差商与牛顿插值多项式的承袭性算法

根据函数的差商的对称性，导出了差商的另一个更具数学意义的表达形式，即ｆ的任意阶差商均可表示为某个函数的函数值之差与自变量之差的商，由此导出了ｆ的ｋ＋１阶差商ｆ「ｘ０，ｘ１，．．．，ｘｋ，ｔ」与ｋ阶差商ｆ「ｘ０，ｘ１，．．．，ｘｋ－１，ｔ」之间的简单的递推关系，进而对于在插值基点ｘ０，ｘ１，．．．，ｘｎ中的任意位置增加或删除一个插值基点的诸问题找到了具有承袭性的算法。     

关于一些Hermite-Fejer算子逼近度的注记

本文研究以Jacobi多项式的J_n(x)=sin(2n+1)/2θ/sinθ/2(x=cosθ,0≤θ≤π)的零点为基点的Hermite-Fejer插值过程H_(2n-1)(f,x).对于Lipα(0<α<1)类中函数,改进了[1]的结果:得到了H_(2n-1)(f,x)逼近有界变差函数的阶估计. 设函数f(x)∈C〔-1,1〕,x=cosθ(0≤θ≤π),J_n(x)是n阶Jacobi多项式,x_k=x_k~(n)=cosθk=cos(2kπ)/(2n+1)(k=1,2,…,n)是J_n(x)的零点,以{x_1,x_2,…,x_n}为基点的Hermite-Fejer插值算子是(见文〔1〕(4))     

关于k 1类亏度为k的2k次插值样条

对任意自然数k,本文提出了k 1类亏度为k的2k次插值样条。较完整地讨论了它们的存在唯一性及对已知函数的逼近度,并论及了其中几类插值样条所具有的某种交分性质。文[1]、[2]中论及的二、四次插值样条均为本文的特例。最后我们指出了一类插值样条在数值积分中的应用。插值问题的提法及其存在唯一性给定区闻[a,b]上的一个分划Δ:a=x_1相似文献   

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.     

Lagrange 插值多项式的线性组合

鉴于 L agrange插值多项式并非对任何的连续函数都能一致收敛 ,本文以 ( 1-x) Wn( x)的零点作为插值节点 ,对 L agrange插值多项式中的被插值函数进行线性组合 (也称函数平均 ) ,构造了算子 An,r( f;x) ,它对于有任意阶导数的连续函数 f ( x )∈ Cl[-1,1] ,( 0≤ l≤ r)都一致收敛 ,收敛阶为 |An,r( f ;x ) -f ( x ) |=O En( f ) 1nl ω( f (l) ,1n) 1nl 1且收敛阶达到了最佳 .( r是奇自然数 )     

分数阶常微分方程多点边值问题的上下解方法

本文应用上下解方法研究了如下分数阶常微分方程多点边值问题{x~((δ))(t)=f(t,x(t)),t∈[a,b],a0,x(a)+m∑k=1a_kx(t_k)=c解的存在性,其中f:[a,b]×R→R是L~1-Carathéodory函数,δ∈(0,1],c∈R,t_k(k=1,2,…,m)为满足at_1t_2…t_mb,a_k0以及1+m∑k=1a_k0的常数.     

函数Riemann和式的类Taylor级数展开式

如果一元解析函数f(x)无f限阶可导,其Taylor级数展开式f(x)=f(0)+f'(0)x+f″(0)/2!x~2+…+f~((k))(0)/k!x~k+…=∞∑k=0f~((k))(0)/k!x~k.本文讨论将一元无限阶可导函数f(x)在区间[a,b]上的Riemann和式b-a/nn∑k=1f(a+k/n(b-a))展开成1/n的级数:b-a/nn∑k=1f(a+k/n(b-a))=A_0+A_1·1/n+A_2/2!·(1/n)~2+···+A_i/i!·(1/n)~i+···可以看到,这个展开式在形式上与函数的Taylor级数展开式非常相似.     

一类S.N.Bernstein型插值过程的最佳一致逼近

进一步研究了第三型S.N.Bernstein插值过程，用一种全新的方法构造了一个算子An(f;r,x)，它对于有任意阶连续导数的f(x)∈C[-1,1]^1,(0≤l≤r-1)都一致收敛，并且得到了算子An(f;r,x)的最佳收敛阶。     

分数阶积分微分方程解的存在性和唯一性

研究如下的Caputo分数阶微分积分方程初值问题:{(cDαa+g)(x)=f(x,cDβa+g(x))∫+xaK(x,t,cDβa+g(t))dt,g(k)(a)=η(k),n-1<β<α相似文献   

关于 Hermite 插值多项式同时逼近函数及其导数

设 P(α,β,n)(x)(α,β>-1)是 n 阶 Jacobi 多项式,本文引入以(1+x)p(α,β,n)(x)的零点集{x_k}_(k=0)~n 作为基点的 Hermitc 插值 H_(2n+1)(f,x)。我们研究用 H_(2n+1)(f,x)同时逼近函数及其导数的问题。     

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.     

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     

Call for Papers

<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