烯烃

The osmium-catalyzed asymmetric dihydroxylation of olefins provides one of the most effective methods for the preparation of vicinal diols. Almost all kinds of olefinic substrates can be transformed to the corresponding diols by means of AD reaction. The chiral osmium catalyst is generated in situ by the chiral ligand complexing with OsO〓 in the reaction.

手性锇催化剂催化的烯烃不对称二羟基化反应是合成手性邻二醇最有效的途径之一，可以将几乎所有类型的烯烃转变成相应的手性邻二醇，因此广泛地应用于药物、天然产物以及精细化工产品的合成。

Selected novel olefinic orthoesters, may be copolymerized with other olefins using certain late metal transition catalysts, to form novel polyolefins containing orthoester pendant groups.

利用某些后过渡金属催化剂，可以使选择的新颖烯烃原酸酯与其它的烯烃共聚合，以形成含原酸酯侧基的新颖聚烯烃。

In addition, the invention further relates to a catalyzer combination used for polymerizing a conjugated dialkene monomer and the anions of an optional mono-vinyl aromatic hydrocarbon into a polydiene polymer having high and medium vinyl content. The catalyzer combination comprises an organolithium compound used as an anionic polymerization initiator, at least an alkali metal alkoxide compound expressed by the formula as a structure regulator.

此外，本发明还涉及一种用于将共轭二烯烃单体和任选的单乙烯基芳烃阴离子聚合成具有中高乙烯基含量的聚二烯聚合物的催化剂组合物，其包含作为阴离子聚合引发剂的有机锂化合物，和作为结构调节剂的至少一种式所示的碱金属醇盐化合物。

The catalyst combined with MAO or Al(i-Bu_3, AlEt_3 to form copolymerization active species, which was responsible for copolymerizing the ethylene andα-olefins to prepare branched polyethylene.

二酮锆/MAO Al(i-Bu_3、AlEt_3可以形成乙烯与α-烯烃的共聚活性中心，催化乙烯与特定链长的α-烯烃共聚得到了支化聚乙烯。

The research development of the reaction of light alkenes from CO 2 hydrogenation and the supply of cheap hydrogen is discussed.

对CO_2加氢合成低碳烯烃反应进行了热力学分析，就近年来关于CO_2加氢合成低碳烯烃反应及廉价氢的供给的研究进展进行了综述。

This novel reagent was treated with LDA to produce polystyrene-supported a-seleno carbanions, which reacted with alkyl halides and epoxides, followed by stereospecific selenoxide syn-elimination to give olefins and allylic alcohols respectively.

它与LDA反应形成α—硒基稳定的碳负离子，再与卤代烃或环氧化合物发生α—烷基化反应，烷基化后的树脂可以在30%的双氧水中进行氧化-消除，以良好产率和较高纯度合成了取代烯烃或烯丙基醇。

Zinc diamyl dithiocarbamate antioxidant showed good synergism with antimony diakyl dithiocarbamate antiwear additive in improving the oxidation stability of modified soybean oils. The incipient oxidation temperature and induction period time of genetically modified soybean oils were improved significantly by adding polyalphaolefin and additives, and they were even better than that of the synthetic base oil PAO with the same additive formulation.

结果表明，改性大豆油的不饱和脂肪酸含量越高，其氧化安定性越差；抗氧剂二戊基二硫代氨基甲酸锌和抗磨剂二烷基二硫代氨基甲酸锑在改性大豆油中均表现出了良好的抗氧协同性能，尤其在基因改性大豆油中，聚-α-烯烃和添加剂的复配使其起始氧化温度和氧化诱导时间均超过了相同配方的聚-α-烯烃油样。

Urea adduction, in which i-propanol and water was used as mixed solvent, was introduced to separate α-olefins from coker kerosine distillate 220-320℃.

研究结果表明，采用异丙醇尿素水溶液脱蜡工艺，可从焦化柴油中成功分离得到直链α烯烃和直链烷烃，焦化柴油可作为C〓-C〓直链α烯烃与直链烷烃的一个重要来源。

However, there is little work reported on the separation ofα-olefins and other internal olefins.

对于不同烯烃之间的分离，特别是沸点相近的同分异构体烯烃之间的分离，国内外报道均不多。

The kinetics model was gotten based on the alkyl mechanism, light olefins re-absorption and re-reaction. The kinetics experiment is carried out over the selected Fe-Mn-K catalyst, and the kinetics model parameters is got base on the kinetics experiment data. The parameters explain the reaction results that the carbon monoxide content is high, the methane content is the biggest of the hydrocarbon products and the olefin content is bigger than the corresponding alkenes content.

本文同时对该反应的反应机理和动力学进行了研究，以烷基机理为基础，建立了考虑烯烃再吸附和二次反应的动力学模型，并在选定的催化剂上进行了相应的动力学实验，结合动力学实验数据计算得到了相应的动力学模型参数，模型参数值解释了反应产物中CO的含量较高，以及烃类产物中CH4含量最高和烯烃含量大于相应的烷烃含量。

He and Nina moved to California and lived at 2005 Ivar Street, Apt.

他和Nina搬到加州，并在2005年伊瓦尔街，公寓生活。

Droperidol （ potently inhibits transfected HERGchannels and this is the probable mechanism for QT prolongation.

氟哌利多有效地抑制了转染的 HERG 钾通道，可能是 QT 间期延长的机制。