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1.
3种群非线性捕食-被捕食反应扩散系统的奇摄动   总被引:1,自引:0,他引:1  
利用微分不等式方法研究一类生物数学中的非线性3种群捕食-被捕食模型的反应扩散系统奇摄动问题.在适当的条件下,利用微分不等式理论,讨论了一个初始边值问题解的存在性和渐近性态.微分不等式理论的实质是构造两个辅助函数作为系统的上、下解.然后使上、下解分别满足相应的不等式.最后证明所研究的系统存在解并处在上、下解之间.从而证明了系统解的存在性,并同时得到解的估计.  相似文献   

2.
具有脉冲效应的非自治捕食者-食饵系统周期正解   总被引:2,自引:0,他引:2  
讨论了一类具有脉冲效应的非自治捕食者-食饵系统的动力学行为.利用脉冲微分方程的比较定理.证明了系统的有界性,讨论了平凡周期解与半平凡周期解(食饵灭绝周期解)的局部稳定性.进而利用重合度理论证明了系统周期正解的存在性.  相似文献   

3.
在光学中研究多维(二维和三维)孤子引起了许多学者的关注,最重要的三维时空孤子时常被称作“光弹”.D.Mihalache等证明了非局域非线性介质中一个耦合系统存在稳定三维时空孤子.文章应用试探函数法,借助Maple软件,求得这个系统的时空光孤子解和周期解.结果表明,这个系统存在不同形式的包络孤子解和周期解.  相似文献   

4.
某类非自治二阶系统具鞍点特征的周期解的存在性   总被引:1,自引:0,他引:1  
研究一类非自治二阶系统周期解的存在性问题.利用鞍点约化方法,证明了该系统具鞍点特征的周期解的存在性,得到了一些新的可解性条件.  相似文献   

5.
研究时滞Belousov—Zhabotinskii系统行波解的存在性.首先利用变量代换将所研究的系统转化为常微分方程组,然后构造合适的上解和下解,得到系统行波解存在的充分条件.  相似文献   

6.
研究一类带有Size结构竞争种群系统平衡解的稳定性条件.利用不动点定理证明了平衡解的存在唯一性,并得出了平衡解的特征方程.  相似文献   

7.
应用预解矩阵R(n,m)讨论了一类非线性时滞系统解的有界性和零解的全局稳定性,同时给出了当系统为周期系统时周期解存在唯一的一组充分条件.  相似文献   

8.
研究了一类复杂概周期系统的概周期解的存在性,得到了保证其存在概周期解的充分条件.  相似文献   

9.
含时滞和扩散的n维互助型Lotka-Volterra系统波前解的存在性   总被引:1,自引:5,他引:1  
研究了含时滞和扩散的n维互助型Lotka-Volterra系统的行波解.利用J.Wu和X.Zou(J.Dynam,Diff.Eqns,2001,13(3):651~687.)建立的解的存在性理论,得到当时滞较小时,这个系统的波前解存在.  相似文献   

10.
研究受非线性微分包含(含伪单调算子)约束的最优控制存在世.借助于解的连续依赖性和逼近方法,证明了闭环系统解的存在性并获得其解集的紧性性质.解决了拉格朗日型最优控制的存在性。  相似文献   

11.
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.  相似文献   

12.
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。  相似文献   

13.
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.  相似文献   

14.
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-  相似文献   

15.
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-  相似文献   

16.
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  相似文献   

17.
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  相似文献   

18.
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  相似文献   

19.
<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  相似文献   

20.
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