The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are a...The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.展开更多
Benzyl 4 amino 5 mercapto 1,2,4 triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e. , 3 benzyl 6 aryl 1,2,4 triazolothiadiazoles, each of which has ...Benzyl 4 amino 5 mercapto 1,2,4 triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e. , 3 benzyl 6 aryl 1,2,4 triazolothiadiazoles, each of which has an active methylene at 3 position. The structures of all the title compounds were confirmed by elementary analysis, IR, 1H NMR and 13 C NMR spectra.展开更多
The electronic structure of semiconductor materials governs the law of electron motion,which profoundly affects the properties such as conductivity and photoelectric conversion.Photo-responsive single-molecule junctio...The electronic structure of semiconductor materials governs the law of electron motion,which profoundly affects the properties such as conductivity and photoelectric conversion.Photo-responsive single-molecule junction technology provides insights into the electronic structure of photogenerated substances at the molecular scale,enabling the characterization of dynamic processes such as charge separation and energy transfer.These processes involve the unique quantum state known as the "exciton".The electrical characterization technique based on single molecule break junction facilities direct measurement of the photoelectric response of molecules at nanometer and subnanometer scale.This study reviews recent research progress of exciton effects and the characterization of optoelectronic phenomena.The mechanisms of exciton effects in three key optoelectronic phenomena—photoconductivity,photovoltaic s,and photoluminescence—are discussed.Furthermore,advanced spectral characterization techniques applied to the in-situ monitoring of single-molecule optoelectronic devices are highlighted.These include Raman spectroscopy with various enhancements,inelastic electron tunneling spectroscopy,and ultrafast spectroscopy with high resolution.展开更多
Tantalum(Ⅴ)propoxide(Ta(OPrn)5),isopropoxide(Ta(OPr i )5)and butoxide(Ta(OBu n )5)were synthesized by electro- chemical reactions of corresponding alcohol at sacrificial tantalum anode in the presence of tetraethylam...Tantalum(Ⅴ)propoxide(Ta(OPrn)5),isopropoxide(Ta(OPr i )5)and butoxide(Ta(OBu n )5)were synthesized by electro- chemical reactions of corresponding alcohol at sacrificial tantalum anode in the presence of tetraethylammonium chloride as a conductive additive.The pure products were isolated by reduced pressure distillation under 5 kPa.The crystal of Ta(OPri)5 was obtained by recrystallization from hexane at-10℃.These samples were characterized by Fourier transform infrared spectra(FT-IR), Raman spectra,nuclear magnetic resonance spectra(NMR),TG/DTA and ICP-MS.The results show that direct electrochemical synthesis of metal alkoxides has a high current efficiency and electrolysis yield.These alkoxides have a high purity of 99.97%and can be directly used as the precursor of Ta2O5 films.展开更多
From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a new minor ent-kaurane diterpene glycoside having five β-D-glucopyranosyl units has been isolated. The chemical structure of the new compound w...From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a new minor ent-kaurane diterpene glycoside having five β-D-glucopyranosyl units has been isolated. The chemical structure of the new compound was characterized as 13-[(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester (1) on the basis of extensive 1D (1H & 13C) and 2D NMR (TOCSY, HMQC, and HMBC), and High Resolution (HR) mass spectroscopic data as well as hydrolysis studies.展开更多
Rebaudioside D3, a novel steviol glycoside, is produced by specific UDP-glycosyltransferase of rebaudioside E, a minor steviol glycoside of Stevia rebaudiana Bertoni. The complete proton and carbon NMR spectral assign...Rebaudioside D3, a novel steviol glycoside, is produced by specific UDP-glycosyltransferase of rebaudioside E, a minor steviol glycoside of Stevia rebaudiana Bertoni. The complete proton and carbon NMR spectral assignments of rebaudioside D3, 13-[(2-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-β-D-glucopyranosyl) oxy] ent-kaur-16-en-19-oic acid-(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester, was achieved by the extensive 1D and 2D NMR (1H and 13C, TOCSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside D3 using acid and enzymatic studies to identify aglycone and sugar residues in its structure. Rebaudioside D3 is detected in the commercial extract of the leaves of Stevia rebaudiana by LC-MS analysis, suggesting rebaudioside D3 is a natural steviol glycoside.展开更多
