Binding energies and interaction origins between nonclassical single-electron hydrogen,sodium and lithium bonds and neutral boron-containing radicals: a theoretical investigation

Nonclassical single electron hydrogen,sodium and lithium bonds(SEHBs,SENaBs and SELiBs)between single electron acceptors X–A(A=H,Na,Li;X=CN,HCC,HO,NC,CF3)and neutral radicals BY2(Y=H,OH,CH3)and have been systematically investigated by high level theoretical methods,such as second-order Mφller-Plesset perturbation theory(MP2),spin-component-scaled MφllerPlesset theory(SCS-MP2),the coupled cluster method with perturbative triples(CCSD(T)),and the correlation consistent composite approach(ccCA).Binding energies have been corrected for zero-point vibrational effects and(when applicable)basis set superposition error.The quantum theory of atoms in molecules(AIM)and natural bond orbital(NBO)analyses were also employed to qualitatively characterize the single electron bond interactions.The stabilization energy was partitioned via the localized molecular orbital energy decomposition analysis(LMOEDA)method,and both electrostatic and exchange interactions were seen to be major driving forces for the complex stabilization.Interestingly,the sum of the energy contributors of exchange(EEX),repulsion(EREP),polarization(EPOL),dispersion(EDIS)is close to zero and the changes in the interaction energy follow the trend of the electrostatic energy(EES).We observe several linear relationships among the optimized intermolecular parameters and the interaction energies of the various complexes.     

The source of chemical bonding

Developments in the application of quantum mechanics to the understanding of the chemical bond are traced with a view to examining the evolving conception of the covalent bond. Beginning with the first quantum mechanical resolution of the apparent paradox in Lewis’s conception of a shared electron pair bond by Heitler and London, the ensuing account takes up the challenge molecular orbital theory seemed to pose to the classical conception of the bond. We will see that the threat of delocalisation can be overstated, although it is questionable whether this should be seen as reinstating the issue of the existence of the chemical bond. More salient are some recent developments in a longstanding discussion of how to understand the causal aspects of the bonding interaction—the nature of the force involved in the covalent link—which are taken up in the latter part of the paper.     

论公司债券的溢价与折价

发行债券会出现溢价或折价，溢价或折价取决于市场利率与票面利率的不等．溢价或折价的大小可根据公式：△＝Ｃ（ｒ－Ｒ）（１＋Ｒ）ｎ－１Ｒ（１＋Ｒ）ｎ溢价Ｃ（Ｒ－ｒ）（１＋Ｒ）ｎ－１Ｒ（１＋Ｒ）ｎ折价得出，且溢价不是给企业带来的收益，折价也不是给企业带来的损失     

TiN 膜吸附机理及工艺的研究

探讨了ＴｉＮ膜的吸附机理、吸附条件以及空余键力在真空镀膜中的应用。介绍了ＴｉＮ膜的特性，制备及应用前景，包括在加硬膜、耐蚀膜、装饰膜、阻挡膜及光学膜等方面的应用。     

电场作用下金属串配合物[Ru_3(dpa)_4]L_2(L=Cl,C≡N,C≡CPh)结构的理论研究

用密度泛函理论BP86结合自然键轨道分析方法,研究了具有分子导线潜在应用的含二吡啶胺配体(dpa)的金属串配合物[Ru3(dpa)4]L2(1:L=Cl,2:C≡N,3:C≡CPh)的Ru—Ru,Ru—L键及其在电场作用下的结构变化规律,结果表明:(1)配合物基态均存在Ru6+3离域三重键,1中具有1个σ43和2个!43离域键,2中具有σ23,!53和δ53离域键,3中具有1个σ23和2个!53离域键.1的轴向配体形成Ru—Cl弱配位σ键,2和3中Ru与C≡N和C≡CPh(下文简写为CN和CCPh)除形成Ru—C配位σ键外,还具有Ru(dyz,dxz)→L(!*C-N或!*C-C)反馈!键,减弱了Ru—Ru离域!键.且2的CN中N的电负性较大,其反馈!键更强使Ru—Ru键最弱,故Ru—Ru距离为231.(2)电场作用下,低电势端的Ru—Ru和Ru—L键缩短,而高电势端的Ru—Ru和Ru—L键增长;轴向配体的负电荷向高电势端转移,而Ru的正电荷则向低电势端移动;高电势端Ru的自旋密度减小,而低电势端Ru和L的自旋密度增大.因3中CCPh共轭性强,故电荷密度和自旋密度对电场更敏感,有利于电子在分子轴的传输.1~3的前线分子轨道分布、能级和能隙在电场作用下均较稳定.在电场中前线轨道仍能保持金属轴的离域,有利于电子传输.(3)含更大的共轭轴向配体CCPh的3的HOMO-LUMO能隙小于具有相同自旋态的2,故3的导电性可能最好.     

基于特殊阵列递归构造Bent互补函数偶族

单值并元相关函数互补码偶是一类并元自相关函数为脉冲函数的一族码偶。这样的码偶具有能将码偶中的一方码与另一方码的并元移位区分开来的特性。为了进一步研究单值并元相关函数互补码偶,并为其研究提供有效的数学工具,提出了一类新的类Bent函数———Bent互补函数偶族。进一步研究了Bent互补函数偶族的构造方法,给出了应用列正交阵列和列并元最佳阵列偶由低维Bent互补函数偶族递归构造高维Bent互补函数偶族的方法。应用Bent互补函数偶族与单值并元相关函数互补码偶的等价关系,相应地可以构造出许多单值并元相关函数互补码偶。     

分数布朗运动下信用风险结构模型

假设企业资产价值的波动以真实概率服从分效布朗运动,在此基础上推算出时度量信用风险的:公司的违约概率公式,风险债券的价格公式,股票的价格公式以及风险溢价公式等,并且得到在这样的假设条件下画出的信用风险溢价随着资产价值波动项变化而呈现的不同走势接近实证结论.     

广义相关免疫与相关度

讨论了广义相关免疫函数的理论意义和应用价值，发展了相关度的概念，给出了Ｂｅｎｔ函数的相关度及广义相关免疫阶，证明了Ｂｅｎｔ函数是一类理想的广义相关免疫函数．     

基于Cameron-Martin-Girsanov理论的长寿债券定价模型

针对现有长寿债券定价研究中存在的不足,利用Cameron-Martin-Girsanov理论构建长寿债券定价模型,避免了Wang变换方法的主要缺欠,进一步减小了市场不完全性对定价准确性的影响.同时,为满足不同风险偏好投资者的需求,利用分层技术对长寿债券进行分层定价,克服了现有定价模型风险承担模式单一的问题.所构建的长寿债券定价模型较已有模型更加符合金融市场的客观实际和投资者的多样化需求,在一定程度上有助于推进我国长寿风险管理效率的提高.     

元素簇合物LikAlj（k,j≤3）的定域分子轨道研究

在ａｂ ｉｎｉｔｉｏ ３－２１Ｇ基下，用能量梯度法对ＬｉｋＡＬｊ（ｋ，ｊ３）的几何结构进行了优化，并在该构型和６－２１Ｇ基下的采用Ｂｏｙｓ方法进行了定域化计算，结果表明，在ＬｉｋＡｌｊ簇合物中存在着双中心键、多中心键和孤坚电子，同时还用成键性质对稳定性进行了讨论，认为用定域化能够对稳定尾进行较好的解释。