查询词典 chain reaction

The diblock copolymer of styrene and chloromethyl-4-vinyl-benzene was obtained by means of reverse addition fragmentation chain transfer reaction living free radical polymerization. The chloromethyl groups in PS-bPCVB were transformed into azidomethyl groups, and then into 1,2,3-triazol groups via click chemistry. The diblobk copolymer containing 1,2,3-triazol groups was thus obtained. The results from NMR spectra suggested a complete transformation from chloromethyl groups to triazol groups.

通过RAFT活自由基聚合方法制备聚（苯乙烯-b-对氯亚甲基苯乙烯）二嵌段共聚物，其中的氯亚甲基侧基经叠氮化反应后与丙炔醇进行点击反应，最终获得了含有1，2，3-三氮唑官能团的聚苯乙烯二嵌段共聚物，核磁共振谱表征结果证明，PS-b-PCVB中的氯亚甲基完全转变成了1，2，3-三氮唑基团。

The diblock copolymer of styrene and chloromethyl-4-vinyl-benzene was obtained by means of reverse addition fragmentation chain transfer reaction living free radical polymerization. The chloromethyl groups in PS-b-PCVB were transformed into azidomethyl groups, and then into 1,2,3-triazol groups via click chemistry. The diblobk copolymer containing 1,2,3-triazol groups was thus obtained. The results from NMR spectra suggested a complete transformation from chloromethyl groups to triazol groups.

通过可逆加成－断裂链转移聚合活性自由基聚合方法制备了聚（苯乙烯－b-对氯亚甲基苯乙烯）二嵌段共聚物，其中的氯亚甲基侧基经叠氮化反应后与丙炔醇进行点击反应，最终得到了含有1，2，3-三氮唑官能团的聚苯乙烯二嵌段共聚物，核磁共振谱表征结果证明，PS-b-PCVB中的氯亚甲基完全转变成了1，2，3-三氮唑基团。

In this article, the factors that affect molecular weight and solubility of polyacrylamide are studied and suitable initiator system is selected. The optimum parameters of copolymerizing process are obtained as follows: the molar proportion of acrylamide and sodium acrylate is 7:3, the monomer concentration is 30%, pH value of solution is 12, the oxidizer (K2S2O8) concentration is 0.1%, the reducing agent (NH2CONH2) concentration is 1%, the chain-transfer agent concentration is 0.4%. The initial reaction temperature is 35℃.

讨论了影响聚丙烯酰胺分子量和溶解性能的因素，选取了合适的氧化-还原引发体系，确定了制备超高分子量速溶型部分水解聚丙烯酰胺的优化聚合工艺参数：起始共聚合反应温度为35℃，保持在密闭条件下的共聚合反应2.5h后，再将聚合反应温度升高到55℃，继续反应2h，反应结束；反应溶液单体总浓度：30％，共聚合反应溶液pH值：12，氧化剂K_2S_2O_8：0.1％，还原剂NH_2CONH_2：1％，共聚合反应中两种单体的投料比：丙烯酰胺：丙烯酸钠=7：3，异丙醇链转移剂：0.4％。

Phenolic agent in alkaline lignin separated fromthe the black liquid can result in a chain etherized reaction on cycloalkanes by alkaline distilling so as to make lignin change its property.

本文对碱木素胺化改性过程中涉及的黑液提取、木素分离方法、碱木素胺化以及其作为沥青乳化剂的应用现状与发展前景等做了较为详细的综述

Phenolic agent in alkaline lignin separated fromthe the black liquid can result in a chain etherized reaction on cycloalkanes by alkaline distilling so as to make lignin change its property.

从蒸煮黑液中分离的碱木素苯环上的酚羟基可与环氧烷基胺发生醚化接枝反应，从而使木素胺化改性。

Not only increased the rapid-reaction capability, but also reasonable inosculated with supply chain.

不仅增加了快速反应能力，还与供应链合理的融为一体。

Reaction of L-tyrosine with benzyl bromide in the presence of copper sulfate led to the protection of phenol group on the side chain of L-tyrosine to give H-Tyr-OH in 45% yield via a copper complex intermediate.

酪氨酸与溴化苄在硫酸铜存在下反应，选择性地在其侧链酚羟基上引入苄基保护基，通过反应条件的优化，反应产率达到45%。

The fitted dynamics model parameters are as following:In order to apply the reaction distillation technology in more fields, the methylbenzene side-chain photo-chlorination has been done in the experiment apparatus. The results have proven this technology is feasible and crude benzyl chloride with a purity of 96~98% can be obtained.

估计得到的动力学模型为：为扩大背包式反应精馏耦合工艺的应用范围，在所建立的实验装置上，进行了甲苯侧链光氯化反应的研究，结果表明工艺可行，可以得到含量96～98％的氯化苄粗品。

To improve the nonlinear optical property and stability of azo-dye chromophore, the nonlinear optical polyimide attached with azo chromophore side-chain is synthesized by diazo coupling reaction of 4-nitrohenzediazonium tetrafloroborate.

为了提高材料的非线性光学性能和偶氮染料发色团的稳定性能，通过对－稍基苯基重氮氟硼酸盐的重氮偶合反应，合成了侧链含偶氮非线性光学活性基团的聚酰亚胺材料，幷用红外光谱对其进行了结构表徵。

Little literature on the aspect of surfactants containing boron with long-carbon chain alkyls had been found.Using diethanolamine, boric acid, hexadecanol as starting materials, after a series of reaction such as vapour phase process bromizating, esterifying, alkylating, a new type of surfactants with boron RNB had been obtained. The structures of the compounds had been identified by elemental analysis, IR and HNMR.

本论文采用二乙醇胺、硼酸、十六醇等为主要原料，经气相法溴化、酯化、烷基化等一系列反应合成了一种新型含硼表面活性剂RNB，并通过元素分析、红外、核磁对其结构进行了确认。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。