Vocal communications in frogs and toads have been highly diversified and become a hot topic in the fields of herpetology,ecology,and behavioral neuroscience.The
The first aim of the paper is to study the Hermitizability of second-order differential operators,and then the corresponding isospectral operators.The explicit
Suppose that G is a finite group and H is a subgroup of G.H is said to be a p-CAP-subgroup of G if H either covers or avoids each pd-chief factor of G.We give s