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1.
§1Introductionandresults A2-parameterGaussianprocess{Z(t,s);t,s≥0}iacalleda2-parameterfractional Wienerprocesswithorderα(0<α<1),ifZ(0,0)=0a.s.EZ(s,t)=0anditscovariance EZ(t1,s1)Z(t2,s2)={|t1|2α+|t2|2α-|t2-t1|2α}{|s1|2α+|s2|2α-|s2-s1|2α}/4.LetR=[x1,x2]×[y1,y2],DT={(x,y)∶0≤x,y≤bT,xy≤T}.Let0相似文献   

2.
研究了循环环R=的理想、素理想和极大理想的个数和结构,得到了如下结论:1)理想:(1)若|R|=∞,则R共有无穷多个理想:;(2)若|R|=n,设n的正因数个数为T(n),则R共有T(n)个理想:.2)素理想:(1)若|R|=∞,设a^2=ka(k≥0),①当k=0时,R的素理想只有R;②当k>0时,R的素理想共有无穷多个,它们是:{0}、R及;(2)若|R|=n>1,设a^2=ka,0≤k.3)极大理想:(1)若|R|=∞,则R有无限多个极大理想,它们是;(2)若|R|=n>1,设n的互不相同的素因数个数为ψ(n),则R共有ψ(n)个极大理想:(pa|p是n的素因数).  相似文献   

3.
Certain oscillatory integrals on unit square and their applications   总被引:3,自引:0,他引:3  
Let Q2 = [0, 1]2 be the unit square in two dimension Euclidean space R2. We study the Lp boundedness properties of the oscillatory integral operators Tα,β defined on the set S(R3) of Schwartz test functions f by Tα,βf(x,y,z) = Q2 f(x - t,y - s,z - tksj)e-it-β1s-β2t-1-α1s-1-α2dtds, where β1 > α1 0, β2 > α2 0 and (k, j) ∈ R2. As applications, we obtain some Lp boundedness results of rough singular integral operators on the product spaces.  相似文献   

4.
Let T 1 be an integer, T = {0, 1, 2,..., T- 1}. This paper is concerned with the existence of periodic solutions of the discrete first-order periodic boundary value problems△u(t)- a(t)u(t) = λu(t) + f(u(t- τ(t)))- h(t), t ∈ T,u(0) = u(T),where △u(t) = u(t + 1)- u(t), a : T → R and satisfies∏T-1t=0(1 + a(t)) = 1, τ : T → Z t- τ(t) ∈ T for t ∈ T, f : R → R is continuous and satisfies Landesman-Lazer type condition and h : T → R. The proofs of our main results are based on the Rabinowitz's global bifurcation theorem and Leray-Schauder degree.  相似文献   

5.
考虑3维的Navier-Stokes方程.当2/s+3/q=2-α,q>1,1<α+3/q<2且解的涡度ω=curlu满足∫T0(∫R3(|x-x0|αω)qdx)s/q dt<∞时,则∫T0∫R3|x-x01-1/2|▽ω|2dxdt<∞,特别地,解是正则的.若在T*处有∫T*0(∫R3(|x-x0|αω)qdx)s/q dt=∞,则解在此处爆破.这是Navier-Stokes方程正则性判别准则在加权情形的一个新结果.  相似文献   

6.
本文考虑了二阶差分系统-△~2u(t-1)=λf(v(t)),t∈[1,T]_z,-△~2v(t-1)=λg(u(t)),t∈[1,T]_z,u(0)=u(T+1)=0,v(0)=v(T+1)=0正解的存在性,其中f,g∈C([0,∞),R),λ0是参数.在f和g满足适当的假设条件下运用Schauder不动点定理证明了当λ充分大时差分系统正解的存在性.  相似文献   

7.
I1和I2分别是环R的一个左理想和右理想,T1=R[x]和T2=R[x,x-1]分别表示多项式环和洛朗多项式环.首先给出两个例子,分别说明了T1I1不一定是T1的左理想与T2L2不一定是T2的右理想.其次给出了环的多项式扩张及洛朗扩张的理想的性质.最后证明了,若R[X](R[x,x-1])是拟-Baer环,则R也是拟-...  相似文献   

