JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ruiyong Wang,Xiaohui Kang,Ruiqiang Wang,Rui Wang,Huanjing Dou,Jing Wu,Chuanjun Song,Junbiao Chang
The interactions between trypsin and caffeine/theophylline were investigated by fluorescence spectroscopy , UV–visible absorption spectroscopy , resonance light scattering and synchronous fluorescence spectroscopy under mimic physiological conditions . The results revealed that the fluorescence quenching of trypsin by caffeine and theophylline was the result of the formed complex of caffeine–trypsin and theophylline–trypsin. The binding constants and thermodynamic parameters at three different temperatures were obtained. The hydrophobic interaction was the predominant intermolecular forces to stabilize the complex. Results showed that caffeine was the stronger quencher and bound to trypsin with higher affinity than theophylline .
研究领域:
生物化学
·
分子药理学
·
药物代谢
·
蛋白质-配体相互作用
·
光谱学
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2016
·Vol. 127
·期 3
·1889-1895
·
IF 1.781
Yuan Kangkang,Gan Xinzhu,Wang Xinqiang,Zhu Luyi,Zhang Guanghui,Xu Dong
The present study fully reports the decomposition of polyacetylacetonatozirconium (PAZ) in air with thermogravimetry–differential scanning calorimetry and Fourier transform infrared spectroscopy. The influence of water vapor on the decomposition of PAZ was characterized with the Fourier transform infrared spectroscopy. Crystallization and phase transformation of PAZ were studied by X-ray diffraction and Raman spectroscopy. The experimental results show that water vapor promotes the decomposition of PAZ and crystallization of zirconia compared with air. Furthermore, the effect of different amount of stabilizer Y(NO 3 ) 3 ·6H 2 O on the pyrolysis and phase stabilization of PAZ shows that NO 3
− was beneficial to the oxidation of organic components and the formation of Y 2 O 3 could stabilize tetragonal zirconia and hinder grain growth.
研究领域:
材料化学
·
无机化学
·
纳米材料
·
热分析
·
光谱学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 2
·954-958
·
IF 2.562
Guihua Li,Xuzhong Cui,Cuiying Tan,Nan Lin
Uniform and polycrystalline tellurium nanoplates with a thickness of 100–300 nm can be rapidly synthesized by a simple solvothermal method in mixtures of water and ethanediamine at 180 °C with the assistance of glucose. By adjusting the concentration of glucose, tellurium microrods and nanoplates can be prepared. Based on the electron microscope observations, a possible mechanism involved the self-assembly process and dissolution–recrystallization mechanism is proposed for explaining the formation of polycrystalline tellurium nanoplates and their transformation into single crystalline nanorods. Furthermore, the Raman scattering measurement for the different morphologies is conducted, and the polycrystalline nanoplates present the stronger Raman scattering spectrum.
研究领域:
材料科学
·
纳米技术
·
无机化学
·
凝聚态物理
·
光谱学
✓ 已验证
DOI
高影响因子
POLYHEDRON
·
2016
·
IF 2.108
Tongguang Sun,Fei Liang,Xinyuan Zhang,Heng Tu,Zheshuai Lin,Guochun Zhang,Yicheng Wu
Single crystals of three new organic–inorganic hybrid compounds, tri[1-(diaminomethylene)uronium] hexachlorobismuthate ((C 2 H 7 N 4 S) 3 BiCl 6 ·H 2 O, HATU-BCH), bis[1-(diaminomethylene)uronium] pentabromobismuthate, ((C 2 H 7 N 4 S) 2 BiBr 5 , HATU-BB), and bis [3,5-diamino-1,2,4-thiadiazol-2-ium] pentaiodobismuthate ((C 2 H 5 N 4 S) 2 BiI 5 , OHATU-BI), have been successfully grown by slow evaporation method. Their structures were determined by single - crystal X-ray diffraction, in which all anion sublattice structures consist of hexahalobismuthates octahedra with different connection modes involving isolated, shared-corner, and shared-edge. The spectra characters were studied by Infrared and Raman spectra, which interpreted by calculation of the density functional theory (DFT) method and diffuse reflectance spectra. Thermal properties were characterized by thermal gravimetric analysis and differential scanning calorimetry.
