Journals >Spectroscopy and Spectral Analysis
Contents
2018
Volume: 38 Issue 3
55 Article(s)
Export citation format
Study of Plant Growth Regulators Detection Technology Based on Terahertz Spectroscopy
CHEN Xi-ai, WU Xue, ZHANG Song, and WANG Ling
The terahertz spectra of gibberellin, forchlorfenuron and thidiazuron in the range of 0.2 to 2.0 THz were obtained by THz time-domain spectroscopy, based on which their absorption and refraction spectra were calculated. The results showed that all of them had obvious characteristic absorption peaks in the terahertz banThe terahertz spectra of gibberellin, forchlorfenuron and thidiazuron in the range of 0.2 to 2.0 THz were obtained by THz time-domain spectroscopy, based on which their absorption and refraction spectra were calculated. The results showed that all of them had obvious characteristic absorption peaks in the terahertz band. The terahertz absorption spectra of nineteen different substances were classified and tested by least squares support vector machine. Particle swarm optimization and genetic algorithm were applied for the parameter optimization of the least squares support vector machine, and the stability of the model was tested with noise addition. This study demonstrates the feasibility of terahertz spectroscopy for identification of plant growth regulators and will provide a new approach for the detection of plant growth regulators..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 665 (2018)
Calibration Method of Broadband Cavity Enhanced Absorption Spectroscopy for Measuring Atmospheric NO2
LING Liu-yi, WEI Ying, HUANG You-rui, HU Ren-zhi, and XIE Pin-hua
Accurate calibration of the spectrometer based on incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) is very essential for quantitative measurements of trace gases in the atmosphere. An incoherent broadband cavity enhanced absorption spectrometer using a blue light emitting diode as light source is Accurate calibration of the spectrometer based on incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) is very essential for quantitative measurements of trace gases in the atmosphere. An incoherent broadband cavity enhanced absorption spectrometer using a blue light emitting diode as light source is developed for quantitative detection of atmospheric NO2. This paper describes three methods for calibrating the mirror reflectivity of the spectrometer in the spectral region of 430～490 nm, which are: (1) only using known absorption of standard NO2; (2) using known absorptions of standard NO2 and oxygen collisional pair in pure oxygen; (3) using Rayleigh extinction coefficient of pure nitrogen and helium. The wavelengths corresponding to maximum reflectivity calibrated with these methods are all about 460 nm, whereas different maximum reflectivity and respectively 0.999 25, 0.999 33 and 0.999 37. NO2 samples with various mixing ratios are measured with the IBBCEAS spectrometer in order to compare these three methods. Disagrees of about 14% and 19% between method (1) and other two methods are respectively found, whereas only about 4% disagree between method (2) and (3). The measuring results show that the concentration uncertainty of NO2 sample and inner wall loss maybe deteriorate the calibration accuracy of method (1) and hence this approach is not recommended. High sensitivity and calibration methods of the IBBCEAS spectrometer are further demonstrated by simultaneously measuring the absorption of atmospheric NO2 and oxygen collisional pair in the atmosphere in the spectral region of 440～485 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 670 (2018)
Theoretical and Experimental Study on Radiation Characteristics of Nanofluids
HUANG Zi-qiang, BAI Jian-bo, LU Xiao, CHEN Bing-yan, LUO Peng, LI Hua-feng, and ZHANG Chao
With the rapid development of modern society, energy shortage and environmental pollution are becoming increasingly serious. Nowadays, investigations on new energy and new energy technology are commonly listed as a primary energy strategy worldwide. As a clean energy, solar energy is enormous in amount and the utilizatWith the rapid development of modern society, energy shortage and environmental pollution are becoming increasingly serious. Nowadays, investigations on new energy and new energy technology are commonly listed as a primary energy strategy worldwide. As a clean energy, solar energy is enormous in amount and the utilization of solar energy and related technology has attracted widespread concern around the world. Photovoltaic and photovoltaic heat technology can be coupled with nanofluid-based solar direct absorption thermal collector, which is an important means to improve the efficiency of comprehensive utilization of solar energy. Because nanofluids radiation theory play an important role in the development of new photovoltaic-thermal experimental platform and study on radiation characteristics of nanofluids is still in the initial stage, it is of great significance for the study of the law and mechanism of nanofluids radiation. In this paper, firstly, recent researches of nanofluid radiation characteristics were reviewed. The radiation characteristics of nanofluids were investigated theoretically and then the Rayleigh scattering model and the Mie model were used to analyze the critical radiation characteristics—transmittances of the nanofluids. Furthermore, the consistency between different theoretical models and experimental datum was studied by contrast verification between experiments and theory calculation. The conclusions showed that Mie model performed better than Rayleigh scattering model and express a better applicability in the development of photovoltaic thermal experimental platform. The purpose of this paper was using nanoparticles to change the radiation characteristics of the fluid while exploring a simple and efficient calculation criterion of the nanofluid radiation characteristics in practical design. Besides, the principle of the volume fraction which is one of the important factors for nanofluid radiation characteristics was obtained. Consequently, solar energy utilization rate of nanofluid-based solar direct absorption thermal collector would be improved. This theoretical study on radiation characteristics of nanofluids was expected to prompt on the application of nanotechnology in the field of solar energy and improve the efficiency of comprehensive utilization of solar energy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 676 (2018)
Design and Research for a Kind of Optical Fiber Sensor Based on Extroradinary Optical Tramsimission Phenomenon
YUAN Ting-ting, HUANG Peng, LI Han-yang, SHANG Yan-ting, YANG Xing-hua, ZHANG Yang, LI Han-yang, and ZHAO En-ming
Optical sensors with extraordinary optical transmission phenomenon have proved to hold great potential in the field of chemical and biomedical due to its significant near-field enhancement and high sensitivity to the dielectric environment. However, the utility of this kind of optical fiber sensors is largely limited bOptical sensors with extraordinary optical transmission phenomenon have proved to hold great potential in the field of chemical and biomedical due to its significant near-field enhancement and high sensitivity to the dielectric environment. However, the utility of this kind of optical fiber sensors is largely limited by its complex nanofabrication methods and expensive instruments. Here to relieve these restrictions, a method of transferring templates was used to process periodic metal nanostructures onto endface of optical fibers. And an experimental setup was built to study sensing characteristics and sensing mechanism of the optical fiber sensors. The obtained results indicated high quality periodic metal nanostructures can be transferred onto endface of optical fibers by the template transfer method. The sensitivity of the resulting sensor to refractive index change was 594.45 nm·RIU-1 (refractive index unit) and figure of merit (FOM) achieved 33.12..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 681 (2018)
Numerical Study on OH* Radicals in the Laminar Methane/Oxygen Co-Flowing Jet Diffusion Flame
HE Lei, GONG Yan, GUO Qing-hua, HU Chong-he, and YU Guang-suo
OH* is one of the major excited radicals in flame. The chemiluminescence information is generally applied in combustion diagnostics to indicate the flame structure, strain rate, equivalence ratio, heat release rate, etc. In this paper, the numerical study on OH* radicals was conducted in the laminar methane/oxygen co-fOH* is one of the major excited radicals in flame. The chemiluminescence information is generally applied in combustion diagnostics to indicate the flame structure, strain rate, equivalence ratio, heat release rate, etc. In this paper, the numerical study on OH* radicals was conducted in the laminar methane/oxygen co-flowing jet diffusion flames. The detailed GRI 3.0 mechanism combined with OH* radicals reaction mechanism was used in the numerical model. Based on the two-dimensional OH* distributions, the pathways of OH* formation in different area were analyzed. The effects of oxygen-fuel equivalence ratio and coaxial nozzle structure on OH* intensity and distribution were also discussed. The simulation results were consistent with the experiment results, indicating that the numerical model can effectively describe the two-dimensional OH* distributions. The results show that there are two different types of OH* distribution areas, and the OH* radicals in these two areas are formed respectively through the reactions CH+O2=OH*+CO and H+O+M=OH*+M. The flame structure can be indicated according to the distribution area of OH* radicals. With increasing the oxygen-fuel equivalence ratio, the distribution area of OH* radicals gradually expands to the downstream of flame. The distinctions of OH* distribution can be used to characterize the combustion condition. If OH* radicals only distribute over the upstream of the flame and appear discrete in shape, the flame is under the oxygen-deficient combustion. If OH* radicals distribution appears as a ring shape, the flame is under the oxygen-enriched combustion. Under the same oxygen flow rate, the size of annular channel has a significant impact on the mole fraction of OH*. Reducing the size of annular channel can enhance the mixture of fuel and oxygen as well as improve the radiation intensity of the OH* chemiluminescence, which makes the flame diagnosis more convenient..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 685 (2018)
Analysis of UTA Spectra of Nd∶YAG Pulse Laser Produced Mo Plasmas
WU Tao, HE Jun, WANG Shi-fang, and TANG Chao-hong
The high purity molybdenum (Mo) sample were irradiated with the Nd∶YAG pulse laser to generate plasmas in a vacuum chamber. The time integrated emission spectroscopy of laser produced Mo plasmas was measured in the spectral range of 2~9 nm using different laser power density. Based on collision-radiative model (CRM) anThe high purity molybdenum (Mo) sample were irradiated with the Nd∶YAG pulse laser to generate plasmas in a vacuum chamber. The time integrated emission spectroscopy of laser produced Mo plasmas was measured in the spectral range of 2~9 nm using different laser power density. Based on collision-radiative model (CRM) and unresolved transition arrays (UTA) data of highly charged Mo ions calculated with Cowan code, the theoretical synthetic spectra at different electron temperature and electron density were obtained assuming individual spectral line obeyed Gaussian broadening. Fair agreements between simulated and experimental spectra have been achieved. Experimental and theoretical spectra show that the UTAs of 3d—4f transitions in Mo ⅩⅥ-ⅩⅫ ions have several peaks lying in water window region. By controlling the laser pulse parameters and optimizing the plasmas confinement conditions, it is expected to obtain high ion fraction of highly charged Mo ions irradiating photons in water window wavelength region, showing the potential for water window living cell microscopic imaging sources in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 692 (2018)
Study on TDLAS System with a Miniature Multi-Pass Cavity for CO2 Measurements
LI Meng, GUO Jin-jia, YE Wang-quan, LI Nan, ZHANG Zhi-hao, and ZHENG Rong-er
The measurement of CO2 at air-sea interface is significant to marine scientific research. There are many commercial instruments can be used for CO2 measurements in marine environment, among which the instruments based on tunable diode laser absorption spectroscopy (TDLAS) play an important role due to the advantages ofThe measurement of CO2 at air-sea interface is significant to marine scientific research. There are many commercial instruments can be used for CO2 measurements in marine environment, among which the instruments based on tunable diode laser absorption spectroscopy (TDLAS) play an important role due to the advantages of high sensitivity, good environmental adaptability, etc. As a core component of a TDLAS system, the volume and optical path of a multi-pass cavity limit the size and sensitivity of the system. For the application of underwater dissolved CO2 measurements, due to the samll quantity of degassing gas and high sensitivity, both the small size and long optical path are required for a multi-pass cavity. In this work, a miniature multi-pass cavity was designed for the potential underwater dissolved CO2 measurements. The miniature multi-pass cavity composed of two identical spherical mirrors (D=25.4 mm, f=50 mm)separated at a distance of 38 mm, realized 253 reflection times, providing an effective optical path length of 10 m and an inner volume of 90 mL. Based on the miniature multi-pass cavity, a direct absorption TDLAS system was developed for CO2 measurement. The system was evaluated with a series of different concentrations of CO2 standard gases. The obtained limit of detection (LOD) was about 26×10-6 (volume ratio), and the response was good linear with R2=99.986% over the whole range. A commercial ultraportable greenhouse gas analyzer (UGGA) from Los Gatos Research (LGR) was also used for comparison measurements, and the results showed a consistent trend with R2 of more than 97% under conditions of both high fluctuation at daytime and low changes at nighttime in laboratory. The experiments testified the performance of the developed TDLAS system for CO2 measurements, which means that the improved system will be used in field experiments in the near future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 697 (2018)
Inversion Research on the Spectrum Emissivity Based on Slowing Varying Properties of Emissivity
YANG Yi-fan, CAI Hong-xing, WANG Zhao-xuan, LI Yan, and LI Shuang
Emissivity is an important parameter of radiation thermometry. Based on Planck’s law, in the temperature measurement by radiation , there is an underdetermined problem, N equation containing N+1 unknown number, a new calculation method is put forward with the application of the emissivity of slowly varying characteristEmissivity is an important parameter of radiation thermometry. Based on Planck’s law, in the temperature measurement by radiation , there is an underdetermined problem, N equation containing N+1 unknown number, a new calculation method is put forward with the application of the emissivity of slowly varying characteristics, in order to reduce the number of unknowns, simplify the calculation process, we conducted theoretical and experimental measures to verify the calculation method. The results showed that both theoretical thermal radiation spectrum and the experimental data of the inversion results of emissivity spectrum and temperature were consistent with material emissivity and its real temperature. When T=1 173 K, the maximum difference of the inversion temperature is 13 K, and the maximum absolute error of the emissivity is 0.05,the greater the emissivity of slowly vary, the shorter the wavelength interval , the higher the accuracy of calculation is. Such method can be applied to obtain temperature and emissivity based on multi-spectral data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 702 (2018)
