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1.
Wolstenholme定理的推广   总被引:1,自引:0,他引:1  
本文将数论中的Wolstenholme定理推广为定理设素数p>3,v,t_0,t_k∈Z(1≤k≤p-1),并且0≤2v<p-3,(t_0,p)=1及t_1+t_(p-1)=t_2+以s表示满足(modp ̄2)的整数,那么,  相似文献   

2.
用上、下解方法研究非线性差分方程初值问题:△uk+f(k,uk)=0,k=1,…,n;u_0=0,其中△uk=uk-uk-1,给出下解v不超过上解w的一个充分条件:当f(k,u)关于u不减时,有v≤w.用Brouwer不动点定理以及修正初值问题的技巧,建立了解的存在定理:在f(k,u)关于u连续的条件下,对给定的下解v与上解w;v≤w,初值问题存在解u满足v≤n≤w。  相似文献   

3.
高阶发展方程的两类显式格式的稳定性分析   总被引:1,自引:2,他引:1  
对高阶发展方程Эu/Эt=aЭ^2k+1u/Эx^2k+1给出了两类带参数a的三层显式差分格式,其截断误差均为O(ι+h)。稳定性分析指出:当k为偶数时,它们无条件不稳定;当k为奇数时,稳定条件为│R│≤f(k,a)是a(0≤a≤10)的上升函数,但为k的下降函数。例如,当k=1时,f(1,3)=0.987123,f(1,10)=2.150690;当k=3时,f(3,3)=0.109153,f(3  相似文献   

4.
本文考虑定常的奇异摄动系统(1.1)dx/dt=f(x,y,ε),εdy/dt=g(x,y,ε)及其退化 系统(1.2)dx/dt=f(x,y,0),0=g(x,y,0).假设系统(1.2)有一个非常数的概周期解(1.3) x=u(t),u=V(t).当系统(1.2)关于(1.3)的第一变分方程系恰具有一个广义零特征指 数时,我们在适当的条件下证明了对充分小的ε,系统(1.1)有唯一的概周期解x=x(t,ε), y=y(t,ε)使得当ε→o时,对一切t有||x(t,ε)-u(t)||+||y(t,ε)-v(t)||→0。 在证明中,我们首先推广了法坐标变换,进而建立指数型二分法,然后把问题化为非定常系统的 相应问题,从而利用K.W.Chang[5]的结果加以解决.  相似文献   

5.
1 一维守恒双曲型标量方程的初边值问题解法讨论一维标量守恒双曲型方程 ut+f(u)x=0(1)的纯初值问题 u(x,0)=φ1(x)(-∞<x<∞)(2)及初边值问题 u(x,0)=φ1(x),(0≤x<∞) u(0,t)=φ2(t)(0≤t<∞)(3)并得到如下结果:1)问题(1),(2)当1+f″φ1′t≠0时的隐式解为 u(x,t)=φ1(x-f′(u(x,t))t)(4)2)问题(1),(3)当1+φ′1f″t≠0,1-φ2′xf″/(f′)2≠0时的解为 u(x,t)=φ1(x-f′…  相似文献   

6.
记B是由1,2,…,n的循环排列组成的集合,A_3(n)=maxmin(a_(i+1)+a_(i+2)+a_(i+3)),其中i=0,1,2,….n-1,a_(n+1)=a_1,a_(n+2)=a_2;ai取1.2,…,n中的任意值,i=1,2,…,n.本文讨论了A_3(n)的上界:除n=3,5.6外,当3|n-1时,A3(n)≤ ;当3|n时,A3(n)≤ ;当3|n+1时.A_3(n)≤.  相似文献   

7.
关于Hanulton方程组的次调和解的存在性,已有的结果都不同程度地要求H(t,u)关于u具有一定的增长性,这种增长性对于t还是一致地成立 ̄[1],[2],[3],[4]。本文去掉了这种增长性关于t是一致的要求,在软弱的条件(其中β(t)是R上的非负T周期函数且β∈L ̄2[0,T],δ>0)下,利用对偶泛函的极小比方法得到了方程组存在一列KT周期解u_k,使得当k→∞时,‖u_k‖_∞→∞,并且u_k的极小周期T_k→∞。  相似文献   

8.
设p是一个给定的素数,f(x_1…,x_k)∈z_p[x_1…,x_k],且f(x_1,…,x_k)是一个d(d>0)次强非退化型,这里Z_p代表p-adic整数环,设c_n是模p ̄n剩余类环Z/p ̄nZ上方程f=0的解的个数,本文给出c_n的一个直接公式,这是Goldman有关结果的改进。还证明了d≥k时,c_R≡0(modp ̄(n-1)(k-1).  相似文献   

9.
四阶泛函微分方程边值问题的上下解方法   总被引:2,自引:0,他引:2  
利用和发展微分方程边值问题上下解方法,讨论了四阶泛函数分方程边值问题u^(4)(t)=f(t,u(w(t))m,u^″(t),0〈t〈1;u(s)=ψ(s),s∈「-τ,0,ψ(0)=0,u(1)=u″(0)=u″(1)=0 解的存在性定理。  相似文献   

10.
本文讨论了初值问题{δu/δt-1/tΔu=u^r t〉ε0〉0 x≤R^n(0.1) u(ε0,x)=(x) x∈R^n(0.2)其中γ≥1,ψ(x)连续有界,且ψ(x)≥0但不恒为零。我们证明了当1/γ-1≥n/2时,初值问题(0.1)(0.2)的非负解必在有限时间blow-up。即问题(0.1)(0.2)在1/γ-1≥n/2时没有非负的整体解。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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