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1.
Let
  相似文献   

2.
具时滞的奇异(n-1,1)共轭边值问题的多重正解   总被引:2,自引:0,他引:2  
Abstract. This paper discusses the singular (n-l, 1) conjugate boundary value problem as fol-lows by using a fixed point index theorem in cones  相似文献   

3.
Some results concerning existence of positive solutions for the singular boundary value problems u^(4)(t)=f(t,u(t)) t∈(0,1) u(0)=u(1)=0 u‘(0)=u‘(1)=0 have been given, where f(t, x) may be singular at t = 0, 1.  相似文献   

4.
Let D be a bounded domain in an n-dimensional Euclidean space Rn. Assume that 0 < λ1 ≤λ2 ≤ … ≤ λκ ≤ … are the eigenvalues of the Dirichlet Laplacian operator with any order l{(-△)lu=λu, in D u=(δ)u/(δ)(→n)=…(δ)l-1u/(δ)(→n)l-1=0,on (δ)D.Then we obtain an upper bound of the (k 1)-th eigenvalue λκ 1 in terms of the first k eigenvalues.k∑i=1(λκ 1-λi) ≤ 1/n[4l(n 2l-2)]1/2{k∑i=1(λκ 1-λi)1/2λil-1/l k∑i=1(λκ 1-λi)1/2λ1/li}1/2.This ineguality is independent of the domain D. Furthermore, for any l ≥ 3 the above inequality is better than all the known results. Our rusults are the natural generalization of inequalities corresponding to the case l = 2 considered by Qing-Ming Cheng and Hong-Cang Yang. When l = 1, our inequalities imply a weaker form of Yang inequalities. We aslo reprove an implication claimed by Cheng and Yang.  相似文献   

5.
It is proved that the boundary-value problem
, has a solution, provided that the following conditions are fulfilled:
, and, for ϕ(u) ≡ 0, the Galerkin method converges in the norm of the space H1(a, b; a). Several theorems of a similar kind are presented. Bibliography: 4 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 334, 2006, pp. 246–266.  相似文献   

6.
The initial boundary value problem
$ {*{20}{c}} {\rho {u_{tt}} - {{\left( {\Gamma {u_x}} \right)}_x} + A{u_x} + Bu = 0,} \hfill & {x > 0,\quad 0 < t < T,} \hfill \\ {u\left| {_{t = 0}} \right. = {u_t}\left| {_{t = 0}} \right. = 0,} \hfill & {x \geq 0,} \hfill \\ {u\left| {_{x = 0}} \right. = f,} \hfill & {0 \leq t \leq T,} \hfill \\ $ \begin{array}{*{20}{c}} {\rho {u_{tt}} - {{\left( {\Gamma {u_x}} \right)}_x} + A{u_x} + Bu = 0,} \hfill & {x > 0,\quad 0 < t < T,} \hfill \\ {u\left| {_{t = 0}} \right. = {u_t}\left| {_{t = 0}} \right. = 0,} \hfill & {x \geq 0,} \hfill \\ {u\left| {_{x = 0}} \right. = f,} \hfill & {0 \leq t \leq T,} \hfill \\ \end{array}  相似文献   

7.
This paper is concerned with a nonlocal hyperbolic system as follows utt = △u + (∫Ωvdx )^p for x∈R^N,t〉0 ,utt = △u + (∫Ωvdx )^q for x∈R^N,t〉0 ,u(x,0)=u0(x),ut(x,0)=u01(x) for x∈R^N,u(x,0)=u0(x),ut(x,0)=u01(x) for x∈R^N, where 1≤ N ≤3, p ≥1, q ≥ 1 and pq 〉 1. Here the initial values are compactly supported and Ω belong to R^N is a bounded open region. The blow-up curve, blow-up rate and profile of the solution are discussed.  相似文献   

8.
Sufficient conditions of solvability and unique solvability of the boundary value problem are established, where are measurable functions and the vector function is measurable in the first and continuous in the last kmn arguments; moreover, this function may have nonintegrable singularities with respect to the first argument.  相似文献   

9.
We study the convergence of a sequence of approximate solutions for thefollowing higher-order nonlinear periodic boundary–value problem:
Here, is such that,for some k 1, exists and isa continuous function for i=0, 1, . . . , k. We prove thatit is possible to construct two sequences of approximate solutionsconverging to the extremal solution with rate of convergence of order k.  相似文献   

10.
This paper is concerned with a class of even order nonlinear damped differential equations
where n is even and tt 0. By using the generalized Riccati transformation and the averaging technique, new oscillation criteria are obtained which are either extensions of or complementary to a number of existing results. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

