Duality of Super D-brane Actions in General Type IIB Supergravity Background

We examine duality transformations of supersymmetric and $\kappa$-symmetric Dp-brane actions in a general type II supergravity background where in particular the dilaton and the axion are supposed to not be zero or a constant but a general superfield. Due to non-constant dilaton and axion, we can explicitly show that the dilaton and the axion as well as the two 2-form gauge potentials transform as doublets under the $SL(2,R)$ transformation from the point of view of the world-volume field theory.