A LOWER BOUND FOR FIRST EIGENVALUE WITH MIXED BOUNDARY CONDITIOIN

§1　IntroductionLet( Mn,ds2 ) be an n-dimensional connected compact Riemannian manifold with orwithout boundary.In local coordinates( x1 ,...,xn) ,the Riemannian metric is given byds2 =∑gijdxidxjand the Laplace-Beltrami operatorΔacting on function is defined asΔ=g- 1 / 2 ∑ xi g1 / 2 gij xj ,where( gij) =( gij) - 1 and g=det( gij) .Set N = M.Let f be a smooth function on M,we consider the following eigenvalueproblems.( A) ( i) When N= ,i.e.,M is closed,we consider the free membrane…     

BOUNDARY ELEMENT APPROXIMATION OF STEKLOV EIGENVALUE PROBLEM FOR HELMHOLTZ EQUATION

1.IntroductionWeconsiderthefollowingStekloveigenvalueproblem:FindnonzerouandnumberA,suchthat--An u=0,infi,on,on=An,onr,(1.1)wherefiCRZisaboundeddomainwithsufficientsmoothboundaryr,4istheonoutwardllormalderivativeonr.CourantandHilb..tll]studiedthefollowingeigenvalueproblem:onac=0,infi,--~An,onr,(1.2)OnwhichwasreducedtotheeigenvalueproblemofanintegralequationbyusingtheGreen'sfunctionofAn=0withNuemannboundarycondition.FromFredholmtheorem,weknowthat(1)theproblem(1.2)hasinfinitenumberofeigenv…     

ON THE TRANSPORT EQUATION WITH INTEGRAL BOUNDARY CONDITIONS AND ITS CONSERVAIVE LAW

The well-posedness for the time-dependent neutron transport equationwith integral boundary conditions is established in L~1 space. Some spectral propertiesof the transport operator are discussed, the dominant eigenvalue is proved existing,and furthermore, the conservative law of migrating particle numbers is established.     

有界域上三维非等熵半导体方程解的渐近性(英文)

本文讨论了一类三维非等熵半导体方程. 利用能量估计法, 证明了热平衡稳态解的存在唯一性.然后, 得到了Cauchy-Neumann问题光滑解的整体存在性以及当t→ +∞这种光滑解以指数速度收敛到稳定解, 改进了文献[12]的结果.     

有界多连通域的Schatten类Toeplitz算子

本文讨论了多连通域的Bergman空间上的以正测度为符号的Toeplitz算子.用符号测度的Berezin 变换和平均函数刻画了Toeplitz算子为Schatten类算子的充要条件.     

THE BOUNDARY INTEGRAL METHOD FOR THE HELMHOLTZ EQUATION WITH CRACKS INSIDE A BOUNDED DOMAIN

We consider a kind of scattering problem by a crack Γ that is buried in a bounded domain D,and we put a point source inside the domain D.This leads to a mixed boundary value problem to the Helmholtz equation in the domain D with a crack Γ.Both sides of the crack Γ are given Dirichlet-impedance boundary conditions,and different boundary condition(Dirichlet,Neumann or Impedance boundary condition) is set on the boundary of D.Applying potential theory,the problem can be reformulated as a system of boundary integral equations.We establish the existence and uniqueness of the solution to the system by using the Fredholm theory.     

关于有界全纯函数在边界附近的某些性质

<正> 在[1]中 H.G.Eggleston 曾经证明了如下一个很有用的定理.设 f(z)是区域 D 内的有界全纯函数并 z_0为 D 的某一界点,z_0可为∞,但 D 至少人含有一有限还点为其界点.让 L 是一弧而以 z_0为其一端点且其他各点全属 D 内.若     

一个供应链系统可靠性模型时间依赖解的渐近行为

本文研究一个供应链系统可靠性模型的时间依赖解.利用C0-半群理论研究该模型相应算子的谱的特征,获得了该系统模型时间依赖解的渐近行为,推广了文献[8]中的结果.     

ESTIMATES ON EIGENVALUES FOR THE BIHARMONIC OPERATOR ON A BOUNDED DOMAIN IN H~n(-1)

In this paper, we consider eigenvalues of the Dirichlet biharmonic operator on a bounded domain in a hyperbolic space. We obtain universal bounds on the (k + 1)th eigenvalue in terms of the first kth eigenvalues independent of the domains.     

EIGENVALUES OF STURM-LIOUVILLE OPERATOR WITH GENERAL BOUNDARY CONDITIONS

We study the asymptotic behavior for the eigenvalues of Sturm-Liouville operators with smooth potential.The precise asymptotic expressions for the eigenvalues of the operators with general boundary conditions are given.     

