乙酸乙酯

For the same blending system, the penetration rates for acetic ether, absolute alcohol and gasoline, increase in sequence.

对同一体系，对乙酸乙酯渗透率最小，无水乙醇次之，汽油最大。

Ethyl acetate was a kind of important raw material and widely used in chemical industry.

乙酸乙酯是一种重要的化工原料，在化工生产的各个领域都有广泛的应用。

It was found that ethyl acetate was the optimal organic solvent.

结果表明，乙酸乙酯是最理想的有机溶剂。

This is accomplished by adding hexane to ethyl acetate.

这是藉由加入己烷至乙酸乙酯中来完成。

This paper reports on a rapid method for the determination of ethyl acetate based on UV spectroscopy.

提出了一种基于紫外-可见光谱法快速测定乙酸乙酯的方法。

In particular, methyl acrylate and ethyl acetate are widely used in industry.

丙烯酸甲酯和乙酸乙酯是工业上常用的有机物质，在生产和使用中产生的废气极易造成环境污染。

D limonene was distributed among the culture flasks (200 mg/L). The flasks were incubated at 28oC on a rotary shaker (r/min=120) for 5 days. On completion, the culture broth were successively extracted with EtOAc. The extract was quantitatively measured by gas chromatography mass spectrometry analysis, The results showed that biocatalytic reactions were comprised of oxidation, including hydroxylation and ketonization which occurred at different positions of the D limonene, as well as hydrogenation, hydrolyzation, esterification and cyclic cleavage. These bacteria strains possess the distinctive biocatalytic capacities towards the D limonene. A series of terpenoids, including sesqui , di and tri terpernoids were also observed,which was accounted for D limonene had influence on the metabolites of marine bacteria.

以2216E为培养基，添加200mg/L的柠檬烯，在28℃，以120 r/min摇瓶培养5 d，用乙酸乙酯提取培养液，经GC MS分析其转化产物，结果显示，这些细菌能在柠檬烯的不同位置进行羟基化、羰基化等，并伴随有还原、水解、酯化、开环等反应，但转化能力和转化程度不同；在产物中，还检测到系列结构不同的其它萜类：包括倍半萜、二萜以及三萜等，这些萜类化合物的产生跟柠檬烯的加入有关，说明柠檬烯能影响细菌代谢产物的产生。

The free fatty acids were extracted with petroleum ether and were separated on silicon gel column chromatography. The ethyl acetate-soluble lipid fraction and water-soluble lipid fraction were subjected to hydrochloric acid-catalyzed methanolysis, then were extracted with petroleum ether, respectively.

用石油醚提取低极性组分，经硅胶柱层析分离得到游离脂肪酸；用乙酸乙酯提取酯溶性神经酰胺及其衍生脂类，提取物和残余的水溶性脂类分别经盐酸甲醇解，水解产物再用石油醚提取。

The results showed that Kaidimycin was chemically neutral, macrocylic polylactones, stable and liable to dissolve into water and pyridine, slight to dissolve into methanol, ethanol and N-butanol, difficult to dissolve into ethyl acetate, acetone, benzene and chloroform. Chemical reaction of functional group of Kaidimycin showed that it had glycoside, amino acid and aldehyde, no reducing sugar, polypeptide and phenol.

凯地菌素属中等极性的、中性抗生素，极性纸层析结果与多烯类抗生素的纸层析结果相似：易溶于水、吡啶，微溶于甲醇、乙醇、正丁醇，不溶于乙酸乙酯、丙酮、苯、三氯化碳；对高温、光照和紫外处理有很好的稳定性；官能团反应试验结果发现，凯地菌素可能含有糖苷键、氨基酸伯氨基和醛基，不含有还原糖、多肽和酚基，高锰酸钾、浓硫酸反应与多烯大环内酯类抗生素的特性相似；并且依据纯品，采用生物法和分光光度法对摇床发酵液进行了效价的测定。

Then we completed the first total synthesis of-Plakoridine A using Eschenmoser couping reaction as akey step. During the synthesis we found the choice of protecting groups and the configuration of the chiralcenter of the substrate play an important role to the key Eschenmoser reaction,so we think our successwould be of guide for synthesizing other polysubstituted pyrrolidines or piperidines.

在论文的第一章中，我们先以易得的对羟基苯乙酸乙酯为原料经多步反应制得了所需的β氨基酸酯，然后利用立体选择性的Aldol缩合反应和内酰胺化反应制得了Plakoridine Alactam，随后，以Eshenmoser缩合反应为关键步骤完成了生物碱-Plakoridine A的首次不对称全合成。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。