  Thermal and transport properties of hot nuclear matter formed in central
$^{129}$Xe + $^{119}$Sn collisions at the Fermi energy are investigated using
the isospin-dependent quantum molecular dynamical (IQMD) model. Temperature
($T$), average density ($\rho$), chemical potential ($\mu$), mean momentum
($P$), shear viscosity ($\eta$) and entropy density ($s$) are obtained from the
phase-space information. The mean free path ($\lambda_{nn}$) and the in-medium
nucleon-nucleon cross section ($\sigma_{nn}$) in the highest compressible stage
at different incident energies are deduced and compared with the experimental
results from Phys. Rev. C $\bf{90}$ (2014) 064602. The result shows that
$\lambda_{nn}$ and $\sigma_{nn}$ have the same trend and similar values as the
experimental results when the beam energy is greater than 40 MeV/u at maximum
compressed state. Furthermore, the derived shear viscosity over entropy density
($\eta/s$) shows a decreasing behaviour to a saturated value around
$\frac{3}{4\pi}$ as a function of incident energy.
