“…Such results revealed the relationship between the asymptotic behavior of the solutions to nonlinear partial differential equations and the exponents of nonlinear internal sources. Different extension directions, such as different types of parabolic equations and systems in various of geometries with or without degeneracies or singularities, have been obtained since then, see the survey papers [8,18] and also the recent papers [2,19,22,29,30,34,35,36,38]. Among them, the Cauchy problem of the following coupled semilinear parabolic system was studied…”