具非齐次线性部分的高阶非线性抛物型方程组的初值问题

本文讨论线性部分为非齐次的高阶非线性抛物型偏微分方程组整体经典解的存在性，得到了这类问题对小初值而言存在整体经典解的一些充分条件．     

具有扩散的广义Brusselator系统的Hopf分歧

在齐次Neumann边界条件下,考虑广义Brusselator系统．首先讨论常微分系统Hopf分歧的存在性,得到渐近稳定的周期解．其次讨论具有扩散的偏微分系统,在扩散系数满足一定的条件下,得到超临界的Hopf分歧,并利用规范形理论和中心流形定理给出空间齐次周期解的渐近稳定性．最后,借助Matlab软件进行数值模拟,证明了定理的结论．同时,正平衡态解和空间非齐次周期解的描绘补充了理论分析结果．     

全空间上一类非齐次椭圆方程正解的衰减

本文研究了非齐次椭圆方程不同衰减正解的存在性和衰减问题.利用上下解方法,得到了两个有着不同衰减的正解的存在性,推广了文献[2]中非齐次方程正解的存在性.     

Ginzburg-Landau方程的非齐次初边值问题

研究具非线性边界条件的一类广义Ginzburg-Landau方程解的整体存在性．推导了Ginzburg-Landau方程的非齐次初边值问题光滑解的几个积分恒等式,由此得到了解的法向导数在边界上的平方模以及解的平方模和导数的平方模估计;通过逼近技巧、先验估计和取极限方法证明了Ginzburg-Landau方程的非齐次初边值问题整体弱解的存在性．     

一类微分方程组的非齐次Sturm-Liouville边值问题解的存在性

在允许非线性项变号的情况下,利用锥上不动点定理,讨论了一类二阶非线性微分方程组的非齐次Sturm-Liouville边值问题解的存在性,得到了至少一个解及正解存在的多个存在性定理．     

数学年刊第27卷B辑第5期(2006)目次和提要

非齐次相对论欧拉方程组柯西问题的整体熵解李亚纯王安娇对理想流体的2×2非齐次相对论欧拉方程组进行了分析,对低阶源项提出了适当的条件,并在这些条件下建立了柯西问题整体熵解的存在性．     

分数阶扩散方程半无界混合问题的解

研究了一维半无界分数阶扩散方程具有第三类非齐次边条件的混合问题．分别给出具有第三类齐次边条件的混合问题基本解以及具有零初始条件的混合问题基本解．最后得到分数阶扩散方程半无界混合问题的求解公式．     

一阶拟线性非齐次偏微分方程存在整体光滑解的条件

在文献[1],[2]中讨论了一阶拟线性齐次偏微分方程 Cauchy 问题(1)(2)关于整体光滑解的存在性问题.文献[1]得到了λ_i=λ_i(u)时 Cauchy 问题(1)、(2)存在整体光滑解的充要条件;文献[2]进而得到了λ_i=λ_i(t,x,u)时 Cauchy 问题(1)、(2)存在整体光滑解的充要条件。本文将用[1]、[2]的思想方法,讨论一阶拟线性非齐次偏微分方程 Cauchy 问题     

含距离位势的拟线性椭圆方程解的存在性

变分原理证明了一类含距离位势的拟线性椭圆方程齐次Dirichlet边界条件下第一特征值问题的可解性.进一步,利用临界点理论得到了一类含距离位势的非线性椭圆方程非平凡解的存在性.     

高阶线性微分方程的解及其解的导数的不动点

研究了复域齐次和非齐次线性微分方程的解及其解的导数的不动点与超级问题,得到了整函数系数的齐次和非齐次线性微分方程的解及其解的导数的不动点的两个结果,所得结果推广了一些相关结果.     

Solution of Tikhonov’s Motion-Separation Problem Using the Modified Newton–Kantorovich Theorem

The paper presents a new way to prove the existence of a solution of the well-known Tikhonov’s problem on systems of ordinary differential equations in which one part of the variables performs “fast” motions and the other part, “slow” motions. Tikhonov’s problem has been the subject of a large number of works in connection with its applications to a wide range of mathematical models in natural science and economics. Only a short list of publications, which present the proof of the existence of solutions in this problem, is cited. The aim of the paper is to demonstrate the possibility of applying the modified Newton–Kantorovich theorem to prove the existence of a solution in Tikhonov’s problem. The technique proposed can be used to prove the existence of solutions of other classes of problems with a small parameter.     

