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991.
Lian-Xi Ku 《Southeast Asian Bulletin of Mathematics》2000,24(3):375-382
In this note, we prove that, for Robins boundary value problem, a unique solution exists if fx(t, x, x), fx(t, x, x), (t), and (t) are continuous, and fx -(t), fx -(t), 4(t) 2 + 2(t) ++ 2(t), and 4(t) 2 + 2(t) + 2(t).AMS Subject Classification (2000) 34B15 相似文献
992.
M. M. Cavalcanti V. N. Domingos Cavalcanti J. A. Soriano L. A. Medeiros 《Southeast Asian Bulletin of Mathematics》2000,24(2):183-199
In this paper, we study a hyperbolic model based on the equation
with nonlinear boundary conditions given by
.We prove the existence and the uniqueness of global solutions. Also, we obtain the uniform decay of the energy without control of its derivative sign.AMS Subject Classification (2000), 35L05, 35L70, 35B40 相似文献
993.
We consider a one-dimensional incompressible flow through a porous medium undergoing deformations such that the porosity and the hydraulic conductivity can be considered to be functions of the flux intensity. The medium is initially dry and we neglect capillarity, so that a sharp wetting front proceeds into the medium. We consider the open problem of the continuation of the solution possibly in the case of onset of singularities, which can be interpreted as a local collapse of the medium. In particular we analyze the case in which the boundary pressure has a piecewise constant derivative. 相似文献
994.
51. IntroductionLet fi C Re (n = 1,2) be a bounded smooth domain. Consider the following nonhomogeneous initial-boundary value problem for the unsaturated Landau-Lifshitz systems offerromagnetic spin chain with Gilbert damping constant afl > 0,where adZ is the exchange constallt, u = (u', u', u'), "o(x) is smooth and satisfies the unsaturated condition, i.e., Ilo(~)I gi constant, and in IVuol' < co, "o(x)IOn = op(x). DenoteW(x) = luo(x)I. We assume 0 < m = mane < M ~ mpxW. Throughout t… 相似文献
995.
The evolution Boussinesq equations describe the evolution of the temperature and velocity fields of viscous incompressible Newtonian fluids. Very often, they are a reasonable model to render relevant phenomena of flows in which the thermal effects play an essential role. In the paper we prescribe non-Dirichlet boundary conditions on a part of the boundary and prove the existence and uniqueness of solutions to the Boussinesq equations on a (short) time interval. The length of the time interval depends only on certain norms of the given data. In the proof we use a fixed point theorem method in Sobolev spaces with non-integer order derivatives. The proof is performed for Lipschitz domains and a wide class of data. 相似文献
996.
Petr Knobloch 《Applications of Mathematics》2000,45(2):99-129
We investigate a finite element discretization of the Stokes equations with nonstandard boundary conditions, defined in a bounded three-dimensional domain with a curved, piecewise smooth boundary. For tetrahedral triangulations of this domain we prove, under general assumptions on the discrete problem and without any additional regularity assumptions on the weak solution, that the discrete solutions converge to the weak solution. Examples of appropriate finite element spaces are given. 相似文献
997.
C. Foin A. Gizon D. Barnéoud J. Genevey J. Gizon D. Santos F. Farget P. Paris C. F. Liang D. Bucurescu A. Płochocki 《The European Physical Journal A - Hadrons and Nuclei》2000,8(4):451-454
The decay of the T
1/2 = 420 ns isomer in 151Er has been reinvestigated. The multipolarities of the decaying transitions have been established by measuring the electron
conversion coefficients. An I
π
= 67/2− assignment is proposed for this isomer with a π[h
112/4
d
32/1
d
52/−1]⊗ν[f
7/2
h
9/2
h
112/−1] configuration. 相似文献
998.
根据Shafranov电流密度矩理论,给出了用可移动电流丝方法重建HL-2A装置等离子体边界的具体计算方法,研究了用可移动电流丝方法(VCF法)重建边界的可行性.VCF法与固定电流丝方法(FCF法)和有限电流元法(FCE法)相比,最大的优点就是用1—3个可移动电流丝就可以准确地重建位置和小半径快速变化的等离子体位形,这正好弥补了FCF法的不足.将可移动电流丝方法和FCF法相结合,可以实现全程等离子体放电的边界实时显示和等离子体的位形控制.
关键词:
可移动电流丝方法
边界识别 相似文献
999.
1000.
In order to understand the rise of runaway solutions in the radiation reaction problem a mechanical model is used. An alternative
demonstration of Daboul’s theorem, through Hurwitz’s criterion, is given. The origin of runaway solutions in electrodynamics
is discussed. They arise when the particle has a negative mechanical mass or when approximations are used in the equation
of motion. In the 1-dimensional mechanical model an exact and linear equation of motion for the particle is obtained, the
corresponding exact solution is again runaway when the mechanical mass is negative. The exact solution is not runaway when
the mechanical mass is positive. However, the use of approximations leads to an equation of motion which has runaway solutions.
It is exhibited that the use of approximations in the 3-dimensional mechanical model is completely necessary because the general
equation of motion for the particle is non-linear. The analysis of this case proceeds in a very similar way to the one carried
out in electrodynamics. This means that the number of dimensions also plays an important role in the analysis. 相似文献