基于B样条构造高精度拟插值

给出了在非均匀节点情形下用任意k阶B样条作为基函数构造具有高次局部多项式再生性质拟插值的一种方法,并用此方法构造出在无限区间R上具有k-1次多项式再生和k阶收敛阶性质的高精度拟插值(㏑f)(x).进一步地,利用B样条的相关性质由(㏑f)(x)构造出有限区间[a,b]上的高精度拟插值(㏑f)(x).作为数值例子,最后用4阶B样条构造的高精度拟插值(㏑f)(x)逼近一些典型函数以说明其确实具有高精度逼近性质.     

基于双二次B样条的拟插值算子的构造

对数据点{(xi,yj),f(xi,yj)},(i=0,1,…,n;j=0,1,…,m),应用双二次B样条基函数构造了一种双变量拟插值算子(Lf)(x,y),证明了算子(Lf)(x,y)具有二次多项式再生性,并给出了其逼近误差,最后通过数值模拟说明了该算子的可行性.     

一种针对线性数据的高精度拟插值算子

插值具有很高的逼近阶但是需求解线性方程组.拟插值精度较低,但不需求解线性方程组就能直接得到逼近函数.基于径向基Multiquadric(MQ)函数和Inverse multiquadric(IMQ)函数,构造新的高精度拟插值算子L*f(x),并且证明该算子的精度和线性多项式再生性.并且通过数值算例验证该算子具有良好的逼近精度.     

一种高阶有理H-F插值逼近算子(Ⅰ)

本文构造出一种高阶有理Hermite-Fejer插值算子,不仅去掉了G.Grūnwald的插值多项式算子中收敛性条件——插值结点组强正规,我们还得出该算子的逼近度。     

Bernstein算子和Grünwald算子的线性组合

以第一类n阶Chebyshev多项式的零点作为插值节点 , 通过Bernstein算子和Grünwald算子的线性组合构造一个新算子G_n(f;x). 如果f(x)∈C^j_{［-1,1］(0≤j≤9), 则Gn(f;x)在区间 ［-1,1］上一致收敛于f(x)∈C^j［-1,1］(0≤j≤9), 并且其收敛 阶达到最佳, 饱和阶为1/n¹⁰.}     

两个切触有理插值逼近算子

本文构造了两个切触有理插值逼近算子Hn(f;x)和Gn(f;x)。它们分别基于Hermite-Fejer插值多项式Hn(f;x)和Grunwald插值多项式Gn(f;x)。主要证明了当f∈c[-1,1]时,有|Hn(f;x)-f(x)|=0(1)Wr(1/n)(n≥2) |Gn(f;x)-f(x)|=0(1)Wr(1/n)(n≥2)其中Wr(δ)是f(x)的连续模。显然它们的逼近阶优于Hn(f;x)和Gn(f;x)的逼近阶[1]。     

关于第一类有理插值逼近算子的研究

本文在文献[1]的基础上,以第一类Chebyshev多项式Tn(x)的零点为基点,构造了第一类有现插值算子R_n~(s)(f;x),本文得到了SUP f∈H_ω|R_n~(s)(f;x)-f(x)|在S≥1时的上、下界估计,将[1]中定理2作了进一步的推广;并证明了当0相似文献   

Bernstein算子和Grünwald算子的线性组合

以第一类n阶Chebyshev多项式的零点作为插值节点 ， 通过Bernstein算子和Grünwald算子的线性组合构造一个新算子G_n(f;x). 如果f(x)∈C^j_{［-1,1］(0≤j≤9), 则Gn(f;x)在区间 ［-1,1］上一致收敛于f(x)∈C^j［-1,1］(0≤j≤9), 并且其收敛 阶达到最佳, 饱和阶为1/n¹⁰.}     

三角插值多项式的线性组合

鉴于Lagrange插值多项式并非对任何连续函数都能一致收敛,以x(n)k=2k 1/2n 1π,k=0,l,…,2H作为插值节点,将几个算子进行线性组合,构造了两个新的算子Un(f;x)和Un(f;x),使它们的最高收敛阶要优于算子An(f;x),Bn(f;x),Cn(f;x)。     

无穷区间上的高阶奇型微分算子的自共轭域的辛几何刻画

从辛几何的角度研究定义在无穷区间上高阶奇型对称微分算子的辛结构,利用最大与最小算子域构造了一个辛空间,用辛空间中的线性流形来刻画定义在无穷区间上高阶奇型对称微分算子的自共轭扩张问题.给出了与微分算子自共轭域相联系的相应的Lagrangian子流形的描述和分类情况,等价于对微分算子l(y)的自共轭域进行描述.     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Design and analysis of generic LBS application developing platform

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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