查询词典 Chain Reaction

First, the precursor polymer with azobenzene groups on main-chain was obtained by condensation polymerization between 4,4'-dihydroxyazobenzene and N,N-(2-bromoethyl)aniline through Williamson reaction. Then the azo polymer containing azobenzene groups both on main-chain and side-chain was prepared through an azo-coupling reaction between the precursor polymer and the diazonium salt of 4-nitroaniline.

设计并合成了一种新型的主侧链均含偶氮生色团的聚合物，首先通过4，4'-二羟基偶氮苯与N，N-二溴乙基苯胺之间的Williamson反应缩聚得到主链含偶氮苯基团的先驱聚合物，再通过重氮偶合反应得到目标产物，并利用核磁共振、红外光谱、紫外可见光谱、热分析等手段确认了所制备聚合物的结构。

The method is characterized in that: mixture of macromolecular dihydric alcohol and a dihydroxybutyl-terminated polydimethylsiloxane is dehydrated, added with diisocyanate for reaction, then added with a bis propionic acid, a dihydric alcohol chain extender and a catalyst - dibutyl tin laurate, and is diluted by acrylic ester; temperature reduction and emulsion are performed on the mixture after reaction; chain extension reaction is performed in water by a multi-amine chain extender, and siloxane modified polyurethane dispersoid which contains acrylic ester monomer is prepared; and an initiator - potassium persulphate is added into the siloxane modified polyurethane dispersoid for emulsion polymerization.

特征是先将大分子二元醇与二端羟丁基聚二甲基硅氧烷的混合液脱水后加入二异氰酸酯，反应后加入二羟甲基丙酸、二元醇扩链剂和催化剂二月桂酸二丁基锡，并用丙烯酸酯进行稀释，反应后降温乳化，用多元胺扩链剂在水中进行扩链反应，得到含有丙烯酸酯单体的硅氧烷改性聚氨酯分散体，然后再通过加入引发剂过硫酸钾进行乳液聚合。

The chain-condensation reaction and its reversible reaction are the key controlling elementary reactions of the copolymerization mechanism for the studied system,while the chain initiation elementary reactions are not the key controlling elementary reactions of the copolymerization mechanism for the studied system.

其中，链引发及其逆反应对D4/APAEDMS的本体共聚反应没有直接调控作用，而链缩合及其逆反应是本体系反应机理不同于纯活性阴离子聚合或逐步聚合反应机理的关键原因。

The operating range suitable for three-phase reaction was obtained and a mathematical model established. The results show that MSB formed by fine magnetizable powder and fliudizing flow can be operated stably in a wide range. MSB has three kinds of regimes: particulate, chain, and magnetically condensed. In these regimes, the chain regime is the best for three-phase reaction. When Ni-RE-P catalyst particles mixed with some iron powder, magnetically stabilization is easily achieved; therefore, it is possible that NiRE-P catalyst can be controlled in the bed for reaction more easilly if adding certain percentage of iron powder.

研究结果表明：细粉铁磁性颗粒形成的磁稳定床可在较宽流速范围内稳定操作，该磁稳定床有三种操作状态：散粒状态，链式状态和磁聚状态，其中有利于进行气液固三相反应的操作状态是链式状态；当磁稳定床在最小流化速度和带出速度之间操作时，床层处于链式状态；最小流化速度和带出速度可用（1-24）、（1-25）、（1-27）、（1-33）式计算；弱软磁性Ni-RE-P非晶催化剂中混入定量铁粉颗粒后便可形成磁稳定床，因此利用混入铁粉颗粒在外加磁场作用下控制弱磁性非晶催化剂颗粒进行反应的方法是可能的。

Preparation of the lateral chain-4-benzyloxy-3-hydroxy butyronitrile is introduced as the substrate, the REFORMATSKY reaction is performed, then obtains the dicarbonyl ester, in the structure of which containing a chiral hydroxyl group, then performs the chiral reduction, take off the benzyl group after the protection reaction with acetonylidene,then obtains the lateral chain by oxidation.

手性侧链醛的合成：采用-4-苄氧基-3-羟基丁腈作为底物，通过REFORMATSKY反应缩合得到含有手性羟基的二羰物酯，再手性还原，丙酮叉保护后氢解脱苄，最后氧化得到侧链醛。

Syntheses of PPVs derivatives containing oxadizole by Heck reaction Chromophore of oxadizole was introduced into the chain of PPVs derivatives with alkoxyl as side-chain by Heck reaction.

