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 31 毫秒
1.
We study the first boundary-value problem for the following mixed-type equation of the second kind:
$ u_{xx} + yu_{yy} + au_y - b^2 u = 0 $ u_{xx} + yu_{yy} + au_y - b^2 u = 0   相似文献   

2.
Extensions of some inequalities   总被引:2,自引:0,他引:2  
Abstract. By using a simple analytic method the following inequalities are proved:  相似文献   

3.
By using the Riccati transformation and mathematical analytic methods,some sufficient conditions are obtained for oscillation of the second-order quasilinear neutral delay difference equations Δ[r n |Δz n | α-1 Δ z n ] + q n f (x n-σ)=0,where z n=x n + p n x n τ and ∞ Σ n=0 1 /r n 1/α < ∞.  相似文献   

4.
Some new oscillation criteria for nonlinear delay difference equation with damping △^2xn+pn△xn+F(n,x(n-τ,△x(n-σ)=0,n=0,1,2,…,(*)are given. Our results partially solve the open problem posed in [Math. Bohemica, 125 (2000), 421- 430]. Also, we will establish some new oscillation criteria for special cases of (*), which improve some of the well-known results in the literature.  相似文献   

5.
We study existence and multiplicity of homoclinic type solutions to the following system of diffusion equations on \mathbbR ×W{\mathbb{R}} \times \Omega :
$ \left\{ {{*{20}c} {\,\,{\partial}_t u - {\Delta}_x u + b(t,x) \cdot {\nabla}_x u + V(x)u = H_v (t,x,u,v),} \\ { - {\partial}_t v - {\Delta}_x v - b(t,x) \cdot {\nabla}_x v + V(x)v = H_u (t,x,u,v),}\\ } \right. $ \left\{ {\begin{array}{*{20}c} {\,\,{\partial}_t u - {\Delta}_x u + b(t,x) \cdot {\nabla}_x u + V(x)u = H_v (t,x,u,v),} \\ { - {\partial}_t v - {\Delta}_x v - b(t,x) \cdot {\nabla}_x v + V(x)v = H_u (t,x,u,v),}\\ \end{array} } \right.   相似文献   

6.
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   

7.
The paper deals with positive solutions of a nonlocal and degenerate quasilinear parabolic system not in divergence form
$ u_t = v^p \left( {\Delta u + a\int_\Omega {udx} } \right),v_t = u^q \left( {\Delta v + b\int_\Omega {vdx} } \right) $ u_t = v^p \left( {\Delta u + a\int_\Omega {udx} } \right),v_t = u^q \left( {\Delta v + b\int_\Omega {vdx} } \right)   相似文献   

8.
The existence of a positive solution for the generalized predator-prey model for two species
$ \begin{gathered} \Delta u + u(a + g(u,v)) = 0in\Omega , \hfill \\ \Delta v + v(d + h(u,v)) = 0in\Omega , \hfill \\ u = v = 0on\partial \Omega , \hfill \\ \end{gathered} $ \begin{gathered} \Delta u + u(a + g(u,v)) = 0in\Omega , \hfill \\ \Delta v + v(d + h(u,v)) = 0in\Omega , \hfill \\ u = v = 0on\partial \Omega , \hfill \\ \end{gathered}   相似文献   

9.
The authors study the existence of homoclinic type solutions for the following system of diffusion equations on R × RN:{■tu-xu + b ·▽xu + au + V(t,x)v = Hv(t,x,u,v),-■tv-xv-b·▽xv + av + V(t,x)u = Hu(t,x,u,v),where z =(u,v):R × RN → Rm × Rm,a > 0,b =(b1,···,bN) is a constant vector and V ∈ C(R × RN,R),H ∈ C1(R × RN × R2m,R).Under suitable conditions on V(t,x) and the nonlinearity for H(t,x,z),at least one non-stationary homoclinic solution with least energy is obtained.  相似文献   

