查询词典 oxonium

Based on density functional theory calculation with periodic boundary conditions, the possibility of the direct coupling of methanol into ethene by oxonium ylide mechanism was investigated.

采用基于周期性边界条件的密度泛函理论研究了HSAPO-34分子筛上甲醇通过氧鎓叶立德机理直接耦合生成乙烯的可能性。

It is thus concluded that the methanol to olefin reaction cannot follow the oxonium ylide mechanism.

因此，甲醇制烯烃催化过程不可能遵循氧鎓叶立德机理。

Phosphorous, sulfur, ammonium and oxonium ylides have been widely utilized in orgaic synthesis.

磷，硫，铵基，氧叶立德等已经广泛的在有机合成中得到应用。

It have been observed that oxonium ion reacted with water more easily than with THF. So water could be used as ceasing reagent to control the molecular weight of the polymer.

本文还对四氢呋喃、环氧丁烷和环氧乙烷阳离子开环聚合反应中，分子内尾咬、扩环这一典型的副反应进行了理论研究。

Thepotential energy surface of these reactions were plotted, and the energy barrier of the reaction between THF and secondary oxonium ion was determined to be 182.0.116 kJ/mol.

本文进一步对四氢呋喃阳离子开环聚合反应过程中，氧鎓离子与水反应的机理进行了分析。

As to butylene oxide and secondary oxonium ion the barrier was determined to be 92.672kJ/mol.The reaction between oxonium ion and water in the polymerization of THF was investigated too.

结果表明，与四氢呋喃单体相比，水更容易与氧鎓离子发生反应，因此可以用水作为中止剂，来控制聚合产物的分子量。

The transition states of the reaction between THF、 butylene oxide and secondary oxonium ion were acquired. By using frequency analysis and inner reactioncoordinate analysis the rationality of these transition states were affirmed.

分别对四氢呋喃和环氧丁烷，绘出了链增长反应的势能面曲线，得到四氢呋喃链增长反应的活化能为116.749kJ/mol；环氧丁烷链增长反应的活化能为92.672kJ/mol。

By using density functional theory B3LYP/6-311G++method, the geometric configuration was optimized for tetrahydrofuran、butylene oxide、 secondary oxonium ion and tertiary oxonium ion. And parameters about the electronic structure, bondlength, energy of frontier orbital of these species were determined.

采用DFT中的B3LYP/6-311G++方法对四氢呋喃和环氧丁烷单体、仲氧鎓离子以及叔氧鎓离子进行了几何构型的全优化，确定了各个构型的电子结构、键长和前线轨道能量等参数，并运用前线轨道理论从微观层次上分析了四氢呋喃和环氧丁烷的阳离子均聚反应机理。

The calculated results indicate that the energy bathers for the formation of dimethyl ether and trimethyl oxonium ion inside HSAPO-34 zeolite are 1.68 and 0.93 eV, respectively. The suggested intermediate oxonium ylide is very unstable and the energy barriers for the formation of C-C bond are over 3.0 eV by concerted pathway.

结果表明，二甲醚和三甲基氧鎓离子在HSAPO-34分子筛上的生成能垒分别为1.68和0.93eV，中间体氧鎓叶立德不能稳定存在，同时表明C-C键通过协同反应形成的能垒均超过3.0ev。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！