  The fast radio bursts ( FRBs ) are energetic radio bursts with millisecond
duration only observed at radio frequencies. The generation mechanism is still
mysterious. We have proposed a generation mechanism of both repeating and
one-off FRBs. They arise from the axion star collision with neutron star or
magnetized accretion disk of galactic black hole. Once we accept the existence
of the axions, we find that the mechanism well explain previously observed
spectral-temporal features. In this paper we show that it also explains
recently observed phenomena such as downward drifting in the repeating FRBs,
etc.. Analysis of the downward drifting based on Doppler effects has been
presented in recent papers, in which a superradiance system of molecular or
atom has been proposed as a source of FRBs. We apply the analysis to our
mechanism and find that it well explains the relation between the downward
drifting rate and the duration of the repeating FRBs. The Doppler effects lead
to the fact that the duration of radio burst with higher center frequency is
shorter than that of radio burst with lower center frequency in the repeating
FRBs. Our generation mechanism naturally explain polarization angle swing
observed in the repeating FRB180301 and one-off FRBs. We also discuss the
association between the FRB200428 and magnetar SGR J1935+2154. The X ray burst
observed just after the observation of the FRB could be triggered by the axion
star collision with the magnetar. We also explain the consistency of our
generation mechanism with observed spectral-temporal differences in the
repeating and one-off FRBs, e.g. longer duration ( smaller flux density ) of
repeating FRBs than duration ( flux density ) of one-off FRBs.
