Inverse hydrogen bonds between SiH_4 and hydrides of Na,Mg and Be

The optimized geometries of the three complexes between MeHn (Me=Na,Mg,Be;n=1 or 2) and SiH4 have been calculated at the B3LYP/6-311++g**,MP2/6-311++g(3df,3pd) and MP2/aug-cc-pvtz levels,respectively.The red-shift inverse hydrogen bonds (IHBs) based on Si-H,an electron donor,were reported.The calculated binding energies with basis set super-position error (BSSE) correction of the three complexes are-5.98,-8.65 and-3.96 kJ mol-1 (MP2/6-311++g(3df,3pd)),respectively,which agree with the results obtained via M...     

a-CdSe超快光电探测器特性研究

本文报道淀积条件对非晶态硒化镉(a-CdSe)薄膜微区结构的影响,并对利用a-CdSe为光敏介质的超快光电探测器的特性进行了比较深入的测试研究。     

非晶态硒化镉薄膜瞬态光电特性

本文报道用真空热蒸发法淀积的非晶态硒化镉薄膜作光敏介质制备超快光电导探测器。用对撞脉冲锁模Nd:YAG激光器产生的超短光脉冲序列对探测器的响应时间进行检测,结果表明a-CdSe薄膜对皮秒(10^-12秒)级的超短光脉冲作用具有良好的瞬态响应光电特性,探讨a-CdSe薄膜快速弛豫过程的内在机理。     

Bitwistor and Quasitriangular Structures of Bialgebras

In this article, we first introduce the notion of a bitwistor and discuss conditions under which such bitwistor forms a bialgebra as a generalization of the well-known Radford's biproduct. Then, in order to obtain new quasitriangular bialgebras, we consider a construction called twisted tensor biproduct, which is a special case of bitwistor bialgebra, and give a necessary and sufficient condition for such twisted tensor biproduct to admit quasitriangular structures.     

Double Biproduct Hom-Bialgebra and Related Quasitriangular Structures

Let(H, β) be a Hom-bialgebra such that β~2= id_H.(A, α_A) is a Hom-bialgebra in the left-left Hom-Yetter-Drinfeld category (_H~H)YD and(B, α_B) is a Hom-bialgebra in the right-right Hom-Yetter-Drinfeld category YD_H~H. The authors define the two-sided smash product Hom-algebra(A■H■B, α_A ? β ? α_B) and the two-sided smash coproduct Homcoalgebra(A◇H◇B, α_A ? β ? α_B). Then the necessary and sufficient conditions for(A■H■B, α_A ? β ? α_B) and(A◇H◇B, α_A ? β ? α_B) to be a Hom-bialgebra(called the double biproduct Hom-bialgebra and denoted by(A_◇~■H_◇~■B, α_A ? β ? α_B)) are derived. On the other hand, the necessary and sufficient conditions for the smash coproduct Hom-Hopf algebra(A◇H, α_A ? β) to be quasitriangular are given.     

单电子卤键复合体系H_3C…Br—Y(Y=H,CN,NC,CCH,C_2H_3)的作用机制

对单电子溴键复合物H3C…Br—Y(Y=H,CCH,CN,NC,C2H3)的结构与性质进行了理论研究.在B3LYP/6-311++G**水平上计算了稳定构型并做了频率分析.BSSE矫正的相互作用能(EBSSE)和NBO及AIM分析输入的波函数在MP2/6-311++G**水平下完成.复合物H3C…Br—Y中,CH3(供电子体)自由基均提供一未成对电子与Br—Y中Br(受电子体)形成了单电子溴键,此单电子溴键也具有三电子键的特征.单电子溴键的形成导致甲基H的背向Y弯曲和Br—Y键的拉长及红移单电子溴键复合物的产生.考察了电子受体中不同取代基,C(spn)-Br杂化及溶剂的存在对复合物作用的影响,将单电子氢键,单电子卤键和单电子锂键的作用强度做了对比,进一步对Popelier提出的氢键体系中的前三个重要拓扑指标在单电子溴键体系中的重现性进行了探讨.     

高速电梯气动特性研究与风口设计

高速电梯运行时，井道内气压的快速变化会对轿厢运行的稳定性及安全性产生极大影响．为解决上述问题，提出了三种在井道壁面上开风口的设计方案，运用计算流体力学分析软件FLUENT对电梯运行过程中的空气流动状态进行数值仿真，同时改变风口形状以及数量，对井道内风速变化、轿厢所受气动阻力及气动力矩进行分析．分析结果表明，在提出的三种开风口方案中，上下圆形风口为最优，与未开风口时相比，轿厢气动阻力减小22.05 %，侧翻力矩减小29.87 %，俯仰力矩减小18.02 %．最后进行试验验证，表明了开风口方案的有效性，研究结果可为井道风口的设计提供理论依据．     

Two Results on Brzeziński π-crossed Product

We give the necessary and sufficient conditions for a family of Brzezínski crossed product algebras with suitable comultiplication and counit to be a Hopf π-coalgebra. On the other hand, necessary and sufficient conditions for the Brzeziński π-crossed product A?H to be a coquasitriangular Hopf π-coalgebra are derived, then the category ^A?H ? of the left π-comodules over A?H is braided.