催化作用

This thesis focused mainly on studying the role of planar chirality in asymmetric catalysis, synthesizing novel ferrocene ligands and applying them to palladium-catalyzed allylic substitution reactions.

本论文主要是研究二茂铁平面手性在不对称催化反应中的作用，设计合成新型二茂铁配体及其在钯催化烯丙基取代反应中的应用。

Based on the principles of autocatalysis and the theory of entropy, this paper tries to discuss and attest the autocatalytic mechanism in systems which cause general S curve.

运用熵理论和自催化原理对系统发展过程中普遍存在的 S型曲线的成因进行了论述和证明，指出系统出现 S型发展曲线是由系统的自催化机制和系统的限制因素共同作用引取。

Examples include trypsinogen and chymotrypsinogen, secrete d by the pancreas and converted by proteolysis in the small intestine into the active enzymes trypsin and chymotrypsin; and numerous coagulation factors.

这作用受不同的催化或受的活化型本身的催化。原细胞合成并贮存钝化型式的原。胰脏分泌的胰蛋白原及胰凝乳蛋白原在小肠内活化成胰蛋白及胰乳凝蛋白。

The reported organocatalyst for asymmetric Mannich reaction include proline derivatives, chiral phosphoric acids, chiralurea derivatives, cinchona alkaloids and so on, which can catalyze the asymmetric Mannich reaction with high catalytic activity and excellent enantiselectivity.

本文评述了各类有机催化剂在有机催化不对称Mannich 反应中的应用研究进展，以及不对称诱导反应的机理、催化剂分子结构及反应条件对其催化活性和不对称诱导作用的影响。

As well as activity was exhibited. Theaddition of cinchonidine led to a remarkable increase in the reaction rate, as confirmed bythe IR study that the modifier activates the carbonyl groups of the reactant through itsquinuclidine nitrogen. On the contrary,〓 exerted a strong inhibition effect on theenantioselective hydrogenation. Chapter 3 Finely dispersed polyvinylpyrrolidone-stabilized iridium andbimetallic clusters were prepared by the alcohol-water reduction method.

第三章 采用醇水还原的方法制备了聚乙烯基吡咯烷酮稳定的铱纳米簇及双金属纳米簇，对丙酮酸甲酯的催化氢化表明，在铱金属簇催化体系中，辛可尼定不仅诱导了一定的对映选择性，同时对反应活性有明显的促进作用，平均反应速率可提高2-6倍。

The results: the phase transferring range of TiO2 is between 600-750℃; with the doping of tourmaline, the UV-VIS adsorption spectrum of Nd/TiO2 was basically not affected, and showed a gradual Einstein shift with the increase of calcined temperature between 300-750℃; OH intensity of Nd/TiO2 could be enhanced both in irradiation and in no irradiation when tourmaline was added in it; the doping of 0.6% tourmaline led to the best photocatalytic activity of Nd/TiO2 and the best photocatalytic effect appeared when calcined at 600℃.

结果发现TiO2的相变转化区间在600~750℃范围内；电气石掺入对Nd/TiO2材料的光吸收范围基本没有影响，在300~750℃范围煅烧后，随温度升高UV-VIS图谱有逐渐红移现象；电气石的加入使得Nd/TiO2材料在光照及未光照条件下都起到增强OH强度的作用；在Nd/TiO2材料中掺入0.6%的电气石获得最好的光催化活性，600℃下煅烧光催化效果较优。

The photocatalytic behavior of such prepared nano-Cu2O was evaluated by the decomposition of acidic fuchsine solution under daylight. The influence of glucose addition and the initial concentration of acidic fuchsine solution as well as the catalyst reusability were examined.

用它做催化剂在日光作用下对酸性品红溶液进行了光催化降解实验，研究了葡萄糖添加浓度、酸性品红溶液的初始浓度和催化剂的重复使用对光催化性能的影响。

Therelationship of the amount of catalyst and the ee% of product was seen to be negative nonlin-ear. Catalyst 3 was used in the enantioselective addition of diethylzinc to aromatic aldehydesand gave good results. The configuration of products was determined by the configuration ofthe catalysts' chiral carbon linked with hydroxy group. Using β- amino alcohols bearing only one chiral center as catalysts for the enantiose-lective addition were studied. D-N, N-dialkyl-2-amino butanol gave poor catalytic effect be-cause of their structure. The configuration of the product is the same as the catalyst. Anotherkind of β- amino alcohols - phenylglycine derivatives and valine derivatives have chiralcenter on the carbon linked with amino group. Catalyzed by-phenylglycine derivatives 6,7, 9, 10, the reactions gave satisfied results. The optical yields exceeded 80%.

在探讨了含有两个手性中心的β-氨基醇之后，选择了只有一个手性中心的β-氨基醇，一是手性中心为连羟基的手性碳原子：D-N，N-二烷基-2-氨基丁醇；二是手性中心为连氨基的手性碳原子：D-苯基甘氨酸衍生物和L-缬氨酸衍生物。D-2-氨基丁醇的催化效果不太好，这与其结构的空间位阻较小有关系，反应产物与连羟基手性碳构型一致；由苯基甘氨酸和缬氨酸出发合成五种β-氨基醇6-10，研究了不同ee％的-6作用下的二乙基锌-苯甲醛加成反应，发现该催化剂具有不对称放大效应；-7，9，lO的催化效果也比较令人满意，光学产率80％以上，所得产物构型与催化剂构型一致。

NiRs are divided into two different types based on their prosthetic groups, namely heme-containing nitrite reductases (cd1-NiRs) and Copper-containing nitrite reductases.

Cu-NiRs呈三聚体结构，每个单体都含有两种类型的铜原子，它们在酶催化过程中起着传递电子的重要作用。在催化过程中，Cu-NiRs中部分残基的结构变化有利于催化反应的进行。

This photocatalyst was used to treat wastewater containing azo dye. It shows that natural rutile photocatalyst has certain photocatalytic action on azo dye.

用制备的天然金红石光催化材料处理含偶氮染料废水，结果表明其对偶氮染料的作用既有吸附，也有降解，表明天然金红石光催化材料有一定的光催化活性。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！