查询词典 methyl group

This invention discloses an intermolecular charge transfer chromogen with triphenylamine group, with a formula indicated by (1), wherein: R1 is hydrogen atom or methyl group or methoxyl group, R2 is hydrogen atom or 2-(5,5-dimethyl-3-vinylcyclohexenyl-2-enylidene)propanedinitrile group.

本发明公开的含三苯胺基团的分子内电荷转移生色团，具有式1所示的结构式，其中R 1 为氢原子或甲基或甲氧基，R 2 为氢原子或2-(5，5-二甲基-3-乙烯环己烯基-2-烯亚基)丙二腈基。

The addition of the polyaluminophenylsiloxane during the curing of the resin raises the initial temperature of decomposition of the methyl group and lowers that of the phenyl group.

当引入聚铝苯基硅氧烷作为硅树脂固化催化剂，可提高其甲基的起始分解温度，同时降低苯基的起始分解温度。

The most preferable substituents are methyl groups for positions R1 and/or R2, due to the existence of a hyperconjugation effect between the p z orbital of the central carbon atom and one of the C—H bond orbitals in methyl group.

当R1， R2位置是甲基时，由于碳原子的p z 轨道与甲基的一个C—H键轨道间存在强的超共轭效应，从而可以较大程度地降低α-氢转移反应的势垒。

The integration of the methyl group of methylamine, based on the internal standard of the methylene group of ethanol, was measured and from which the amount of methylamine in the solution as well as the time that required can be derived.

以乙醇的亚甲基为内标，测量各种溶液情况下甲胺碳峰的积分值，可以判断该溶液甲胺所含的重量，以及达成某浓度所需通气时间。

We described that the nitro group is a stronger electron withdrawing and meta activating characters than the imide group, the amino and hydroxy are both electron donating groups and had ortho, para activating characters. The methyl group might have a steric hindrance effect in this reaction. Our results indicated that methyl group at the ortho position of the amino group on the benzene ring, the steric hindrance effect became stronger.

另一方面，由产率上的结果来看，可以得知硝基为强力的拉电子基团，会减少邻位和对位胺基的电子密度比间位多；而氢氧基与胺基是供电子基团，会增加邻位和对位胺基的电子密度比间位多；甲基取代对反应则只有立体障碍的影响，而且与反应的氨基成邻位存在下影响最大。

When the radical center is located at the bridge methyl group, ring expansion is the favored rearrangement pathway unless a radical-stabilizing substituent is placed in the cyclobutyl ring adjacent to the bridge methyl group.

当自由基中心位于双环的桥甲基时，扩环过程占主导地位，但是与桥甲基相邻的环丁基上存在能够稳定自由基的取代基时，重排以开环为主。

DFT were carried out to optimize the conformational isomers with minimum energies. Peak separations in the methyl and azomethine signals were also found to originate from the rotation hindrance of the N-N bond. After N'-acylideneacetohydrazides were converted to 1, 3, 4-oxadiazole compounds, the proton signal of the methyl group appeared as a single peak.

端甲基质子和次甲基质子信号裂分也来源于N-N键旋转受阻。N'-苄基酰腙通过缩合反应转变成1，3，4-二唑化合物，消除了甲基空间取向的差异，其信号变为单峰。

Tt can be seen from the table that, on the whole, the hydroxyl,methoxyl and dimethylamino groups activate the nucleuswhereas hydrogen, chlorine or the methyl group cativate the aldehyde group.

Tt能被从总体上桌子那看见，然而氢，氯或者甲基把cativate分组，羟基，methoxyl和dimethylamino组使核心

The ligand of HL3 differs from HL1 and HL2 in having an ethyl group not methyl group on the triazole ring and having a thienyl group on the substituted amino group, meanwhile there are two kinds of 3 molecules in the crystal structure.

在化合物3中配体与化合物1和化合物2的不同，同时其一个结构单元中还存在两个结构几乎相同的分子，这两个分子只在键长、键角上有轻微差别。

The results show that methyl group strengthens the electrostatic attractions, but reduces the H-bonds effect, while benzyl group can make both electrostatic and H-bond effects strong. The theoretical results are identical with the results of the collectors flotation tests. Collecting ability of the quaternary amine salts is better than that of dodecylamine and dodecyl bimethyl amine. The quaternary amine salt containing benzyl group performs best, and it is little affected by pH value. Substitution of N-containing polar group in amine collectors can impact the aluminosulicate minerals flotation.

研究结果表明：甲基的取代可增强阳离子的静电作用能力，同时，削弱它与矿物表面之间的氢键作用；苄基的取代不仅增强药剂的静电效应，而且增加氢键的结合能力；理论分析结果与浮选试验结果一致，季铵盐的浮选能力较伯胺与叔胺的强，连有苄基的季铵盐对铝硅酸盐矿物的捕收能力最强，且受pH值影响小。

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。