“…Note that decreasing perturbations with power-law asymptotics appear, for example, in the study of Painlevé equations [26,27], phase-locking phenomena [28][29][30], stochastic perturbations [31,32], and in a wide range of other problems associated with nonlinear non-autonomous systems [33,34]. The evolution of I(t) = H(x(t), ẋ(t)) for solutions of ( 5) with different values of the parameters B, s and initial data.…”