I. RADIATIONLESS TRANSITIONS AND DEUTERIUM EFFECT ON LUMINESCENCE YIELDS AND LIFETIMES OF SOME AROMATIC HYDROCARBONS. II. TEMPERATURE DEPENDENCE OF INTERSYSTEM CROSSING IN SUBSTITUTED ANTHRACENES. III. CHARGE-TRANSFER INTERACTION BETWEEN SATURATED HYDROCARBONS AND IODINE. IV. DELAYED FLUORESCENCE OF DYES IN RIGID ORGANIC MATRICES.