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1.
二阶非线性中立型时滞微分方程的振动性   总被引:3,自引:0,他引:3  
考虑二阶非线性中立型时滞分方程[a(t)|(z(t) p(t)x(t-τ))‘|^a-1(x(t) p(t)x(t-τ))‘]‘ q(t)|x(t-σ)|^a-1x(t-σ)=0(*)本文获得了方程(*)所有解振动的充分条件,推广并改进了[1]的结果。  相似文献   

2.
关于高阶中立型泛函微分方程的振动性   总被引:1,自引:0,他引:1  
本文研究了中立型泛函微分方程 d~n/dt~n[x(t)+cx(t-τ)]+p(t)x(t-σ)=0的振动性,这里c,τ,σ∈R,n≥2,τ≥0,σ≥0,p(t)是在[T,+∞)上的连续函数,且p(t)≥0,我们得到了在c≥0,一1≤c<0和c<一1等情况下方程振动的若干充分性条件.  相似文献   

3.
蒋建初 《数学杂志》2002,22(3):277-280
考虑二阶中立型时滞微分方程[a(t)|(x(t) p(t)x(t-τ))′|^α-1(x(t) p(t)x(t-τ))′]′ f(t,x(t-σ))=0(E)其中α,τ,σ是非负常数,a(t),p(t)∈C([t0,∞),R),f(t,x)∈C(R,R)。建立了方程(E)的一些新的振动条件。  相似文献   

4.
二阶非线性中立型微分方程的振动性   总被引:5,自引:0,他引:5  
研究中立型微分方程 [r(t) (y(t) p(t)y(t-τ) )′]′ q(t)f[y(t-σ) ]=0的振动性 .改进并推广了几个已有结果 .  相似文献   

5.
本文对较文[1,2]中更为广泛的具有非正系数的一类线性方程d/(dt)[x(t)+p(t)x(t-τ)]-Q(t)x(t-σ(t))=0,t≥t0及非线性方程d/(dt)[x(t)+p(t)x(t-τ(t))]-Q(t)f(x(t-σ(t)))=0,t≥t0进行了讨论,其中Q(t)∈C([t0,+∞).R+),得到了保证上述方程的所有有界解振动及非振动解当t→+∞时趋于零或±∞的一些充分性准则.  相似文献   

6.
具有多变时滞中立型微分方程的振动性   总被引:5,自引:0,他引:5  
考虑具有多变时滞中立型微分方程[x(t)-∑i=1^lpi(t)x(t-τi(t))]′ ∑j=1^mqj(t)x(t-σj(t))=0,获得了该方程所有解振动的几族充分条件.其中定理3的条件是“Sharp”条件,即当Pi(t),τi(t),qj(t),σj(t)(i=1,2,…,l,j=1,2,…,m)为常数时,条件是充分必要的.  相似文献   

7.
考虑二阶非线性中立型时滞微分方程(x(t)-p(t)x(t-τ))″+∑ from i=1 to n (qi(t)fi(x(t-σi)))=0,t0,其中p,q_i∈C(R+,R+),τ,σ_i∈(0,∞),f_i∈C(R,R),i=1,2,…,n,分别得到了方程所有解振动和方程存在非振动解的充分条件,推广和改进了相关文献中的相关结果.  相似文献   

8.
考虑中立型微分方程d^n/dt^n[x(t)-P(t)x(t-τ)] Q(t)x(t-σ)=0,t≥to,其中n≥1,n为奇数,P(t),Q(t)∈C([to, ∞),R^ )τ>0,σ>0。本在不需要通常假设∫^∞toQ(s)ds=∞的条件下,获得了保证(*)的所有解振动的几个充分条件,并推广了[1]、[3]的相应结论。  相似文献   

9.
二阶非线性中立型时滞微分方程的振动准则   总被引:1,自引:0,他引:1  
文章考虑二阶非线性中立型微分方程a(t)x(t)+∑li=1ci(t)x(t-τi(t))″+∑mi=1pi(t)fi(x(t-δi(t)))-∑ni=1qi(t)gi(x(t-σi(t)))=0的振动性,获得了该方程所有解振动的充分条件,推广了有关文献的结果.  相似文献   

10.
通过构造适当的变换及有效函数,研究了一阶中立型时滞微分方程[x(t)-c(t)x(t-r)]′+p(t)f(x(t-τ))+∑ni=1qi(t)}f(x(t-σi))=0的振动性,获得了此方程所有解振动的n族充分条件.  相似文献   

11.
12.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the'living world. In his seminal paper "The Chemical Basis of Morphogenesis", Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates(1990) on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing's prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows  相似文献   

13.
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   

14.
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   

15.
In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).  相似文献   

16.
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   

17.
18.
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   

19.
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   

20.
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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