一个包含Smarandache函数的复合函数

对任意正整数n,著名的Smarandache函数S(n)定义为最小的正整数m使得n|m!,或者S(n)=min{m∶n|m!,m∈N}.而函数Z(n)定义为最小的正整数k使得n≤k(k 1)/2,即就是Z(n)=min{k:n≤k(k 1)/2}.本文的主要目的是利用初等及解析方法研究复合函数S(Z(n))的均值,并给出一个较强的渐近公式.     

二项式系数奇偶性的判定准则

判定准则Cnm(m≤n)的奇偶性取决于m和n-m的二进制表达式中是否存在位于同一数位上的两个数码都是1,如果存在,Cmn是偶数,否则Cnm就是奇数.证m=0时,Cnm=C0n=1总是奇数,判定准则显然成立.m=1时,Cnm=C1n=n,若n是奇数,则n-m=n-1是偶数,其二进制表达式的末位是0;若n是偶数,则n-m=n-1是奇数,其二进制表达式的末位是1,判定准则亦成立.可见,m=0或1时,判定准则对任意正整数n都成立.由于Cnm=Cnn-m,因此下面只需在m≥2且n-m≥2的前提下证明判定准则.以下对n使用数学归纳法证明判定准则.n=1时,m=0或1,前面已经证明判定准则成立.假设判定准则对n-1(≥1…     

一类数论函数及其均值分布性质

设正整数n≥ 3,对任一整数1≤a≤n-1且(a,n)=1,显然存在唯一的整数1≤(?)≤n-1使得a(?)≡1(mod n).本文的主要目的是研究差式|a-(?)|的分布性质,给出均值函数:M(n,k)≡sum fron a=1 to n-1(1/n)|a-(?)|~(2k 1)的一个较强的渐近公式.     

世界各地数学奥林匹克试题摘编

1(2000年中国台湾数学奥林匹克)设f是正整数集到非负整数集的映射.满足f(1)=0,f(n)=max1≤j≤n-1{f(j) f(n-j) j}(n≥2).求f(2000).解我们用数学归纳法证明f(n)=n(n-1)2(n≥1).当n=1时,结论成立.当n=2时,f(2)=f(1) f(1)-1=1.易知f(3)=max{f(1) f(2) 1,f(2) f(1) 2}=3,f(4)=6.假定n≥5,并且f(k)=k(k-1)2对于1≤k相似文献   

关于Smarandache函数S(n)与除数函数d(n)的混合均值

对于任意的正整数n,著名的Smarandache函数S(n)定义为最小的正整数m,使得n|m!,即就是S(n)=min{m:n|m!,m ∈N).本文的主要目的是应用初等方法研究S(n)与除数函数d(n)的加权均值问题,并获得一个有趣的渐进公式.     

布尔矩阵行空间基数的存在点

设Bn表示所有的n阶布尔矩阵的集合，R(A)表示A∈Bn的行空间．|R(A)|表示R（A）的基数。设m，n,k为正整数，本证明了当n≥9,[n 5/2]≤k≤n-3时,对任意的m、2^k≤m≤2^k 2^n-k 2 2^n-k 1 … 2^3，存在A∈B．使得|R（A）|=m．     

一个最值问题的求解方法

文[1 ] 对如下问题进行了研究 :已知实数x1 ,x2 ,… ,xn 满足x21 +x22 +… +x2 n= 1 ,当n≥ 3时 ,求maxi≠j mini≠j|xi-xj|.本文给出如下简捷解法 .由题意 ,不妨设x1 ≤x2 ≤…≤xn -1 ≤xn,并令mini≠j|xi-xj|=min|xi+ 1 -xi|=a(i=1 ,2 ,… ,n - 1 ) .则当 j>i时 ,xj-xi=(xj-xj-1 ) +… +(xi+ 1 -xi)≥(j-i)a∴ ∑1≤i相似文献   

互质数对的某些性质

本文据互质正整数 a,b 定义两个集合:P={p|1≤p≤ab,p=ma+nb,m,n,皆正整数},Q={q|q 为整数,a+b≤q≤ab,且任正整数 m,n,都有 q(?)ma+nb}.证明了 P,Q所含元素个数皆为((a-1)(b-1))/(2),且 P 与 Q 在数轴上,对称于点 (ab+a+b)/2.在 P 中定义了链(即 P 的极大连续整数子集),给出链的个数的计算方法.指出(a,b)=1,a>1,b>1的四种等价说法,讨论了以不全是1的正整数 r,u 为系数的二元二次方程 xy+1=rx+uy 的正整数解的个数,并给出求解方法.     

一个包含Smarandache函数的方程

对于任意正整数n,我们用S(n)表示Smarandache函数,即S(n)=min{m:n|m!}.本文的主要目的是运用初等方法研究方程∑_(d|n)S(d)=n的可解性,并给出它的所有正整数解.     

伪Smarandache函数的上下界

对于正整数n,设Z(n)=min{m|m∈N,1/2m(m+1)≡0(modn)},称为n的伪Smarandache函数.设r是正整数.根据广义Ramanujan-Nagell方程的结果,运用初等数论方法证明了下列结果:i)1/2(-1+(8n+1)≤Z(n)≤2n-1.ii)当r≠1,2,3或5时,Z(2~r+1)≥1/2(-1+(2~(r+3)·5+41)).iii)当r≠1,2,3,4或12时,Z(2~r-1)≥1/2(-1+(2~(r+3)·3-23).     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Bounds for the zeros of polynomials

Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.     

Boundedness of commutators related to Marcinkiewicz integrals on hardy type spaces

In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 ＜β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 ＜α≤ 1).     

Generalization of the interaction between Haar approximation and polynomial operators to higher order methods

In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f（u） of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.     

Jacobi polynomials used to invert the laplace transform

Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.