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Conformational Analysis of γ-Butyrolactones by Nuclear Magnetic Resonance Spectroscopy

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Chinese Chemical Letters 1997年第10期8卷 885-888页

作者： Fu An KANG and Cheng Lie YIN (department of chemistry beijing normal university , beijing 100875) beijing normal UNIV DEPT CHEMBEIJING 100875PEOPLES R CHINA

A series of trans-4, 5-disubstituted -γ-butyrolactones are found to assume two different envelope conformations by means of nuclear magnetic resonance spectroscopy.

关键词： Conformational Analysis of Butyrolactones by Nuclear Magnetic Resonance Spectroscopy

The Electrochemical Behavior of Bleomycin at A Co/GC Ion Implantation Modified Electrode

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Chinese Chemical Letters 1999年第10期10卷 855-856页

作者： Jing Bo HU Qi Long LI (department of chemistry, beijing normal university, beijing 100875) beijing normal Univ Dept Chem Beijing 100875 Peoples R China

In 0.10 mol/L HOAc-NaoAc buffer solution (pH 4.59). a sensitive reduction peak of bleomycin is obtained by linear sweep voltammetry at Co/GC ion implantation modified electrode. Its electrochemical behavior has been studied. The experiments of AES and XPS show that Co is surely implanted into the surface of GCE and improved the electrocatalytic activity.

关键词： ion implantation electrochemical behavior bleomycin

Asymmetric Photocatalyzed Addition of Cyclic Ammes to the Chiral 5-(l)-Menthyloxy-2(5H)-furanone

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Chinese Chemical Letters 1999年第11期10卷 889-892页

作者： Zhao Yang WANG Tian Ying JIAN qing Hua CHEN(department of chemistry,beijing normal university, beijing 100875) department of chemistry Beijing Normal University Beijing 100875 China

The benzophenone-initiated photoaddition of N-methyl ammes 2 to the chiral synthon1 proceeds in a regiospecitlc and highlyr stereocontrolled thshion to give the C-C photoadductscontaining a ne\viy stereogenic center 3a-3c. The enantiomerically pure N-C photoadducts, aminobutenolides 5a-5c have been obtained from the enantioselective photoaddition of secondary cyclicammes 4 with the chiral synthon 1 under the same conditions.

关键词： Asymmetric photocatalysed conjugate addition enantiomerically pure C-Cphotoadducts. secondary cyclic amine enantiomerically pure N-C photoaducts.

A Novel Synthesis of Isoxazole Derivatives

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Chinese Chemical Letters 1998年第9期9卷 801-802页

作者： Jun Feng WANG Bao Shan DU qing Hua CHEN (department of chemistry, beijing normal university, beijing 100875) beijing normal Univ Dept Chem Beijing 100875 Peoples R China

The new synthetic method of isoxazole derivatives was succesfully achieved. The experimental results demonstrate that thermal decomposition reactions of nitrone could take place with yields of 41 similar to 81%, to gi... 详细信息

关键词： nitrone isoxazole

Didodecyldimethylammonium Bromide Films Containing Cobalt Phthalocyanine Tetrasulfonate for Electrochemical Catalysis

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Chinese Chemical Letters 1999年第2期10卷 123-124页

作者： Nai Fei HU Rong HUANG Jing YANG (department of chemistry,beijing normal university, beijing 100875) beijing normal Univ Dept Chem Beijing 100875 Peoples R China

Electrochemistry of didodecyldimethylammonium (DDAB) films containing cobalt phthalocyanine tetrasulfonate (CoPcTS4-) was examined. CoPcTS4--DDAB film electrode showed stable cyclic voltammetric responses in buffers a... 详细信息

关键词： cobalt phthalocyanine tetrasulfonate didodecyldimethylammonium bromide electrochemical catalysis

Progress in the study of molecular organized assemblies by dielectric relaxation spectroscopy

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Progress in Natural Science:Materials International 2006年第3期16卷 221-230页

