三维空间中的有界凸域和拟球

本文证明了三维空间中的有界凸域是拟球，从而也说明了拟共形映照中的黎曼定理在三维空间中的有界凸域上是成立的     

强拟凸域到单位球的嵌入

在本文中,我们证明了如下结果:C~n 中具 c~2 边界的有界强拟凸域的有限交能嵌入为某有限维单位球的闭复子流形,更进一步,Stein 流形中具 c~2 边界的相对紧强拟凸域的有限交能嵌入为某单位球的闭复子流形.     

外部边界球可达域上拟共形映射的Lipschitz连续性

定义了外部边界球可达域,利用曲线族的模获得如下结果:设D是R~n中的有界拟凸域,f:D→B~n是K-拟共形映射,若D是外部边界球可达域,则f∈Lip_α(D),其中α=K~(1/(1-n)).     

内部边界球可达域和拟共形映射的Hlder连续性

定义了内部边界球可达域,利用曲线族的模证明了D是R~n中的有界Jordan域,f:B~n→D是K-拟共形映射,若D是内部边界球可达域,则f∈H_(1/K)(B~n).     

内球性质和拟共形映射

研究了一类具有内球性质区域的几何与分析性质,证明了f(∞)=∞的同胚f:-Rn→-Rn是拟共形映射当且仅当f保持区域的内球性质不变,并获得了该类区域若干有趣的几何性质.     

内部边界球可达域和拟共形映射的H(o)lder连续性

定义了内部边界球可达域,利用曲线族的模证明了D是Rn中的有界Jordan域,f:Bn→D是K-拟共形映射,若D是内部边界球可达域,则f∈H1/K(Bn).     

误差为球对称分布的非线性回归

本文讨论了误差为球对称分布的非线性回归模型,给出了最小二乘估计量(LSE)的随机展开式、偏差、方差和偏度,残差和拟合误差的偏差、方差,并讨论其近似置信域。     

拟调和球的不存在性

证明了当N的万有覆盖上存在一个多项式增长的非负严格凸函数时,不存在从R~3到N的非平凡拟调和球.于是在dim M=3时推广了Eells-Sampson的定理.     

拟调和球的不存在性

证明了当N的万有覆盖上存在一个多项式增长的非负严格凸函数时,不存在从R3到N的非平凡拟调和球.于是在dim M=3时推广了Fells-Sampson的定理.     

拟极值距离域和拟共形映照的扩张

本文研究了空间R_n中的拟极值距离城,找到了一个可以拟共等价于球而不是拟极值距离域的例子,给出了拟极值距离域的一个等价定义,证明了一个Jordan的拟极值距离域的外部是拟极值距离城的充分条件为它是拟共形反射域。最后我们还建立了一个平面拟共形映照的扩张性质。     

Some problems of conformal mappings of spherical domains

In this study the problem of finding the conformal mapping from a sphere onto a plane with a given scale function independent of longitude is solved for an arbitrary spherical domain. The obtained results are compared with the well-known projections used in cartography and geophysical fluid dynamics. The problem of minimization of the distortion under conformal mappings is solved for domains in the form of the spherical disk. The distortions of some extensively used conformal mappings are compared with the distortions of orthogonal mappings.     

Some problems of conformal mappings of spherical domains

In this study the problem of finding the conformal mapping from a sphere onto a plane with a given scale function independent of longitude is solved for an arbitrary spherical domain. The obtained results are compared with the well-known projections used in cartography and geophysical fluid dynamics. The problem of minimization of the distortion under conformal mappings is solved for domains in the form of the spherical disk. The distortions of some extensively used conformal mappings are compared with the distortions of orthogonal mappings.     

The local homeomorphism property of spatial quasiregular mappings with distortion close to one

We give a quantitative proof for a theorem of Martio, Rickman and V?is?l? [MRV] on the rigidity of the local homeomorphism property of spatial quasiregular mappings with distortion close to one. The proof is based on a distortion theory established by using two main tools. First, we use a conformal invariant between sphere families and components of their preimages under quasiregular mappings. Secondly, we use Hall’s quantitative isoperimetric inequality result [H] to relate two different types of distortion. Received: April 2004 Revision: October 2004 Accepted: December 2004     

关于具有可积伸张同胚的紧性

具有可积球伸张的同胚的偏差定理、等度连续性和紧性被得到．     

Uniqueness for the homogeneous Dirichlet Willmore boundary value problem

We give a sufficient condition for curves on a plane or on a sphere such that if these give the boundary of a Willmore surface touching tangentially along the boundary the plane or the sphere respectively, the surface is necessarily a piece of the plane or a piece of the sphere. The condition we require is that the curves bound a strictly star-shaped domain with respect to the Euclidean geometry in the plane and with respect to the spherical geometry in the sphere, respectively.     

复双球垒域上奇异积分的估计

文[1]中研究了复超球上的奇异积分．本文利用复双球面上的立体角系数的方法，把[1]中复超球上的奇异积分推广到复双球垒域上，得到复双球垒域上奇异积分的一些估计．     

Regularity of the inverse of a homeomorphism with finite inner distortion

Let f:Ω→ f(Ω) R~n be a W~(1,1)-homeomorphism with L~1-integrable inner distortion.We show that finiteness of min{lip_f(x),k_f/(x)},for every x ∈Ω\E,implies that f~(-1) ∈ W~(1,n)and has finite distortion,provided that the exceptional set E has cr-finite H~1-measure.Moreover,/ has finite distortion,differentiable a.e.and the Jacobian J_f 0 a.e.     

Robin functions and distortion theorems for regular mappings

Capacities of generalized condensers are applied to prove a two‐point distortion theorem for conformal mappings. The result is expressed in terms of the Robin function and the Robin capacity with respect to the domain of definition of the mapping and subsets of the boundary of this domain. The behavior of Robin function under multivalent functions is studied. Some corollaries and examples of applications to distortion theorems for regular functions are given (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A New Non-Overlapping Domain Decomposition Method for a 3D Laplace Exterior Problem

We propose a method for solving three-dimensional boundary value problems for Laplace’s equation in an unbounded domain. It is based on non-overlapping decomposition of the exterior domain into two subdomains so that the initial problem is reduced to two subproblems, namely, exterior and interior boundary value problems on a sphere. To solve the exterior boundary value problem, we propose a singularity isolation method. To match the solutions on the interface between the subdomains (the sphere), we introduce a special operator equation approximated by a system of linear algebraic equations. This system is solved by iterative methods in Krylov subspaces. The performance of the method is illustrated by solving model problems.     

常曲率的多複變數域

<正> 以(z)=(z~1,…,z~n)代表n個複變數,其中z~k=x~k+iy~k,而x~k,y~k,是實數。代表此2n維空間的一個囿域,命表一函數系,其中每一函數f(z)都有以下的性質:(i)f(z)在內是解析的,(ii)積分