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1.
函数凸性及其广义凸性是函数的重要性质之一,对凸函数进行分类和推广是研究函数凸性及其广义凸性的一个重要途径.在研究凸函数、Godunova-Levin函数、P-函数和s-凸函数的基础上,针对几何凸函数的推广问题,提出了几何s-凸函数的概念,通过分析几何s-凸函数的凸性特征,给出了几何s-凸函数的若干判定定理和运算性质,建立了几何s-凸函数的Jensen型不等式和Hadamard型不等式.几何s-凸函数概念的建立为研究新的凸函数和拓展凸函数概念开辟了一条新途径.  相似文献   

2.
基于对凸性及其广义凸性的进一步考虑,提出了MG-凸函数的概念,研究了MG-凸函数的凸性特征,给出了MG-凸函数判定方法、运算性质,建立了关于MG-凸函数的离散型Jensen不等式,并指出几何凸函数、对数凸函数(AG-凸函数)、HG-凸函数都是其特殊形式。  相似文献   

3.
考虑了函数的凸性及其广义凸性,提出并研究了r次幂平均s-凸函数,讨论了它的若干判定定理及运算性质,建立了其Jensen型不等式,并给出了Jensen型不等式的等价形式及推论.研究结果表明,r次幂平均s-凸函数是算术凸函数(凸函数)、几何凸函数、调和凸函数、平方凸函数、调和平方凸函数以及r-平均凸函数的推广,为研究新的凸函数和推广拓展凸函数概念探索了一条新途径.  相似文献   

4.
给出一类新的广义凸函数--严格F-G广义凸函数,并给出条件P1、P2及其性质,研究严格F-G广义凸函数的若干性质,给出严格F-G广义凸函数的两个充分条件,指出在一定条件下,满足中间点严格F-G广义凸性的F-G广义凸函数是严格F-G广义凸函数,满足中间点严格F-G广义凸性的半严格F-G广义凸函数是严格F-G广义凸函数.最...  相似文献   

5.
针对凸度量空间中的抽象凸结构,提出了3种新广义W-凸函数,以及利用中点W-凸性研究了凸度量空间中广义凸性的方法。首先,将线性空间中基于标准凸结构的3种广义凸函数概念引入了凸度量空间,定义了3种新广义W-凸函数;其次,在适当条件下,证明了中间点W-凸函数是中点W-凸函数,也是[0,1]∩Q-W-凸函数,进而获得了稠密性定理,并讨论了稠密性定理在极小化问题和多目标规划问题中的应用;最后,在中点W-凸性以及上半连续性或下半连续性或W-拟凸性或W-严格拟凸性或W-半严格拟凸性等条件下,建立了W-凸函数的一些判别准则。获得的稠密性定理与利用中点凸性建立判别准则的方法,可以应用于其他类型凸性或广义凸性相关问题的研究。  相似文献   

6.
文章基于应用中对函数凸性的特殊要求的考虑,针对凸函数、对数凸函数、AH-凸函数的推广问题,提出AM-凸函数的定义,讨论AM-凸函数的判别方法并给出相应的判定定理,分析了AM-凸函数的凸性特征,得到其若干凸性性质,进而建立了AM-凸函数的Jensen型不等式。  相似文献   

7.
给出一类新的广义凸函数--严格F-G广义凸函数,并给出条件P1、P2及其性质,研究严格F-G广义凸函数的若干性质,给出严格F-G广义凸函数的两个充分条件,指出在一定条件下,满足中间点严格F-G广义凸性的F-G广义凸函数是严格F-G广义凸函数,满足中间点严格F-G广义凸性的半严格F-G广义凸函数是严格F-G广义凸函数.最后给出严格F-G广义凸函数在极小化问题中的一个实际应用.  相似文献   

8.
基于对函数凸性的进一步考虑,给出了调和平方凸函数的概念、判定定理及其运算性质,建立了调和平方凸函数的Jensen型不等式.  相似文献   

9.
针对一个完全对称函数的复合函数Schur凸性问题,基于Schur凸函数的性质给出了已有结果的又一证明.证明的主要思想方法是构造合适的复合函数,并利用复合函数的Schur凸性、Schur凸函数与Schur乘性凸函数或Schur调和凸函数的关系,给出了完全对称函数的复合函数Schur凸性、Schur乘性凸性和Schur调和性的简单证明.  相似文献   

10.
【目的】对于广义凸集与广义凸函数的研究是十分基础而重要的课题,只有广义凸性的基础理论研究不断完善,对广义凸规划的全面深入的研究才会成为可能。【方法】受凸函数的一个基本结果启发,给出概念并借助相关结果开展论证。【结果】简化了已有文献所给出的广义凸函数概念,指出函数的广义凸性与函数上图的广义凸性之间的等价关系,并给出下半连续前提下,F-G广义凸函数与F-G广义弱凸函数之间等价性的新证明。最后,指出函数的广义凸性与函数水平集的广义凸性之间的内在联系。【结论】将广义凸集和广义凸函数统一在一个结构框架下进行研究,建立了二者之间的桥梁纽带。
  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.
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.  相似文献   

18.
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   

19.
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   

20.
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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