关于幂等元之差的可逆性

本文研究在一个有单位元的环中两个幂等元之差的可逆性问题,利用幂等元的性质,得到了两个幂等元之差可逆的几个充分必要条件,并给出了在矩阵环中的几个应用.     

一类矩阵的AOR迭代收敛性分析及其与SOR迭代的比较

1 引言 许多实际问题最后常归结为解一个或一些矩阵的线性代数方程组Ax=b （1.1）这里讨论A为（1，1）相容次序矩阵的情形。     

ON THE IRREDUCIBILITY OF THE DETERMINANT OF THE MATRIX OF MOVING PLANES

ABSTRACT

We show that, for generic bihomogeneous polynomials, the determinant of the matrix of moving planes is irreducible.     

ON THE PROBLEMS OF THE INFINITESIMAL DEFORMATION OF THE SURFACES OF REVOLUTION WITH MIXED CURVATURE

In this paper the problem of the infinitesimal deformation of the surfaces of revolution with mixed Ganss curvature is studied. In connection with this problem a differential equation of mixed type, which belongs to the second degenerate type, in the form , \[k(\rho ){w_{\rho \rho }} + {w_{\theta \theta }} + \rho {w_\rho } = 0({\rho _1} < \rho < {\rho _2},0 \leqslant \theta \leqslant 2\pi )\] is obtained, where w is the component of the displacement vector of the infinitesimal deformation in the direction of the rotation axis, and\[k(\rho ) = \rho {z^'}(\rho )/{z^{'}}(\rho ),z(\rho )\] being the meridian curve of the surface of revolution. Suppose a surface of revolution S has two holes \[{L_1}(\rho = {\rho _1})\] and \[{L_2}(\rho = {\rho _2})\], then the meridian of the surface satisfies the condition \[{z^'}(\rho ) = 0\] on \[\rho = {\rho _0}({\rho _1} < {\rho _0} < {\rho _2})\]. If the Gauss curvature K of the surface is a strictly monotone increasing function of \[\rho \], \[{K^'}(\rho ) > 0,{\rho _1} < \rho < {\rho _2}\],then the surface S does not permit of the non-trivial sliding on the plane containing the boundary L2 of the surface. The rigidity of the surface is proved by the energy integral method. Moreover, the uniqueness of the Tricomi problem, the generalized Tricomi problem, the degenerate Tricomi problem and the Frankl's problem for a piece of surface with mixed curvature are studied.     

THE UNIQUENESS OF THE DECOMPOSITION OF QUADRATIC LIE ALGEBRAS

In this paper, we consider the decomposition of a quadratic Lie algebra and the main result is that the decomposition of a quadratic Lie algebra into irreducible nondegenerate ideals is unique up to an isometry (Theorem 3.1). As a corollary, we obtain the uniqueness of the decomposition of an arbitrary Lie algebra into indecomposable ideals up to an isomorphism (Corollary 3.5.4).     

样本判决系数的样本特性研究

本文用 bootstrap方法估计 R2和 R2的标准误差并构建置信区间 ,用蒙特卡罗方法说明 bootstrap标准误差的精确程度 ,并说明 R2的 95置信水平的置信区间不包含真实值的某些特殊情况在用 R2时不会发生。     

经济最优化意义下消耗系数的调整

本文基于“正特片矢量法”,提出了一种在经济最优化意义下调整消耗系数的方法.该方法能够综合考虑产综和价格对消耗系数的影响,有着较好的普适性,在计算上简便易行、效果良好,且具有明显的经济意义.     

THE ACTION OF THE LINEAR CHARACTER GROUP ON THE SET OF NON-LINEAR IRREDUCIBLE CHARACTERS THE ACTION OF THE LINEAR CHARACTER GROUP ON THE SET OF NON-LINEAR IRREDUCIBLE CHARACTERS

1. Notations and Basic ResultsLet G be a finite nonabelian group. Then frs(G/G') is an abelian group under themultiplication of characters and acts on the set of non-linear irreducible characters of G viathe multiplication of characters. The purpose of this paper is to investigate this action. Asan application of our theoryl in the end of Section 3 we give the classification of groupshaving exactly three non-linear irreducible caracters.All groups in the paper are finite. For a factor grou…     

第二类Painlevé方程解的亚纯性

Painlevé方程是六类重要的二阶代数微分方程,它们的发展和性质一直受到人们的关注.本文给出第二类Painlevé方程解的亚纯性一个严格的证明.     

