Journals >Spectroscopy and Spectral Analysis
Contents
2016
Volume: 36 Issue 3
56 Article(s)
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Research Article
Radiation Environment Study of Near Space in China Area
MEI Xiao-dong, SUN Ji-lin, LI Zheng-qiang, CHEN Xing-feng, XING Jin, XU Hua, QIE Li-li, L Yang, LI Ming, and LIU Li
Aerospace activity in near space (20~50 km) has become a research hotspot for aviation big countries worldwide. Solar radiation study, as the prerequisite to carry out aerospace activity, is facing the barrier of lacking of observation in near space layer. Ozone is the most important factor that affects radiation valueAerospace activity in near space (20~50 km) has become a research hotspot for aviation big countries worldwide. Solar radiation study, as the prerequisite to carry out aerospace activity, is facing the barrier of lacking of observation in near space layer. Ozone is the most important factor that affects radiation value in this layer. Based on ECMWF reanalysis data, this input key parameter and its horizontal, vertical and temporal characteristics are analyzed with results showing obvious regional features in temporal-spatial distribution and varieties. With meteorological data and surface parameters, near space over China is divided into 5 parts. Key factors’ value is confirmed over each division. With SBDART radiation transfer model, solar radiation and ultraviolet radiation simulation in near space are conducted separately. Results show that it is influenced by latitude, total ozone and its vertical distribution, radiation varies under complex rules. The average year and monthly solar radiation strengthens changes with latitude reduction, while annual range changes reversely. Air absorbing is related to latitude and land-sea contrast and shows different values and seasonal variations. The ultraviolet radiation over South China Sea reaches its maximum value and minimum annual range, as well as minimum monthly range with value strengthening in summer and weakening in winter. In other areas radiation increases in summer while weakens in winter, monthly range shows double peaks with higher value in spring and autumn, lower in summer and winter. Air absorption in ultraviolet radiation is influenced by multiple factors, vertical varieties over areas besides South China Sea enhance in summer time. The vertical changes of monthly ranges affected by air absorption show consistence in higher and lower layer in June and July, while in other months ranges are bigger in higher layer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 609 (2016)
Correction Method of Atmospheric Scattering Effect Based on Three Spectrum Bands
YE Han-han, WANG Xian-hua, JIANG Xin-hua, and BU Ting-ting
As a major error of CO2 retrieval, atmospheric scattering effect hampers the application of satellite products. Effect of aerosol and combined effect of aerosol and ground surface are important source of atmospheric scattering, so it needs comprehensive consideration of scattering effect from aerosol and ground surfaceAs a major error of CO2 retrieval, atmospheric scattering effect hampers the application of satellite products. Effect of aerosol and combined effect of aerosol and ground surface are important source of atmospheric scattering, so it needs comprehensive consideration of scattering effect from aerosol and ground surface. Based on the continuum, strong and weak absorption part of three spectrum bands O2-A, CO2 1.6 μm and 2.06 μm, information of aerosol and albedo was analyzed, and improved full physics retrieval method was proposed, which can retrieve aerosol and albedo simultaneously to correct the scattering effect. Simulation study on CO2 error caused by aerosol and ground surface albedo CO2 error by correction method was carried out. CO2 error caused by aerosol optical depth and ground surface albedo can reach up to 8%, and CO2 error caused by different types of aerosol can reach up to 10%, while these two types of error can be controlled within 1% and 2% separately by this correction method, which shows that the method can correct the scattering effect effectively. Through evaluation of the results, the potential of this method for high precision satellite data retrieval is obvious, meanwhile, some problems which need to be noticed in real application were also pointed out..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 618 (2016)
The Diagnostics of Detonation Flow External Field Based on Multispectral Absorption Spectroscopy Technology
L Xiao-jing, LI Ning, and WENG Chun-sheng
Compared with traditional sampling-based sensing method, absorption spectroscopy technology is well suitable for detonation flow diagnostics, since it can provide with us fast response, nonintrusive, sensitive solution for situ measurements of multiple flow-field parameters. The temperature and concentration test resulCompared with traditional sampling-based sensing method, absorption spectroscopy technology is well suitable for detonation flow diagnostics, since it can provide with us fast response, nonintrusive, sensitive solution for situ measurements of multiple flow-field parameters. The temperature and concentration test results are the average values along the laser path with traditional absorption spectroscopy technology, while the boundary of detonation flow external field is unknown and it changes all the time during the detonation engine works, traditional absorption spectroscopy technology is no longer suitable for detonation diagnostics. The trend of line strength with temperature varies with different absorption lines. By increasing the number of absorption lines in the test path, more information of the non-uniform flow field can be obtained. In this paper, based on multispectral absorption technology, the reconstructed model of detonation flow external field distribution was established according to the simulation results of space-time conservation element and solution element method, and a diagnostic method of detonation flow external field was given. The model deviation and calculation error of the least squares method adopted were studied by simulation, and the maximum concentration and temperature calculation error was 20.1% and 3.2%, respectively. Four absorption lines of H2O were chosen and detonation flow was scanned at the same time. The detonation external flow testing system was set up for the valveless gas-liquid continuous pulse detonation engine with the diameter of 80 mm. Through scanning H2O absorption lines with a high frequency of 10 kHz, the on-line detection of detonation external flow was realized by direct absorption method combined with time-division multiplexing technology, and the reconstruction of dynamic temperature distribution was realized as well for the first time, both verifying the feasibility of the test method. The test results show that both of th temperature and H2O concentration rose with the arrival of detonation wave. With the increase of the vertical distance between the detonation tube nozzle and the laser path, the time of temperature and concentration coming to the peak delayed, and the temperature variation trend tended to slow down. At 20 cm from detonation tube nozzle, the maximum temperature hit 1 329 K and the maximum H2O concentration of 0.19 occurred at 4 ms after ignition. The research can provide with us the support for expanding the detonation test field with absorption spectroscopy technology, and can also help to promote the detonation mechanism research and to enhance the level of detonation engine control technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 624 (2016)
A Method to Measure the Velocity of Fragments of Large Equivalence Explosion Field Based on Explosion Flame Spectral Analysis
LIU Ji, YU Li-xia, ZHANG Bin, ZHAO Dong-e, LIU Xiao-yan, and WANG Heng-fei
The deflagration fire lasting for a long time and covering a large area in the process of large equivalent explosion makes it difficult to obtain velocity parameters of fragments in the near-field. In order to solve the problem, it is proposed in this paper a photoelectric transceiver integrated method which utilize laThe deflagration fire lasting for a long time and covering a large area in the process of large equivalent explosion makes it difficult to obtain velocity parameters of fragments in the near-field. In order to solve the problem, it is proposed in this paper a photoelectric transceiver integrated method which utilize laser screen as the sensing area. The analysis of three different types of warhead explosion flame spectral distribution of radiation shows that 0.3 to 1.0 μm within the band is at relatively low intensity. On the basis of this, the optical system applies the principle of determining the fixed distance by measuring the time and the reflector technology, which consists of single longitudinal mode laser, cylindrical Fresnel lens, narrow-band filters andhigh-speed optical sensors, etc. The system has its advantage, such as transceiver, compact structure and combination of narrowband filter and single longitudinal mode laser, which can stop the spectrum of fire from suppressing the interference of background light effectively. Large amounts of experiments in different models and equivalent have been conducted to measure the velocity of difference kinds of warheads, obtaining higher signal-to-noise ratio of the waveform signal after a series of signal de-noising and recognition through NI company data acquisition and recording system. The experimental results show that this method can complete the accurately test velocity of fragments around center of the explosion. Specifically, the minimum size of fragments can be measured is 4 mm while the speed can be obtained is up to 1 200 m·s-1 and the capture rate is better than 95% comparing with test results of target plate. At the same time, the system adopts Fresnel lenses-transparent to form a rectangular screen, which makes the distribution of rectangular light uniform in vertical direction, and the light intensity uniformity in horizontal direction is more than 80%. Consequently, the system can distinguish preliminarily the correspondence between the velocity and the sizes of prefabricated fragments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 631 (2016)
Study on the Properties of the Pc-Si Films Prepared by Magnetron Co-Sputtering at Low Temperature
DUAN Liang-fei, YANG Wen, ZHANG Li-yuan, LI Xue-ming, CHEN Xiao-bo, and YANG Pei-zhi
The polycrystalline silicon thin films play an important role in the field of electronics. In the paper, α-SiAl composite membranes on glass substrates was prepared by magnetron co-sputtering. The contents of Al radicals encapsulated in the α-Si film can be adjusted by changing the Al to Si sputtering power ratios. TheThe polycrystalline silicon thin films play an important role in the field of electronics. In the paper, α-SiAl composite membranes on glass substrates was prepared by magnetron co-sputtering. The contents of Al radicals encapsulated in the α-Si film can be adjusted by changing the Al to Si sputtering power ratios. The as-prepared α-Si films were converted into polycrystalline films by using a rapid thermal annealing (RTP) at low temperature of 350 ℃ for 10 minutes in N2 atmosphere. An X-ray diffractometer, and Raman scattering and UV-Visible-NIR Spectrometers were used to characterize the properties of the Pc-Si films. The influences of Al content on the properties of the Pc-Si films were studied. The results showed that the polycrystalline silicon films were obtained from α-SiAl composite films which were prepared by magnetron co-sputtering at a low temperature following by a rapid thermal annealing. The grain size and the degree of crystallization of the Pc-Si films increased with the increase of Al content, while the optical band gap was reduced. The nc-Si films were prepared when the Al to Si sputtering power ratio was 0.1. And a higher Crystallization rate (≥85%) of polycrystalline silicon films were obtained when the ratio was 0.3. The band gaps of the polycrystalline silicon films can be controlled by changing the aluminum content in the films..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 635 (2016)
Polarization Modeling and Analysis of Light Scattering Properties of Multilayer Films on Slightly Rough Substrate
CAO Hui, GAO Jun, WANG Ling-mei, and WANG Chi
To satisfy the demand of multilayer films on polarization detection, polarized bidirectional reflectance distribution function of multilayer films on slightly rough substrate is established on the basis of first-order vector perturbation theory and polarization transfer matrix. Due to the function, light scattering polTo satisfy the demand of multilayer films on polarization detection, polarized bidirectional reflectance distribution function of multilayer films on slightly rough substrate is established on the basis of first-order vector perturbation theory and polarization transfer matrix. Due to the function, light scattering polarization properties are studied under multi-factor impacts of two typical targets-monolayer anti-reflection film and multilayer high-reflection films. The result shows that for monolayer anti-reflection film, observing positions have a great influence on the degree of polarization, for the left of the peak increased and right decreased compared with the substrate target. Film target and bare substrate can be distinguished by the degree of polarization in different observation angles. For multilayer high-reflection films, the degree of polarization is significantly associated with the number and optical thickness of layers at different wavelengths of incident light and scattering angles. With the increase of the layer number, the degree of polarization near the mirror reflection area decreases. It reveals that the calculated results coincide with the experimental data, which validates the correctness and rationality of the model. This paper provides a theoretical method for polarization detection of multilayer films target and reflection stealth technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 640 (2016)
Influence of MnO3 on Photoelectric Performance in Organic Light
GUAN Yun-xia, CHEN Li-jia, CHEN Ping, FU Xiao-qiang, and NIU Lian-bin
