过渡态

The mechanism of ring-opening cationic polymerization reaction of tetrahydrofuran and butylene oxide was analyzed on the basis of electronic microstructures by using frontier orbitaltheory.

求取了四氢呋喃和环氧丁烷单体与仲氧鎓离子反应的过渡态，并根据频率分析和内禀反应坐标计算对过渡态的合理性进行了确认。

To understand how the crystal conformer converts to the active conformer, here the internal rotation potential energy surface around the two C—N bonds in the sulfonylurea bridge of monosulfuron has been studied by density functional B3LYP method and 6-31G basis set.

应用密度泛函理论在B3LYP/6-31G水平上对新型除草剂单嘧磺隆绕脲桥部分两个C—N键的内旋转势能面进行计算，然后对势能面上的驻点进行构型优化和过渡态搜索，得到单嘧磺隆4种稳定构象和构象转换过程所涉及的8个过渡态结构。

Density Functional Theory in connection with accurate LCAO basis sets and norm-conserving pseudopotentials were used to study two issues which are (1) The Selective Functionalization of Single-Walled Carbon Nanotubes with Diazonium Radical and (2) The Molecular Dynamic Simulated IR Spectrum of Adsorbed C3H3 and I on the Ag(111) Surface.For the first, we investigated (1) NO2C6H4 direct addition (2) NO2C6H4N2 dissociative addition reaction on semiconductor (8,0), metallic (9,0)and(5,5) carbon nanotubes.

第一部分模拟的结果显示，在半导体性质(8，0)和金属性质(9，0)、(5，5)奈米碳管上，硝基苯自由基(NO2C6H4)的直接加成反应於不同导电性质的奈米碳管间不具有选择性，而硝基苯重氮化合物自由基(NO2C6H4N2)的解离吸附反应会选择性的与金属性质奈米碳管发生反应，因为在金属性质的系统中，奈米碳管於过渡态时会藉由电荷的转移来稳定过渡态的结构，进而帮助反应更快的进行。

During the design process of low voltage equipments using flow chart and state matrix , the distributing control functions using Karnaugh map can satisfy the demand for the design of sequential circuits with/without intermediate states.

用流图法和状态矩阵设计低压电器电路时，卡诺图法分配控制函数能较好满足无过渡态和有过渡态的时序电路设计。本文分别给出了两种电路的设计实

Methanol molecule participates in the proton transfer process, which takes place by a intermolecular six-membered proton-transfer transition state structure instead of the intramolecular four- membered. Consequently, the activation energy of the proton-transfer process is reduced greatly,resulting in the carbon-carbon bond formation process become the rate-determining step. The results are consistent with Aggarwal's the latest dynamics experiments.

CH3OH分子参与质子转移过程，使得原本通过四元环结构过渡态的质子转移过程通过六元环结构过渡态实现，从而极大地降低了质子转移过程的活化能，碳-碳键形成过程进而成为反应的速度控制步骤，研究结果与Aggarwal等的最新动力学研究成果相吻合。

Whereas, at the second stage H-transfer from indole to malonate occurs with the formation of the new C—H bond, the energy barriers calculated for this step are 99.2 and 115.1 kJ/mol for the R - and S -configuration product, respectively.

其中第一阶段由复合物经过渡态TS1生成中间体IM，是C—C键的形成阶段，该阶段的活化能垒较后一阶段要大，是该反应的决速步骤；第二阶段由IM经过渡态TS2生成产物，完成H迁移和C—H键的形成。

For three different reaction paths leading to ortho, meta, para-chloropyridine, two transition states have been located by PM3 on each reaction path, while only one transition state by ab initio, however both methods give the same results: the energy of transition state and activation barrier on producing 2-chloropyridine are the lowest among three reaction paths, so 2-chloropyridine is obtained priorly, which agrees with the experimental results.

生成邻、间、对氯代吡啶三条不同反应途径PM3方法优化得到两个过渡态，而从头算方法中只优化得到一个过渡态。但两种方法的研究结果均表明：三条反应途径中生成2-氯吡啶的过渡态能量和活化能最低，因此反应优先生成2-氯吡啶，与实验结果一致。

Values, the chemical composition of biotite of them and their petrochemical composition on the corresponding dia grams are all distributed transitionally between the "typi cal areas"; 2 that the micro-elements indicating genesis and the REE distribution parttens display the transitional change from the mines in North to those in South in this region; 3 that their K-Ar age of biotite is distinctively inconsistent with their Rb-Sr age of total rocks; and 4 that there occur several rock body groups with various genetic features which are formed at the corresponding time in the same Pb-Zn ore fields.

具体表现在全岩锶同位素初始比值、黑云母化学成分，岩石化学成分在相应图解上不集中而呈&过渡态&分布；微量元素成因特征及稀土分配型式在本区空间上呈&过渡态&展布；岩浆分异演化过程中各种地球化学演化参数不连续变化；全岩Rb-Sr同位素年龄与黑云母K-Ar年龄值严重不合；同一矿区，普遍发育不同岩性组合的岩体群等等。因此，地洼型多因复成成岩成矿作用在湘南铅锌矿床形成过程中是一个带有普遍性的区域成矿规律。

It was very interesting to find that the carbonate species on the O2/Ov/CeO2(110) surface desorbs to CO2 through the bidentate and monodentate intermediates.

过渡态计算发现，O2/Ov/CeO2(110)表面的三齿碳酸盐物种经两齿、单齿过渡态脱附生成CO2。

The reaction was assumed to be an electronphilic attack of nitrosonium on imines, resulting a four-member ring intermediate.

推定该反应经历了一个四员环过渡态，在过渡态中通过化学键的断裂与重组生成了相应的重氮盐和芳香醛。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失