解四阶抛物型方程高精度恒稳的隐式格式

对四阶抛物型方程ut+uxxxx=0构造了一类三层隐式差分格式,它们含有非负参数α1,α2和α3,其局部截断误差至少是O(Δt2+Δt6).在条件α1≥α3≥0,0≤α2≤及α1+α2+α3=1之下,该格式绝对稳定且可用追赶法求解.     

四阶抛物型方程两类新的恒稳差分格式

对四阶抛物型方程Ｕｔ＋Ｕｘｘｘｘ＝０提出两类新的三层隐式差分格式，其局部截断误差阶分别为Ｏ（Δｔ２＋Δｘ２）和Ｏ（Δｔ２＋Δｘ４）．当参数适当选取时，这些格式都是绝对稳定的且可用追赶法求解．数值例子表明这些格式是有效的．     

抛物型方程的一族双参数高精度恒稳格式

对抛物型方程，构造一族含双参数的三层高精度隐式差分格式。在特殊情况下，当参数α1／2和β＝0时，得到一个两层格式。同时，证明该放格式对任意非负参数都是绝对稳定的，并且其截断误差阶为O（（Δt)^2 (Δx)^6).数值例子表明，该族格式是有效的，且理论分析与实际计算相吻合。     

Schrödinger方程一族高精度恒稳差分格式

Schrodinger方程((e)u)/((e)t)=I((e)2u)/((e)x2),可构造一族含双参数的三层高精度隐式差分格式.当参数α=1/2, β=0时得到一个双层格式.证明该格式对任意非负参数α≥0, β≥0都是绝对稳定的,并且其截断误差阶为O(Δt2+Δx4).数值例子表明,文中所建立的差分格式是有效的,理论分析与实际计算相吻合.     

Schr(o)dinger方程一族高精度恒稳差分格式

Schrodinger方程((e)u)/((e)t)=I((e)2u)/((e)x2),可构造一族含双参数的三层高精度隐式差分格式.当参数α=1/2, β=0时得到一个双层格式.证明该格式对任意非负参数α≥0, β≥0都是绝对稳定的,并且其截断误差阶为O(Δt2+Δx4).数值例子表明,文中所建立的差分格式是有效的,理论分析与实际计算相吻合.     

Schrdinger方程一族高精度恒稳差分格式

Schrodinger方程 u t=i 2 u x2,可构造一族含双参数的三层高精度隐式差分格式 当参数α =1/ 2,β =0时得到一个双层格式 证明该格式对任意非负参数α≥ 0,β≥ 0都是绝对稳定的,并且其截断误差阶为O(Δt2 +Δx4) 数值例子表明,文中所建立的差分格式是有效的,理论分析与实际计算相吻合     

一类演化方程的一族高精度恒稳差分格式

对一类演化方程 u t=a 2m + 1 x1m + 1(a为常数 ,m =1 ,2 ,… ) ,构造一族含双参数的三层高精度隐式差分格式 .当参数α =12 ,β =0时 ,得到一个双层格式 证明对一切正整数m ,该格式对任意非负参数α≥ 0 ,β≥ 0都是绝对稳定的 ,并且其截断误差阶为O((Δt) 2 +(Δx) 6) .数值例子表明 ,所建立的差分格式是有效的 ,理论分析与实际计算相吻合     

求解一维对流扩散反应方程的一种隐式差分格式

提出了数值求解一维非稳态对流扩散反应方程的一种隐式差分格式。首先将模型方程利用指数函数转化为对流扩散方程,构造它的差分格式,然后对差分方程的系数进行相应处理,并进行回代,得到对流扩散反应方程的隐式差分格式,其截断误差为O(τ2+h2),采用von Neumann方法证明了格式是无条件稳定的,并且由于每一时间层上只用到了3个网格点,所以可直接采用追赶法求解差分方程,数值结果显示了算法的有效性。     

抛物型方程的一族高精度恒稳格式

对二阶抛物型方程ｕｔ＝ｕｘｘ,构造了一族新的三层隐式差分格式（在特殊情况下是两层）,它们含有非负参数ａ１,ａ２和ａ３,其截断误差至少可达Ｏ（△ｔ）＾２＋（△ｘ）＾４）,对三层格式,在条件ａ１≥ａ２≥０,ａ２≤１／２及ａ１＋ａ２＋ａ３＝１之下绝对稳定,特别地,在条件ａ１＝０,ａ２＝ａ３或ａ１＝ａ２,ａ３＝０之下成为两层不含参数的隐式格式,且也是绝对稳定的。这些格式均可用追赶法求解,在该格式中,选取适     

二维抛物型方程的高精度分支稳定隐格式

用待定系数法构造了求解二维抛物型方程的高精度分支稳定隐式差分格式.格式的截断误差达到O(Δt2+Δx4).证明了当r≥1/6时,差分格式是稳定的.通过数值试验,比较了差分格式的解和精确解的区别,说明了差分格式的有效性.     

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     

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