环烯

Liquid-phase epoxidation of allyl chloride with hydrogen peroxide was carried out over Ti-MWW, a novel titanosilicate with the MWW structure, to synthesize epichiorohydrin selectively and effectively. Ti-MWW proved to be superior to the conventional TS-1 catalyst in both catalytic activity and product selectivity. Ti-MWW prefers aprotic solvents of acetone and acetonitrile, both of which can restrain the solvolysis of epichiorohydrin, whereas TS-1 favors a protic solvent of methanol.

研究了具有MWW结构的新一代钛硅分子筛Ti-MWW催化剂对烯丙基氯液相环氧化高效合成环氧氯丙烷的催化性能结果表明，Ti-MWW的催化活性以及产物选择性均优于传统的钛硅分子筛TS-1，对于Ti-MWW，合适的溶剂为非质子性溶剂丙酮和乙腈，在该溶剂中环氧化物不易发生溶剂化开环反应；而对于TS-1，合适的溶剂是质子性溶剂甲醇，但甲醇可导致醇醚副产物的生成。

Using poly (4-merhylpentene-l) as a membrane material and cyclohexane, irich-loroethylene, tetrachloroethylene, mixture of cyclohexane and trichloroethylene or tetrachloro-ethylene as solvents, the solution were cast to form homogeneous dense membranes, and the crystalline properties and surface morphology were investigated by DSC and TEM.

以聚4-甲基戊烯-1为膜材质，分别以环己烷、三氯乙烯、四氯乙烯、环己烷/三氯乙烯及环己烷/四氯乙烯为溶剂，研究了这些溶液浇铸膜的结晶性质和表面形态。结果表明，溶剂对PMP的相对溶解能力和挥发速度同所成膜内PMP的结晶形式和结晶度密切相关；不同溶剂体系的PMP溶液浇铸膜的表面形态也不尽相同。

The invention comprises a cyclopalladated catalyst with axial chiral binaphthyl backbone containing phosphine ligand as well as the synthesis thereof, and the application of the catalyst with cyclopalladated catalyst with axial chiral binaphthyl backbone containing phosphine ligand with a similar structure to the hetero atom norbornadiene ring cleavage reaction through an asymmetric catalytic organic boron agent.

本发明包括一类具有轴手性联萘骨架含膦配体的环钯催化剂及其合成，以及其与具有类似结构的轴手性联萘骨架含膦配体的环钯催化剂在不对称催化有机硼试剂对杂原子降冰片二烯开环的应用。

New progress on the catalytic epoxidation of cyclohexene was reviewed.

综述了环己烯催化氧化法合成环氧环己烷的最新研究进展。

Under the optimized conditions the conversion of cyclohexene and the selectivity of epoxycyclohexane could reach up to 91.4% and 86.3%, respectively.

在此条件下环己烯的转化率可达91.4%，环氧环己烷的选择性达86.3%。

The results reveal that the supported catalyst has high catalytic activity and good selectivity of epoxide for the epoxidation of cyclohexene and styrene, respectively.

上述结果表明该负载催化剂对环己烯和苯乙烯的空气环氧化具有很高活性和环氧化物选择性。

To enable the fabrication of thermally stable ultralow dielectric constant film, specific precursor materials are used, such as, cyclic siloxanes and organic molecules containing ring structures, for instance, tetramethylcycloterasiloxane and cyclopentene oxide.

为了能够制造热稳定超低介电常数材料，使用特定的前驱物材料，例如环硅氧烷和例如四甲基环四硅氧烷和环戊烯氧化物这样包含环状结构的有机分子。

In this research FGA was synthesized through total ten steps such as epoxidation via H2O2, carbonyl protection, LiAlH2 reduction、carbonyl deprotection, epoxidation and ring opening with HF, oxidation, bromination and debromination et al.

设想通过对蕃麻二烯物进行H2O2环氧化、羰基保护、LiAlH4还原、羧基脱保护、溴羟环氧、HF开环、氧化、上溴脱溴等一系列反应得到FGA。

In the second part of this thesis, a formal [2+2] cycloaddition ketenes and dialkyl azodicarboxylates was studied. We found that by adjusting the substituents in the diazenes, the reaction mode can be completely switched, and furnish four-membered-ring products, aza-b-lactams, the enantioselectivity was up to 91%.

经研究发现，通过对偶氮化合物取代基团的改变，我们可以实现[4+2]环加成反应到[2+2]环加成反应的转变，在手性氮杂环卡宾的作用下，对具有各种取代基的烯酮都可以很好的产率得到氮杂b-内酰胺，其对映选择性最高可以达到91%。

The polymer also had better moisture resistance because of the hydrophobic nature of DCPD and naphthyl groups.

由于憎水性的萘环结构和环戊二烯环的引入，固化产物也表现出良好的耐水性。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失