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1.
多元cardinal样条空间的极值性质   总被引:1,自引:1,他引:0  
通过研究多元cardinal样条函数插植的逼近性质,给出了各向异性Sobolev光滑函数类W^r∞(R^d)在L∞(R^d)尺度下最佳逼近的弱渐近估计,这个结果表明,多元cardinal样条函数空间是各向异性Sobolev光滑类W^r∞(R^d)在L∞(R^d)尺度下关于无穷维Kolmogorov宽度的弱渐近极子空间,也表明多元cardinal样条函数插值是实现线性宽度的最优算子。  相似文献   

2.
考察了基于一个函数类的Cardinal样条插值。被插函数属于Sobolev函数类。并得到了Lp(R^d)尺度下的误差估计。  相似文献   

3.
一类半线性波动方程的低正则性估计   总被引:1,自引:1,他引:0  
对形如uu-△u-u^k(Du)^a(x∈R^3,k∈Z^+,l+|a|=2)的半线性波动方程在三维空间中的Sobolev指数进行了研究,用较简单的方法得到了与KlainermanS.和MachedomM.(Arch Rat Mech Anal,1992,86(5):369)相同的结果,即Sobolev指数为2。  相似文献   

4.
一类非线性退缩椭圆组弱解梯度的Lp-估记   总被引:1,自引:0,他引:1  
利用Muckenhoupt提出的A2类函数的性质和带A2类权函数Sobolev空间H^1(Ω,R^N,λ)的嵌入不等式,对满足控制增长和自然增长条件下的非线性退缩椭圆组,建立了弱解梯度的L^p-估计,只要λ^2(x)∈A2,就可以将Giaquinta关于一致椭圆组的有关结果推广到爱缩椭圆组。  相似文献   

5.
对于给定的函数f∈W′M[-π,π]d,Mbasker和Micheli已构造出具体的神经网络逼近Sobolev类函数及其导数并给出逼近阶的估计。但对于给定的函数φ∈W′M(R′)并没有考虑。文章通过一个定理和Mbasker的一个结果,对给定的函数φ∈W′M(R′)构造出具体的神经网络逼近Sobolev类函数及其导数并给出逼近阶的估计。  相似文献   

6.
确定了r阶缓增样条类的平均维数的精确估计,并证明了缓增样条函数类是Soborev类W2^r(R)在L2(R)尺度下的一个最优子空间。  相似文献   

7.
研究高维空间中半线性波动方程uu-△u=u^k(x∈R^n,k∈Z^+,k≥2)的低正则性,得到了其Sobolev指数为n/2-1/(k-1)。  相似文献   

8.
在外力f=f(x)∈L^2(Ω,R^d),初值v0∈J0(Ω,R^d)(d=2,3)的情形以(dV^n/dζ,ω^k)+v(vx^n,ωx^k)+b(v^n,v^n,ω^k)=(f,ω^k)(k=1,…,n),v^n(0)=(v0,ω^1)ω^1+…+(v0,ω^n)ω^n定义的复的ГaЛepknH近似证明了二维Navier-Stokes方程的弱解和三维Navier-Stokes方程的由ГaЛep  相似文献   

9.
从Sobolev型空间了发,构造了更广泛的齐次群上的Sobolev型空间V^m,p,基于W^m,p(G)=W^n,p,0(G0这一偏微分方程中的重要关系式,建立了齐次群G上的关系式V^m,p,0(G)=Vm,p(G)并给出了严格证明。  相似文献   

10.
研究了由线性微分算子Pr(D)=D^σП(D^2-tj^2I)在3处不同的边界的边界条件下确定的Sobolev类Ωp^r,Ωp^4,Ωp^2l+1在L^q尺度下的宽度计算问题,得到了在1〈q〈p〈∞条件下Kolmogorov,Gelfand和线性宽度的精确值,并构造出相应的极子空间及最优线性算子:在1〈p≤q〈≤∞条件下得到了Bemstein宽度的精确值,并构造出相应的极子空间。  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.
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   

18.
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   

19.
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   

20.
<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   

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