8.
在数学教学中,充分利用教材中已编的题目,挖掘出它们的知识和方法内涵,对于减轻学生学业负担、提高教学质量是很有必要的.笔者曾对《平面解析几何》原教材第126面复习题第24题采用启发思维教学法,从5种不同思维角度引导学生进行分析、观察、思维、联想及解答,体会到这道题是培养学生发散思维能力的一道好题,现将教学中启发思维过程展现出来,仅供参考.题目 过圆外一点P(a,b),引圆x2+y2=R2的两条切线,求经过两个切点的直线方程.图1启发思路1目的:首先引导学生用自然思维程序——即用两点式求直线方程进行翻译、推理、思考.  T:求解该问题的自然思维是什么?S:求过A、B两点的直线方程.T:大家想一想困难是什么?S:A、B两点的坐标没有给出.T:那么能不能把切点A、B的坐标求出来呢?[提问学生甲]:设切点坐标为A(x0,y0),则由OA⊥AP得 y0-bx0-a.y0x0=-1,即   ax0+by0=R2.(1)又 点A适合方程,∴   x20+y20=R2.(2)由(1)、(2)消去y0有(a2+b2)x20-2aR2x0+R4-b2R2=0.(3)(教师此时有意停顿片刻,装出惊讶表情,学生窃窃私语——出现了一元二...  相似文献   

9.
1.IntroductionLetX,YberealHilbertspaces,T:X-Yab0ulldedlinear0perat0rwithnonclosedrangeR(T),yED(T+)=R(T)+R(T)",whereT+istheM0ore-PenroseinverseofTl11.Foreachb>0,lety6EYbesuchthatIly-ueIls6.(1)Asweknow,theproblemofsolvingtheoperatorequationofthefirstkindTx=y(2)..is,ingenerality,ill-p0sedl2].Alsowecann0tensurethatT+Wisareas0nableapproximation0fT+ysinceT+isaUnbounded0perat0r-Inpractice,onetriestoc0nstructastableaPprokimate6olutiontotheequation(2)byregularizationmeth0ds.Awell-knownregu…  相似文献   

10.
1 IntroductionThis paper is concerned with the problem of oscillation of second-orderquasilinear differential equationsFOr equation (1), the following conditions, which are referred to (FO), arealways assumed to be valid(a) a > 0 is a constant;(b) F: [to, co) x R x R x R x R - R is a continuous function;(c) sgn F(t, x) u? v3 w) = sgn x for each t 2 to and x, u? v? w E R,(d) r(t) E C([to, co); (0, co)) and jco ddt = co.' (e) T: [to, co) - R is continuous, T(t) 5 t for t 2 to and ill7T(t)…  相似文献   

11.
考虑了R~n上n(n≥2)维向列型液晶流(u,d)当初值属于Q_α~(-1)(R~n,R~n)×Q_α(R~n,S~2)(其中α∈(0,1))时Cauchy问题的适定性,这里的Q_α(R~n)最早由Essen,Janson,Peng和Xiao(见[Essen M,Janson S,Peng L,Xiao J.Q space of several real variables,Indiana Univ Math J,2000,49:575-615])引入,是指由R~n中满足的所有可测函数f全体所组成的空间.上式左端在取遍Rn中所有以l(I)为边长且边平行于坐标轴的立方体I的全体中取上确界,而Q_α~(-1)(R~n):=▽·Q_α(R~n).最后证明了解(u,d)在类C([0,T);Q_(α,T)~(-1)(R~n,R~n))∩L_(loc)~∞((0,T);L~∞(R~n,R~n))×C([0,T);Q_α,T(R~n,S~2))∩L_(loc)~∞((0,T);W~(1,∞)(R~n,S~2))(其中0T≤∞)中是唯一的.  相似文献   

12.
三维部分粘性Boussinesq方程的爆破准则   总被引:3,自引:0,他引:3  
本文主要讨论当扩散系数κ=0时,三维Boussinesq方程光滑解的爆破准则.利用空间分解技术和能量方法证明了如果压强满足π(x,t)∈Lq(0,T1;Brp,∞(R3)),2/q+3/p=2+r,3/2+rp≤∞,-1r1,则光滑解(u,θ)可以连续到TT1.  相似文献   

