两种群相互竞争具有脉冲预防接种的SIR传染病模型

研究了一类具有脉冲预防接种的两种群相互竞争S(易感染者)-I(感染者)-R(治愈者)传染病模型,讨论了平衡点的存在性和局部渐进稳定性,脉冲接种有效的预防种群内,及其竞争种群间传染病的传播和蔓延。该接种方法可以在珍稀物种中推广。     

一类具有时滞和脉冲接种的SEIRS传染病模型

研究了一类具有时滞和脉冲接种的SEIRS传染病模型,应用脉冲微分方程比较定理和分析的方法得到了无病周期解的全局吸引性和系统持久性的充分条件,结果表明了时滞、非线性发生率、脉冲接种以及免疫力丧失对模型动力学性质的影响.     

一类对染病者实施连续接种和脉冲接种的时滞 SIR 传染病模型的比较

考虑了时滞方程的两类接种策略.连续接种的系统中,研究了无病平衡点的局部渐近稳定性和地方病平衡点的全局渐近稳定性;脉冲作用下的传染病模型,利用脉冲比较定理和微分不等式得到了无病周期解的全局吸引性的条件,最后对两类接种进行了比较并得出结论.     

具有脉冲出生和脉冲接种的SEIR模型

建立并分析了一个具有脉冲出生和脉冲接种的传染病模型,根据脉冲微分方程理论得到了无病周期解局部渐近稳定的和全局稳定充分条件.     

具有脉冲接种和阶段传染的SIVR流行病模型分析

本文讨论了一类具有脉冲接种和阶段传染的SIVR传染病模型,利用不动点定理证明了该模型无病周期解的存在性,利用Floquet乘子理论和脉冲微分方程比较定理得到了无病周期解全局渐近稳定的充分条件.     

一类具有脉冲接种的SIQRS传染病模型的稳定性分析

研究具有常数输入及非线性传染率的脉冲接种SIQRS传染病模型,利用脉冲微分方程的Floquet定理及比较定理得到了无病周期解全局渐近稳定的充分条件及系统一致持久的充分条件.     

具有两个时滞的SEIRS脉冲接种模型的周期解

讨论了具有两个时滞的传染病脉冲接种模型,考虑了周期解的存在性和全局吸引性.     

SIRS传染病模型的连续接种和脉冲接种的比较

考虑了脉冲作用下的传染病模型,利用频闪映射及Floquet定理证明了具有脉冲接种且传染率为饱和的SIRS传染病模型的无病周期解的存在性,并多次利用比较原理和脉冲微分不等式证明了无病周期解的全局渐近稳定性.最后,对连续接种和脉冲接种作了比较,得出了相关的结论.     

一类带脉冲接种和脉冲剔除的SIR传染病模型的稳定性态

文章研究了一类具有脉冲接种和脉冲剔除的SIR传染病模型的动力学性态．应用Floquet定理研究了无病周期解的局部稳定性，通过脉冲微分不等式证明了其全局渐近稳定性．     

具有饱和接触率的SIQR传染病模型的不同控制策略

讨论了带有隔离和不同接种策略的SIQR传染病模型.在连续接种策略下给出了无病平衡点和地方病平衡点的存在性和全局稳定性;在脉冲接种策略下,获得了无病周期解,并给出了无病周期解全局稳定的充分条件,同时也讨论了隔离率、连续接种率、脉冲接种率、治疗率等参数对疾病防治的重要性.     

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     

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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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