A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system...A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system, space group C2/m with a=19.1921（5）, b=18.6931（6）, c=9.3821（3） A° β=104.8020（11）°, V=3254.22（17）A°^3 C50H51Mo8N10NaO30, Mr=2062.52, Z=2, F（000）=2016, μ=1.591 mm^-1 and Dc=2.105 g/cm^3. The final R=0.0283 and wR=0.0912 for 3118 observed reflections （I〉20（I））. Compound 1 contains the β-[Mo8O26]^4-anion, sodium ion, 4,4＇-bpy and lattice crystalline water molecules. The β-[MosO26] units link the sodium ion to form a chain structure. The infinitechains of [Na（Mo8O26）]^3- blocks are surrounded by protonized 4,4＇-bpy cations, 4,4＇-bpy and lattice crystalline water molecules. The 2D-IR correlation spectroscopy study indicates that the stretching vibrations of Mo=O occur more preferentially due to the thermal effect. The TGA analysis shows that compound 1 has high thermal stability.展开更多
A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensi...A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensional(PCMW2D)and two-dimensional correlation(2DCOS)analyses were applied to the amideⅠband and thus the hydrogen bond interaction between SPI and Gly was systematically investigated.When Gly concentrations were in the range 0~35%,the hydrogen bond amongβ-sheets was replaced by the one between SPI chain and Gly molecule,which caused these protein chains being changed toα-helix.However,the transformation ofβ-sheet toα-helix was saturated and both of them tend to change to random coil when Gly concentrations were in the range 35%~60%.展开更多
Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors ha...Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors have begun to appear in the market. Therefore, it is an urgent need for new techniques to discriminate the genuine and counterfeit Moutai liquor. In this work, the conventional Ultraviolet-Visible (UV-Vis) spectroscopy and two-dimensional correlation UV-Vis spectroscopy are applied to obtain the UV-Vis characteristic of Moutai liquor and counterfeit one, respectively. The experimental results reveal that the conventional UV-Vis spectra of the genuine and counterfeit Moutai liquor are similar. However, the two-dimensional correlation UV-Vis spectra of them are different and this method would be applied to differentiate the counterfeit Moutai liquor from the genuine Moutai liquor. Compared with conventional methods, this novel method has the advantages of easy operation, simple instrumentation and direct recognition, which make it a potential tool in the fields of food safety.展开更多
The characteristics of effluent organic matter(EfOM) from a wastewater treatment plant(WWTP) during ozonation were investigated using excitation and emission matrix(EEM)spectra, Fourier transform infrared spectroscopy...The characteristics of effluent organic matter(EfOM) from a wastewater treatment plant(WWTP) during ozonation were investigated using excitation and emission matrix(EEM)spectra, Fourier transform infrared spectroscopy(FT-IR) and high-performance size exclusion chromatography(HPSEC) at different ozone dosages. The selectivity of ozonation towards different constituents and functional groups was analysed using two-dimensional correlation spectra(2D-COS) probed by FT-IR, synchronous fluorescence spectra and HPSEC.The results indicated that ozonation can destroy aromatic structures of EfOM and change its molecular weight distribution(MWD). According to 2D-COS analysis, microbial humiclike substances were preferentially removed, and then the protein-like fractions. Terrestrial humic-like components exhibited inactivity towards ozonation compared with the above two fractions. Protein-like substances with small molecular weight were preferentially reacted during ozonation based on 2D-COS probed by HPSEC. In addition, the selectivity of ozone towards different functional groups of EfOM exhibited the following sequence:phenolic and alcoholic C\O groups > aromatic structures containing C_C double bonds >aliphatic C\H. X-ray photoelectron spectroscopy(XPS) further elucidated the preferential reaction of aromatic structures in EfOM during ozonation.展开更多
We herein review our studies on simulating the thermal unfolding Fourier transform infrared and two-dimensional infrared spectra of peptides. The peptide-water configuration ensembles, required forspectrum modeling, a...We herein review our studies on simulating the thermal unfolding Fourier transform infrared and two-dimensional infrared spectra of peptides. The peptide-water configuration ensembles, required forspectrum modeling, aregenerated at a series of temperatures using the GBOBC implicit solvent model and the integrated tempering sampling technique. The fluctuating vibrational Hamiltonians of the amide I vibrational band are constructed using the Frenkel exciton model. The signals are calculated using nonlinear exciton propagation. The simulated spectral features such as the intensity and ellipticity are consistent with the experimental observations. Comparing the signals for two beta-hairpin polypeptides with similar structures suggests that this technique is sensitive to peptide foldinz landscapes.展开更多
基金This work was supported by the Foundation of Education Committee of Fujian Province (K02028, JB04049), the State Key Laboratory of Structural Chemistry, and Science and Technology Foundation of Fuzhou University
文摘A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system, space group C2/m with a=19.1921（5）, b=18.6931（6）, c=9.3821（3） A° β=104.8020（11）°, V=3254.22（17）A°^3 C50H51Mo8N10NaO30, Mr=2062.52, Z=2, F（000）=2016, μ=1.591 mm^-1 and Dc=2.105 g/cm^3. The final R=0.0283 and wR=0.0912 for 3118 observed reflections （I〉20（I））. Compound 1 contains the β-[Mo8O26]^4-anion, sodium ion, 4,4＇-bpy and lattice crystalline water molecules. The β-[MosO26] units link the sodium ion to form a chain structure. The infinitechains of [Na（Mo8O26）]^3- blocks are surrounded by protonized 4,4＇-bpy cations, 4,4＇-bpy and lattice crystalline water molecules. The 2D-IR correlation spectroscopy study indicates that the stretching vibrations of Mo=O occur more preferentially due to the thermal effect. The TGA analysis shows that compound 1 has high thermal stability.
