查询词典 acetacetic ester

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. The three isomers structures of 3 were discussed in detail based on the calculation results.

谭波用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。

Therefore, N-phosphoamino acids could be used as models in the study of reactions of the phosphoryl group in the life process.First of all, a series of model N-phosphpoamino acids were synthesized. And their ester exchange reaction on the phosphorous center was studied by ~(31)P NMR, HPLC, ESI-MS and ESI-MS/MS.

首先，本论文从氨基酸角度研究磷化学，合成了一系列模型化合物N-磷酰化氨基酸，利用~(31)P NMR技术研究了磷上酯交换反应，发现α-氨基酸对于磷原子存在着手性选择现象，并且这种手性选择的差异随α-氨基酸种类的不同也有所区别。

And the efficiency of the systems treated with more phthalate ester indicated slightly higher.

酞酸酯投加量多的系统的去除率稍高于投加酞酸酯较少的系统。

Acetylcholinesterase in the nervous system of insects is one of the most important enzymes, in the central and peripheral nervous system and the acetylcholine receptor involved nerve-nerve and nerve-muscle synaptic transmission between the action potential, and its main function is catalyzed hydrolysis cationic neurotransmitter acetylcholine. At present, in the natural products active material, the AChE ester moves the spot inhibitor physostigmine was studied clearly.

乙酰胆碱酯酶(Acetylcholinesterase，AChE)是昆虫神经系统中最重要的酶系之一，在中枢及外周神经系统中与乙酰胆碱受体一起参与完成神经-神经及神经-肌肉突触之间动作电位的传递，其主要生理功能是催化水解阳离子性神经递质乙酰胆碱。

NMR and ESI-MS techniques were used to study the interactions between diperoxovanadates and small organic molecules such as pyridine, imidazole, arginine, picoline ester, and picoline amide. Spectroscopic methods were established to explore this type of interactions.

在合成数种双过氧钒化合物的基础上，利用多种NMR技术结合ESI-MS等谱学方法系统研究了双过氧钒化合物和咪唑、吡啶、取代吡啶、精氨酸、皮考啉酯以及皮考啉酰胺等有机配体的相互作用，建立了一套适合研究过氧钒化合物与有机小分子相互作用的谱学方法。

Hydroxylcarveol(3) and its ester derivatives were synthesized from α-pinene(1), and their structures had been identified by IR, MS, 1H NMR and 13C NMR analysis.

以α-蒎烯(1)为原料，合成了8-羟基别二氢葛缕醇(3)及其甲酸酯(4)、乙酸酯(5)和丙酸酯(6)，并用IR、MS、1H NMR及13C NMR分析对它们的结构进行了表征。

In the second part of this dissertation, we studied the stereoselectivity of the Pictet-Spengler reaction of D-tryptophan methyl ester with piperonal and the synthesis of tadalafil.

在本论文的第二部分，我们研究了D-色氨酸甲酯和胡椒醛发生Pictet-Spengler反应的立体选择性和他达那非的合成。

We discovered that the best stereoselectivity of the Pictet-Spengler (cis/trans=92:8) was obtained, when the reaction of D-tryptophan methyl ester II-33 with piperonal II-34 in acetic acid was catalyzed by benzoic acid at room temperature.

我们发现室温下在冰醋酸中，D-色氨酸甲酯II-33和胡椒醛II-34在苯甲酸催化下，发生Pictet-Spengler反应的立体选择性最高， cis：trans的比例为92： 8。

The Pictet-Spengler reaction of D-tryptophan methyl ester hydrochloride II-42 with piperonal II-34 in various solvents was extensively studied. The best stereoselectivity (cis/trans=99:1) was obtained using nitromethane or acetonitrile as the solvent.

我们研究了在不同溶剂中，D-色氨酸甲酯盐酸盐II-42和胡椒醛II-34发生的Pictet-Spengler反应的立体选择性，发现当分别用硝基甲烷和乙腈做溶剂时反应的立体选择性达到最高， cis：trans的比例为99： 1。

The invention publishes a new craft for distilling pamade from raw oil in method of short chain fatty acid and ester as acetone in pomade picked-up technique field.

本发明公开了属于油脂抽提技术领域的一种直接以短链脂肪酸酯作为溶剂抽提含油原料中油脂新工艺。

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。