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1.
定理1设R是半值环,n为固定的正整数,如果R满足条件:存在依赖于(?)x,y的两个字k(X,Y),t(X,Y),其中|k|X>1,|t|X=1,|k|Y≥|t|Y,|t|Y≤n,使k(x,y)-t(x,y)∈I(R),则R是交换环。定理2设R是半值环,如果R满足条件:存在正整数m=m(x,y)>1,n=n(y),使得(xy)m-x  相似文献   

2.
§ 1.Introduction Letabeameasurablefunction ,bea φ∈S(R)nonnegativefunction ,and 0 <r <∞ .Definecommutatorsasfollows :Cra( f) (x) =supx∈Q1|Q|∫Q|a(x) -a( y) |r|f( y) |dy ,( 1 .1 )andΦra( f) (x) =supε>0∫Rn|a(x) -a( y) |rφε( |x- y|)|f( y) |dy ,( 1 .2 )whereQdenotesacubeandφε(t) =1εnφ tε .Thesetwooperat…  相似文献   

3.
一、选择题1.设集合M={x|22-x≥1},集合N={x|x2-2x-3<0},集合M∩N=()(A){x|0≤x<1}(B){x|0≤x<2}(C){x|0≤x≤1}(D){x|0≤x≤2}2.已知函数f(x)=2x,则函数y=|f-1(x-1...  相似文献   

4.
1 IntroductionInthispaper,weconsiderthefollowingperiodicinitialvalueproblemforthesystemofGinzburg LandauequationscoupledwithBBMequations:x∈Rεt+ με-(α1+iα2 )εxx+ (β1+iβ2 ) |ε|2 ε-iδnε=g1(x) ,(1 .1 )nt+ f(n) x+λn-αnxx-nxxt+ |ε|2 x =g2 (x) ,(1 .2 )ε(x+ 2π ,t) =ε(x ,t) ,n(x + 2π ,t) =n(x ,t) ,(1 .3)ε(x ,0 )…  相似文献   

5.
§1.IntroductionConsiderthefolowingddimensionalVlasovPoisonsystem,d=2,3,tf+v·xf-E·vf=0,f(0,x,v)=f0(x,v),E(t,x)=c(d)∫x-y|x...  相似文献   

6.
丁勇 《数学进展》1998,27(2):159-165
本文给出了一类带粗糙核的分数次振荡积分算子Tμ,Tμf(x)=∫RneiP(x,y)Ω(x-y)|x-y|n-μh(|x-y|)f(y)dy的加权Lp(Rn)有界性.这里P(x,y)是Rn×Rn上非平凡的实多项式,Ω∈Lq(Sn-1)为零阶齐次函数,且h(r)∈BV(R+).作为推论,证明了Tμ和BMO函数形成的高阶交换子Tμ,b,Tμ,bf(x)=∫RneiP(x,y)Ω(x-y)|x-y|n-μh(|x-y|)[b(x)-b(y)]mf(y)dy也是加权Lp(Rn)有界的,其中b(x)∈BMO(Rn),m∈Z+  相似文献   

7.
带粗糙核的多线性振荡奇异积分   总被引:2,自引:0,他引:2  
胡国恩 《数学进展》1997,26(1):50-59
本文考虑多线性算子TAf(x)=∫RneiP(x,y)Ω(x-y)|x-y|n+mRm+1(A;x,y)f(y)dy,n2,其中P(x,y)是Rn×Rn中的实值多项式,Ω是零次齐次函数且满足m阶消失性条件,Rm+1(A;x,y)=A(x)-|α|mDαA(y)(x-y)α,对任何|α|=m,DαA∈BMO(Rn).证明了Ω∈Lq(Sn-1)且q>1时,对任何1<p<∞,‖TAf‖pC(n,m,p,degP)|α|=m‖DαA‖BMO‖f‖p  相似文献   

8.
本文讨论问题 ut=Auxx+f(x,t,u), ux|x=0=0,ux|x=1=0, u|t=0=u0(x)。 的解的渐近性质,将参考文献[1]的L^2范数估计  相似文献   

9.
本文应用微分不等式的方法,研究非线性Robin边值问题:a(x,y,y′,ε)y″=f(x,y,y′,ε),0<x<1,p1y(0,ε)-p2y′(0,ε)=A(ε),q1y(1,ε)+q2y′(1,ε)=B(ε),{其中ε>0是小参数,在适当的假设条件下,我们证明了上述问题解y(x,ε)的存在性和渐近估计式.  相似文献   

10.
一类n阶拟线性奇异摄动边值问题的一致有效渐近展开   总被引:1,自引:0,他引:1  
本文研究一类n阶拟线性奇异摄动边值问题:εy(n)=f(t,ε,y,…,y(n-2)y(n-1)+g(t,ε,y,…,y(n-2),pj(ε)y(j)(0,ε)-qj(ε)y(j+1)(0,ε)=αj(ε)(0≤j≤n-2),b1(ε)y(n-2)(1,ε)+b2(ε)y(n-1)(1,ε)=β(ε),其中ε>0为小参数.在较一般的条件之下,应用Banach/Picard不动点定理证明了摄动解的存在性及局部唯一性,并给出了摄动解直到n阶导函数的一致有效渐近展开式,推广和改进了已有的结果[1-5].  相似文献   

11.
12.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
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  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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).  相似文献   

16.
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.  相似文献   

17.
18.
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  相似文献   

19.
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.  相似文献   

20.
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].  相似文献   

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