催化作用

It is the first time that acid-base bifunctional catalytic mechanism to transesterification is proposed.

具有协同作用的酸碱双功能的催化机理属于首次提出。

Anilido-imino nickel complex 1 {(C6H3Me2-2,6)N=CH-5-NO2-C6H3N (C6H3Me2-2,6)}NiBr was first synthesized, and its catalytic behavior toward polymerizations of norbornene and ethylene in the presense of methylaluminoxane were investigated in detail. The complex activated with methylaluminoxane exhibited high activities for norbornene polymerization.

首次合成了苯胺基亚胺镍配合物1{(C6H3Me2-2，6)N=CH-5-NO2-C6H3N(C6H3Me2-2，6)}NiBr，研究了其在助催化剂甲基铝氧烷的作用下对降冰片烯、乙烯的均聚以及对降冰片烯和乙烯的共聚的催化性能。

In addition, the catalytic reaction of hydroxyl radicals also have a wide range of bacteria killing effect.

此外，催化反应产生的氢氧自由基还对多种病菌具有杀灭作用。

In the function of sodium methoxide, several factors effecting on alcoholysis of urea by zinc oxide catalyst were obtained.

探讨了在甲醇钠作用下，氧化锌催化尿素醇解的影响因素。

Carboxylic acid was peroxidized in organic solvents catalyzed by lipase and glycidol was synthesized from allyl alcohol catalyzed by acid peroxide.

利用脂肪酶在有机介质中催化制备过氧酸，丙烯醇在过氧酸的作用下发生环氧化反应生成环氧丙醇。

There were few successful examples of regioselectivity in reactions of unsymmetrically allylic derivatives, and enantioselectivities obtained with prochiral nucleophiles.

因而我们选用反应机理相对比较清楚的钯催化烯丙基取代反应来研究平面手性的作用。

Then Doripenem came into the market in the July ,2005. We studied the synthesis of Doripemen.Firstly, we synthesized the chemical 2 from the starting material------o-hydroxylphenylacylamine through Reformastky reaction, alkylation, Diekmann reaction, enolization, esterification and etc. Secondly, we synthesized the chemical 3 from L — hydroxylproline through the protection of carboxyl, amidogen and hydroxyl group, reduction by NaBr, SN_2 substitution and Mitsumobu reaction.

我们以水杨酰胺为起始原料，经Reformatsky反应、烷基化、Diekmann环合、烯醇化、酯化等反应合成双环母核2；再从L-羟基脯氨酸出发，经酯化保护羧基、保护氨基、保护羟基、硼氢化还原酯得醇、Sn2取代和Mitsumobu反应等合成巯基侧链3；最后由化合物3经脱保护、水解得硫醇，和化合物2在二异丙基乙基胺的作用下缩合，最后Pd／C催化脱保护，历经16步反应最终得到产物多尼培南。

Asymmetric autocatalysis combined with chirality amplification has been made the new concept in chirality origin .

不对称自催化反应结合手性放大作用，使人们对手性起源有了新的认识。

Meanwhile, different trades and industries are benefited from the fine operation which has polymerized the limited commercial resource.

业务往来和行业交融，起到了催化和联结作用，体现了精益经营对有限商业资源的聚合作用。

Nationwide sampling program is designed according to the resources distribution and coal-forming periods as well as coal rank and yield of coal in China, 305 coal samples were collected and determined by catalytic spectrophotometry combined with pyrohydrolysis.The geochemical mechanism of the concentration or depletion of iodine was discussed during the process of coalification,which including peat diagenesis and coal metamorphism.The contents of iodine in Chinese coals fall in the range of 0.04-39.51 mg/kg.

根据中国煤炭资源分布和成煤时代，兼顾煤的变质程度和煤炭产量分布，在全国范围内采集了305个煤样，采用高温热水解—催化分光光度法分析了煤中碘的含量，探讨了煤化作用(包括泥炭成岩作用和煤变质作用)过程中煤中碘富集或亏损的地球化学机制。

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！