A new mixed complex [Zn(tren) (H-SSA)] was synthesized based on the reaction of ZnO,5-sulfosalicylic acid and tren in water-methanol mixed solvents where tren was tris(2-aminoethyl)amine for the first time. The struct...A new mixed complex [Zn(tren) (H-SSA)] was synthesized based on the reaction of ZnO,5-sulfosalicylic acid and tren in water-methanol mixed solvents where tren was tris(2-aminoethyl)amine for the first time. The structure of the mixed complex was characterized by elemental analysis, IR, 1H NMR and thermal analysis. The crystal structure of the complex was also determined by X-ray single crystal diffraction. Its crystal belongs to trigonal system with space group P31, a=1.109 67(18) nm, b=1.109 67(18) nm, c=1.236 8(4) nm, V=1.318 9(5) nm3; Dc=1.616 g·cm-3; Z=3; F(000)=666; μ=1.553 mm-1. CCDC: 253908.展开更多
new coordination polymer {[Zn(CF3COO)2(C5H5ON)]·H2O}n was synthesized based on the reaction of zinc(Ⅱ) trifluoroacetate and 3-hydroxypyridine(C5H5ON) in methanol medium for the first time. The structure of the c...new coordination polymer {[Zn(CF3COO)2(C5H5ON)]·H2O}n was synthesized based on the reaction of zinc(Ⅱ) trifluoroacetate and 3-hydroxypyridine(C5H5ON) in methanol medium for the first time. The structure of the coordination polymer was confirmed by IR, 1H NMR, elemental analysis and thermal analysis. The crystal structure of the coordination polymer was also determined by X-ray single crystal diffraction. The crystal belongs to monoclinic system with space group P21/m, and crystallographic data of the coordination polymer are: a= 0.863 1(4) nm, b=0.717 7(3) nm, c=1.116 4(5) nm, α=γ=90°, β=107.542(6)°, V=0.659 4(5) nm3; Dc=2.037 g·cm-3; Z=2; F(000)=400; μ=1.969 mm-1. Zinc(Ⅱ) atom lies at the center of an octahedron formed by the coordination of zinc atom and six O atoms which come from four different trifluoroacetate ions and two different 3-hydroxypyridine molecules where each trifluoroacetate ion and 3-hydroxypyridine are coordinated to two different zinc ions to form coordination polymer. CCDC: 253909.展开更多
文摘The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.
基金Supported by the National Natural Science Foundation of Chinathe University Backbone Teachers Foundation of theEducation Ministry of Chinaand Zhejiang Province Education Department
文摘Benzyl 4 amino 5 mercapto 1,2,4 triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e. , 3 benzyl 6 aryl 1,2,4 triazolothiadiazoles, each of which has an active methylene at 3 position. The structures of all the title compounds were confirmed by elementary analysis, IR, 1H NMR and 13 C NMR spectra.
基金Supported by the National Natural Science Foundation of China (Grant No. 10961023)National Natural Science Foundation of China for Young Scholars (Grant No. 11101232)+1 种基金Natural Science Foundation of Qinghai Province for Young Scholars (Grant No. 2011-Z-929Q)Scientific Research Innovation Program of Qinghai Normal University
文摘In the paper, we prove that all generalized cocktail-party graphs with order at least 23 are determined by their adjacency spectra.
基金financially supported by the Program of Higher-Level Talents of IMU(No.21300-5223748)the National Natural Science Foundation of China(Nos.22103065 and 21661024)
文摘The electronic structure of semiconductor materials governs the law of electron motion,which profoundly affects the properties such as conductivity and photoelectric conversion.Photo-responsive single-molecule junction technology provides insights into the electronic structure of photogenerated substances at the molecular scale,enabling the characterization of dynamic processes such as charge separation and energy transfer.These processes involve the unique quantum state known as the "exciton".The electrical characterization technique based on single molecule break junction facilities direct measurement of the photoelectric response of molecules at nanometer and subnanometer scale.This study reviews recent research progress of exciton effects and the characterization of optoelectronic phenomena.The mechanisms of exciton effects in three key optoelectronic phenomena—photoconductivity,photovoltaic s,and photoluminescence—are discussed.Furthermore,advanced spectral characterization techniques applied to the in-situ monitoring of single-molecule optoelectronic devices are highlighted.These include Raman spectroscopy with various enhancements,inelastic electron tunneling spectroscopy,and ultrafast spectroscopy with high resolution.
