亲电子的

According to the electrophilic substitution of α-Allocryptopin by ICl, it can be suggested that there are competitions of n-donors (such as N and O atom occurred in alkaloid or solvent molecules) with the conjugated π system in alkaloid molecule for iodine monochloride when charge-transfer complexes are formed, which may block the formation of pre-reactive π-complex intermediate, and thus suppress the electrophilic substitution.

这一方法标记过程简便，标记产物富集于有机相，易于进一步纯化，其放射化学纯度接近95%，标记率超过70%；ICl与α-别隐品碱的亲电碘化反应结果表明，生物碱底物或溶剂分子中的N、O等n电子给体可能与亲电试剂形成电荷转移络合物，竞争芳香亲电取代反应π络合物反应前体的形成，从而抑制碘化反应的发生。

This complex reaction was phenolic electronic substitution reaction, so reaction rate was related with the positive electricity of pro-electronic reagent, as well as the form of aromatic hydrocarbons. Rates of chlorination of phenol and 2-monochlorophenol were faster in alkaline water than that in weak acid water, so 2,4-dichlorophenol and 2,4,6-trichlorophenol formation concentrations increased with the reaction time.

该复合反应属于酚类电子取代反应，反应速率与亲电子试剂的阳电性以及芳香烃的形式有关，碱性水环境中氯取代苯酚和2-一氯酚的速率要快于在弱酸性水环境；随着pH的升高，2，4-DCP和2，4，6-TCP的生成浓度也不断增加。

The results of batch experiments showed that the anaerobic biodegradation kinetics of 2-CNB and 4-CNB by granular sludge were follwed by first-order reaction. The nitro groups of 2-CNB and 4-CNB were more easily attacked by electron than chlorines and they were reductively biotransformed to amino groups under anaerobic conditions. The acclimated anaerobic granular sludge, which could dechlorinate 4-chloroanline to aniline, showed that it had the ability of para-dechlorinating. The anaerobic biodegradating on pathway of 2-CNB and 4-CNB were suggested as follows:AbstractIn ZVI(zero-valent iron, Fe0)-reduction system, the nitro groups of 2-CNB and 4-CNB were reductively transformed to amino groups.

2分批试验结果证明，颗粒污泥降解2-CNB和4-CNB遵循一级动力学，在厌氧条件下，CNB发生序列的硝基还原与脱氯作用，苯环上的硝基比氯原子更容易受到亲电子攻击，发生还原反应生成氨基；所获得的颗粒污泥具有对位脱氯活性，可使4-CA进一步脱氯形成苯胺。2-CNB和4-CNB厌氧降解的建议性途径为： ZVI(Zero-valentiron)对2-CNB和4-CNB的作用主要是将苯环上的硝基还原为氨基；在ZVI与污泥共还原转化体系中，ZVI对氯代硝基苯的硝基转化具有一定的促进作用，但因ZVI对中间产物的吸附特性，终产物形成速率趋慢。

There are three different nucleophilic reagent respectively reaction with m-dinitrobenzene ramification at distint alkaline term:With the nitrobenzene 、 m-nirtobenzenesulfone sodium salt 、 2.4-dinitro chlorobenzene 、 m-dinitrobenzene for bottom thing, benzyl cyanide、 benzyl chloride、 benzyl chloropyridine、is a nucleophilic reagent reaction for under the different term proceeds a series reaction. At the same time ,discuss about the impact factor to nucleophilicity such as the number of attract electron group、 ability of attract electron and the nucleophilic substitution reaction part.

设计了三类不同的亲核试剂分别与活化芳环在不同的碱性条件下发生反应：以苄基氰、苄基氯化吡啶为亲核试剂，以硝基苯、间二硝基苯、间硝基苯磺酸钠、2，4-二硝基苄基氯为底物进行亲核取代反应；并且对亲核试剂的体积效应、溶剂效应对亲核性影响，底物上吸电子基团的数目、吸电子能力对亲电性的影响，以及亲核取代反应的发生部位受哪些因素影响进行探讨。

Understand the chemistry of alkenes and alkynes: nomenclature, electronic structures, sequence rule, cis-trans isomers, electrophilic addition reactions and mechanism, Markonikov's rule, conjugated dienes, rules of resonance forms.

A2 E3 了解烯类及炔类的化学性质：命名、电子结构，顺反异构物，亲电子加成反应及机制，马克尼可夫规则，共轭双键及共振式。

Using acetone as a photosensitizer,and N3· as an oxidant by pulse radiolysis method,the induced oxidation of cyclic-Phe-His in aqueous solution has been also reported in this paper,results similar to the photoionization of cyclic-Phe-His have been found.

而具有亲电子性的丙酮能在该环肽的苯丙氨酸残基的苯环上抽取电子，形成320nm和410nm的特征吸收峰，求出了自由基的有关动力学参数，并用脉冲辐解动态吸收光谱法印证了上述结果。

Fluorescence studies reveal that the self-coiling tendency of organic molecular driven by HLI strongly depends on the length of the chain and the donor and acceptor moieties linked by methylene chains approach each other because of the self-coiling to induce the fluorescence quenching and form the intramolecular exciplex or radical-ion pairs.

结果表明，在一定极性的溶剂体系中，具有一定碳链长度的有机分子在疏水亲脂作用的驱动下能够产生自卷现象，从而使长链两端的电子给体和电子受体相互靠近，发生电子转移，造成有机分子的荧光淬灭。

With the nitrobenzene、 m-chloronitrobenzene、 m-nirtobenzenesulfone sodium salt for bottom thing, Grinard agent is a nucleophilic reagent reaction for under the different term proceeds a series reaction.

以苄基氯化镁为亲核试剂，以硝基苯、间硝基氯苯、间硝基苯磺酸钠为底物进行亲核取代反应，探讨与芳环相连的吸电子基团的数目及吸电子性，对亲核取代反应的影响。

Thus further oxidized to more stable small molecule such as oxalic acid which is the inevitable product of aniline degradation due to the electrophilic character of ozone.

所以这些物质能进一步氧化分解成草酸等更稳定的的小分子。臭氧的亲电子性使草酸成为苯胺分解的必然产物。

The charge distribution result shows that the carbon is easy to get electron, and the nitrogen with lone pair electrons in the amino group is the electrophilic reaction site.

电荷分布方面，三聚氰胺分子上的碳原子易得电子为亲核试剂进攻点，而胺基上的氮原子因含孤对电子是亲电反应中心。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。