首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
设k≥2,且Hk表示一个正整数n的集合,使得该集合中的元素满足a+bk≡n(modq)对任意的q,在模q的既约剩余系中有解,令Dk(N)表示所有的n≤N,且n∈Hk且不能表成p1+p2k=n形式的整数.那么在GRH下, Dk(N)相似文献   

2.
1 IntroductionConsider the fOllowing Logistic modelwhere A denotes the forward difference operator defined by Ax. = xu l -- x.,{r.}7=, is a sequence of nonnegative real number, {k.}7=, is a sequence ofnonnegative integers, which satisfies j\t(n -- k.) = co) }it sup k. = co? andK is a positive constant. Obviously, K is the unique positive equilibrium pointof Eq.(1).FOr the special cases of Eq.(l)f re = r > 0 or k. == k 6 {0, 1, 2,' .}, therehave been many papers studying them. See, for exa…  相似文献   

3.
1 IntroductionIn this paper, we study the nib order difference equation'L.Xk qkf(X,,) = 0, k E N(0) = {0, 1, 2,' .} (E)where A is the forward difference operator, i.e. axs = xk 1 -- xkj Loxk = xk?L.xk = ac(L.--lxk), in = 1, 2,'', n; {alk},'' I {a.k} are real sequences,ark H I for k E N(0).We set some conditions as followsco(I) afk > 0 for k 2 ho 2 0, Zafk = co, i = 1,2,'' 3n -- 1;(II) {gb} is a real sequence and gb 6 Z = {'' 3 --2, --1, 0, 1, 2,' .} fork E N(0), age 2 0, gb 5 k…  相似文献   

4.
We consider the following boundary value problem ill the unbounded donain Liui = fi(x,u, Tu), i = 1, 2,' ! N,x E fl, (1) olLi "i0n Pi(x)t'i = gi(x,u), i = l, 2,',N,x E 0fl, (2) where x = (x i,', x.), u = (u1,' f uN), Th = (T1tti,', TNi'N) and [ n. 1 L, = -- I Z ajk(X)the i0j(X)C], Li,k=1' j=1 J] l Ltti = / K(x,y)ui(y)dy, x E n. jn K(x, y)ui(y)dy, x E n. Q denotes an unbounded dolllain in R", including the exterior of a boullded doinain and 0…  相似文献   

5.
OSCILLATION CRITERIA FOR CERTAIN NONLINEAR DIFFERENCE EQUATIONS   总被引:1,自引:0,他引:1  
1 IntroductionIn a number of recent papers [l-61 oscil1ation of solutions of second ordernonlinear difference equations has been investigated. ln this paper, we studythe oscil1atory behavior of solutions of the second order nonlinear differenceequationA(r.--lAx.--l) p.f(x.) = 0, n = l, 2,'' (1)where the difference operator a is defined by Ax. = xn 1 -- xn) n = 1, 2,' ')and the functions r, p, f are to be specified in the following text. By a solutionof Eq.(1), we mean a real sequence x = …  相似文献   

6.
Let D be a bounded domain in an n-dimensional Euclidean space Rn. Assume that 0 < λ1 ≤λ2 ≤ … ≤ λκ ≤ … are the eigenvalues of the Dirichlet Laplacian operator with any order l{(-△)lu=λu, in D u=(δ)u/(δ)(→n)=…(δ)l-1u/(δ)(→n)l-1=0,on (δ)D.Then we obtain an upper bound of the (k 1)-th eigenvalue λκ 1 in terms of the first k eigenvalues.k∑i=1(λκ 1-λi) ≤ 1/n[4l(n 2l-2)]1/2{k∑i=1(λκ 1-λi)1/2λil-1/l k∑i=1(λκ 1-λi)1/2λ1/li}1/2.This ineguality is independent of the domain D. Furthermore, for any l ≥ 3 the above inequality is better than all the known results. Our rusults are the natural generalization of inequalities corresponding to the case l = 2 considered by Qing-Ming Cheng and Hong-Cang Yang. When l = 1, our inequalities imply a weaker form of Yang inequalities. We aslo reprove an implication claimed by Cheng and Yang.  相似文献   