二。通过Heck反应在PPV主链结构中引入噁二唑基团通过Heck反应将噁二唑引入了不同烷氧取代的PPV高分子主链，所得高分子在THF、DMF等常见溶剂中有较大的溶解度。

In this thesis, a series of complexes based on aromatic multicarboxylic acids have been successfully synthesized in solutions or under hydrothermal conditions. Their structure and properties are investigated.(1) Eight complex compounds have been synthesized and characterized by X-ray single crystal diffractive technology: The eight complexes are listed as following: [Cu242] complex 1 [Cd22(H2O)4]·4H2O complex 2 [Co(H2btc)(H2O)3] complex 3 [Co2(H2O)2]·H2O complex 4 [Ni22(H2O)4] complex 5 [Cu22(H2O)4] complex 6 [Co(H2biim)2(H2O)2](H2btc) complex 7 [Zn(H2biim)2(H2O)2](H2btc) complex 8 The structure of complex 1 is dinuclear complex resulted from weak interactions（0-D chain）; complex 2 is 1-D chain stucture result from interactions of water molecules; complex 3、4、5、6 are coordination polymers using hydrothermal synthses, where the first kind ligand is H4btc, the second kind ligand is phen and Co2+、Ni2+、Cu2+ as center ions, respectively. While the coordination enviroment of Co2+ is the same in complex 3, the coordination geometries around the Co atoms in complex 4 are obviously different because of the different reaction conditions. In complex 4, the 1-D chains are connected into 2-D layer through carboxy groups of ligand H4btc. The structures of complex 5、6 are 1-D chain stucture result from interactions of carboxy groups in ligand H4btc. Complex 7、8 are homeomorphy compounds. Either of them are linked to the 3-D chains through intermolecular hydrogen bonds. Each H4btc lose two protons and H2btc2- acts as negative electron balance.

合成了8个结构新颖的配合物，并用X-射线单晶结构分析方法确定了晶体结构，分别为： [Cu242] 配合物1 [Cd22(H2O)4]·4H2O 配合物2 [Co(H2btc)(H2O)3] 配合物3 [Co2(H2O)2]·H2O 配合物4 [Ni22(H2O)4] 配合物5 [Cu22(H2O)4] 配合物6 [Co(H2biim)2(H2O)2](H2btc)配合物7 [Zn(H2biim)2(H2O)2](H2btc)配合物8 配合物1是一个依靠弱作用连接的双核铜结构；配合物2借助水分子形成一维链状结构；配合物3、4、5、6是以H4btc为第一配体、phen为第二配体，通过水热法合成的配合物，其中，Co2+、Ni2+、Cu2+为中心离子；配合物3中的二价钴离子具有相同的配位环境，不同反应条件下得到的配合物4中的二价钴离子存在不同的配位环境，在配合物4中，一维链通过H4btc上的羧基形成一个二维层结构；配合物5、6是借助H4btc上的羧基形成的一维链状结构；配合物7、8属于异质同晶结构，它们的分子通过分子间氢键形成三维网状结构，H4btc上的羧基失去2个质子，作为一个二价负离子起到电荷平衡作用。

For the high affinity sites, binding constant decreases with the decrease of the alkyl chain lengh in the surfactants, but for the low affinity sites, binding constant increases and are not distinct when the alkyl chain is dedocyl. The binding sites are related to the alkyl chain lengh, not for the number of hydrophile groups and temperature.Isothermal titration calorimetry has been used to observe the enzyme-catalyzed hydrolysis reaction of urea.

对于高结合位点，结合常数随疏水碳链长度的减小而减小；对于低结合位点，结合常数随疏水碳链长度的减小而增大，相应的当碳链减小至C12时，低结合位点不明显，结合位点数可能只与碳链长度有关，随亲水头基和温度变化不明显。

Methods HLA-A,B typing of 50 patients with EHF were investigated by polymerase chain reaction-sequence specific primer.

方法采用聚合酶链反应-序列特异性引物技术，检测流行性出血热患者的HLA-A、-B等位基因。

Methods The polymorphisms of HLA-DRB1 and-DQB1 alleles were typed by sequence specific primer based on polymerase chain reaction in 50 patients with EHF and 50 normal control subjects.

应用序列特异性引物聚合酶链反应技术检测流行性出血热患者和正常对照组各50例的HLA-DRB1、DQB1等位基因。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。