查询词典 allene

Furthermore, the mechanism of isomerization between propyne and allene mediated by HCo 〓 has been proposed.

此外，基于反应的自由能曲线，提出了HCo〓催化丙炔和丙二烯异构化反应机理。

The substituent on the allene group shows little effect on the yield of biboronic product.

而这类化合物，利用传统的催化方法是无法达到的。

Via comprehensive computations, the possibilities of vinylidene and allene intermediates were excluded, and the reaction mechanism was found to contain the following three steps:(1) gold-catalyzed cyclization to give the cyclic intermediate,(2) the cyclic intermediate undergoing a 1,3-H migration to give a more stable intermediate, with the assistance of water-cluster,(3) finially, the 1,2-H or 1,2-silyl migration occuring for generation of the observed product.

通过对各种可能的反应路径的进行计算和比较，排除了亚甲基卡宾和连二烯中间体的可能性，并确定该异构化反应机理包含以下三个步骤：（1）炔丙基吡啶反应在金催化条件下发生分子内的成环得到环状中间体；（2）环状中间体在水分子簇的协助下优先发生1，3-氢迁移反应，异构化得到更为稳定的中间体；（3）最后再进行1，2-氢迁移或是1，2-硅烷基团迁移即得到实验中所观察到的环异构化产物。

Wood ash is one example but chemical mordant such as allene alum are popular today.

但是当今流行的却是诸如明矾之类的化学媒染剂。在许多商店都有明矾出售。

A face-selective coordination of allene to the palladium center is proposed to account for the present stereoselectivity.

此加成反应的反应机构是经由I-B键氧化加成而启动的，并不是直接B-B键的氧化加成。

Allene oxide synthase is a key enzyme for JA biosynthesis.

丙二烯氧化物合成酶是茉莉酸生物合成的关键酶。

The predicted mechanisms for the two reactions are not in parallel with the reactions of CN with allene CH_2CCH_2 and methylacetylene CH_3CCH given in previous studies.

与深入研究的CN+CH_2CCH_2以及CN+CH_3CCH的反应体系相比，CP和CN反应体系的机理并不完全相似。

Although allene oxide synthase and hydroperoxide lyase are atypical cytochrome P450 family members involved in the synthesis of jasmonates and GLVs, respectively, it is unknown how these enzymes rearrange their hydroperoxide substrates into different products.

这些酶是两种物质的综合体，包括allene氧化物（allene oxide synthase，简称AOS）和过氧化氢酶（hydroperoxide lyase ，简称HPL），它能产生茉莉酸味和一种绿叶中含有的挥发物GLV，后者决定了蔬菜和水果的芳香特点。

According to somephysiological characteristic in Camptotheca acuminata and several specific functionsof CPT, allene oxide cyclase, a key enzyme of jasmonites pathway, was isolated fromCamptotheca acuminata; mealwhile, it was investigated whether themRNA expression of CaAOC was related to the content of CPT in Camptothecaacuminata.

根据喜树自身的一些生理现象和喜树碱在其中可能参与的一些特殊作用，我们主要从喜树中克隆了茉莉酸合成途径的关键酶丙二烯氧化物环化酶(allene oxide cyclase，AOC)基因并考察了其对喜树碱含量的影响，同时还进行了其他方面的相关研究。

HCo 〓-catalyzed hydroformylation and isomerization of allene and propyne Allene hydroformylation favors the linear anti-Markovnikov product in high regioselectivity both kinetically and thermodynamically. The origin of this regioselectivity comes from the enhanced stability of the η〓-allylic intermediate (η〓-CH〓CHCH〓 Co 〓.

HCo〓催化的丙二烯和丙炔氢甲酰化反应及异构化反应 HCo〓催化丙二烯氢甲酰化反应的区域选择性主要由不可逆的丙二烯插入步骤决定，动力学和热力学因素都有利于形成anti-Markovnikov中间物种(η〓-CH〓CHCH〓)Co〓，形成Markovnikov中间物种Co〓是不具有竞争性的。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。