  The acceleration of electrons in 3C 279 is investigated through analyzing the
injected electron energy distribution (EED) in a time-dependent synchrotron
self-Compton + external Compton emission model. In this model, it is assumed
that relativistic electrons are continuously injected into the emission region,
and the injected EED [$Q_e^\prime(\gamma^\prime)$] follows a single power-law
form with low- and high-energy cutoffs $\rm \gamma_{min}'$ and $\rm
\gamma_{max}'$, respectively, and the spectral index $n$, i.e,
$Q_e^\prime(\gamma^\prime)\propto\gamma^{\prime-n}$. This model is applied to
14 quasi-simultaneous spectral energy distributions (SEDs) of 3C 279. The
Markov Chain Monte Carlo fitting technique is performed to obtain the
best-fitting parameters and the uncertainties on the parameters. The results
show that the injected EED is well constrained in each state. The value of $n$
is in the range of 2.5 to 3.8, which is larger than that expected by the
classic non-relativistic shock acceleration. However, the large value of $n$
can be explained by the relativistic oblique shock acceleration. The flaring
activity seems to be related to an increased acceleration efficiency, reflected
in an increased $\gamma'_{\rm min}$ and electron injection power.