Effects of Different LED Light Qualities on the Growth of Trifoliate Orange Seedlings
LI Si-jing, YI Xiao-tong, LI You-fang, WANG Jun-xiu, LING Li-li, and PENG Liang-zhi
Chongqing, the only non-endemic area of Huanglong disease, has been established firstly virus-free three-stage breeding system for quality Citrus variety in China. However, that the annual sunshine hours in Chongqing are few and unevenly distributed during the year prolongs the growth period in Citrus seedlings compareChongqing, the only non-endemic area of Huanglong disease, has been established firstly virus-free three-stage breeding system for quality Citrus variety in China. However, that the annual sunshine hours in Chongqing are few and unevenly distributed during the year prolongs the growth period in Citrus seedlings compared to other’s Citrus plantation areas. Therefore, this seriously restricts the developing speed of citrus nursery industry in Chongqing. Recently, the light emitting diode (LED) has been used as supplementary lighting to cultivate Citrus during the autumn and winter that can shorten the growth period of citrus seedling and accelerate the virus-free breeding of new variety. In order to investigate the effects of different LED light qualities on their seedlings growth, trifoliate orange (Poncirus trifoliata L. Raf) in sand culture were selected as materials. 2-month-old seedlings were exposed to 150 μmol·m-2·s-1 irradiance for a 16 h·d-1 photoperiod under white fluorescent lamp (FL) and the following six LED light, respectively: red light (R), blue light(B), 1∶1 ratio of red/blue (RB 1∶1), 4∶1 ratio of red/blue (RB 4∶1), 4∶1∶1 ratio of red/yellow/blue (RYB 4∶1∶1), white light (W). Their phenotypic and biomass indices were measured. Results showed that roots of seedlings were significantly longer, stem diameters (excluding RB 1∶1) were wider and leaves were narrower under composite LED light treatments than those under fluorescent lamp treatement. Compared with fluorescent lamp treatment, stem elongation were inhibited, along with decrease in leaf numbers and increase leaf thickness under RB 1∶1 and RB 4∶1 treatments, under which leaf length and area were increased. Furthermore, stem elongation, leaf number and leaf length increased, while leaf area enlarged, and leaf thickness decreased under RYB 4∶1∶1 treatment in comparison with fluorescent lamp treatment. Dry matter accumulation and biomass distribution of shoot and root were better under white LED light and high ratio red LED light treatments than those under monochromatic light treatments, particularly with the greatest shoot biomass and the minimum root/shoot ratio under RYB 4∶1∶1 treatment. So, it is concluded that RYB 4∶1∶1 treatment is the best choice for the matter accumulation and shoot growth of trifoliate orange seedlings. This can offer the theoretical evidence for the accurate supplemental lighting system on the season or area of lack light, especially in Chongqing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 708 (2018)
Synthesis of 9,10-Diheterocyclicanthracenes and Performance Correlations in Triplet-Triplet Annihilation Upconversion
CHEN Jia, YE Chang-qing, ZHU Sai-jiang, WANG Xiao-mei, and TAO Xu-tang
Low-power photon upconversion (UC) can convert low-energy photons to high-energy photons based on triplet-triplet annihilation (TTA) mechanism, which invloves a bimolecular system containing a sensitizer and an emitter (acceptor) . Firstly, the sensitizer harvests the excitation energy toward its triplet excited state Low-power photon upconversion (UC) can convert low-energy photons to high-energy photons based on triplet-triplet annihilation (TTA) mechanism, which invloves a bimolecular system containing a sensitizer and an emitter (acceptor) . Firstly, the sensitizer harvests the excitation energy toward its triplet excited state with intersystem crossing (ISC), then the triplet energy of the sensitizer is transferred to the acceptor (i.e., triplet-triplet energy transfer, TTT). Lastly, two excited triplet acceptors would annihilate (i.e., triplet-triplet annihilation, TTA) while one of them irradiates the high-energy light (upconversion) from the excited state to the ground state. Since the processes mentioned above, including ISC, TTT and TTA, are transition-allowed, the TTA-UC can be achieved at ultra-low excitation power that is less than the terrestrial solar radiation (ca. 100 mW·cm-3), which shows wide spread practical applications such as in solar cells. Compared to the development of triplet sensitizers, little attention has been paid to the development of triplet acceptors. Here, two new compounds: 9,10-Di(3-furan)anthracence (DFA) and 9, 10-di(3-thiophene)anthracence (DTA) were synthesized as the triplet acceptor (emitter) that can doped with palladium(Ⅱ) tetraphenylporphyrin derivatives (PdTPPMe or PdTPPCOOH) to obtain the triplet sensitizer/acceptor bimolecular system. Under the low-power excitation of the diode laser (532 nm, 70 mW·cm-2), these bimolecular systems could emit strong green-to-blue upconversion with the efficiencies (ΦUC) in the order of DFA/PdTPPCOOH (10.11%)＞DTA/PdTPPCOOH (7.20%)＞DFA/PdTPPMe (6.31%)＞DFA/PdTPPMe (5.45%). The obtained results have shown that large triplet-triplet quenching constant (kQ), high prompt fluorescence quantum (Φf) and fast delayed fluorescence (τDF) are responsible for effective upconversion efficiency (ΦUC). Moreover, it was found that oxygen-containing 9, 10-di(3-furan)anthracence (DFA) and PdTPPCOOH within the mixed alcohol media can effectively interact each other based on the hydrogen bond (H-bond) and resulting larger triplet-triplet quenching constant (kQ), which have contribution to enhancement the upconversion efficiency. With the help of Pt/WO3 photo-catalyst, the conversion from coumarin to 7-hydroxycoumarin was successfully achieved under the irradiation of our green-to-blue upconversion produced with bimolecular DFA/PdTPPCOOH in alcohol media..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 715 (2018)
Spectral Investigation on the Direct-Current Uniform Discharge Ignited by a Dielectric Barrier Discharge at Atmospheric Pressure
LI Xue-chen, WU Kai-yue, JIA Peng-ying, BAO Wen-ting, and DI Cong
Atmosphere pressure uniform plasma has the broad application prospect in the industrial field. In order to get a atmosphere pressure uniform plasma in large scale, a large gap uniform discharge (up to 5 cm) was initiated between a needle anode and a plate cathode, which was ignited under a low sustaining voltage by a cAtmosphere pressure uniform plasma has the broad application prospect in the industrial field. In order to get a atmosphere pressure uniform plasma in large scale, a large gap uniform discharge (up to 5 cm) was initiated between a needle anode and a plate cathode, which was ignited under a low sustaining voltage by a coaxial dielectric barrier discharge in ambient air with argon used as working gas. The characteristics of the discharge were investigated. The coaxial dielectric barrier discharge can lower the voltage for gas breakdown effectively. The results showed that the atmospheric pressure uniform discharge included a plasma column near the anode, a plasma plume, a dark space and a cathode glow. The plasma column and the cathode glow were continuous discharges, while in the plasma plume region the discharges at different positions initiated at different time. In fact, the plasma plume behaved like a “plasma bullet” which traveled from the cathode to the plasma column. Through electrical method, the voltage-current characteristic was investigated. The voltage-current curve had a negative slope, whichwas similar with the normal glow discharge at low pressure. By analyzing the optical emission spectrum from the discharge, the optical emission spectrum was composed of the second positive system of nitrogen molecules, the spectral lines from argon atom and oxygen atom. By Boltzmann plot method, the spatially-resolved excited electron temperature was obtained. It was found that the excited electron temperature of the plasma column was lower than that of the plasma plume. These experimental phenomena were explained qualitatively. These results are of great importance to the development of atmospheric pressure uniform discharge plasma source and its application in industrial field..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 722 (2018)
Determination of Circulation Blood Volume by Modified Pulse Dye Densitometry
LIU Guang-da, SHANG Xiao-hu, WEI Xing, LIU Yang, LIU Song-yang, and ZHA Yu-tong
Circulating blood volume (CBV) is important for disease evaluation and operation monitoring of patients with cardiovascular and cerebrovascular diseases in clinical application as the main hemodynamic parameters. Indocyanine green (ICG) was used as a tracer in the pulse dye densitometry, and we detected CBV noninvasiveCirculating blood volume (CBV) is important for disease evaluation and operation monitoring of patients with cardiovascular and cerebrovascular diseases in clinical application as the main hemodynamic parameters. Indocyanine green (ICG) was used as a tracer in the pulse dye densitometry, and we detected CBV noninvasively in vivo by establishing the spectral curve of the diluted excreted ICG. In clinical application, the accuracy of CBV detected with pulse dye densitometry is lower than the expected value owing to the influences of blood oxygen fluctuation and background light. To solve the problem, this paper researched circulation blood volume detection by modified pulse dye densitometry. The specific process was as follows. We injected the ICG reagent into the vein in the elbow of patient, and collected the transmission spectrum signal and the background photoelectric signal respectively using the photoelectric sensor. Then we conducted differential operation on the collected data to eliminate the influences of blood oxygen fluctuation and background light and established an accurate ICG spectral curve. So CBV and other hemodynamic parameters could be calculated finally. The result of the comparative test among 131I isotope method, the “gold standard”, and the proposed method indicated that the modified pulse dye densitometry reduced the average relative error of CBV detection from 6.85% to 4.53%, which improved the detection accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 727 (2018)
The Distribution and Influencing Factors of Carbon Dioxide in the Surface Seawater of the South Yellow Sea during Spring
CHEN Fa-rong, ZHENG Xiao-ling, ZHENG Li, SUN Jun-qing, SUN Jie, HAN Li-hui, and WANG Xiao-ru
The partial pressure of carbon dioxide (pCO2) in the surface seawater of the South Yellow Sea(SYS) was investigated by means of cruising observation during the spring of 2007. The distribution characters and influencing factors of the pCO2 were studied by combining with the cogredient data of the seawater temperature, The partial pressure of carbon dioxide (pCO2) in the surface seawater of the South Yellow Sea(SYS) was investigated by means of cruising observation during the spring of 2007. The distribution characters and influencing factors of the pCO2 were studied by combining with the cogredient data of the seawater temperature, salinity, chlorophyll, pH. The results showed that the values of the pCO2 in the surface seawater of the SYS was in the range of 365.2~734.9 μatm, with an average of 548.0 μatm, the maximum value appeared in sea area near 121.5°E, 33.4°N, and the minimum value appeared in sea area near 123°E, 32.3°N. As a whole the distribution of the pCO2 present obvious horizontal inhomogeneity, gradually decreased from west to east, and was higher at the middle latitude than both sides under the combined influence of biological, hydrological and chemical factors. The pCO2 was in direct proportion to the seawater temperature and in inverse proportion to the seawater salinity in the shoal-water area along the northern coast of Jiangsu Province and the near shore area of southern Shandong Province, but there was a reverse trend at the mouth of Yangtze River. In addition, there was a negative correlation between the pCO2 and the chlorophyll as well as between the pCO2 and the pH value in the whole investigated sea area. In this study, it was the first time that one of two CO2 analyzers was calibrated by series-connecting one of the channels, meanwhile, the other analyzer was calibrated with the standard gas of carbon dioxide through the other channel. Therefore, the concentrations of carbon dioxide in air and seawater could be continuously monitored. It was proved that the method was simple to operate, and the data obtained were accurate and reliable, with the hope of providing technical support for capacity building on energy conservation and emission reduction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 732 (2018)
Research on the Chlorophyll Content (SPAD) Distribution Based on the Consumer-Grade Modified Near-Infrared Camera
ZHANG Jian, MENG Jin, ZHAO Bi-quan, ZHANG Dong-yan, and XIE Jing
Convenient and reliable crop nutrition diagnosis methods is basis of scientific crop fertilizer management and the core of the precision agriculture, and chlorophyll content is an important index of crop nitrogen nutrition content. In this research, the research object was rice leaf, and visible image and the center waConvenient and reliable crop nutrition diagnosis methods is basis of scientific crop fertilizer management and the core of the precision agriculture, and chlorophyll content is an important index of crop nitrogen nutrition content. In this research, the research object was rice leaf, and visible image and the center wavelength of 650, 680, 720, 760, 850 and 950 nm near infrared image were captured by transformed ordinary camera and filters. Then the relative reflectance values of different wave band were acquired. After regression analysis with visible-band and near-infrared band combined, the high precision and stable models were selected. Compared with the three imaging channels of camera, the correlation between chlorophyll content (SPAD value) and R channel was higher than B, G channels. Results showed that in the comparison of vegetation indexes, GVI can best reflect growth status of crops, and 760 nm has become the best near-infrared band in SPAD prediction. The model prediction accuracy R2 of the least squares support vector machine method combined with multiple vegetation index was 0.831 4, while ideal result had been achieved. Meanwhile, hyperspectral image of rice leaf was captured by hyperspectral imager. Compared the two imaging modalities, the multi factor prediction model based on vegetation index has the same precision. Experiments proved that consumer-grade near infrared camera could gain similar estimation result of chlorophyll content as hyperspectral imager..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 737 (2018)
Possibilistic Fuzzy K-Harmonic Means Clustering of Fourier Transform Infrared Spectra of Tea
WU Bin, WANG Da-zhi, WU Xiao-hong, and JIA Hong-wen