Organic Light Emitting Diodes (OLEDs) has been a promising new research point that has received much attention recently. Emission in a conventional OLED originates from the recombination of carriers (electrons and holes) that are injected from external electrodes. In the device, Electrons, on the other hand, are injectOrganic Light Emitting Diodes (OLEDs) has been a promising new research point that has received much attention recently. Emission in a conventional OLED originates from the recombination of carriers (electrons and holes) that are injected from external electrodes. In the device, Electrons, on the other hand, are injected from the Al cathode to an electron-transporting layer and travel to the same emissive zone. Holes are injected from the transparent ITO anode to a hole-transporting layer and holes reach an emitting zone through the holetransporting layer. Electrons and holes recombine at the emissive film to form singlet excited states, followed by emissive light. It is because OLED is basically an optical device and its structure consists of organic or inorganic layers of sub-wavelength thickness with different refractive indices. When the electron and holes are injected through the electrodes, they combine in the emission zone emitting the photons. These photons will have the reflection and transmission at each interface and the interference will determine the intensity profile. The emissive light reflected at the interfaces or the metallic electrode returns to the emissive layer and affects the radiation current efficiency. Microcavity OLED can produce saturated colors and narrow the emission spetrum as a new kind of technique. In the paper, we fabricate microcavity OLED using glass substrate. Ag film acts as the anode reflector mirror; NPB serves as the hole-transporting material; Alq3 is electron-transporting material and organic emissive material; Ag film acts as cathode reflector mirror. The microcavity OLED structures named as A, B, C and D are glass/Ag（15 nm）/MoO3（x nm）/NPB（50 nm）/Alq3（60 nm）/Al（100 nm）. Here, A, x=4 nm; B, x=7 nm; C, x=10 nm; D, x=13 nm. The characteristic voltage, brightness and current of these devices are investigated in the electric field. The luminance from the Devices A, B, C and D reaches the luminance of 928, 1 369, 2 550 and 2 035 cd·m-2, respectively at 13 V. At 60 mA·cm-2, the current efficiency of the microcavity OLEDs using MnO3 are about 2.2, 2.6, 3.1 and 2.6 cd·A-2 respectively. It is found that electrons are majority carriers and holes are minority carriers in this microcavity OLEDs. MnO3 film can improve hole injection ability from 4 to 10 nm. In addition, hole injection ability is increased with the increasing thickness of the MnO3 film..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 648 (2016)
Temperature-Dependent Photoluminescence Property Studies of SiNx Films with nc-Si
LIU Jian-ping, ZHENG Yan, LIU Hai-xu, YU Wei, DING Wen-ge, and LAI Wei-dong
Silicon nitride (SiNx) films containing nanocrystalline silicon (nc-Si) were deposited on crystalline silicon substrate by facing-target sputtering technique. Thermal annealing process was performed at 450 ℃ for 50 min in a conventional furnace under FG(10%H2, 90%N2) ambient. The photoluminescece (PL) properties of theSilicon nitride (SiNx) films containing nanocrystalline silicon (nc-Si) were deposited on crystalline silicon substrate by facing-target sputtering technique. Thermal annealing process was performed at 450 ℃ for 50 min in a conventional furnace under FG(10%H2, 90%N2) ambient. The photoluminescece (PL) properties of the SiNx films with nc-Si were investigated by steady/transient PL spectra measurements by Fluorescence spectrometer with different temperatures. The PL processes could be attributed to the quantum confinement effect of nc-Si and the defects in the film. The PL peak position exhibits a small blue shift with the increasing of the excitation energy, which indicates that the PL portion of the nc-Si increased with smaller size. In addition, the PL lifetime increases and the PL intensity exhibits exponential increase as a result of the decreased temperature which supressed the nonradiative recombination process and then improved the radiative recombination. The PL lifetime of the film significantly reduces with the decreasing of the detection wavelength, which indicates that the PL process related to the the quantum confinement effect strongly depends on temperature..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 653 (2016)
Study on the Preparation of Ba3Si6O9N4∶Eu2+ Phosphor and the Characterization of Their Luminescence Properties
PAN Hua-yan, WANG Le, LUO Dong, LI Yang-hui, ZHANG Hong, and SHEN Ye
Ba3Si6O9N4∶Eu2+ phosphors were synthesized by two-step synthesis processes based on high temperature solid phase using BaSiO3 as a precursor. The influence mechanism of the Eu2+ doping concentration to the luminescence properties of Ba3Si6O9N4∶Eu2+ phosphors were mainly investigated. This paper made a comparison betweeBa3Si6O9N4∶Eu2+ phosphors were synthesized by two-step synthesis processes based on high temperature solid phase using BaSiO3 as a precursor. The influence mechanism of the Eu2+ doping concentration to the luminescence properties of Ba3Si6O9N4∶Eu2+ phosphors were mainly investigated. This paper made a comparison between the luminescence properties of Ba3Si6O9N4∶Eu2+ phosphors prepared by two-step processes and solid- state reaction method. The results showed that the Ba3Si6O9N4∶Eu2+ phosphors synthesized by two-step processes had higher purity and higher crystallinity. There exists concentration quenching in Ba3Si6O9N4∶Eu2+ phosphors for both two-step processes and solid-state reaction when the doping concentration x is more than 9%. Both the concentration quenching mechanism of Ba3Si6O9N4∶Eu2+ phosphor prepared by solid-state reaction and two-step processes is electric dipole-dipole interaction. The emission peak of Ba3Si6O9N4∶Eu2+ phosphors (peak 489 nm) prepared by two-step processes had a blue shift compared to the emission peak of Ba3Si6O9N4∶Eu2+ phosphors (peak 512nm) prepared by solid-state reaction. The emission peak of Ba3Si6O9N4∶Eu2+ phosphors prepared by two-step processes relatively close to the theoretical value (480 nm). The spectrum analysis result showed that the element component of Ba3Si6O9N4∶Eu2+ phosphors prepared by two-step processes was closer to the theoretical value, it means that the two-step processes can effectively reduce the lattice defects. The Ba3Si6O9N4∶Eu2+ phosphors synthesized by two-step processes had better thermal stability, which demonstrates to be a highly promising phosphor for white-LED applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 657 (2016)
Study on Indicator Densitometry Determination Method of Hemodynamic Parameters
LIU Guang-da, ZHOU Run-dong, ZHA Yu-tong, CAI Jing, NIU Jun-qi, GAO Pu-jun, and LIU Li-li
Measurement for hemodynamic parameters has always been a hot spot of clinical research. Methods for measuring hemodynamic parameters clinically have the problems of invasiveness, complex operation and being unfit for repeated measurement. To solve the problems, an indicator densitometry analysis method is presented basMeasurement for hemodynamic parameters has always been a hot spot of clinical research. Methods for measuring hemodynamic parameters clinically have the problems of invasiveness, complex operation and being unfit for repeated measurement. To solve the problems, an indicator densitometry analysis method is presented based on near-infrared spectroscopy (NIRS) and indicator dilution theory, which realizes the hemodynamic parameters measured noninvasively. While the indocyanine green (ICG) was injected into human body, circulation carried the indicator mixing and diluting with the bloodstream. Then the near-infrared probe was used to emit near-infrared light at 735, 805 and 940 nm wavelengths through the sufferer’s fingertip and synchronously capture the transmission light containing the information of arterial pulse wave. By uploading the measured data, the computer would calculate the ICG concentration, establish continuous concentration curve and compute some intermediate variables such as the mean transmission time (MTT) and the initial blood ICG concentration (ct0). Accordingly Cardiac Output (CO) and Circulating Blood Volume (CBV) could be calculated. Compared with the clinical “gold standard” methods of thermodilution and I-131 isotope-labelling method to measure the two parameters by clinical controlled trials, ten sets of data were obtained. The maximum relative errors of this method were 8.88% and 4.28% respectively, and both of the average relative errors were below 5%. The result indicates that this method can meet the clinical accuracy requirement and can be used as a noninvasive, repeatable and applied solution for clinical hemodynamic parameters measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 662 (2016)
Study on Different Parts of Wild and Cultivated Gentiana Rigescens with Fourier Transform Infrared Spectroscopy
SHEN Yun-xia, ZHAO Yan-li, ZHANG Ji, ZUO Zhi-tian, WANG Yuan-zhong, and ZHANG Qing-zhi
The application of traditional Chinese medicine (TCM) and their preparations have a long history. With the deepening of the research, the market demand is increasing. However, wild resources are so limited that it can not meet the needs of the market. The development of wild and cultivated samples and research on accumThe application of traditional Chinese medicine (TCM) and their preparations have a long history. With the deepening of the research, the market demand is increasing. However, wild resources are so limited that it can not meet the needs of the market. The development of wild and cultivated samples and research on accumulation dynamics of chemical component are of great significance. In order to compare composition difference of different parts (root, stem, and leaf) of wild and cultivated G. rigescens, Fourier infrared spectroscopy (FTIR) and second derivative spectra were used to analyze and evaluate. The second derivative spectra of 60 samples and the rate of affinity (the match values) were measured automatically using the appropriate software (Omnic 8.0). The results showed that the various parts of wild and cultivated G. rigescens. were high similar the peaks at 1 732, 1 643, 1 613, 1 510, 1 417, 1 366, 1 322, 1 070 cm-1 were the characteristic peak of esters, terpenoids and saccharides, respectively. Moreover, the shape and peak intensity were more distinct in the second derivative spectrum of samples. In the second derivative spectrum range of 1 800~600 cm-1, the fingerprint characteristic peak of samples and gentiopicroside standards were 1 679, 1 613, 1 466, 1 272, 1 204, 1 103, 1 074, 985, 935 cm-1. The characteristic peak intensity of gentiopicroside of roots of wild and cultivated samples at 1 613 cm-1(C—C) was higher than stems and leaves which indicated the higher content of gentiopicroside in root than in stem and leaves. Stems of wild samples at 1 521, 1 462 and 1 452 cm-1 are the skeletal vibration peak of benzene ring of lignin, and the stem of cultivated sample have stronger peak than other samples which showed that rich lignin in stems. The iInfrared spectrum of samples were similar with the average spectral of root of wild samples, and significant difference was found for the correlation between second derivative spectrum of samples and average spectral of wild samples root, and the sequence of similarity was root>stem>leaf. Therefore, FTIR combined with second derivative spectra was an express and comprehensive approach to analyze and evaluate in the imperceptible differences among different parts of wild and cultivated of G. rigescens..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 667 (2016)
Rapid FTIR-ATR Method for the Quantification of Bitumen Property
TANG Jie-qiong, MA Qing-feng, SHI Jing-tao, YUAN Hong-fu, SONG Chun-feng, XIE Jin-chun, and LI Xiao-yu
The quality of bitumen directly affects road performance and road life. Traditional analytical methods for wax content, softening point and penetration of bitumen are tedious and time-consuming. A new fast method, with which the three properties can be determined at same time, is proposed in this paper. The spectra of The quality of bitumen directly affects road performance and road life. Traditional analytical methods for wax content, softening point and penetration of bitumen are tedious and time-consuming. A new fast method, with which the three properties can be determined at same time, is proposed in this paper. The spectra of 220 bitumen were collected and their wax content, softening point and penetration data were determined according to the standard JTJ052—2000. The quantitative calibration models for wax content, softening point and penetration were established using partial least squares (PLS), with SECV 0.13, 0.88, 3.18 and SEP 0.14, 1.06, 3.90, less than the reproducibility error stipulated in the standard method. Three samples were in random selected to test the repeatability, the results met the precision requirement of the standard method. With its advantages of better repeatability, fast, easy operation, the new method can be used as an alternative for the determination of wax content, softening point and penetration of bitumen..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 672 (2016)
FTIR Spectroscopic Characterization of Material Composition in Functional Leaf of Cotton under Stress of Potassium and Boron
WU Xiu-wen, HAO Yan-shu, LEI Jing, and JIANG Cun-cang
Potassium (K) and boron (B) are essential nutrient elements for plants, and the elements play an important role for plant growth, development and physiological metabolism. Cotton has a higher demand for K and B; K deficiency or B deficiency often occurs in cotton though. To reveal the component changes in functional lePotassium (K) and boron (B) are essential nutrient elements for plants, and the elements play an important role for plant growth, development and physiological metabolism. Cotton has a higher demand for K and B; K deficiency or B deficiency often occurs in cotton though. To reveal the component changes in functional leaf of cotton under K and B stress and investigate effects on material composition from K and B. A pot experiment was conducted at Huazhong Agricultural University. (1) the characteristic peaks at 1 546.86,1 438.85, 1 153.39 and 1 024.17 cm-1 disappeared due to B deficiency, and relative absorbance of other characteristic peaks was decreased compared with normal, which suggested that the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in cotent when lack of K. (2) the relative absorbance of all characteristic peaks was increased in the B-deficient cotton leaves compared with normal, suggesting B deficiency leads to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates because of the hindered transportation. (3) lack of both potassium and boron, induced significant changes to both the locations and relative absorbance of characteristic peaks, and the content of protein, and soluble sugar and other carbohydrates increased , while the content of nucleic acids and polysaccharides dropped. K deficiency led to the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in content ; B deficiency gave rise to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates; the content of protein and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped when K and B were all in short supply ..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 676 (2016)
Terahertz and Infrared Spectroscopic Investigation of Cellulose
QIU Guo-hua, ZHANG Le, and SHENTU Nan-ying
