substitution

英[sʌbsti'tju:ʃn]美[sʌbsti'tju:ʃn]

n.[C,U]
代理，替换，交换

形容词：

同：	[n.] commutation, exchange, permutation, replacement

Like the amino group, the phenolic group powerfully activates aromatic rings toward electrophilie substitution, and in essentially the same way
对于亲电取代反应，酚基基本上以同氨基一样的方式使芳环强烈活化。收藏
Severe steric effects at the reactive carbon would impede the substitution
大的立体效应阻止在碳上的取代。收藏
Most direct substitution of groups bound to an aromatic nucleus is limited to diazonium salts
大多数连于芳核能被直接取代的基团仅限于重氮盐。收藏
amines can engage in nucleophile substitution reaction with alky
胺能参加与卤代烷的亲核取代反应。收藏
In cryptography,a cipher produced by a composition of a number of substitution and transposition ciphers.
密码学中，由替代密码和置换密码结合使用而构成的一种密码。收藏

　　　 more...

an event in which one thing is substituted for another
- the replacement of lost blood by a transfusion of donor blood
[同] permutation, replacement, substitution, switch, transposition
the act of putting one thing or person in the place of another:
- he sent Smith in for Jones but the substitution came too late to help
[同] commutation, exchange, substitution

热点链接

历史查询

[清空历史] [更多]