差异张量平行和半平行的仿射超曲面

本文用活动标架法证明了：若 Ｍｎ（ｎ≥２）是 ｎ＋１维仿射空间 Ａｎ＋１中非退化的仿射超曲面,（１）若■Ｋ＝０（即差异张量平行）,则Ｍ是仿射球,且Ｊ＝０和Ｇ是一个Ｅｉｎｓｔｅｉｎ度量,这里Ｊ是Ｍ的 Ｐｉｃｋ不变量,Ｇ是Ｂｌａｓｃｈｋｅ度量;（２）Ｒ·Ｋ＝０（即差异张量半平行）当且仅当Ｓ＝０（Ｍ为虚仿射球）,或者Ｋ＝０（Ｍ为非退化的二次超曲面）,这里 Ｒ为诱导仿射联络 ■的黎曼曲率算子．     

Hadamard积和酉不变范数不等式

设Ｍｎ，ｍ是ｎ×ｍ复矩阵空间，Ｍｎ≡Ｍｎ，ｎ．对于Ｈｅｒｍｉｔｅ阵Ｇ，Ｈ∈Ｍｎ，ＧＨ表示Ｇ－Ｈ半正定．记Ａ和Ｂ的Ｈａｄａｍａｒｄ积为ＡＢ．本文证明了若Ａ，Ｂ∈Ｍｎ正定，而Ｘ，Ｙ∈Ｍｎ，ｍ任意，则（ＸＡ－１Ｘ）（ＹＢ－１Ｙ）（ＸＹ）（ＡＢ）－１（ＸＹ），ＸＡ－１Ｘ＋ＹＢ－１Ｙ（Ｘ＋Ｙ）（Ａ＋Ｂ）－１（Ｘ＋Ｙ）．这推广和统一了一些现存的结果．设‖·‖为任意酉不变范数，Ｉ是单位矩阵．本文还证明了对于Ｘ∈Ｍｎ，ｍ和Ａ∈Ｍｎ，Ｂ∈Ｍｍ，若ＡＩ，ＢＩ，则函数ｆ（ｐ）＝‖ＡｐＸ＋ＸＢｐ‖在［０，∞）上单调递增．     

UNIFORM CONVERGENCY FOR WEIGHTED PERIODOGRAM OF STATIONARY LINEAR RANDOM FIELDS

ＵＮＩＦＯＲＭＣＯＮＶＥＲＧＥＮＣＹＦＯＲＷＥＩＧＨＴＥＤＰＥＲＩＯＤＯＧＲＡＭＯＦＳＴＡＴＩＯＮＡＲＹＬＩＮＥＡＲＲＡＮＤＯＭＦＩＥＬＤＳ￥ＨＥＳＨＵＹＵＡＮＡｂｓｔｒａｃｔ：Ｌｅｔ｛Ｘｎ；ｎ∈Ｎ２｝ｂｅａｔｗｏｄｉｍｅｎｓｉｏｎａｌｌｙｉｎｄｅｘ...     

TOPOLOGICAL STRUCTURE OF HIGHER ORDER SINGULAR POINT OF PLANE n－DEGREE DIFFERENTIAL SYSTEM WITH TWO ZERO CHARACTERISTIC ROOTS

ＴＯＰＯＬＯＧＩＣＡＬＳＴＲＵＣＴＵＲＥＯＦＨＩＧＨＥＲＯＲＤＥＲＳＩＮＧＵＬＡＲＰＯＩＮＴＯＦＰＬＡＮＥｎ－ＤＥＧＲＥＥＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭＷＩＴＨＴＷＯＺＥＲＯＣＨＡＲＡＣＴＥＲＩＳＴＩＣＲＯＯＴＳＬｉＸｕｅｍｉｎ（李学敏）（Ｓｈ...     

EXPONENTIAL STABILITY OF LINEAR TIME－VARYING IMPULSIVE DIFFERENTIAL SYSTEMS WITHDELAYS

ＥＸＰＯＮＥＮＴＩＡＬＳＴＡＢＩＬＩＴＹＯＦＬＩＮＥＡＲＴＩＭＥ－ＶＡＲＹＩＮＧＩＭＰＵＬＳＩＶＥＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭＳＷＩＴＨＤＥＬＡＹＳ￥ＧｕａｎＺｈｉｈｏｎｇ（关治洪）；ＬｉｕＹｏｎｇｑｉｎｇ（刘永清）（ＳｏｕｔｈＣｈｉｎａＵｎ...     