Different variety of tea often has diversified organic chemical components, and their effects are not the same. Therefore, it is very necessary to develop a simple, efficient, high recognition rate method in classifying tea varieties. Mid-infrared spectroscopy is a rapid detection technology, and there is noise signal Different variety of tea often has diversified organic chemical components, and their effects are not the same. Therefore, it is very necessary to develop a simple, efficient, high recognition rate method in classifying tea varieties. Mid-infrared spectroscopy is a rapid detection technology, and there is noise signal in the mid-infrared spectra of tea samples collected by spectrometer. With a view to identifying tea varieties through the classification of the mid-infrared spectra of tea samples with noise, possibilistic fuzzy c-means clustering was applied in K-harmonic means clustering (KHM) and a novel clustering, called possibilistic fuzzy K-harmonic means clustering (PFKHM), was proposed. PFKHM can produce both fuzzy membership value and typicality value and solved the noise sensitivity problem of KHM. First of all, we used FTIR-7600 spectrometer to scan three varieties of tea samples (i. e. Emeishan Maofeng, high quality Leshan trimeresurus and low quality Leshan trimeresurus) for their Fourier transform infrared spectroscopy (FTIR) data. The wave number of FTIR data ranged from 4 001.569 to 401.121 1 cm-1. Secondly, we employed principal component analysis (PCA) to compress spectral data into 20-dimensional data which were compressed into two-dimensional data by linear discriminant analysis (LDA). Lastly, we used KHM and PFKHM to classify the tea varieties respectively. The experimental results indicated that when the weight index m=2, q=2 and p=2 the clustering accuracy rates of KHM and PFKHM achieved 91.67% and 94.44%, respectively. KHM was convergent after 12 iterations and PFKHM was convergent after 12 iterations. Tea varieties could be quickly and accurately classified by testing tea with FTIR technology, compressing spectral data with PCA and LDA, and classifying tea varieties with PFKHM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 745 (2018)
Feasibility of Rapid Evaluation of Urea-Formaldehyde Fertilizer by Infrared Spectroscopy
LIU Xing-bin, WANG Yue, HAN Xiao-ri, and MA Bin
At present, the rapid evaluation methods of urea formaldehyde fertilizer (UFF) efficiency are based on the activity coefficient method of urea formaldehyde (UF) water solubility, but the specific operating rules and technical indexes are different in different countries and regions because of activity coefficient methoAt present, the rapid evaluation methods of urea formaldehyde fertilizer (UFF) efficiency are based on the activity coefficient method of urea formaldehyde (UF) water solubility, but the specific operating rules and technical indexes are different in different countries and regions because of activity coefficient method limitation. The nutrient release rate of UFF is directly related to the structure of UF, which is not directly related to its solubility in aqueous solution at different temperatures. Therefore, it is more reasonable to study the nutrient release from UF structure. In this study, we investigated the feasibility of fourier transform infrared spectroscopy (FTIR) to evaluate the structure of UF under different factors of water content, urea content and formaldehyde storage time, so as to find a new UFF evaluation method. We investigated the relationship between the infrared absorption spectra of the product under different reaction conditions, the amount of product produced and the nutrient release of the reaction product of different urea in the acidic environment. It can be seen from the research results that the spectrum can reflect the change of water and urea addition and the change of formaldehyde storage time on the relative strength of the absorption peak of the characteristic group of UF. Through these changes, the change of UF composition can be judged. These judgments can be confirmed from the amount of the product, and the results of the soil culture experiments were further confirmed by the infrared spectrum to determine the correctness. The above results showed that it was feasible to study the fine change of UF structure by infrared absorption spectroscopy. If the mathematical model was established between the fine changes of urea formaldehyde infrared spectrum and UF nutrient release in the soil, a new means to assessment UFF fertilizer efficiency would be provided accurately and rapidly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 750 (2018)
Classification of Broad Bean Pest of Visible-Near Infrared Spectroscopy Based on Cloud Computing
XIA Ji-an, YANG Yu-wang, CAO Hong-xin, HAN Chen, GE Dao-kuo, and ZHANG Wen-yu
Based on the visible-near infrared reflectance spectra of broad bean leaves, by combining the derivative spectra, we analyzed the spectral characteristics of experiment samples with three levels of pests: healthy leaf, leaf with a small amount of pests and leaf with many pests, and selected the optimum waveband for pesBased on the visible-near infrared reflectance spectra of broad bean leaves, by combining the derivative spectra, we analyzed the spectral characteristics of experiment samples with three levels of pests: healthy leaf, leaf with a small amount of pests and leaf with many pests, and selected the optimum waveband for pest detection. The Hadoop, Spark and VMWare virtual machines were used to build the cloud computing platform, and the MLlib machine learning library was used to realize the classification models of artificial neural network (ANN) and support vector machine (SVM). We also conducted classification modeling and prediction of the full waveband and optimum waveband spectra of broad bean leaves with three levels of pests. The experiment results showed that the ANN pest spectrum classification model had higher accuracy than the SVM pest spectrum classification model, and the ANN model also had higher operating efficiency on the cloud platform.In the meantime, the prediction accuracy for full-waveband spectrum was higher than that for optimum waveband. By expanding the spectrum datasets, the computational efficiency of clouding computing technology in spectrum data mining can be significantly improved. The classification detection based on cloud computing can provide new technique and method for the spectral recognition of crop biotic stress..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 756 (2018)
In Situ FTIR Study of CO Adsorption on Pt-Sn/Al2O3 Reforming Catalyst
HAO Hua-hua, YUAN Hui, XU Guang-tong, XIANG Yan-juan, and MA Ai-zeng
Catalytic reforming, which produces raw material of aromatic hydrocarbon and high-octane clean-gasolineblending component, is a principal technology. According to the content of platinum and tin loading on industrial reforming catalyst, platinum loading was kept constant at 0.6 Wt% and the amount of tin was varied fromCatalytic reforming, which produces raw material of aromatic hydrocarbon and high-octane clean-gasolineblending component, is a principal technology. According to the content of platinum and tin loading on industrial reforming catalyst, platinum loading was kept constant at 0.6 Wt% and the amount of tin was varied from 0 to 1 Wt% in the catalysts. A series of Pt-Sn/Al2O3 reforming catalysts were characterized with in situ FTIR of adsorbed CO method which is established in this study. And the adsorbed CO infrared peaks were obtained at room temperature on Sn/Al2O3 catalysts that the mount of tin was under 1 Wt% in the first time. At room temperature the CO species of Pt sites adsorbed on the surface of Pt-Sn/Al2O3 reforming catalysts mainly on linearly-bonded CO species. It was found that there was a general trend that the amount of bridge-bonded CO species was decreasing and the amount of linearly-bonded CO species was increasing, with increasing amounts of tin in the catalyst. It was stated that the dispersity of platinum atoms was increasing. The temperature increasing desorption process was used to show that the CO band of Pt sites disappeared completely at 300 ℃ on 0.6%Pt/Al2O3, and the CO band of Sn sites disappeared completely at 120 ℃ on 0.3%Sn/Al2O3. The CO band of Pt sites and Sn sites disappeared completely at 350 ℃ on 0.6%Pt-0.3%Sn/Al2O3. Compared reforming catalysts Pt-Sn/Al2O3 with Pt/Al2O3, the linearly adsorbed CO band of Pt sites shift to high frequencies. This suggests that the electronic density of Pt increased due to the loading of Sn. Therefore, in situ FTIR is an effective tool for characterization of low metal reforming catalysts, which provides important information of interactions between tin and platinum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 761 (2018)
A FeO/TFe Determination Method of BIF Based on the Visible and Near-Infrared Spectrum
MAO Ya-chun, WANG Dong, WANG Yue, and LIU Shan-jun
The FeO/TFe of iron ore is an important index to evaluate the industrial value of iron ore and classify the industrial type of ore. The conventional FeO/TFe measurements cost a lot of labor with low efficiency and long period, which are not benefit for the economical, reasonable and effective iron ore exploitation. FirThe FeO/TFe of iron ore is an important index to evaluate the industrial value of iron ore and classify the industrial type of ore. The conventional FeO/TFe measurements cost a lot of labor with low efficiency and long period, which are not benefit for the economical, reasonable and effective iron ore exploitation. Firstly, the visible and near-infrared spectrums of the BIF samples from Anqian mining area of Liaoning province were measured and the spectral features were analyzed. Then, three indexes of ration index (RI), difference index (DI) and normalized difference index (NDI) were put forward for analyzing the correlation relations between the indexes and FeO/TFe, and exploring the sensitive waveband. The experimental results showed that the sensitive waveband results of FeO/TFe from these three indexes are all located at 935 and 1 050 nm. All of these three correlation coefficients are larger than 0.9 at these two wavelength and the maximum value is 0.971 for the RI. Therefore, the inversion model for FeO/TFe according to RI results can be established and verified based on the laboratory report. The prediction error of FeO/TFe is 0.038 and the coefficient of determination (R2) is 0.964 5. The experimental results can provide a new economical and effective approach for determining the FeO/TFe of BIF and mine exploring via remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 765 (2018)
Study on the Characteristics and Mechanism of Visible and Near Infrared Reflectance Spectra of Soil Heavy Metals
CHENG Hang, WAN Yuan, CHEN Yi-yun, WAN Qi-jin, SHI Tie-zhu, SHEN Rui-li, GUO Kai, and HU Jia-meng
In this paper, the reflectance spectral features of chromium(CrCl3), copper chloride(CuCl2) and zinc chloride (ZnCl2) were measured by using visible and near-infrared reflectance spectroscopy (VNIRS). Thus, the spectra features integrating with the state of electrons arranged of heavy metal elements, and combined with In this paper, the reflectance spectral features of chromium(CrCl3), copper chloride(CuCl2) and zinc chloride (ZnCl2) were measured by using visible and near-infrared reflectance spectroscopy (VNIRS). Thus, the spectra features integrating with the state of electrons arranged of heavy metal elements, and combined with the Crystal Field Theory were used to analyze where and why the wavebands of spectral features occurred. With the soil samples collected from Daye City, CrCl3, CuCl2 and ZnCl2 were added to them with different concentrations, and measured their VNIRS to study the impacts of different concentrations of heavy metals on soil reflectance spectra. Besides, the spectral data were transformed via different spectra pre-processing methods to explore the linear correlations between heavy metal concentrations and the reflectance spectra of the soil samples, and to study on where and why the Pearson’s significantly correlated wavebands (p<0.05) appeared and its potential mechanism. The results showed that the reflectance spectra in the range of visible and shortwave near-infrared of heavy metal compounds are related to the whether the 3d orbits of heavy metal elements filled by electron or not. The reflectance spectra of soil samples have been affected by the heavy metal compounds which were added, and negative correlations were revealed between the reflectance spectra data and the heavy metal concentrations. The maximum of the negative values of Pearson correlation coefficient were -0.788, -0.880, -0.824, respectively. There were some changes with the linear correlation between the heavy metal concentrations and the reflectance spectra, and the information of Pearson’s significantly correlated wavebands (p<0.05) became richer and more obvious after the reflectance spectra being pre-processed. This research indicated that the VNIRS of heavy metals are closely related to their electronic structure; the high concentrations of heavy metals in soils could be detected by the VNIRS technique, which has great potential in predicting soil heavy metal contents with rapid and efficient, non-destructive and cost-effective. Based on the VNIRS characteristics of some heavy metals, this paper integrated with the Crystal Field Theory to provide a theoretical basis and experimental reference for qualitative and quantitative analysis of reflectance spectroscopy of soil heavy metals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 771 (2018)
A Comparative Study of Infrared Fingerprint on Extracts of Three Kinds of from Onchidium struma
SHI Yan-mei, GU Bing-ning, YAO Li-xiang, and SHEN He-ding
Aiming to establish a comprehensive and rapid method to discriminate Onchidium struma（O. struma） quality from different regions, this research has established it’s three extract fingerprints in absolute ethyl alcohol, chloroform and ethyl acetate adoptd the infrared spectrometry (IR), and the information of infrared spAiming to establish a comprehensive and rapid method to discriminate Onchidium struma（O. struma） quality from different regions, this research has established it’s three extract fingerprints in absolute ethyl alcohol, chloroform and ethyl acetate adoptd the infrared spectrometry (IR), and the information of infrared spectra of O. struma samples originated from 6 regions has been collected. Automatic baseline correction and automatic optimized smoothness of Nicolet 5700 infrared spectrometer intelligence system are applied to optimize the IR fingerprint. Combining with the OPUS software. The results showed that, the three extract fingerprints function as a evaluation index to discriminate O. struma from different regions or different quality. The characteristic absorption peaks of three extracts has been contrasted, reflecting that the IR fingerprint spectra of ethyl acetate extract can reflect more abundant chemical composition information. The three extracts have different level and angle for identification of O. struma. Dual-indexes sequential analysis comparison shows that infrared spectrum of chloroform extract can reflect different habitats and different process mode O. struma differences: It has shown ShangHai（SH）and NingDe（ND）, WenZhou（WZ）and XiaMen（XM）were the region closer samples with higher common peak ratio（≥63.4）and lower variant peak ratio（≤38.5）; Sample SH and YueNan（YN）,YanCheng（YC）and XiaMen（XM）from the farther regions, were significant disparity with lower common peak ratio（≤40.9％）and higher variant peak ratio（≥50.0％）; In addition, sample XM and YN from closer region but have different process mode, which resulted in much lower common peak ratio（38.1％）and much higher variant peak ratio（125.0％）, To sum up, the quality control of aquatic products is a major concern for both the health authorities and the public, considering that current commercially available O. struma are acquired in natural way, acquiring area and time leading to the vital difference of their quality. The method of chloroform extracts dual-index sequence analysis could be used exactly and conveniently in qualitative evaluation of different region samples, and clarified the similarity level among different areas, also applied the quality evaluation of O. struma..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 779 (2018)
Characterization of Mineral Matter in Coal Ashes with Infrared and Raman Spectroscopy
YIN Yan-shan, YIN Jie, ZHANG Wei, TIAN Hong, HU Zhang-mao, FENG Lei-hua, and CHEN Dong-lin
