任睿超,劉小剛
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具變時滯Holling功能反應的維Lotka-Volterra系統(tǒng)的正周期解
任睿超[1],劉小剛
(西北大學現(xiàn)代學院 基礎部,陜西 西安710130)
利用Mawhin重合度定理討論了一類帶Holling功能反應項的變時滯維Lotka-Volterra競爭模型正周期解的存在性,給出了與變時滯無關(guān)的充分條件,改進了現(xiàn)有的結(jié)論.
Holling功能反應;正周期解;Mawhin重合度定理
1引言及預備知識
競爭種群動力學模型中,Lotka-Volterra系統(tǒng)已被眾學者廣泛研究,但大都停留在常時滯或低維單變時滯階段,而高維多變時滯系統(tǒng)僅被少數(shù)學者研究,尤其是帶有Holling功能反應的競爭模型,很多結(jié)論尚未完善.在最新研究中,文獻[1-7]用Mawhin重合度定理討論了不同情況下維非自治生物種群模型的正周期解的存在性,得到了一些新的結(jié)論.
引理1[1]93若是的反函數(shù),則也是嚴格正的周期連續(xù)函數(shù).
引理2(Mawhin重合度定理)[8]設,是Banach空間,是指標為0的Fredholm映射,在上為緊的,是中的任意有界開集,且滿足
2主要結(jié)果及證明
定理若系統(tǒng)(1)滿足:
同理
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[2] Xia Y H.New conditions on the existence and stability of periodic solutions in Lotka-Volterra′s polulation system[J].SIAM J Appl Math,2009,69:1580-1597
[4] Lü X.Existence ang global attractivity of positive periodic solutions of Lotka-Volterra predator-prey systems with deviating arguments[J].Nonliear Anal Real World Appl,2010,11:574-583
[5] Tang X H.Global attractivity of positive periodic solutions to periodic Lotka-Volterra competition systems with pure delay[J].J Differ Equ,2006(228):580-610
[6] Tang X H.On positive periodic solutions of Lotka-Volterra competition systems with deviating arguments[J].Proc Am Math Soc, 2006(134):2967-2974
[7] 劉振杰.具有時滯Beddington-DeAnglelis功能性反應的種群食物鏈系統(tǒng)的周期解[J].黑龍江大學自然科學學報,2008,25(2):277-280
[8] Gaines R E,Mawhin J L.Coincidence Degree and Nonlinear Differential Equations[M].Berlin:Springer-Verlay,1977
Positive periodic solution ofdimensional Lotka-Volterra system with multiple varying delays and Holling function response
REN Rui-chao,LIU Xiao-gang
(Department of Basic Course,Modern College of Northwest University,Xi′an 710130,China)
The existence of positive periodic solutions of a class variable delay Lotka-Volterra competition model with Holling functional response was discussed by using Mawhin's coincidence degree theorem,and time varying delay independent sufficient conditions was given,the existing conclusions was improved.
Holling functional response;positive periodic solution;Mawhin coincidence degree theorem
O175.12
A
10.3969/j.issn.1007-9831.2016.04.001
2015-12-28
2014年陜西省教育廳專項科研計劃項目(14JK2146)
任睿超(1985-),男,陜西西安人,講師,碩士,從事微分方程與動力系統(tǒng)研究.E-mail:rrc8512@163.com
1007-9831(2016)04-0001-04