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1.
变系数Euler-Bernoulli梁振动发展系统的存在性   总被引:1,自引:0,他引:1  
讨论变系数Euler-Bernoulli梁振动系统{uu(x,t) η(t)uxxxx(x,t)=0,0<x<1,0≤t≤T u(0,t)=ux(0,t)=0,0≤t≤t -uxxx(1,t) muu(1,t)=-αu1(1,t) βuxxx(1,t),0≤t≤T uxt(1,t) =-γuxx(1,t),0≤t≤t u(x,0)=u1(x),u1(x,0),0≤x≤1证明了该系统产生一个发展系统.  相似文献   

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研究三维微分系统:u′1=a1(t)|u2|λ1sgn u2,u′2=a2(t)|u3|λ2sgn u3,u′3=-a3(t)|u1|λ3sgn u1.假设λi(i=1,2,3)是正的常数,ai(t)(i=1,2,3)在区间[0,∞)上是正的连续函数,根据u的分量ui的特殊渐近条件定义了正值解的几种类型。系统满足条件∫0∞ai(t)dt=∞,i=1,2.  相似文献   

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本文利用临界点理论中的山路引理,证明了二阶 Hamilton 系统ü-L(t)u+W1u(t,u)=0存在非平凡的同宿轨道,其中L(t)y.y≥λy2,y∈Rn,λ>0,L(t)和W(t,u)关于变量t没有周期性假设.  相似文献   

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利用重合度理论中的延拓定理和微分积分不等式讨论具有无穷时滞的中立型积分微分系统其中x(t)=(x1(t),…,xn(t))T,G∈C2(Rn,R),f∈C(R×R×Rn×Rn,Rn),e∈C(R,Rn),e(t ω)≡e(t),f(t ω,u ω,x,y)≡f(t,u,x,y),f(t,u,0,0)≡0,t,u∈R,x,y∈Rn,ω>0为常数,获得了该系统平稳振荡的易于检验的判别条件.  相似文献   

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本文讨论实轴上的与Cahn-Hilliard方程有联系的一类四阶非线性抛物型方程Эu/Эt σЭ^4u/Эx^4 αu uЭu/Эx g(u)=f(x,t)的长时间行为。在外力f(x,t)是时间t的拟周期函数,非线性项g(u)满足一定的条件下,通过引入过程的概念,证明系统存在一致吸引子,并给出吸引子维数的上界估计。  相似文献   

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运用变分方法讨论二阶渐近周期Hamilton系统 -u+L(t)u=(1+g(t))V′(t,u)的Lagrange泛函在流形上的极小问题,进而证明该系统存在非平凡同宿轨道,其中L,V关于t是周期的,g(t)→0(|t|→∞).  相似文献   

7.
共振下非保守系统边值问题解的存在唯一性   总被引:1,自引:0,他引:1  
利用minmax原理的非变分形式,证明了共振下非保守的二阶微分方程系统u′′(t)+Au′(t)+G(u,t)=e(t)边值问题解的存在唯一性定理.  相似文献   

8.
利用minmax原理的非变分形式,证明了共振下非保守的二阶微分方程系统u′′(t)+Au′(t)+ G(u,t)=e(t)边值问题解的存在唯一性定理.  相似文献   

9.
考虑二阶三点边值问题系统-u"=f(t,v),t∈(0,1),-v"=g(t,u),t∈(0,1),u(0)=αu(η),u(1)=βu(η),v(0)=αv(η),v(1)=βv(η),其中f,g∈C([0,1]×R+,R+),g(t,0)(=)0,η∈(0,1)且0<β≤α<1.首先给出了线性边值问题的Green函数;其次,给出了Green函数的一些很好的性质;最后,运用锥上拉伸与压缩不动点定理研究了上述边值问题系统至少一个或多个正解的存在性.  相似文献   

10.
考虑了非线性三阶三点边值问题u′′′(t)=f(t,u(t))+g(t,u(t)),0t1,u(0)=u′(η)=u′′(1)=0的正解.本文中g(t,u)可以在t=0,t=1及u=0处奇异,而且允许g(t,u)关于u不是非减的.通过构造适当的控制函数并且利用锥上的Guo-Krasnoselskii不动点定理,证明了若干新的局部存在定理.  相似文献   

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Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

13.
We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.  相似文献   

14.
It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.  相似文献   

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正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   

17.
正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.  相似文献   

18.
A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].  相似文献   

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