查询词典 auxiliary

Chiral auxiliary controlled asymmetric reaction is one of the main methods in asymmetric synthesis.

手性助剂控制的不对称反应是不对称合成的主要方法之一。

Have you ever performed the auxiliary engine to combust heavy oil?

您做过烧重油的副机吗？

ESL Assistant will check for potential errors such as spelling mistakes, preposition confusion, confusable adjectives, word order, noun number, verb morphology, auxiliary choice, gerunds and infinitives.

ESL助理将检查可能存在的错误，如拼写错误，介词混乱，混淆形容词，词序，一些名词，动词形态，辅助选择，动名词和不定式。

Secondly, Chinese learners use much more the copular verb be, but less the auxiliary verb be.

第二，中国学习者多用系动词BE而少用助动词BE。

This paper introduces the method of simple conversion measuring and calculation for gear rack thickness with depthometer as prime measuring tool and Measuring Pin,measuring ball as auxiliary tool.

介绍了以深度尺为量具，以棒、球为辅件的齿条齿厚简易转化测量与计算方法。

In a similar way, using N,N\'-dibenzyl tartamide as auxiliary,-(2-methyl)allyl-2-chloro-phenyl-methyl azide, a vital intermediate of Repaglinide, can be prepared via asymmetric allylation of o-chlorobenzaldehyde in

产物经氧化和碘加成内酯化反应得到阿伐他汀中间体(3R，5S)-3-羟基-5-碘甲基戊内酯(10)；将N-苄基酒石酸二酰胺用于邻氯苯甲醛的不对称烯丙基化反应以较高光学收率得-甲基烯丙基-2-氯苯基-甲基醇

This work, concentrated on the asymmetric allylation of aldehydes controlled by different chiral auxiliaries prepared from rotational pure tartaric acid, can be divided into three parts.The first part aims to review the developments of chiral drugs and asymmetric synthesis, from which derived the present research topic backgrounds and works.Synthesis and applications of allylation from aldehydes are the second part of the thesis. By optimizing the reaction conditions, such as solvents, temperature, time and chiral auxiliaries like N,N\'-dibenzyl tartamide, N,N\'-p-dimethylphenyl tartamide, N,N\'-o-dimethylphenyl tartamide, N,N\'-o-dichlorophenyl tartamide, N,N\'-a-dinaphyl tartamide, N,N\'-dicyclohexyl tartamide and N,N\'-diphenyl tartamide, ideal experimenttal conditions are obtained according to HPLC monitoring, as well as the auxiliaries\' recoveries experiments. Starting from benzaldehyde and 3-bromopropaldehyde, N,N\'-dibenzyl tartamide is considered the best auxiliary in this reaction.

本文介绍了醛的不对称烯丙基化反应，以光学纯酒石酸为原料，研究了不同构型手性配体在醛的烯丙基化反应中的立体选择性，全文共分三部分十个章节：第一部分对当前手性药物和手性技术进行了概述，并由此展开了本文的研究背景和任务；第二部分为有机合成部分，对醛的不对称烯丙基化反应进行了深入探讨，以苯甲醛为原料对反应条件进行优化，在优化的反应条件下对制备的七种可回收手性酰胺配体(N-苄基酒石酸二酰胺、N-对甲苯基酒石酸二酰胺、N-邻甲苯基酒石酸二酰胺、N-邻氯苯基酒石酸二酰胺、N-a-萘基酒石酸二酰胺、N-环己基酒石酸二酰胺和N-苯基酒石酸二酰胺)进行筛选，优化配体回收实验条件，最终确定出N-苄基酒石酸二酰胺在苯甲醛的不对称烯丙基化反应中具有较大优越性，结晶回收的手性配体光学纯度保持不变。

By the hydraulic engineering modle experiment of Liaofang hydraulic project ,we adopted the energy dissipation method which took the T type pier as the auxiliary dissipater.

通过水工模型试验，廖坊水利枢纽工程采用T型墩为辅助消能工的消能形式，不但大大缩短了消力池的长度，而且得到较好的水流流态，满足了下游防冲要

Although like auxiliary soldiers the peregrine sailors did not receive citizenship until after 25 years' service, from the reign of Trajan or perhaps Domitian they were allowed to adopt Roman names upon joining the service.

尽管这些外国水手也只有服满25年军役才能获得罗马公民权，但自图拉真甚或图密善时代起，他们在加入军队时就可以起一个罗马名字。

Include pronoun, conjunction, preposition, auxiliary word, adverbial, exclamation, echoic word to wait.

包括代词、连词、介词、助词、副词、叹词、拟声词等。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。