表有限域上矩阵为两个可逆矩阵的平方和

本文将有限域Ｆｑ（ｃｈａｒ Ｆｑ≠２）上的Ｄｉｃｋｓｏｎ方程：ｘ＾２＋ｙ＾２＝ａ（ａ≠０）当│Ｆｑ│≥７时在Ｆｑ＾－中有解的经典结果推广到ｎ阶方阵上，证明了只要Ｆ≠Ｆ２，除奇数阶纯量阵外每一ｎ阶方阵可表为两个可逆阵的平方和。     

An application of the capacitance matrix method to accommodate masked land areas and island circulations in a primitive equation ocean model

The capacitance matrix method has been implemented in a primitive equation ocean model to accommodate islands and portions of irregular coastal boundaries that cannot be treated adequately by boundary-fitted orthogonal curvilinear co-ordinates. The algorithm preserves the ability to solve the streamfunction equation using fast and accurate elliptic solvers that require a rectangular computational domain. By superposition of a set of island Green functions, the solution is adjusted to ensure continuity of pressure around each island. The implementation is tested by comparison with an analytic solution for wind-driven flow in a closed basin similar to the southwest Pacific Ocean.     

关于隐式LU分解算法分解算法求矩阵主子阵逆的注记（英）

ＡＲｅｍａｒｋｏｎｔｈｅＩｎｖｅｒｓｅｏｆＰｒｉｎｃｉｐａｌＭａｔｒｉｃｅｓｂｙＩｍｐｌｉｃｉｔＬＵＦａｃｔｏｒｉｚａｔｉｏｎＨｕａｎｇＫａｉｂｉｎＷｕＨｅｂｉｎ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＮａｎｊｉｎｇＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｊｉ...     

A globally well-posed finite element algorithm for aerodynamics applications

A finite element CFD algorithm is developed for Euler and Navier-Stokes aerodynamic applications. For the linear basis, the resultant approximation is at least second-order-accurate in time and space for synergistic use of three procedures: (1) a Taylor weak statement, which provides for derivation of companion conservation law systems with embedded dispersion-error control mechanisms; (2) a stiffly stable second-order-accurate implicit Rosenbrock-Runge-Kutta temporal algorithm; and (3) a matrix tensor product factorization that permits efficient numerical linear algebra handling of the terminal large-matrix statement. Thorough analyses are presented regarding well-posed boundary conditions for inviscid and viscous flow specifications. Numerical solutions are generated and compared for critical evaluation of quasi-one- and two-dimensional Euler and Navier-Stokes benchmark test problems. Of critical importance, essentially non-oscillatory solutions are uniformly attained for a range of supercritical flow situations with shocks.     

N维最弱受约束电子势模型的精确解

精确地求解了N维最弱受约束电子势模型束缚态的Schrodinger方程,得到了其能级和相对应的归一化径向波函数.在此基础上,运用广义拉盖尔多项式的级数展开得到了N维最弱受约束电子势模型径向矩阵元的通项表达式.     

The matrix equation AXB+CYD=Eover a simple artinian ring

This paper discussed the matrix equation AXB+CYD=Eover a simple Artinian ring, obtains several necessary and sufficient conditions for existence of a solution, gives the representation of solution by g-inverses, and extends a theorem of W.E. Roth's simple Artinian rings.     

退化时滞差分系统的通解

讨论具有时滞的退化差分系统，给出其初始函数的相容性条件，并给出其通解，最后举例说明之．     

由路段交通量推算OD矩阵的一种有效方法及其应用

针对现有OD矩阵估计方法的不足，本讨论了一种新的有效的估计方法，它包括一个路段流量的预处理过程，以消除路段观测流量的不相容，然后经过流量加载和卸载两个逆过程，进行反复迭代，最终得到再现路段交通量的OD矩阵，中例证了该方法的有效性。     

Alternating-Sign Matrices and Domino Tilings (Part II)

We continue the study of the family of planar regions dubbed Aztec diamonds in our earlier article and study the ways in which these regions can be tiled by dominoes. Two more proofs of the main formula are given. The first uses the representation theory of GL(n). The second is more combinatorial and produces a generating function that gives not only the number of domino tilings of the Aztec diamond of order n but also information about the orientation of the dominoes (vertical versus horizontal) and the accessibility of one tiling from another by means of local modifications. Lastly, we explore a connection between the combinatorial objects studied in this paper and the square-ice model studied by Lieb.     

恰有t行含对称正元的布尔方阵的幂敛指数的估值

设Ｄｎ，２（ｔ）为恰有ｔ行含对称正元的ｎ阶布尔方阵的集合，２≤ｔ≤ｎ。本文证明了，对于任给Ａ∈Ｄｎ，２（ｔ），幂敛指数ｋ（Ａ）≤∫（ｎ－ｔ－１）＾２＋１，３ｎ－ｔ－２，当ｔ≤ｎ－［３＋√８ｎ－７／２］当ｔ〉ｎ－［３＋√８ｎ－７／２］，这里［ｘ］表示不小于ｘ的最小整数。同时，我们还证明了这个界是可以达到的，并且对Ｄｎ，２（ｔ）的极矩阵集合作了部分刻划。