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1.
本文研究如下具有色散的反应扩散方程组ut=DΔu-γu+Σnj=1Bj(x)uxj+f(u),x∈Ω,t>0,u(x,t)=0,x∈Ω,t>0,u(x,0)=u0(x),x∈Ω.(1)其中Ω是Rn中的有界开集且具有光滑的边界Ω,u=(u1,…...  相似文献   

2.
具有强非线性源的非牛顿多方渗流方程的局部可解性   总被引:1,自引:0,他引:1  
研究如下第一边值问题ut=div(|Dum|p-2Dum)+f(x,u)(x,t)∈QT=Ω×(0,T)u(x,t)=0(x,t)∈Ω×(0,T)u(x,0)=u0≥0x∈Ω{的可解性,得到了局部可解定理.  相似文献   

3.
考虑下面高阶摄动方程解u(x,t)的LpLp′估计:tu+(-Δ)mu+V(x)u=0,u(x,0)=0,ut(x,0)=f(x),{x∈Rn,n>3m.假设势函数V(x)和初值f(x)具紧支集,V(x)是小势,则上面问题的解满足‖u(·,t)‖p′≤ct-d‖f‖p,t>0,这里m≥1,d=nm(1p-1p′)=1,1p+1p′=1,m2n≤1p-12<mn.  相似文献   

4.
获得了具偏差变元非线性双典型方程2ut2+p(x,t)u(x,t)+∑ki=1pi(x,t)fi(u(x,τi(t))=a(t)△u+∑mj=1aj(t)△u(x,σj(t)),(x,t)∈Ω×(0,∞)≡G,的解振动的充分条件.其中Ω是Rn中具逐片光滑边界的有界区域.  相似文献   

5.
关于山路定理的应用的一个注记   总被引:2,自引:0,他引:2  
研究了Dirichlet问题-Δu(x)=f(x,u),x∈Ω,u∈H10(Ω),其中Ω是RN(N≥1)中的有界光滑区域.在一定条件下,得到了下列结论:(i)当λ1<l<+∞且l≠λj,j≥2时,该问题存在正解;(i)当l=λj,j≥1,且limt→∞[f(x,t)t-2F(x,t)]=+∞时,存在非退化解;(ii)当l<λ1时,没有正解.  相似文献   

6.
一类可以精确确定blow-up时间的blow-up问题牛健人(中国民航飞行学院)崔泽健(四川师范学院)记Ω=(-L,L),Qt=Ω×(0,t],本文讨论如下问题:(I)ut=(um)xx+uαt>0,-L<x<L,ux(±L,t)=0,t>0,u(x...  相似文献   

7.
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   

8.
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   

9.
Bernstein-Sheffer算子在CΩ空间上的逼近等价定理   总被引:1,自引:0,他引:1  
研究了 Bernsteinsheffer 算子在 CΩ空间上的逼近性质,建立了逼近等价定理:  1)当 h> 0 时, B Hn 是[0,1]到自身的正线性算子,则 f∈ D2= {f|‖ B Hn (f)- f‖Ω= O(n- α2 ),f ∈ CΩ,等价 K(f ,t)= O(tα2 ,|0< α< 2);  2)对 0< α< 2,f∈ CΩ,对下命题等价  i)f∈ Dα= {f|‖ B Hn (f)- f‖Ω= Ο(n- α/2)};  ii)对 L∈ C0 ,有 | L(f)| ≤ M f (| L|(Ω))1- α/2(∫10| L(k(·,u))| Ω(u)φ(u) du)α/2.  相似文献   

10.
研究了与等周不等式有关的约束极小问题:It=infQ(u+tψ)=1,u∈H10(Ω,R3)∫Ω|u|2dxdy,其中,Ω为R2中的有界区域,Q(v)=∫Ωv(vx∧vy)dxdy.证明了如下结论:1)对于ψ∈H10(Ω,R3),若ψx∧ψy0,且ψ∈C1,10(Ω,R3),则It→S(当t→0时);2)设ut是It的极小可达函数,则存在某一x0∈Ω,使得|ut|2Sδx0(当t→0时)(在测度意义下),这里S=inf∫R2|u|2dxdyu∈H10(R2,R3),Q(u)=1{}  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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