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561.
甲醇是一个重要的平台分子, 实现其高效转化为能源和化学品的关键是揭示相关反应过程中催化剂的结构与催化性能之间的关系和反应机理. 围绕这个关键问题, 以甲醇选择氧化为探针反应, 本文总结了负载氧化钼、负载氧化钒和杂多酸等典型催化剂体系以及近年来发展的氧化铼、氧化钌等新催化剂体系在认识催化活性中心结构和反应机理, 进而调控它们的氧化中心和酸中心等方面所取得的进展. 这些认识将有助于设计制备性能优异的新催化剂和实现甲醇到目标氧化产物的定向转化. 相似文献
562.
本文以钛酸正丁酯为前驱物、乙醇作为分散剂、二乙醇胺作为螯合剂、聚乙二醇作为表面活性剂,采用溶胶-凝胶法制备得到一种TiO2溶胶,并通过乙酸或氨水作用后制得另外两种溶胶,分别在室温于ITO导电玻璃上涂制,得到5种单一粒径范围纳米TiO2薄膜和具有两种粒径范围膜层的6种纳米TiO2薄膜;XRD和SEM等测试结果表明,纳米TiO2薄膜为锐钛矿相或锐钛矿与金红石相的混合相,其粒径分布范围在15~30nm,30~50 nm,40~80 nm区间。采用浸渍法将所制备的膜进行染料的敏化,得到染料敏化纳米TiO2薄膜半导体光阳极,测试结果表明,在所制备的纳米TiO2薄膜中,具有两种粒径范围膜层的纳米TiO2薄膜的光电性能相对较好。 相似文献
564.
Chun YANG * Key Lab of New Materials Technology of China National Packaging Corporation Zhuzhou Engineering College Zhuzhou College of Chemistry Environmental Science Nanjing Normal University Nanjing 《中国化学快报》2003,14(1):96-99
Recently, a novel method of modification, i.e., functionalizing the internal surface of mesoporous materials has been reported1-5, owing to the large pore size, the silanol groups, which are in a big population in mesoporous materials, can chemically couple with the active groups of some bulky organic functional molecules. Based on this approach, one can obtain novel solid basic catalysts. Here we functionalized the hexagonal and hexagonal-like mesoporous silica materials SBA-3 and HMS wi… 相似文献
565.
IntroductionFunctional polymers bearing chiral moietiesand the extended conjugatedπ system have attract-ed considerable attention during the pastdecade[1,2 ] .The enantiodifferation properties ofsuch macromolecules give rise to multiple applica-tions in the fields of asymmetric catalysis,chiralsensors,polarized light emission and nonlinear op-tical materials[3 ,4] .Especially the incorporation ofoptically active binaphthyls in the main chain ofconjugated polymers can lead to an efficient ands… 相似文献
566.
§1.IntroductionIn[5],MaliavinandNualartdefinedthenotionof(real)smoothmartingalesandwethenprovedin[6]thattheprocesofquasisureq... 相似文献
567.
Jin Wen WANG Yi Yuan PENG Cheng Xue ZHAO* Department of Chemistry Shanghai Jiaotong University Shanghai Department of Chemistry Jiangxi Normal University Nanchang 《中国化学快报》2002,13(8)
Because the solvent dependency of aN, g factors and line widths of some bulky and stable di-t-alkyl nitroxides1, ESR has been proved to be a useful tool in searching for the nature of medium effects ( solvation ) to chemical reactivity. A large number of fluorinated nitroxides with a wide variety of structures have been generated and subjected to extensive studies in our laboratory2. Amongst, t-butyl perfluoroalkyl nitroxides, much less hindered, with noβ-H atoms, have been employed as sp… 相似文献
568.
Jiu Yu LIU Hui Yuan GUO* Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences Peking Union Medical College Beijing 《中国化学快报》2004,15(5)
Quinolone antibacterial agents have emerged as one of the dominant classes chemotherapeutic drugs for the treatment of various bacterial infections1. We have focused our attention on the modification of the C-7 basic group of the quinolone which has been most varied. In 1987, Uno et al.2 reported that 3-hydroxypyrrolidine quinolones showed more active antibacterial activities than Norfloxacin in vivo. In 1998, Fujita et al.3 reported that 2-aminomethylpyrrolidine quinolones have the same … 相似文献
569.
Ke Qiang DING Zhen Bin JIA Qing Fei WANG Juan BAI Ru Ting TONG Xin Kui WANG Hui Bo SHAO* Institute of Coal Chemistry Chinese Academy of Science Taiyuan Department of Chemistry Hebei Teachers University Shijiazhuang D 《中国化学快报》2002,13(4)
Recently, the adsorption behavior of protein on solid substrate has attracted much attention for the reason that adsorption on a substrate is the first key step for other further electrochemical investigation1. Meanwhile the free adsorption could provide a relative well-ordered structure, with which some fundamental study could be carried out conveniently2. As we know, the electrochemical impedance spectroscopy (EIS) method has become one of the powerful techniques to detect the change of i… 相似文献
570.
Lanthanum doped lead zirconate titanate (PLZT) ceramics display excellent electrooptic and photostriction properties because of the existence of cavities in the perovskite structure1-3. The PLZT powders are conventionally prepared by solid state reaction4-5, and the wet chemical methods such as sol-gel techniques are then introduced6-7. However, the homogeneity, morphology and size of the particles, which greatly affect the sinterability and the property of the resulting ceramics, are dif… 相似文献