查询词典 acetacetic ester

Phenetole ;α-oxo-p-ethoxyphenylacetic acid ethyl ester ; ethyl-2-（p-ethoxyphenyl） propenoate ; synthesis

苯乙醚；α-羰基-对乙氧基-苯乙酸乙酯； 2-对乙氧基苯基丙烯酸乙酯；合成

The immobilized enzyme from Bacillis megaterium gave a better catalytic properties and the higher conversion was obtained using phenylglycine methyl ester as acyl donor.

来源于巨大芽孢杆菌的固定化酶催化头孢克罗合成的能力较好，以苯甘氨酸甲酯为底物较酰氨的效果好。

In a system consisting of 20% PEG 400 and 12% magnesium sulfate, the partition coefficient of PGA was less than 0.01, PGA almost completely partitioned into the magnesium sulfate-rich bottom phase. Meanwhile, the partition coefficient of cephalexin was 6.7, the partition coefficients of phenylglycine methyl ester and 7-ADCA were 1.5 and 1.2, respectively.

通过考察头孢氨苄、苯甘氨酸甲酯和7-氨基脱乙酰氧基头孢烷酸(7-ADCA)在ATPS中的分配行为建立了一个含20%PEG 400和12%硫酸镁的ATPS，在此体系中头孢氨苄的分配系数为6.7，苯甘氨酸甲酯的分配系数为1.5，7-ADCA的分配系数为1.2，且青霉素酰化酶的分配系数小於0.01。

Furthermore,enzymatic production of cephalexin using free penicillin G acylase in aqueous system wasstudied. The parameters, including pH, temperature, concentration of 7-ADCA and molar ratiosof 7-ADCA to phenylglycine methyl ester, that affect the yield of cephalexin, wereevaluated. In section Ⅱ, the integration technique of bioseparation and biosynthesis was investigatedfirst time in the enzymatic production of cephalexin.

第Ⅰ部分主要建立了对酶法合成头孢氨苄过程行之有效的HPLC检测方法，实现了头孢氨苄合成过程中所涉及的四种物质，即头孢氨苄、苯甘氨酸甲酯、苯甘氨酸及7-ADCA快速有效的检测；同时对水相体系中头孢氨苄合成过程的影响因素进行了研究，明确了水相体系中温度、pH值，底物浓度以及底物配比对酶法合成头孢氨苄得率的影响。

ABSTRACT Immobilized penicillin acylase (from E.coli) was used to catalyze 7 phenylacetamido 3 E propenyl cephalosporanic acid hydrolyzation into 7 amino 3 E propenyl cephalosporanic acid. Then, trans APRA was acylated with hydroxyethyl ester of 4 hydroxy D phenylglycine to obtain trans cefprozil.

以7 苯乙酰氨基 3 E 丙烯基 3 头孢菌素 4 羧酸为原料，在青霉素酰化酶作用下，首先酶法水解得到3 E 丙烯基 3 头孢菌素 4 羧酸，过滤固相酶，滤液调pH分离得到反式APRA固体；在青霉素酰化酶作用下，反式APRA再与对羟基苯甘氨酸乙二醇酯缩合，得到反式头孢丙烯；酶法合成所得的产品与进口反式头孢丙烯对照品一致。

The main production technique of DMC contains phosgene method, ester exchange method, and the carbonyl oxidized method.

碳酸二甲酯主要生产工艺有光气法、酯交换法和甲醇氧化羰基化法。

Diphenyl carbonate is an important carbonic ester, an important precursor for the synthesis of polycarbonate without using phosgene.

碳酸二苯酯是一种重要的有机碳酸酯，是非光气法合成聚碳酸酯的关键原料。

Objective: To observe the effects of the liposome composed by sucrose ester and phospholipids on the membrane phosphatide content of rabbit peritoneal macrophages.

目的：观察蔗糖酯与磷脂组成的脂质体对巨噬细胞膜磷脂含量变化的影响。

A salt or an ester of phosphoric acid.

这种酸把我的上衣烧了一个窟窿。

College of Environment and Energy Engineering, Beijing Polytechnic University, Beijing 100022, China ）Abstract The phosphoryl N → O migration reaction and ester exchange reaction on phosphorus of phosphoserine with methyl alcohol involving hexa-coordinate phosphorus intermediate 3 had been studied by MNDO method.

用MNDO方法对磷酰化丝氨酸仿生化反应机理中所形成的六配位磷中间体(3)可能的3个异构体的结构及其反应活性进行了研究。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。