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1.
提高算子的逼近速度,采用了使算子保持函数x2不变的方法对经典的Baskakov算子进行了修正并研究了修正后算子的逼近问题,得到了该算子的局部逼近和点态逼近定理.研究结果表明:修正后的Baskakov算子不仅保持了函数x2不变,而且比修正前的Baskakov算子有更好的逼近性.该结论对于此领域其它相关问题的研究也具有一定的启发意义. 相似文献
2.
高义 《宝鸡文理学院学报(自然科学版)》2010,30(2):13-16
目的 研究二元非乘积型广义Baskakov算子的逼近逆定理.方法 利用多元分解技巧.结果 在已有关于二元非乘积型广义Baskakov算子逼近正定理的基础上,给出该算子在局部意义下的逼近逆定理.结论 该结果刻画了其在经典空间中局部意义下的逼近特征. 相似文献
3.
韩领兄 《华东师范大学学报(自然科学版)》2018,(2)
为了得到更快的逼近速度,人们开始研究算子的拟中插式的逼近性质.在Orlicz空间中讨论左拟中插式Gamma算子的逼近性质,利用了Ditzian-Totik模与K-泛函的等价性、Holder不等式、Cauchy-Schwarz不等式和Laguerre多项式等等工具得到了逼近的正、逆和等价定理,推广了左拟中插式Gamma算子在L_p空间中的逼近结果,改进了Gamma算子在Orlicz空间的逼近性质. 相似文献
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5.
再生核空间的有界线性算子的最佳逼近 总被引:1,自引:1,他引:0
讨论不同的再生核空间的有界线性算子的最佳逼近问题,利用空间的再生核给出了最佳逼近算子的表达式,并且对最佳逼近算子的收敛性进行了讨论. 相似文献
6.
刘生贵 《兰州理工大学学报》2013,39(3):151-154
对于二元非乘积型Lupas-Baskakov算子,结合逼近论和概率论的知识讨论该算子的极限,运用多元算子分解技巧得到该算子逼近的Voronovskaja型展式. 相似文献
7.
《辽宁工程技术大学学报(自然科学版)》2016,(12)
为得到广义Baskakov算子逼近的逆定理,利用泰勒展开式、算子矩量估计、Hold不等式等分析方法,推导了该算子逼近的强逆不等式.通过加权K-泛函,得到广义Baskakov算子逼近逆定理的特征刻画.研究结果表明,所得的结果整合和拓展了已有的成果. 相似文献
8.
丁春梅 《宁夏大学学报(自然科学版)》2002,23(3):222-223
研究Szasz型算子的局部点态和整体逼近定理,得到了逼近正逆定理,并用Ditzian-Totik模刻画了该算子局部点态和整体逼近的特征,所得结果统一了该算子点态和整体两种逼近特征的等价表征. 相似文献
9.
贾云锋 《兰州大学学报(自然科学版)》2006,42(1):95-97
讨论了二维Hilbert空间上线性算子正逼近的唯一性;对无限维Hilbert空间上存在唯一正逼近的线性算子进行了刻画;给出了一类线性算子不存在唯一正逼近的充分条件. 相似文献
10.
丁春梅 《宁夏大学学报(自然科学版)》2002,(3)
研究Sz sz型算子的局部点态和整体逼近定理,得到了逼近正逆定理,并用Ditzian Totik模刻画了该算子局部点态和整体逼近的特征,所得结果统一了该算子点态和整体两种逼近特征的等价表征. 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.
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.
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
14.
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
15.
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
16.
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
17.
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
18.
Michael Springborg 《华南师范大学学报(自然科学版)》2014,(6):136
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the 相似文献
19.
《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