乙酯

The measurements were performed simultaneously by using a vibrating-wire instrument operating in the forced mode of oscillation.

采用振动弦黏度/密度计对碳酸二乙酯的黏度与密度进行了实验研究，测量的温度范围为263～363 K，压力范围为0.1～20 MPa。

Ethyl formate is a potential fumigant with properties of rapid insect control and being friendly to environment.

甲酸乙酯具有杀虫迅速及绿色环保等优点，是一种很有潜力的熏蒸剂。

A new method for the determination of methanol, ethyl acetate and fusel oils in the Chinese spirits by capillary gas chromatography was studied.

建立了一种用毛细管气相色谱法测定白酒中甲醇、乙酸乙酯和杂醇油的方法，并对色谱条件进行了优化。

A new method for the determination of methanol, Ethyl Acetate and fusel oils in sticky rice alcohol by capillary gas chromatography was studied.

建立了一种用毛细管气相色谱法测定糯米酒中甲醇、乙酸乙酯和杂醇油的方法，并对色谱条件进行了优化。

However, the gelation tune was decreased with the increase of water amount and increased with the increase of ethanol amount.

在类似"两步法"中，通过同时使用的氢氟酸和氨水，凝胶化时间更短，其最佳条件是无水乙醇和水与正硅酸四乙酯的体积比各自是4和0.6，同时加入氢氟酸和氨水的体积比为1：1时，获得的比表面积最大。

The results showed as follows: 1 Extraction of gelsemium total alkaloids. Total alkaloids were extracted with 95 per cent ethanol. The extract rate was 0.519 per cent and the extract purity were 88.02 per cent and 87.38 per cent; Total alkaloids were extracted with chloroform .The extract rate was 0.416 per cent and the extract purity were 89.02 per cent and 94.52 per cent. 2 Isolation of gelsemium total alkaloids with TLC. Total alkaloids contained five or more alkaloids. The optimal developing agent was chloroform :methanol :ethyl acetate(9:l:0.3),the optimal eluent was methylene chloride:methanol(92:8). 3 Isolation of total alkaloids with column chromatography. Alkaloid A and alkaloid B were obtained, alkaloid B was identified as koumine.

研究结果如下：1、钩吻总碱的提取：用95％的乙醇提取钩吻生物碱提取率为0.519％，其提取物纯度为88.02％、87.35％；用氯仿提取钩吻生物碱提取率为0.416％，其提取物纯度为89.02％、94.52％。2、钩吻总碱的薄层层析分离：总碱中含有5种或5种已上的生物碱；氯仿：甲醇：乙酸乙酯(9：1：0.3)是最佳薄层层析的展开剂；二氯甲烷：甲醇(92：8)是柱层析的最佳洗脱剂。3、钩吻总碱的柱层析分离：共得到两种钩吻生物碱单体成分碱A和碱B，碱B为钩吻素子，碱A可能是钩吻素甲。4、钩吻总碱的急性毒性试验：钩吻总碱小鼠腹腔注射的半数致死量LD_(50是：7.38mg／kg，95％的可信限范围为：6.67mg／kg～7.94mg／kg。

Therefore, the elimination of heptane would require replacement of ethyl acetate by a solvent in which 2 has a lower solubility.

因此，消除烷需更换乙酸乙酯溶剂中2具有低的溶解度。

As a consequence, in the course of our further optimization work we implemented the switch from ethyl acetate to isopropyl acetate, which enabled us to eliminate heptane in both crystallization steps.

影响所及，在我们的工作中，我们实行了进一步优化，转换为异丙乙酸乙酯醋酸这使我们能够在消除烷结晶步骤。

Our study is about extraction and purification of hesperidin from Citrus Poonensis one of the most important mandrin ...

现将主要研究结果报告如下： 1、用自制含NaOH溶液的硅胶板，采用乙酸乙酯：甲醇：水=10：3：2的展开剂，283nm紫外灯下可清楚的看到橙皮苷斑点呈黄绿色，斑点清晰圆润。

The effects of hapten structure on antibodies properties and hapten heterology on ELISA sensitivity were also investigated. The results show that haptens with simple spacer-arm can generate antibodies with desired properties, and hapten heterology can improve ELISA sensitivity significantly.

建立检测硫代磷酸二乙酯类农药的间接竞争酶联免疫分析方法，分析探讨了免疫半抗原结构对抗体特性的影响，并阐述了包被半抗原结构对ELISA灵敏度的影响规律。

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。