置换群直积的张量对称类的秩

假定基环R是特征为零的整环，并且使得它上每个有限生成的投射模是自由模．本文研究有限秩自由R-模的张量积相对于有限个置换群直积而言的张量对称类，给出了张量对称类非平凡的判别准则以及相应张量对称类秩之间的关系式，并将所得结果应用到模情形．     

RESULTS ON SUBGROUPS OF THE GROUP OF HOMEOMORPHISMS OF THE RATIONAL NUMBERS

Abstract

If G is the group of homeomorphisms of the rationals with usual topology and H ? G is such that |G:H| < 2^x0 then there exists a finite, non-empty subset Y of the rational numbers such that G(Y) ? H ? G^{Y} where G(Y) is the group o all homeomorphisms in G fixing a neighbourhood of Y and G^{Y} is the set-wise stabilizer of Y in G.     

凸域内弦的平均长度

本文研究了凸域内弦的平均长度.通过广义支持函数与凸域的弦幂积分,建立了凸域内弦的平均长度的一般公式,并用此公式得出了圆域和矩形域内弦的平均长度.     

C－半群的谱与其生成元谱之间的关系

本文首次给出了Ｃ－半群的预解集和谱的概念，得到了Ｃ－半群的谱与其生成元谱的一系列结果．     

THE UNIQUENESS OF THE SOLUTION OF LIENARD SYSTEM TO THE INITIAL VALUE PROBLEM

1 IntroductionThe Li6nard systemis a very important nonlinear system. Many authors have studied the asymptotic behavior of its solutions. But for this purpose we require first the uniquenessof its solutions to the initial value problem. Most references did not discuss itin detail, they generally assume that F(x) and g(x) are continuous and satisfythe conditions for the uniqueness of the solution. Only few authors gave someconcrete conditions.FOr example Dragilev [1] required that F(x) and g…     

關於區域的映照半徑

<正> §1.設α_1,α_2,…,α_n是z平面上n個相異的點,G_1,G_2,…,G_n是z平面上n個不互相重叠的有限區域,α_k屬於G_k,記G_k對於α_k的映照半徑為     

A MODEL OF THE ENZOOTIOLOGY OF LYME DISEASE IN THE ATLANTIC NORTHEAST OF THE UNITED STATES

A mathematical model is presented for the dynamics of the rate of infection of the Lyme disease vector tick Ixodes dammini (Acari: Ixodidae) by the spirochete Borrelia burgdorferi, in the Atlantic Northeast of the United States. According to this model, moderate reductions in the abundance of white-tailed deer Odocoileus virginianus may either decrease or increase the spirochete infection rate in ticks, provided the deer are not reservoir hosts for Lyme disease. Expressions for the basic reproductive rate of the disease are computed analytically for special cases, and it is shown that as the basic reproductive rate increases, a proportional reduction in the tick population produces a smaller proportional reduction in the infection rate, so that vector control is less effective far above the threshold. The model also shows that control of the mouse reservoir hosts Peromyscus leucopus could reduce the infection rate if the survivorship of juvenile stages of ticks were reduced as a consequence. If the survivorship of juvenile stages does not decline as the rodent population is reduced, then rodent reduction can increase the spirochete infection rate in the ticks.     

并行迭代算法的有效性的度量参数

1．引言对于理想化的并行计算机模型山,一个并行算法的加速定义为初二万／几一地小,效率定义为Ea二Sa／a二万／（aTa）二Va／（aVI）,其中a为并行计算机的等效处理机数目,乃为已知最快的串行算法在单处理机上的运行时间,凡是所讨论的并行算法使用。个处理机的运行时间,VI为单个处理机求解问题的运算速度,而Va为0个处理机求解问题的运算速度．曼尼和几分别反映了算法并行性对计算时间改进的程度以及并行计算机处理能力发挥的程度,因此,它们是度量并行算法的有效性的重要参数．另外两个与之相人的重要参数分别为冗余度尼二几周l…     

工资上涨对我国物价和出口品成本的影响分析

近年来我国劳动者报酬增速低于国内增加值(GDP)增速,居民收入水平提高较慢.提高各部门工资水平、增加居民收入、使得居民收入与GDP同步增长成为保证我国经济快速稳定增长的必要措施.2010年我国大部分省市将最低工资标准提高20%以上,作者提出了新的区分加工出口的非竞争型投入产出价格模型,并推导出工资水平提高对我国物价以及出口品成本的影响公式.实际测算结果表明,工资上涨带来的通货膨胀及对出口品成本影响较小,我国应该及时出台相应的政策措施提高各部门工资水平.