作者： ZHao Kongshuang, HE Kejuan and WEI Suxiang (department of chemistry, beijing normal university, beijing 100875, China department of chemistry, South China normal university, Guangzhou 510631, China) [a]department of chemistry Beijing Normal University Beijing China [b]department of chemistry South China Normal University Guangzhou China

Because dielectric spectroscopy covers a great many problems in physical and chemical systems occurring in an extremely wide frequency range, the study of this method plays an important role in physical chemistry. As an effective tool to detect inner properties of substance systems, the dielectric spectroscopy method is widely used in chemical systems and has been dramatically developed in recent decade. This review paper describes the applications of the dielectric spectroscopy in the chemical field, and main concentrations are focused on the micelle, microemulsion and other so-called molecular organized assemblies. Some dielectric principles and models proposed for these systems are introduced. In addition, recent technical developments in dielectric spectroscopy and developing trend of this method in other chemical systems are reviewed.

关键词： dielectric relaxation micelle microemulsion vesicle relaxation time.

SINGLE BIRTH PROCESSES

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Chinese Annals of Mathematics,Series B 1999年第1期20卷 77-82页

作者： CHEN MUFA(department of Mathematics,beijing normal university,beijing 100875,China) beijing normal Univ Dept Math Beijing 100875 Peoples R China

The single birth process is a Markov chain, either time-continuous or time-discrete, valuedin the non-negative integers: the system jumps with positive rate from k to k + 1 but not tok +j for all j 2 (this explains the meaning of 'single birth') . However, there is no restrictionfor the jumps from k to k - j(1 j< k). This note mainly deals with the uniqueness problemfor the time-continuous processes with an extension: the jumps from k to k + 1 may also beforbidden for at most finite number of k. In both cases (time-continuous or -discrete), thehitting probability and the first moment of the hitting time are also studied

关键词： Markov chains Single birth process Uniqueness criterion

Synthesis and Structural Characterization of One-dimensional Polynuclear Complex [La(bipyN_2O_2)(TFA)_3]_n

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Chinese Chemical Letters 2000年第10期11卷 935-936页

作者： Wen Xiang ZHU, Yun HE (department of chemistry, beijing normal university, beijing 100875) (department of Pharmacy, beijing Staff Medical College, beijing 100036) department of chemistry Beijing Normal University Beijing 100875 China department of Pharmacy Beijing Staff Medical College Beijing 100036 China

A novel polymeric complex [La(bipyN2O2)(TFA)3]n(TFA= trifluoroacetylacetone) was prepared. The X-ray structure analysis revealed that the complex has an infinite one-dimensional supramolecule structure with the 4,4'-bipyridyl-N,N'-dioxide as a bridge. La(III) is coordinated to eight oxygen atoms, six from three trifluoroacetylacetonate anions, two from two 4,4'-bipyridyl-N,N'-dioxide molecules.

关键词： Lanthanum polynuclear complex trifluoroacetylacetone 4,4'-bipyridyl-N,N'-dioxide.

Theoretical Study on the Pyrolysis Mechanism and Kinetics of 3-Hydroxy-3-Methyl-2-Butanone

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Chinese Chemical Letters 1998年第11期9卷 0-0页

作者： Wen Lin FENG Jie Hao CHEN Yan WANG (department of chemistry, beijing normal university, beijing 100875) beijing normal Univ Dept Chem Beijing 100875 Peoples R China

The mechanism and kinetics for the decomposition of 3-hydroxy-3-methyl-2-butanone have been studied by using the ab initio RHF/3-21G method. The calculated activation barrier of the reaction is 249.6kJ/mol which is in reasonable agreement with the experimental data (222.2±3kJ/mol). The calculated results show that the decomposition is a concerted process with hydrogen transferring and bond breaking via a five-membered cyclic transition state. The thermal rate constants of the decomposition are obtained by calculating microcanonical probability fluxes through transition state1.

关键词： Kinetics mechanism theoretical study rate constants