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51.
Minoru Murata 《Journal of Functional Analysis》2002,194(1):53-141
We consider positive solutions of elliptic partial differential equations on non-compact domains of Riemannian manifolds. We explicitly determine Martin boundaries and Martin kernels for a class of elliptic equations in skew product form by exploiting and developing perturbation theory for elliptic equations and short/long-time estimates for fundamental solutions of parabolic equations. 相似文献
52.
四阶半线性椭圆型积分微分方程的奇摄动 总被引:5,自引:1,他引:4
本文研究了一个四阶椭圆型积分微分方程的奇摄动问题。证明了相应的比较定理并得到了解的一致有效的渐近展开式。 相似文献
53.
该文用Shauder不动点定理及微分不等式理论研究了一类非线性四阶常微分方程三点边值问题的存在性,并利用边界层校正法获得解及其二阶导数的高阶渐进展开式. 相似文献
54.
Fabio Fantozzi Sauro Filippeschi Enrico Maria Latrofa 《Superlattices and Microstructures》2004,35(3-6):339
Upward and downward two-phase heat and mass transfer has been considered in the present paper. The heat and mass transfer with the condenser located below the evaporator has been obtained by inserting an accumulator tank in the liquid line of a loop thermosyphon and enforcing a pressure pulsation. In previous papers these heat transfer devices have been called pulsated two phase thermosyphons (PTPT). A mini PTPT has been experimentally investigated. It has shown a stable periodic heat transfer regime weakly influenced by the position of the condenser with respect to the evaporator. In contrast a classical loop mini thermosyphon (diameter of connecting pipes 4 mm) did not achieve a stable functioning for the investigated level differences between evaporator and condenser lower than 0.37 m. The present study shows that the functioning of a PTPT device does not directly depend on the level difference or the presence of noncondensable gas. In order to obtain a natural circulation in mini or micro loops, a periodically operating heat transfer regime should therefore be considered. 相似文献
55.
THE ASYMPTOTIC SOLUTION FOR A CLASS OF SINGULARLY PERTURBED PROBLEM FOR SEMILINEAR SINGULAR EQUATION
The singularly perturbed boundary value problem for a class of semilinearsingular equation is considered. Using a simple and special method the asym-ptotic behavior of solution is studied. 相似文献
56.
Rafael Ortega 《Journal of Dynamics and Differential Equations》1992,4(4):651-665
This paper gives sufficient conditions for the existence of periodic solutions of twist type of a time-dependent differential equation of the second order. The concept of periodic solution of twist type is defined in terms of the corresponding Birkhoff normal form and, in particular, implies that the solution is Lyapunov stable. Some applications to nonlocal problems are given. 相似文献
57.
58.
Hubert Kalf 《Journal of Differential Equations》2004,205(2):408-423
We show that the point spectrum of the standard Coulomb-Dirac operator H0 is the limit of the point spectrum of the Dirac operator with anomalous magnetic moment Ha as the anomaly parameter tends to 0. For negative angular momentum quantum number κ, this holds for all Coulomb coupling constants c for which H0 has a distinguished self-adjoint realisation. For positive κ, however, there are some exceptional values for c, and in general an index shift between the eigenvalues of H0 and the limits of eigenvalues of Ha appears, accompanied with additional oscillations of the eigenfunctions of Ha very close to the origin. 相似文献
59.
TorstenLinB 《计算数学(英文版)》2003,21(4):401-410
We consider a singularly perturbed semilinear convection-diffusion problem with a boundary layer of attractive turning-point type. It is shown that its solution can be decomposed into a regular solution component and a layer component. This decomposi-tion is used to analyse the convergence of an upwinded finite difference scheme on Shishkin meshes. 相似文献
60.
In this paper, existence criteria are established for the existence of periodic solutions of a second order sublinear differential equation with delay and forcing function. Our method is based on careful a priori estimation and continuation theorems, and our sublinear condition is an improvement of the boundedness condition in some recent results. 相似文献