查询词典 crotonate

An unusual intramolecular nucleophilic reaction of α carbon anion of crotonate was discovered and the imidazo[1,5 a ]pyridine derivatives were sythesized with a novel tandem reaction.

发现 5 咪唑甲醛(1)与γ溴代巴豆酸酯(2 )在弱碱条件下首先进行亲核取代反应生成 3，继而生成γ碳负离子并转移到α位，然后进行分子内亲核进攻成环、脱水生成 4的串联反应。

Condensation of cinnamaldehyde with methyl crotonate in the presence of alcohol-flee potassium methoxide gives,after hydrolysis,p-phenyl-benzoic acid in low yield.Its structure has been ascertained by direct comparison with an au- thentic sample.

桂皮醛与α-丁烯酸甲酯在催化剂去醇的甲氧基钾影响下进行反应，得到低产率的对-苯基-苯甲酸，共结构经用已知方法所得同样的酸直接加以比较而确定。

Densities and viscosities of the binary mixture of ethyl crotonate with ethanol at different compositions were determined at the temperature range from 293.15K to 343.15K and under atmospheric pressure by using a vibrating U-shaped tube densimeter and Ubbelohde suspended-level viscometer.

在常压下采用U形振动管密度计测定了巴豆酸乙酯与乙醇的混合液在293.15~343.15K下的密度。

The density and viscosity were measured by a vibrating densimeter(model DA-505U) and a Ubbelohde suspended-level viscometer at atmospheric pressure for ethyl crotonate + ethanol,crotonic acid + ethanol.

在常压下利用DA-505U型振动管密度仪、乌氏毛细管粘度计测定了巴豆酸乙酯-乙醇、巴豆酸-乙醇两个体系的密度和粘度。

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。