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561.
Wei WANG Guang Ming XIA Gui Bao XU Zhi Qiang LIU Qi FANG* State Key Laboratory of Crystal Materials Shandong University Jinan School of Chemistry Chemical Engineering Jinan University Jinan 《中国化学快报》2005,16(1):85-88
Organic molecules that can simultaneously absorb two or more photons in reaching theirexcited states have recently been the subject in various photon-electronic fields. Tomeet the criteria for various nonlinear optical applications, such as three-dimensionaloptical storage1 and up-converted lasing2, molecules with large two-photon absorption(TPA) cross-section σ are required and have been synthesized. These dyes generallybelong to the structural modes of D-π-D, A-π-A3 or D-π-A, where D… 相似文献
562.
The Existence and Long-Time Behavior of Weak Solution to Bipolar Quantum Drift-Diffusion Model 总被引:1,自引:0,他引:1 下载免费PDF全文
Xiuqing CHEN~* Li CHEN~ 《数学年刊B辑(英文版)》2007,28(6):651-664
The authors study the existence and long-time behavior of weak solutions to the bipolar transient quantum drift-diffusion model,a fourth order parabolic system.Using semi-discretization in time and entropy estimate,the authors get the global existence of nonnegative weak solutions to the one-dimensional model with nonnegative initial and homogenous Neumann(or periodic)boundary conditions.Furthermore,by a logarithmic Sobolev inequality,it is proved that the periodic weak solution exponentially approaches its mean value as time increases to infinity. 相似文献
563.
Yan Jing SU Xiong Hui WEI* Department of Applied Chemistry College of Chemistry Molecular Engineering Peking University Beijing 《中国化学快报》2006,17(5):691-694
Several benzo[c]phenanthridine alkaloids (BPA) were found in plants of Caprifoliaceae, Fumariaceae, Meliaceae, Papaveraceae, and Ruracea families1. BPA represent a group of natural products, exhibiting multiple pharmacological properties and biological ac… 相似文献
564.
Chao Zhan WANG Jiang Feng LIU Xin Du GENG* Institute of Modern Separation Science Key Laboratory of Separation Science in Shanxi Province Northwest University Xi''''an 《中国化学快报》2005,16(3):389-392
Human granulocyte colony-stimulating factor (hG-CSF), a single chain polypeptidecontaining 174 amino acid residues (MW=18,800, pI=6.1), is one of the hemopoieticgrowth factors which plays an important role in stimulating proliferation, differentiation,and functional activation of bloodcells1. It contains a free cysteine at position 17 andtwo intramolecular disulfide bonds, Cys36-Cys42 and Cys64-Cys74, and the two disulfidebonds in G-CSF molecule are both required for its bioactivity2. Wh… 相似文献
565.
Ying Hong WANG Kai Sheng HUANG Mao LIN* Institute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College Beijing 《中国化学快报》2000,11(12)
Continuous investigation on oligostilbenes from the lianas of Gnetum hainanense resulted in the isolation of a new rhapontigenin dimer, Gnetuhainin P (1), in addition to the dimers of resveratrol and oxyresveratrol reported previously1. Gnetuhainin P (1) was obtained as a yellowish amorphous powder, [(]25D +6.6 (c 0.092, MeOH). The high resolution FABMS m/z 533.1866 [M+H]+ gave a molecular formula of C30H28O9 (C30H29O9 requires 533.1812), which corresponds to a isorhapontigenin dimer. … 相似文献
566.
Peng DIAO Min GUO Ru Ting TONG* Department of Chemistry Hebei Teacher''''s University Shijiazhuang Department of Traditional Chinese Pharmacy Traditional Chinese Medicine College Hebei Medical University Shijiazhuang 《中国化学快报》2000,11(12)
Interest in the properties of organized monolayers has grown enormously in recent years because these monolayers can provide a means to control the interface at a molecular level1. The self-assemblies of alkanethiols and their derivatives were probably the most intensively studied due to their stability, well-packed structure, ease in preparation, and flexibility in designing the tail group2. The adsorption kinetics of thiol monolayer has been studied by using several techniques, including con… 相似文献
567.
Xiao Mei WANG Qi FANG Chun WANG Guang Yong ZHOU Yan REN Min Hua JIANG* State key laboratory of Crystal Materials Shandong University Jinan 《中国化学快报》2001,(1)
Two-photon absorption (TPA) occurs through the simultaneous absorption of two photons via virtual states in a medium. Materials with large TPA cross section are gaining increasing attention recently due to their potential applications in optical data storage, two-photon up-converted lasing, two-photon-laser scanning fluorescence microscopy, optical power limiting and photodynamic therapy1-3. Numerous organic compounds have been investigated both experimentally and theoretically in order to u… 相似文献
568.
Ya Ping WANG Lu Ling WU Xiang HUANG* College of Chemical Engineering Zhejiang University of Technology Hangzhou Department of Chemistry Zhejiang University Xixi Campus Hangzhou 《中国化学快报》2001,(1)
Conjugated dienes are valuable intermediates in organic chemistry. Many biologically active compounds occurring in nature possess the structural skeleton of conjugated dienes such as chillea amide1 and pelltoine2. Besides, the synthesis of conjugated dienes for use in the Diels-Alder reaction is still an important challenge in organic synthesis. One particularly attractive approach has been the incorporation of heteroatom substituents that can activate the diene3.Recently, we found that β-br… 相似文献
569.
Ke Chun ZHANG Lei LIU Ting Wei MU Qing Xiang GUO* Department of Chemistry University of Science Technology of China Hefei 《中国化学快报》2000,11(11)
The molecular recognition of cyclobis(paraquat-p-phenylene), 14+, has drawn great attention recently, due to its important applications in the design and synthesis of electrochemically and chemically switchable rotaxanes, photoactive rotaxanes, and other molecular devices1. Usually, this type of molecular recognition was investigated with the methods including X-ray, NMR, UV, and IR. However, since these methods usually have difficulties in providing a detailed understanding of the energeti… 相似文献
570.
Li Qiao Yu Zhi Zhou Huan Chen Jia Qing Cao Yue Hu Pei~* School of Traditional Chinese Materia Medica Shenyang Pharmaceutical University Shenyang China 《中国化学快报》2008,19(3):299-301
Cunninghamella elegans has been employed for the biotransformation of cinobufagin (1) to afford one metabolites. The structure of the transformation product has been characterized as 7β,12β-dihydroxylcinobufagin (2). Product 2 is a new compound. In vitro cytotoxic activities of the biotransformation product and the substrate-cinobufagin have been assayed against HeLa; they all showed cytotoxic activities. 相似文献