Extension of the Bernstein condition to systems of ordinary differential equations of general form.
Extinction and permanence of a three-species Lotka-Volterra system with impulsive control strategies.
Extinction in a generalized Lotka-Volterra predator-prey model.
Extinction of a two species non-autonomous competitive system with Beddington-DeAngelis functional response and the effect of toxic substances
A two species non-autonomous competitive phytoplankton system with Beddington-DeAngelis functional response and the effect of toxic substances is proposed and studied in this paper. Sufficient conditions which guarantee the extinction of a species and global attractivity of the other one are obtained. The results obtained here generalize the main results of Li and Chen [Extinction in two dimensional nonautonomous Lotka-Volterra systems with the effect of toxic substances, Appl. Math. Comput. 182(2006)684-690]....
Extremal properties of distance-based graph invariants for -trees
Sharp bounds on some distance-based graph invariants of -vertex -trees are established in a unified approach, which may be viewed as the weighted Wiener index or weighted Harary index. The main techniques used in this paper are graph transformations and mathematical induction. Our results demonstrate that among -trees with vertices the extremal graphs with the maximal and the second maximal reciprocal sum-degree distance are coincident with graphs having the maximal and the second maximal reciprocal...