Fig. 8.

The dynamics of system (20) when $({\mathit{\alpha }}_1,{\mathit{\alpha }}_2)$ across the lines $H_d$ from the bottom up. a System (20) has two locally asymptotically stable nontrivial equilibria and a stable limit cycle when $({\mathit{\alpha }}_1,{\mathit{\alpha }}_2)=(0.006,-0.00112)$ with initial conditions $(-0.00005,0.0,0.0,0.0,0.0,0.0)$ (the red curve), $(0.00005,0.0,0.0,0.0,0.0,0.0)$ (the blue curve) and $(-0.02,0.0,0.0,0.0,0.0,0.0)$ (the black curve), respectively. b The case of $({\mathit{\alpha }}_1,{\mathit{\alpha }}_2)=(0.006,0)$ where initial conditions are same as a. (Color figure online)