657245.fig.004a
(a)
657245.fig.004b
(b)
657245.fig.004c
(c)
657245.fig.004d
(d)
Figure 4: Different dynamical behaviors of system (13) with fixed parameter values , and two groups of initial conditions and for , respectively; (a) period-one orbits when ; (b) period-two orbits when ; (c) period-four orbits when ; (d) separate single-scroll chaotic attractors when .