The analysis of mineral matter in coal ash is based on the analysis and characterization of mineral composition. Mineral matter in two high-silicon and high-aluminum coal ashes were well characterized and identified with Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and X-ray diffraction (XRD). ThThe analysis of mineral matter in coal ash is based on the analysis and characterization of mineral composition. Mineral matter in two high-silicon and high-aluminum coal ashes were well characterized and identified with Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and X-ray diffraction (XRD). The results from combined use of FTIR and Raman spectroscopy were then compared with those of XRD. Results of FTIR show the presence of the strongest band in the range of 1 100～1 000 cm-1, such as the bands for quartz (1 089 cm-1) and metakaolinite (1 042 cm-1), which are both assigned to Si—O stretching vibration. In contrast to original infrared spectra, the second derivative infrared spectra show the positions of overlapping adsorption bands, which are masked in the original infrared spectra. The analysis of the overlapping adsorption bands are useful for the determination of mineral composition and thus provides more detailed information on mineral matter. For the anhydrite in coal ashes, the three Raman bands (1 157, 1 126, and 674 cm-1) are obviously similar to the three corresponding FTIR bands (1 151, 1 120, and 678 cm-1), for they show the identical vibration mode and close peak position. Moreover, the anhydrite in coal ashes shows other different bands in its FTIR and Raman spectra. Therefore, FTIR and Raman spectroscopy techniques are complementary for the identification of mineral phases in coal ashes. Although the anatase content of both coal ashes is very low, the Raman band of anatase (144 cm-1) is far more intense than the band of quartz (461 cm-1) because of the significantly high polarizability of Ti—O. The results of XRD show that the mineral components in both ashes are primarily quartz, muscovite, hematite, anhydrite, and unknown amorphous mineral phase. In addition to these minerals, combined use of FTIR and Raman spectroscopy indicates the presence of metakaolinite, amorphous silica, feldspar, calcite, anatase, etc. The combination of FTIR and Raman spectroscopy can therefore provide more detailed mineral composition than XRD for qualitative analysis of mineral matter in coal ashes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 789 (2018)
Identification of Tetrastigma hemsleyanum from Different Places with FT-NIR Combined with Kernel Density Estimation Algorithm
LAI Tian-yue, CAI Feng-huang, PENG Xin, CHAI Qin-qin, LI Yu-rong, and WANG Wu
Tetrastigma hemsleyanum, a rare medicinal herbs in China, contains many kinds of curative effects. However, the content of active ingredients of T. hemsleyanum from different places is remarkablely different. So, it is necessary to discriminate this promising medicinal T. hemsleyanum from different places. In this workTetrastigma hemsleyanum, a rare medicinal herbs in China, contains many kinds of curative effects. However, the content of active ingredients of T. hemsleyanum from different places is remarkablely different. So, it is necessary to discriminate this promising medicinal T. hemsleyanum from different places. In this work, spectra of T. hemsleyanum collected from Zhejiang, Yunnan, Anhui, Guangxi and Hubei provinces were recorded with Fourier transform near infrared spectroscopy, ranging from 10 000 to 4 000 cm-1. And the identification algorithm was applied to effectively identify the T. hemsleyanum from the known origin and other new places because the spectral data of T. hemsleyanum is not sufficient. Hence, in this study, three improvements of kernel density estimation algorithm have been achieved to identify T. hemsleyanum: (1) estimate the probability density of the samples via the perspective of distance; (2) calculate the bandwidth parameters by training the credibility of samples; (3) propose a recognition method based on probability density function of training set samples to recognize unknown origin. The identifying accuracy of training set sample and prediction set by the algorithm were reached 100% and 97.8%, respectively. Additionally, the new places of T. hemsleyanum can be accurately identified used the algorithm. The results show that the improved algorithm based on kernel density estimation can effectively identify T. hemsleyanum, and recognize the unknown origin samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 794 (2018)
Study on Aqueous Extracts of Three Kinds of Radix Puerariae in Clinical by 2D-IR Correlation Spectroscopy
XU Bei-lei, SUN Su-qin, ZHANG Gui-jun, LI Wen-lan, WANG Rui, ZHANG Yan, JIN Zhe-xiong, and SONG Lin
Traditional Chinese medicine is a complicated chemical mixture system. It is helpful for quality control of traditional Chinese medicine to establish a fast and effective analysis method. There are three kinds of Radix Puerariae in clinical, which are Pueraria thomsonii Benth, Pueraria lobata (Willd. ) Ohwi and simmereTraditional Chinese medicine is a complicated chemical mixture system. It is helpful for quality control of traditional Chinese medicine to establish a fast and effective analysis method. There are three kinds of Radix Puerariae in clinical, which are Pueraria thomsonii Benth, Pueraria lobata (Willd. ) Ohwi and simmered Pueraria lobata (Willd.) Ohwi (processed Radix Puerariae). Furthermore, aqueous extract is an important method for Radix Puerariae in clinical application. Therefore, a macroscopic IR fingerprint method, conventional Fourier transform infrared spectroscopy (FTIR) combined with second derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2D-IR), was applied to quickly analyze aqueous extracts of three kinds of Radix Puerariae in this study. The results showed that aqueous extract of Pueraria thomsonii Benth was different from aqueous extracts of Pueraria lobata (Willd.) Ohwi and simmered Pueraria lobata (Willd.) Ohwi by FTIR and SD-IR. There were differences of Pueraria lobata (Willd.) Ohwi after simmered by 2D-IR analysis. There were distinctive differences of main auto-peaks and cross-peaks in position and intensity. In the range of 1 800~1 300 cm-1, the strongest auto-peak was at 1 556 cm-1, and the second one appeared at 1 561 cm-1 in 2D-IR spectra of aqueous extracts of Pueraria lobata (Willd.) Ohwi. However, the strongest auto-peak was at 1 563 cm-1, and the second one appeared at 1 572 cm-1 in 2D-IR spectra of aqueous extracts of simmered Pueraria lobata (Willd.) Ohwi. In addition, there were two obvious auto-peaks at 1 536 and 1 634 cm-1, whose intensities were equal in 2D-IR spectra of aqueous extracts of Pueraria lobata (Willd.) Ohwi. The relative intensities of auto-peaks at 1 448 and 1 518 cm-1 were different in the two 2D-IR spectra. The cross-peaks at (1 518, 1 561) cm-1 and (1 518, 1 563) cm-1 of aqueous extract of Pueraria lobata (Willd.) Ohwi were stronger than those in 2D-IR of aqueous extract of simmered Pueraria lobata (Willd.) Ohwi. Therefore, aqueous extracts of Pueraria lobata (Willd.) Ohwi and simmered Pueraria lobata (Willd.) Ohwi can be identified intuitively by auto-peaks and cross peaks in 2D-IR spectra, and the change laws of functional groups of them can be revealed. It can provide the basis for the fast quality control of Radix Puerariae decoction in the process of clinical prescription application. The method including FTIR, SD-IR and 2D-IR, is rapid and exact, and can provide the means to analyze the complicated chemical mixture systems step by step..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 800 (2018)
Application of Near Infrared Hyperspectral Imaging for Detection of Azodicarbonamidein Flour
WANG Xiao-bin, HUANG Wen-qian, WANG Qing-yan, LI Jiang-bo, WANG Chao-peng, and ZHAO Chun-jiang
Near infrared hyperspectral imaging technology not only can acquire the image information of the sample, but also contain the spectra information about each pixel. Due to the abundant information that the method provides, it has been applied to detect food safety. This study adopted near infrared hyperspectral technoloNear infrared hyperspectral imaging technology not only can acquire the image information of the sample, but also contain the spectra information about each pixel. Due to the abundant information that the method provides, it has been applied to detect food safety. This study adopted near infrared hyperspectral technology to detect azodicarbonamide in flour. Hyperspectral images of pure azodicarbonamide, pure flour, and azodicarbonamide-flour mixture samples with different concentrations of azodicarbonamide were collected, by comparing the average diffuse reflectance spectra of pure azodicarbonamide and pure flour, the four absorption bands with high difference were found at 1 574.38, 2 038.55, 2 166.88 and 2 269.91nm. Second derivative was used for each pixel in the mixture sample ROI. Azodicarbonamide pixels and flour pixels were detected by three spectral similarity analysis methods: spectral angle mapper, spectral correlation angle, and spectral correlation measure. The results showed that the average spectra after pretreatment cannot effectively detect azodicarbonamide in flour. Spectral similarity analysis of single pixel spectra can be used to classify azodicarbonamide pixels and flour pixels in mixture samples. The validation of the classification results showed the correct classification of azodicarbonamide pixels and flour pixels. This study could provide a method support for the detection of additives in flour based on near infrared hyperspectral imaging technology, and provide a reference for the detection of adulterants in food..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 805 (2018)
A Kinetic Model of Hardness in Storage Periods of Fresh Jujubes at Room Temperature Using Two Dimensional Correlation Spectroscopy
LIU Jiang-long, ZHANG Shu-juan, SUN Hai-xia, XUE Jian-xin, and ZHAO Xu-ting
In order to realize the real-time monitoring of hardness and predict the storage life of fresh jujubes in storage periods at room temperature, a kinetic model of hardness according to near-infrared (NIR) spectroscopy was established. The influence of integrated thickness on storage life of jujubes was explored using twIn order to realize the real-time monitoring of hardness and predict the storage life of fresh jujubes in storage periods at room temperature, a kinetic model of hardness according to near-infrared (NIR) spectroscopy was established. The influence of integrated thickness on storage life of jujubes was explored using two dimensional correlation spectroscopy technology and the sensitive bands influenced by integrated thickness of 904, 980, 1 072, 1 200, 1 630, 1 941 and 2 215 nm respectively. The average hardness of the jujube pulp per day during storage was analyzed and then a zero level reaction equation was fitted, which was A=0.549 8-0.009 6A0-0.023 2t. The result showed that the correlation coefficient of the zero level reaction was 0.991 3 and the standard error was 6.116×10-4. The content of main material changed during storage because of the complex physiological and chemical reaction in the fresh jujube fruits. And this is represented through spectral characteristics and hardness. Coupled the spectral information in the sensitive band and the hardness index of the storage period, a partial least squares (PLS) model of jujube flesh hardness was established. The prediction precision of the model was 0.942 7, and the root mean squared error of prediction (RMSEP) was 0.021 0. And then, a kinetic model of jujube’ flesh hardness according to near-infrared (NIR) spectroscopy (A=0.549 8-0.009 6(0.793 6+0.655 1X1-3.804 2X2+2.372 2X3-1.884 2X4+3.637 3X5-1.041 7X6-1.327 8X7)-0.023 2t) was established through multivariate regression analysis, in which the spectral reflectances of characteristic bands are independent variables and the hardness indexes of jujube fruits are dependent variables. The correlation coefficient of this model was 0.983 9 and standard error was 0.024 9. The linear relation between storage life and near-infrared(NIR) spectroscopy was found to be t=23.698 2-0.413 8(0.793 6+0.655 1X1-3.804 2X2+2.372 2X3-1.884 2X4+3.637 3X5-1.041 7X6-1.327 8X7)-43.103 4(0.793 6+0.655 1X1t-3.804 2X2t+2.372 2X3t-1.884 2X4t+3.637 3X5t-1.041 7X6t-1.327 8X7t). The study shows that the near-infrared (NIR) spectroscopy technology that combining kinetic model of hardness can realize rapidly nondestructive testing of jujube’ flesh hardness index and the prediction of the storage time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 813 (2018)
The Improved Method of Trace Content for Raman Measurement Accuracy
ZHAO Xiao-yu, ZHAI Zhe, TAN Feng, TONG Liang, TIAN Fang-ming, and LIU Chang
To improve the measurement accuracy for the Raman spectrum of micro-substance is one of the difficulties in Raman analysis technique, which is prominent when measuring the micro-substance in organism under the background of high fluorescence. According to the burst and dispersed characteristics to Raman spectrum peak, To improve the measurement accuracy for the Raman spectrum of micro-substance is one of the difficulties in Raman analysis technique, which is prominent when measuring the micro-substance in organism under the background of high fluorescence. According to the burst and dispersed characteristics to Raman spectrum peak, the fluorescence background and noise fitting function was given in this paper respectively. The location of Raman spectrum peak and interference signal filtering had been realized through monitoring A-type uncertain function in the overall fitting deviation. The spectrum section had been divided according to the spectrum peak’s location further, and the spectrum peak signal had been enhanced through weakening the non-spectrum peak signal within monotone interval. Compared to other fluorescent processing methods, this method could split the overlapped characteristic peak accurately, however, the height of the characteristic peak will not be lowered and more sensitive semi-spectrum peak index could be offered. The experiment indicates that while processing the skin Raman spectrum, such method could obtain the affiliation Raman spectra of the amide I-belt, ceramide and CO ester in helical conformation. What’s more, the measurement model with the content of water-soluble sugar (rice leaf) had been established with the data after being processed by such method, and it had been found that the precision is superior to that of the model established by using the processing data of wavelet decomposition, fitting of a polynomial and nonlinear least square method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 818 (2018)
Calibration Transfer of Surface-Enhanced Raman Spectroscopy Quantitative Prediction Model of Potassium Sorbate in Osmanthus Wine to Other Wine
YANG Yu, PENG Yan-kun, LI Yong-yu, FANG Xiao-qian, ZHAI Chen, WANG Wen-xiu, and ZHENG Xiao-chun
