环烯

In another direction, the radical cyclization of thioimide with acylsilane produced simple cyclization product in low yield without expected enol silyl ether compound.

对於硫醯亚胺与矽基酮的自由基反应，则是得到低产率的简单环化产物，而不是预期的烯醇矽醚化合物。

Additionally, the quantum chemical study on the isomeriaation mechanism of the enol ester of 2-acyl-l,3-cyclohexanedione was performed, which was discovered by Yang when he synthesized the derivate of 2-acyl-l,3-cyclohexanedione.

第三部分工作是对杨定亚在合成2-酰基-1，3-环己二酮类化合物的衍生物时意外发现的烯酯异构化反应机理进行了研究。

Over the years, Masson's food additive brand -"Silver Valley" has been at the forefront of China Food Additive Industry forefront of the reform In 1984, the first in the domestic market development and production of soybean products for human consumption antifoamer; in 1988, took the lead in the domestic market development and production of edible spices - cyclopentyl enol methyl ketone; in 1989, took the lead in the domestic market to develop speed-fat cake oil; In 1992, the first in the domestic market development and production of ice cream and beverage emulsion stabilizer; in 1999, introduced the internationally advanced level molecular distillation Monoglyceride domestic exclusive CPP realize industrial production

多年来，美晨公司的食品添加剂品牌--"银谷"一直站在中国食品添加剂工业改革的潮头 1984年，率先在国内市场开发生产豆制品食用消泡剂；1988年，率先在国内市场开发生产食用香料--甲基环戊烯醇酮；1989年，率先在国内市场开发速发蛋糕油；1992年，率先在国内市场开发生产冰淇淋和饮料乳化稳定剂；1999年，推出具有国际先进水平的分子蒸馏单甘酯，在国内独家实现CPP工业化生产

The properties of single-chain and pauci-chain polystyrene microspheres and recent results on the electron microscopy and selected area electron diffraction of single-chain monocrystals of polyethylene oxide, isotactic polystyrene, cis-1, 4-polybutadiene and guttapercha are presented and discussed.

介绍和讨论了单链和寡链聚苯乙烯玻璃体微球的性质以及聚环氧乙烷、全同立构聚苯乙烯、顺-1， 4-聚丁二稀、反-1， 4-聚异戊二烯单链单晶电子显微镜和选区电子衍射观察的最新结果。

ZnO nanorings were prepared on a large scale by a facile solution-based method at 70 ℃ for 5 h via hexamethylenetetramine(C6H12N4) and Zn(NO3)2·2H2O as the raw materials in the presence of surfactant PAM-CTAC.

以六次甲基四胺(Hexamethylenetetramine， C6H12N4)和水合硝酸锌[Zn(NO3)2·2H2O]为原料，表面活性剂聚丙烯酰胺-氯化二烯丙基二甲基铵为形貌控制剂，采用液相沉淀法合成了ZnO纳米环。

Theoretical investigation of the solvent effects on the mechanism of the reaction of pentafulvenone with hydrocyanic acid to produce the main product of acid of type b was carried out at B3LYP/6-311+G** level via the conductor-like polarizable continuum model.

在B3LYP/6-311+G**计算水平上，采用导体极化连续模型研究了溶剂化效应对6-亚甲基环戊二烯酮与HCN反应生成主要产物b类酸的反应机理的影响。

Theoretical investigation of the solvent effects on the mechanism of the reaction of pentafulvenone with hydrocyanic acid to produce the main product of acid of type b was carried out at B3LYP/6-311+G(superscript **) level via the conductor-like polarizable continuum model.

在B3LYP/6-311+G计算水平上，采用导体极化连续模型研究了溶剂化效应对6-亚甲基环戊二烯酮与HCN反应生成主要产物b类酸的反应机理的影响。

Starting with the readily available isatin, two designated key cyclization precurors 25 and 26 were synthesized respectively by 5 steps and 6 steps reactions ,with Wittig reaction and Corey-Chaykorsky reaction as key steps.

以商品可得的吲哚醌为起始原料，分别经过5步和6步以Wittig烯烃化，Corey-Chaykorsky反应为关键步骤的合成路线，得到2个用于的环合反应的前体亚胺25和26。

In the second chapter, the mechanism of the gold-catalyzed cycloisomerization of bromoallenyl ketone was investigated and discussed.

在第二章中，通过理论计算对金催化的溴代连二烯酮环异构化反应的机理进行了研究和讨论。

The preparation and characterization of mono-and bispenta-phenylcyclopentadienyl lutetium chlorides were reported.

本文介绍高空间位阻的五苯基环戊二烯基氯化镥的合成及鉴定。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。