搜索结果: 136-150 共查到“常微分方程其他学科”相关记录150条 . 查询时间(0.627 秒)
三阶微分方程组边值问题常号解的存在性
三阶微分方程组 边值问题 常号解
2008/3/14
利用Krasnoselskii不动点定理,结合Leray-Schauder度,研究下列三阶微分方程组边值问题$$\left\{\begin{array}{ll}u_{i}^{'''}(t)=f_i(t,u_1(t),u_2(t),u_3(t)),\quad &t\in[0,1],\\%[2mm]u_i'(0)=u_i''(0)=u_i(1)=0, &i=1,2,3.\end{array}\righ...
一类2阶边值问题的分歧点
２阶边值问题 分歧点 强正线性算子
2008/3/14
8本文考虑以下２阶边值问题：其中．在关于Ａ，Ｂ；Ｐ，Ｑ，ｆ的一定条件下，证明了以上问题存在分歧点．所用的主要工具是Ｋｒａｓｎｏｓｅｌｓｋｉｉ的局部分歧定理与ＫｒｅｉｎＲｕｔｍａｎ定理．
非凸单个守恒律初边值问题的整体弱熵解的构造
非凸单个守恒律 初边值问题 边界熵条件
2008/3/14
本文研究具有两段常数的初始值和常数边界值的非凸单个守恒律的初边值问题. 在流函数具有一个拐点的条件下, 由相应的初始值问题弱熵解的结构和Bardos-Leroux-Nedelec提出的边界熵条件,给出初边值问题整体弱熵解的一个构造方法, 澄清弱熵解在边界附近的结构.与严格凸的单个守恒律初边值问题相比, 非凸单个守恒律初边值问题的弱熵解中包括下列新的相互作用类型:一个接触或非接触激波碰到边界...
利用单调迭代技巧和推广的 Mawhin 定理得到下述带有$p-$Laplacian 算子的多点边值问题迭代解的存在性, $$\left\{\ay\begin{array}{l} ({\it {\it {\it \Phi}}}_{p}(u'))'+f(t,u,Tu)=0,~~~~0\leq{t}\leq{1},\\ u(0)=\d\sum \limits _{i=1}^{q-1}\gamma _...
具有较高奇性的奇异边值问题的Dirichiet问题
奇异边值问题 锥 不动点
2008/3/14
本文讨论一类奇异二阶常微分方程的边值问题，其中非线性项ｆ（ｔ，ｕ）在ｕ＝０处及在ｔ＝０，１处都具有较高的奇性．应用现有的存在性结果无法得出这类方程的解．利用锥上的不动点定理及解的细致先验估计得到了正解的存在性．
摘要 给出了下列方程 $$u''(t)+f(u,t)u'(t)+g(u,t)=e(t)$$边值问题周期解的存在唯一性问题的一些新的判定条件.
摘要 设Ｘ，Ｙ为Ｂａｎａｃｈ空间，Ｄ（Ａ）Ｘ，Ａ：Ｄ（Ａ）→Ｙ为具有闭值域的闭稠定线性算子．本文不假设Ａ具有“定义域可分解”条件［１８］，引入Ａ的Ｍｏｏｒｅ－Ｐｅｎｒｏｓｅ广义逆Ａ＋．与Ｍ．Ｚ．Ｎａｓｈｅｄ引入的不同，Ａ＋一般非线性．本文在空间Ｘ，Ｙ的一定几何框架下，证得Ａ＋的存在唯一性、极小性、连续性，并给出了线性的充要条件，便于将Ａ＋应用于方程、优化、控制等问题．作为应用，本文第二部分利用Ｍｏ...
Multiple Positive Solutions for Nonlinear Third-Order Boundary Value Problems in Banach Spaces
Positive solutions boundary value problem Banach spaces fixed point index
2010/2/25
This paper deals with the positive solutions of nonlinear boundary value problems in Banach spaces. By using fixed point index theory, some sufficient conditions for the existence of at least one or t...
On Generalized Solution of a Class of Higher Order Operator-Differential Equations
Operator-differential equations Hilbert spaces existence of generalized solution
2010/2/25
In this paper the sufficient conditions on the existence and uniqueness of a generalized solution on the axis are obtained for higher order operator-differential equations, the main part of which is m...
Togethere with I Rodnianski we investigate the regularity of past boundaries of points in regular Einstein-vacuum spacetimes. We provide conditions, compatible with bounded L^2 curvature, which are su...
考察了1类非线性悬臂梁方程,在力学上,这类方程描述了1端固定,另1端自由的弹性梁的形变,本文中方程的特点是非线性项含有未知函数的三阶导数．通过使用方程的分解技巧和Leray—Schauder不动点定理建立了4个存在定理．主要结论表明只要非线性项在某个有界集上的“高度”是适当的,这类方程至少有1个解或者正解．
Spectral methods for the non cut-off Boltzmann equation and numerical grazing collision limit
Spectral methods Boltzmann equation cut-off assumption Fokker-Planck-Landau equation
2010/12/14
In this paper we study the numerical passage from the spatially homogeneous Boltzmann equation without cut-off to the Fokker-Planck-Landau equation in the socalled grazing collision limit.
Solving second order equations by extending the PS method
second order equations extending the PS method
2010/11/1
An extension of the ideas of the Prelle-Singer procedure to second order differential equations is proposed. As in the original PS procedure, this version of our method deals with differential equati...
A classification, according to invariant theory, of non-constant invariant Abel ODEs known as solvable and found in the literature is presented. A set of new integrable classes depending on one or no...
常微初值问题的自适应求解器AS的有效性
常微初值问题 自适应求解器AS
2010/5/7
In order to identify the effectiveness of the "AS" for solving stiff problems in O.D.Es 72 stiff problems adopted by Enright et al have been solved. The Numerical ttsts show that "AS" is dominant in c...