过渡态

Chapter 4: selectes the AHPBA as the candidates for inhibitor design for Human Immunodeficiency Virus protease. The cleavable peptides are modified according to the "distorted key" theory, and the new inhibitors are formed.

第四章：以HIV蛋白酶过渡态类似物的抑制剂为研究对象，根据&变形钥匙&理论，把可剪切肽转变成理想的竞争性抑制剂。

The Density Function Theorymethod are employed to study the geometries of the cyanic acid and isocyanic acid on the base of B3LYP/6-31++Gin the paper.

主要采用密度泛函理论方法，在B3LYP/6-31++G水平上，优化了氰酸、异氰酸的结构，分别得到氰酸的能量为-168.69356 a.u，异氰酸的能量为-168.73227 a.u，并对过渡态进行了反应的内禀反应曲线IRC计算。

The reaction barrier will be lowered by the substituents that delocalize the unpair electron in p z orbital of the central carbon atom.

R1和R2位置上取代基对α-氢转移反应势垒的影响取决于取代基对过渡态中碳原子的未参与sp2杂化的p z 轨道上单电子的离域作用。

The third part of this thesis is reactive simulating calculation In this section, some well-known auxiliaries are selected to compute in density functional theory B3LYP on Gaussian 03, from which the relationship between reaction active energies of transition states and enantiomeric excess of chiral products homoallylic alcohols isobtained based on relative reactive ratio theory. Using this relationship, calculations on the reaction of more than eight auxiliaries with four other aldehydes are carried out in AMI and MNDO, proving that N,N\'-dibenzyl tartamide has higher enantioselectivity than others in this reaction.

第三部分为计算化学部分，运用密度泛函理论B3LYP方法在Gaussian03软件上对已经报道的几种手性配体参与的醛不对称烯丙基化反应过程进行模拟计算，基于相对反应速率理论找出两种构型过渡态间活化能的差异与产物光学收率之间的关系；并以此为基础，用AM1和MNDO方法对上述合成的几种配体控制的反应过程进行量化计算，从而在理论上证实了N-苄基酒石酸二酰胺配体在醛的不对称烯丙基化反应中具有较高的立体选择性。

Phosphorus generation fully originates from reduction reaction of hypophosphorous during EN process.

利用量子化学软件高斯03(G03)分子轨道理论中的从头计算法，计算了次亚磷酸在还原过程中可能的中间产物和过渡态的振动频率和总能量。

In Chapter 2, introduces elementary theory and quantum chemistry computation methods, which mainly contained the reaction surface, crossing rules of the potential energy surfaces, tradition transition state theory, spin-orbit coupling mechanism and rules for intersystem crossing.

第二章简要地介绍了量子化学计算方法，主要包括量子化学基本理论和反应势能面、势能面相交与不相交规则、过渡态理论和系间窜越的选择规则。

In Chapter 2, simply introduced elementary theory, mainly contained the reaction surface, crossing rules of the potential energy surfaces, tradition transition state theory, spin-orbit coupling mechanismand rules for intersystem crossing.

第二章简要介绍了基本理论，主要包括反应势能面、势能面相与不相交规则、过渡态理论、自旋-轨道偶合机制和系间窜越的选择规则。

Study on synthesis and thermo-stability of ladderlike polymethyl/phenylsilsesquioxane

利用气相色谱技术对氟代仲丁烷的热稳定性进行了考察，并通过对氟代仲丁烷的热消除产物的定性定量分析，讨论了其热分解机理，以四圆环状过渡态历程和碳正离子重排历程对热消除反应的产物形成进行解释。

In this paper, high-level quantum chemistry calculation methods are used to theoretically investigate basic configuration, conformers, torsion potential energy surface and internal rotation transition state of oxalic acid and oxalyl halides.

第三章采用量子化学的MP2、B3LYP、HF计算方法在6-311++G~水平上，对草酸可能存在的十三种构型进行完全放开的全几何优化及振动频率分析，得到八种稳定构型和五种内转动过渡态构型。

At the same time, the calculated four renormalized PDDCSs indicate that products are strongly polarized at three scattering angles, which can ascribe to three transition states on both PESs.

同时，计算的四个重整化极化依赖微分截面显示产物在三个散射角被强烈极化，这与在两个势能面上的三个过渡态有关。

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