研究领域:
材料化学
·
晶体工程
·
配位化学
·
光谱学
·
热分析
·
计算化学
✓ 已验证
DOI
高影响因子
Journal of Food Measurement and Characterization
·
2020
·Vol. 14
·期 5
·2549-2558
·
IF 1.648
Hu Jun,Liu Yande,He Yong,Sun Xudong,Li Bin
Food safety has been an issue of common concern in today’s society. Excessive benzoic acid (BA) additives in wheat flour would pose a huge threat to human health. In this paper, terahertz (THz) time-domain spectroscopy was used to detect BA quantitatively, which is a preservative additive in flour. Samples were prepared by grinding, drying, weighing, mixing and performing successively according to the designed concentration gradient (concentration 0.04%, 0.08%, 0.1%, 0.2%, 0.4%, 0.5%, 1%, 1.5%, …, 10%), with the BA concentration ranging from 0.040% to 19.99%. Then the THz Spectra of wheat flour samples with different concentrations of BA were collected. After preprocessing the original terahertz spectra with multiple scattering correction and other methods, Competitive Adaptive Reweighted Sampling (CARS), Genetic Algorithm (GA), Principal Component Analysis (PCA) and Uninformative Variable Elimination (UVE) were used to select effective spectral bands, and then Partial Least Squares (PLS) and Least Square Support Vector Machine (LS-SVM) models were established respectively. It turned out that the absorption peak of BA was at 1.94 THz of terahertz absorption coefficient, which increased with the rise of BA concentration. The results also indicated that better modeling results could be obtained by using CARS method for variable selection. And the established CARS-PCA-LS-SVM model had the best prediction result by combining PCA with CARS, with the correlation coefficient of the prediction (R p ) of 0.9956 and Root Mean Square Error of Prediction (RMSEP) of 0.64%. Hence, it can be concluded that terahertz technology combined with LS-SVM model can well achieve the quantitative detection of BA concentration in flour. Although the model is not universal since samples size is not large enough, the research method provides a basis for the detection of BA additives in flour.
研究领域:
食品科学
·
分析化学
·
光谱学
·
食品安全
·
计算生物学
·
分子检测技术
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2014
·
IF 1.716
J. Yuan,W.C. Wang,D.D. Chen,M.Y. Peng,Q.Y. Zhang,Z.H. Jiang
Enhanced 1.8 μm emission from Tm 3+ by Yb 3+ sensitization and bubbling in tungsten tellurite glasses has been demonstrated under the excitation of a 976 nm laser diode . Radiative properties such as spontaneous emission probabilities, radiative lifetimes and fluorescence branching ratios along with absorption and emission cross sections have been calculated from the absorption spectra . The influences of Yb 3+ concentration, Tm 3+ concentration, and bubbling time on spectroscopic properties have been thoroughly investigated. It is found that with increasing the bubbling time to 35 min, OH − content deceases sharply while 1.8 μm emission intensity improves greatly and 3 F 4 level lifetime prolongs to 1.57 ms close to radiative time. After 35 min, they change very little due to almost reaching the dynamic balance. The strength of interaction between Tm 3+ and OH − is determined. The energy transfer mechanism between Yb 3+ and Tm 3+ is proposed by photoemission spectroscopy and lifetime measurement. The energy transfer coefficients have been analyzed by the extended spectral overlap method and hopping model. Large ratio of the forward energy transfer from Yb 3+ to Tm 3+ to the backward one (223) and high energy transfer efficiency (97%) from Yb 3+ to Tm 3+ ensure efficient 1.8 μm emission. Hence, Yb 3+ sensitization and the reduction of OH − content could be expected to open up a possibility to achieve high efficient 2.0 μm lasing from Tm 3+ under a 976 nm LD pump.
研究领域:
光学材料
·
激光物理
·
固体激光器
·
光谱学
·
无机非金属材料
·
光子学
·
稀土发光材料
✓ 已验证
DOI
高影响因子
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
·
2023
·Vol. 65
·期 5
·1433-1438
·
IF 1.5
Qiu-Shi Liu,Ming-Jiang Ma,Chong Lv,Guo-Qing Yang,Yan-Lei Yang,Jia-Hao Wang,Zhi-Xing Gao,Hong-Yu He,Xiao-Hua Zhang,Yuan-Peng Li,Bao-Zhen Zhao
Spatially offset Raman spectroscopy (SORS) is an important branch derived from conventional Raman spectroscopy. It has the characteristics to realize the concealed component identification covered by opaque and translucent media nondestructively and rapidly. This technology gradually plays an important role in basic and applied research of numerous areas. This paper focuses on the SORS potential application in food quality and safety inspection, and a SORS detection system has been setup. The ingredients of various concealed food additives have been identified by SORS and the optimum offset distance for detection has been obtained. Meanwhile, the identification effectiveness of the system for low-concentration additives in real foods has also been evaluated.
研究领域:
分析化学
·
食品科学
·
光谱学
·
食品安全
·
质量控制
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 29
·19731-19737
·
IF 4.449
Yingna Cui,Jingmei Yin,Changping Li,Shenmin Li,Ailing Wang,Guang Yang,Yingping Jia
The compositions and structures of amine-based functionalized protic ionic liquids (PILs), namely N,N-dimethyl(cyanoethyl)ammonium propionate (DMCEAP) and N,N-dimethyl(hydroxyethyl)ammonium propionate (DMEOAP) have been investigated systematically by IR and 1H NMR spectroscopy and density functional theory (DFT) calculations. Analysis of the IR spectra suggests that both DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase, the former one mainly existing in the state of precursor molecules, and the latter mainly as ion-pairs. The ratio of precursor molecules to ion-pairs in the liquid phase depends on the types of precursors, especially the functional groups of cations. 1H NMR spectra indicate that there is a dynamic equilibrium between the neutral and ionized species, probably due to the formation of some intermediates in the PILs. The DFT calculations have been carried out to reveal the conformation, and obtain the corresponding IR and 1H NMR spectra of the neutral and ionized species, so that the theoretical support to the experimental results can be provided. The present study will help understand the properties of PILs and provide guidance for further applications of PILs.
