本文根据实验事实,阐述了烷基的负诱导效应.In this paper, negative induction effect of alkyl is discussed base on the experiment facts.季铵盐中烷基的转移具有较好的选择性,其优先顺序为:苄基>伯烷基>仲烷基.Excellent selectivity in alkyl transfer was noted in the sequence of Ph...
a dull lackluster life沉闷、黯淡的生活lackluster eyes用没有光彩的眼睛And returns will be lackluster for the majority of firms left out of the best deals.当大多数这样的公司都被排除在理想的投资目标外后,你又能期待怎样的预期呢.He has already been blamed for his party's...
I need a new watch strap.我需要一条新表带。Nancy gripped the strap of her beach bag...南希抓住了自己沙滩包的带子。Crafting a leather strap is completed by laser - marking of the lining.在内衬上用激光刻上标记.She pulled the strap of her nightgown onto her...
She became quite a notable director in the thirties and forties.她在三四十年代成了一位名导演。Her mother had bundled all her Forties clothes up and burnt them.她母亲把她四十几岁时穿的所有衣服都包起来烧掉了。I went on competing till I was in my middle forties....