浅谈解的存在唯一性定理在《偏微分方程数值解》中的应用

从一个新的角度讨论常微分方程中解的存在唯一性定理在偏微分方程数值解法中的重要应用。给出一类伪双曲型偏微分方程的新的分裂混合有限元数值格式,将该格式转化成常微分方程系统,利用解的存在唯一性定理证明该系统是存在唯一解的。通过简短的讨论、概述明确解的存在唯一定理在偏微分方程数值解中的应用方法．并希望能够在教学科研未来的发展中有新的观念。     

延迟双向联想记忆神经网络的周期振荡现象研究

带轴突信号传输延迟的双向联想记忆(BAM)神经网络是两层异联想网络,本文详细讨论带延迟BAM网络周期解的存在与唯一性,得到了一个充分条件;并用具体例子验证了所得结论的正确性。我们的结果对于具体的延迟BAM振荡神经电路的设计和应用具有重要的指导意义。     

任意形状导体系统电容量计算方法的理论探讨

基于国内外电磁学教课书对电容器电容量的计算大多仅涉及几种特殊结构电容器 ,笔者从梁灿彬等人的《电磁学》的相关内容出发 ,用静电唯一性定理由简入深、由特殊到普通对任意形状导体电容器之电容量的计算方法进行了严格的证明 该工作有助于深化对电容、电容器电容量等概念的正确理解     

Generalized Theory of Thermoelastic Diffusion for Anisotropic Media

The equations of generalized thermoelastic diffusion, based on the theory of Lord and Shulman with one relaxation time, are given in anisotropic media. A variational principle for the governing equations is obtained. Then we show that the variational principle can be used to obtain a uniqueness theorem under suitable conditions. A reciprocity theorem for these equations is given. The obtained results are valid for some special cases that can be deduced from our generalized model.     

Convolutional Variational Principle,Reciprocal and Uniqueness Theorems in Linear Fractional Two-Temperature Thermoelasticity

Two general models of fractional heat conduction law for non-homogeneous anisotropic elastic solid is introduced and the constitutive equations for the two-temperature fractional thermoelasticity theory are obtained, uniqueness and reciprocal theorems are proved and the convolutional variational principle is established and used to prove a uniqueness theorem with no restrictions imposed on the elasticity or thermal conductivity tensors except symmetry conditions. The two-temperature dynamic coupled, Lord-Shulman and fractional coupled thermoelasticity theories result as limit cases. The reciprocity relation in case of quiescent initial state is found to be independent of the order of differintegration.     

On the Theory of Two-Temperature Thermoelasticity with Two Phase-Lags

The present paper is concerned with the theory of two temperature thermoelasticity with two phase-lags in which the theory of heat conduction in deformable bodies depends on two distinct temperatures – the conductive temperature and the thermodynamic temperature. A generalized heat conduction law with dual-phase-lag effects was proposed by Tzou (1995) for the purpose of considering the delayed response in times due to the microstructural interactions in the heat transport mechanism. Recently, Quintanilla (2008) has proposed to combine this constitutive equation with a two temperature heat conduction theory and has proved that a dual-phase-lag theory with two temperatures is a well-posed problem. In the present work we consider the basic equations concerning this dual-phase lag theory of two temperature thermoelasticity and make an attempt to establish some important theorems in this context. A uniqueness theorem has been established for a homogeneous and isotropic body. An alternative characterization of mixed boundary initial value problem is formulated and a variational principle as well as reciprocal principle have been established.     

On Uniqueness and Continuous Dependence in Nonlinear Thermoviscoelasticity

This paper deals with the nonlinear theory of thermoviscoelasticity. A uniqueness result and the continuous dependence of solutions upon initial state and body loads are presented for heat conducting materials of the Kelvin–Voigt type.     

On the Two-Temperature Green–Naghdi Thermoelasticity Theories

The constitutive laws for two-temperature Green–Naghdi theories are given. It is proved that the two-temperature thermoelasticity theory admits dissipation of energy and the theory of elasticity without energy dissipation is valid only when the two-temperatures coincide. The uniqueness and reciprocal theorems are proved for a linear anisotropic and inhomogeneous thermoelastic centro-symmetric solid in the frame of two-temperature Green–Naghdi theories. The convolutional variational principle is established for the two-temperature Green–Naghdi theory of type III. A continuous dependence result is given for an isotropic solid.     

“I want to be different from others in cyberspace” The role of visual similarity in virtual group identity

The present study investigated the impact of the visual similarity shared among virtual group members on group identity and conformity. In achieving this goal, the current study distinguished the similarity coming from being in the same experimental group (i.e., transient group membership) and the similarity coming from the same social group membership (i.e., lasting group membership), in response to the critique that these two group memberships have not been set apart in previous computer-mediated group research. The current study also attended to the fact that previous research on computer-mediated groups restricted personality traits that might have affected group identity formation and conformity in virtual groups. In response to this constraint, the present study included participants’ needs to be different from others (NFU) and needs for inclusion (ISC) to a hypothesized path model that was founded on the SIDE model. Furthermore, the author examined whether the same hypothesized path model could uphold across the differentiated levels of similarity shared among group members.     

FINITE ELEMENT MODELING AND SIMULATION OF WELDING. PART 3: EFFICIENCY AND INTEGRATION

Welding simulation has advanced from the analysis of laboratory setups to real engineering applications during the last three decades. This development is outlined and the directions for future research are summarized in this review, which consists of three parts. This parts focuses on computational strategies and how they are integrated with other methods to facilitate the use of simulations in engineering. These developments have lead to the increased application of welding simulations in industry.