Dam-Break Flows Over a Bottom Step

A single-layer shallow-water model is used to study the solvability of the problem of flows generated by dam break over a bed level discontinuity in the form of a step onto which water flows. Solutions in which the total flow energy is conserved on the step and solutions in which the energy is lost on the step are considered.     

p-致凸Banach空间中渐近半压缩映象迭代过程的强收敛性

研究p-致凸Banach空间中渐近半压缩映象的修正的Mann迭代过程和修正的Ishikawa迭代过程的强收敛性．本文始终假设X是P-致凸Banach空间．最近，r-渐近半压缩映象的概念被引入，并给出了X中该映象（此时，r=P）的修正的Mann迭代过程和修正的Ishikawa迭代过程的强收敛性定理，文章所得结果改进、推广和统一了近期相关结果．     

Break conductance of Al nanocontacts

We measured a break conductance, the last conductance of a contact before its complete break, for Al nanocontacts of 0–200G₀ (G₀≡2e²/h is the quantum unit of conductance) in ultrahigh vacuum at room temperature. We found that the distribution of the break conductance shows a broad single peak, the position of which shifts with the contact current. From the observed current dependence of the break conductance peak, it is suggested that Al nanocontacts break up most likely when the contact current density reaches a critical value 5×10¹⁰ A/cm².     

分组数据的线性回归模型及其在医学上的应用

本文给出分组数据的线性回归模型及其检验，并将其应用于医学研究。     

A necessary extremality condition for a set-valued stochastic control problem

For a controlled stochastic dynamic system with set-valued drift coefficient and a terminal cost functional we derive a necessary extremality condition in form of a minimum principle.     

Growth theorem of convex mappings on bounded convex circular domains

The growth theorem and the 1/2-covering theorem are obtained for the class of normalized biholomorphic convex mappings on bounded convex circular domains, which extend the corresponding results of Sufridge, Thomas, Liu, Gong, Yu, and Wang. The approach is new, which does not appeal to the automorphisms of the domains; and the domains discussed are rather general on which convex mappings can be studied, since the domain may not have a convex mapping if it is not convex. Project supported by the National Natural Science Foundation of China and the State Education Commission Doctoral Foundation.     

双特征的Beltrami方程和拟正则映射

设Ω为Ｒｎ上的一个区域，ｎ２，对于具有双特征矩阵Ｇ（ｘ），Ｈ（ｘ）∈Ｃｋ，α（Ω，Ｒｎ），ｋ１，０＜α＜１的Ｂｅｌｔｒａｍｉ方程（１．４），建立了在Ｓｏｂｏｌｅｖ空间Ｗ１，ｎｌｏｃ（Ω，Ｒｎ）上广义解的正则性：ｆ（ｘ）∈Ｃｋ＋１，δｌｏｃ（Ω），对某一δ：０＜δ＜１．     

On the stability of closed-convex-valued mappings and the associated boundaries

This paper deals with the stability properties of those set-valued mappings from locally metrizable spaces to Euclidean spaces for which the images are the convex hull of their boundaries (i.e., they are closed convex sets not containing a halfspace). Examples of this class of mappings are the feasible set and the optimal set of convex optimization problems, and the solution set of convex systems, when the data are subject to perturbations. More in detail, we associate with the given set-valued mapping its corresponding boundary mapping and we analyze the transmission of the stability properties (lower and upper semicontinuity, continuity and closedness) from the given mapping to its boundary and vice versa.     

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．     

On the absence of cycles for unimodal mappings of the square

Unimodal 2-endomorphisms of a special kind of the unit square are considered. Conditions for the absence of periodic points are presented. Translated fromMatematicheskie Zametki, Vol. 63, No. 3, pp. 370–378, March, 1998.