Acta mathematica scientia,Series A ›› 2020, Vol. 40 ›› Issue (5): 1175-1185.

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Existence and Uniqueness of Positive Solutions to an Unstirred Chemostat with Toxins

Haixia Li()   

  1. Institute of Mathematics and Information Science, Baoji University of Arts and Sciences, Shaanxi Baoji 721013
  • Received:2019-09-18 Online:2020-10-26 Published:2020-11-04
  • Supported by:
    the NSFC(11801013);the Natural Science Basic Research Plan in Shaanxi Province of China(2014JQ2-1003);the Science and Technology Project in Baoji City(2018JH-20);the Doctoral Research Project of Baoji University of Arts and Sciences(ZK2018069)

Abstract:

A food chain model in the unstirred chemostat with toxins is studied. The stability of the trivial solution and semi-trivial solution is analyzed by means of the stability theory, and a priori estimate of positive solution is given by the maximum principle and the super and sub-solution method. Then, by using the fixed point index theory, the sufficient conditions for the existence of positive solutions are achieved. Finally, the effect of the toxins on the dynamic behavior is discussed by virtue of the perturbation theory and bifurcation theory, and the stability and uniqueness of positive solutions are obtained. The results show that the species can coexist when the growth rates of the microorganisms u and v are larger in the presence of the toxins. Furthermore, if the effect of the toxins is sufficiently large, the system has unique stable positive solution when the growth rate of the microorganism v belongs to a certain range.

Key words: Chemostat model, Toxins, Fixed point index theory, Bifurcation theory, Perturbation theory, Uniqueness

CLC Number: 

  • O175.26
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