Based on a self-built Raman scanning system and the SERS substrate named SC silver sol which was prepared with sodium citrate reduction method, a quantitative prediction model of potassium sorbate in osmanthus wine was established. The 34 osmanthus wine samples were divided into calibration set and validation set, and Based on a self-built Raman scanning system and the SERS substrate named SC silver sol which was prepared with sodium citrate reduction method, a quantitative prediction model of potassium sorbate in osmanthus wine was established. The 34 osmanthus wine samples were divided into calibration set and validation set, and the potassium concentration prediction model was established by multiple linear regression method. The determination coefficient and the root mean square error of the calibration set were 0.978 9 and 0.070 3 g·kg-1 respectively, the determination coefficient and the root mean square error of the validation set were 0.934 and 0.165 7 g·kg-1 respectively. The quantitative prediction model of potassium sorbate in osmanthus wine as the main spectrum model and by using the DS algorithm and the PDS algorithm, discussed the model transfer method of potassium sorbateintwo different wines. The K/S algorithm was used to sort the Raman spectra of bayberry wine. The main spectrum correction matrix was composed of osmanthus wine samples which had the same concentration ascalibration matrix. 15 bayberry wine samples were prepared to verify the effect of the transfer model. The results of the DS algorithm showed that RP and RMSEP were 0.906 1 and 0.215 0 g·kg-1 respectively. The results of the PDS algorithm showed that RP and RMSEP were 0.905 5 and 0.225 g·kg-1 respectively. DS algorithm and PDS algorithm can be achieved with a small number of samples for effective model transfer, and the best samples of the two methods were 4 and 3 respectively. In addition, window width of 5 was the best choice of PDS algorithm. Prediction model of potassium sorbate in osmanthus wine was suitable for the quantitative prediction of potassium sorbate in red bayberry wine by DS algorithm or PDS algorithm. The DS algorithm and PDS algorithm can achieve the transfer of prediction model for potassium sorbate in different wines. Potassium sorbatein red bayberry wine can be predicted by the prediction model of osmanthus wine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 824 (2018)
Rapid Detection of Four Chemical Components Added Illegally in Slimming Health Food with TLC Situ Raman Spectroscopy
LI Xiang, TAN Li-li, LIU Ji-cheng, LI Li, and JIA Shou-shi
To establish a thin layer chromatography (TLC) combined with Raman spectroscopy method and detect four chemical components (theophylline, caffeine, nandrolone phenylpropionate, spironolactone) added illegally in the slimming health food. The doping ingredient and substrate were separated with TLC, viewed and located wiTo establish a thin layer chromatography (TLC) combined with Raman spectroscopy method and detect four chemical components (theophylline, caffeine, nandrolone phenylpropionate, spironolactone) added illegally in the slimming health food. The doping ingredient and substrate were separated with TLC, viewed and located with UV light (254 nm), the spot of the doping ingredient is concentrated on the TLC plate before detecting the Raman spectroscopy of the concentrated point directly with 780 nm laser source. The effects of different formulations of slimming health food were studied, the limit of detect (LOD) was validated, and the TLC Situ Raman Spectroscopy method was established initially for detecting four chemical components added in the slimming health food. The common substrate in the slimming health food had no interference with the detecting results of doping components. The LOD was 2~4 μg. Two out of nine kinds of health food were detected to be with caffeine. In this study, we established TLC and Raman spectroscopy for the first time which was used for quick identification of four kinds of illegal chemicals added in health food, such as theophylline, etc. The method is precise, sensitive, rapid and simple, which could provide a new reference for the technology research of rapid detection of the ingredients added illegally in health food..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 830 (2018)
Research on Ultraviolet Scattering Characteristics of Haze Particles
ZHAO Tai-fei, LENG Yu-xin, ZHAO Si-ting, and SONG Peng
Ultraviolet (UV) is scattered by atmospheric haze particles, the changes of scattering channel characteristics in atmosphere haze can reflect the physical properties of the particles. The scattering channel characteristics of UV in different haze particle form and concentrationwere analyzed based on wireless ultravioleUltraviolet (UV) is scattered by atmospheric haze particles, the changes of scattering channel characteristics in atmosphere haze can reflect the physical properties of the particles. The scattering channel characteristics of UV in different haze particle form and concentrationwere analyzed based on wireless ultraviolet single and multiple scattering channel model, Mie scattering and T-matrix theory. The effect of scattering angle on the scattering intensity was researched; finally the experiment of UV light was completed. After theoretical and simulation analysis, the path loss and intensity distribution of UV communication under different haze particle form were obtained. The results showed that under UV line-of-sight (LOS) communication method, the path loss increased with the increase of haze particle concentration, and the communication quality was worse than sunny days; In short distance non-line-of-sight (NLOS) communication mode, the path loss at high haze concentration was lower than low concentration. However, as the communication distance continued to increase, communication quality of high haze concentration decreased sharply and achieved optimal in low haze concentration finally. The communication distance at 200 m was better than sunny environment. When the communication distance was the same, the intensity distribution of ultraviolet scattering at three kinds of haze concentrations decreased with the increase of scattering angle. when the scattering angle increased and more than 90 degrees, the scattering intensity under the low haze concentration was the highest. The main reason was that although the scattering angle continued to increase, the effective scattering volume decreased, so the scattering intensity in low haze concentration is larger. Moreover, when the particle size was the same, the attenuation of spherical particles was larger than non-spherical particles. The experimental results were similar to the simulation results, which proved the correctness of the simulation results. And to some extent, it proves that non-spherical particles are more than spherical particles in the atmosphere..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 837 (2018)
Research on Denoising of UV-Vis Spectral Data for Water Quality Detection with Compressed Sensing Theory Based on Wavelet Transform
ZHAO Ming-fu, TANG Ping, TANG Bin, HE Peng, XU Yang-fei, DENG Si-xing, and SHI Sheng-hui
It is of great significance to improve the measurement stability and accuracy of water quality detection system with direct spectrum method. Direct spectroscopy on-line water quality detection systems typically use long-lived, preheated pulsed xenon lamps and industrial-grade spectral detection devices for complex inspIt is of great significance to improve the measurement stability and accuracy of water quality detection system with direct spectrum method. Direct spectroscopy on-line water quality detection systems typically use long-lived, preheated pulsed xenon lamps and industrial-grade spectral detection devices for complex inspection environments. Since the whole spectral detection system is affected by the light source, the optical path and the photoelectric conversion device, the measured spectral data contains a large amount of noise, a wavelet denoising algorithm based on compressed sensing is proposed, which is compared with the traditional wavelet threshold denoising method. In this paper, the denoising was performed on the UV-Vis spectra of the standard solution of potassium hydrogen phthalate with chemical oxygen demand of 200 mg·L-1. The compressed sensing algorithm is used to decompose the signal in the wavelet domain, and the high frequency coefficients are obtained. Using the random Gaussian matrix as the observation matrix of the compression sensing algorithm, the compression ratio is set to 2, and the high frequency coefficients are observed. The orthogonal matching algorithm is used to recover the sparsity of the high frequency wavelet coefficients to achieve the denoising. At the same time, for the traditional wavelet threshold denoising, the soft-threshold filtering method is used to denoise the spectral data, and the wavelet base is daubechies 4. In order to verify the feasibility of the noise reduction algorithm, the spectral signals of a stream and domestic sewage were collected, and the above two methods were used to denoise the spectral signal. The experimental results show that the compressed sensing algorithm based on wavelet transform is suitable for the on-line water quality detection system based on UV-Vis spectroscopy. The method can effectively denoise under the premise of preserving the absorption characteristics of the original spectral signal of the water sample, and the denoising effect is better than the wavelet threshold denoising algorithm. Compared with the wavelet threshold denoising algorithm, the SNR is increased by 12.201 5 dB, the RMSE is neduced by 0.009 3, and the PSNR is increased by 5.299 dB. The proposed method not only avoids the problem of threshold selection in wavelet threshold denoising, but also effectively suppresses the noise in the reconstruction process. This method provides a new solution for direct spectroscopy to detect water quality parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 844 (2018)
Study on the Interaction of Aconitine and Armyworm DNA by UV Spectroscopy and ITC Method
LIU Ye, ZHAO Wei-wei, LI Zong-xiao, CHENG Hua-lei, and HE Huan
DNA is a vector for the genetic information of organisms. It is important to study the interaction between drugs and DNA and to explore its reaction mechanism, the design and synthesis of new drugs. The dissolution behavior of aconitine in water was studied for the first time by microcalorimetry. By using isothermal tiDNA is a vector for the genetic information of organisms. It is important to study the interaction between drugs and DNA and to explore its reaction mechanism, the design and synthesis of new drugs. The dissolution behavior of aconitine in water was studied for the first time by microcalorimetry. By using isothermal titration calorimetry, UV-Vis Absorption Spectroscopy and molecular simulation, the interaction between aconitine and armyworm DNA, salmon sperm DNA and calf thymus DNA was discussed. The results showed that the dissolution process of aconitine in aqueous solution was a simple first-order reaction and t1/2=0.691 h. There were two types of combinations during interactions between aconitine and the three different DNAs. The type Ⅰ combination was found to bean enthalpy-driven process. The equilibrium constant of combination (Ka1) was larger with the value of about 105. The number of binding sites (n1) was 0.40~0.60. The reaction took place in the groove areas. With regard to type II combination, the values of Ka2 was 103, and n2 was larger than n1. Lower equilibrium constant of combination demonstrated that the drug ligands just reacted with DNA on the surface instead of entering into the interior of macromolecules. Molecular simulation studies showed that the combination of aconitine and three DNAs occurred in the groove areas. The hydrogen bondwas mainly interactions during interactions between aconitine and the three different DNAs, and the ester groups on the C8 of the aconitine molecule were related to the armyworm DNA, the salmon sperm DNA and the calf thymus DNA respectively. Their bases were specifically identified by T33, T34 and G16, C9, C8. The similarity between the calculated binding energy and the measured ΔG demonstrated that the theoretical calculations were consistent with the experimental results. It can be seen that there is good agreement between the theoretical calculations and experimental results in this work..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 851 (2018)
Detection Method Progress and Development Trend of Organic Pollutants in Soil Using Laser-Induced Fluorescence Spectroscopy
WANG Xiang, ZHAO Nan-jing, YU Zhi-min, MENG De-shuo, XIAO Xue, ZUO Zhao-lu, MA Ming-jun, YANG Rui-fang, and LIU Jian-guo
The organic pollution of soils, which is second to the pollution of air and water, has become a serious environmental problem all around the world, However, it has to face a range of challenges such as multi-pollutants, limited detection methods and widespread hazards . Laser induced fluorescence (LIF) spectroscopy tecThe organic pollution of soils, which is second to the pollution of air and water, has become a serious environmental problem all around the world, However, it has to face a range of challenges such as multi-pollutants, limited detection methods and widespread hazards . Laser induced fluorescence (LIF) spectroscopy technique has become a powerful method for the analysis of the elemental composition of materials.Due to the fact that it requires no need for sample preparation and rapid detection in Laboratory and on site conditions, it has been widely applied in a large variety of fields, such as environmental analysis, biological detection and biological science. Many researchers have focused on the research of quantitative Analysis with LIF. This paper gives a review of the mechanism of LIF technique and the progress of LIF technology, describing the progress development of LIF technology on organic pollution in soils, the qualitative and quantitative analysis methods of oil pollutants, polycyclic aromatic hydrocarbons and organic pesticides in soils are included in the LIF detection in soils. In addition, this paper describes the instrument development of LIF technology and inquiries about the developing prospect of LIF instruments, and also provides a reference on the developing prospect of LIF instruments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 857 (2018)
Influence of Chlorophyll Fluorescence on the Retrieval Accuracy of Carbon Dioxide
JIANG Yun, YE Han-han, WANG Xian-hua, DUAN Feng-hua, and WU Hao
As a major error of CO2 retrieval, atmospheric scattering effect hampered the accuracy of CO2 retrieval. The stability of oxygen in the atmosphere is used in scattering correction for atmospheric CO2 inversion, such as the photon path length probability density function (PPDF) method. However, the presence of plant chlAs a major error of CO2 retrieval, atmospheric scattering effect hampered the accuracy of CO2 retrieval. The stability of oxygen in the atmosphere is used in scattering correction for atmospheric CO2 inversion, such as the photon path length probability density function (PPDF) method. However, the presence of plant chlorophyll fluorescence in the light irradiation of O2 A will affect the PPDF parameter retrieval as well as the accuracy of CO2 inversion. As the vegetation fluorescence is weak, in the previous CO2 inversion did not cause enough attention. Based on the study of global vegetation fluorescence distribution, the influence of fluorescence on atmosphere CO2 column content (XCO2) was simulated and analyzed. The influence of fluorescence under the aerosol free, aerosol and surface albedo condition is simulated, the result indicates that when the aerosol is not taken into account, the fluorescence intensity increases from 0.1 to 1.8, which results in a deviation of 0.1 to 2 (10-6) for the inversion of XCO2. Inversion of XCO2 results in a deviation of 0.1 to 3 (10-6) when considering the influence of aerosol and surface reflectance. This research shows that chlorophyll fluorescence cannot be neglected in high precision CO2 inversion..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 864 (2018)
Reconstruction Simulation with Quantum Dots Spectral Imaging Technology
WANG Ying-jun, ZHOU Jin-song, WEI Li-dong, ZHANG Gui-feng, ZHU Dong-liang, GUO San-wei, TANG Hong-wu, and PANG Dai-wen
