链烯

The side chain of thioacetic acid has been sythesized from the material of acetic acid via four steps, then synthesized the key intermediate of 2-hydroxypenem via displacement, P〓induced cyclization and hydrolyzed reaction from the material of azetidinone.

以羟乙酸为原料，经四步反应合成了侧链化合物硫基取代的羟乙酸，发生取代反应导入到经七步合成的单环氮杂环丁酮中，然后发生酰化，Wittig诱导环化，水解等五步反应合成关键中间体2-羟甲基青霉烯。

Firstly, the homopolymerization of acrylamide was carried out in aqueous phase by reversible addition-fragmentation chain transfer radical polymerization using a trithiocarbonate as a chain transfer agent.

整个过程分为两步，首先在水溶液中，通过RAFT控制得到亲水性单体丙烯酰胺的均聚物；然后以得到的均聚物作为水溶性的大分子链转移剂，在水相中条件下参与亲油性单体苯乙烯无皂乳液聚合。

The reason for inelastic deformation of unvulcanized rubber can be found in its chemical structure: rubber is composed of long polymer chains.

二烯烃类化合物在经过聚合后，主要生成的是线形的高分子长链。

The PMMA macromer was obtained by radical polymerization in the presence of 2-mercaptoethanol as a chain transfer agent, followed by termination with acryloyl chloride.

甲基丙烯酸甲酯进行自由基溶液聚合，巯基乙醇为链转移剂，然后用丙烯酰氯封端制备了聚甲基丙烯酸甲酯大分子单体。

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％。

In the course of our study the chemistry of arenes contaning allylic acetates moiety under the catalysis of palladium, we found an efficient synthesis of benzocycles via intramolecular Friedel-Crafts reaction of halogen free 6-acetoxy-4alkenyl arens.

我们在设计钯催化的碳—氢键活化时，发现了含有烯丙基醋酸酯侧链的芳烃的三氟醋酸促进的分子内的Friedel-Crafts反应，从而为有效合成苯并六元环结构提供了一个方便的方法。

The key steps were the stereospecific conversion of both allylie carbamates 10 and 13 into 11 by Li_2Cu_3(CH_2)_5 and the stereoselective hydroxylation of unsaturated side chain by OsO_4-NMO.

合成的关键步骤是用Li_2Cu_3(CH_3)_5立体专一地转化烯丙醇苯胺基甲酸酯10和13成为11和用OsO_4-NMO在化合物16的不饱和侧链上立体选择性羟基化。

Alkylation of C6D6 with 1-dodecene using Br-ALCl3 as a catalyst was firstly carried out. Molecular structures of products, dodecylbenzene isomers, were analyzed by GC-MS and NMR, and the deuterated atom in the dodecylbenzenes was verified to be connected with 1-carbon of the side chain.

首先进行了Br-AlCl3催化氘代苯与1-十二烯烃的反应，通过GC-MS及NMR分析产物十二烷基苯同分异构体的结构，验证了氘原子与产物侧链1-位碳相连的结论。

Non-selective fissions of the polyene chain, induced by abiotic factors like heat or light, result in a broad spectrum of oxidized breakdown products Beatriz et al.

非选择性裂变的多烯链，诱导非生物因素，如热或轻，造成了广泛的氧化击穿产品

With structure similar to that of vitamin K, Coenzyme Q10 also known as Ubiquinone 10 is a kind of fatsoluble quinone (C6H4O2), where "10" refers to the number of isoprenyl chemical subunits.

辅酶 Q10又名泛醌10，是一种脂溶性醌，其结构类似于维生素K，因其母核六位上的侧链——聚异戊烯基的聚合度为10而得名，是一种醌环类化合物。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。