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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。

We usedit as the macroinitiator,(copper monochloride/pentamethyldiethylenetriamine as thecatalyst), to initiate the atom transfer radical polymerization of Fx-14, thus weobtained a fluorine and silicone containing triblock copolymer.

以此聚合物为原子转移自由基聚合中的大分子引发剂，引发含氟单体Fx-14进行原子转移自由基聚合，得到了含氟、含硅的三嵌段共聚物。

The molecular structure of 9,9 '-spiral Spirobifluorene has a very characteristic , which has two planar aromatic structure .they were connected through the only carbon atom and form the mutually perpendicular and structural stability of the cross-plane.

9，9'-螺双芴的分子结构非常有特点，两个具有平面结构的芳香环，通过唯一的碳原子连接构成相互垂直、结构稳定交叉平面。

From the geometry and natural charges analysis,the oxygen atom of O14 was considered to have much influence on the structure and properties of the title compound.

通过对其优化构型及自然原子电荷分析，证明O14原子对DNTF的结构和性质的影响最大。

An atom has the same number of electrons as protons ,so the amounts of negative and positive charge balance.

一粒原子具有相同数量的电子和质子，因此，负和正电荷的数量平衡。

And ever and again, her wandering glance reverted to the frail atom of humanity nestling by her side.

她一次又一次地回过头来看着蜷缩在身边的那个脆弱的小生命。

The bulky ortho-brominated aryl groups are implanted to create nonplanarity around amino center. Thus, the effective conjugation length to the protonation site is shortened and the energy gap between neutral and protonated forms is narrowed. The protonation can only occur at the nitrogen atom of the benzothiazole and the temperature variation disturbs the equilibrium between the neutral and monocation and the reverible thermochromic effect can thus be achieved.

在邻位的位置引入立体阻碍大的溴原子，进而控制质子化过程的酸碱平衡只发生在 benzothiazole 上的氮原子上，企图达到只有中性分子，与单阳离子两种稳定的形式存在，经由外界的刺激下，例如温度或酸的量的改变，促使逆反应的发生，而达到热致变色的效果。

The neutron bomb seems quite mysterious to ordinary people, in fact, it is a special kind of H_bomb. Since Chinese has already possessed atom and H_bomb , it is quite logical and natural for it to master the neutron bomb technology through its own efforts over a reasonable period of time.

中子弹一般人看起来似乎神秘，实际上是一种特殊的氢弹，中国作为掌握了原子弹、氢弹技术的国家，经过短时间的努力，就掌握了中子弹的技术，这是顺理成章、水到渠成的事。

On the other hand, if a neutron is emitted the product of the reaction is not a known atom.

另一方面，如果被排出的是中子，这个化学反应的产物则是一种未知的原子。

A siloxane precursor containing azobenzene dye and its synthesis are disclosed. In structural formula, R is nitrile, nitryl or chlorine atom.

本发明公开了一类含偶氮苯染料的硅氧烷先驱体，其结构通式如式1，其中，R为氰基、硝基或氯原子。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。