体积法解一道微积分题

问题　求由曲线ｙ =x~2 在x轴正半轴与直线x=ｎ所围成的图形的面积Ｓ .此题已超出高一所学的知识范围 ,但我们合理运用祖日恒原理 ,化未知为已知 ,利用等体积的方法求解 .解　如图 ,构造正四棱锥Ｏ ＡＢＣＤ ,底面边长ＡＢ=ｎ ,高ＯＥ =ｎ ;又构造柱体ＯＨ ,以ＯＨＫ为中截面 ,高ＦＧ =1 .(其中ＯＨＫ即是曲线ｙ =ｘ2 与ｘ轴正半轴及直线ｘ =ｎ围成的图形 ) .设任一平行于底面的截面到点Ｏ的距离为ｘ ,则两截面的面积均为ｘ2 ,即有ＳⅠ =ＳⅡ .根据祖日恒原理 ,得ＶⅠ =ＶⅡ .∵　ＶⅡ =13 Ｓ底 ｈ =13 ＳＡＢＣＤ·ＯＥ =ｎ33 ,∴　ＶⅠ =…     

APPROXIMATION OF GENERALIZED BI－AXIALLY SYMMETRIC POTENTIALS WITH FAST RATES OF GROWTH

ＡＰＰＲＯＸＩＭＡＴＩＯＮＯＦＧＥＮＥＲＡＬＩＺＥＤＢＩ－ＡＸＩＡＬＬＹＳＹＭＭＥＴＲＩＣＰＯＴＥＮＴＩＡＬＳＷＩＴＨＦＡＳＴＲＡＴＥＳＯＦＧＲＯＷＴＨ￥Ｈ．Ｓ．Ｋａｓａｎａ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＢｉｒｌａＩｕｓｔ．ｏｆＴｅｃｈ．＆Ｓｃｉ．，Ｐ...     

ON THE HARISH－CHANDRA HOMOMORPHISM FOR THE CHEVALLEY GROUPS OVER P－ADIC FIELD

ＯＮＴＨＥＨＡＲＩＳＨ－ＣＨＡＮＤＲＡＨＯＭＯＭＯＲＰＨＩＳＭＦＯＲＴＨＥＣＨＥＶＡＬＬＥＹＧＲＯＵＰＳＯＶＥＲＰ－ＡＤＩＣＦＩＥＬＤ￥ＣＨＥＮＺＨＯＮＧＨＵ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＸｉａｎｇｔａｎＵｎｉｖｅｒｓｉｔｙｔＸｉ...     

一类有趣的几何连比题

应用九年义务教材初中《几何》第二册第 2 5 5页第1 7题“过△ＡＢＣ的顶点Ｃ任作一直线 ,与边ＡＢ及中线ＡＤ分别交于点Ｆ和Ｅ ,求证 :ＡＥ∶ＥＤ =2ＡＦ∶ＦＢ”(图 1 ,图 2 )可巧解一类有趣的几何连比问题例 1　如图 3 ,△ＡＢＣ中 ,ＡＤ是中线 ,Ｅ在ＡＣ上 ,Ｆ在ＡＢ上 ,且ＡＥ∶ＥＣ =5∶4,ＡＦ∶ＦＢ =2∶3 .又ＣＦ ,ＢＥ分别交ＡＤ于Ｇ ,Ｈ ,则ＡＧ∶ＧＨ∶ＨＤ =.解 :设ＡＧ =ｘ ,ＧＨ =ｙ,ＨＤ =ｚ ,则由课本习题结论得　ｘｙ +ｚ=2ＡＦＦＢ =2× 23 =43 ,ｘ +ｙｚ =2ＡＥＥＣ =2× 54=52 .化简得 3ｘ -4ｙ =4ｚ ,2ｘ +2 ｙ =5ｚ .…     

ON EXCHANGE ALGORITHM FOR NONLINEAR BEST CHEBYSHEV APPROXIMATION WITH LGH CONDITION

ＯＮＥＸＣＨＡＮＧＥＡＬＧＯＲＩＴＨＭＦＯＲＮＯＮＬＩＮＥＡＲＢＥＳＴＣＨＥＢＹＳＨＥＶＡＰＰＲＯＸＩＭＡＴＩＯＮＷＩＴＨ　ＬＧＨＣＯＮＤＩＴＩＯＮＸｉｏｎｇＧｕｉｊｉｎｇ（熊规景）；ＷｅｉＤａｎ（韦旦）（Ｉｎｓｔ．ｏｆＭａｔｈ．Ｓｃｉ．，Ｃｈｉｎ．...     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

Qualitative Analysis of Bifurcating Solutions in the Lengyel-Epstein Model

One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the＇living world. In his seminal paper ＂The Chemical Basis of Morphogenesis＂, Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates（1990） on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing＇s prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

(0,1 ;0)-INTERPOLATION ON INFINITE INTERVAL (-∞, +∞)

In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].