一类非线性映象的Yosida近似与渐近性质

设Ａ为自反Ｂａｎａｃｈ空间Ｘ上的任意极大单调映象，Ｊ为Ｘ到Ｘ的正规对偶映象，本文对复合映象Ｂ＝ＪＡ＾－ＩＪ定义其Ｙｏｓｉｄａ近似和预解式算子，并证明它们的若干渐近性质，作为应用，指出对Ｆ．Ｅ．Ｂｒｏｗｄｅｒ单调算子构造可解性问题的化简及对Ｒ．Ｔ．Ｒｏｃｋａｆｅｌｌａｒ，Ｇ．Ｋａｓｓａｙ的邻近点算法收敛性结果的推广。     

CONDITION NUMBERS OF A MULTIPLE EIGENVALUE

This paper studies the symmetric eigenvalue problem Ax = λBx, where A,B are real symmetric matrices, and B is positive definite. Condition numbers of a multiple eigenvalue are derived from the first order perturbation expansions.     

A CLASS OF POWER BOUNDED GENERALIZED SHIFT

1 Main Results and ProofsClassical shift operator S on 11 is defined by S(co, clt' .) = (0, col c19' .). For any yector(al, a2,' .) E l., define the operator (al, a2,' .) @ ek: 11 - 11 byNow,we consider the following generalized shift operator:Definition 1 T is said to be power bounded if slip. liT"II < co.Definition 2 Let f(z) = Bo Blz ' be operator valued analytic function in theunit disk D,where Ba: IT ~ l? are bounded linear operator,llBk 11 = sup,Sjsm(Z:=, la::) 1),Ba =…     

Finsler流形上的Laplace比较定理和有界估计(英文)

本文研究了Finsler流形上的距离函数的Laplacian.利用指标引理和文献[4]中主要方法,获得了Ricci曲率有函数下界的Laplacian比较定理,改进了文献[6]和文献[7]的相关结果.     

具有内部构造安全保障体系的冗余机器系统的特征值的问题

对具有内部构造安全保障体系的冗余机器系统中的特征值的存在性进行了分析求解,给出了实例,并对该系统的特征值进行了一个特征值对应一个特征向量的求征.     

两部件并联维修系统算子的性质

研究了两部件并联维修系统算子的性质,通过选取空间和定义算子将模型方程转化成了抽象柯西问题,证明了系统算子是定义域稠的预解正算子,0是系统算子的几何重数为1的本征值.讨论了系统算子的共轭算子及其定义域,证明了0是共轭算子的代数重数为1的特征值.     

全连续算子的固有值,固有元的全局特征和应用

仅分别在‖Ａｘ‖‖ｘ‖→＋∞（‖ｘ‖→＋∞）和‖Ａｘ‖‖ｘ‖→＋∞（‖ｘ‖→０）之下，研究全连续算子的固有值、固有元的某种全局特征，并应用到Ｈａｍｍｅｒｓｔｅｉｎ算子的研究上，得到了新的结果．     

关于C~n中具有逐块光滑边界的有界域上C-L公式与C-F公式的拓广式

得到了Ｃｎ空间中具有逐块Ｃ（１）光滑边界的有界域上光滑函数的一个抽象的积分公式．这个公式的特点是积分核中含有一系列向量函数Ｗ（０,Ｋ）（,ｚ）,Ｗ（ｉ,ｋ）（,ｚ）及一系列独立的实参数由这个公式,适当选取其中的参数和向量函数Ｗ,就可得到具有这种逐块Ｃ（１）光滑边界的有界域上光滑函数的Ｃａｕｃｈｙ－Ｌｅｒａｙ公式和全纯函数的Ｃａｕｃｈｙ－Ｆａｎｔａｐｐｉｅ公式以及其它一些新的公式．     

THE WAVE EQUATION APPROACH TO THE TWO-DIMENSIONAL INVERSE PROBLEM FOR A GENERAL BOUNDED DOMAIN WITH PIECEWISE SMOOTH MIXED BOUNDARY CONDITIONS

1 IntroductionLet fl be a simply connected bounded domain in R2 with a smooth boundary 0fl. Considerthe two-dimensional Robin problemwhere k denotes differentiation aIong the inward pointing normal to 0n and 7 is a positiv('constan. Denote its eigenvalues, counted according to multiplicity, byZayed alld Hassall[15'16] l1ave discussed the probleln (1. 1)-(1.2) fOr small / large impedance7 and have determned some geometric quantities of the don1ain n, using tl1e asymptotic ex-pansion of tlie s…     

S~(n+1)(1)内凸超曲面为边界的区域的第一特征值估计

Ｍ是Ｓｎ＋１(１)内紧致嵌入凸超曲面．Ｍ分Ｓｎ＋１(１)为两个连通区域Ω１和Ω２．Ω１＝Ｍ和Ω１是凸的．本文估计了Ω１的Ｌａｐｌａｃｅ算子的第一特征值的下界．