Cosmological Evolution of Quintessence and Phantom with a New Type of
  Interaction in Dark Sector
  In the present work, motivated by the work of Cai and Su [Phys. Rev. D {\bf
81}, 103514 (2010)], we propose a new type of interaction in dark sector, which
can change its sign when our universe changes from deceleration to
acceleration. We consider the cosmological evolution of quintessence and
phantom with this type of interaction, and find that there are some scaling
attractors which can help to alleviate the cosmological coincidence problem.
Our results also show that this new type of interaction can bring new features
to cosmology.
