Theoretical study on the lithium bond interaction of furan homologues C_4H_4Y (Y=O, S) with LiCH_3 via DFT and MP2

The optimizations geometries and interaction energy corrected by BSSE of the complexes between C4H4Y (Y=O, S) and CH3Li have been calculated at the B3LYP/6-311 G** and MP2/6-311 G** levels. Three complexes were obtained. Abnormally, the calculations showed that all the C10—Li14 bond lengths increased obviously but the blue-shift of C10—Li14 stretching frequency occurred after formed complexes. The calculated binding energy with basis set super-position error (BSSE) and zero-point vibrational energy corrections of complexes I―III is ?45.757, ?35.700 and ?39.107 kJ·mol?1, respectively. The analyses on the combining interaction with the atom-in-molecules theory (AIM) also showed that a relatively strong lithium bond interaction presented in furan homologues C4H4Y---LiCH3 systems. Natural bond orbital theory (NBO) analysis has been performed, and the results revealed that the com- plex I is formed with n-σ type lithium bond interaction between C4H4O and LiCH3, complex II is formed with π-s type lithium bond interaction between C4H4O and LiCH3, and complex III is formed with π-s and n-s type lithium bond interactions between C4H4S and LiCH3, respectively.     

工作面滞后支承压力分布规律

为获得综采工作面滞后支承压力的分布规律,采用理论分析、数值模拟及现场实测的方法,对兖州矿区工作面滞后支承压力分布规律进行了分析.分层开采与综放开采工作面滞后支承压力变化规律是,随着采高的增大,工作面滞后支承力的距离加大,垂直应力集中系数差别不大.实例结果表明:分层滞后支承压力在工作面后方160～180m以外稳定,综放工作面在其后方200 m以外稳定.     

Atomic-scale segregation behavior of Sn/Ti and O at Σ3[11¯0](111) grain boundary in niobium

First-principle calculation was performed to illustrate the atomic arrangement and segregation behavior of Sn/Ti and O in View the MathML source grain boundary, and the interaction of oxygen interstitials with Sn/Ti atoms on the grain boundary was studied. The analyses on the segregation energies and geometric positions, and the electron densities show that Sn, Ti and O atoms segregate at the Σ3 grain boundary. And the preferred segregation sites of the impurities at View the MathML source were determined. When Sn segregates at grain boundary plane, the O atom prefers to the bulk-like site and shows no segregation tendency at grain boundary, whereas the segregated Ti atom can slightly enhance oxygen segregation at the grain boundary.     

浅谈临界参数在化工计算中的应用

文章通过介绍化合物临界参数的计算方法,以及临界参数在化工计算中的3个重要应用:液体密度计算;气体热容计算;真实气体状态方程参数计算。可得出,临界参数是非常重要的化工物性数据,在化工计算中应引起重视。     

有旋流动的赝势函数及其对超跨声速流动的应用

本文应用缩项法对叶轮机S_1与S_2流面上熵及转焓都不均匀的有旋流动引入一新通用函数——赝势函数,它保持了势函数的优点,但却完全解除了均熵无旋的限制。特别是对于含激波的超跨声速流动的求解,赝势函数提供了一种新的物理上完全相容,数值解简便的有力工具。     

任意旋成面叶栅B类气动杂交命题周角函数型变分有限元解

本文建立了任意旋成面叶栅B型周角函数变分有限元方法,并成功地应用于轴流叶栅和离心叶栅的气动设计计算,从而可使叶型设计建立在更加科学和合理的基础之上。     

小螺桨烷的量子化学计算

在微机 DUAL-68000-83/80上改编并调试通过了半经验分子轨道程序 MNDO 及从头算 MQM81和 ABHF 程序.对〔1.1.1〕螺桨烷、〔2.1.1〕螺桨烷、〔2.2.1〕螺浆烷和〔2.2.2〕螺桨烷进行了 Hellmann-Feynman 力的从头算分子轨道理论研究.     

(P(x),,,-)逻辑的语义问题

本文得出了在 (P(x) , , ,- )逻辑的语义问题中 ,标准命题演算系统的每条公理在 (P(x) , , ,- )逻辑中都是模糊恒真的 ,但标准命题演算系统的定理 ,在 (P(x) , , ,- )逻辑中却不都是模糊恒真的。     

Tix-Nb1-x合金结构及弹性性质的第一性原理研究

本文基于密度泛函理论的第一性原理计算方法详细地计算了高温高压下不同铌含量对Tix-Nb1-x (x=0, 025, 05, 075,1)二元合金的能量和结构的影响。结果表明,零温零压下不同铌含量下的三种稳定的合金组成结构分别为六角密堆结构Nb025Ti075,体心立方结构 Nb05Ti05和体心立方结构Nb075Ti025,所得的稳定的合金结构晶格参数与相关的实验值和理论值符合的很好。这样, 分别计算了在压强60GPa范围内的稳定的合金结构的弹性性质和弹性模量。     

载流子的有效质量研究酞菁钴的传输特性(英文)

酞菁钴由于在无机/有机二极管中表现出的诸多显著的特点而受到关注.为了更好的理解其内部的载流子传输的微观机制,利用密度泛函理论,采用广义梯度近似,关联函数选择Becke exchange plus Lee-Yang-Parr(BLYP)计算了其能带结构.并由其能带结构计算了电子和空穴的有效质量,得到电子的迁移率是空穴的两倍多.从而说明与其他很多的有机材料相比,酞菁钴电子的传输是占主导的有机材料.