The homogenization of a class of degenerate quasilinear parabolic equations

1. Introduction and main results 1.1 Introduction Let 0T> and nW be an open bounded domain with with Lipschitz boundary, consider the following initial-boundary value problem : () 0div (,,)(,) in (0,)(,)0 on (0,) (0,)|()tTtuuftTPutTuuxeeeeeWWeeW-==?洞=xaxxxin the space [0,;]pXLTV=, where 1,0(,)pVWemW= is a weighted Sobolev space, p is a constant larger than 1, and e is a positive constant, t and x are variables of the functions a and u. The degenerati…     

一矩阵方程组的反射解

We derive necessary and sufficient conditions for the existence and an expression of the （anti）reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D. The explicit solutions of the approximation problem min x∈Ф ｜｜X - E｜｜F was given, where E is a given complex matrix and Ф is the set of all reflexive （or antireflexive） solutions of the system mentioned above, and ｜｜·｜｜ is the Frobenius norm. Furthermore, it was pointed that some results in a recent paper are special cases of this paper.     

单个守恒律方程初边值问题的Godunov算法

This paper is concerned with Godunov’s scheme for the initial-boundary value problem of scalar conservation laws. A kind of Godunov’s scheme, which satisfies the boundary entropy condition, was given. By use of the scheme, numerical simulation for the weak entropy solution to the initial-boundary value problem of scalar conservation laws is conducted.     

关于无粘可压绝热流体的欧拉方程不适定初边值问题的形式解

It is proved that the ill-posed initial value problem of the Euler equations for compressible adiabatic inviscid fluid flow can be only formally solved. The necessary and sufficient conditions for existence of formal solution of some representative ill-posedness initial-boundary value problem are presented. Finally, an example is also given.     

Analytical solution for fixed-end beam subjected to uniform load

A bi-harmonic stress function is constructed in this work. Ariy stress function methodology is used to obtain a set of analytical solutions for both ends fixed beams subjected to uniform load. The treatment for fixed-end boundary conditions is the same as that presented by Timoshenko and Goodier （1970）. The solutions for propped cantilever beams and cantilever beams are also presented. All of the analytical plane-stress solutions can be obtained for a uniformly loaded isotropic beam with rectangular cross section under different types of classical boundary conditions.     

基于遗传机制的蚁群算法求解连续优化问题

A new algorithm is presented by using the ant colony algorithm based on genetic method (ACG) to solve the continuous optimization problem.Each component has a seed set.The seed in the set has the value of component,trail information and fitness.The ant chooses a seed from the seed set with the possibility determined by trail information and fitness of the seed.The genetic method is used to form new solutions from the solutions got by the ants.Best solutions are selected to update the seeds in the sets and trail information of the seeds.In updating the trail information,a diffusion function is used to achieve the diffuseness of trail information.The new algorithm is tested with 8 different benchmark functions.     

Multi-objective optimization of water supply network rehabilitation with non-dominated sorting Genetic Algorithm-II

Through the transformation of hydraulic constraints into the objective functions associated with a water supply network rehabilitation problem, a non-dominated sorting Genetic Algorithm-II （NSGA-II） can be used to solve the altered multi-objective optimization model. The introduction of NSGA-II into water supply network optimal rehabilitation problem solves the conflict between one fitness value of standard genetic algorithm （SGA） and multi-objectives of rehabilitation problem. And the uncertainties brought by using weight coefficients or punish functions in conventional methods are controlled. And also by in- troduction of artificial inducement mutation （AIM） operation, the convergence speed of population is accelerated; this operation not only improves the convergence speed, but also improves the rationality and feasibility of solutions.     

