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为了改善Lagrange插播算子的一致收敛性并提高算子最佳收敛阶,我们以一类Ja cobi多项式的零点作为插值结点,通过对插值结点处函数值的线性组合,构造了一类线性插值算子,给出了该类算子的最佳收敛阶定理;进而研究了此类算子的导数逼近问题,利用对算子进行分项估计的方法,不仅证明了该算子的导数一致收敛于具有连续导数的函数,而且给出了算子的一阶导数逼近函数导数的最佳收敛阶. 相似文献
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本文给出一类离散指数型线性积分修正插值算子,而且借助Cauchy主值积分给出了其在L_p(-∞,∞)中的收敛速度。 相似文献
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修正后的Lagrange插值多项式的逼近阶 总被引:2,自引:2,他引:0
袁学刚 《烟台大学学报(自然科学与工程版)》2000,13(1):4-7
对Lagrange 插值多项式进行了修正,构造了一个算子,它对于在区间[ - 1 ,1] 上有任意阶连续导数的函数都一致收敛,并且收敛阶达到了最佳,而且算子的最高收敛阶为1/ nr . 相似文献
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通过对Fourier部分和做适当的构造,可得到一致收敛的求和算子,而求和因子法是一种行之有效的方法被广泛使用.但是一般文献中利用的求和因子法构造的算子在使用上具有很强的约束性.基于求和因子法和Fourier级数与等距结点上的三角插值多项式的相似性,对一些不能一致收敛的一元三角插值算子进行新的相关构造,得出一类一致收敛的一元Fourier部分和算子和离散的一元Fourier部分和算子,给出了它们收敛阶的估计,得到该类算子的饱和阶.并且推广了一些文献中的结论,并且本文给出的方法更具有一般性. 相似文献
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构造了不依赖于结点组的更广的一类二元Fourier插值算子和二元离散的Fourier插值算子,估计了两类算子的收敛阶,并且证明了对于二元连续周期函数类来讲,该收敛阶是最优的.更进一步讨论了这两类算子的饱和问题,得到了饱和阶的估计.在收敛阶和饱和阶的度量上,论文结果与以往文献中的结果是一致的. 相似文献
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关于一类广义Bernstein多项式的逼近 总被引:2,自引:0,他引:2
构造一类广义Bernstein算子,利用Korovkin定理得到了该算子及其导数在连续函数空间收敛的充要条件,并借助光滑模和Ditzian-Totik光滑模给出了它们逼近阶的估计. 相似文献
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构造了一类基于等距结点组上的二元三角插值多项式算子,使得该算子在全平面上一致收敛到每个以2π为周期的二元连续函数,并且对具有任意阶连续偏导数的函数全体的逼近具有最佳收敛阶. 相似文献
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一类三角求和算子的一致收敛性 总被引:2,自引:1,他引:1
由于Lagrange插值算子并非对任意的连续函数都一致收敛,为了改善其收敛性,我们通过对插值基函数,引入中心差分算法基于等距结点组构造了一类三角求和算子;证明了该算子在全实轴上一致收敛于任意以2π为周期的连续函数,得到了算子的最佳逼近阶以及最高收敛阶;另一方面,本文构造的算子也可以看作是Bernstein和Kis两人构造的算子的线性组合,而在收敛性方面,本文的算子明显优于两种已有的算子.最后通过数值算例和例图对这些算子的逼近性质进行了比较. 相似文献
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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
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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
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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
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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
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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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《上海师范大学学报(自然科学版)》2014,(5):550
<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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《吉林大学学报(理学版)》2014,(5):1105
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has 相似文献