In order to meet the requirement of compact type and lightweight for spectral imaging system in airborne and satellite platform, and to overcome the limitations of optical splitting system in current spectral imaging technology such as complex structure and high cost, for the first time we present the design of spectraIn order to meet the requirement of compact type and lightweight for spectral imaging system in airborne and satellite platform, and to overcome the limitations of optical splitting system in current spectral imaging technology such as complex structure and high cost, for the first time we present the design of spectral imaging based on quantum dots. In this method, a strip of quantum dots array is placed in front of the focal plane of telescope lens and absorption properties of quantum dots materials is applied to modulate the incident spectrum of the target, then least square method is applied to establish the spectral reconstruction model of the target. Finally, the spectral and spatial information of the target is obtained with the method of push broom and spectral reconstruction. The quantum dots spectral imaging technology has the advantages of high spectral resolution, high energy availability, small size, wide spectral range and low cost. More important, the effects of different spectral intervals and noises on the reconstructed spectral resolution and their impact on the accuracy or distortion of the reconstructed spectra are analyzed. The results show that the spectral resolution increases with the decrease of the spectral interval, and the accuracy and resolution of the reconstructed spectrum are reduced with the increase of the noise level. What's more, the accuracy of reconstruction can be improved by appropriately increasing the spectral interval. With a comparison of the simulation results with the known data cube, the feasibility of the technology is verified, and the results show that the quantum dots spectral imaging possesses higher quality. In conclusion, quantum dots provide a new approach for spectral imaging technology, which has wide applications in the field of aerospace and other miniature spectral remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 869 (2018)
Method for Obtaining Truth Color Values Based on Relative Spectral Power Distribution of Light Source
WANG Hong, YANG Jian-feng, XUE Bin, SONG Yan-song, and XIE Pei-yue
Chang’E-3 panoramic camera is designed for color imaging, and a color calibration has to be performed before the launch of the detector. The first step when calibrating the camera is to obtain the ground truth color values of the samples. The color values measured by the traditional method have some significant deviatiChang’E-3 panoramic camera is designed for color imaging, and a color calibration has to be performed before the launch of the detector. The first step when calibrating the camera is to obtain the ground truth color values of the samples. The color values measured by the traditional method have some significant deviations with the actual values and differ at the color difference and human visual perception. When the values are used to perform calibration, the color differences are not ideal, and the images have a negative effect on human perception. In this study, the white reference coordinates adopted in transformation matrix between XYZ and sRGB color space are redefined by using the relative spectral power distribution of D65 calibration light source. After that, based on the CIE color-computing formula and H. Grassmann color mixing law, the transformation matrix to recalculate RGB color values from XYZ color space is modified. In addition, by means of calculating spectral tristimulus values in sRGB with modified matrix, we give analysis to the factors that caused color distortions. The results of the ground experiment showed that the color differences DE76 for cameras A and B after calibration reduced 0.8 and 0.73 respectively compared with those achieved using traditional method. And when the calibrated matrix is used to correct images taken on lunar surface, color difference reduced 26.50% and 34.47% respectively, and the images have a positive effect on human perception..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 877 (2018)
Distribution of Aloe-Emodin and Its Color and Spectral Properties under the Influence of ZnO NPs
ZHANG Lan-lan, XU Chang-shan, CHEN Ze-lin, SHAO Hai-ling, ZHANG Hai-jiao, and QIAO Jin
Zinc oxide nanoparticles (ZnO NPs) have unique physical and chemical properties and important application values in many fields, which has also been resulted the consequence that it was released into different environment, and increased the interaction with creatures, which is the most important aspect of the toxic effZinc oxide nanoparticles (ZnO NPs) have unique physical and chemical properties and important application values in many fields, which has also been resulted the consequence that it was released into different environment, and increased the interaction with creatures, which is the most important aspect of the toxic effects of ZnO NPs. Aloe is a lily family of evergreen and fleshy herbs, which has important ornamental and medicinal value, Aloe-emodin (Aloe emodin, AE) is an important pigment molecule in aloe, which is also an important active ingredient of aloe as a medicinal plant. In this work, from a new perspective, the distribution of AE in leaves was investigated through the longitudinal slicing method with fluorescence microscopy, and which was comprehensively understood, and then the interaction between ZnO NPs and AE was studied. The changes of the color of AE and its fluorescence spectra under the influence of ZnO NPs were observed and analyzed. The results showed that the trend of the color change of AE solution was from light yellow through orange yellow, orange to orange red; moreover, compared with the control group, the ZnO NPs accelerate the changes of the relative intensity of the main the emission peaks located at 540 and 580 nm, increased the ratio of I540/I580. The above results indicate that ZnO NPs have obvious negative effects on AE, which provides more information for a comprehensive evaluation of the bio-risks of ZnO NPs on aloe and other related plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 883 (2018)
Spectroscopy Method used in Temperature and Electron Density of Pantograph-Catenary Arc
XING Li-cheng, ZHANG Xiao-dong, LIU Biao, CUI Xiao-yan, and YANG Jun-feng
Train speed is limited by many factors, in which the off-line between catenary and pantograph has a great impact on power quality. Because of sliding contact mode, the pantograph and catenary are seriously worn. The arc generated by offline in pantograph and catenary is one of the main reasons of the abrasion on pantogTrain speed is limited by many factors, in which the off-line between catenary and pantograph has a great impact on power quality. Because of sliding contact mode, the pantograph and catenary are seriously worn. The arc generated by offline in pantograph and catenary is one of the main reasons of the abrasion on pantograph and catenary, but the arc temperature is very high, and it has ionization characteristics, so the general sensors cannot be placed in the arc to measure characters. Considering the arc’s feature, spectroscopy is important to study temperature and electron density of arc, and it is obviously advantaged. With this basis, researchers can find new wear-resistant material or arc-extinguishing method. We select specific spectrums of Cu as the studying object for catenary is made by copper alloy. We calculate arc temperature using Boltzman mapping method through spectral information experimentally measured. The result shows that temperature is not particularly high cause of short sustained time, and we know that the temperature is mainly affected by sustained time. Then we using deconvolution method to calculate Stark broadening, and according Stark broadening calculate electron density of the arc. The results show that the electron density of pantograph-catenary arc is not special different from electron density of welding arc. Spectroscopy is a convenient and accurate method in the calculating of temperature and electron density of arc..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 890 (2018)
Development of Lab-on-Chip Spectrophotometric Silicate Sensor in situ Analysis of Seawater
CAO Xuan, ZHANG Shu-wei, CHU Dong-zhi, WU Ning, MA Hai-kuan, and MA Ran
A new Microfluidic continuous flow analysis sensor is established for the determination of soluble silicate in seawater based on the reaction of silicate with ammonium molybdate to form a yellow silicomolybdate complex, and further reduction to silicomoIybdenum blue by ascorbic acid. Theanalyzing cycle of the sensor isA new Microfluidic continuous flow analysis sensor is established for the determination of soluble silicate in seawater based on the reaction of silicate with ammonium molybdate to form a yellow silicomolybdate complex, and further reduction to silicomoIybdenum blue by ascorbic acid. Theanalyzing cycle of the sensor is about 300 s, Double optical absorbance path method is adopted in this sensor to expand the measuring range, and the linear range of the sensor reaches 0～400 mol·L-1 with limit of detection of each absorbance cell were 45.1 nmol·L-1 and 1.6 μmol·L-1 respectively. There are no evident effects on the performance of determination of this sensor when samples’ salinity is above 15, and the actual water the recovery rate is between 98.1%～104.0%. In November 2015, this sensor was deployed in a research vessel for a sea trail in Jiaozhou Bay involving 20 sites, the data acquired from the sensor were compared with those from sampling then by lab analyzing. The results obtained in situ coincide with those from lab analyzing, and indicating This sensor has the advantages of high accuracy, simple and high integration, water consumption, and strong anti-interference ability, and suitable for in situ silicate monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 895 (2018)
Study on Nondestructive Testing for CuAz Preservative-Treated Bamboo with Synchrotron Radiation X-Ray
PENG Guan-yun, LIU Xing-e, YANG Shu-min, QIN Dao-chun, XIE Hong-lan, DENG Biao, DU Guo-hao, TONG Ya-jun, and XIAO Ti-qiao
The third-generation synchrotron radiation X-ray has many advantages such as high brightness, continuous spectrum, wide spectral range, high spatial resolution and high resolution and so on, which helps to realize the adjustable energy and precise calculation of its spectrum. And it also has the competitive advantage oThe third-generation synchrotron radiation X-ray has many advantages such as high brightness, continuous spectrum, wide spectral range, high spatial resolution and high resolution and so on, which helps to realize the adjustable energy and precise calculation of its spectrum. And it also has the competitive advantage of obtaining the edge enhancement image for high contrast imaging of low Z materials. In this paper, the Cu distribution was obtained by dual energy subtraction imaging and the characteristic microstructures of CuAz preservative treated bamboo were investigated systemically with XPCM at Shanghai Synchrotron Radiation Facility (SSRF).The results showed the testing techniques were expected to the important precision nondestructive methods for preservative treated bamboo..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 901 (2018)
Spectral Detection of Damaged Level of Larch Affected by Jas’s Larch Inchworm
HUANG Xiao-jun, XIE Yao-wen, and BAO Yu-hai
In recent years, the Mongolian Jas’s Larch Inchworm disaster have been increasing and gradually approaching the Daxinganling area, which will threaten the safety of the forest ecosystem in the north of China. It is necessary to replace the Mongolian traditional detection method with the modern remote sensing monitoringIn recent years, the Mongolian Jas’s Larch Inchworm disaster have been increasing and gradually approaching the Daxinganling area, which will threaten the safety of the forest ecosystem in the north of China. It is necessary to replace the Mongolian traditional detection method with the modern remote sensing monitoring method, and it is important to control the rule of occurrence and development of the insect at the first opportunity. A detection model was developed for rapid and wide range remote sensing monitoring of Jas’s Larch Inchworm damage based on spectral analysis technology. Spectra in situ measurements were conducted for healthy larch and mild, moderate, severe damaged larch to compute and compare the raw spectra and continuum removal spectra. On this basis, spectral sensitive bands and sensitivities of continuum removal spectra were uncovered. Then some spectral characteristic parameters were obtained by the first derivative transformation of continuum removal spectrum, and its change features vs damaged level of larch were analyzed to construct the detection model based on CART (classification and regression tree) algorithm. The results showed that the sensibility of continuum removal spectra was more significant than that of raw spectra, especially in 480～520 nm (blue edge), 640～720 nm (red edge) and 1 416～1 500 nm (short wave infrared valley). In these bands, the value for the sensitivity of continuum removal spectra was between 0.1 and 0.2. At the same time, it appeared sensitive peaks in the sensitive bands. With the increase of damaged level, the sensibility of continuum removal spectra had an enhanced trend which was more evident compared with raw spectra. In addition, the sensitive peak position of the continuum removal spectra in the blue band was shifted to the short wave direction, that is, 502 nm→490 nm, and the spectral sensitive peak position in the red valley and red edge, short wave infrared valley moved to the long wave direction, that is, 664 nm→672 nm and 1 436 nm→1 448 nm. Furthermore, the normalized reflectance of red valley position and short wave infrared valley position as well as areas of red valley and short wave infrared valley were found a trend of rising. First derivative of continuum removal spectra had obvious in response for damaged level in blue edge and red edge. Moreover, the band peaks were arisen. The red edge position blue shift arose (718 nm→700 nm) as the damaged level increased, while the slopes and areas for blue edge and red edge decreased. Hence, the CART model that was established based on several continuum removal spectral parameters such as red edge slope, normalized reflectance of red valley position and short wave infrared valley position, areas of red valley and short wave infrared valley and both slope and area of blue edge had superior detection ability in the damaged level of larch. Compared to multi-linear regression model, the CART model performed better with the Kappa value of 0.875. These results will play important roles on remote sensing monitoring of the damage of Jas’s Larch Inchworm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 905 (2018)
Inversion of Soil Organic Matter Content in Wetland Using Multispectral Data Based on Soil Spectral Reconstruction
CHEN Si-ming, ZOU Shuang-quan, MAO Yan-ling, LIANG Wen-xian, and DING Hui
