钒钼复合氧化物表面上激光促进异丁烷选择氧化制甲基丙烯酸

表面反应;钒钼复合氧化物表面上激光促进异丁烷选择氧化制甲基丙烯酸     

四(对-十二酰氧基苯基)卟啉配合物的红外光声光谱

四(对-十二酰氧基苯基)卟啉配合物的红外光声光谱     

5,10,15,20-四(对-癸酰氧基苯基)卟啉过渡金属配合物的合成与表征

液晶;5;10;15;20-四(对-癸酰氧基苯基)卟啉过渡金属配合物的合成与表征     

硒的分析方法及进展

就国内近年来对于中草药、食品、血清等样品中硒元素的分析方法研究进展进行了综述,主要有原子吸收法、等离子体发射光谱法,荧光法、分光光度法和电化学方法。     

反气相色谱法测定苯乙烯-氧乙烯-苯乙烯三嵌段聚合物的表面能

 采用反气相色谱法测定了苯乙烯 氧乙烯 苯乙烯三嵌段聚合物 (PS PEO PS)的色散成分的表面能 (γsd) ,研究探讨了温度及嵌段聚合物链段结构组成对γsd 的影响 ,并确定了γsd 与温度的数学关系式。研究结果表明 :在 70℃～ 12 0℃范围内 ,PS PEO PS的表面能较低 ;随着PS PEO PS表面组成中氧乙烯 (EO)成分的增加 ,色散成分的γsd 增大 ,且对温度的变化极其敏感 :随温度的升高 ,γsd 急剧地呈线性下降。     

激光促进甲醇在杂多化合物上的表面反应

利用红外光谱 (IR)、程序升温脱附 (TPD)和激光促进表面反应 (L SSR)技术 ,研究了甲醇吸附于杂多化合物 H3PMo1 2 O40 · x H2 O、H3PW1 2 O40 · x H2 O、H6 PMo6 W6 O40 · x H2 O表面上所形成体系的振动结构、化学吸附形态和光促表面反应规律 .实验结果表明 ,在各固体材料表面上甲醇同时发生分子吸附和解离吸附 ,且在室温条件下体系即发生显著的光促表面反应 ;与甲醇吸附强度和吸附量相比 ,反应体系的振动结构对 L SSR效率起着更重要的作用 .根据表征和反应结果 ,分析了体系中活性物种的产生途径 ,并给出了反应机理的模型     

Preparation and Molecular Structure of Binuclear Nickel (I) Complex Bridged by 1,2,4, 5‐Benzenetetracarboxylato Tetravalent Anion

The title complex [(H₂O)₂(IMI)₃Ni(TCB)Ni(IMI)₃‐(H₂O)₂] H₂O (TCB = 1,2,4,5‐benzenetetracarboxylato te‐travalent anion; IMI = imidazole) has been prepared by the reaction of Ni(IMI)₃(Ac)₂ and TCB in aqueous solution. The crystal structure has been determined by single‐crystal X‐ray diffraction method. It crystallizes in the monoclinic system, space group P2₁/c(# 14), a = 1.2714(4) nm, b = 0.9411 (3) nm, c = 1.5869(4) nm, β= 108.54(2)°, V= 1.8001(9) nm³, Z = 2. The main feature of the crystal structure is a symmetric binuclear unit made up of two slightly distorted coordination octahedrons, which are bridged by TCB in monodentate fashion to each metal ion. Moreover three nitrogen atoms from three imidazoles, three oxygen atoms from two water molecules and one carboxylate group of TCB coordinated to a nickel (I) ion are found on a face of the octahedron respectively, so the octahedron is a facial isomer.     

Multicanonical parallel simulations of proteins with continuous potentials

The determination of the three‐dimensional (3D) structure of a protein or peptide is a very important research problem in biological and medical sciences. Anfinsen's experiments (Science 1973, 181, 223) on renaturation of denatured proteins have shown that the native 3D structure of a (small) protein at low (room) temperatures is uniquely determined by its amino acid sequence, which suggests that it might be possible to determine the 3D structure of a protein from its amino acid sequence by pure computations. As a step toward that goal, in this article we present a simple approach for parallelization of multicanonical Monte Carlo simulations of proteins with continuous potentials. Our method is based on the parallel calculation of the protein energy function. The algorithm is tested by simulated annealing and multicanonical simulations of two small peptides, and known results are reproduced accurately. An acceptable degree of parallelization can be achieved in the simulation of Protein L using up to 30 PCs. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1287–1296, 2001     

罗丹明6G荧光猝灭法测定微量钌

关于钌的三元络合物荧光分析法报道较少,S.Jaya曾报道基于Ru-SCN^--罗丹明6G三元络合物体系分析钌的分光光度法,罗丹明6G(简称R)染料分子中苯环之间有附加的氧桥,分子结构牢固,吸收光能不易失去,故产生荧光,钌(Ⅲ)与硫氰酸根形成的络阴离子与R的阳离子形成离子缔合物Ru(SCN)₆R₃,使罗丹明6G荧光猝灭,其猝灭值随钌的含量而增高,据此现象拟定了测定钌的方法,灵敏度较分光光度法提高20倍。