查询词典 methyl group

A series of polymers containing 1,8-naphthalimide moieties in the side chains have been prepared via RAFT technique. Firstly, five styrene and two methyl acrylate based 1,8-naphthalimide monomers were synthesized and characterized. Then, carbazyl group terminated polystyrene was used as macromolecular RAFT agent.

我们合成了5种苯乙烯类和2种甲基丙烯酸酯类萘酰亚胺单体，以一种含末端带咔唑结构的聚苯乙烯为大分子RAFT试剂，考察了所得单体的RAFT聚合，发现苯乙烯类1，8-萘酰亚胺单体可以聚合，但是聚合度不高，甲基丙烯酸酯类1，8-萘酰亚胺单体RAFT聚合不可控。

Organic our country high polymer flocculant already has commercialized at present having several breeds such as PAM , polypropylene acidamides and carboxyl methyl cellulose only , studies innocuous high-effect organic synthesis high polymer flocculant (the ammonium equality gathers the sum copolymer kind if alkyl alkene propyl group halogenates waiting), optimizes it's the cost reduction composing handicraft.

目前我国有机高分子絮凝剂已商品化的仅有PAM、聚丙烯酰胺和羧甲基纤维素等几个品种，研究高效无毒的有机合成高分子絮凝剂(如烷基烯丙基卤化铵的均聚和共聚物类等)，优化其合成工艺降低成本。

According to the results of the examination, the stronger the electron-withdrawing protective group of imines, the better the cis-selectivity of the reaction, 68% yield, trans:cis is 99:1 diastereoselectivity could be leaded by Ts-imines (4-methyl-N-methylene-benzenesulfonaides) with a substituent [2,4-(CH3O)2C6H3], Substrate scope investigation revealed that a wide variety of ketenes and imines could react smoothly to afford corresponding,β-lactams.

实验结果表明，亚胺的保护基团吸电子能力越强，越有利于顺式产物的生成。对甲苯磺酰基保护的取代基为2，4-二甲氧苯基的亚胺参与的该反应可得到68%的产率，反式：顺式=99：1的非对映选择性。底物拓展过程中发现Staudinger反应适用于多种不同的亚胺与烯酮。

Codeine has the same structure as morphine, but the phenol group is masked as a methyl ether.

可待因也有和吗啡相同的结构，但是酚基被甲基醚屏蔽了，结果。

Naturally occurring terpenes constitute the largest group of natural products with complicated and variable structures and a great number of important biological activities.2-Methyl-D-erythreitol 4-phosphate pathway is a newly found and established biosynthetic route for terpenoids and all the enzymes involved in this pathway can be used as targets for the screening of new antibiotics.

萜类化合物构成了最大的一个天然产物家族，结构复杂多变，且有许多重要的生理活性。2-甲基-D-赤藓糖醇4-磷酸途径是近年来发现并建立的一条萜类化合物的生物合成途径，其中所涉及到的酶均可作为靶标来进行新抗菌素的筛选。

Then dendrimer-like polyamidoamine on the silica gel surface was prepared using Micheal addition of the amino and methyl acrylate,and ester-exchange of ethylene diamine and the ester group.

用硅烷偶联剂对硅胶表面进行氨基功能化，利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺-胺树状大分子。

The effect of molecular weight, ethylene group and mixing of polyketone on the photodegradability were investigated. The mechanism of the photodegradation of ESTCO, STCO, STCO-PS and ESTCO-PS were reviewed. In addition, the block polymerization of methyl methacrylate initiated by STCO under UV irradiations was also studied.

研究了乙基取代基、分子量及共混物对聚酮光降解性能的影响，探索了STCO、ESTCO及其分别与聚苯乙烯共混物STCO-PS、ESTCO-PS的光降解行为和光降解机理，初步探讨了聚酮ESTCO光降解所产生的大分子自由基引发的甲基丙烯酸甲酯的聚合。

Then dendrimer-like polyamidoamine s based on the silica gel surface were prepared using Micheal addition of the amino and methyl acrylate,and ester-exchange of ethylene diamine and the ester group.

用硅烷偶联剂对硅胶表面进行氨基功能化，利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺-胺树状大分子；利用红外光谱对PAMAM-SG的结构进行了表征，研究了溶液pH值、ρ(Ni2+)和温度对PAMAM-SG吸附Ni2+能力的影响。

Amino functional silica gel was synthesized by reacting silane coupling agent with silica gel. Then dendrimer-like polyamidoamine on the silica gel surface was prepared using Micheal addition of the amino and methyl acrylate, and ester-exchange of ethylene diamine and the ester group.

用硅烷偶联剂对硅胶表面进行氨基功能化，利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺－胺树状大分子。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。