多步Runge-Kutta法求延时微分方程的P_m-稳定性

给出了多步Runge－Kutta法（MIRK）解延时微分方程（DDEs）的Pm-稳定性．着重研究此法用于下列具有m个延时量的线性试验方程时的稳定性态。u’（t）＝au（t）＋（t－τj），t≥0．u（t）＝（t），t≤0．其中a，bj（j＝1，2，…，m）　∈C，τm≥τ(m－1)≥…≥τ＞0，（t）给定．证明了m＝2时，MIRK法是P2－稳定的．对于m＞2，得到同样的结果（Pm－稳定）．     

具有多外延时量微分方程Runge-Kutta方法的GP_mL-稳定性

研究Runge－Kutta方法的GPmL-稳定性，着重研究用隐式Runge－Kutta方法去解如下方程时的数值稳定性，y’=（t）=Ly（t）＋M1y（t-τ1）＋…＋Mmy（t-τm），t≥0，y（t）=Φ（t），t＜0，其中L，Mi（i=1，…，m）是N×N复矩阵，0＜τ1≤τ2≤…≤τm，Φ（t）是一个已知向量函数，证明隐式RK方法是GPmL-稳定的当且仅当它是L-稳定的．     

多个滞时微分方程的Runge－Kutta法的数值稳定性分析

本文将Ｒｕｎｇｅ－Ｋｕｔｔａ法应用于解多个滞时的微分方程．主要研究该方法数值解线性试验方程ｙ＇（ｔ）＝ａｙ（ｔ）十ｂ１ｙ（ｔ—τ１）十ｂ２ｙ（ｔ—τ２）（其中τ２≥，τ１＞０，ａ，ｂ１，ｂ２为复数）的稳定性态．我们证明满足条件ｄｅｔ（Ｉ—ｘＡ）＝０ｄｅｔ［Ｉ—Ａ十ｘｅｂＴ」≠０（ｘ∈Ｃ）的Ｒｕｎｇｅ－Ｋｕｔｔａ法是ＧＰ－稳定的当且仅当该方法是Ａ－稳定的．     

延时微分方程多步Runge-Kutta方法的P-稳定性

用多步Runse－Kutta方法去解如下形式的试验方程其中y（t）＝（y1（t），y2（t），…，yN（t））T，L和M是复N×N矩阵，τ＞0，Φ（t）是一个已知向量函数，当t≥0时y（t）是未知的．主要解决了延时微分方程多步Runge－Kutta方法的P－稳定性．     

延时微分方程组的隐式Runge Kutta方法的P_mL稳定性

介绍了延时微分方程组的Ｐｍ Ｌ稳定性⒚用隐式ＲｕｎｇｅＫｕｔｔａ 方法去解如下形式的含有ｍ 个延时量的线性试验方程组：ｙ′（ｔ） ＝ ａｙ（ｔ） ＋ ｍｊ＝ １ｄｊｙ ｔ－ τｊ , ｔ≥０ｙ（ｔ） ＝ φ（ｔ） , 　　　　　　　　ｔ≤０其中ａ,ｂｊ（ｊ ＝ １,２,…,ｍ ） ∈Ｃ,τｍ ≥τｍ － １ ≥…≥τ１ ＞ ０⒀φ（ｔ） 是已知函数⒚当ｍ ＝ ２ 时,证明隐式ＲｕｎｇｅＫｕｔｔａ 方法是Ｐ２Ｌ稳定的充要条件是它为Ｌ稳定的⒚当ｍ ＞ ２ 时,此结论也成立⒚     

一类二阶中立型时滞微分方程的振动准则

本文主要利用H（ t,s）型函数和广义Riccati变换技巧,建立二阶中立型时滞拟线性微分方程[r（t）｜x′（t）｜γ－1x′（t）]′＋q0（t）｜y（t －σ）｜γ－1y（t －σ）＋q1（t）｜y（t －σ1）｜α－1y（t －σ1）＋q2（t）｜y（t －σ2）｜β－1y（t －σ2）＝0．其中x（t）＝y（t）＋p（t）y（t－τ）,在0≤p（t）≤1的新的振动准则．     

解抛物型方程的一种高精度加权差分格式

利用二阶徽商的四阶精度紧致差分逼近公式，给出解抛物型方程精度为O[1－20）t，t2＋x4]的一种新的加权差分格式，并通过Fourier方法讨论格式的稳定性．证明了当1／2≤θ≤1时，格式是无条件稳定的；当0≤θ＜1／2时，只有r≤1／3（1－2θ），格式才是稳定的，其中θ是加权参数（因子），t，x分别为时空方向的网格长度，r=（D是二阶导数项系数）．     

解中立型微分方程组的单参数方法的稳定性分析

研究单参数方法解中立型微分方程组ｘ＇（ｔ）＝Ａｘ（Ｌ－τ）＋Ｂｘ（ｌ）＋Ｃｘ＇（ｌ－τ）的数值稳定性性态，其中Ａ，Ｂ，Ｃ是实对称矩阵及τ＞０．并且，我们研究了稳定域的特征．     

随机系统的稳定性

研究了随机系统ｄｘ（ｔ）＝〖Ａ＋＾－Ａ（ｔ）ｘ（ｔ）＋（Ｂ＋＾－Ｂ（ｔ－τ１（ｔ））ｘ（ｔ－τ１（ｔ）〗ｄｔ＋ｇ（ｔ,ｘ（ｔ）,ｘ（ｔ－τ２（ｔ）ｄω（ｔ）的指数稳定性,引入对应的稳定性系统（无不确定性、随机扰动与时滞）ｘ（ｔ）＝（Ａ＋Ｂ）ｘ（ｔ）并设定是指数稳定的,应用Ｒａｚｕｍｉｋｈｉｎ定理证明了当不确定性＾－Ａ与＾－Ｂ、随机扰动ｇ及时滞τｉ（ｉ＝１,２）充分小时,原随机系统仍指数稳定。     

复合二项K－S算子和PoissonK－S算子逼迫

引入复合二项Ｋａｎｔｏｒｏｖｉｃｈ－Ｓｔｉｅｌｔｊｅｓ算子（Ｓ＿ｒｖ）（ｘ）＝Ｓ＿（ｋ，τ）（ｘ）（τ＞０，０≤ｘ≤１），证明了当τ→＋∞时，（Ｓ＿τｖ）（ｘ）在（０，１］上几乎处处收敛于ｖ关于Ｌｅｂｅｇｕｅ测度的绝对连续部份的Ｒａｄａｎ－Ｎｉｋｏｄｙｍ导数ｆ（ｘ）．同时也证明了ＰｏｉｓｓｏｎＫ－Ｓ算子（Ｓ＿τｖ）（ｘ）＝（τｄｖ）在［ａ，ｂ］（０，＋∞）上也有类似的结论．     

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.     

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     

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

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