乙酸乙酯

Various fractions of tannins with different polarities and relatively narrow molecular weight distribution were obtained by extractions using ether and ethyl acetate sequently.

通过乙醚和乙酸乙酯萃取可得到极性不同的组分。分析表明，各级分的分子量分布范围不同，且相对较窄。

The catalysts for the combustion of ethyl acetat ewer eprepared using Fe,Co,Cu,Cr,and Mn metal oxides as active components supported on Al2O3-Ce0.5Zr0.5O2 mixed oxides and characterized by X-ray diffraction,temperature programmed reduction,oxygen storage capacity measurement,BET surface area,XPS measurement,and activity test.

制备了Fe，Co，Cu，Cr和Mn金属氧化物催化剂，所用载体为Al2O3-Ce0.5Zr0.5O2复合氧化物。利用X射线衍射，程序升温还原，储氧量测试，BET比表面测试和光电子能谱表征了催化剂。并利用活性测试表征了各种催化剂对乙酸乙酯催化燃烧能力。

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。

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 antibiotic substance was isolated and purified primary using the methods of solvent extraction and Thin Layer Chromatography. The results showed that the antibiotic substance contained four components, and the component Ⅰ and Ⅱ had bioactivity against Cmm.

通过乙酸乙酯抽提、旋转蒸发制备的活性物质粗提液经薄层层析分析后，共分离出四个组份，其中仅组份Ⅰ与组份Ⅱ对番茄溃疡病菌表现抑制作用；紫外及可见光区的吸收峰分别为：253 nm、424 nm和443 nm。

The control group were fed basal diet, group 1 to 3 were fed basal diet supplemented with 90,100,110 mg/kg of Lespedeza Bicolor crude extract, group 4 to 6 were fed basal diet supplemented with 60,70,80 mg/kg of ethyl acetate extract, group 7 to 9 were fed basal diet supplemented with 60,70,80 mg/kg of n-butanol extract.

试验期42 d。对照组饲喂基础日粮，1～3 组饲喂基础日粮加二色胡枝子粗提物90、100、110 mg/kg；4～6 组饲喂基础日粮加二色胡枝子乙酸乙酯萃取物60、70、80 mg/kg；7～9 组饲喂基础日粮加二色胡枝子正丁醇萃取物60、70、80 mg/kg。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。