一种改进的CGS方法

在分析ＣＧＳ算法的基础上,提出了采用两个相似的Ｂｉ－ＣＧ过程,利用Ｂｉ－ＣＧ过程的迭代中系数与迭代初值密切相关的特点,使其中一个Ｂｉ－ＣＧ的系数保证剩余向量与Ｋｒｙｌｏｖ子空间Ｋｋ（Ａ＾Ｔ,ｒ０）正交,百另一个Ｂｉ－ＣＧ过程的迭代系数使得剩余向量与Ｋｒｙｌｏｖ子空间Ｋ＾ｋｋ（Ａ＾Ｔ,Ｓ０）正交,构造出一种新的类似ＣＧＳ方法的求解大型系数矩阵稀疏线性方程组的迭代算法,数值实验表明这种算法在一定程度上     

基于自动区域故障模式与后果分析法的配电网可靠性评估

提出了一种基于配电块的简化网络可靠性FMEA算法.根据不同开关的功能,以自动开关装置为边界形成自动区域,将配电网络简化为只含开关、配电块及负荷的等效网络,每个自动区域仅含一个自动开关和若干个手动开关,由自动区域特性可知与该区域直接相连的所有支路的负荷点有相同的故障率,对于和自动区域直接相连的负荷而言,区域内元件故障对负荷点造成的故障停运时间相同.基于配电块的故障模式后果分析法,提出了形式化的简化配电网络可靠性评估算法.该算法只需一次枚举大大减少了重复枚举的数量,通过RBTS算例分析,证明了该方法的有效性.     

链路失效情况下网络点对联通可靠度的近似计算

基于连通性的网络可靠性分析是网络可靠性研究中的经典问题,根据具体问题的不同而采用的最小枚举、最小生成树枚举、边割集枚举、容斥原理、不交和方法等都是随机性网络可靠性指标的精确计算方法.这些计算方法在网络可靠性分析研究中具有重要的作用和意义,它们构成了网络可靠性分析计算的重要理论依据.然而对任意网络的k终端可靠度、全终端可靠度以及剩余边连通可靠度和点对联通可靠度,都已经证明他们的精确计算属于NP-hard问题[1][10].因此网络可靠性的估计是获得以上可靠性测度的重要手段.同时在网络的拓扑优化设计中,追求高可靠性的代价就是费用的无限增加,因此在一般商用的设计中,网络可靠性测度只要满足给定的标准即可,需要对不同的网络拓扑估计有关的可靠性值.     

计算3-Tree网络全终端可靠度的线性时间算法

对于一般网络,计算全终端可靠度是ＮＰ－难问题,３－Ｔｒｅｅ网络是一类具有特殊结构和性质的网络,利用三角子图到Ｋ４的化简,给出了一个计算３－Ｔｒｅｅ网络全终端可靠度的线性时间算法。     

一种有效的形式描述技术:GE-LOTOS

利用面向对象程序设计语言Ｊａｖａ完善从体ＬＯＴＯＳ到ＣＥ－ＬＯＴＯＳ的工具软件,使得以抽象层形式体现出来的ＧＥ－ＬＯＴＯＳ的某一子过程或所有子过程动态展开,而且为了方便用户,满足工业界和其它领域的要求,给出了一个从ＧＥ－ＬＯＴＯＳ到Ｅ－ＬＯＴＯＳ描述的一个算法。     

自适应的Runge－Kutta法

在分析ＲＫ法局部截断误差的基础上，对ＲＫ法实行适应控制，编制出结构紧凑，可靠性较强的通用算法。计算实践表明，本算法对计算复杂的微分方程甚至是Ｓｔｉｆｆ方程都是有效的。它具有计算简炼、精度高和数值稳定等特点。     

MgSiO3的分子动力学模拟

使用分子动力学模拟ＭｇＳｉＯ３以研究它的相变和超离子态．模拟采用Ｇｏｒｄｏｎ－Ｋｉｍ势和一种新的检测离子运动的技术．这项技术可以清楚地表现Ｏ２－离子的子晶格的熔解和八面体ＳｉＯ６的旋转．研究表明,ＭｇＳｉＯ３必须经历几番相变才能进入立方相．特别是在正交相和立方相之间存在一个过渡相．ＭｇＳｉＯ３确实存在超离子态相和立方相．这个超离子态相存在于熔点之前约２００～７００Ｋ．超离子态起始温度Ｔｃ和晶体熔点温度Ｔｍ的比率Ｔｃ／Ｔｍ～０．９２     

稀疏图上有效的MST多边更新并行算法

ＭＳＴ（最小生成树ＭｉｎｉｍｕｍＳｐａｎｎｉｎｇＴｒｅｅ之略）多边更新（ｕｐｄａｔｉｎｇ）问题定义如下：给定一个赋权图Ｇ（Ｖ,Ｅ）和Ｇ的一棵最小生成树Ｔ（Ｖ,ＥＴ）,其中｜Ｖ｜＝ｎ,ＥＴ是树边集合,（１）给Ｇ添加Ｋ条新边,或者（２）在图Ｇ上改变Ｋ条边的权后重新为Ｇ寻找一棵最小生成树,１≤Ｋ＜ｎ．本文基于ＳＩＭＤＣＲＥＷＰＲＡＭ共享存贮模型,运用“进－退”策略,并把这一特殊手段与已有的平行算法组合起来,为一类稀疏图（｜Ｅ-ＥＴ｜＝Ｏ（Ｋ））找到了一种有效的ＭＳＴ多边更新算法．该算法需要Ｏ（ｌｏｇｎｌｏｇＫ）时间和Ｏ（ｍａｘ｛ｎ,ｕＫ／ｌｏｇｎｌｏｇＫ｝）处理机．     

凸锥的一些重要性质及其在非线性规划中的应用

对与约束最优化相关的多面凸锥理论进行了讨论,证明了几个重要性质。利用正基,该文对线性约束的非线性规划问题设计了一种新算法。在该算法中,每次迭代时无需求解一个线性规划子问题,而且算法民比较简单。该文还证明了只要当目标函连续时,算法或有限步终止于一个Ｋ－Ｔ点,或产生一个无穷点列,其每一个聚点 Ｋ－Ｔ点。     

钠紫青铜NaMo6O17的热电势研究

报道了在１０～３００Ｋ温度范围内，对准二维电荷密度波导体ＮａＭｏ６Ｏ７紫青铜热电势的测量结果，在８０Ｋ附近ＮａＭｏ６Ｏ１７的热电势发生突变是该物质存在Ｐｅｉｅｒｌｓ相变的又一个实验例证，温度高于８０Ｋ时，热电势可以用一个经验公式，Ｓ＝ＡＴ＋Ｂ／Ｔ来描述，而在温度低于３０Ｋ时，热电势可以拟合为：Ｓ＝ＡＴ＋ＢＴ＾３，说明总的热电势均存在着自载流子自身的热扩散和声子对载流子的散射两方面的贡献，但高温区和     

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     

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

正~~     

Brief Introduction to “Journal of Jilin University( Science Edition) ”

<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 Peoples 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