有限温度格点U(1)及定模U(1)–Higgs模型Symanzik作用量的解析研究

用变分累积展开方法(VCE)解析研究了Symanzik作用量形式的有限温度格点U(1)及定模U(1)-Higgs规范模型,并计算了序参量Polyakov线及临界指数β.结果表明,采用Symanzik作用量的变分累积展开比Wilson作用量收敛快.     

非饱和土固结的混合物理论（Ⅰ）

非饱和土是由土粒、水、气组成的三相介质，本以混合物理论为基础研究了非饱和土的固结问题。中导出了各向异性多孔介质及非饱和土 的有效应力的理论公式，把有效应力原理和Curie对称原理作为非饱和土的两个重要的本构原理，建立了非饱和 土固结的数学模型：由25个方程求解25个未知量。在增量线性化的情况下，本模型简化为5个控制方程求解5个未知量：3个固相位移、孔隙水压力和孔隙气压力。模型中包含7个材料参数，都可由试验测定，便于工程应用，Biot理论是本模型的特例。     

背散射和饱和效应对双向环形激光场的影响

理论上分析了双向环形气体激光中背散射和饱和效应对光场统计性质的影响，求出了强度相关函数的有效本征值。与实验测量值比较表明，具有背散射的全饱和激光模型与实验吻合得更好，而其它激光模型偏差较大     

Multicriteria optimization of a composite cylindrical shell subjected to thermal and dynamic actions

Multicriteria optimization of the structure and geometry of a laminated anisotropic composite shell subjected to thermal and dynamic actions is considered. From the known properties of monolayers and the given values of variable structural and geometric parameters, the thermoelastic properties of the layered anisotropic composite are determined. The criteria to be optimized—the natural frequency and the thermal stresses—depend on two variable design parameters, stochastic properties of the composite, and temperature. In the space of the optimization criteria, the domain of allowable solutions and the Pareto-optimal region are found.Translated from Mekhanika Kompozitnykh Materialov, Vol. 40, No. 6, pp. 753–760, November–December, 2004.     

A quantum generalization of equilibrium statistical thermodynamics: Effective macroparameters

We propose a generalization of statistical thermodynamics in which quantum effects are taken into account on the macrolevel without explicitly using the operator formalism while traditional relations between the macroparameters are preserved. In a generalized thermostat model, thermal equilibrium is characterized by an effective temperature bounded from below. We introduce fundamental theoretical macroparameters: the effective entropy and the effective action. Because the effective entropy is nonzero at low temperatures, we can write the third law of thermodynamics in the form postulated by Nernst. The effective action at any temperature coincides with the product of standard deviations of the coordinate and momentum in the Heisenberg uncertainty relation and is therefore bounded from below. We establish that the ratio of the effective action to the effective entropy in the low-temperature limit is determined by a holistic stochastic-action constant depending on the Planck and Boltzmann constants. We show that the same results can be obtained in the framework of a modified version of thermofield dynamics in which the quantum oscillator is described by a temperature-dependent complex macroscopic wave function. We study the discrepancy between the behavior of the action-to-entropy ratio in the low-temperature limit in our proposed theory and that in quantum equilibrium statistical mechanics, which can be verified experimentally. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 154, No. 1, pp. 183–196, January, 2008.     

Angular and temperature‐related specific features of averaging of hole effective masses in p‐Ge at low temperatures

Microwave magnetoresistance of lightly doped (nondegenerate) p‐Ge has been studied by the electron spin resonance method, which can record the derivative of the microwave absorption with respect to the magnetic field. The change in the absorption is proportional to that in the conductivity of the semiconductor in the magnetic field (magnetoresistance). It was found that the averaging time of the light and heavy holes effective masses depends on temperature and on the magnetic field direction in a sample. An analysis of the derivative made it possible to determine regions of the fastest effective mass averaging.     

INTERACTION MODELS FOR EFFECTIVE THERMAL AND ELECTRIC CONDUCTIVITIES OF CARBON NANOTUBE COMPOSITES

The present article provides supplementary information of previous works of analytic models for predicting conductivity enhancements of carbon nanotube composites. The models, though fairly simple, are able to take account of the effects of conductivity anisotropy, nonstraightness, and aspect ratio of the CNT additives on the conductivity enhancement of the composite and to give predictions agreeing well with existing experimental data. The omitted detailed derivation of this model is demonstrated in the present article with a more systematical analysis, which may help with further development in this direction. Furthermore, the effects of various orientation distributions of CNTs are reported here for the first time. The information may be useful in design or fabrication technology of CNT composites for better or specified conductivities.     

Cyclic shear of saturated soil: the evolution of stress inhomogeneity

Received July 30, 2001 / Published online February 28, 2002     

7Be在Pd和Au中衰变率变化的相对测量

将HI-13串列加速器次级束流线产生的放射性核素7Be分别注入到Pd和Au中,利用两个高纯锗探测器同时测量7Be EC衰变核素7Li第一激发态放出的478 keV γ射线产额随时间的变化,发现7Be在Pd中的衰变率比在Au中大(0.8±0.2)%,并讨论了衰变率差别与这两种材料的电子亲合势及有效电子密度的关系.     

Fifty years of Szigeti’s dielectric theory — A review

During the period 1949–1961 Szigeti published four seminal papers on the dielectric behaviour of crystals. Szigeti’s theory is applicable to isotropic and anisotropic, ionic and covalent crystals with different structures. Szigeti’s theory connects dielectric, spectroscopic and elastic properties. An important outcome of Szigeti’s theory is the concept of the effective ionic charge (s). It is pointed out that s correlates with a number of physical properties and is a measure of ionicity of the interatomic bond. Since Szigeti’s work, several theoretical models have been proposed to account for the fact that s < 1. These models provide an insight into the complex polarization mechanisms in solids. This review summarizes Szigeti’s work and the work that followed; the implications and applications of Szigeti’s theory are discussed. Some new results are also included. Dedicated to the memory of late Prof. P S Narayanan.