Benjamin-Bona-Mahoney方程的行波解

目的 建立5个方程新的行波解.方法 借助于双曲正切方法, 有理正余弦方法和正余弦方法.结果与结论 构造了方程有理三角正余弦形式解, 获得了方程周期解, 复数解, 钟形孤立子解.     

一种利用不可行解的贝叶斯网学习算法

现有的基于打分搜索的贝叶斯网学习方法都是利用满足有向无环图的可行解进行学习.在搜索过程中遇到不可行解时,这类算法简单地去除不可行解或将不可行解转化为可行解.然而,有的不可行解中往往蕴含着有价值的信息.本文提出一种新的贝叶斯网学习方法ISEC,同时利用可行解和不可行解学习贝叶斯网络,并提出针对不可行解的选择策略,在学习过程中可以有效地利用不可行解中的有用信息.实验结果表明,ISEC能够比仅利用可行解的方法更快地学习到更优的贝叶斯网.     

偏微分方程解的一种新求法

求非线性偏微分方程的精确解是非常重要的.为了获得它的精确解研究人员做了大量的工作.本文获得了Burgers方程和Boussinesq方程组的全新的精确解.具体的方法如下:首先对方程进行行波变换得到新方程,之后给定它的拟解,将拟解代入新方程,而得到一个方程组,借助计算机代数系统Mathematica解此方程组,以确定拟解,即为全新的精确解.这种方法求得Burgers方程和Boussinesq方程组的精确解,包含了某些文献的结果,也修正了某些文献的结论.这种方法可以求一系列的偏微分方程的精确解.     

基于He-变分方法求弱色散解非线性波动方程的孤子解

利用He-变分方法,构造并解得了弱色散解非线性波动方程的孤子解.此外,该方法也可以适用于求解其它非线性偏微分方程的精确解.     

用最优化方法计算时滞微分方程的周期解

给出一种用最优化方法计算时滞微分方程周期解的方法. 该方法先将寻找时滞微分方程周期解的问题转化为一个有约束的最优化问题, 再用最优化方法计算周期解. 在数值计算上, 应用函数拟合的方法近似逼近初始函数, 并结合牛顿法和惩罚函数法数值求得周期解. 数值实验结果验证了方法的高效性.     

数值延拓法求常微分方程边值问题数值解的可行性

解非线性常微分方程边值问题数值解通常可归结为解非线性差分方程组.解非线性方程组的数值延拓法是扩大给定方法收敛域的一种尝试.本文正是利用这种方法研究了非线性二阶常微分方程边值问题数值解的计算问题,并给出检验其算法为可行的充分条件.     

长短波共振方程的显式精确解

通过扩展的双曲函数方法获得了描述长短波相互作用的非线性发展方程的显式精确解.这些解包括S和L的钟状孤立波解,S的扭状及L的钟状孤立波解,S和L的钟状与扭状复合的孤立波解,4种奇异行波解,6种三角函数状周期波解,有理函数型行波解.展示了长短波方程精确解的结构的多样性.该方法也可以用于求多维非线性波方程的精确解.     

SK-KP方程的精确解

应用广义(G'/G)展开方法 求解非线性发展方程的精确解.本文利用此方法 求解SK-KP方程,得到了方程的双曲函数解、三角函数解和有理函数解等.     

基于信赖域方法的矿井通风网络解算

针对在通风网络解算中,若初始值选择不当,Hession矩阵不正定,将导致迭代次数显著增加.为了解决此问题,采用基于信赖域方法的求解大型非线性方程组进行网络解算.应用信赖域方法求得非线性方程组的解,即为网络解算的结果.对基于信赖域方法的矿井通风网络解算进行研究探讨,具有一定的理论指导意义.     

Boussinesq方程新的显式行波解

利用一种基于符号计算的代数方法,结合M ap le环境中的Epsilon软件包,求解Boussinesq方程,获得了若干其它方法不曾给出的形式更为丰富的新的显式行波解,其中包括孤波解、三角函数解、有理函数解、Jacob i椭圆函数周期解和W e ierstrass椭圆函数周期解.与文献[8,15]相比,本文的方法更为简便、易行.将该方法应用于其它非线性波方程(组)中,可获得更多的显式行波解.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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