@article{(Open Science Index):https://publications.waset.org/pdf/15619, title = {Positive Periodic Solutions in a Discrete Competitive System with the Effect of Toxic Substances}, author = {Changjin Xu and Qianhong Zhang}, country = {}, institution = {}, abstract = {In this paper, a delayed competitive system with the effect of toxic substances is investigated. With the aid of differential equations with piecewise constant arguments, a discrete analogue of continuous non-autonomous delayed competitive system with the effect of toxic substances is proposed. By using Gaines and Mawhin,s continuation theorem of coincidence degree theory, a easily verifiable sufficient condition for the existence of positive solutions of difference equations is obtained. }, journal = {International Journal of Mathematical and Computational Sciences}, volume = {5}, number = {4}, year = {2011}, pages = {649 - 653}, ee = {https://publications.waset.org/pdf/15619}, url = {https://publications.waset.org/vol/52}, bibsource = {https://publications.waset.org/}, issn = {eISSN: 1307-6892}, publisher = {World Academy of Science, Engineering and Technology}, index = {Open Science Index 52, 2011}, }