On weak exponential expansiveness of evolution families in Banach spaces.

The aim of this paper is to give several characterizations for the property of weak exponential expansiveness for evolution families in Banach spaces. Variants for weak exponential expansiveness of some well-known results in stability theory (Datko (1973), Rolewicz (1986), Ichikawa (1984), and Megan et al. (2003)) are obtained.

4-Amino-1-(2-benzoyl-1-phenyl-eth-yl)-3-phenyl-1H-1,2,4-triazol-5(4H)-thione.

In the title compound, C(23)H(20)N(4)OS, the two phenyl rings of the diphenyl-propanone fragment form a dihedral angle of 86.8 (1)°, and the third phenyl ring attached to the triazole ring is twisted from the latter at 40.1 (1)°. In the crystal, mol-ecules are paired into centrosymmetric dimers via pairs of inter-molecular N-H⋯O and N-H⋯S hydrogen bonds.