An immune-tabu hybrid algorithm for thermal unit commitment of electric power systems

This paper presents a new method based on an immune-tabu hybrid algorithm to solve the thermal unit commitment （TUC） problem in power plant optimization. The mathematical model of the TUC problem is established by analyzing the generating units in modem power plants. A novel immune-tabu hybrid algorithm is proposed to solve this complex problem. In the algorithm, the objective function of the TUC problem is considered as an antigen and the solutions are considered as antibodies, which are determined by the affinity computation. The code length of an antibody is shortened by encoding the continuous operating time, and the optimum searching speed is improved. Each feasible individual in the immune algorithm （IA） is used as the initial solution of the tabu search （TS） algorithm after certain generations of IA iteration. As examples, the proposed method has been applied to several thermal unit systems for a period of 24 h. The computation results demonstrate the good global optimum searching performance of the proposed immune-tabu hybrid algorithm. The presented algorithm can also be used to solve other optimization problems in fields such as the chemical industry and the power industry.     

Non-formation of vacuum states for Navier-Stokes equations with density-dependent viscosity

We consider the Cauchy problem, free boundary problem and piston problem for one-dimensional compressible Navier-Stokes equations with density-dependent viscosity. Using the reduction to absurdity method, we prove that the weak solutions to these systems do not exhibit vacuum states, provided that no vacuum states are present initially. The essential re- quirements on the solutions are that the mass and energy of the fluid are locally integrable at each time, and the Lloc1-norm of the velocity gradient is locally integrable in time.     

Multi-physics coupling field finite element analysis on giant magnetostrictive materials smart component

This study presents a new method to solve the difficult problem of precise machining a non-cylinder pinhole of a piston using embedded giant magnetostrictive material （GMM） in the component. We propose the finite element model of GMM smart component in electric, magnetic, and mechanical fields by step computation to optimize the design of GMM smart component. The proposed model is implemented by using COMSOL multi-physics V3.2a. The effects of the smart component on the deformation and the system resonance frequencies are studied. The results calculated by the model are in excellent agreement （relative errors are below 10%） with the experimental values.     

具有非凸条件的单个守恒律初边值问题的粘性逼近解的L^1模误差估计

研究具有非凸条件的单个守恒律初边值问题的粘性逼近解的L^1模误差估计．在流函数有一个拐点的条件下,就初始值为两段常数和边界值为常数的情形,根据弱熵解的几何结构,使用匹配行波解方法导出其粘性逼近解和无粘性解间的L^1模误差界为0（ε^1/2＋ε ｜lnε｜）．     

非线性双重退缩抛物方程解有耗竭

研究非线性双重退缩抛物方程第一初边值问题的耗竭性，应用能量方法，对具零Dirichlet边界条件和非负初值的方程，给出了解在有限时间内耗竭的充分条件，从而推广了Tsutsumi M等人的结果。     

粘性p-双调和抛物型方程弱解的唯一性

考虑一类粘性p-双调和抛物型方程的初边值问题.利用Steklov均值,证明了弱解的唯一性.     

一个具有非线性关系的退化四阶抛物方程弱解的存在性

讨论一个具有非线性关系的退化四阶抛物方程的初边值问题,在一些初值的假定下,用时间离散化方法证明了弱解的存在性.     

分离变量法解三维的分数阶混合扩散-波动方程的初边值问题

本文考虑在有限区间上三维的时间分数阶混合扩散-波动方程的初边值问题。使用分离变量法,导出三维的时间分数阶混合扩散方程和初边值问题的基本解。     

一个广义薄膜方程弱解的正则性

考虑一个广义薄膜方程的初边值问题.利用磨光算子及中值定理,在一维空间中,证明了弱解的正则性.     

一类具有非负特征的双曲型方程组的边值问题

研究一类具有非负特征四次型的平面双曲型偏微分方程组,考虑该方程组的与低阶项系数有关的边值问题,获得了关于弱解和古典解的存在唯一件方面的结果.     

关于非线性Klein-Gordon方程解的爆破

用特征函数法系统地讨论了非线性Klein—Gordon方程初边值问题在三类边界条件下解的爆破.     

有限区间上单个守恒律整体弱熵解研究

使用折线逼近法,构造了有限区间上非凸单个守恒律初边值问题的整体近似解,并证明其收敛到初边值问题的整体弱熵解.