Soil organic matter (SOM) is an important element of wetland ecosystem. Quick and wide monitor of SOM content with multispectral remote sensing technique has the vital significance to protect wetland ecosystem. More previous studies on the estimation of SOM content used hyperspectral analysis, while using multispectralSoil organic matter (SOM) is an important element of wetland ecosystem. Quick and wide monitor of SOM content with multispectral remote sensing technique has the vital significance to protect wetland ecosystem. More previous studies on the estimation of SOM content used hyperspectral analysis, while using multispectral was less. The main reason is that the spectral anomaly of multispectral data caused by spectral mixing of different objects affects the inversion accuracy of SOM content in wetland. Therefore, to avoid the spectral anomaly, this paper took the Shanyutan wetlands of Minjiang River Estuary as a survey region, trying to use Linear Spectral Unmixing Model(LSUM) to separate the pixel of original image and reconstruct the soil spectrum. Then, the correlation analyses between 2 different spectra (the raw spectrum and the reconstructed spectrum) and SOM content were done. Finally, according to correlation results, an inversion model for SOM content was established. The result showed that LSUM can effectively eliminate vegetation endmembers of the original image, reducing the reflection interference of most roads and buildings. The reconstructed spectral characteristic curve was closer to the spectral curve of soil under natural condition. It indicated that the effect of spectral reconstruction was remarkable; Compared to the correlation coefficients between 2 different spectra and SOM content, the reconstruct spectrum was more appropriate for reflecting the correlation between the soil spectrum and soil organic matter in the study area; using the reconstructed spectrum to build the predicting model could obtain more robust prediction accuracies than using the raw spectrum. Its values of R2 and F were increased by 0.124 and 2.223 respectively. And RMSE was reduced by 0.106. Moreover, through the 1∶1 line test, model of the reconstructed spectrum had a better fitting between the predicted and the measured. These results suggested that using LSUM has been proven to be effective in removing the spectral anomaly, ensuring a transferrable model for SOM content under natural condition. The study will provide some practical technology to monitor the SOM content in wetland by multispectral data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 912 (2018)
Effects of Different Visible Spectra on the Quality of Mouse Oocytes and Early Embryos
WANG Yi-ming, ZHANG Bing, WANG Ting, ZHANG Shu, YU Ji, WU Chuang, and TIAN Ning
During the process of in-vitro extraction, oocytes or early embryos can’t avoid the visible light stimulation. However, the effects of light exposure on the development quality in vitro are still unclear. This work used three technologies of in-vitro culture, noninvasive imaging (full-field optical coherence system) anDuring the process of in-vitro extraction, oocytes or early embryos can’t avoid the visible light stimulation. However, the effects of light exposure on the development quality in vitro are still unclear. This work used three technologies of in-vitro culture, noninvasive imaging (full-field optical coherence system) and three-dimensional reconstruction. Under the prerequisite of ensuring the same light intensity and the same exposure time, we were the first to use the real-time and in-situ method to study the effects of different visible spectra on the development quality of mouse oocytes and embryos based on the morphology. It was found that (1) compared with the white light illumination, the blue-violet light significantly reduced the rates of the germinal vesicle breakdown and the first polar body extrusion of mouse oocytes. While under the green and red light illumination, these two rates greatly increased. (2) Compared with the white light group, the blastocyst rate reduced and apoptosis increased greatly in the blue-violet light group, while the opposite was true for the green and red light groups. It indicated that blue-violet light was harmful to the development of mouse oocytes and early embryos, while the green light and red light showed little damage..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 918 (2018)
The Relationship of the Leaf Surface Wettability and Degree of Reflectance Polarization
GAO Xiao-yu, and LU Shan
Urban greening plants can improve the quality of atmospheric environment effectively due to their dust catching property, which mainly influenced by surface characteristics and wettability. We studied the relationship between leaf surface wettability and polarized reflection characteristics because they are both relevaUrban greening plants can improve the quality of atmospheric environment effectively due to their dust catching property, which mainly influenced by surface characteristics and wettability. We studied the relationship between leaf surface wettability and polarized reflection characteristics because they are both relevant to the surface roughness of leaves. The contact angle of water droplet on leaf surface and the polarized reflectance spectrum from eight major plant species for urban greening in Changchun were measured by Kruss DSA 100 drop shape analysis system and multi-angle spectrum measurement system. We found the characterized band of eight plants through correlation analysis. The influence of wettability on the degree of polarization (DOP) varying with viewing angles was inquired and analyzed quantitatively in the characterized band. The results showed that when the viewing azimuth was fixed at 180°, the DOP spectrum within 400~1 000 nm increased to a maximum, and then began to decline varying with zenith angles from 0° to 60°. The correlation analysis between the deviation from 100° contact angle (θ) and the viewing zenith (θ0) showed that they were in a linear relationship, with the determination coefficient of 0.82. In this paper, the research achievements will provide feasible suggestions to the options of urban greening plant species in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 923 (2018)
Comparative Study on Microstructure of Flocculant/Catkin with Natural Fiber
CHEN Hang, MEI Chang-tong, LUO Wen, XU Mo-su, REN Yi, and YIN Wen-xuan
The morphology and microstructure of catkins or flower cluster of poplar/willow were studied comparing with cotton/natural silk by the means of stered microscope, scanning electron microscope(SEM) and total reflection (ATR) spectra (FTIR), respectively. The experimental results showed that the morphology of cotton/silkThe morphology and microstructure of catkins or flower cluster of poplar/willow were studied comparing with cotton/natural silk by the means of stered microscope, scanning electron microscope(SEM) and total reflection (ATR) spectra (FTIR), respectively. The experimental results showed that the morphology of cotton/silk fiber was thicker and had excellent tensile performance, while poplar catkin fiber was shorter with,less tensile properties. The FTIR analysis showed that the main chemical compositions of cotton and poplar catkins were cellulose and the stretching vibration absorption peak of hydroxyl(—OH) groups in hydrogen bond network of cotton fiber was significantly stronger than poplar catkin fiber.This may explain why the tensile properties of cotton fiber length, fiber flocculant is superior to the catkins of poplar and willow.Silk fiber is different from plant fiber,such as,cotton,poplar catkin) whose main structure is amide structure. Their microstructure difference determines the different properties and applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 929 (2018)
Experimental Study on Sensitivity of In-Vitro Caries Detection with Thermophotonic Lock-in Imaging (TPLI)
XIAO Bo-cheng, and LIU Jun-yan
According to the World Oral Health Report 2003, dental caries remains a major public health problem in most countries. Early detection is very important to the diagnosis and treatment of caries. The traditional dental caries detection methods, such as visual examination, probes, X-ray and other detection methods with lAccording to the World Oral Health Report 2003, dental caries remains a major public health problem in most countries. Early detection is very important to the diagnosis and treatment of caries. The traditional dental caries detection methods, such as visual examination, probes, X-ray and other detection methods with low sensitivity and strong subjectivity, cannot meet the requirements of detecting early caries with high accuracy, reliability and specificity. Therefore, it is of great significance to find a kind of non-destructive, non-contact, high sensitive and high specific method to detect early caries. thermophotonic lock-in imaging (TPLI) detection technology based on photothermal effect is a non-destructive detection technology, and TPLI has the merit of high detection efficiency, large detection area and understandable detection result.Therefore, in this paper, artificially created demineralized on enamel of dental tissue was detected by TPLI, the detection ability of TPLI for caries regions which were selected on smooth surface, adjacent surface and the occlusal surface was investigated. The experimental samples were five molar teeth that had health surfaces and no visible defects, stains, or cracks. Two of them were spliced adjacently by epoxy glue to simulate adjacent surface. All samples were created 5 mm×5 mm rectangular windows on the smooth respectively , adjacent and occlusal surface, other surfaces were coated by acid-proof nail polish. Furthermore, the samples that artificially created demineralized on three different surfaces were imaged by TPLI and X-ray radiography after demineralized two days in the lactic acid gel (pH=4.5). The results showed that the amplitude value of caries area was larger than that of healthy area the phase delay became bigger due to demineralization. The amplitude images and phase images of TPLI were more sensitivity and more specificity to the artificial demineralization than the X-ray radiography. The smooth surface of a sample was selected to demineralize for different days, 1, 2, 4 and 6 d. Then the sample was imaged with TPLI and a X-ray radiography to decide quantitatively the degree of demineralization to prove the detection ability of TPLI. The results showed that the difference value of amplitude (healthy area amplitude and caries area amplitude) was 3.82 and the difference value of phase was 10.57° after 1d demineralization. However, X-ray detection method cannot recognize caries within demineralized 6d. The amplitude images and phase images of TPLI were consistent changes with caries time, and can found the caries very early. This paper proves the significance of TPLI to diagnosis and treatment of teeth..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 933 (2018)
Retrieval of Soil Organic Carbon Based on Bi-Continuum Removal Combined with Orthogonal Partial Least Squares
CONG Lin-xiao, HUANG Min, LIU Xiang-lei, and QI Yun-song
Soil Organic Carbon (SOC) is important for soil fertility and can be quickly retrieved by Visible Near-Infrared (VNIR) Spectroscopy, which provides a basis for regional monitoring and quantitative remote sensing. For the traditional Continuum Removal (CR) method, only the upside absorption characteristics of the reflecSoil Organic Carbon (SOC) is important for soil fertility and can be quickly retrieved by Visible Near-Infrared (VNIR) Spectroscopy, which provides a basis for regional monitoring and quantitative remote sensing. For the traditional Continuum Removal (CR) method, only the upside absorption characteristics of the reflection spectrum envelope is considered in multiple regression, which results in the absence of CR downside or predictive spectral background information, thus the variables usually do not reflect the emission characteristics of all band . In this paper, a new method named BCR-OPLS which combines Bi-Continuum Removal (BCR) and Orthogonal Partial Least-Squares (OPLS) is proposed for SOC content retrieval, conducting a test upon 245 Chinese soil samples containing VNIR (350~2 500 nm) diffuse reflectance spectra downloaded from ICRAF-ISRI Database. With BCR-OPLS method, both the upside and downside continuum removal are included in analyzing the characteristics of the spectra. After building the comprehensive and classification model for soils of different types mixed and alone, an SOC index applicable to certain type of soil is derived. The role of power function and logarithmic function playing in skewness correction for the SOC reference values' statistical distribution is discussed. As a result, by introducing bilateral-continuum information, the SOC retrieval ability of the BCR-OPLS model is significantly improved (Coefficients of determination R2=0.9 and Root mean square error Estimated RMSEE=0.26%) compared with the initial R-PLSR model (R2=0.69, RMSEE=0.45%), and the SOC retrieval accuracy of a certain type is further improved. For example, when predicting SOC of the Orthic Ferralsols (using 400, 590 and 920 nm), R2 and RMSEE improved to be 0.94 and 0.21% respectively. In summary, BCR-OPLS enhances the robustness of spectral feature diagnostics by improving the accuracy of both comprehensive and classified SOC inversion based on full-spectrum, and derives a simple SOC prediction index composed of several wavelength variables for a certain type of soil through the translatability of relationships among BCR and SOC content revealed in loading scatter plot of OPLS, which are selected according to the loadings' trend and Variable Importance in Projection. Finally, BCR-OPLS strengthens the connection between experienced physical absorption analysis and obscure statistical multiple regression method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 941 (2018)
Pressure Measurement of Each Gas in Alkali-Metal Vapor Cell with a Mixed Gas Based on Saturated Absorption Spectrum
CHI Hao-tian, WANG Xu-lin, and QUAN Wei
Alkali-metal vapor cell is one of the most important core component. As a sensitive device, it is often applied in the measuring device of the ultra-high sensitive inertial and magnetic field, which is based on the atomic spin exchange relaxation free regime. The content of the gas in the alkali-metal vapor cell will hAlkali-metal vapor cell is one of the most important core component. As a sensitive device, it is often applied in the measuring device of the ultra-high sensitive inertial and magnetic field, which is based on the atomic spin exchange relaxation free regime. The content of the gas in the alkali-metal vapor cell will have an enormous influence on the relaxation of the atoms and the selection of other system parameters. Therefore, the precise measurement of each gas pressure is of great significance. Pressure broadening and frequency shift will occur when there is gas in the alkali-metal vapor cell. We merely took pressure broadening into account, because pressure broadening was much larger than the natural broadening and Doppler broadening. Since both pressure broadening and frequency shift had a function relationship with the gas pressure, we proposed a method and experimental equipment to measure gas pressure based on saturated absorption spectrum. Firstly, we obtained the optical depth curve by scanning the absorption spectrum of alkali metal atoms, and fitted the curve by Lorenz function. We were able to obtain the superimposed pressure broadening and frequency shift of single alkali metal atom, which was caused by mixed gases in the cell. Then, we solved the simultaneous equations to get the pressure of each gas, based on the known pressure broadening and frequency shift of single alkali metal atom, which were caused by a single type and specific pressure gas. The maximum number of gas pressure we can measure was 4n in the mixed gas, when there was n kinds of alkali metal atoms. Simulation results showed that the method was applicable when the incident laser was not completely absorbed. The effect on measurement accuracy caused by laser power and frequency fluctuations is insignificant. Temperature fluctuation is very significant. We should take measures to achieve the accurate control of temperature..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 948 (2018)
Study on Phase Transition Process of NaCl-H2O and NaCl-KCl-H2O at Low Temperature with in Situ XRD
YANG Hong-jun, CHAI Xiao-li, WANG Min, and LI Bing
