取代剂

Polywas directly halogenated to select halogenation agents such as Cl and Br and catalyst system.

通过将聚乙烯醇直接卤化取代，筛选出Cl、Br等卤化剂、催化剂，并优选出合适的体系，使其既保持PVA的高阻氧性，又能保证加工性时的热稳定

The studies of inhibitory activity of different hydantoin ARIs substituted by acetic acid residue can greatly benefit the structure-based drug design of ARIs.Keywords aldose reductase inhibitors, fidarestat, carboxylic acid methyl, synthesis,inhibitory activity

所分析的不同海因类抑制剂用乙酸链取代后的化合物的抑制性可以为以结构为基础的ARIs药物设计提供很好的实验基础。

Firstly, mixture of orthophosphate or sodium tripolophosphate was used as esterifying agent in preparation of cassava starch phosphaite by dry process.

首先，用混和正磷酸盐或三聚磷酸钠为酯化剂，干法制备高取代度木薯淀粉磷酸酯。

The methods of processing waste substrate when the amount is small are as follows: replace the sawdust to be the filling material of sculpture handicraft; make the soundproofing board, ceiling, vase and so on; be used as powder for the coating, paving material or filler for plastic preparation and so on; be reused as the reinforcing material and insulated gluing material or used as the fire retardant chemical.

摘 要：我国对废弃线路板基板的回收主要是采取填埋和焚烧的方法，处理少量废弃基板时有以下几种方法：取代木屑作为雕塑工艺品的填充物；制造隔音板、天花板、花瓶等；作为粉末用于涂料、铺路材料或是塑料制备的填料等；作为增强材料和绝缘胶粘材料重新利用或做阻火剂等。

Theoretical analysis and testing results demonstrated that Viton, a new substitute of the former plasticizer, could noticeably improve its performances, which has been proved as the important improvements of the mixture. Due to the favorable thermochemistry performance, dicyandiamide can act as a good combustion-rate regulator. The addition of antistatic agent can desirably increase the antistatic capability of the mixture, and the testing results showed that the performance of the improved mixture was excellent.

理论分析和测试结果均表明了以氟橡胶取代耐水点火药中原粘合剂将使药剂的各项性能有明显的改善，是耐水点火药改进的重要方面；双氰胺具有良好的热化学特性，作为耐水点火药改进中的燃烧速度调节剂具有很好的调速效果；抗静电剂的加入，进一步提高了药剂的抗静电能力，测试分析表明改进后药剂的性能更加优异。

The factors,including triphenyl phosphate content, hydrolization time,the volume of water and catalyzer concentration,affecting degree of substitution of cellulose triacetate in hydrolization are studied.

研究了增塑剂磷酸三苯酯含量、含水量、催化剂的比例以及水解时间对三醋酸纤维素水解产物取代度的影响。

A series of disubstituted monoamide s extractants were synthesized and their extracted species with uranyl nitrate were obtained by extraction method.

合成了系列双取代单酰胺萃取剂，利用萃取方法获得了与硝酸铀酰的萃合物。

Therefore esterification crosslinked reactionbetween polyearboxylic acid and wood can be quantitatively determined.According toexperiment results of stereoscopic configuration choices by crosslinking agents,crosslinkingreaction between model of reaction intermediate and wood,and the intermediate characteristic incrosslinking reaction,crosslinking reaction intermediate was proofed.We can infercrosslinking reactions between polycarboxylicacid and wood want through a mechanism of twosteps reaction process,the first cyclic anhydrides were formed as intermediates by dehydratingbetween hydroxyls in polycarboxylic acids,second esters were occurred by substitution reactionbetween wood hydroxyls and cyclic anhydrides.

从而可全面定量表征木材与多元羧酸类化合物的酯化交联反应；依据交联剂立体构型选择性、反应中间体模型物与木材的交联反应和交联反应中间体的波谱特征实验结果，证实了交联反应中间体，因此可以推测：多元羧酸类化合物与木材化学组分的交联反应是经历两步反应的机理，首先多元羧酸中相邻羧基的羟基之间脱水形成五元环酸酐中间体，然后木材的羟基与酸酐发生亲核取代反应形成酯。

Although these inhibitors including 19 compounds of benzylidene malononitrile family and 13 compounds of 3-substituted indolin-2-ones family, possess quite different structures,a common pharmacophore model with very good stratistical results was determined.

尽管亚苄基丙二腈化合物和3-取代吲哚啉-2-酮系列化合物具有完全不同的骨架结构，但得到的药效团却具有共同的特性，这表明当这两类抑制剂和受体发生相互作用时，采用了相似的结合模式。

Moreover, the substituents on the bicyclic chromophore can also produce strong van der Waals and hydrophobic interactions with the residues located at the exterior part of the binding pocket.

同时 ，抑制剂双环上的取代基团也能和活性口袋外部的部分残基形成一定的范德华和疏水相互作用。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。