基金Project(2007AA03Z425)supported by the Hi-tech Research and Development Program of ChinaProject(50404011)supported by the National Natural Science Foundation of China
文摘Tantalum(Ⅴ)propoxide(Ta(OPrn)5),isopropoxide(Ta(OPr i )5)and butoxide(Ta(OBu n )5)were synthesized by electro- chemical reactions of corresponding alcohol at sacrificial tantalum anode in the presence of tetraethylammonium chloride as a conductive additive.The pure products were isolated by reduced pressure distillation under 5 kPa.The crystal of Ta(OPri)5 was obtained by recrystallization from hexane at-10℃.These samples were characterized by Fourier transform infrared spectra(FT-IR), Raman spectra,nuclear magnetic resonance spectra(NMR),TG/DTA and ICP-MS.The results show that direct electrochemical synthesis of metal alkoxides has a high current efficiency and electrolysis yield.These alkoxides have a high purity of 99.97%and can be directly used as the precursor of Ta2O5 films.
文摘From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a new minor ent-kaurane diterpene glycoside having five β-D-glucopyranosyl units has been isolated. The chemical structure of the new compound was characterized as 13-[(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester (1) on the basis of extensive 1D (1H & 13C) and 2D NMR (TOCSY, HMQC, and HMBC), and High Resolution (HR) mass spectroscopic data as well as hydrolysis studies.
文摘Rebaudioside D3, a novel steviol glycoside, is produced by specific UDP-glycosyltransferase of rebaudioside E, a minor steviol glycoside of Stevia rebaudiana Bertoni. The complete proton and carbon NMR spectral assignments of rebaudioside D3, 13-[(2-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-β-D-glucopyranosyl) oxy] ent-kaur-16-en-19-oic acid-(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester, was achieved by the extensive 1D and 2D NMR (1H and 13C, TOCSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside D3 using acid and enzymatic studies to identify aglycone and sugar residues in its structure. Rebaudioside D3 is detected in the commercial extract of the leaves of Stevia rebaudiana by LC-MS analysis, suggesting rebaudioside D3 is a natural steviol glycoside.
文摘A new mixed complex [Zn(tren) (H-SSA)] was synthesized based on the reaction of ZnO,5-sulfosalicylic acid and tren in water-methanol mixed solvents where tren was tris(2-aminoethyl)amine for the first time. The structure of the mixed complex was characterized by elemental analysis, IR, 1H NMR and thermal analysis. The crystal structure of the complex was also determined by X-ray single crystal diffraction. Its crystal belongs to trigonal system with space group P31, a=1.109 67(18) nm, b=1.109 67(18) nm, c=1.236 8(4) nm, V=1.318 9(5) nm3; Dc=1.616 g·cm-3; Z=3; F(000)=666; μ=1.553 mm-1. CCDC: 253908.
文摘new coordination polymer {[Zn(CF3COO)2(C5H5ON)]·H2O}n was synthesized based on the reaction of zinc(Ⅱ) trifluoroacetate and 3-hydroxypyridine(C5H5ON) in methanol medium for the first time. The structure of the coordination polymer was confirmed by IR, 1H NMR, elemental analysis and thermal analysis. The crystal structure of the coordination polymer was also determined by X-ray single crystal diffraction. The crystal belongs to monoclinic system with space group P21/m, and crystallographic data of the coordination polymer are: a= 0.863 1(4) nm, b=0.717 7(3) nm, c=1.116 4(5) nm, α=γ=90°, β=107.542(6)°, V=0.659 4(5) nm3; Dc=2.037 g·cm-3; Z=2; F(000)=400; μ=1.969 mm-1. Zinc(Ⅱ) atom lies at the center of an octahedron formed by the coordination of zinc atom and six O atoms which come from four different trifluoroacetate ions and two different 3-hydroxypyridine molecules where each trifluoroacetate ion and 3-hydroxypyridine are coordinated to two different zinc ions to form coordination polymer. CCDC: 253909.
