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1.
对于周期为2π并且r阶导数为φ-有界变差函数,我们证明了:│Sn(f,x)-f(x)-sinr/2π/πn^r(fR^(r)(x)-fL^(r)(x))│≤3/n^r+1Σ↑n↓k=1Vφ(ψx,[0,π/k])+2│sinr/2π│/πn^r+1│fR^(r)(x)-(fL^(r)(x)│,其中f∈φBV∩Vr。  相似文献   

2.
本文在空间C(「ε0,T」,L^p)∩C^1(ε0,T「,L^内考虑边值问题 {δu/δt-1/t^αu=│u│^r-1u t〉ε0〉0 (1) limu t ↓ε0(t,x)=ψ(x) x∈R^n(2)其中γ〉1,p≥1,ε0是一个固定的正数。在L^p内ψ(x)≥0且不恒为零,α〉0,我们给出了问题(1)(2)有正解的一个必要条件,并研究了正解的不存在性。  相似文献   

3.
运用G Sansone定理和旋转向量场理论,研究奇次微分系统x=-y(1-ax)(1-bx)+δx-lx^2n+1,y=x(1-ax)(1-bx)的极限环的存在唯一性。证明了:当δl≤0时不存在极限环,当δl〉0,│δ│〈│l│/max{a^2n,b^2n}时存在唯一的极限环;当δl〉0,│δ│≥│l│/max}a^2n,b^2n},时不存在极限环。  相似文献   

4.
本文得到以下形式的Bernstein不等式:Pn(D)=∏^ks=1(D^2+2αsD+a^2s+β^2s)∏^n-2kj=1(D-λj),D=d/dx,λj,αs,βs是实数,βs〉0,β=maxβs,如果σ〉4β,则对任一指数型整函数f(x)∈Bσ,有‖Pn,(D)f(X)‖c≤│Pn(iσ)│sup│f(x)│。  相似文献   

5.
亚纯函数与亚纯代数体函数的Julia点   总被引:1,自引:0,他引:1  
讨论定义于│z│〈1内的v-值亚纯代数体函数w=W(z)(v=1时,W(z)就是亚纯函数)。证明了定理 如果W(z)满足条件lim↑-↓r→1T(r)/log1/1-r=∞则存在一个Julia点e^iθ0(0≤θ0≤2π),使得对于任意给定的数δ(0〈δ〈π/2),在扇形域Δ(θ0,δ)={z││argz-θ0│〈δ,│z│〈1}内,对任何复数值a,总有lim↑-↓r→1n(r,(θ0,δ),a)  相似文献   

6.
从城市系统的一般方程出发,导出城市人口密度衰减的分形模型(ρ(r)∞r^D-d),进而提出城市人口空间分布的Weibull型公式(P(r)/P0=1-exp」-(r/rp)^D「),基此将传统的城市人口密度衰减模型由指数型(e^-r/r0)和Gauss型(e^-(r/r0)^2)推广到一般形式(e^-r/r0)^δ,并揭示了它与分形模型的内在关系。  相似文献   

7.
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   

8.
本利用上下解方法研究了一类Volterra-hammerstein型积分微分方程非线性边值问题{(│u'│^p-2u')'=f(t,u,T1u,T2u,u')(p〉1) L(u(0),u'(0))=0 R(u(1),u'(1))=0 [Tiu](t)=ψi(t)+∫o^tKi(t,s)u(s)ds (i=1,2)给出了解的存在性定理。  相似文献   

9.
本文讨论了问题Pm│res sor,pj=1│Cmax的解法,并且证明了基本例子(基本向量)数不大于(0+1)^(r+1)^s-1,给出了求基本向量的算法。  相似文献   

10.
带有p-凹凸非线性项的p-Laplace方程的无穷多解的存在性   总被引:2,自引:1,他引:1  
证明了当λ〉0或μ〉0时p-LaplaceDirichlet问题,-div(│↓△u│^p-2↓△u)=λ│u│^q-2u+μ│u│^a-2u,u∈W^1,p0(Ω),无穷多解的存在性,其中Ω是R^N中有界开集,1〈q〈p〈α〈p。  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.
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   

19.
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   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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