  We investigate the density fluctuations induced by hadronic interactions at
low temperatures and large chemical potentials after the hadronization of
quark-gluon plasma~(QGP). We analyze the structures of net-baryon number
kurtosis and skewness and elaborate on their relations with the nuclear
liquid-gas~(LG) phase transition and hadronic interactions above the critical
temperature. Combining with the relevant experimental projects at
RHIC/NICA/FAIR/J-PARC/HIAF with collision energies from $200\,$GeV to
$1.8\,$GeV, we propose a double-peak structure of kurtosis (skewness) as a
function of collision energy, which can be taken to identify the chiral phase
transition and the nuclear liquid-gas phase transition. In particular, the
fluctuation distributions at low temperatures provide a new method to explore
hadronic interactions and nuclear liquid-gas transition.