7.
For integers b and c the generalized central trinomial coefficient Tn(b,c)denotes the coefficient of xnin the expansion of(x2+bx+c)n.Those Tn=Tn(1,1)(n=0,1,2,...)are the usual central trinomial coefficients,and Tn(3,2)coincides with the Delannoy number Dn=n k=0n k n+k k in combinatorics.We investigate congruences involving generalized central trinomial coefficients systematically.Here are some typical results:For each n=1,2,3,...,we have n-1k=0(2k+1)Tk(b,c)2(b2-4c)n-1-k≡0(mod n2)and in particular n2|n-1k=0(2k+1)D2k;if p is an odd prime then p-1k=0T2k≡-1p(mod p)and p-1k=0D2k≡2p(mod p),where(-)denotes the Legendre symbol.We also raise several conjectures some of which involve parameters in the representations of primes by certain binary quadratic forms.  相似文献   

8.
NOTES ON GLAISHER'S CONGRUENCES   总被引:1,自引:0,他引:1  
Let p be an odd prime and let n≥1,k≥0 and r be integers,denote by Bk the kth Bernoulli number,It is proved that(i) If r≥1 is odd and suppose 1≥r+4,then ∑j=1^p-1 1/(np+j)^r=-(2n+1)r(r+1)/2(r+2)Bp-r-2p^2(mod p^3).(ii)If r≥2 is even and suppose p≥r+3, then p-1∑j=1 1/(np+j)^r=r/r+1Bv-r-1p(mod P^2).(iii) p-1∑j=1 1/(np+j)p-2=-(2n+1)p(mod P^2).This result generalizes the Glaisher‘s congruence. As a corollary, a generalization of the Wolsten-holme‘s theorem is obtained.  相似文献   

9.
The asymptotic expansions of the trace of the heat kernel θ(t)=∑^∞v=1^exp(-tλv) for small positive t,where {λv} are the eigenvalues of the negative Laplacian -△n=-∑^ni=1(D/Dx^1)^2 in R^2(n=2 or 3),are studied for a general annular bounded domain Ω with a smooth inner boundary DΩ1 and a smooth outer boundary DΩ2,where a finite number of piecewise smooth Robin boundary conditions(D/Dnj γh)Ф=0 on the components Гj(j= 1,...,m) of (DΩ1 and on the components Гj (j=k 1,…,m) of of DΩ2 are considered such that DΩl=U^kj=lГj and DΩ2= U^m=k 1Гj and where the coefficients γj(j=1,...,m) are piecewise smooth positive functions. Some applications of θ(t) for an ideal gas enclosed in the general annular bounded domain Ω are given. Further results are also obtained.  相似文献   

10.
51. IntroductionIn this paper we investigate the local behavior of nonnegative weak solutions for theequations of non-Newtonian polytropic filtrationac -- div(IDumlp--'Dam) = 0,m(p -- 1) < 1,m > 0,p > l, in D'(flT),u E CI..(0, T; L?o.(n)), urn E Lro.(0, T; WI:)l(fl)), (1.1)where n is an open set of R", N 2 1, 0 < T < ool fiT ~ fix (0, T), and D ~ (k,', e).Equation (1.1) appears in a number of applications to describe the evolution of diffusion.The evolution HLaplacian equationut ~ …  相似文献   

11.
Recently Hong Shaofang$^{[6]}$ has investigated the sums $\sum_{j=1}^{p-1}\limits (np+j)^{{-r}}$ (with an odd prime number $p\geq 5$ and $n , r \in {\bold N}$) by Washington's $p$-adic expansion of these sums as a power series in $n$ where the coefficients are values of $p$-adic $L$-fuctions$^{[12]}$. Herethe author shows how a more general sums $\sum_{j=1}^{p^{l}-1}\limits {(np^{l}+j)}^{{-r}},l \in {\bold N}$, may be studied by elementary methods.  相似文献   

12.
在本文中,我们获得形如[y(t) l∑j=1pj(t)y(σj(t))](n) ∫0q(t,s)f(y(t s))dσ(s)=h(t)的带有振动系数的一类高阶中立型非线性受迫微分方程的振动准则.  相似文献   

13.
张勇 《数学进展》2021,(2):184-194
设b,c为整数,定义广义中心三项式系数Tn(b,c)=[xn](x2+bx+c)n=「n/2」∑k=0(n2k)(2kk)bn-2kck(n∈N={0,1,…}),这里[xn]P(x)表示多项式P(x)中xn项的系数.特别地,中心Delannoy多项式Dn(x)=Tn(2x+1,x2+x)(n ∈ N),中心三项式系数...  相似文献   

