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1.
胡克 《数学学报》1954,4(2):259-262
毅奇函教叔约=C十艺。。C一2“’在co>}C}>1内是正4lJ且翠案.戈鲁泽「王]、夏道行「21曾覆明镇}氢客式‘’og以匕)一F(C:’) 匕一C了 匕+吠尸(C二)+F(C二,)(艺:二补1oz乙,+1孔,一1艺:了衫(1),一v诊=1,__己己+lIUg一二万屯万厂一二尸, ‘v‘,,一1匕一匕喀客‘厂‘ogF(C二),一r(乙了), 打一C份2《、、,/ 一住,拼,砰t=l_,,/,1、Y二“09、‘一,音万万万少、艺刃衫l,,‘=1乙份乙(2) 下.艺 成1艺一‘·丫”。gI卜.v=1卫义力一F(乙,) 乙,一二 C,+CvF(C,)+F(C,)l。。(;-}、《艺a,,·下二下·109C,万,+1乳乙一l(3)”,v=l艺a,,,丫二丫,l。g…  相似文献   

2.
胡世華 《数学学报》1956,6(1):93-104
<正> §1.引言設f(x)=1/g(x).我們把連分數  相似文献   

3.
发展方程长时间计算的稳定性与收敛性   总被引:1,自引:0,他引:1  
本文是[5]的继续,作者在[5]中从稳定性与收敛性之间的关系入手,研究了半线性发展方程数值法的长时间误差估计,那里要求离散化方程当tn=nτ充分大后在某种较严格的意义下稳定,这限制了它的应用范围,本文引进γ-相容的概念,证明由γ-相容和较弱意义下的稳定性可以推出 收敛性,特别对齐次线性和初值问题的差分格式得到了无穷时域上的Lax等价定理,本文2引进γ-相容的概念,并就齐次线性初值问题的差分格式,给出Lax等价定理对无穷时域的推广,3讨论非线性初值问题的数值逼近,对全离散逼近,我们给出两类由长时间稳定(严格稳定)+γ-相容(相容)无穷时域上收敛性的定量,由于γ-相容性对偏微分方程(同时含有时间和人间变量)通常比对常微分方程组(只含有时间变量)更难检验,为此,我们特别针对常微分方程组数值解给出第三个收敛性定理,我们知道偏微分方程(组)半离散化就是常微分方程组,若能证明半离散解的长时间收敛性,我们就可以利用这一定理证明全离散解的长时间收敛性了,最后在3,作为应用我们指出,可以利用本文方法证明[2]和[4]的结果。并改进[1]的结果。γ  相似文献   

4.
61. IntroductionLet G be a discrete (not necessarily abelian) group. For any subset G of G, we saythat (G, G ) is a quasi-partial ordered group if e 6 G , G ' G G G and G = G ' G ',where e is the unit of G and G ' = {g--' I g e G }; further, (G, G ) is referred to as aquasi-ordered group if G = G u G '. Note that when G7 = G n G ' = {e}, a quasi-partial ordered group (resp. quasi-ordered group) (G, G ) is known as a pajrtially ordered(resp. ordered) group.Let { 6, I g e G } b…  相似文献   

5.
For the two-dimensional Navier-Stokes equations of isentropic magnetohydrodynamics(MHD)withγ-law gas equation of state,γ≥1,and infinite electrical resistivity,we carry out a global analysis categorizing all possible viscous shock profiles.Precisely,we show that the phase portrait of the traveling-wave ODE generically consists of either two rest points connected by a viscous Lax profile,or else four rest points,two saddles and two nodes.In the latter configuration,which rest points are connected by profiles depends on the ratio of viscosities,and can involve Lax,overcompressive,or undercompressive shock profiles.Considered as three-dimensional solutions,undercompressive shocks are Lax-type(Alfven)waves.For the monatomic and diatomic casesγ=5/3 andγ=7/5,with standard viscosity ratio for a nonmagnetic gas,we find numerically that the the nodes are connected by a family of overcompressive profiles bounded by Lax profiles connecting saddles to nodes,with no undercompressive shocks occurring.We carry out a systematic numerical Evans function analysis indicating that all of these two-dimensional shock profiles are linearly and nonlinearly stable,both with respect to two-and three-dimensional perturbations.For the same gas constants,but different viscosity ratios,we investigate also cases for which undercompressive shocks appear;these are seen numerically to be stable as well,both with respect to two-dimensional and(in the neutral sense of convergence to nearby Riemann solutions)three-dimensional perturbations.  相似文献   

6.
《Quaestiones Mathematicae》2013,36(1-2):291-313
Abstract

A 0-dominating function 0DF of a graph G = (V,E) is a function f: V → [0,1] such that Σ xεN(v) f(x) ≥ 1 for each ν ε V with f(v) = 0. The aggregate of a 0DF f is defined by ag(f) = ΣvεV f(v) and the infimum and supremum of the set of aggregates over all minimal 0DFs of a graph are denoted by γ0 and Γ0 respectively. We prove some properties of minimal 0DFs and determine γ0 and Γ0 for some classes of graphs.  相似文献   

7.
设本文给出了一类新的Lipschitz B-(p,γ)-不变凸函数,它是B-不变凸函数和(p,γ)-不变凸函数的推广.在这类Lipschitz B-(p,γ)一不变凸性下,建立了非光滑规划的必要和充分最优性条件,讨论了Mond-Weir型对偶和Wolfe型对偶,证明了弱对偶、强对偶和逆对偶定理.所得结果推广了涉及凸函数、B-不变凸函数和(p,γ)-不变凸函数的规划问题的相应结果.  相似文献   

8.
关于非负矩阵优势比的界   总被引:1,自引:0,他引:1  
佟文廷 《数学学报》1979,22(2):185-194
令A为一n×n复矩阵,且令这个比率d称为矩阵A的优势比.1964年,Ostrowski得到正矩阵优势比的一个界.1974年,Ostrowski又得到既约非负矩阵优势比的一个界. 在本文中,我们得一个比[4]更好的界,我们的结果还推广到类似于既约非负矩阵的另一类矩阵,即在[1]中定义的准非负矩阵.此外,我们还给出确定本原指标v(A)的一个简单方法,这样可以得到优势比的更佳界.  相似文献   

9.
《分析论及其应用》2012,28(1):79-86
In this paper,we establish two weighted integral inequalities for commutators of fractional Hardy operators with Besov-Lipschitz functions.The main result is that this kind of commutator,denoted by Hb α,is bounded from L x γp (R +) to Lx δ q (R +) with the bound explicitly worked out.  相似文献   

10.
γ-稳定图     
叶淼林  戴林送 《应用数学》2005,18(3):381-383
本文我们引进γ- 稳定图,γ 稳定图和γ稳定图的概念,图G是γ- 稳定图(γ 稳定图),若任意删去G(增加G)的一条边都不改变G的控制数γ(G).一个γ稳定图指既是γ- 稳定图又是γ 稳定图的图.我们给出一些γ-(γ ,γ) 稳定图的性质和实例.  相似文献   

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