To investigate the Terahertz’s application prospect, corn, wheat husk and reed were used to detect their Terahertz Time Domain Spectroscopy, and be compared with that of cellulose powder. The experimental results show that all of their absorption peaks exist at 1.75, 1.62, 1.1, and 0.7 THz. Absorption intensity of cellTo investigate the Terahertz’s application prospect, corn, wheat husk and reed were used to detect their Terahertz Time Domain Spectroscopy, and be compared with that of cellulose powder. The experimental results show that all of their absorption peaks exist at 1.75, 1.62, 1.1, and 0.7 THz. Absorption intensity of cellulose powder, corn, wheat husk and reed were compared in some frequencies points. It finds that corn, wheat husk and reed have higher absorption intensity than cellulose powder in early frequency domain. However, absorption intensity of cellulose powder is the strongest at 1.62 THz. Cellulose content in corn, wheat husk and reed were detected by using the method of chemical analysis. The peaks of absorption coefficient are related to their cellulose content at this frequency. It shows that plant cellulose occur lattice vibration in the frequency. Deformation, bending, flexing, and other changes appear to their functional keys. Quantum chemical calculation was carried out by using density functional theory to cellulose and the structure diagram of cellulose molecular formula was obtained. It also finds some absorption peaks exist at 0.7, 1.1, and 1.75 THz. Characterization of cellulose clusters mainly includes CH2, OH, CH, and so on. Glucose hydroxyl radical on the ring is active in the cellulose chain. Where hydroxyl related chemical reaction can occur, Hydroxyl can also be integrated into the intermolecular and intramolecular hydrogen bond. Terahertz wave can promote hydrogen bond vibration. This kind of vibration is weak in the intermolecular interaction. The vibration and rotating happen in dipole transition. The crystal lattice rotates and is absorptive in low frequency, and large molecular skeleton vibrates. All of them can show different intensity and position of the absorption peak in the terahertz band. Corn and cellulose were analyzed by infrared spectrum. The reverse and vibration mode of cellulose was discussed. The absorption peak is basically in line with its theoretical calculating result. It is feasible that Terahertz Time Domain Spectroscopy can detect cellulose, and it provides a new method for the detection and judgement of cellulose in plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 681 (2016)
Preparation and Characterization of Manganese and Fluorine Co-Modified Hydroxyapatite Composite Coating
ZHANG Xue-jiao, HAO Min, QIAO Hai-xia, ZHANG Xiao-yun, HUANG Yong, NIAN Xiao-feng, and PANG Xiao-feng
Titanium and titanium alloys have been widely used as orthopedic, dental implants and cardiovascular stents owing to their superior physical properties. However, titanium surface is inherently bio-inert, thus could not form efficient osseointegration with surrounding bone tissue. Therefore, to improve the surface propeTitanium and titanium alloys have been widely used as orthopedic, dental implants and cardiovascular stents owing to their superior physical properties. However, titanium surface is inherently bio-inert, thus could not form efficient osseointegration with surrounding bone tissue. Therefore, to improve the surface property of titanium implant is significantly important in clinical application. Manganese and fluorine co-doped hydroxyapatite (FMnHAP) coatings were prepared on titanium substrate by electrochemical deposition technique. The as-prepared coatings were examined by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests. The results indicated that the FMnHAP coatings take the morphology of nanoscale-villous-like, the composite coating becomes more compact. The FTIR test indicated that the symmetry of bending vibration modes of hydroxyl changed, simulated body fluid immersion test proved that the FMnHAP coatings had induce carbonate-apatite formation, indicating that the composite coating possess excellent biocompatibility. In the electrochemical corrosion testing, the FMnHAP coatings showed stronger corrosion resistance than pure Ti..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 686 (2016)
Study on Estimation of Deserts Soil Total Phosphorus Content by Vis-NIR Spectra with Variable Selection
YANG Ai-xia, DING Jian-li, LI Yan-hong, and DENG Kai
In this paper, 300 samples of desert soil collected in the Ebinur Lake Wetland Nature Reserve of Xinjiang were used as the research subject, and the visible/near-infrared spectra data about the soil obtained with the ASD Field Spec○R 3 HR spectrometer and the data about total phosphorus in the soil obtained through cheIn this paper, 300 samples of desert soil collected in the Ebinur Lake Wetland Nature Reserve of Xinjiang were used as the research subject, and the visible/near-infrared spectra data about the soil obtained with the ASD Field Spec○R 3 HR spectrometer and the data about total phosphorus in the soil obtained through chemical analysis were used as the data sources; following Savizky-Golay smoothing, standard normal variation transformation and the first-order differential pretreatment, the combination of ant colony optimization interval partial least squares (ACO-iPLS) and genetic algorithm interval partial least squares (GA-iPLS) were employed to extract the characteristic wavelengths of the total phosphorus content in desert soil, before the partial least squares regression model for predicting the total-phosphorus content in soil was constructed; and this model was compared with the full-spectrum partial least squares model, ACO-iPLS and GA-iPLS. According to the results: through filtering with ACO-iPLS, the total-phosphorus characteristic wavebands in the desert soil were 500~700, 1 101~1 300, 1 501~1 700, and 1 901~2 100 nm; through further variable selection with GA-iPLS, 13 effective wavelengths with the minimum colinearity were selected, which were respectively: 1 621, 546, 1 259, 573, 1 572, 1 527, 564, 1 186, 1 988, 1 541, 2 024, 1 118, and 1 191 nm. According to the comparison of modeling methods, the most accurate model was the one based on the characteristic variables selected with the combination of ACO-iPLS and GA-iPLS, followed by the ones with genetic algorithm, ant colony optimization algorithm and the full spectrum method. For the total phosphorus content in soil model established with the combination of ACO-iPLS and GA-iPLS, the root mean square error of cross validation (RMSECV) and the root mean square error of prediction (RMSEP) were respectively 0.122 and 0.108 mg·g-1, and the related coefficient for cross validation (Rc) and the related coefficient for prediction (Rp) were 0.535 7 and 0.555 9, respectively. Therefore, it can be seen that the model constructed through Savizky-Golay smoothing, standard normal variation transformation and the first-order differential pretreatment and by using the combination of ACO-iPLS and GA-iPLS has simple structure, high prediction accuracy and good robustness, and can be used for estimating the total phosphorus content in desert soil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 691 (2016)
Research on Resistant Starch Content of Rice Grain Based on NIR Spectroscopy Model
LUO Xi, WU Fang-xi, XIE Hong-guang, ZHU Yong-sheng, ZHANG Jian-fu, and XIE Hua-an
A new method based on near-infrared reflectance spectroscopy (NIRS) analysis was explored to determine the content of rice-resistant starch instead of common chemical method which took long time was high-cost. First of all, we collected 62 spectral data which have big differences in terms of resistant starch content ofA new method based on near-infrared reflectance spectroscopy (NIRS) analysis was explored to determine the content of rice-resistant starch instead of common chemical method which took long time was high-cost. First of all, we collected 62 spectral data which have big differences in terms of resistant starch content of rice, and then the spectral data and detected chemical values are imported chemometrics software. After that a near-infrared spectroscopy calibration model for rice-resistant starch content was constructed with partial least squares (PLS) method. Results are as follows: In respect of internal cross validation, the coefficient of determination (R2) of untreated, pretreatment with MSC+1thD,pretreatment with 1thD+SNV were 0.920 2,0.967 0 and 0.976 7 respectively. Root mean square error of prediction（RMSEP）were 1.533 7,1.011 2 and 0.837 1 respectively. In respect of external validation, the coefficient of determination (R2) of untreated, pretreatment with MSC+1thD, pretreatment with 1thD+SNV were 0.805, 0.976 and 0.992 respectively. The average absolute error was 1.456, 0.818, 0.515 respectively. There was no significant difference between chemical and predicted values (Turkey multiple comparison), so we think near infrared spectrum analysis is more feasible than chemical measurement. Among the different pretreatment, the first derivation and standard normal variate (1thD+SNV) have higher coefficient of determination (R2) and lower error value whether in internal validation and external validation. In other words, the calibration model has higher precision and less error by pretreatment with 1thD+SNV..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 697 (2016)
Determination of Hard Rate of Alfalfa (Medicago sativa L. ) Seeds with Near Infrared Spectroscopy
WANG Xin-xun, CHEN Ling-ling, ZHANG Yun-wei, and MAO Pei-sheng
Alfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%~80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant productioAlfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%~80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant production. This experiment was designed for 121 samples of alfalfa. Seeds were collected according to different regions, harvested year and varieties. 31 samples were artificial matched as hard rates ranging from 20% to 80% to establish a model for hard seed rate by near infrared spectroscopy (NIRS) with Partial Least Square (PLS). The objective of this study was to establish a model and to estimate the efficiency of NIRS for determining hard rate of alfalfa seeds. The results showed that the correlation coefficient (R2cal) of calibration model was 0.981 6, root mean square error of cross validation (RMSECV) was 5.32, and the ratio of prediction to deviation (RPD) was 3.58. The forecast model in this experiment presented the satisfied precision. The proposed method using NIRS technology is feasible for identification and classification of hard seed in alfalfa. A new method, as nondestructive testing of hard seed rate, was provided to theoretical basis for fast nondestructive detection of hard seed rates in alfalfa..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 702 (2016)
Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique
JIANG Zhi-quan, and HU Ke-liang
In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed basedIn the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 706 (2016)
The Identification of Lettuce Varieties by Using Unsupervised Possibilistic Fuzzy Learning Vector Quantization and Near Infrared Spectroscopy
WU Xiao-hong, CAI Pei-qiang, WU Bin, SUN Jun, and JI Gang
To solve the noisy sensitivity problem of fuzzy learning vector quantization (FLVQ), unsupervised possibilistic fuzzy learning vector quantization (UPFLVQ) was proposed based on unsupervised possibilistic fuzzy clustering (UPFC). UPFLVQ aimed to use fuzzy membership values and typicality values of UPFC to update the leTo solve the noisy sensitivity problem of fuzzy learning vector quantization (FLVQ), unsupervised possibilistic fuzzy learning vector quantization (UPFLVQ) was proposed based on unsupervised possibilistic fuzzy clustering (UPFC). UPFLVQ aimed to use fuzzy membership values and typicality values of UPFC to update the learning rate of learning vector quantization network and cluster centers. UPFLVQ is an unsupervised machine learning algorithm and it can be applied to classify without learning samples. UPFLVQ was used in the identification of lettuce varieties by near infrared spectroscopy (NIS). Short wave and long wave near infrared spectra of three types of lettuces were collected by FieldSpec@3 portable spectrometer in the wavelength range of 350～2 500 nm. When the near infrared spectra were compressed by principal component analysis (PCA), the first three principal components explained 97.50% of the total variance in near infrared spectra. After fuzzy c-means (FCM) clustering was performed for its cluster centers as the initial cluster centers of UPFLVQ, UPFLVQ could classify lettuce varieties with the terminal fuzzy membership values and typicality values. The experimental results showed that UPFLVQ together with NIS provided an effective method of identification of lettuce varieties with advantages such as fast testing, high accuracy rate and non-destructive characteristics. UPFLVQ is a clustering algorithm by combining UPFC and FLVQ, and it need not prepare any learning samples for the identification of lettuce varieties by NIS. UPFLVQ is suitable for linear separable data clustering and it provides a novel method for fast and nondestructive identification of lettuce varieties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 711 (2016)
Discriminant Analysis of Lavender Essential Oil by Attenuated Total Reflectance Infrared Spectroscopy
TANG Jun, WANG Qing, TONG Hong, LIAO Xiang, and ZHANG Zheng-fang
This work aimed to use attenuated total reflectance Fourier transform infrared spectroscopy to identify the lavender essential oil by establishing a Lavender variety and quality analysis model. So, 96 samples were tested. For all samples, the raw spectra were pretreated as second derivative, and to determine the 1 750~This work aimed to use attenuated total reflectance Fourier transform infrared spectroscopy to identify the lavender essential oil by establishing a Lavender variety and quality analysis model. So, 96 samples were tested. For all samples, the raw spectra were pretreated as second derivative, and to determine the 1 750~900 cm-1 wavelengths for pattern recognition analysis on the basis of the variance calculation. The results showed that principal component analysis (PCA) can basically discriminate lavender oil cultivar and the first three principal components mainly represent the ester, alcohol and terpenoid substances. When the orthogonal partial least-squares discriminant analysis (OPLS-DA) model was established, the 68 samples were used for the calibration set. Determination coefficients of OPLS-DA regression curve were 0.959 2, 0.976 4, and 0.958 8 respectively for three varieties of lavender essential oil. Three varieties of essential oil's the root mean square error of prediction (RMSEP) in validation set were 0.142 9, 0.127 3, and 0.124 9, respectively. The discriminant rate of calibration set and the prediction rate of validation set had reached 100%. The model has the very good recognition capability to detect the variety and quality of lavender essential oil. The result indicated that a model which provides a quick, intuitive and feasible method had been built to discriminate lavender oils..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 716 (2016)
