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 共查询到20条相似文献,搜索用时 78 毫秒
1.
王志华  张凤祥 《数学研究》1998,31(2):169-175
我们在无限维空间中研究微分包含的生存W—单调轨道的存在性.基于Zorn引理,我们给出了一个逼近方法,在较弱的条件下得到了一个存在性定理,其特殊情形则包含了已有的生存定理和微分方程理论中的若干结果作为应用,我们首先研究了微分包含生存解的整体存在性,得到了整体生存理.然后我们研究了微分包含解的稳定性,得到一些新的结果.  相似文献   

2.
研究了一类发展包含的周期问题,其结果应用于建立一类半线性微分包含周期解的存在性定理.给出了半线性微分包含端点解的存在性定理和强松驰定理,并且应用于周期反馈控制系统.  相似文献   

3.
刘晓华  王志华 《数学研究》1997,30(2):142-145
本文研究Banach空间中含有非线性半群的非凸值泛函微分包含,证明了积分解的存在性,得到一个新的存在性定理.  相似文献   

4.
研究了一类积分微分包含的周期解,利用Kakutani不动点定理和Tichonoff不动点定理给出了凸和非凸两种情形下周期解存在的充分条件.  相似文献   

5.
倒向随机微分方程解的Malliavin微分   总被引:1,自引:0,他引:1  
讨论倒向随机微分方程Yt=ζ+∫^Ttg(s,Ys,Zs)ds-∫^TtZsdWs解在Malliavin微分意义下的可微性,并得到其Malliavin二阶微分仍然满足一个倒向随机微分方程。用迭代方法构造一个随机序列(Y^n.Z^n.),证明在Malliavin微分意义下二阶可微,同时证明了它在Sobolev空间D2,2则中收敛于一个线性倒向随机微分方程的解。  相似文献   

6.
利用逼近解的方法,解析预解算子理论和Kakutani不动点定理讨论了预解算子控制的非局部分数阶微分包含,获得了适度解的存在性定理.  相似文献   

7.
非凸集值映射的包含切性及应用   总被引:4,自引:1,他引:3  
杨富春 《数学学报》1996,39(5):659-665
本文在一般的Banach空间X中研究从非空闭集KX到X的非凸集值映射F的包含切性问题.得到的结果定理3.1把有关的结论推广到非光滑空间,定理3.3则将有限维空间的正则性定理推广到任意的Banach空间.作为结果的应用,我们证明了无穷维非凸微分包含和非凸控制系统生存解的存在性,且给出了一个方便的等价切性条件.  相似文献   

8.
研究一类微分包含9集值微分方程)x'(t)∈F(t,z),x(t0)=x0解的存在性,证明了解的存在和延拓定理。  相似文献   

9.
为获得一类微分包含与积分包含的多解存在性定理,我们应用集值映象不动点指数理论把著名的Amann三解定理等多解定理推广到集值映象,我们还用例子说明了所得结果.  相似文献   

10.
秦松喜 《数学研究》1999,32(1):83-85,91
利用不动点方法,证明了Banach-空间中右端项不连续的微分包含解的存在性.  相似文献   

11.
冯学尚  邵琨 《应用数学》1994,7(2):230-234
本文讨论由Ott E.等建立的机械模型,并给出了该模型初值问题存在整体性弱解的证明。  相似文献   

12.
In this paper, we study the solvability of the operator equations in the general setting of infinite-dimensional Hilbert space with corresponding operators no necessarily having closed range. We get the necessary and sufficient conditions for the existences of the solutions and obtain formulae in each case for the general selfadjoint, positive and real positive solutions to these operator systems.  相似文献   

13.
张克梅  孙经先 《数学学报》2007,50(6):1403-141
利用拓扑度理论及不动点指数理论,讨论了渐近线性算子方程的四种类型的解(即零解、正解、负解和变号解)的存在性,并将这一抽象结果应用于微分方程两点边值问题.  相似文献   

14.
Sufficient conditions have been obtained for the existence of at least two non-negative periodic solutions to a system of first-order nonlinear functional differential equations. Applications to some ecological models are given.  相似文献   

15.
This paper is concerned with a class of neutral difference equations of second order with positive and negative coefficients of the forms
where τ, δ and σ are nonnegative integers and {p n }, {q n } and {c n } are nonnegative real sequences. Sufficient conditions for oscillation of the equations are obtained. Research of the first author was supported by Department of Science and Technology, New Delhi, Govt. of India, under BOYSCAST Programme vide Sanc. No. 100/IFD/5071/2004-2005 Dated 04.01.2005.  相似文献   

16.
In this paper, we study the traveling wave solutions for a complex short-pulse equation of both focusing and defocusing types, which governs the propagation of ultrashort pulses in nonlinear optical fibers. It can be viewed as an analog of the nonlinear Schrodinger (NLS) equation in the ultrashort-pulse regime. The corresponding traveling wave systems of the equivalent complex short-pulse equations are two singular planar dynamical systems with four singular straight lines. By using the method of dynamical systems, bifurcation diagrams and explicit exact parametric representations of the solutions are given, including solitary wave solution, periodic wave solution, peakon solution, periodic peakon solution and compacton solution under different parameter conditions.  相似文献   

17.
In this paper, we consider the axi-symmetric flow between two infinite stretching disks. By using a similarity transformation, we reduce the governing Navier-Stokes equations to a system of nonlinear ordinary differential equations. We first obtain analytical solutions via a four-term perturbation method for small and large values of the Reynolds number R. Also, we apply the Homotopy Analysis Method (which may be used for all values of R) to obtain analytical solutions. These solutions converge over a larger range of values of the Reynolds number than the perturbation solutions. Our results agree well with the numerical results of Fang and Zhang [22]. Furthermore, we obtain the analytical solutions valid for moderate values of R by use of Homotopy Analysis.  相似文献   

18.
This paper presents the vortical and self-similar solutions for 2D compressible Euler equations using the separation method. These solutions complement Makino’s solutions in radial symmetry without rotation. The rotational solutions provide new information that furthers our understanding of ocean vortices and reference examples for numerical methods. In addition, the corresponding blowup, time-periodic or global existence conditions are classified through an analysis of the new Emden equation. A conjecture regarding rotational solutions in 3D is also made.  相似文献   

19.
盛兴平 《大学数学》2005,21(2):107-110
给出了矩阵方程AXB=D相容的又一充要条件,同时讨论它的极小范数解、最小二乘解和极小范数最小二乘解,推广了文献[1]和[3]的结论.  相似文献   

20.
The dynamics and bifurcations of traveling wave solutions are studied for three nonlinear wave equations. A new phenomenon, such as a composed orbit, which consists of two or three heteroclinic orbits, may correspond to a solitary wave solution, a periodic wave solution or a peakon solution, is found for the equations. Some previous results are extended.  相似文献   

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