Fe and Mn concentrations, these nodules are called iron-manganese nodules. As a product of soil temperature, moisture and redox conditions, these iron-manganese nodules, especially the circular bands in the inner nodules, were considered as a kind of environmental information carrier, and aroused widespread interest of researchers. Therefore, the study of the tiny area inside the nodules helps to understand the weathering process of the parent material and the formation process of the nodule. In this paper, using a microbeam X-Ray fluorescence spectrometer, tiny areas of inner iron-manganese nodules collected from Quaternary red earth were analyzed. The results show that the microbeam X-Ray fluorescence spectrometer can be used to analyze tiny areas of inner nodules with higher accuracy. Microscopic images of the nodule show three dark bands and two light bands alternating from the core to the edge. The X-ray fluorescence spectrum analysis indicates that the dark bands contained more Mn and less Si and Al than light bands. Combined with previous research, the dark bands represent periods of drought, and light bands represent humid periods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1955 (2017)
A Transient Measurement of NO Concentration for Diesel Engine Emissions by Tunable Laser Absorption Spectroscopy Technique
YANG Xiao-tao, FEI Hong-zi, and XIE Wen-qiang
NOx is the main pollutant substance of diesel engine. It is extremely harmful to human being and environment. NO content takes up more than 90 percent among NOx. Therefore, reasonable and accurate detection NO component of diesel engine emissions is particularly critical for the detection of NOx component. Current deteNOx is the main pollutant substance of diesel engine. It is extremely harmful to human being and environment. NO content takes up more than 90 percent among NOx. Therefore, reasonable and accurate detection NO component of diesel engine emissions is particularly critical for the detection of NOx component. Current detection method can not reflect the real situation in time because of using sampling analysis. As a new testing technique, optical detection method has been applied in many fields. This paper combines the optical detection method to investigate TLAS technique for NO concentration under steady and transient process. By simulating the situation of NO concentration changes, the feasibility of this method to apply in the diesel engines verified. An inter-band cascade laser whose center wavelength is 5263 nm is chosen for detection. A gas compounding system is devised to obtain different concentration mixing gas. Matching the test sample gas of different concentrations with high purity NO as the measured gas is carried out with N2 as the background gas. In the steady measurement, respectively match the concentrations of 500, 1 000 and 2 000 ppm to conduct experiment. A relative error is less than 1%, and the maximum absolute error is 115 ppm. In the transient measurement, experiment is conducted respectively in the process with concentration increasing and decreasing. Besides the situation of the concentration change in the chamber is measured at real time. A maximum relative error of 52% is realized with a time resolution of 1ms. With the system we devised, a transient measurement of NO concentration can be realized. This method can be applied in the diesel engine, which is good for the study of the diesel engines emissions content..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1960 (2017)
A Selective Resonance Rayleigh Scattering Method for Chiral Recognition of Carnitine Enantiomers Based on Cu2+ Functionalized Gold Nanoparticles
ZHAO Yan-mei, WU Huan, ZENG Xiao-qing, GUO Yuan, YUAN Hai-yan, HUANG Yun-mei, TAN Xuan-ping, ZHANG Lei, and YANG Ji-dong
A simple protocol to simultaneously determinate chiral enantiomers without separation is of great significance. Herein, we reported a method for chiral recognition was proposed. Cu2+ functionalized gold nanoparticles (Au NPs) was used as a sensor for carnitine enantiomers based on the resonance Rayleigh Scattering (RRSA simple protocol to simultaneously determinate chiral enantiomers without separation is of great significance. Herein, we reported a method for chiral recognition was proposed. Cu2+ functionalized gold nanoparticles (Au NPs) was used as a sensor for carnitine enantiomers based on the resonance Rayleigh Scattering (RRS) spectral technique. The RRS intensity of Au NPs is very weak, while RRS highly increased in the presence of Cu2+. More interestingly, carnitine enantiomers could quench the RRS intensities of Cu2+-Au NPs system, and they had different quenching degree. In the optimum experimental conditions, good linear relation, high correlation coefficient and low detection limit could be obtained. In addition, this proposed method could obtain enantiomer ratios and enantiomer fraction of carnitine enantiomers. And the applicability of the chiral recognition of carnitine enantiomers mixtures in capsule samples had been demonstrated. Particularly, this method does not require complicated chiral modification and excels through its low-cost, sensitivity, enantioselectivity, simplicity and good availability of materials..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1965 (2017)
Impact of EGR Rate on Soot Nanostructure from a Diesel Engine Fueled with Biodiesel
WANG Zhong, YANG Fang-ling, ZHANG Jian, ZHAO Yang, and QU Lei