13.
The Chebyshev polynomials have good approximation properties which are not affected by boundary values. They have higher resolution near the boundary than in the interior and are suitable for problems in which the solution changes rapidly near the boundary. Also, they can be calculated by FFT. Thus they are used mostly for initial-boundary value problems for P.D.E.'s (see [1, 3-4, 6, 8-11]). Maday and Quarterom discussed the convergence of Legendre and Chebyshev spectral approximations to the steady Burgers equation. In this paper we consider Burgers-like equations.$$\begin{cases}∂_iu+F(u)_x-vu_{zx}=0, & -1≤x≤1, 0<t≤T \\ u (-1,t) =u (1,t) =0, & 0≤t≤T & (0.1)\\ u (x,0) =u_0(x), & -1≤x≤1\end{cases}$$ where $F\in C(R)$ and there exists a positive function $A\in C(R)$ and a constant $p>1$ such that $$|F(z+y)-F(z)|\leq A(z)(|y|+|y|^p).$$ We develop a Chebyshev spectral scheme and a pseudospectral scheme for solving (0.1) and establish their generalized stability and convergence.  相似文献   

14.
We consider finite volume relaxation schemes for multidimensional scalar conservation laws. These schemes are constructed by appropriate discretization of a relaxation system and it is shown to converge to the entropy solution of the conservation law with a rate of in .

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15.
Let $$\Omega \subset {\mathbb {R}}^N$$ be an arbitrary open set, $$0<s<1$$ and denote by $$(e^{-t(-\Delta )_{{{\mathbb {R}}}^N}^s})_{t\ge 0}$$ the semigroup on $$L^2({{\mathbb {R}}}^N)$$ generated by the fractional Laplace operator. In the first part of the paper, we show that if T is a self-adjoint semigroup on $$L^2(\Omega )$$ satisfying a fractional Gaussian estimate in the sense that $$|T(t)f|\le Me^{-bt(-\Delta )_{{{\mathbb {R}}}^N}^s}|f|$$, $$0\le t \le 1$$, $$f\in L^2(\Omega )$$, for some constants $$M\ge 1$$ and $$b\ge 0$$, then T defines a bounded holomorphic semigroup of angle $$\frac{\pi }{2}$$ that interpolates on $$L^p(\Omega )$$, $$1\le p<\infty $$. Using a duality argument, we prove that the same result also holds on the space of continuous functions. In the second part, we apply the above results to the realization of fractional order operators with the exterior Dirichlet conditions.  相似文献   

16.
In this paper,the authors obtain the existence of one-signed periodic solutions of the first-order functional difference equation ?u(n) = a(n)u(n)-λb(n)f(u(n-τ(n))),n ∈ Z by using global bifurcation techniques,where a,b:Z → [0,∞) are T-periodic functions with ∑T n=1 a(n) 0,∑T n=1 b(n) 0;τ:Z → Z is T-periodic function,λ 0 is a parameter;f ∈ C(R,R) and there exist two constants s_2 0 s_1 such that f(s_2) = f(0) = f(s_1) = 0,f(s) 0 for s ∈(0,s_1) ∪(s_1,∞),and f(s) 0 for s ∈(-∞,s_2) ∪(s_2,0).  相似文献   

17.
设X为实Banach空间, T:D(T)(?)X→2X*为极大单调算子, C: D(T)(?)X→X*为有界算子(未必连续),而C(T+J)-1为紧算子.本文在上述假设条件下,通过附加一定的边界条件应用Leray-Schauder度理论研究了下述包含关系:0∈(T+C)(D(T)∩ BQ(0)),0∈(T+C)(D(T)∩ BQ(0));以及S(?)R(T+C), intS(?)intR(T+C)(其中S(?) X*);B+D(?)R(T+C),int(B+D)(?)intR(T+C)(其中 B(?)X*,D(?)X*)的可解性,得出了一些新的结论.  相似文献   

18.
研究了欧氏空间R~2中单位方体Q~2=[0,1]~2上沿曲面(t,s,γ(t,s))的振荡奇异积分算子T_(α,β)f(u,v,x)=∫_(Q~2)f(u-t,v-s,x-γ(t,s))e~(it~(-β_1)s~(-β_2))t~(-1-α_1)s~(-1-α_2)dtds从Sobolev空间L_τ~p(R~(2+n))到L~p(R~(2+n))中的有界性,其中x∈R~n,(u,v)∈R~2,(t,s,γ(t,s))=(t,s,t~(P_1)s~(q_1),t~(p_2)s~(q_2),…,t~(p_n)s~(q_n))为R~(2+n)上一个曲面,且β_1α_1≥0,β_2α_20.这些结果推广和改进了R~3上的某些已知的结果.作为应用,得到了乘积空间上粗糖核奇异积分算子的Sobolev有界性.  相似文献   

19.
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