The Identification of the Origin of Chinese Wolfberry Based on Infrared Spectral Technology and the Artificial Neural Network
LI Zhong, LIU Ming-de, and JI Shou-xiang
The Fourier Transform Infrared Spectroscopy (FTIR) is established to find the geographic origins of Chinese wolfberry quickly. In the paper, the 45 samples of Chinese wolfberry from different places of Qinghai Province are to be surveyed by FTIR. The original data matrix of FTIR is pretreated with common preprocessing The Fourier Transform Infrared Spectroscopy (FTIR) is established to find the geographic origins of Chinese wolfberry quickly. In the paper, the 45 samples of Chinese wolfberry from different places of Qinghai Province are to be surveyed by FTIR. The original data matrix of FTIR is pretreated with common preprocessing and wavelet transform. Compared with common windows shifting smoothing preprocessing, standard normal variation correction and multiplicative scatter correction, wavelet transform is an effective spectrum data preprocessing method. Before establishing model through the artificial neural networks, the spectra variables are compressed by means of the wavelet transformation so as to enhance the training speed of the artificial neural networks,, and at the same time the related parameters of the artificial neural networks model are also discussed in detail. The survey shows even if the infrared spectroscopy data is compressed to 1/8 of its original data, the spectral information and analytical accuracy are not deteriorated. The compressed spectra variables are used for modeling parameters of the back-propagation artificial neural network (BP-ANN) model and the geographic origins of Chinese wolfberry are used for parameters of export. Three layers of neural network model are built to predict the 10 unknown samples by using the MATLAB neural network toolbox design error back propagation network. The number of hidden layer neurons is 5, and the number of output layer neuron is 1. The transfer function of hidden layer is tansig, while the transfer function of output layer is purelin. Network training function is trainl and the learning function of weights and thresholds is learngdm. net.trainParam.epochs=1 000, while net.trainParam.goal=0.001.The recognition rate of 100% is to be achieved. It can be concluded that the method is quite suitable for the quick discrimination of producing areas of Chinese wolfberry. The infrared spectral analysis technology combined with the artificial neural networks is proved to be a reliable and new method for the identification of the original place of Traditional Chinese Medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 720 (2016)
Baseline Correction Algorithm for Raman Spectroscopy Based on Non-Uniform B-Spline
FAN Xian-guang, WANG Hai-tao, WANG Xin, XU Ying-jie, WANG Xiu-fen, and QUE Jing
As one of the necessary steps for data processing of Raman spectroscopy, baseline correction is commonly used to eliminate the interference of fluorescence spectra. The traditional baseline correction algorithm based on polynomial fitting is simple and easy to implement, but its flexibility is poor due to the uncertainAs one of the necessary steps for data processing of Raman spectroscopy, baseline correction is commonly used to eliminate the interference of fluorescence spectra. The traditional baseline correction algorithm based on polynomial fitting is simple and easy to implement, but its flexibility is poor due to the uncertain fitting order. In this paper, instead of using polynomial fitting, non-uniform B-spline is proposed to overcome the shortcomings of the traditional method. Based on the advantages of the traditional algorithm, the node vector of non-uniform B-spline is fixed adaptively using the peak position of the original Raman spectrum, and then the baseline is fitted with the fixed order. In order to verify this algorithm, the Raman spectra of parathion-methyl and colza oil are detected and their baselines are corrected using this algorithm, the result is made comparison with two other baseline correction algorithms. The experimental results show that the effect of baseline correction is improved by using this algorithm with a fixed fitting order and less parameters, and there is no over or under fitting phenomenon. Therefore, non-uniform B-spline is proved to be an effective baseline correction algorithm of Raman spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 724 (2016)
Study on the Recognition of Liquor Age of Gujing Based on Raman Spectra and Support Vector Regression
WANG Guo-xiang, WANG Hai-yan, WANG Hu, ZHANG Zheng-yong, and LIU Jun
It is an important and difficult research point to recognize the age of Chinese liquor rapidly and exactly in the field of liquor analyzing, which is also of great significance to the healthy development of the liquor industry and protection of the legitimate rights and interests of consumers. Spectroscopy together witIt is an important and difficult research point to recognize the age of Chinese liquor rapidly and exactly in the field of liquor analyzing, which is also of great significance to the healthy development of the liquor industry and protection of the legitimate rights and interests of consumers. Spectroscopy together with the pattern recognition technology is a preferred method of achieving rapid identification of wine quality, in which the Raman Spectroscopy is promising because of its little affection of water and little or free of sample pretreatment. So, in this paper, Raman spectra and support vector regression (SVR) are used to recognize different ages and different storing time of the liquor of the same age. The innovation of this paper is mainly reflected in the following three aspects. First, the application of Raman in the area of liquor analysis is rarely reported till now. Second, the concentration of studying the recognition of wine age, while most studies focus on studying specific components of liquor and studies together with the pattern recognition method focus more on the identification of brands or different types of base wine. The third one is the application of regression analysis framework, which cannot be only used to identify different years of liquor, but also can be used to analyze different storing time, which has theoretical and practical significance to the research and quality control of liquor. Three kinds of experiments are conducted in this paper. Firstly, SVR is used to recognize different ages of 5, 8, 16 and 26 years of the Gujing Liquor; secondly, SVR is also used to classify the storing time of the 8-years liquor; thirdly, certain group of train data is deleted form the train set and put into the test set to simulate the actual situation of liquor age recognition. Results show that the SVR model has good train and predict performance in these experiments, and it has better performance than other non-liner regression method such as the Partial Least Squares Regression (PLS) method, and can also be applied in the practice of liquor analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 729 (2016)
Study on the Rapid Detection of Triazophos Residues in Flesh of Navel Orange by Using Surface-Enhanced Raman Scattering
WANG Xiao-bin, WU Rui-mei, LING Jing, LIU Mu-hua, ZHANG Lu-ling, LIN Lei, and CHEN Jin-yin
Surface enhanced Raman spectroscopy (SERS) and quick pre-treatment technology were used to detect triazophos residues in flesh of navel orange. Quantitative analysis model was developed by partial least squares (PLS) algorithm. SERS of different concentration (0.5 to 20 mg·L-1) triazophos juice solution with fleshSurface enhanced Raman spectroscopy (SERS) and quick pre-treatment technology were used to detect triazophos residues in flesh of navel orange. Quantitative analysis model was developed by partial least squares (PLS) algorithm. SERS of different concentration (0.5 to 20 mg·L-1) triazophos juice solution with flesh extract as the matrix were collected by laser Raman spectrometer. Three preprocessing methods such as normalization, MSC and SNV were used to optimize Raman signals and PLS models were set up. The results showed that minimum detection concentration for triazophos in navel orange below 0.5 mg·L-1. The model built with normalization pre-processing gave the best result; the values of correlation (Rp) and Root mean square error of prediction set (RMSEP) were 1.38 and 0.976 6, respectively. The predict recoveries were 95.97%～103.18% and the absolute values of relative errors were below 5%. T-test (t=－0.018) showed that there was no significant difference between the true values and prediction values. This study demonstrates that this method is accurate and reliable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 736 (2016)
NIR-SERS Spectra Detection of Cytidine on Nano-Silver Films
ZHANG De-qing, LIU Ren-ming, ZHANG Guo-qiang, ZHANG Yan, XIONG Yang, ZHANG Chuan-yun, LI Lun, and SI Min-zhen
The polyvinyl alcohol (PVA) protected silver glass-like nanostructure (PVA-Ag-GNS) with high surface-enhanced Raman scattering (SERS) activity was prepared and employed to detect the near-infrared surface enhanced Raman scattering (NIR-SERS) spectra of cytidine aqueous solution (10-2～10-8 mol·L-1). In the work, thThe polyvinyl alcohol (PVA) protected silver glass-like nanostructure (PVA-Ag-GNS) with high surface-enhanced Raman scattering (SERS) activity was prepared and employed to detect the near-infrared surface enhanced Raman scattering (NIR-SERS) spectra of cytidine aqueous solution (10-2～10-8 mol·L-1). In the work, the near-infrared laser beam (785 nm) was used as the excitation light source. The experiment results show that high-quality NIR-SERS spectra were obtained in the ranges of 300 to 2 000 cm-1 and the detection limit of cytidine aqueous solution was down to 10-7 mol·L-1. Meanwhile, the PVA-Ag-GNS shows a high enhancement factor (EF) of ～108. In order to test the optical reproducibility of PVA-Ag-GNS, ten samples of cytidine aqueous solution (10-2～10-5 mol·L-1) had been dropped onto the surface of PVA-Ag-GNS respectively. Meanwhile, these samples were measured by the portable Raman spectrometer. As a result, the PVA-Ag-GNS demonstrated good optical reproducibility in the detection of cytidine aqueous solution. In addition, to explain the reason of enhancement effect, the ultraviolet-visible (UV-Vis) extinction spectrum and scanning electron microscope (SEM) of cytidine molecules adsorbed on the surface of PVA-Ag-GNS were measured. There is plasmon resonance band at 800 nm in the UV-Vis extinction spectrum of the compound system. Therefore, when the near-infrared laser beam (785 nm) was used as excitation light source, the compound system may produce strongly surface plasmon resonance (SPR). According to the SEM of PVA-Ag-GNS, there are much interstitial between the silver nanoparticles. So NIR-SERS is mainly attributed to electromagnetic (EM) fields associated with strong surface plasmon resonance. At last, the geometry optimization and pre-Raman spectrum of cytidine for the ground states were performed with DFT, B3LYP functional and the 6-311G basis set, and the near-infrared laser with wavelength of 785 nm was employed in the pre-Raman spectrum calculation process. The calculation results without imaginary frequency and the results match pretty well with the experimental Raman spectrum. At the same time, the assignations of Raman bands and adsorption behaviors of cytidine molecules on the surface of PVA-Ag-GNS are also discussed. According to our experiment and calculations, cytidine molecules mainly adsorbed on silver nanoparticles via the ribose moiety and amino group may get close to the local electromagnetic field..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 743 (2016)
Application of Cationic Aluminum Phthalocyanine, a Red-Emitting Fluorescent Probe, for Sensitive Quantitative Analysis of RNA at Nanogram Level
GUO Meng-lin, YANG Hui-qing, HUANG Ping, CHEN Lin, and LI Dong-hui
Tetrasubstituted trimethyl ammonium iodide aluminum phthalocyanine (TTMAAlPc), a positively charged phthalocyanine compound, is an emerging and potentially useful red-emitting fluorescence probe. The study showed that the fluorescence of TTMAAlPc could be quenched by RNA with high efficiency in weak alkaline media, andTetrasubstituted trimethyl ammonium iodide aluminum phthalocyanine (TTMAAlPc), a positively charged phthalocyanine compound, is an emerging and potentially useful red-emitting fluorescence probe. The study showed that the fluorescence of TTMAAlPc could be quenched by RNA with high efficiency in weak alkaline media, and the degree of quenching has a linear relationship with RNA in a wide concentration range. The mechanism of quenching behavior of RNA on TTMAAlPc was discussed. It was attributed by the static interaction between RNA and TTMAAlPc, and the assembly of TTMAAlPc induced by RNA. Based on this new discovery, a novel method for quantitative determination of RNA at nanogram level has been established. The factors, including the pH of medium, buffer system, reaction time, reaction temperature, the usage of TTMAAlPc as well as the interferences, which affected the determination, were investigated and discussed. Under optimum conditions, the linear range of the calibration curve was 7.71~1 705.57 ng·mL-1. The detection limit for RNA was 1.55 ng·mL-1. This method has been applied to the analysis of practical samples with satisfied results. The constructed method is of high sensitivity and has a wide linear range, it also showed strong ability in the tolerance of foreign substances from anions, cations, surfactants and vitamins, all of which are common interferences encountered in the determination of RNA. Besides, it is the first report that the fluorescence quantum yield of TTMAAlPc has been measured at different pH by reference method in this work. The achieved data indicated that the fluorescence quantum yield of TTMAAlPc is larger than 20% and it keeps constant in a wide range of acidity, implying that TTMAAlPc is a high-quality red-emitting fluorescence probe, it has great potential for practical applications, thus is worthy of further study. This work expands the application of phthalocyanine compound in analytical sciences..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 749 (2016)
The Establishment of the Method of the Fiber Optic Chemical Sensor Synchronous Absorption-Fluorescence
ZHANG Li-hua, and Arkin IBURAIM
