丁烯酸

An ester or a salt of perchloric acid .relating to or producing butyric acid .

顺丁烯二酸氧化形成的酸（如在脂肪和碳水化合物的新陈代谢中）。

Diethyl fumarate was synthesized with fumaric and alcohol as raw materials and sodium acid sulfate as catalyst.

富马酸二乙酯(又名反丁烯二酸二乙酯，Diethylfumarate，简称DEF)是一种用途广泛的有机合成中间体[1，2]。

An acid formed by oxidation of maleic acid (as in metabolism of fats and carbohydrates).

顺丁烯二酸氧化形成的酸（如在脂肪和碳水化合物的新陈代谢中）。

The worn surface was analyzed with X-ray photoelectron spectroscopy, scanning electron microscopy and electron probe microanalysis.

通过与廿二酸和硫化异丁烯的对比研究发现，在廿二酸中引入硫后，氧与硫产生了明显的协同减摩抗磨及承载作用。

During the manufacturing of the critical intermediate cephalosporin nucleus --7-amino-3-chloro-cephalosporanic acid diphenylmethyl ester hydrochloride salt, first the feasibility of the one-pot synthetic route of open loop, closed loop and ozonization when chlorine is passed over is qualified by experiments. Then the critical factors that will influence this reaction are studied as follows: the mol ratio of triphenyl phosphite and Diphenylmethyl 3-hydroxy-7-phenylacetaminoceph-3-em-4-carboxylate-l-oxide is four to one; the quantity of the stablizer should be at least more than two to one. The temperature of the system must be 25℃ when chlorine is passed over so that the hydrochloride can be precipitated to obtain cephalosporin nucleus of cefaclor--7-amino-3-chloro-cephalosporanic acid diphenylmethyl ester hydrochloride salt.

在制备关键中间体头孢母核7-氨基-3-氯头孢烷酸二苯甲酯盐酸盐时，先通过实验验证把开环、闭环、臭氧化三步在通入氯气时并为一锅煮的合成路线的可行性之外，又研究了影响该反应的几个重要因素：亚磷酸三苯酯与3-羟基-7-头孢烷-5-亚砜-2-甲酸二苯甲酯的摩尔比为4：1；稳定剂2-甲基-2-丁烯的用量至少大于2：1，通入氯化氢气体时体系温度在25℃时盐酸盐则能够顺利析出，获得头孢克洛的头孢母核—7-氨基-3-氯头孢烷酸二苯甲酯盐酸盐。

Experimental wastewater was composed of glucose and potassium sorbate wastewater.

废水的组成包括丁烯醛、山梨酸、山梨酸钾以及生产过程的载液、丙酮、醋酸、乙醇、甲醇等。

The results showed in the seven food preservative s,that calcium propionate had no effect on the growth of Peronophythoral litchii,while cinnamyl glyceroyl fumarate was the best.

结果表明：在所用的7种食品防腐剂中，丙酸钙对荔枝霜疫霉菌的生长无抑制作用，反丁烯二酸桂醇甘醇酯的抑菌效果最好

ABSTRACT In this paper, by employing dicarboxylic acids with special conformation, i.

利用几个结构上有特点的二元羧酸，即2，6-吡啶二甲酸、三个异构体苯二甲酸，顺丁烯二酸和4，4'-联苯甲酸作为首要桥基配体，并结合使用含氮中性配。。。

In this experiment we use the alcohol to replace the Fumaric acid and using the NaOH and HCl to control the pH number.

而本实验就是以过锰酸钾加入酒精以代替过去使用的反丁烯二酸并以HCl及NaOH来调控其酸碱值并比较其反应后的各种性质。

The above resins are irregular transparent solid which are the products of esterification by pentaerythrite and the adducts of rosin and maleic anhydride.

马林酸树脂又名失水苹果酸树脂，由松香与顺丁烯二酸酐加成反应后并以多元醇酯化而制得的不规则透明粒片状固体。

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。