共查询到20条相似文献,搜索用时 30 毫秒
1.
研究了非线性抛物方程在非线性边界条件下的解的爆破问题,通过构造一个能量表达式,运用微分不等式的方法,得到该能量表达式所满足的微分不等式,然后通过积分得到当爆破发生时解在非线性边界条件下的爆破时间的下界. 相似文献
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考虑了一个二阶奇摄动非线性边值问题,利用匹配展开法研究了该问题的激波解,讨论了该问题的激波位置与边界条件的关系. 相似文献
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考虑了一个具有内部物质对流和非线性边界热交换的多维连铸Stefan问题,并得到了这个问题整体弱解的存在性、唯一性和对初边界条件的连续依赖性。本项工作改进和推广了J.F.Fodri-gues&F.Yi的结果,放宽了他们对内部流和边界条件的一些不太符合实际的限制。 相似文献
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张隆孔凡亮邢喜民徐加波 《数学的实践与认识》2022,(11):189-196
研究了带有柯布道格拉斯生产函数边界条件的非线性资产投资系统的定解问题,通过将依赖资产总量的非线性问题转化为一个算子的不动点的存在唯一性问题,利用Banach空间不动点原理得到了方程解的存在唯一性,讨论了模型解关于外资项的连续依赖性及解的性质. 相似文献
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在本文我们讨论了在等值面边值问题中的非线性边界条件的均匀化,推广了相应的边界条件均匀化结果,而且可应用到用于处理热敏电阻问题中的一类非线性非局部边值问题的边界条件均匀化问题。 相似文献
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Yuan Di Wang 《数学学报(英文版)》2001,17(2):197-206
Recently much work has been devoted to nonlocal problems. However, very little has been accomplished in the literature for
nonlocal initial problems with nonlinear boundary conditions. It is the purpose of this paper to prove the existence results
for solutions to a semilinear parabolic PDE with linear homogeneous boundary conditions, and to other ones with nonlinear
boundary conditions, provided the ordered upper and lower solutions are given. Semigroup, fractional order function spaces
and generalized Poincaré operators play an important role in proving the existence of solutions.
Supportedpartly by Research Grant 19531060 of China NSF and Grant 97024811 of the Foundation of Doctoral
Program 相似文献
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J.R.L. Webb 《Applied mathematics and computation》2010,216(2):497-500
We show that it is important to allow the nonlinear term to change sign when discussing existence of a positive solution for multipoint, or more general nonlocal, boundary value problems in the resonant case. When the nonlinear term has a fixed sign we obtain simple necessary and sufficient conditions for the existence of positive solutions. 相似文献
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《Nonlinear Analysis: Theory, Methods & Applications》2005,62(7):1251-1265
In this paper we study the existence of positive solutions to a system of second-order nonlocal boundary value problems by using fixed point index theory in a cone. Our hypotheses imposed on nonlinearities are those which characterize systems of nonlocal boundary value problems, and our boundary value conditions are expressed in terms of possibly nonlinear functions of Riemann–Stieltjes integrals, thus generalizing and unifying the boundary value conditions in the literature. Therefore our results cannot be routinely deduced from the ones for single nonlocal problem in the literature. 相似文献
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本文旨在讨论一个线性非局部方程和相应非线性方程解存在的条件,对非局部积分核作一定限制后,得到在积分核变号条件下解的存在唯一性结果。 相似文献
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主要研究在Dirichlet边界条件或Neumann边界条件下的一类非局部非线性的扩散方程问题.在适当的假设下,证明解的存在性、唯一性、比较原则、以及解对初边值条件的连续依赖性,并就给定的初边值条件,证明解在有限时刻全局爆破. 相似文献
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M. Bogoya R. Ferreira J.D. Rossi 《Journal of Mathematical Analysis and Applications》2008,337(2):1284-1294
We deal with boundary value problems (prescribing Dirichlet or Neumann boundary conditions) for a nonlocal nonlinear diffusion operator which is analogous to the porous medium equation. First, we prove existence, uniqueness and the validity of a comparison principle for these problems. Next, we impose boundary data that blow up in finite time and study the behavior of the solutions. 相似文献
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The main purpose of this paper is the existence of solutions and controllability for semilinear boundary problems with nonlocal initial conditions. We show that the solutions are given by a variation of constants formula which allows us to study the exact controllability for this kind of problems with control and nonlinear terms at the boundary. The included application to a size structured population equation provides a motivation for abstract results. 相似文献
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A class of nonlinear reaction-diffusion systems is considered. We formulate some automatic control problems based on feedback
devices located on the boundary. Two different types of devices are analyzed: relay switch and Preisach hysteresis operator.
The resulting models lead to a nonlinear integrodifferential parabolic system with nonlinear and nonlocal boundary conditions.
We prove global existence and uniqueness of solutions in both the cases considered. 相似文献
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C.V. Pao 《Journal of Mathematical Analysis and Applications》2010,372(2):351-399
This paper is concerned with a class of fourth-order nonlinear elliptic equations with nonlocal boundary conditions, including a multi-point boundary condition in a bounded domain of Rn. Also considered is a second-order elliptic equation with nonlocal boundary condition, and the usual multi-point boundary problem in ordinary differential equations. The aim of the paper is to show the existence of maximal and minimal solutions, the uniqueness of a positive solution, and the method of construction for these solutions. Our approach to the above problems is by the method of upper and lower solutions and its associated monotone iterations. The monotone iterative schemes can be developed into computational algorithms for numerical solutions of the problem by either the finite difference method or the finite element method. 相似文献
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研究了一类广义抛物型方程奇摄动问题.首先在一定的条件下, 提出了一类具有两参数的非线性非局部广义抛物型方程初始 边值问题.其次证明了相应问题解的存在性.然后, 通过Fredholm积分方程得到了初始 边值问题的外部解.再利用泛函分析理论和伸长变量及多重尺度法, 分别构造了初始 边值问题广义解的边界层、初始层项,从而得到了问题的形式渐近展开式.最后利用不动点理论证明了对应的非线性非局部广义抛物型方程的奇异摄动初始 边值问题的广义解的渐近展开式的一致有效性. 相似文献