The diffraction patterns of two systems——NaCl-H2O and NaCl-KCl-H2O at low temperature were determined with in situ XRD. The details of systems’ phase transition were further obtained. The solids were analyzed according to the patterns. For NaCl-H2O system, the phase transitions were different because of their differentThe diffraction patterns of two systems——NaCl-H2O and NaCl-KCl-H2O at low temperature were determined with in situ XRD. The details of systems’ phase transition were further obtained. The solids were analyzed according to the patterns. For NaCl-H2O system, the phase transitions were different because of their different compositions. For the solution of 26.25% NaCl the solids included ice, NaCl, NaCl·XH2O(X<2), NaCl·2H2O in temperature range of -20~-25 ℃, for the solution of 25.70% NaCl the phase transition did not occur under experimental conditions. For NaCl-KCl-H2O system, the phase transitions were different too. For the solution of 20.03% NaCl and 10.19% KCl the solids were KCl and NaCl in temperature range of 0~-25 ℃, for the solution of 22.40% NaCl and 7.28% KCl the solid was KCl only in temperature range of -10~-25 ℃, as for the solution of 21.90% NaCl and 6.46% KCl there was no phase transition under the experimental conditions. The results show that there are some differences between the experimental and theoretical results due to their different states. The combination of sodium chloride with water results in the appearance of NaCl·2H2O. Crystallization processes as well as temperature control the occurrence of the phase transition. The phase transitions of the systems are results from comprehensive influences of several factors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 953 (2018)
Molecular Speciation of Phosphorus in an Organically Bound Phosphorus Fertilizer with High Phytoavailability Characterized by Multiple
LIU Jin, YANG Jian-jun, Yongfeng HU, LI Ju-mei, ZHANG Xiu, and MA Yi-bing
While the global phosphorus (P) resources is running low, the environmental issues due to over-application of P fertilizers become increasingly urgent. There is a more pressing need than ever before to develop new types of P fertilizers with high phytoavailability with agronomic, environmental and sustainability benefiWhile the global phosphorus (P) resources is running low, the environmental issues due to over-application of P fertilizers become increasingly urgent. There is a more pressing need than ever before to develop new types of P fertilizers with high phytoavailability with agronomic, environmental and sustainability benefits. Compared to generally applied inorganic P fertilizers, organically bound P fertilizers are less prone to soil fixation, and could remain relatively high mobility from where the fertilizer is added to the rhizosphere for crop utilization. Developing organically bound P fertilizers is increasingly recognized as an efficient way to fundamentally solve the current problem induced by the low phytoavailability of inorganic P fertilizers. In recent few years, related studies are becoming popular, but researches on the speciation of the emerging organically bound P fertilizers are not well-documented until now. Various organically bound P fertilizers were developed and their P phytoavailability were tested. Our previous study showed that the starch-bound P fertilizer had high P efficiency. Since the phytoavailability of P fertilizers was a function of the P species present in the fertilizer and the transformations in soils after application, this current study probed P speciation in the starch-bound P fertilizer at the molecular level by solution P-31 nuclear magnetic resonance (P-NMR) and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy. To obtain quantitative results by P-NMR analysis, the fertilizer sample was hydrolyzed to α-limited dextrin, and then dissolved with dimethyl sulfoxide solution (45%). Nicotinamide adenine dinucleotide was added as an internal reference standard. It indicated that the total P concentration in the studied fertilizer by NMR agreed with that by the colorimetric chemical method. Phosphorus in the starch-bound P fertilizer was mainly presented as orthophosphate monoester, representing 75.8% of total P. Orthophosphate diester accounted for 17.3% of total P, while inorganic P only 6.9%. Furthermore, the XANES spectra of the P fertilizer closely resembled that of phytic acid, and was lack of the characteristic features of inorganic P species. Conclusively, these results illustrated the dominance of organic orthophosphate monoester in the studied fertilizer. Combining state-of-the-art of spectroscopic analysis, this study provides an important basis for further studies on the high phytoavailability mechanisms of organically bound P fertilizers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 958 (2018)
A Method to Fit Low-Quality Stellar Spectrum
WU Ming-lei, PAN Jing-chang, YI Zhen-ping, and WEI Peng
The stellar continuum is a sort of spectrum whose light intensity changes continuously and smoothly with wavelength (frequency) due to blackbody radiation. Each observed spectrum contains continuous spectra, spectral lines and noises. The classification of stellar is mainly based on the spectral lines of the spectrum, The stellar continuum is a sort of spectrum whose light intensity changes continuously and smoothly with wavelength (frequency) due to blackbody radiation. Each observed spectrum contains continuous spectra, spectral lines and noises. The classification of stellar is mainly based on the spectral lines of the spectrum, relative intensity of the continuum and other characteristics of the spectrum. The distribution of the stellar continuum and the contour of the lines are determined by the stellar atmospheric parameter, so the stellar atmospheric parameter can be estimated from the continuum and the spectral lines. Therefore, the main problem of the spectral data processing is to extract the continuum and the lines. The current algorithms for stellar continuous spectral extraction are mainly polynomial approximation, median filtering, morphological filtering and wavelet filtering. However, these methods for the robustness of low-quality spectral processing are not very satisfying. Therefore, it is necessary to study a new algorithm for extracting the continuous spectrum from the low-quality spectra. In this paper, a fitting method for low-quality stellar spectrum based on Monte Carlo is proposed after careful analyses of low-quality stellar continuum. The method is used to automatically interpolate at the point where the spectrum is not in the range of the star spectrum with Monte Carlo, so each wavelength corresponds to a flow point, and then the low-order polynomial iterations are fitted to these flow points for obtaining the continuous spectrum. In order to verify the robustness of the algorithm for low-quality spectral continuum extraction with different SNRs, we use different SNRs to simulate different low-quality spectrum by adding different Gaussian white noise to the original spectrum. The result shows that the proposed algorithm has high accuracy and robustness to the fitting of low-quality spectrum with different SNRs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 963 (2018)
Multi-Spectral CT Sequence DCM Fusion Algorithm Based on Priori Components
ZHAO Dan, CHEN Ping, HAN Yan, and LI Yi-hong
Multi-spectral CT imaging is to characterize the different components in the CT images of different spectral ranges. For more convenient displaying all components physical information in an image, it is necessary to study the fusion method of multi-spectral CT sequence. But the commonly used fusion methods, such as weiMulti-spectral CT imaging is to characterize the different components in the CT images of different spectral ranges. For more convenient displaying all components physical information in an image, it is necessary to study the fusion method of multi-spectral CT sequence. But the commonly used fusion methods, such as weighted average method and wavelet transform fusion method, are mainly for the optimization of image information. The physical properties of the components can not be expressed, so that the gray scale of the fused image without physical representation affects the quantitative detection of CT. A multi-spectral CT sequence DCM fusion algorithm based on priori components with physical characterization was presented. First, we got multi-spectrum projection sequence by Imaging method separated by energy spectrum filtering and the CT sequence with different energy spectrum can be obtained by TV-OSEM reconstruction algorithm. Second, the traditional DCM model and the improved DCM model were used to fuse the multi-spectral CT sequences. The traditional DCM model was strictly single energy, considering the non-strict monocular characteristic of the filtered energy spectrum. The fusion result can not accurately characterized all the components in the object sequence. To solve this problem, an improved DCM model was proposed. In the improved DCM model, a new voxel definition was selected and a metallic priori component was introduced as a reference substance in the multi-spectral CT sequence. The Prior component was used to calibrate other substances in the fusion results. Thus accurate distribution of each component in the CT sequence was achieved by calibration of the fusion results. Simulation result, the method can realize multi-spectral CT sequence fusion from the perspective of the physical representation. while satisfying the different components distinction of the CT sequence, the gray scale of its fused image had physical reference. This method is beneficial to the subsequent CT quantitative detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 968 (2018)
A New Spectra Transfer Method for Multivariate Calibration Model of Molecular Spectroscopy Analysis
CAO Yu-ting, YUAN Hong-fu, and ZHAO Zhong
Whether it is for near-infrared (NIR) spectra or mid-infrared (MIR) spectra, the issue of multivariate calibration model transfer between spectrometers has not been satisfactorily solved yet. To realize the sharing of model or spectra between the spectrometers, an improvedpiecewise direct standardization (PDS) method, Whether it is for near-infrared (NIR) spectra or mid-infrared (MIR) spectra, the issue of multivariate calibration model transfer between spectrometers has not been satisfactorily solved yet. To realize the sharing of model or spectra between the spectrometers, an improvedpiecewise direct standardization (PDS) method, Spectra-Angle-PDS (SA-PDS), is proposed in this work. Spectral angle (SA) measurement which can evaluate the similarity between spectra or the difference between the spectral vector and the shape of the spectral curve is used as a criterion for optimization of parameters of PDS. The model transfer no longer needs reference data so that the model transfer is not affected by the error of properties of validation samples and the model. The model transfer from master spectrometer to slave one or opposite on the contrary can be more easily realized with SA-PDS. The proposed spectra transfer method (SA-PDS) has been applied to predict the content of glycosides in tobacco and thecontent of wax in asphalt using NIR and MIR spectra respectively. The PDS method using RMSEP to select parameters has also been performed for comparative study of the proposed model transfer technique. For the spectra transfer from salve to master spectrometers of NIR, comparative experiment results have shown thatthe root-mean-square error of prediction (RMSEP)with the proposed SA-PDS method is reduced from 5.257 4 (before transfer) to 1.337 1 (after transfer), and much smaller than that with PDS method (1.350 3). For the spectra transfer from salve to master spectrometers of MIR, the precision of model transfer also improved significantly, accompanied by the reduction in RMSEP from 0.525 1 to 0.186 9, is proven to be better than that with PDS method (0.219 4). The satisfactory spectra transfer results with the proposed SA-PDS method from the master spectrometer to the slave spectrometer has also been verified..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 973 (2018)
Mapping Analysis of Heavy Metal Elements in Polluted Soils Using Laser-Induced Breakdown Spectroscopy
GU Yan-hong, ZHAO Nan-jing, MA Ming-jun, MENG De-shuo, JIA Yao, FANG Li, LIU Jian-guo, and LIU Wen-qing
Laser-induced breakdown spectroscopy (LIBS) has become a powerful technology for quantitative analysis of the toxic heavy metals in soils due to its excellent attributes of rapid analysis speed, simultaneous multi-element assay, and low-cost detection with slight sample preparation. In this work, LIBS was applied to anLaser-induced breakdown spectroscopy (LIBS) has become a powerful technology for quantitative analysis of the toxic heavy metals in soils due to its excellent attributes of rapid analysis speed, simultaneous multi-element assay, and low-cost detection with slight sample preparation. In this work, LIBS was applied to analyze the spatial concentration distribution of toxic heavy metals in soils around a smelter. The spectral lines of copper (Cu), lead (Pb) and chromium (Cr) were used to directly analyze the concentration distribution in soils around the smelter. The relevance between the spectral line intensities of Cr and the total concentrations detected by inductively coupled plasma optical emission spectrometry (ICP-OES) was poor. To improve the analysis accuracy, the calibration-free LIBS (CF-LIBS) method combined with Saha equation was used. Compared with the preliminary analysis result of spectral line intensities, the concentration ratios of Cr/Si obtained from CF-LIBS showed a good correlation with the total concentrations. Then, the map of the spatial relative concentration distribution of Cr superposed on the aerial view of the locations was established. Our results demonstrate that LIBS is an efficient rapid method for mapping the spatial contaminated distribution of heavy metal elements and giving us the clear direction to treat heavy metal pollution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 982 (2018)
The Interaction between Rolitetracycline and Human Serum Albumin Using Multi-Spectral Methods and Molecular Modeling
FANG Qing, DONG Cheng-yu, WANG Yu, and LIU Ying
The interaction between rolitetracycline (RTC) and human serum albumin (HSA) has been investigated by using multi-spectral methods and molecular modeling under physiological conditions. Fluorescence spectra results revealed the presence of static quenching mechanism in the binding of RTC to HSA. The binding constants wThe interaction between rolitetracycline (RTC) and human serum albumin (HSA) has been investigated by using multi-spectral methods and molecular modeling under physiological conditions. Fluorescence spectra results revealed the presence of static quenching mechanism in the binding of RTC to HSA. The binding constants were of K298 K=3.13×105 L·mol-1 and K310 K=0.70×105 L·mol-1, respectively. The numbers of binding site were 1.09 and 0.95 at two different temperatures. The thermodynamic parameters indicated that hydrogen bond and van der Waals force were the major driving forces for interaction between RTC and HSA. The binding distance of RTC to HSA was calculated to 2.59 nm based on fluorescence resonance energy transfer. UV-Vis absorption spectra and 3-D fluorescence demonstrated that the conformation and micro-environment of HSA were changed with the addition of RTC. FT-IR spectra was used to quantitatively calculate the alternations of secondary structure of HSA with the α-helices content reduction from 51.5% to 43.1%, increasing the content of β-sheet (30.3%～31.4%) and β-turn (15.6%～16.1%). According to molecular modeling studies and site marker competitive experiments, it indicated that RTC bound in the Sudlow’s drug binding site Ⅰ of HSA and the subdomain ⅡA where Lys195, Arg218 and Arg222 residues were located. The work is helpful to understand the interaction mechanism between RTC and HSA at molecular level..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 3, 990 (2018)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20