关于用多维样条逼近的饱和度

<正> 作者在工作[1]中,研究了一维样条逼近的饱和度问题,得到了下述定理: 定理A 设{△_k}是区间[a,b]的一分划序列,‖△_k‖→0(k→∞),R_(△k)≤β<∞(k=1,2,…),若f(x)∈c~n[a,b],S_(△_k)(x)是(n-1)次多项式样条,如果 对任一p成立,(p=0,1,…,n)则 D~nf(x)≡0. 本文是[1]的续篇,对多维样条进行研究,可得一些类似的结果,为明确起见,我们仅对二维情形进行讨论.     

二阶差分方程解的振动性与渐近性

本文研究了二阶差分方程Δ(a     

在零点的隣區內彼此相等的特徵函数

<正> §1.引言 大家知道,兩個不相恆等的特徵函數(以下简称特函)可以在零點的隣區內相等。為固定用語起見,在本文中我們說特函f(t)属於集合(U),如果存在一個特函,它与f(t)在零的隣區內相等,但並不恆等於f(t);如果f(t)不屬於(U),就說它屬於(U)。     

分数阶Schrodinger—Kirchhoff方程无穷多高能量解的存在性

本文研究如下带有变号势函数的分数阶Schrodinger Kirchhoff方程(a+b∫∫R^N|u(x)-u(y)|^p/|x-y|^N+p^sdxdy)^p-1(-△)p^su+λV(x)|u|^p-2u=f(x,u)-μg(x)|u|^q-2u,x∈R^N.其中s∈(0,1),p∈[2,∞),q∈(l,p),a,b>0,λ,μ>0均为正常数,在V,f,g等函数合适的条件下,运用喷泉定理获得该系统无穷多高能量解的存在性.     

CHARACTERIZATIONS OF COMPACT OPERATORS ON SOME EULER SPACES OF DIFFERENCE SEQUENCES OF ORDER m

In the past, several authors studied spaces of m-th order difference sequences, among them, H.Polat and F.Basar ([17]) defined the Euler spaces of m-th order difference sequences e r 0 (△ ( m ) ), e r c (△ ( m ) ) and e r ∞ (△ ( m ) ) and characterized some classes of matrix transformations on them. In our paper, we add a new supplementary aspect to their research by characterizing classes of compact operators on those spaces. For that purpose, the spaces are treated as the matrix domains of a triangle in the classical sequence spaces c 0 , c and ∞ . The main tool for our characterizations is the Hausdorff measure of noncompactness.     

带非奇扰动项的(2, p)-Laplace方程无穷多解的存在性

本文研究带非奇扰动项的(2,p)-Laplace方程{-△u-△pu=a(x)|u|q-2u+f(x,u),u=0, x∈Ω,x∈(e)Ω,其中Ω (∈) RN是有界光滑区域,1＜q＜2＜p＜N,a∈C((Ω))可变号,f关于u不必是奇函数.利用变分方法,本文获得该方程无穷多解的存在性.     

一类（p,q）-Laplacian椭圆方程组解的存在性

研究了P,q—Laplacian椭圆方程组-△pu=λf（x）u^8v^n,-△qv=μg（x）u^tv^m的Dirichlet边界值问题的正弱解的存在性．首先根据两个方程组构造了弱上解和弱下解,然后利用弱上下解方法得到了方程组正弱解的存在性．利用特征值和特征函数构造了弱上下解具有一定的创新性,结果推广了p=q=2的情...     

A NEW FAMILY OF FILTRATION S ＋ 5 IN THE STABLE HOMOTOPY GROUPS OF SPHERES

In this article, by the algebraic method, the author proves the existence of a new nontrivial family of filtration s ＋ 5 in the stable homotopy groups of spheres πrS,which is represented by 0 ≠γ^-s＋3hnhm∈Ext^s＋5,A ^t（Zp,Zp）in the Adams spectral sequence,where r=q（p^m＋p^n＋（s＋3）p^2＋（s＋2）p＋（s＋1））-5,t=p^mq＋p^nq＋（s＋3）p^2q＋（s＋2）pq＋（s＋1）q＋s,p≥7,m≥n＋2〉5,0≤s〈p-3,q=2（p-1）.     

Hénon方程基态解的集中性态

本文主要分析了含原点区域上零边界条件的H啨ｎｏｎ方程 -Δpu =|x|αuq - 1基态解的集中性态 ,证明了当q→p =np/(n -p) ,(n >p >1 )时 ,其基态解集中在区域的边界     

Sobolev Hardy不等式与临界双重调和问题

该文讨论一类带有奇异系数的双重调和方程〖JB({〗△2u-μ[SX(]u[]|x|s[SX)]=f(x,u),\=u=[SX(]u[]ν[SX)]=0,〖JB)〗\ \ 〖JB(〗x∈Ω,x∈Ω,[JB)] 这里ΩRN是包含0的有界光滑区域，u∈H20(Ω)，μ∈R是参数，0≤s≤2，△2=△△表示双重拉普拉斯算子.当f(x,u)=up,p=[SX(]2N[]N-4[SX)]时，上述问题就是一个临界双重调和问题. 该文运用Sobolev Hardy不等式和变分方法，得到它的解的存在性的一些结果.     

