  In this work, we collect quasi-simultaneous infrared, optical, X-ray and
$\gamma$-ray data of 60 $Fermi$-4LAC flat spectrum radio quasars (FSRQs). In
the framework of the conventional one-zone leptonic model, we investigate the
physical properties of $Fermi$-4LAC FSRQs' jets by modeling their
quasi-simultaneous spectral energy distributions (SEDs). Our main results are
summarized as follows. (1) There is a linear correlation between synchrotron
peak frequency and curvature of the electron energy distribution. As suggested
by previous works, the slope of the best linear fitting equation of this
correlation is consistent with statistic acceleration which needs a fluctuation
of fractional acceleration gain. (2) The gamma-ray dissipation regions are
located at the range from 0.1 to 10 pc away from the super-massive black hole,
and located outside the broad-line region (BLR) and within the dusty torus
(DT). (3) A size relation $P_{\rm e}$ (the kinetic power carried in
relativistic electrons) $\sim$ $P_{\rm B}$ (Poynting flux) $\leq$ $P_{\rm r}$
(the radiative power ) $<$ $P_{\rm p}$ (the kinetic power in cold protons) is
found in our modeling. Among them, $P_{\rm e}\sim P_{\rm B}$ suggests that SEDs
of almost all FSRQs with parameters are close to equipartition between the
magnetic field and the relativistic electrons. The $P_{\rm e} < P_{\rm r}$
suggest that the most energy of the relativistic electrons are dissipated by EC
radiation for FSRQs. (4) There is an anti-correlation between the peak energy
of SEDs ($\gamma_{\rm peak}$) and the jet power ($P_{\rm jet}$), which is
consistent with the blazar sequence.