文摘A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensional(PCMW2D)and two-dimensional correlation(2DCOS)analyses were applied to the amideⅠband and thus the hydrogen bond interaction between SPI and Gly was systematically investigated.When Gly concentrations were in the range 0~35%,the hydrogen bond amongβ-sheets was replaced by the one between SPI chain and Gly molecule,which caused these protein chains being changed toα-helix.However,the transformation ofβ-sheet toα-helix was saturated and both of them tend to change to random coil when Gly concentrations were in the range 35%~60%.
文摘Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors have begun to appear in the market. Therefore, it is an urgent need for new techniques to discriminate the genuine and counterfeit Moutai liquor. In this work, the conventional Ultraviolet-Visible (UV-Vis) spectroscopy and two-dimensional correlation UV-Vis spectroscopy are applied to obtain the UV-Vis characteristic of Moutai liquor and counterfeit one, respectively. The experimental results reveal that the conventional UV-Vis spectra of the genuine and counterfeit Moutai liquor are similar. However, the two-dimensional correlation UV-Vis spectra of them are different and this method would be applied to differentiate the counterfeit Moutai liquor from the genuine Moutai liquor. Compared with conventional methods, this novel method has the advantages of easy operation, simple instrumentation and direct recognition, which make it a potential tool in the fields of food safety.
基金supported by the National Key Technology Support Program (No.2014BAC13B06)the National Natural Science Foundation of China (Nos.51708443,51378414)+2 种基金the National Key Research and Development Program of China (No.2016YFC0400701)the China Postdoctoral Science Foundation (No.2017M623326XB)the Program for Innovative Research Teams in Shaanxi (No.2013KCT-13)
文摘The characteristics of effluent organic matter(EfOM) from a wastewater treatment plant(WWTP) during ozonation were investigated using excitation and emission matrix(EEM)spectra, Fourier transform infrared spectroscopy(FT-IR) and high-performance size exclusion chromatography(HPSEC) at different ozone dosages. The selectivity of ozonation towards different constituents and functional groups was analysed using two-dimensional correlation spectra(2D-COS) probed by FT-IR, synchronous fluorescence spectra and HPSEC.The results indicated that ozonation can destroy aromatic structures of EfOM and change its molecular weight distribution(MWD). According to 2D-COS analysis, microbial humiclike substances were preferentially removed, and then the protein-like fractions. Terrestrial humic-like components exhibited inactivity towards ozonation compared with the above two fractions. Protein-like substances with small molecular weight were preferentially reacted during ozonation based on 2D-COS probed by HPSEC. In addition, the selectivity of ozone towards different functional groups of EfOM exhibited the following sequence:phenolic and alcoholic C\O groups > aromatic structures containing C_C double bonds >aliphatic C\H. X-ray photoelectron spectroscopy(XPS) further elucidated the preferential reaction of aromatic structures in EfOM during ozonation.
基金supported by the National Natural Science Foundation of China(Grant No.21203178)the National Natural Science Foundation of China(Grant No.21373201)+2 种基金the National Natural Science Foundation of China(Grant No.21433014)the Science and Technological Ministry of China(Grant No.2011YQ09000505)“Strategic Priority Research Program”of the Chinese Academy of Sciences(Grant Nos.XDB10040304 and XDB100202002)
文摘We herein review our studies on simulating the thermal unfolding Fourier transform infrared and two-dimensional infrared spectra of peptides. The peptide-water configuration ensembles, required forspectrum modeling, aregenerated at a series of temperatures using the GBOBC implicit solvent model and the integrated tempering sampling technique. The fluctuating vibrational Hamiltonians of the amide I vibrational band are constructed using the Frenkel exciton model. The signals are calculated using nonlinear exciton propagation. The simulated spectral features such as the intensity and ellipticity are consistent with the experimental observations. Comparing the signals for two beta-hairpin polypeptides with similar structures suggests that this technique is sensitive to peptide foldinz landscapes.
