非精确线搜索条件下共轭梯度法的收敛性分析

对Hideaki与Yasushi提出的两种使用目标函数值的共轭梯度法进行了研究,在一种新的Wolfe型线搜索条件下分析了它们的收敛性质.通过讨论可知,在其它的非精确线搜索条件下这两种共轭梯度法也是可行的.最后的数值试验表明了所给共轭梯度法的有效性.     

一种新线性搜索下的混合共轭梯度法

共轭梯度法是求解大规模无约束问题的一种有效方法，文章针对算法的优劣主要依赖于步长因子和搜索方向的特点，结合共轭梯度法的共轭性质，在HS方法和DY方法的基础上，提出了一种混合共轭梯度法，并证明了全局收敛性。     

结合Armijo步长搜索的一类新记忆梯度算法及其收敛特征

对于求解无约束规划的共轭梯度算法中的共轭梯度方向参数，给定一个假设条件，确定它的一个取值范围，以保证搜索方向是目标函数的充分下降方向，由此提出了一类新的记忆梯度算法。在去掉迭代点列有界和Armijo步长搜索下，讨论了算法的全局收敛性，同时给出了结合FR、PR、HS共轭梯度算法的修正形式。数值实验表明，新算法比Armijo步长搜索下的FR、PR、HS共轭梯度法更稳定、更有效。     

线性约束优化问题的共轭梯度型算法及其收敛性

将共轭梯度法与广义投影技术相结合，给出了一个求解带线性等式、不等式约束优化问题的共轭梯度型算法，证明了算法的性质及全局敛性，首次将共轭梯度法推广应用于求解带约束条件的优化问题。     

LS—共轭梯度算法的收敛性

对无约束规划（P）：minx∈R^nf(x)。其中f(x)是Rn→R^1上的二阶连续可微函数，通过引入强迫函数和逆连续模函数，证明了一类采用Curry-Altman步长规则的LS-共轭梯度算法的全局收敛性质，利用比较原理进一步讨论了LS-共轭梯度算法在采用另外三种步长规则下的全局收敛性。     

修正的HS共轭梯度算法的全局收敛性

对求解无约束优化问题的共轭梯度法中的方向参数给定新的区间取法，将HS共轭梯度参数限制在此区间上，保证搜索方向是目标函数的充分下降方向，在此基础上提出了修正HS共轭梯度算法（MHS），并在较弱的条件下讨论了新算法在广义Armijo步长搜索下的全局收敛性。数值试验结果表明，新算法比广义Armijo步长搜索下的FR、PR、HS共轭梯度算法有效。     

一种求解无约束优化问题的共轭梯度法

共轭梯度法是求解大规模无约束问题的一种有效方法,本文针对算法的优劣主要依赖于步长因子和搜索方向的特点,结合共轭梯度法的共轭性质,在HS方法和DY方法的基础上,提出了一种混合共轭梯度法,并证明了全局收敛性.     

几类非精确线搜索下共轭梯度法的收敛条件

在几类非精确线搜索下讨论一般共轭梯度法的收敛条件，运用此条件，对一类新算法的收敛性进行分析。     

无约束最优化的共轭梯度路非单调信赖域算法

提供了无约束最优化问题的共轭梯度路径非单调信赖域算法。进而获得了共轭梯度路的一些重要性质。基于这些性质和一些合理的假设，证明了算法具有整体收敛性和保持局部超线性收敛速率。     

一类具有充分下降性的DL共轭梯度法

针对无约束优化问题,利用两项共轭梯度法(DL方法)去逼近改进的HS三项共轭梯度法,提出了改进的DL共轭梯度法即MDL共轭梯度法.该方法相对于DL方法具有一个更好的性质,即该共轭梯度法的搜索方向不依赖任何线搜索就可满足充分下降条件,理论上证明了该方法在Wolfe线搜索条件下对一般函数具有全局收敛性.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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