  The finite-temperature transport properties of the spinless interacting
fermion model coupled to non-interacting leads are investigated. Employing the
unrestricted time-dependent Hartree-Fock (HF) approximation, the transmission
probability and the non-linear $I$-$V$ characteristics are calculated, and
compared with available analytical results and with numerical data obtained
from a Hubbard-Stratonovich decoupling of the interaction. In the weak
interaction regime, the HF approximation reproduces the gross features of the
exact $I$-$V$ characteristics but fails to account for subtle properties like
the particular power law for the reflected current in the interacting resonant
level model.
