烯烃

It is indicated that 35USD/bbl of oil price is the competitive key point for olefin project from naphtha,coal and natural gas.

指出在考虑融资方案影响的情况下，原油价格35美元/bbl为煤、天然气制烯烃项目与石脑油制烯烃项目相竞争的节点。

The MTO process of alkene preparation,including ethylene,propylene,butene,by the synthesis of methanol from natural gas was discussed.

介绍了国内外天然气制烯烃技术发展概况，论述了以天然气为原料经合成甲醇进一步生产烯烃的 MTO工艺。

"Rare in nature, olefins are obtained by the cracking of petroleum fractions at high temperatures. The simplest ones (ethylene, propylene, butylene, butadiene, and isoprene) are the basis of the petrochemical s industry."

烯烃在自然界很稀少，但在石油裂解成汽油过程中可大量生成，低级的单烯烃已成为庞大的石油化学工业的基础。

"Rare in nature, olefins are obtained by the cracking of petroleum fraction s at high temperatures. The simplest ones (ethylene, propylene, butylene, butadiene, and isoprene) are the basis of the petrochemicals industry."

烯烃在自然界很稀少，但在石油裂解成汽油过程中可大量生成，低级的单烯烃已成为庞大的石油化学工业的基础。

"Rare in nature, olefins are obtained by the cracking of petroleum fractions at high temperatures. The simplest ones (ethylene, propylene, butylene, butadiene, and isoprene) are the basis of the petrochemicals industry."

烯烃在自然界很稀少，但在石油裂解成汽油过程中可大量生成，低级的单烯烃已成为庞大的石油化学工业的基础。

When used in LAB complex unit with multi-step hydrogenation process,DSH-1 selective hydrogenation catalyst,which contain noble metal Pd,can transmit diolefin s to olefins effectively,and has good activation and selectivity.

DSH -1型含贵金属Pd双烯选择性加氢催化剂与多段加氢工艺结合，应用于脱氢法生产直链烷基苯的联合装置中，能有效地将脱氢过程产生的双烯烃转化成单烯烃，具有很好的反应活性和选择性，且操作弹性大，工艺过程简单。

Through mechanism analyzing on the process of producing HMT , it was known that because the resistance of isobutylene was small ,the yield of outgrowth in such a reaction system was little and the yield of reaction was as high as 86%. 2,3-dimethyI-butene-2 had the biggest resistance and lowest yield of reaction of 18%. 2,3-dimethyl-butene-l had bigger resistance than isobutylene and more outgrowth than isobutyles but its yield of reaction could reach 70%.

通过对上述三种烯烃合成HMT的研究可知，由于新己烯位阻小，反应中副反应少，收率高达86％：而2，3—二甲基—丁烯—2的位阻最大，反应中副反应最多，反应收率最高仅为18％；2，3—二甲基—丁烯—1的位阻比新己烯大，反应副产物比新己烯多，但反应收率仍可达70％。

The effect of zeolites ion-exchanged by transition metals on thermal catalytic cracking reaction is studied. The product distributions of the cracking reactions catalyzed by theβor ZSM-5 zeolites exchanged with transition metals are different from that catalyzed by corresponding Hzeolites, which means the mechanism of cracking reactions has varied. Group Ⅷ metals Fe, Co, Ni and Cu, Zn are shown to be of strong catalytic activity of oxidative dehydrogenation, while Ti and Cr are not of oxidative activity. Catalyzed by zeolites or catalyst containing Ag, conversion of thermal catalytic cracking reactions and the yield of ethylene increase while the yield of propylene does not decrease. Silver can not only promote the formation of carbonium ion, but also convert carbonium ion into free-radical via redox reaction. The weak adsorption of olefins on silver reduces the occurrence of hydrogen transfer and dehydrogenation. As a result, the yield of light olefins is favored by silver in the catalyst.

采用过渡金属交换的分子筛作为催化剂，进行催化热裂解制取乙烯的反应，研究发现，在β沸石分子筛和ZSM-5分子筛中引入过渡金属后，催化热裂解反应的产物分布与相应的氢型分子筛相比有了较大的变化，说明过渡金属的加入对于催化热裂解反应的机理具有影响，Ⅷ族金属如Fe、Co、Ni和第Ⅰ、Ⅱ副族Cu、Zn表现出较强的氧化脱氢活性，产物中氢气、焦炭的产率很高，Ti、Cr则未表现出氧化作用：分子筛及催化剂中引入银后，催化热裂解反应的转化率和乙烯的产率有了提高，丙烯产率没有很大的变化，说明银在催化热裂解反应中能够促进正碳离子的生成，又有可能通过氧化-还原作用部分改变反应机理，促进了自由基的生成，并且由于银对烯烃的吸附很弱，其氢转移反应和脱氢、加氢活性比较低，有利于烯烃产率的提高。

As an essential component of the Baylis-Hillman, alkenes especially activated alkenes are a kind of very important building blocks in organic synthesis, and have been applied in various fields.

作为Baylis-Hillman反应的重要组成部分，烯烃特别是具有一定活性的烯类化合物，由于它们本身的结构特征，具有与一般烯烃不同的独特的性质，是非常重要的有机合成中间体。

The content of conjugated dienes in petroleum products is determined by ultraviolet spectrophotometry.

在化学反应－气相色谱法联合测定含烯汽油中共轭二烯烃质量分数的基础上，建立了用紫外分光光度法测定油品中的共轭二烯烃的含量。

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。