A new method of simultaneously measuring fiber-optic chemical sensor absorption spectrum and fluorescence spectrum is established. Make synchronous absorption-fluorescence cuvette, establish synchronous absorption-fluorescence spectrometry instrumentation combined by fiber optic chemical sensor technology, measure the A new method of simultaneously measuring fiber-optic chemical sensor absorption spectrum and fluorescence spectrum is established. Make synchronous absorption-fluorescence cuvette, establish synchronous absorption-fluorescence spectrometry instrumentation combined by fiber optic chemical sensor technology, measure the synchronous absorption-fluorescence spectrums of solutions of rhodamine B, vitamin B2 and vitamin B6, compared by absorption spectroscopy measured by traditional UV-Visible photometric method and fluorescence spectroscopy measured by traditional fluorescence method. Synchronous absorption-fluorescence method measure absorption spectrums and fluorescence spectrums the same to traditional photometric and fluorescence spectroscopy of rhodamine B, vitamin B2 and vitamin B6. The maximum wavelength of fluorescence intensity method has high accuracy relatively compared with fluorescence, but the maximum wavelength of absorption has a slight deviation. Synchronous absorption-fluorescence method means simultaneously measure the absorption spectrums and fluorescence spectrums of the fluorescent substance, making two spectrums to one. The method measured the maximum emission wavelength with high accuracy, though in measuring maximum absorption wavelength there is a slight deviation, but it is worth further studying..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 755 (2016)
Study on the Hydrothermal Synthesis and Fluorescence of LaF3∶Tb3+, Ce3+ Nanocrystals
XU Shi-hua, HUANG Zhong-jing, LIU Guo-cong, and WEI Qing-min
LaF3∶Tb3+, Ce3+ nanocrystals were prepared with hydrothermal method with the help of cetyltrimethyl ammonium bromide (CTAB). The effects of pH values of the solution, Ce3+/Tb3+ ratio value and reaction time on the luminescent properties were investigated. XRD analysis shows that the as-prepared samples possess hexagonaLaF3∶Tb3+, Ce3+ nanocrystals were prepared with hydrothermal method with the help of cetyltrimethyl ammonium bromide (CTAB). The effects of pH values of the solution, Ce3+/Tb3+ ratio value and reaction time on the luminescent properties were investigated. XRD analysis shows that the as-prepared samples possess hexagonal phase and their main diffraction peaks of samples are similar to the standard card (JCPDS 32－0483). Compared with pure LaF3, the main diffraction peaks of the doped samples have a slight shift, showing existing isomorphous substitution between La3+ and the doped rare earth ions in parent lattice of LaF3. It is found from TEM results that the as-prepared samples have good crystallinity and their average grain sizes change in the range of 20～50 nm. The excitation spectra indicate that the stronger excitation spectrum peaks exist at 250 nm, which is assigned to the transition of 4f→5d from Ce3+. When activated at 250 nm, all LaF3∶Tb3+, Ce3+ nanocrystals possess weak blue emission at 490 nm (electric dipole transition, 5D4→7F6) and good green emission at 543 nm (magnetic dipole transition, 5D4→7F5). As the Ce3+/Tb3+ ratio increases, the fluorescence intensities increase at first and then weaken, and reach the strongest green emission at nCe3+/nTb3+=4. The pH values have some influence on the colors and intensities of the LaF3∶Tb3+, Ce3+ nanocrystals. The sample prepared at pH 9 presents the best color, while the one at pH 7 exhibits the strongest green emission. Besides, increasing reaction time is helpful to improve color purity of sample and enhance its green emission..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 759 (2016)
Intermolecular Interactions between Cytisine and Bovine Serum Albumin: A Synchronous Fluorescence Spectroscopic Analysis and Molecular Docking Research
WU Yu-hang, HAN Zhong-bao, MA Jia-ze, HE Yan, LIU Li-yan, XIN Shi-gang, and YU Zhan
Cytisine (Cy) is one of the alkaloids that exist naturally in the plant genera Laburnum of the family Fabaceae. With strong bioactivities, Cy is commercialized for smoking cessation for years. In this work, the study of intermolecular interactions between Cy and bovine serum albumin (BSA) was performed by applying fluoCytisine (Cy) is one of the alkaloids that exist naturally in the plant genera Laburnum of the family Fabaceae. With strong bioactivities, Cy is commercialized for smoking cessation for years. In this work, the study of intermolecular interactions between Cy and bovine serum albumin (BSA) was performed by applying fluorescence spectroscopic methods under simulated physiological conditions. The mechanism of fluorescence quenching of BSA by Cy was also studied. Parameters such as bathing temperature, time and solution pH were investigated to optimize the fluorescence quenching. The binding type, binding ratio and binding constant between BSA and Cy were calculated by using the Stem-Volmer equation. Experimental results indicated that Cy can quench the fluorescent emission of BSA statically by forming a 1∶1 type non-covalent complex and the binding constant is 5.6×103 L·mol-1. Synchronous fluorescence spectral research shows Cy may affect the fluorescence emission of Trp residues of BSA. Furthermore, molecular docking is utilized to model the complex and probe the plausible quenching mechanism. It can be noted that the hydrogen bindings and hydrophobic interactions between Cy and BSA change the micro-environment of Trp213, which leads to the fluorescence quenching of BSA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 765 (2016)
Particle Size and Number Density Online Analysis for Particle Suspension with Polarization-Differentiation Elastic Light Scattering Spectroscopy
CHEN Wei-kang, and FANG Hui
The basic principle of polarization-differentiation elastic light scattering spectroscopy based techniques is that under the linear polarized light incidence, the singlely scattered light from the superficial biological tissue and diffusively scattered light from the deep tissue can be separated according to the differThe basic principle of polarization-differentiation elastic light scattering spectroscopy based techniques is that under the linear polarized light incidence, the singlely scattered light from the superficial biological tissue and diffusively scattered light from the deep tissue can be separated according to the difference of polarization characteristics. The novel point of the paper is to apply this method to the detection of particle suspension and, to realize the simultaneous measurement of its particle size and number density in its natural status. We design and build a coaxial cage optical system, and measure the backscatter signal at a specified angle from a polystyrene microsphere suspension. By controlling the polarization direction of incident light with a linear polarizer and adjusting the polarization direction of collected light with another linear polarizer, we obtain the parallel polarized elastic light scattering spectrum and cross polarized elastic light scattering spectrum. The difference between the two is the differential polarized elastic light scattering spectrum which include only the single scattering information of the particles. We thus compare this spectrum to the Mie scattering calculation and extract the particle size. We then also analyze the cross polarized elastic light scattering spectrum by applying the particle size already extracted. The analysis is based on the approximate expressions taking account of light diffusing, from which we are able to obtain the number density of the particle suspension. We compare our experimental outcomes with the manufacturer-provided values and further analyze the influence of the particle diameter standard deviation on the number density extraction, by which we finally verify the experimental method. The potential applications of the method include the on-line particle quality monitoring for particle manufacture as well as the fat and protein density detection of milk products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 770 (2016)
Fast Detection of Camellia Sinensis Growth Process and Tea Quality Informations with Spectral Technology: A Review
PENG Ji-yu, SONG Xing-lin, LIU Fei, BAO Yi-dan, and HE Yong
The research achievements and trends of spectral technology in fast detection of Camellia sinensis growth process information and tea quality information were being reviewed. Spectral technology is a kind of fast, nondestructive, efficient detection technology, which mainly contains infrared spectroscopy, fluorescence The research achievements and trends of spectral technology in fast detection of Camellia sinensis growth process information and tea quality information were being reviewed. Spectral technology is a kind of fast, nondestructive, efficient detection technology, which mainly contains infrared spectroscopy, fluorescence spectroscopy, Raman spectroscopy and mass spectroscopy. The rapid detection of Camellia sinensis growth process information and tea quality is helpful to realize the informatization and automation of tea production and ensure the tea quality and safety. This paper provides a review on its applications containing the detection of tea (Camellia sinensis) growing status(nitrogen, chlorophyll, diseases and insect pest), the discrimination of tea varieties, the grade discrimination of tea, the detection of tea internal quality (catechins, total polyphenols, caffeine, amino acid, pesticide residual and so on) , the quality evaluation of tea beverage and tea by-product, the machinery of tea quality determination and discrimination. This paper briefly introduces the trends of the technology of the determination of tea growth process information, sensor and industrial application. In conclusion, spectral technology showed high potential to detect Camellia sinensis growth process information, to predict tea internal quality and to classify tea varieties and grades. Suitable chemometrics and preprocessing methods is helpful to improve the performance of the model and get rid of redundancy, which provides the possibility to develop the portable machinery. Future work is to develop the portable machinery and on-line detection system is recommended to improve the further application. The application and research achievement of spectral technology concerning about tea were outlined in this paper for the first time, which contained Camellia sinensis growth, tea production, the quality and safety of tea and by-produce and so on, as well as some problems to be solved and its future applicability in modern tea industrial..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 775 (2016)
Study on Ammonia Emission Rules in a Dairy Feedlot Based on Laser Spectroscopy Detection Method
HE Ying, ZHANG Yu-jun, YOU Kun, WANG Li-ming, GAO Yan-wei, XU Jin-feng, GAO Zhi-ling, and MA Wen-qi
It needs on-line monitoring of ammonia concentration on dairy feedlot to disclose ammonia emissions characteristics accurately for reducing ammonia emissions and improving the ecological environment. The on-line monitoring system for ammonia concentration has been designed based on Tunable Diode Laser Absorption SpectrIt needs on-line monitoring of ammonia concentration on dairy feedlot to disclose ammonia emissions characteristics accurately for reducing ammonia emissions and improving the ecological environment. The on-line monitoring system for ammonia concentration has been designed based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology combining with long open-path technology, then the study has been carried out with inverse dispersion technique and the system. The ammonia concentration in-situ has been detected and ammonia emission rules have been analyzed on a dairy feedlot in Baoding in autumn and winter of 2013. The monitoring indicated that the peak of ammonia concentration was 6.11×10-6 in autumn, and that was 6.56×10-6 in winter. The concentration results show that the variation of ammonia concentration had an obvious diurnal periodicity, and the general characteristic of diurnal variation was that the concentration was low in the daytime and was high at night. The ammonia emissions characteristic was obtained with inverse dispersion model that the peak of ammonia emissions velocity appeared at noon. The emission velocity was from 1.48 kg/head/hr to 130.6 kg/head/hr in autumn, and it was from 0.004 5 kg/head/hr to 43.32 kg/head/hr in winter which was lower than that in autumn. The results demonstrated ammonia emissions had certain seasonal differences in dairy feedlot scale. In conclusion, the ammonia concentration was detected with optical technology, and the ammonia emissions results were acquired by inverse dispersion model analysis with large range, high sensitivity, quick response without gas sampling. Thus, it’s an effective method for ammonia emissions monitoring in dairy feedlot that provides technical support for scientific breeding..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 783 (2016)
Study on Kinetic of Hg2+ from Wastewater Absorbed by Lemon Residues
SHEN Wang-qing, WANG Miao, and YANG Ting
With low price and its superior adsorption performance after modification, currently agricultural waste is used as adsorbent of heavy metals in wastewater, which has become a hot research topic. To study on Hg2+ from wastewater absorbed by lemon residues that has been modified by 15% concentration of sulphuric acid. ThWith low price and its superior adsorption performance after modification, currently agricultural waste is used as adsorbent of heavy metals in wastewater, which has become a hot research topic. To study on Hg2+ from wastewater absorbed by lemon residues that has been modified by 15% concentration of sulphuric acid. The pore volume, pore size and other properties of the adsorbent were test. The samples were characterized by differential thermal analysis, IR, electron microscopy and spectroscopy. The result showed that the adsorption rate was controlled by membrane diffusion kinetics that was viewed as the first order kinetics equation of the Lagergren, which was physically absorbed. The adsorption properties of modified lemon residues were improved greatly, and the pore size distribution mainly was medium. There were three losses-weight process. There was a endothermic peak around 66 ℃ and two exotherm near 316 ℃ and 494 ℃. Basic framework of Lemon residues was not changed and structure of Lemon residues was amorphous; the surface of modified lemon residues loosen and many pores formed, and Hg2+ have been adsorbed effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 788 (2016)
Study on the Visualization of the Biomass of Chlorella sp. , Isochrysis galbana, and Spirulina sp. Based on Hyperspectral Imaging Technique
JIANG Lu-lu, WEI Xuan, ZHAO Yan-ru, SHAO Yong-ni, QIU Zheng-jun, and HE Yong
