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1.
本文讨论带非线性边界条件的抛物型方程组ut = Δu m ,vt = Δvm ,x ∈Ω,t > 0 ,un = upvq ,vn = urvs ,x ∈Ω,t > 0 ,u( x ,0) = u0( x) ≥δ> 0 ,v( x ,0) = v0( x) ≥δ> 0 ,x ∈珚Ω. ( Ⅰ)解的整体存在性。其中m 、p 、q 、r 、s 均为正数,Ω I R N 是有界光滑区域。δ> 0 可以充分小。利用熟知的上、下解方法,得到关于问题( Ⅰ) 整体解存在的二个充分条件。  相似文献   

2.
利用禁值型论证法,在某些较一般的条件下,建立了形如-Δu=f(x,u),x∈Ω,u=0,x∈Ω{的Dirichlet问题非负解的存在性,Ω是Rn(n≥1)中的有界域,边界Ω适当光滑  相似文献   

3.
考虑下列带有摄动位势波动方程解的Lp估计tu-Δu+V(x)u=0,u(x,0)=0,tu(x,0)=f(x),{(x∈Rn,n≥3)其中f(x)∈Lp(Rn),|1p-12|≤1n-1.如果V(x)是紧支集的小势,本文证明了以上问题的解和非摄动问题(V(x)≡0)的解具有同样的Lp估计:u(t,)P≤Ctfp,t>0.  相似文献   

4.
本文讨论二阶复合型方程组(CE2):10012t2+100λ/R22x21+0(λ-k2)/k2(λ-1)/k02x1x2+λ0012x22u1u2=0(0<k<1,λ<0)得到了该方程组有解的必要条件,并由此知道该方程组的Cauchy问题是不适定的,转而讨论问题(D2),证明了问题(D2)是可解的,并给出了解的表达式  相似文献   

5.
利用解的先验估计方法,对Dirichlet问题-2u+k(x)uα=λf,u>0,x∈Ω,u|Ω=0{在k(x)和f更一般的情况下,建立了该问题的古典解不存在的准则  相似文献   

6.
一般二维非线性奇异问题的有限元方法   总被引:1,自引:1,他引:1  
考虑如下一般二维非线性奇异边值问题Lpu=-1p(x)x(p(x)ux)-2uy2=f(x,y,u(x,y)),(x,y)∈Ω,u|Γ=0,ux|Γ0=0{的有限元方法.给出相应问题广义解的存在唯一性及先验估计,并使用对称有限元法,证明有限元解的收敛性,给出了加权L2模和加权L∞模误差估计  相似文献   

7.
讨论下面方程的Cauchy问题:utt-Δu=|ut(x,t)|p,t≥0,x∈R3,u(x,0)=εf(x),ut(x,0)=εg(x),x∈R3,这里Δ=∑3i=12x2i,常数p>1,ε是正参数,H.Takamura(ComminPDE,1992,17(1&2):189)猜侧上面的Cauchy问题在p>2时是否对充分小的初值存在整体C2解.本文将在f(x),g(x)满足一定条件下在p>3时部分回答这个问题  相似文献   

8.
本文讨论齐次波动方程:utt-Δu=0具缓减初值f(x),g(x)时Dαxu的增长问题,其中u(x,0)=f(x),ut(x,0)=g(x).  相似文献   

9.
无界域上Schroedinger型方程的整体吸引子   总被引:1,自引:0,他引:1  
本文证明了Schrodinger型方程δtu=(k+iβ)Δu-│u│^ρu-λu-g,u(x,0)=u0。其中u=u(x,t),g=g(x),k〉0,ρ〉0,λ〉0,x∈R^n在加权Sobolev空间中强和弱吸引子的存在性,并对吸引子的分形维数也给出了估计。  相似文献   

10.
关于Cauchy问题解爆破的一个条件曹镇潮(厦门大学数学系厦门361005)在RN×R+(N2)中考虑非线性双曲型方程的Cauchy问题ut-△u=|u|p-1u,(x,t)∈RN×(0,T)u(x,0)=g(x),x∈RNut(x,0)=h(x)...  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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