Electrostatic potentials of molecules and prediction of the lewis acid-base properties of solvents,part I. General considerations

Summary Electrostatic potentials in the vicinity of isolated molecules of typical nonaqueous solvents were computed in the MNDO approximation. It was found that the calculated dipole moments are in good agreement with experimental values. However, it turned out that in many cases electrostatic interactions of ions with solvent molecules cannot be described in the frame of ion-dipole interactions. Thus, two computable parameters,UN andUP describing short-range electrostatic interactions of a solvent molecule with a cation or an anion of radiusR were proposed. The dependence ofUN andUP uponR is analyzed in the context of ion-solvent interactions.

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Elektrostatische Potentiale von Molekülen und Voraussage von Lewis-Säure-Base-Eigenschaften von Lösungsmitteln, 1. Mitt.: Allgemeine Grundlagen

Zusammenfassung Es wurden die elektrostatischen Potentiale in der Umgebung von isolierten Molekülen typischer nichtwäßriger Lösungsmittel in der MNDO-Näherung berechnet. Die berechneten Dipolmomente waren in guter Übereinstimmung mit den experimentellen Werten. Es wurde jedoch beobachtet, daß in vielen Fällen die elektrostatischen Wechselwirkungen von Ionen mit Lösungsmittelmolekülen nicht im Rahmen von Ionen-Dipol-Wechselwirkungen beschrieben werden können. Dafür wurden zwei berechenbare ParameterUN undUP zur Beschreibung von elektrostatischen Wechselwirkungen im Nahbereich eines Lösungsmittelmoleküls mit einem Kationen- oder AnionenradiusR vorgeschlagen. Die Abhängigkeit vonUN undUP vonR wurde im Zusammenhang von Ionen-Solvens-Wechselwirkungen untersucht.

     

中能区光学势的温度效应

本文在Skyr}e相互作用、核物质近似和自洽半经典方法的基础上，将微观光学势的自洽研究推J“到中能区(60-r300MeV)，研究了”+907r在该能区光学势的径向形状和温度效应     

矿渣粉加固粉土的理论分析及路用性能研究

提出了矿渣粉加固粉土的相关理论。将矿渣粉在加固土中的作用归结为火山灰胶凝效应和微集料填充效应,而火山灰胶凝效应又可进一步归结为水化作用、激发作用和离子交换作用;认为微集料填充效应与矿渣粉细度极为相关;用框图归纳了矿渣粉加固土的两种作用效应。进行了矿渣粉、石灰粉加固土无侧限饱水抗压强度、水稳定性、冻稳定性、温度收缩和干燥收缩等路用性能试验,并进行比较。结果表明,矿渣粉加固土所测路用性能指标优于石灰粉加固土。为工程应用提供了试验依据。     

A viscoelastic constitutive model of rubber under small oscillatory load superimposed on large static deformation considering the Payne effect

The viscoelastic behavior of carbon-black-filled rubber under small oscillatory loads superimposed on large static deformation is dealt with. In this class of problems, as the strain amplitudes of the load increase, the dynamic stiffness decreases, and this phenomenon is known as the Payne effect. Besides the effects of the static deformation and the frequencies of the superimposed dynamic load, the Payne effect is considered in this study. Influence factors are introduced in this model in order to consider the influence of static predeformation, the dynamic-strain-dependent properties, and frequency-dependent properties. For simplicity, separation of the three dominant variables, frequency, prestatic deformation, and dynamic amplitude of strain, is assumed. The Kraus model is used for describing the Payne effect. Dynamic tension tests are executed to obtain the model parameters and also for the verification of the proposed model. The suggested constitutive equation shows reasonable agreement with test data.     

全同超形变带转动惯量的粒子数守恒计算

利用推转壳模型的粒子数守恒方法计算了超形变(SD)转动带¹⁹²Hg和¹⁹⁴Hg(1,2,3)的带首转动惯量.分析了带首附近的组态结构及带首转动惯量随对力强度的变化.带首转动惯量之差δJ₀对对力强度十分敏感,而对Nilsson能级参数K、μ及形变参数并不敏感.对力及堵塞效应是造成带首转动惯量差别的主要因素.但与正常形变核相比,对力强度似有较大程度减弱.     

Transition between layered and filamentary types of anisotropy in layered superconducting structures

A model of layered superconducting structure consisting of alternating anisotropic superconducting layers S₁ and S₂ with different transition temperatures is considered. It is shown that due to competition between two origins of anisotropy - effective-mass anisotropy of individual layers and proximity-induced anisotropy the effective anisotropy of the whole system signficiantly varies temperature. The components of the effective-mass tensor m_c (along the anisotropy axis) and m_a (perpendicular to the anisotropy axis) strongly depend upon temperature. This may lead to transition between layered (m_c > m_a) and quasi one-dimensional (m_c < m_a) types of anisotropy as well as to biaxial-type anisotropy which is also temperature dependent. The field distribution in a tilted vortex in a biaxial superconductor is calculated. The change in the properties of the vortex lattice with temperature in such systems is also investigated. The properties of YBa₂Cu₃O_x/PrBa₂Cu₃O_y multilayers are discussed in this connection.     

工业CT重建图像中边缘梯度效应引起的高频伪影

为研究伪影对大型工件内部密度锐变区域高对比度微小缺陷检测的影响,从一个简单的轴对称断层模型出发,计算了边缘梯度效应引起的通过物体内部不同材料交界面处的射束的投影偏差。并研究采样相位的影响,探讨了由此偏差引起的重建图像中的高频伪影的表现形式。计算结果表明,高频伪影具有相当的强度,且具有与缺陷相似的表现形式,从而影响工业CT的检测能力。结合点扩散过程,高频伪影强度的计算为评估工业CT边缘处的缺陷检测能力提供了理论依据。     

提高电脑建筑效果图制作效率的措施

对提高电脑效果图制作效率的重要性及常用方法进行了探讨，分析了制图效率低的原因，对合理配置计算机系统、优化计算机系统资源、熟练掌握软件使用技巧等进行了具体论述。     

InAs/GaSb/AlSb resonant tunneling spin device concepts

We discuss device concepts for creating spin-polarized current sources without external magnetic fields, using non-magnetic 6.1 Å semiconductor resonant tunneling structures. Spin filters, spin pumps, and spin transistors that exploit structural and bulk inversion asymmetries will be examined.     

承受拉-扭组合载荷的薄壁圆筒屈服时产生塑性流动的条件

提出了在无外力作功的情况下，具有Bauschinger效应的弹塑性材料处于屈服状态产生自发的塑性流动时应满足的条件．这个条件不仅与材料的力学性能有关，而且还处决于材料的具体的载荷边界条件和变形．举例说明了承受拉一扭组合的薄壁圆筒中，采用组合强化模型时，产生塑性流动的具体条件．