乙酯

Meanwhile the influence of the amount of catalyst alkali ethylate and absolute alcohol,the temperature and time of reaction on interesterification was studied.

利用正交试验研究了酯交换法制备卤虾油脂肪酸乙酯的工艺，分析了催化剂用量、反应温度、反应时间、无水乙醇用量等对醇解率的影响。

With this standard method, simultaneous quantification of DMC, MPC, DPC, phenol and anisole can be achieved accurately, which provide the standard methods for evaluation of different catalysts and control of the reaction process. The microwave-aided catalytic technique was applied in the transesterification of DMC and phenol.

分别以苯甲酸乙酯和丙酮为内标物，实现了对酯交换反应塔釜产品和塔顶馏分的同时定量，为评价催化剂活性的高低和工艺条件的优劣提供了标准化分析方法。

We constructed a CALB-displaying yeast whole-cell biocatalyst and applied it to esterification from caproic acid and ethanol.

重组酵母菌经冻干能有效地实现在非水相中全细胞催化己酸和乙醇酯化合成己酸乙酯。

Samples were saponified with 20 g/L sodium hydroxide. The sexual hormones were then extracted with dichloromethane-acetic acetate (40∶1, v/v) under acidic conditions (pH 3, adjusted with 1 mol/L HCl ). An XTerraTMRP18 column was employed and a mixture of water-methanol-acetonitrile (50∶32∶18, v/v) was used as mobile phase. The seven sexual hormones were detected at 230 nm. The average spiked recoveries for the seven sexual hormones ranged from 75.6% to 97.8% with relative standard deviations of 1.9% to 7.2%. The linear ranges of determination were from 5 to 50 mg/L with correlation coefficients of 0.9999, and the limits of detection were from 3.7 to 12 ng.

先在试样中加入20 g/L氢氧化钠溶液与油脂进行皂化反应，然后用二氯甲烷-乙酸乙酯(体积比为40∶1)混合液在酸性条件下(pH 3)萃取，选择XTerraTMRP18色谱柱，以水-甲醇-乙腈(体积比为50∶32∶18)混合液为流动相，在波长230 nm处检测。7种性激素分离良好并排除了样品中杂质峰的干扰，低、高浓度平均回收率范围为75.6%~97.8%；相对标准偏差为1.9%~7.2%；检出限为3.7~12 ng。

In view of the existence of the above shortcomings of traditional methods, using acetyl chloride instead of acetic acid as a raw material, do not use any catalyst, not heating, room temperature reaction synthesis of ethyl acetate.

鉴于传统方法存在以上缺点，采用乙酰氯代替乙酸作为原料，不使用任何催化剂，不加热，常温反应来合成乙酸乙酯。

Four substances including 2-methyl ethyl acetoacetate and barley straw extract distilled from bulrush as well as cetyl trimethyl ammonium bromide and isothiazo lintone were used for the comparison experiment in inhibiting the growth of Microcystis aeruginosa in various phases. Result showed that inputting chemicals in the lag phase has better effect than in the log phase, and adding in lag phase can effectively inhibit the algae growth. Although feeding allelopathic substance at log phase can lead to certain restraining effect, it cannot result in the effective inhibition of algae growth, which can be well achieved by feeding CTAB and isothiazo lintone below 10mgl/L during log phase.

研究用从芦苇中提取的2-甲基乙酰乙酸乙酯和大麦秸浸出液两种化感物质以及十六烷基溴化钱和异噻唑啉酮等四种药剂对不同生长期的铜绿微囊藻进行了对比抑制试验，结果显示在铜绿微囊藻生长的迟缓期投加试验药剂效果比在对数期投加效果都好，在迟缓期投加四种药剂，都有很好的抑藻效果；在铜绿微囊藻生长的对数期投加化感物质，虽然有一定的抑藻率，但效果较差，而在藻对数期投加10mg/L以下的CTAB和异噻唑啉酮能达到很好的水华抑制效果。

Could keep above 95% in the fixed beds. In order to achieve high stereo-selectivity with yeast, ethyl acetoacetate was used as the model substrate,and a novel approach was proposed to selectively inhibit R-enzymes in yeast before reaction.

以乙酰乙酸乙酯为模型底物，以丙烯酸、乙醚、二甲基亚砜、丙烯酰胺、正己烷等有机溶剂选择性地抑制酵母中R型酶，提高反应立体选择性。

7-Hydroxy-4-methylcoumarin was synthesized from ethyl acetoacetate and m-dihydroxybenzene by the Pechmann condensation using phenyl sulfonic acid as catalyst under solvent-free conditions.

摘 要：以苯磺酸作催化剂，乙酰乙酸乙酯和间苯二酚为原料，通过Pechmann缩合反应合成7-羟基-4-甲基香豆素。

Synthesis 3,5-dihydroxytoluene by ethyl acetoacetate and diketene as material(yield 6%),by 3-methyl-4-chlorophenol and KOH as material(yield 30-40%)respectively,It was solved for product separation and purify.

分别以乙酰乙酸乙酯与双乙烯酮为原料(收率6%)、3-甲基-4-氯苯酚与氢氧化钾为原料(收率30-40%)合成了3，5-二羟基甲苯，解决了产品分离纯化问题。3-甲基-4-氯苯酚路线进行了中试，中试收率为20%。

TEOS and PEG with different relative mol. wt. were used as raw materials to prepare single layer antireflective SiO2 films on borosilicate glass by sol-gel method. The relationships between preparing processes and optical properties of the films were investigated.

以正硅酸乙酯、不同相对分子量的聚乙二醇为主要原料，采用溶胶－凝胶法在硼硅酸盐玻璃板上制备单层SiO2减反射薄膜，研究了制备工艺对薄膜光学性能的影响。

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。