A specific nanostructure analysis was performed on the soot derived from diesel engine fueled with biodiesel under different rate of exhaust gas. The experimental instruments used in this study included an 186FA engine bench, a full-flow dilution constant volume sampling system, and a laser Raman spectrometer. In the eA specific nanostructure analysis was performed on the soot derived from diesel engine fueled with biodiesel under different rate of exhaust gas. The experimental instruments used in this study included an 186FA engine bench, a full-flow dilution constant volume sampling system, and a laser Raman spectrometer. In the engine bench test, biodiesel soot under several EGR rates were collected from the exhaust gas with the Micro-Orifice Uniform Deposit Impactor (MOUDI). Then, a laser Raman spectrometer was utilized in order to explore the nanostructure of biodiesel soot. The first-order Raman spectra have been analyzed by curve fit with five band combination and the obtained spectral parameters were discussed. The results revealed that 30% EGR rate had the widest FWHM representing strongest chemical heterogeneity and most material types in biodiesel soot, next was 15% EGR rate, and no EGR was the last. While EGR rate climbed from 0 to 30%, ID/IG gradually increased, which suggested that ordered graphitic structure reduce and the degree of graphitization decreased. In addition, ID1/ID2 were located about from 8 of 0% EGR to 4 of 15% and 30% EGR, suggesting a general transformation from vacancy defect to defect at graphene layer edges. Furthermore, crystallite dimension reduced when EGR rate raised. However, C—C bond length seemed no fluctuation. Besides, there was no obvious difference of C—C bond length between biodiesel soot and typical carbon graphite. In summary, the nanostructure of biodiesel soot under high EGR rate tended to have low degree of graphitization and high oxidative reactivity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1973 (2017)
Macro- and Micro-Elements in Tea (Camellia sinensis) Leaves from Anhui Province in China with ICP-MS Technique: Levels and Bioconcentration
PENG Chuan-yi, ZHU Xiao-hui, XI Jun-jun, HOU Ru-yan, and CAI Hui-mei
The aim of this study was to analyze levels and bioconcentration potential of 4 macro-elements (Ca, K, Mg, P) and 7 micro-elements (Al, Mn, Fe, Cu, Zn, Cd and Pb) in tea leaves collected from tea orchards in Anhui, China by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the most abundantThe aim of this study was to analyze levels and bioconcentration potential of 4 macro-elements (Ca, K, Mg, P) and 7 micro-elements (Al, Mn, Fe, Cu, Zn, Cd and Pb) in tea leaves collected from tea orchards in Anhui, China by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the most abundant elements in tea young leaves were Ca, K, Mg and P (Ⅰ, >30 mg·g-1), followed by Al, Mn, Zn and Fe (Ⅱ, 02～30 mg·g-1), Cu, Pb and Cd (Ⅲ, <0.05 mg·g-1), while in mature leaves were Ca, K, Mg and Al (Ⅰ, >30 mg·g-1), followed by P, Mn, Zn and Fe (Ⅱ, 02～30 mg·g-1), Cu, Pb and Cd (Ⅲ, <005 mg·g-1). P and Mn were highly bioconcentrated, Cu, Pb and Cd in tea leaves were found to be below the legal limits. Cluster analysis demonstrated that there is no significant difference in the mineral composition between two tea cultivar..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1980 (2017)
Ag NPS/g-C3N4 Nanosheets Nanocomposites Used for SERS Nanosensors
YU Qing-bo, HU Kun, WANG Cui-ping, and LI Xian-hua
The graphite-like carbon nitride (g-C3N4) nanosheets with oxygen-containing functional groups, characterized by with XRD, FTIR and XPS, were obtained by applying chemical oxidation of bulk g-C3N4. The oxygen-containing functional groups not only can be used as anchoring sites for silver nanoparticles (Ag NPs), but alsoThe graphite-like carbon nitride (g-C3N4) nanosheets with oxygen-containing functional groups, characterized by with XRD, FTIR and XPS, were obtained by applying chemical oxidation of bulk g-C3N4. The oxygen-containing functional groups not only can be used as anchoring sites for silver nanoparticles (Ag NPs), but also help the formation of high scatter for Ag NPs in Ag NPS/g-C3N4 nanosheets nanocompposites. The weight percentage of Ag NPS in the prepared nanocomposites can be controlled by adding silver nitrate. The Ag NPS/g-C3N4 nanosheets nanocompposites are developed as a superior sensor for the detection of Co2+ ions, which are based upon Raman intensity response of g-C3N4 nanosheets to Co2+ ions. With comparison, it was found that Raman signal increase as the increasing of the concentration in Co2+. Results from the weight percentage sensitivity investigations show that Ag NPS content of 73% in nanocomposites have very low limits of detection (10-9 mol·L-1 for Co2+) in contrast with other Ag NPS content. The sensors also exhibit greater selectivity for Co2+ ions than the other metal ions (Cd2+, Cu2+ and Zn2+). The mechanism is proposed. The localized electromagnetic field is produced around the aggregated Ag NPs with the complexation between Co2+ and N/NH groups in g-C3N4 occurs, so the increase of SERS signal in the intensity can be observed. It is anticipated that Ag NPS/g-C3N4 nanosheets nanocomposites can be a new class of promising material for fabricating SERS sensors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1987 (2017)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 1 (2017)
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