BLOW-UP AND GLOBAL EXISTENCE FOR A COUPLED SYSTEM OF DEGENERATE PARABOLIC EQUATIONS IN A BOUNDED DOMAIN

This article deals with the conditions that ensure the blow-up phenomenon or its absence for solutions of the system ut=△ul up1vq1 and vt=△vm up2vq2 with homogeneous Dirichlet boundary conditions. The results depend crucially on the sign of the difference p2q1-(l-P1)(m-q2), the initial data, and the domainΩ.     

一类具奇异势的拟线性椭圆方程的无穷多解

本文用变分法和集中紧性原理获得了一类具奇异势的拟线性椭圆方程-Δ_pu=μ(|μ|~(P~*(s)-2)u)/(|x|~s) λf(x,u),u∈H_0~(1,p)(Ω)的无穷多解．     

一类二阶多点时标边值问题无界解的存在性

借助不动点定理研究边值问题(φp(u△(t)))▽+f(t,u(t))=0,t∈(0,∞)Tu(0)=∑m-2i=1αiu(ηi),φp(u△(∞))=∑m-2i=1βiφp(u△(ηi))多个正解的存在性,得到了正解存在的充分条件.     

代數拓撲學中(μ,△,γ)-系統的正則同模論Ⅰ

<正> 設K與L為拓撲空間,又設f:K→L為連續映像.由f導出了準同模對應f~n:H~n(L,G)→H~n(K,G),n=1,2,…,其中H~n(L,G),H~n(K,G)表示上同調羣,而G表示係數環或域以γ_p~n(K)或者     

Alternating quotients of the (3.q.r) triangle groups

A long standing conjecture (attributed to Graham Higman) asserts that each of the triangle groups △(p,q,r)for 1/p+1/q+1/r>1 contains among its homomorphic images all but finitely many of the alternating or symmetric groups. This phenomenon has been termed property H by Mushtaq and Servatius [9]. The work of several authors over the last decade and a half has shown that for any value of q, there are only finitely many r such that△(2,q,r) fails to have property H. In this paper, the techniques used by these authors are generalised to handle the possinblity that p is odd, and as a result, it is shown that for any q≧3, there are only finitely many r such that △(3,q,r)fails to have property H.     

一个山路引理的应用

本文主要考虑如下形式的Dirichlet问题-△u(x)=f(x,u),x∈Ω,∈H01(Ω),其中f(x,t)∈C(Ω×R),f(x,t)/t关于t单调不减,并且当t∈R时关于x∈Ω一致趋向于某个L∞函数q(x)(此时,称f(x,t)关于t在无穷远处是渐近线性的).显然,在该条件下常用的Ambrosetti-Rabinowitz型条件,即关于所有的|s|>M和x∈Ω,0<θF(x,s)2,M>0为常数, F(x,s)=∫0s f(x,t)dt. 众所周知,条件(AR)在山路引理的应用中起着非常重要的作用.本文通过应用一种改进了的山路引理在没有条件(AR)的情况下来证明上面Dirichlet问题(P)也有正解存在。此方法也适用于f(x,t)关于t在无穷远处是超线性,即q(x)≡+∞的情形.     

凸函数的双参数平均不等式的新证明

利用 Tchebycheff积分不等式和积分形式的 Cauchy中值定理证明了下列结论 :设 f(x)是 [a,b]上的正连续函数 ,且在 (a,b)内可微 ,若 f′(x)单调递增 ,则对任意的 p,q,有 Mp,q(f) 相似文献   

THE TRACE SPACE INVARIANT AND UNITARY GROUP OF C^＊—ALGEBRA

Let A be a unital C-algebra, n ∈ N ∪ {∞}. It is proved that the isomorphism △n : is isometric for some suitable distances. Asan application, the author has the split exact sequence with iA contractive (and isometric if n = ∞) under certain condition of A.     

Antiferromagnetism,ferromagnetism and superconductivity in the Hubbard model with repulsion

A study has been made, using Green's functions for temperature, of the Hubbard model with repulsive interaction. The existence is demonstrated of an antiferromagnetic state in the case of a half-filled zone. The existence of a superconducting state with p-pairing in the three-dimensional model is shown for low densities of electrons or holes. The highest superconducting transition temperature is reached in a two-dimensional model when the saddle point of the energy function (Van Hove point) is situated on the Fermi surface. The type of superconducting pairing can be called superposition pairing with odd angular momenta (to a first approximation this is p-pairing). The problem of competition between superconductivity and ferromagnetism is discussed. It is shown that superconductivity is favored for u/t 8.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 189, pp. 153–180, 1991.     

一个带非线性边界条件的强耦合抛物方程组的整体存在性与爆破

本文处理带非线性边界条件 u n=uα, v n=vβ ,(x ,t) ∈ Ω× (0 ,T)的抛物方程组ut =vpΔu ,vt=uqΔv ,(x ,t) ∈Ω× (0 ,T) ,其中Ω RN 为一个有界区域 ,p ,q>0和α ,β≥ 0为常数 .研究了上述问题正解的整体存在性和爆破 ,建立了整体存在和爆破的新标准 .证明了当max{p+β,q+α}≤ 1时正解 (u ,v)整体存在 ,当min{p+β ,q+α}>1且max{α ,β}<1时正解 (u ,v)在有限时刻爆破