11.
We study the existence of a solution to the nonlinear fourth-order elastic beam equation with nonhomogeneous boundary conditions
$\left\{ \begin{gathered} u^{(4)} (t) = f(t,u(t),u'(t),u'(t),u'(t)),a.e.t \in [0,1], \hfill \\ u(0) = a,u'(0) = b,u(1) = c,u'(1) = d, \hfill \\ \end{gathered} \right. $\left\{ \begin{gathered} u^{(4)} (t) = f(t,u(t),u'(t),u'(t),u'(t)),a.e.t \in [0,1], \hfill \\ u(0) = a,u'(0) = b,u(1) = c,u'(1) = d, \hfill \\ \end{gathered} \right.   相似文献   

12.
Based on the coincidence degree theory of Mawhin, we get a new general existence result for the following higher-order multi-point boundary value problem at resonance
$\begin{gathered} x^{(n)} (t) = f(t,x(t),x'(t),...,x^{(n - 1)} (t)),t \in (0,1), \hfill \\ x(0) = \sum\limits_{i = 1}^m {a_i x(\xi _i ),x'(0) = ... = x^{(n - 2)} (0) = 0,x^{(n - 1)} (1) = } \sum\limits_{j = 1}^l {\beta _j x^{(n - 1)} (\eta _j )} , \hfill \\ \end{gathered} $\begin{gathered} x^{(n)} (t) = f(t,x(t),x'(t),...,x^{(n - 1)} (t)),t \in (0,1), \hfill \\ x(0) = \sum\limits_{i = 1}^m {a_i x(\xi _i ),x'(0) = ... = x^{(n - 2)} (0) = 0,x^{(n - 1)} (1) = } \sum\limits_{j = 1}^l {\beta _j x^{(n - 1)} (\eta _j )} , \hfill \\ \end{gathered}   相似文献   

13.
In the present paper, the following Dirichlet problem and Neumann problem involving the p-Laplacian
((1.λ))
and
((2.λ))
are studied and some new multiplicity results of solutions for systems (1.λ) and (2.λ) are obtained. Moreover, by using the KKM principle we give also two new existence results of solutions for systems (1.1) and (2.1). This Work is supported in part by the National Natural Science Foundation of China (10561011).  相似文献   

14.
Let D be an increasing sequence of positive integers, and consider the divisor functions: d(n, D) =∑d|n,d∈D,d≤√n1, d2(n,D)=∑[d,δ]|n,d,δ∈D,[d,δ]≤√n1, where [d,δ]=1.c.m.(d,δ). A probabilistic argument is introduced to evaluate the series ∑n=1^∞and(n,D) and ∑n=1^∞and2(n,D).  相似文献   

15.
16.
We investigate limiting behavior as γ tends to ∞ of the best polynomial approximations in the Sobolev-Laguerre space WN,2([0, ∞); e−x) and the Sobolev-Legendre space WN,2([−1, 1]) with respect to the Sobolev-Laguerre inner product
and with respect to the Sobolev-Legendre inner product
respectively, where a0 = 1, ak ≥0, 1 ≤kN −1, γ > 0, and N ≥1 is an integer.  相似文献   

17.
For functions satisfying the boundary conditions
, the following inequality with sharp constants in additive form is proved:
wheren≥2, 0≤1≤n−2,−1≤m≤1, m+1≤n−3, and1≤p,q,r≤∞. Translated fromMatematicheskie Zametki, Vol. 62, No. 5, pp. 712–724, November, 1997. Translated by N. K. Kulman  相似文献   

18.
In this paper, we consider the multiple existence of nonradial positive solutions of coupled nonlinear Schr?dinger system
where μ1, μ2 > 0 with and β < 0. It is known that the solutions of (P) is not necessarily radial [12]. We show that problem (P) has multiple nonradial solutions in case that |β| is sufficiently small.   相似文献   

19.
We offer sufficient conditions for the existence of solutions for the boundary value problem $\begin{gathered} y(n) + f(t,y,y^1 ,...,y^{(n - 2)} = 0, 0< t< 1, n \geqslant 2 \\ y^{(i)} (0) = 0, 0 \leqslant i \leqslant n - 3 \\ y^{(n - 2)} (0) - \beta y^{(n - 1)} (0) = 0 \\ \gamma y^{(n - 2)} (1) + \delta y^{(n - 1)} (1) = 0 \\ \end{gathered} $ where α, β, γ and δ are constants satisfying αγ+αδ+βγ>0, β, δ≥0, β+α>0 and δ+γ>0.  相似文献   

20.
§ 1  IntroductionRecently,certain three-point boundary value problems for nonlinear ordinarydifferential equations have been studied by many authors[1— 6] .However,few papers havebeen published on the same problems for nonlinear functional differential equations.In thispaper,we are concerned with the following second order differential equation with anadvanced argumentu″(t) +λa(t) f(u(h(t) ) ) =0 ,t∈ (0 ,1 ) (1 .1 )with the three-point boundary conditionsu(0 ) =0 ,αu(η) =u(1 ) ,(1 .2 )…  相似文献   

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