10.
Ibαf ( x) =∫R ∏mj=1( bj( x) - bj( y) ) 1| x - y| n-αf ( y) dyare considered.The following priori estimates are proved.For 1 01Φ1t| {y∈Rn:| Ibαf( y) | >t}| 1q ≤csupt>01Φ1t| {y∈Rn:ML( log L) 1r ,α(‖b‖f ) ( y) >t}| 1q,where‖b‖=∏mj=1‖bj‖Oscexp Lrj,Φ( t) =t( 1 + log+t) 1r,1r =1r1+ ...+ 1rm,ML(…  相似文献   

11.
In this paper, we obtain asymptotic bounds, under appropriate conditions, of solutions of third order difference equations of the form
$ \Delta (p_{n - 1} \Delta (r_{n - 1} \Delta y_{n - 1} )) = f(n,y_n \Delta y_{n - 1} ) + g(n,y_n \Delta y_{n - 1} ), $ \Delta (p_{n - 1} \Delta (r_{n - 1} \Delta y_{n - 1} )) = f(n,y_n \Delta y_{n - 1} ) + g(n,y_n \Delta y_{n - 1} ),   相似文献   

12.
This paper discusses the oscillation of solutions for systems of nonlinear neutral type parabolic partial fuctional differential equations of the form  相似文献   

13.
14.
We obtain sufficient conditions for the Perron stability of the trivial solution of a real difference equation of the form
where and. The resuits obtained are valid for the case where. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 51, No. 12, pp. 1593–1603, December, 1999.  相似文献   

15.
The class of finitely presented groups is an extension of the class of triangle groups studied recently. These groups are finite and their orders depend on the Lucas numbers. In this paper, by considering the three presentations
and
we study Mon(π i ), i=1,2,3, and Sg(π i ), i=2,3, for their finiteness. In this investigation, we find their relationship with Gp(π i ), where Mon(π), Sg(π) and Gp(π) are used for the monoid, the semigroup and the group presented by the presentation π, respectively.  相似文献   

16.
In this paper, sufficient conditions have been obtained for oscillation of all solutions of a class of nonlinear neutral delay difference equations of the form
$ \Delta \left( {r\left( n \right)\Delta \left( {y\left( n \right) + p\left( n \right)y\left( {n - m} \right)} \right)} \right) + q\left( n \right)G\left( {y\left( {n - k} \right)} \right) = 0 $ \Delta \left( {r\left( n \right)\Delta \left( {y\left( n \right) + p\left( n \right)y\left( {n - m} \right)} \right)} \right) + q\left( n \right)G\left( {y\left( {n - k} \right)} \right) = 0   相似文献   

17.
In this paper we consider the following two-phase obstacle-problem-like equation in the unit half-ball
$\Delta u = \lambda_{+} \chi_{\{u >0 \}}-\lambda_{-} \chi_{\{u <0 \}},\quad \lambda_\pm >0 .$\Delta u = \lambda_{+} \chi_{\{u >0 \}}-\lambda_{-} \chi_{\{u <0 \}},\quad \lambda_\pm >0 .  相似文献   

18.
LetL be a self-adjoint linear operator andN be the gradient of a functional ϕ, which is almost quadratic. We first give a theorem on the surjectivity of the operatorL+N, then apply the result to semilinear elliptic systems:
  相似文献   

19.
In this paper, the existence “in the large” of time-periodic classical solutions (with period T) is proved for the following two dissipative ε-approximations for the Navier-Stokes equations modified in the sense of O. A. Ladyzhenskaya:
(1)
(1)
and the following two dissipative ε-approximations for the equations of motion of the Kelvin-Voight fluids: satisfying the free surface conditions on the boundary ϖΩ of a domain Ω⊂R3:
. The free term f(x, t) in systems (1)–(4) is assumed to be t-periodic with period T. It is shown that as ε→0, the classical t-periodic solutions (with period T) of Eqs. (1)–(4) satisfying the free surface conditions (5) converge to the classicat t-periodic solutions (with period T) of the Navier-Stokes equations modified in the sense of O. A. Ladyzhenskaya and to the equations of motion of the Kelvin-Voight fruids, respectively, satisfying the boundary condition (5). Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 210, 1994, pp. 109–124. Translated by N. S. Zabavnikova.  相似文献   

20.
Some new criteria for the oscillation of difference equations of the form
and
are established.  相似文献   

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