共查询到20条相似文献,搜索用时 62 毫秒
1.
本文讨论了超空间2x的某些局部覆盖性质,并给出下面二个结果:定理1设X是T2空间,则2x紧当且仅当2x是局部meta-Lindelof空间.定理21设X是T1空间,则2xm-紧当且仅当2x是局部m-紧。 相似文献
3.
有面积的曲线的性质及高维推广 总被引:1,自引:0,他引:1
本文研究平面上有面积的曲线的分形性质及其在d维欧氏空间Ed中的推广.对瘦分形曲线,分维Df=ln2d/ln(2/k1/d),而对于胖分形曲线,分形指教β=-lnk/ln2.α=d.d=2时的胖分形曲线包括经典的Pcano曲线为其特例。 相似文献
4.
本文讨论了在有限部分具有三个奇点的二次系统E23的极限环线分布问题.证明了E23在有一个高次奇点的条件下,极限环线是集中分布的. 相似文献
5.
本文主要探讨下列周期系数微分方程dy/dt=(A1(t)y+A2(t)y2+A3(t)y3)/(a0(t)+a1(t)y+a2(t)y2)(**)的周期解个数问题,利用方程(**)解的差率法得到了方程(**)周期解的个数定理.本文仅在Ai(t),aj(t)(i=1,2,3,j=0,1,2)是连续周期函数的条件下得到这一结论,从而减弱了文[2]中相应定理的条件,即Ai(t),aj(t)均是连续可微的周期函数. 相似文献
6.
关于二部图K(m,n)-2的色唯一性 总被引:7,自引:0,他引:7
设K(m,n)-2表示从完全二部图K(m,n)中删去任意2条边所得之图.本文证明了:1.若n≥m≥3,且n+m>((n-m)2+8)1/2+1/2(n-m)2+4,则K(m,n)-2是色唯一图;2.当m≥3时,K(m,m)-2,K(m,m+1)-2和K(m,m+2)-2均是色唯一图. 相似文献
7.
本文证明了d2k =δ2k =d2k ≥b2k,其中d2k ,δ2k , b2k分别表示A(BlMp)在lNq下的Kolmogorov,线性,Bernstein 2k-宽度,d2k 表示AT(BlN相似文献
8.
本文利用平行变换,得到3维Minkowski空间R2,1中的K-2mH+m2-l2=0(H2> K,0≤m<l)类时Weingarten曲面的B?cklund定理. 相似文献
9.
本文讨论了积流形的P-形式上Laplace算子谱的唯一性问题,在紧Kachler流形乘积和紧Sasaki流形乘积的两类积流形中,CPn×CPn和S2n+1(1)×S2n+1(1)是P-形式上Laplacce算子谱特征。 相似文献
10.
文献[1],[2],[3]中讨论了Rn上的局部Hardy空间,并利用乘子定理证明了hp(Rn)=Fp.20(Rn).本文利用Chebyshev等式及正则函数的性质证明了在局部域上有类似的结果hp(Rn)=Fp.20(Rn),从而建立起函数空间之间的关系,并由此给出一个乘子定理. 相似文献
11.
Kunyang Wang Feng Dai 《分析论及其应用》2007,23(1):50-63
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. 相似文献
12.
H. H. Cuenya M.D. Lorenzo C. N. Rodriguez 《分析论及其应用》2007,23(2):162-170
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. 相似文献
13.
Yuxian Zheng 《分析论及其应用》2006,22(2):136-140
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. 相似文献
14.
15.
《计算数学》2014,(2)
<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 相似文献
16.
《中国科学 数学(英文版)》2014,(8)
<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 相似文献
17.
W.M.Shah A.Liman 《分析论及其应用》2004,20(1):16-27
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. 相似文献
18.
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). 相似文献
19.
A.Al-Shuaibi F.Al-Rawjih 《分析论及其应用》2004,20(1):28-34
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. 相似文献
20.
Francois Chaplais 《分析论及其应用》2006,22(4):301-318
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. 相似文献