Effective cultivation of the microalgae is the key issue for microalgal bio-energy utilization. In nutrient rich culture conditions, the microalge have a fast growth rate, but they are more susceptible to environmental pollution and influence. So to monitor the the growth process of microalgae is significant during culEffective cultivation of the microalgae is the key issue for microalgal bio-energy utilization. In nutrient rich culture conditions, the microalge have a fast growth rate, but they are more susceptible to environmental pollution and influence. So to monitor the the growth process of microalgae is significant during cultivating. Hyperspectral imaging has the advantages of both spectra and image analysis. The spectra contain abundant material quality signal and the image contains abundant spatial information of the material about the chemical distribution. It can achieve the rapid information acquisition and access a large amount of data. In this paper, the authors collected the hyperspectral images of forty-five samples of Chlorella sp., Isochrysis galbana, and Spirulina sp., respectively. The average spectra of the region of interest (ROI) were extracted. After applying successive projection algorithm (SPA), the authors established the multiple linear regression (MLR) model with the spectra and corresponding biomass of 30 samples, 15 samples were used as the prediction set. For Chlorella sp., Isochrysis galbana, and Spirulina sp., the correlation coefficient of prediction (rpre) are 0.950, 0.969 and 0.961, the root mean square error of prediction (RMSEP) for 0.010 2, 0.010 7 and 0.007 1, respectively. Finally, the authors used the MLR model to predict biomass for each pixel in the images of prediction set; images displayed in different colors for visualization based on pseudo-color images with the help of a Matlab program. The results show that using hyperspectral imaging technique to predict the biomass of Chlorella sp. and Spirulina sp. were better, but for the Isochrysis galbana visualization needs to be further improved. This research set the basis for rapidly detecting the growth of microalgae and using the microalgae as the bio-energy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 795 (2016)
Hyperspectral Estimation of Apple Tree Canopy LAI Based on SVM and RF Regression
HAN Zhao-ying, ZHU Xi-cun, FANG Xian-yi, WANG Zhuo-yuan, WANG Ling, ZHAO Geng-xing, and JIANG Yuan-mao
Leaf area index（LAI) is the dynamic index of crop population size. Hyperspectral technology can be used to estimate apple canopy LAI rapidly and nondestructively. It can be provide a reference for monitoring the tree growing and yield estimation. The Red Fuji apple trees of full bearing fruit are the researching objectLeaf area index（LAI) is the dynamic index of crop population size. Hyperspectral technology can be used to estimate apple canopy LAI rapidly and nondestructively. It can be provide a reference for monitoring the tree growing and yield estimation. The Red Fuji apple trees of full bearing fruit are the researching objects. Ninety apple trees canopies spectral reflectance and LAI values were measured by the ASD Fieldspec3 spectrometer and LAI-2200 in thirty orchards in constant two years in Qixia research area of Shandong Province. The optimal vegetation indices were selected by the method of correlation analysis of the original spectral reflectance and vegetation indices. The models of predicting the LAI were built with the multivariate regression analysis method of support vector machine (SVM) and random forest (RF). The new vegetation indices, GNDVI527, NDVI676, RVI682, FD-NVI656 and GRVI517 and the previous two main vegetation indices, NDVI670 and NDVI705, are in accordance with LAI. In the RF regression model, the calibration set decision coefficient C-R2 of 0.920 and validation set decision coefficient V-R2 of 0.889 are higher than the SVM regression model by 0.045 and 0.033 respectively. The root mean square error of calibration set C-RMSE of 0.249, the root mean square error validation set V-RMSE of 0.236 are lower than that of the SVM regression model by 0.054 and 0.058 respectively. Relative analysis of calibrating error C-RPD and relative analysis of validation set V-RPD reached 3.363 and 2.520, 0.598 and 0.262, respectively, which were higher than the SVM regression model. The measured and predicted the scatterplot trend line slope of the calibration set and validation set C-S and V-S are close to 1. The estimation result of RF regression model is better than that of the SVM. RF regression model can be used to estimate the LAI of red Fuji apple trees in full fruit period..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 800 (2016)
Study on the Rapid Evaluation of Total Volatile Basic Nitrogen (TVB-N) of Mutton by Hyperspectral Imaging Technique
ZHU Rong-guang, YAO Xue-dong, DUAN Hong-wei, MA Ben-xue, and TANG Ming-xiang
Total Volatile Basic Nitrogen (TVB-N) was usually taken as the physicochemical reference value to evaluate the mutton freshness. In order to explore the feasibility of hyperspectral (HSI) imaging technique to detect mutton freshness, 71 representative mutton samples were collected and scanned using a diffuse reflectancTotal Volatile Basic Nitrogen (TVB-N) was usually taken as the physicochemical reference value to evaluate the mutton freshness. In order to explore the feasibility of hyperspectral (HSI) imaging technique to detect mutton freshness, 71 representative mutton samples were collected and scanned using a diffuse reflectance hyperspectral imaging (HSI) system in the Visible-Near infrared (NIR) spectral region (400～1 000 nm), and the chemical values of TVB-N content were determined using the semimicro Kjeldahl method according to the modified Chinese national standard. The representative spectra of mutton samples were extracted and obtained after selection of the region of interests (ROIs). The samples of calibration set and prediction set were divided at the ratio of 3∶1 according to the content gradient method. Optimum HSI calibration models of the mutton (TVB-N) were established and evaluated by comparing different spectral preprocessing methods and modeling methods, which included Stepwise Multiple Linear Regression (SMLR), Partial Least Squares Regression (PLSR) and Principal Component Regression (PCR) methods. The results are that through the utilization of Multiplicative Scatter Correction (MSC), first derivative, Savitzky-Golay (S-G) smoothing and mean-centering together, both PLSR and PCR were able to achieve quantitative detection of mutton TVB-N. As for the PLSR model of mutton TVB-N established, the spectral pretreatment methods chosen included MSC, first derivative, S-G (15,2) smoothing and mean-centering, and the latent variables (LVs) number used was 11. As for the calibration set of PLSR model of mutton TVB-N, the correlation coefficient (r) and root mean square error of calibration (RMSEC) were 0.92 and 3.00 mg·(100 g)-1, respectively. As for the prediction set of PLSR model of mutton TVB-N, the correlation coefficient (r), Root Mean Square Error of Prediction (RMSEP), and ratio of standard deviation to standard error of prediction (RPD) were 0.92, 3.46 mg·(100 g)-1 and 2.35, respectively. The study demonstrated that the rapid and accurate analysis of TVB-N, the key freshness attribute, could be implemented by using the hyperspectral imaging (HSI) technique. The study provides the basis for further rapid and non-destructive detection of other mutton freshness attributes by using the hyperspectral imaging (HSI) technique, the improvement of current modeling effect of TVB-N content and the application involved of the technique in the practical production..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 806 (2016)
On-Orbit Multispectral Sensor Characterization Based on Spectral Tarps
LI Xin, ZHANG Li-ming, CHEN Hong-yao, and XU Wei-wei
The multispectral remote sensing technology has been a primary means in the research of biomass monitoring, climate change, disaster prediction and etc. The spectral sensitivity is essential in the quantitative analysis of remote sensing data. When the sensor is running in the space, it will be influenced by cosmic radThe multispectral remote sensing technology has been a primary means in the research of biomass monitoring, climate change, disaster prediction and etc. The spectral sensitivity is essential in the quantitative analysis of remote sensing data. When the sensor is running in the space, it will be influenced by cosmic radiation, severe change of temperature, chemical molecular contamination, cosmic dust and etc. As a result, the spectral sensitivity will degrade by time, which has great implication on the accuracy and consistency of the physical measurements. This paper presents a characterization method of the degradation based on man-made spectral targets. Firstly, a degradation model is established in the paper. Then, combined with equivalent reflectance of spectral targets measured and inverted from image, the degradation characterization can be achieved. The simulation and on orbit experiment results showed that, using the proposed method, the change of center wavelength and band width can be monotored. The method proposed in the paper has great significance for improving the accuracy of long time series remote sensing data product and comprehensive utilization level of multi sensor data products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 811 (2016)
Research on Temporal and Spatial Evolution of Reheating Double-Pulse Laser-Induced Plasma
WANG Jing-ge, FU Hong-bo, NI Zhi-bo, HE Wen-gan, CHEN Xing-long, and DONG Feng-zhong
In order to investigate the emission enhancement mechanisms of reheating Double Pulse Laser-Induced Breakdown Spectroscopy (DP-LIBS), single pulse LIBS (SP-LIBS) and reheating DP-LIBS were carried out on an alloy steel sample respectively. The plasma emission was collected by an Echelle spectrometer with high resolutioIn order to investigate the emission enhancement mechanisms of reheating Double Pulse Laser-Induced Breakdown Spectroscopy (DP-LIBS), single pulse LIBS (SP-LIBS) and reheating DP-LIBS were carried out on an alloy steel sample respectively. The plasma emission was collected by an Echelle spectrometer with high resolution, while the plasma structure was monitored via fast-photography. The temporal and spatial evolutio ns of the plasma generated by SP-LIBS and reheating DP-LIBS were being studied. It is found that the plasma temperature in reheating DP-LIBS was higher than that of SP-LIBS, and there was a turning point for the decay rate of plasma temperature in reheating DP-LIBS when the delay time was equal to the inter-pulse time of DP-LIBS. Moreover, the inte nsity of the plasma image was increased by reheating DP-LIBS, and the height and width of the central region of the plasma were increased about 23.5% and 15.1% respectively. The results of spatial distribution showed that the inte nsity of Fe Ⅱ and N I lines in the plasma were obviously enhanced by reheating DP-LIBS when the distance from the sample surface was larger than 0.6 mm. While the inte nsity enhancement for Fe Ⅰ lines were little, even in some positio ns the inte nsity of Fe Ⅰ lines decreased. The plasma temperature of double-pulse configuration was about 2 000 K higher than that of SP-LIBS, and a larger hot region in the plasma was generated. It is evidenced that the emission enhancement mechanisms in reheating DP-LIBS is that the second laser pulse re-excited the plasma induced by the first laser pulse, and the higher plasma temperature resulted from the re-exciting process..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 817 (2016)
Study on the Emission Spectrum of Hydrogen Production with Microwave Discharge Plasma in Ethanol Solution
SUN Bing, WANG Bo, ZHU Xiao-mei, YAN Zhi-yu, LIU Yong-jun, and LIU Hui
Hydrogen is regarded as a kind of clean energy with high caloricity and non-pollution, which has been studied by many experts and scholars home and abroad. Microwave discharge plasma shows light future in the area of hydrogen production from ethanol solution, providing a new way to produce hydrogen. In order to furtherHydrogen is regarded as a kind of clean energy with high caloricity and non-pollution, which has been studied by many experts and scholars home and abroad. Microwave discharge plasma shows light future in the area of hydrogen production from ethanol solution, providing a new way to produce hydrogen. In order to further improve the technology and analyze the mechanism of hydrogen production with microwave discharge in liquid, emission spectrum of hydrogen production by microwave discharge plasma in ethanol solution was being studied. In this paper, plasma was generated on the top of electrode by 2.45 GHz microwave, and the spectral characteristics of hydrogen production from ethanol by microwave discharge in liquid were being studied using emission spectrometer. The results showed that a large number of H, O, OH, CH, C2 and other active particles could be produced in the process of hydrogen production from ethanol by microwave discharge in liquid. The emission spectrum intensity of OH, H, O radicals generated from ethanol is far more than that generated from pure water. Bond of O—H split by more high-energy particles from water molecule was more difficult than that from ethanol molecule, so in the process of hydrogen production by microwave discharge plasma in ethanol solution; the main source of hydrogen was the dehydrogenation and restructuring of ethanol molecules instead of water decomposition. Under the definite external pressure and temperature, the emission spectrum intensity of OH, H, O radicals increased with the increase of microwave power markedly, but the emission spectrum intensity of CH, C2 active particles had the tendency to decrease with the increase of microwave power. It indicated that the number of high energy electrons and active particles high energy electron energy increased as the increase of microwave power, so more CH, C2 active particles were split more thoroughly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 823 (2016)
Study on Soil Elements Detection with Laser-Induced Breakdown Spectroscopy: A Review
YU Ke-qiang, ZHAO Yan-ru, LIU Fei, PENG Ji-yu, and HE Yong
Laser-induced breakdown spectroscopy (LIBS), as a kind of atomic emission spectroscopy, has been considered to be a future new tool for chemical analysis due to its unique features, such as no need of sample preparation, stand-off or remote analysis. What’s more it can achieve fast and multi-element analysis.Therefore,Laser-induced breakdown spectroscopy (LIBS), as a kind of atomic emission spectroscopy, has been considered to be a future new tool for chemical analysis due to its unique features, such as no need of sample preparation, stand-off or remote analysis. What’s more it can achieve fast and multi-element analysis.Therefore, LIBS technology is regarded as a future “SurperStar” in the field of chemical analysis and green analytical techniques. At present, rapid and accurate detection and prevention of soil contamination (mainly in pollutants of heavy metals and organic matter) is deemed to be a concerned and serious central issue in modern agriculture and agricultural sustainable development. In this paper, the reseach achievements and trends of soil elements detection based on LIBS technology were being reviewed. The structural composition and foundmental of LIBS system is first briefly introduced. And the paper offers a review of on LIBS applications and fruitsincluding the detection and analysis of major element, nutrient element and heavy metal element. Simultaneously, some studies on soil related metials and fields are briefly stated. The research tendency and developing prospects of LIBS in soil detection are presented at last..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 827 (2016)