研究领域:
物理化学
·
离子液体化学
·
光谱学
·
理论化学
·
分析化学
·
材料化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Yanqi Gu,Shayu Li,Yuehong Xu,Jiaguang Han,Miao Gu,Zhipeng Cai,Yan lv,Guoxin Xie,Tianbao Ma,Jianbin Luo
The influence of an external magnetic field on the picosecond network dynamics of the salt (KCl) solution is investigated by terahertz time-domain spectroscopy. Because hydration changes the motions of water molecules clusters, we test hydration by measuring the change of dielectric loss caused by the slow relaxation of water molecules clusters. We find experimentally that the magnetic field enhances the number of water molecules involved in hydration and the radius of dynamic hydration layer in salt solutions. However, with the increasing concentration, there is a downward in the hydration enhancement per equivalent. Meanwhile, the simulated results show the number of water molecules in hydration layers increases which is consistent with our experimental results. Besides, the simulation reveals that external magnetic field mainly affects the second hydration layer and the stability of water molecules network in hydration layer is enhanced with external magnetic field .
研究领域:
物理化学
·
生物物理
·
分子生物学
·
光谱学
·
溶液化学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
XiaoDan Zeng,Lin Zhu,FuSheng Zhang,LiYun Feng
The interaction of bovine serum with leucomalachite green (LMG) was investigated by spectroscopic methods . LMG was found to quench the intrinsic fluorescence of BSA by dynamic quenching. High quenching constant suggested that LMG can form a complex with BSA. Binding constant and number of binding site were determined. The thermodynamic parameters suggested the main interacting force is hydrophobic forces . The effect of LMG on the conformation of BSA was analyzed by synchronous fluorescence spectroscopy . RLS spectra were also used to reconfirm the formation of complex between BSA and LMG.
研究领域:
生物化学
·
分子生物学
·
光谱学
·
药物代谢
·
蛋白质-配体相互作用
✓ 已验证
DOI
高影响因子
RSC Advances
·
2011
·Vol. 2
·期 2
·583-589
·
IF 0
Jiali Lin,Qijun Wu,Gaiting Liang,Lily Zu,Weihai Fang
Cyclohexoxy and its methyl substituted variants play an important role in atmospheric chemistry. Direct spectral observation of these radicals can provide information about their structures and serve as convenient diagnostics for their monitoring. In this work, we report the first time observation of the LIF spectra of 2-, 3-, and 4-methylcyclohexoxy radicals in supersonic jet-cooled conditions. All spectra are consistent with a single conformer, and thermodynamic analysis of the conformers suggests that the conformer has the diequatorial (e, e) chair structure. Vibrational frequency analysis was performed using CASSCF/6-31+G(d) method on the state of radicals and the vibronic bands were assigned. The origin band of the methyl substituted cyclohexoxy shifted to red with the decrease of the separation distance between the methyl group and the oxygen atom on the ring. Different spectral character of 2-methylcyclohexoxy radical suggested that the neighboring methyl group affected the behavior of the radical on the excited state.
研究领域:
物理化学
·
光谱学
·
大气化学
·
自由基化学
✓ 已验证
DOI
Journal of Energy Chemistry
·
2020
·
IF 7.216
Chen Liang,Wenhua Zhang,Zesen Wei,Zhaoyu Wang,Qingsong Wang,Jinhua Sun
Based on the synchrotron soft X-ray absorption spectroscopy experiments, the fundamental electronic structures of layered LiNi x Co y Mn z O 2 (NCM) are investigated systematically and the data of transition-metal (TM) L - and O K -edges spectra are collected. Distribution of Ni ions under different oxidation states is evaluated according to linear combination fit. It is found that the ratio of Ni 4+ expands with the increase of Ni since it dominates in charge compensation during charging, and that the existence of Ni 3+ is nearly negligible in delithiated NCM. The valence state of Co also strongly depends on Ni content, the perceptible position shift of Co L 3 -edge absorption peak towards higher energy in Ni-rich material agrees well with the small voltage plateau at around 4.2 V. The stability of Mn is verified as no obvious spectral change with the Mn L -edge is observed. Moreover, as Ni content rises, the O 2 p holes near the Femi level increases with higher oxidation state of Ni, indicating the enhanced hybridization of O 2 p -TM 3 d . Delithiated NCMs with higher Ni content are prior to lose electron existing in highly hybridized Ni 3 d -O 2 p bands upon heating, which accounts for the pronounced O 2 release in phase transitions and the deterioration in thermal stability. These detailed observation of the electronic structure evolution is one of the key ingredients to improving the electrochemical and thermal performance of NCM.
研究领域:
材料科学
·
电化学
·
储能
·
光谱学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）