烯烃

Based on the results and discussion of those experiments, a adoptable utilization method of the α-olefins were given

对于从焦化柴油分离得到的直链α烯烃的利用，特别是作为化工合成原料的利用，还没有人进行过比较深入的研究。

The catalytic efficiencies of a variety of fatty ketones, alicyclic ketones and heterocyclic ketones and the impact factors were reviewed in the paper.

本工作对各种脂肪酮、脂环酮、杂环酮对烯烃环氧化催化能力的大小及其影响因素进行了评述。

The alkene was identified by GC comparison with an authentic sample prepared by this same process.

被确定的烯烃的气相色谱比较一个真实的样本编制的同一过程。

The new catalyst for preparing base oil of lubricant by polymerization of α-alkene was studied.

对α-烯烃聚合制备润滑油基础油的新型催化剂进行了研究。

A flammable colorless gaseous alkene; obtained from petroleum and natural gas and used in manufacturing many other chemicals.

一种无色易燃的气态烯烃，从石油和天然气中提取，用于制造其他许多化学品。

The alkene chain and H2Se were detected respectively by a series of experiments to support the new mechanism.

通过一系列实验，我们分别检测了烯烃和硒化氢气体，证实了我们所提出的生成机理。

The speed of electrophilic addition reaction of Alkene is well-connected to the nature of substituting group on C=C.

对于烯烃的亲电加成反应速度，与C=C上直接连接的取代基的性质有关。

A one-step method for the synthesis of aromatic indolizine derivatives byintramolecular 1,5-dipolar cyclization reaction of 2-(2-arylethenyl)pyridinium N-ylidesin the presence of an oxidant has been studied for the first time. In the presence ofelectron-deficient olefins, however, 2-(2-phenylethenyl)pyridinium N-ylides underwent1,3-dipolar cycloadditions and then aromatized in situ by TPCD to produce indolizinederivatives, indicating 1,3-dipolar cycloaddition proceed more readily than 1 ,5-dipolarcyclization in these conditions. Pyridinium disubstituted N-ylides, readily obtainedfrom corresponding pridinium and β-chlorovinyl ketone, underwent thermalintramolecular 1,5-dipolar cyclization to give indolizine derivatives easily.Indolizinecarbaldehyde derivatives were synthesized starting from 2-pyridinecarbaldehyde in four-steps involving 1,3-dipolar cycloaddition reaction.

本文首次研究了2-(2-芳基乙烯基)吡啶N-叶立德在氧化剂存在下的分子内1，5-偶极环化反应，采用一锅法合成了中氮茚衍生物；研究了这些N-叶立德的1，5-偶极环化和1，3-偶极环加成反应的选择性，发现当有缺电子烯烃存在时，优先进行1，3-偶极环加成反应，而不再发生分子内1，5-偶极环化反应；由β-氯乙烯酮方便地得到了烯丙基N-叶立德，他们在加热时进行分子内1，5-偶极环化反应而得到中氮茚衍生物；由2-吡啶甲醛为起始原料，通过1，3-偶极环加成反应等四步反应，得到了重要的中氮茚甲醛衍生物，这些反应都具有条件温和和操作简便的特点，是合成中氮茚衍生物的新方法。

The content of alkenes in FCC gasoline exceeding the standard and the shortage of propylene are the two problems in Chinese petrochemical industry.

FCC 汽油烯烃含量超标和丙烯短缺是我国石油化工行业面临的两个问题。

Catalytic thermal cracking technology, making use of VGO and residue as feedstock and solid acid catalyst which consists of ZSM-5 zeolite as major activity components, is a new process of producing low-carbon olefines composed of ethylene and propylene mainly under certain condition in FCC plant.

催化热裂解技术是以减压馏分油和渣油为原料，使用以ZSM-5分子筛为主要活性组元的固体酸催化剂，在催化裂化装置上，在一定的工艺条件下生产乙烯和丙烯为主的低碳烯烃的一项新工艺。

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。