Study on the Identification of Geographical Indication Wuchang Rice Based on the Content of Inorganic Elements
LI Yong-le, ZHENG Yan-jie, TANG Lu, SU Zhi-yi, and XIONG Cen
Wuchang rice is a geographical indication product in China. Due to its high quality and low production, the phenomenon of fake is more and more serious. An effective identification method of Wuchang rice is urgent needed, for the maintenance of its brand image and interest of consumers. Base on the content of inorganicWuchang rice is a geographical indication product in China. Due to its high quality and low production, the phenomenon of fake is more and more serious. An effective identification method of Wuchang rice is urgent needed, for the maintenance of its brand image and interest of consumers. Base on the content of inorganic elements which are analyzed by ICP-AES and ICP-MS in rice, the identification model of Wuchang rice is studied combining with principal component analysis (PCA), Fisher discrimination and artificial neural network (ANN) in this paper. The effect on the identification of samples is poor through PCA, while the samples from Wuchang area and other areas can be identified accurately through Fisher discrimination and ANN. The average accurate identification ratio of training and verification set through Fisher discrimination is 93.5%, while the average accurate identification ratio through ANN is 96.4%. The ability to identify of ANN is better than Fisher discrimination. Wuchang rice can be identified accurately through the result of this research which provides a technology for the protection of geographical indications of this product..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 834 (2016)
Influence of the Experiment Energy Dispersive X-Ray Fluorescence Measurement of Uranium by Different Excitation Source
XIONG Chao, GE Liang-quan, LIU Duan, ZHANG Qing-xian, GU Yi, LUO Yao-yao, and ZHAO Jian-kun
Aiming at the self-excitation effect on the interference of measurements which exist in the process of Energy dispersive X-ray fluorescence method for uranium measurement. To solve the problem of radioactive isotopes only used as excitation source in determination of uranium. Utilizing the micro X-ray tube to test SelfAiming at the self-excitation effect on the interference of measurements which exist in the process of Energy dispersive X-ray fluorescence method for uranium measurement. To solve the problem of radioactive isotopes only used as excitation source in determination of uranium. Utilizing the micro X-ray tube to test Self-excitation effect to get a comparison of the results obtained by three different uranium ore samples—109Cd, 241Am and Mirco X-ray tube. The results showed that self-excitation effect produced the area measure of characteristic X-ray peak is less than 1% of active condition, also the interference of measurements can be negligible. Photoelectric effect cross-section excited by 109Cd is higher, corresponding fluorescence yield is higher than excited by 241Am as well due to characteristics X-ray energy of 109Cd, 22.11 & 24.95 KeV adjacent to absorption edge energy of Lα, 21.75 KeV, based on the above, excitation efficiency by 109Cd is higher than 241Am; The fact that measurement error excited by 241Am is significantly greater than by 109Cd is mainly due to peak region overlap between L energy peaks of uranium and Scattering peak of 241Am, 26.35 keV, These factors above caused the background of measured Spectrum higher; The error between the uranium content in ore samples which the X-ray tube as the excitation source and the chemical analysis results is within 10%. Conclusion: This paper come to the conclusion that the technical quality of uranium measurement used X-ray tube as excitation source is superior to that in radioactive source excitation mode..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 838 (2016)
Based on Curing Age of Calcined Coal Gangue Fine Aggregate Mortar of X-Ray Diffraction and Scanning Electron Microscopy Analysis
DONG Zuo-chao, XIA Jun-wu, DUAN Xiao-mu, and CAO Ji-chang
By using X-ray diffraction (XRD) and environmental scanning electron microscope (SEM) analysis method, we studied the activity of coal gangue fine aggregate under different calcination temperature. In view of the activity of the highest 700 ℃ high temperature calcined coal gangue fine aggregate mortar of hydration prodBy using X-ray diffraction (XRD) and environmental scanning electron microscope (SEM) analysis method, we studied the activity of coal gangue fine aggregate under different calcination temperature. In view of the activity of the highest 700 ℃ high temperature calcined coal gangue fine aggregate mortar of hydration products, microstructure and strength were discussed in this paper, and the change laws of mortar strength with curing age (3, 7, 14, 28, 60 and 90 d) growth were analyzed. Test results showed that coal gangue fine aggregate with the increase of calcination temperature, the active gradually increases. When the calcination temperature reaches 700 ℃, the activity of coal gangue fine aggregate is the highest. When calcining temperature continues to rise, activity falls. After 700 ℃ high temperature calcined coal gangue fine aggregate has obvious ash activity, the active components of SiO2 and Al2O3 can be with cement hydration products in a certain degree of secondary hydration reaction. Through on the top of the activity of different curing age 700 ℃ high temperature calcined coal gangue fine aggregate mortar, XRD and SEM analysis showed that with the increase of curing age, secondary hydration reaction will be more fully, and the amount of hydration products also gradually increases. Compared with the early ages of the cement mortar, the products are more stable hydration products filling in mortar microscopic pore, which can further improve the microstructure of mortar, strengthen the interface performance of the mortar. The mortar internal structure is more uniform, calcined coal gangue fine aggregate and cement mortar are more of a strong continuous whole, which increase the later strength of hardened cement mortar, 700 ℃ high temperature calcined coal gangue fine aggregate pozzolanic effect is obvious..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 842 (2016)
Research on an Equal Wavelength Spectrum Reconstruction Method of Interference Imaging Spectrometer
XIE Pei-yue, YANG Jian-feng, XUE Bin, L Juan, HE Ying-hong, LI Ting, and MA Xiao-long
Interference imaging spectrometer is one of the most important equipments of Chang’E 1 satellite, which is applied to analysis the material composition and its distribution of the surface on the moon. At present, the spectral resolution of level 2B scientific data obtained by existing methods is 325 cm-1. If we use theInterference imaging spectrometer is one of the most important equipments of Chang’E 1 satellite, which is applied to analysis the material composition and its distribution of the surface on the moon. At present, the spectral resolution of level 2B scientific data obtained by existing methods is 325 cm-1. If we use the description way of wavelength resolution, various spectrum is different: the first band is 7.6 nm, the last band is 29 nm, which introduces two questions: (1) the spectral resolution description way mismatch with the way of ground spectral library used for calibration and comparison; (2) The signal-to-noise ratio of the spectra in the shortwave band is low due to the signal entering narrow band is little. This paper discussed the relationship between wavelength resolution and cut-off function based on the reconstruction model of CE-1 interference imaging spectrometer. It proposed an adjustable cut-off function changing with wavelength or wavelength resolution, while selected the appropriate Sinc function as apodization to realize the reconstruction of arbitrary specified wavelength resolution in the band coverage. Then we used this method to CE-1 on orbit 0B data to get a spectral image of 29 nm wavelength resolution. Finally, by usingthe signal-to-noise ratio, principal component analysis and unsupervised classification method on the reconstruction results with 2 grade science data from ground application system for comparison, the results showed that: signal-to-noise ratio of the shortwave band increased about 4 times, and the average increased about 2.4 times, the classification based on the spectrum was consistent, and the quality of the data was greatly improved. So, EWSR method has the advantages that: (1) in the case of keeping spectral information steadiness, it can improve the signal-to-noise ratio of shortwave band spectrum though sacrificed part of spectral resolution; (2) it can achieve the spectral data reconstruction which can set arbitrary band position or specify any wavelength resolution within the band range..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 848 (2016)
The Research on Optic Fiber FBG Corrosion Sensor Based on the Analysis of the Spectral Characteristics
ZHANG Jun, ZENG Jie, WANG Bo, WANG Wen-juan, LIANG Da-kai, and LIU Xiao-ying
Aiming at meeting the need of aluminum corrosion monitoring in aerospace field, a pre-load type fiber grating corrosion sensor based on an aluminum thin tube structure is proposed. The corrosion sensor of aluminum alloy structure in-service monitoring mechanism is studied, a theoretical model about the relation of FBG Aiming at meeting the need of aluminum corrosion monitoring in aerospace field, a pre-load type fiber grating corrosion sensor based on an aluminum thin tube structure is proposed. The corrosion sensor of aluminum alloy structure in-service monitoring mechanism is studied, a theoretical model about the relation of FBG reflection spectral chasacteristics and aluminum thickness variation is also obtained. Optical fiber grating corrosion monitoring test system based on the capillary structure of aluminum alloy is constructed by acid-base environment. The problem of cross sensitivity of temperature and strain is solved. by configuring an optical fiber grating which is not affected by strain and only sensitive to temperature inside the aluminum alloy tube. The results shows that he aluminum tube packaging design not only can sense the effects of corrosion on the mechanical properties, but also can interference shielding effect of corrosion on the tube optical fiber sensing device. With the deepening of the metal tube corrosion and aluminum alloy tube thickness gradually thinning, fiber grating reflective spectrum gradually shift to the short wavelength and the wall thickness and the grating center wavelength offset has a good monotonic relation. These characteristics can provide useful help to further research corrosion online monitoring based on optic fiber sensor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 853 (2016)
Study on the Effects and Compensation Effect of Recording Parameters Error on Imaging Performance of Holographic Grating in On-Line Spectral Diagnose
JIANG Yan-xiu, Bayanheshig, YANG Shuo, ZHAO Xu-long, WU Na, and LI Wen-hao
To making the high resolution grating, a numerical calculation was used to analyze the effect of recording parameters on groove density, focal curve and imaging performance of the grating and their compensation. Based on Fermat’s principle, light path function and aberration, the effect on imaging performance of the grTo making the high resolution grating, a numerical calculation was used to analyze the effect of recording parameters on groove density, focal curve and imaging performance of the grating and their compensation. Based on Fermat’s principle, light path function and aberration, the effect on imaging performance of the grating was analyzed. In the case of fixed using parameters, the error of the recording angle has a greater influence on imaging performance, therefore the gain of the weight of recording angle can improve the accuracy of the recording angle values in the optimization; recording distance has little influence on imaging performance; the relative errors of recording parameters cause the change of imaging performance of the grating; the results indicate that recording parameter errors can be compensated by adjusting its corresponding parameter. The study can give theoretical guidance to the fabrication for high resolution varied-line-space plane holographic grating in on-line spectral diagnostic and reduce the alignment difficulty by analyze the main error effect the imaging performance and propose the compensation method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 857 (2016)
Research on Multi-Spectral Target Recognition System Based on the Magneto-Optical Modulation
YAN Xiao-yan, QIN Jian-min, and QIAO Ji-pin
The technology of target recognition based on characteristic multi-spectrum has many advantages, such as strong detection capability and discriminating capability of target species. But there are some problems, it requires that you obtain the background spectrum as a priori knowledge, and it requires that the change ofThe technology of target recognition based on characteristic multi-spectrum has many advantages, such as strong detection capability and discriminating capability of target species. But there are some problems, it requires that you obtain the background spectrum as a priori knowledge, and it requires that the change of background spectrum is small with time. Thereby its application of real-time object recognition is limited in the new environment, or the complex environment. Based on magneto-optical modulation and characteristic multi-spectrum the method is designed, and the target is identified without prior access to the background spectrum. In order to achieve the function of the target information in the one acquisition time for tested, compared to conventional methods in terms of target detection, it’s adaptability is better than before on the battlefield, and it is of more practical significance. Meanwhile, the magneto-optical modulator is used to suppress the interference of stray light background, thereby improving the probability of target recognition. Since the magneto-optical modulation provides incremental iterative target spectral information, therefore, even if the unknown background spectrum or background spectrum change is large, it can significantly improve the recognition accuracy of information through an iterative target spectrum. Different test targets back shimmering light intensity and background intensity values were analyzed during experiments, results showed that three targets for linearly polarized reflectance modulation is significantly stronger than the background. And it was of great influence to visible imaging target identification when measured target used camouflage color, but the system of polarization modulation type can still recognize target well. On this basis, the target range within 0.5 km×2 km multi-wavelength characteristics of the target species were identified. When using three characteristic wavelengths, the probability of target identification significantly reduced at around 2km, when using four or five characteristic wavelength position, the probability of target identification reach up to more than 95.0%. Meanwhile, in order to reduce the calculation and improve the real-time detection capability of the system, finally, four characteristic wavelengths was selected. So the system has a certain application value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 864 (2016)
