  The $ND$ and $NB$ systems with $I=0$ and $1$, $J^{P}=\frac{1}{2}^{\pm}$,
$\frac{3}{2}^{\pm}$, and $\frac{5}{2}^{\pm}$ are investigated within the
framework of quark delocalization color screening model. The results show that
all the positive parity states are unbound. By coupling to the $ND^{*}$
channel, the state $ND$ with $I=0,~J^{P}=\frac{1}{2}^{-}$ can form a bound
state, which can be invoked to explain the observed $\Sigma(2800)$ state. The
mass of the $ND^{*}$ with $I=0,~J^{P}=\frac{3}{2}^{-}$ is close to that of the
reported $\Lambda_{c}(2940)^{+}$, which indicates that $\Lambda_{c}(2940)^{+}$
can be explained as a $ND^{*}$ molecular state in QDCSM. Besides, the $\Delta
D^{*}$ with $I=1,~J^{P}=\frac{5}{2}^{-}$ is also a possible resonance state.
The results of the bottom case of $NB$ system are similar to those of the $ND$
system. Searching for these states will be a challenging subject of
experiments.
