首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 54 毫秒
1.
该文利用Krasnoselskii不动点定理和Schwarz不等式, 获得了关于非自治的广义单种群Logistic模型 x=x(t){a(t)-b(t)x(t)-∑ni=1ci (t)x(t-τi(t))-∫0-∞k(t, s)x(t+s)ds} 的正周期解的存在性和唯一性的一些新的结果.  相似文献   

2.
主要研究了一种新型时滞积分不等式u(t)≤a(t)+∫0α(t)f(t,s)w(u(s))ds+∫0α(t)g(t,s∫)0sh(s,τ)φ(u(τ))dτds up(t)≤a(t)+p/p-q∫0α(t)(f(t,s)uq(s)w(u(s))+g(t,s)uq(s))dsup(t)≤a(t)+p/p-q∫0α(t)f(t,s)uq(s)w(u(s))ds+p/p-q∫0tg(t,s)uq(s)w(u(s))ds这里p>q≥0是常数且t∈[0,∞).并且用此结果研究了时滞微分积分方程解的全局存在性和有界性.  相似文献   

3.
对于非线性抛物型方程其中QT=Ω×(0,T)是上半空间R+n+1中的一个柱形区域,ST=Ω×[0,T]是Q_T的侧面,Ω是R~n中的一个有界区域,其边界Ω充分光滑,本文着重讨论函数ai(x,t,u,s)和a(x,t,u,s)关于变元s=(s1…,sn)按指数形式快速增长的情形.文中得到了强非线性抛物型方程(1.1)和(1.2)在空间中广义解的存在性.这个结果也包括了ai(x,t,u,s)及a(x,t,u,s)关于变元s=(s1..,sn)按幂次|s|n的形式增长的情形,改正了Ladyenskaja等的文献中第五章定理6.7的证明中的一个疏忽。  相似文献   

4.
冯敬海  沙震 《中国科学A辑》1997,40(12):1096-1100
设随机过程x(t)(t∈[0,∞))是一个从属过程,X[0,1]=|x∈R:t∈[0,1],X(t)=x}.通过对x(t)的指标函数g(u)(u≥0)的细致分析得到了关于X[0,1]填充测度函数的判别准则.事实上,若φ(s)(s∈(0,1))为任一测度函数,记h(s)=φ(s)/g(1/s),则有:h-p(x|0,1|= 相应于∫10φ2(s)/s ds{<+∞ =+∞  相似文献   

5.
In this paper we study the oscillation of the retarded differential equation x′(t)+∫abp(t,ξ)x[g(t,ξ)]dσ(ξ)=0 (b>a) (1)and the advanced differential equation x′(t)-∫abp(t,ξ)x[g(t,ξ)]dσ(ξ)=0 (b>a) (2) We improved the main results of [1-4].  相似文献   

6.
本文考虑Banach空间是形如x(t)=u(t)+∫Gtf(t,s,x(s))ds的广义Volterra积分方程,利用M?nch不动点定理得到所论方程解的某些存在定理.  相似文献   

7.
该文运用锥上的不动点定理研究非线性二阶常微分方程无穷多点边值问题 u'+a (t ) f (u)=0, t∈(0, 1), u(0)=0, u(1)=∑i =1α i u ( ξ i ) 正解的存在性. 其中ξ i∈ (0,1),α i∈ [0,∞), 且满足∑i=1αiξ i <1.α∈C([0,1], [0,)),f∈C ([0,∞), [0,∞)).  相似文献   

8.
Theorem. A mapping x** of X* into sealar field Φ is a linear functional if and only if there exists a μ∈ba(S) such that X**(X*)=∫sx*(s)μ(ds),x*∈X* Theorem. F∈ba(S.Σ)* if and only if there exists a λ∈ba (T) (T is the closed unit sphere of the space B(S,Σ))such that F(μ)=∫(∫st(s)μ(ds))λ(dt),μ∈ba(S,Σ).  相似文献   

9.
研究了一种新型不连续函数的积分不等式um(t)≤φ(t)+m-m n∫tt0f(s)un(s)w(u(s))ds+t0∑相似文献   

10.
投影下的Gronwall不等式   总被引:7,自引:1,他引:6  
本文对J.K.Hale曾提出的一类广泛的投影下的Gronwal不等式问题作了讨论,对满足u(t)≤a(t)+∫tb(t-s)u(s)ds+∫c(s)u(t+s)ds,(?)t≥0的函数u(t)∈Cb0(R+,R+)作了估计.其结果对讨论微分方程的有界解、不变流形及其Foliation和进一步讨论奇性Gronwal不等式都有意义  相似文献   

11.
12.
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   

15.
16.
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   

19.
Résumé On décrit toutes les feuilles des laminations minimales dont un ensemble résiduel de feuilles ont 2 bouts.   相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号