Analyzer Design of Atmospheric Particulate Matter’s Concentration and Elemental Composition Based on β and X-Ray’s Analysis Techniques
GE Liang-quan, LIU He-fan, ZENG Guo-qiang, ZHANG Qing-xian, REN Mao-qiang, LI Dan, GU Yi, LUO Yao-yao, and ZHAO Jian-kun
Monitoring atmospheric particulate matter requires real-time analysis, such as particulate matter’s concentrations, their element types and contents. An analyzer which is based on β and X rays analysis techniques is designed to meet those demands. Applying β-ray attenuation law and energy dispersive X-ray fluorescence Monitoring atmospheric particulate matter requires real-time analysis, such as particulate matter’s concentrations, their element types and contents. An analyzer which is based on β and X rays analysis techniques is designed to meet those demands. Applying β-ray attenuation law and energy dispersive X-ray fluorescence analysis principle, the paper introduces the analyzer’s overall design scheme, structure, FPGA circuit hardware and software for the analyzer. And the analyzer can measure atmospheric particulate matters' concentration, elements and their contents by on-line analysis. Pure elemental particle standard samples were prepared by deposition, and those standard samples were used to set the calibration for the analyzer in this paper. The analyzer can monitor atmospheric particulate matter's concentration, 30 kinds of elements and content, such as TSP, PM10 and PM2.5. Comparing the measurement results from the analyzer to Chengdu Environmental Protection Agency’s monitoring results for monitoring particulate matters, a high consistency is obtained by the application in eastern suburbs of Chengdu. Meanwhile, the analyzer are highly sensitive in monitoring particulate matters which contained heavy metal elements (such as As, Hg, Cd, Cr, Pb and so on). The analyzer has lots of characteristics through technical performance testing, such as continuous measurement, low detection limit, quick analysis, easy to use and so on. In conclusion, the analyzer can meet the demands for analyzing atmospheric particulate matter’s concentration, elements and their contents in urban environmental monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 868 (2016)
Study on Strain Detection with Si Based on Bicyclic Cascade Optical Microring Resonator
TANG Jun, LEI Long-hai, ZHANG Wei, ZHANG Tian-en, XUE Chen-yang, ZHANG Wen-dong, and LIU Jun
Optical micro-ring resonator prepared on Silicon-On-Insulator (SOI) has high sensitivity, small size and low mode volume. Its high sensitivity has been widely applied to the optical information transmission and inertial navigation devices field, while it is rarely applied in the testing of Mechanics. This paper presentOptical micro-ring resonator prepared on Silicon-On-Insulator (SOI) has high sensitivity, small size and low mode volume. Its high sensitivity has been widely applied to the optical information transmission and inertial navigation devices field, while it is rarely applied in the testing of Mechanics. This paper presents a cantilever stress/strain gauge with an optical micro-ring resonator. It is proposed the using of radius change of ring waveguide for the sensing element. When external stress is put on the structure, the radius of the SOI ring waveguide will be subjected to variation, which causes the optical resonant parameters to change. This ultimately leads to a red-shift of resonant spectrum, and shows the excellent characteristics of the structure’s stress/strain sensitivity. Designed a bicyclic cascade embedded optical micro-cavity structure, which was prepared by employing MEMS lithography and ICP etching process. The characteristic of stress/strain sensitivity was calculated theoretically. Two values of 0.185 pm·kPa-1 and 18.04 pm·microstrain-1 were obtained experimentally, which also was verified by theoretical simulations. Comparing with the single-loop micro-cavity structure, its measuring range and stress sensitivity increased by nearly 50.3%, 10.6%, respectively. This paper provides a new method to develop micro-opto-electromechanical system (MOEMS) sensors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 874 (2016)
Vibrational Spectroscopic Study of N-［4-［1-Hydroxy-2-［(1-Methyl Ethyl) Amino］ Ethyl］ Phenyl］ Methane Sulfonamide
N. Balamurugan, S. Sampathkrishnan, and C. Charanya
The vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 4 000～400 and 4 000～400 cm-1 respectively, for N-［4-［1-hydroxy-2-［(1-methyl ethyl) amino］ ethyl］ phenyl］ methane sulfonamide (HPAEPMS) molecule. Theoretical calculations were performed by ab initio Density FunctionalThe vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 4 000～400 and 4 000～400 cm-1 respectively, for N-［4-［1-hydroxy-2-［(1-methyl ethyl) amino］ ethyl］ phenyl］ methane sulfonamide (HPAEPMS) molecule. Theoretical calculations were performed by ab initio Density Functional Theory (DFT) method using 6-31G(d,p) basis set. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 880 (2016)
A Relative Humidity Pulse Approach to Observe Mass Transfer Processes Controlled by Bulk and Surface for Aerosols
ZHANG Yun, PANG Shu-feng, and ZHANG Yun-hong
With combination of a pulse relative humidity (RH) controlling system and rapid scan vacuum FTIR technique, dynamic hygroscopicity of aerosol can be studied during pulse RH process. The time-resolved FTIR spectra can provide both water content of aerosols and water vapor amount of the aerosol ambient in sub-second timeWith combination of a pulse relative humidity (RH) controlling system and rapid scan vacuum FTIR technique, dynamic hygroscopicity of aerosol can be studied during pulse RH process. The time-resolved FTIR spectra can provide both water content of aerosols and water vapor amount of the aerosol ambient in sub-second time resolution. Experiments were performed on sodium nitrate, magnesium sulfate and magnesium nitrate aerosols. By comparing their hygroscopicity in pulse RH process and quasi-equilibrium state, for sodium nitrate aerosols, under time resolution of 0.12 s, we didn’t see water transfer delay between aerosols and ambient environment. For magnesium sulfate aerosols, after gel formation, the water transfer speed is limited by the aerosol bulk phase. While for aged magnesium nitrate aerosols, non-soluble species generated and formed a film on the surface of aerosol particles, which slow down the water exchange rate between aerosols and ambient environment. This method turned out to be an efficient and convenient tool to elucidate the water transfer process controlled by bulk and surface for aerosols..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 887 (2016)
The Fluorescent Properties of Dissolved Organic Matter and Assessment of Total Nitrogen in Overlying Water with Different Dissolved Oxygen Conditions
ZHANG Hua, WANG Kuan, SONG Jian, ZHANG Yong, HUANG Ming, HUANG Jian, ZHU Jing, HUANG Shan, and WANG Meng
This paper used excitation-emission matrix spectroscopy (EEMs) to probe the fluorescence properties of dissolved organic matter (DOM) in the overlying water with different dissolved oxygen (DO) conditions, investigating the relationship between protein-like fluorescence intensity and total nitrogen concentration. The rThis paper used excitation-emission matrix spectroscopy (EEMs) to probe the fluorescence properties of dissolved organic matter (DOM) in the overlying water with different dissolved oxygen (DO) conditions, investigating the relationship between protein-like fluorescence intensity and total nitrogen concentration. The resulting fluorescence spectra revealed three protein-like components (high-excitation wavelength tyrosine, low-excitation wavelength tyrosine, low-excitation wavelength tryptophan) and two fulvic-like components (ultraviolet fulvic-like components, visible fulvic-like components) in the overlying water. Moreover, the protein-like components were dominant in the overlying water’s DOM. The fluorescence intensity of the protein-like components decreased significantly after aeration. Two of the protein-like components—the low-excitation wavelength tyrosine and the low-excitation wavelength tryptophan—were more susceptible to degradation by microorganisms within the degradable organic matter with respect to the high-excitation wavelength tyrosine. In contrast, the ultraviolet and visible fulvic-like fluorescence intensity increased along with increasing DO concentration, indicating that the fulvic-like components were part of the refractory organics. The fluorescence indices of the DOM in the overlying water were between 1.65~1.80, suggesting that the sources of the DOM were related to terrigenous sediments and microbial metabolic processes, with the primary source being the contribution from microbial metabolism. The fluorescence indices increased along with DO growth, which showed that microbial biomass and microbial activity gradually increased with increasing DO while microbial metabolism also improved, which also increased the biogenic components in the overlying water. The fluorescence intensity of the high-excitation wavelength tyrosine peak A showed a good linear relationship with the total nitrogen concentration at higher DO concentrations of 2.5, 3.5, and 5.5 mg·L-1, with r2 being 0.956, 0.946, and 0.953, respectively. This study demonstrated that excitation-emission matrix spectroscopy can distinguish the transformation characteristics of the DOM and identify the linear relationship between the fluorescence intensity of the high-excitation wavelength tyrosine peak A and total nitrogen concentration, thus providing a quick and effective technique and theoretical support for river water monitoring and water restoration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 890 (2016)
Spectral Analysis of Interaction between Human Telomeric G-Quadruplex and Liliflorin A, the First Lignan Derivative Interacted with G-Quadruplex DNA
LIU Ting-ting, ZHOU Shuang, JIA Qian-lan, WANG Wen-shu, YAN Xiao-qian, ZHANG Wen-hao, WANG Shuai-qi, and JIAO Yu-guo
Human telomeric G-quadruplex is a four-stranded structure folded by guanines (G) via Hoogsteen hydrogen bonding. The ligands which stabilize the G-quadruplex are often telomerase inhibitors and may become antitumor agents. Here, the interaction between a lignan derivative liliflorin A and human telomeric sequence dGGG(Human telomeric G-quadruplex is a four-stranded structure folded by guanines (G) via Hoogsteen hydrogen bonding. The ligands which stabilize the G-quadruplex are often telomerase inhibitors and may become antitumor agents. Here, the interaction between a lignan derivative liliflorin A and human telomeric sequence dGGG(TTAGGG)3G-quadruplex HTG21 were examined by CD, FRET, and NMR spectroscopic methods. In addition, Molecular Docking was used to study the binding of liliflorin A to dTAGGG(TTAGGG)3G-quadruplex HTG23. The CD data showed that liliflorin A enhanced HTG21 Tm. The Tm value of G-quadruplex was enhanced 3.2 ℃ by 4.0 μmol·L-1 liliflorin A in FRET. The NMR spectra of HTG21 showed vivid alteration after reacting with liliflorin A in 3 hours. Molecular Docking suggested liliflorin A bound to the wide groove of HTG23 at G9, G10, G16 and G17. Liliflorin A was the first lignan derivative that could stabilize HTG21 selectively and provided a new candidate for antitumor drug design targeting on human telomeric G-quadruplex..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 896 (2016)
Study on the Comparisons of the Establishment of Two Mathematical Modeling Methods for Soil Organic Matter Content Based on Spectral Reflectance
ZHANG Pei, and LI Yi
Existing prediction models of soil organic matter content (SOC) are restricted by some factors, such as sampling scale, soil type and spectral parameters of samples. Therefore, it is necessary to make a comparative analysis on larger scales to build a quantitative model with better feasibility and greater accuracy. A tExisting prediction models of soil organic matter content (SOC) are restricted by some factors, such as sampling scale, soil type and spectral parameters of samples. Therefore, it is necessary to make a comparative analysis on larger scales to build a quantitative model with better feasibility and greater accuracy. A total of 225 soil samples were collected in an extensive region of the upper reaches of Heihe river basin. SOC and spectral reflectance were being measured. All the samples were divided into 2 subsets-a modeling subset (180 samples) and a validation subset (45 samples). Six indices were obtained through transformation of soil spectral reflectance (R), continuum-removal (CR), reciprocal (REC), logarithm of reciprocal (LR), first-order differential (FDR) and Kubelka-Munck transformation coefficient (K-M). To build the mathematical model of SOC with 12 spectral indices, two methods, i.e., stepwise linear regression and partial least-square regression were used based on the modeling subset, respectively; the validation subset is used for model evaluation. The results indicated that: (1) Regardless of different modeling methods, model between SOC and LR index was always the best among the 6 reflectance-related indices. LR was the best index for predicting SOC; (2) For the model based on the LR index, the accuracy of model using partial least-square regression method was better than that using stepwise linear regression method; (3)225 samples were compared to verify the former available published SOC model. Both the predicted and measured values passed the mean value t-test, and the Pearson correlation coefficient reached 0.826. It shows that local prediction model can be applied to the research of predicting SOC in the larger scale..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 903 (2016)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 3, 1 (2016)
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