GLOBAL EXISTENCE, UNIQUENESS, AND STABILITY FOR A NONLINEAR HYPERBOLIC-PARABOLIC PROBLEM IN PULSE COMBUSTION

A global existence theorem is established for an initial-boundary value problem,with time-dependent boundary data,arising in a lumped parameter model of pulse combustion; the model in question gives ri...     

On the existence of values for arbitration games

Two-person games in normal form are considered, where the players may use correlated strategies and where the problem arises, which Pareto optimal point in the payoff region to choose. We suppose that the players solve this problem with the aid of an arbitration function, which is continuous and profitable, and for which the inverse image of each Pareto point is a convex set. Then the existence of values and defensive ε-optimal strategies is discussed. Existence theorems are derived, using families of suitable dummy zero-sum games. The derived existence theorems contain all known existence results as special cases.     

Floating Drops and Functions of Bounded Variation

A variational problem for three fluids in which gravitational and surface tension forces are in equilibrium is studied using sets of finite perimeter and functions of bounded variation. Existence theorems are proven which imply the existence of an axisymmetric floating drop. This problem has been studied previously as a free boundary problem for axisymmetric capillary surfaces by Elcrat, Neel and Siegel, but the general existence problem for arbitrary drop volumes was left open. The results presented here settle a version of this question.     

拓扑向量空间中带上下界均衡问题解的存在性

主要研究了拓扑空间上的带上下界均衡问题和带限制条件的上下界均衡问题解的存在性.在非凸集上借助转移紧闭值等有关概念研究其相应均衡问题解的存在性,与一些作者的研究思路较为不同,得到了相应均衡问题解的存在条件,推广了一些作者在凸集上研究的相应结果,并且为相应均衡问题研究提供了一个新的视角.     

Global solvability of the problem on the motion of two fluids without surface tension

Unsteady motion of viscous incompressible fluids is considered in a bounded domain. The liquids are separated by an unknown interface on which the surface tension is neglected. This motion is governed by an interface problem for the Navier-Stokes system. First, a local existence theorem is established for the problem in Hölder classes of functions. The proof is based on the solvability of a model problem for the Stokes system with a plane interface, which was obtained earlier. Next, for a small initial velocity vector field and small mass forces, we prove the existence of a unique smooth solution to the problem on an infinite time interval. Bibliography: 7 titles.     

Spectral scale of self-adjoint operators and trace inequalities

Two mathematical models are presented which yield some mechanical aspects of this elastoplastic plate bending. The frist model proves insufficient if the classical Sobolev space framework is kept up. With the second model, an existence result for the transverse displacement problem formulation is obtained when the load does not exceed a specific critical value. The study of the stability problem leads to differentiation of a projector on a closed convex set, which is a difficult question; nevertheless, a hypothesis of regularity of the solution of some plasticity problem is introduced, and the existence of a critical load under which there is stability in Some sense is shown.     

On the Elliptic Equation △u ＋ K（x）e^2u -0 with K（x） Positive Somewhere

This paper considers the existence problem of an elliptic equation.which is equivalent to the prescribing conformal Gaussian curvature problem on R2.An existence result is pried.In particular,K(x)is allowed to be unbounded above.     

Optimal control of a two-dimensional contact problem

We consider a frictionless contact problem with unilateral constraints for a 2D bar. We describe the problem, then we derive its weak formulation, which is in the form of an elliptic variational inequality of the first kind. Next, we establish the existence of a unique weak solution to the problem and prove its continuous dependence with respect to the applied tractions and constraints. We proceed with the study of an associated control problem for which we prove the existence of an optimal pair. Finally, we consider a perturbed optimal control problem for which we prove a convergence result.     

On Solvability of Some Initial-Boundary Problems for Mathematical Models of the Motion of Nonlinearly Viscous and Viscoelastic Fluids

In the paper, the settings of initial-boundary and initial value problems arising in a number of models of movement of nonlinearly viscous or viscoelastic incompressible fluid are considered, and existence theorems for these problems are presented. In particular, the settings of initial-boundary value problems appearing in the regularized model of the movement of viscoelastic fluid with Jeffris constitutive relation are described. The theorems for the existence of weak and strong solutions for these problems in bounded domains are given. The initial value problem for a nonlinearly viscous fluid on the whole space is considered. The estimates on the right-hand side and initial conditions under which there exist local and global solutions of this problem are presented. The modification of Litvinov's model for laminar and turbulent flows with a memory is described. The existence theorem for weak solutions of initial-boundary value problem appearing in this model is given.