14.
For the class Cε={f∈C: En, n≤Z+} where \(\left\{ {\varepsilon _n } \right\}_{n \in Z_ + } \) is a sequence of numbers tending monotonically to zero, we establish the following precise (in the sense of order) bounds for the error of approximation by de la Vallée-Poussin sums: (1) $$c_1 \sum\nolimits_{j = n}^{2\left( {n + l} \right)} {\frac{{\varepsilon _j }}{{l + j - n + 1}}} \leqslant \mathop {\sup }\limits_{f \in C_\varepsilon } \left\| {f - V_{n, l} \left( f \right)} \right\|_C \leqslant c_2 \sum\nolimits_{j = n}^{2\left( {n + l} \right)} {\frac{{\varepsilon _j }}{{l + j - n + 1}}} \left( {n \in N} \right)$$ , where c1 and c2 are constants which do not depend on n orl. This solves the problem posed by S. B. Stechkin at the Conference on Approximation Theory (Bonn, 1976) and permits a unified treatment of many earlier results obtained only for special classes Cε of (differentiable) functions. The result (1) substantially refines the estimate (see [1]) (2) $$\left\| {V_{n, l} \left( f \right) - f} \right\|_C = O\left( {\log {n \mathord{\left/ {\vphantom {n {\left( {l + 1} \right) + 1}}} \right. \kern-\nulldelimiterspace} {\left( {l + 1} \right) + 1}}} \right) E_n \left[ f \right] \left( {n \to \infty } \right)$$ and includes as particular cases the estimates of approximations by Fejér sums (see [2]) and by Fourier sums (see [3]).  相似文献   

15.
强相依高斯序列对高水平超过的弱收敛   总被引:5,自引:2,他引:3  
设{Xn}为标准化非平稳高期序列,rij=cov(Xi,Xj),Nn为{Xn}对水平un=x/an bn的超过数形成的点过程。当rijlog(j-i)→r∈(0,∞),(j-i→ ∞),且n→∞时,点过程Nn依分布收敛到Cox-过程。  相似文献   

16.
张霞  张建华 《数学学报》2020,(3):221-228
设u=Tri(A,M,B)是三角代数,{φn}n∈N:u→u是一列线性映射.本文利用代数分解的方法,证明了如果对任意U,V∈u且U。V=P为标准幂等元,有φn([U,V]ξ)=Σi+j=n(φi(U)φj(V)-ξφi(V)φj(U))(ξ≠±1),则{φn}n∈N是一个高阶导子,其中φ0=id为恒等映射,UoV=UV+VU为Jordan积,[U,V]ξ=UV-ξVU为ξ-Lie积.  相似文献   

17.
We show a purity property for the rigid cohomology groups associated to exponential sums on a smooth and affine variety. For this purpose, we compare these groups with the p-adic Banach spaces of Dwork's theory constructed by Adolphson and Sperber [1].  相似文献   

18.
We completely describe the Siegel discs and attractors for the p-adic dynamical system f(x) = x 2n+1 + axn+1 on the space of complex p-adic numbers.  相似文献   

19.
一类中立型高维周期微分系统的周期解   总被引:10,自引:1,他引:9  
贺明科 《数学学报》1999,42(2):271-280
本文考虑中立型高维周期系统:其中(L,x)∈R×R~n,A(t,x)为连续函数矩阵,x_t∈C([-γ,0],R~n),x_t(θ)=x(t十θ),θ∈[-r,0],记C=C([-r,0],R~n),f:R×C→R~n连续,且A(t+T,X)=A(t,x),T,r>c∈R,本文用不动点方法研究此系统,得到了其周期解存在的充分性条件,所得结果推广、改进了文[1-3]中相应结论.  相似文献   

20.
张岩  李云章 《数学学报》2019,62(1):1-12
p-进制MRA与GMRA是构造L~2(R_+)中小波框架的重要工具. L~2(R+)中嵌套子空间序列交集为{0},并集为L~2(R_+)是其构成p-进制MRA与GMRA的基本要求.本文研究单个生成元Walsh p-进制平移不变子空间伸缩的交与并,证明了:对任意单个生成元Walsh p-进制平移不变子空间,其p-进制伸缩的交是{0};若生成元分为Walsh p-细分函数,则其p-进制伸缩的并是L~2(R_+)中一个Walshp-进制约化子空间.特别地,其伸缩构成L~2(R_+)中p-进制GMRA当且仅当∪_(j∈z)p~j supp(■φ)=R+,其中■为定义在L~2(R_+)上的Walsh p-进制傅里叶变换.值得注意的是:形式上,我们的结果类似于通常L~2(R)的情形,然而其证明不是平凡的.这是因为定义在R_+上的p-进制加法"⊕"不同于定义在R上的通常加法"+".  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号