幂硬化材料平面应变条件下的复应力函数解

本文导出应力函数的几个特解，以便增加对幂硬化材料平面应变问题的认识     

The First Total Synthesis of Triprenylquinone and Hydroquinones

Marine natural products have received much attention for their attractive structural features and biological activities1. Since the isolation of the moritoside, about 10 related triprenylquinones and hydroquinones were isolated. Some of these natural products exhibit interesting biological effects including inhibit cell division of fertilized starfish eggs2 and anti-HIV3. Triprenylquinone and hydroquinones 1, 2 and 3 were recently isolated from endemic nudibranch Leminda millecra collected i…     

C80n (D2,Ih)的Jahn-Teller畸变和电子光谱

用INDO系列方法研究C80n(D2,Ih)的Jahn-Teller畸变,表明C80(D2)比C80(Ih)稳定,与实验一致;C80n(D2)未发生Jahn-Teller畸变,C80n(Ih)的部分离子发生明显的Jahn-Teller畸变,电荷对C80(Ih)稳定性有显著影响.首次计算其电子光谱,不仅得到C80(D2)与实验一致的吸收峰,还预测了C80n(D2,Ih)的电子光谱,对电子跃迁进行理论指认.C80n(D2)光谱与C80(D2)相比发生吸收峰红移,而C80n(Ih)光谱与C80(Ih)相比发生吸收峰兰移,其原因是C80n(D2)的LUMO-HOMO能隙比C80(D2)小,而C80n(Ih)的能隙则比C80(Ih)的能隙大.     

C_(70)O的结构和UV-Vis光谱的理论研究

用INDO系列方法对C_70O的8种异构体构型进行系统研究,表明C_70O中O主要加在C_1一C_2和C_3—C_3键上,形成具有C_S对称性且不开环的环氧化合物结构.以优化构型为基础,进行UV-Vis光谱计算,表明C_70O主峰与C_70基本一致,并在460um以上产生特征吸收峰,计算结果与实验值一致.在对其特征吸收峰进行理论指认的同时,讨论了吸收峰红移的原因,并指出C_70O可能由4种异构体组成.     

POSITRON ANNIHILATION WITH VACANCIES IN THIN SURFACE LAYER OF As HEAVILY DOPED Si

The lifetime spectroscopy of slow positron accelerated with linear accelerator and pulse punch system was first used to analyze the vacancies in the thin surface layer of silicon heavily doped with arsenic. The results demonstrated that no mono-vacancy was detected to support the arsenic-vacancy complex models for explaining the electrical deactivation mechanism of arsenic-heavily-doped silicon.     

心脏内部血流实时动态径迹的非侵入性显示方法——超声微泡血流图

前言人体心内血液流动是生命存在的象征.显示人体心内血液流场对研究心脏力学及其病理改变有着重要意义.虽然流体力学中显示流场动态的方法有多种形式,但要显示人体心内血液流场,又要做到...     

C28H4-nCln(n=1~3)与CH4-nCln(n=1~3)的结构和电子光谱的理论研究

用INDO系列方法对C_(28)H_3Cl,C_(28)H_2Cl_2,C_(28)HCl_3,CH_3Cl,CH_2Cl_2,CHCl_3进行了几何构型优化,Q_(28)H_3Cl,Q_(28)HCl_3,CH_3Cl,CH_3Cl为C_3_v对称性,C_(28)H_2Cl_2,CH_2Cl_2为C_2.对称性,这六个分子的基态都是稳定闭壳层分子,以此构型为基础计算了上述分子的电子光谱,Q_(28)H4-nCl_n(n=1～3)的电子光谱属于理论预测性质.     

C60P4 的电子结构和光谱研究

用INDO 方法研究C60与P4 四面体的超分子聚合作用, 表明所形成的四种异构体中, P4 四面体的一条棱与C60母体的某一双键相连时形成的开环结构最稳定, 此产物具有C2v对称性.以优化构型为基础, 计算四种产物异构体的UV 谱, 在对电子跃迁进行理论指认的同时, 讨论了产物UV 谱带红移的原因.     

MULTIPLE SOLUTIONS TO SINGULAR BVPS WITH VARIABLE COEFFICIENT ON THE HALF-LINE

This paper is concerned with a singular second-order nonlinear boundary value problem with a time depending on derivative operator and posed on the positive half-line. The nonlinearity is derivative-dependent, which has singularities at t=0 and/or x=0, and may change sign. The method of the upper and lower solutions on unbounded domains combined with the topological degree theory are employed to prove the existence and multiplicity of solutions.