Integrabilities of the $t-J$ Model with Impurities
  The hamiltonian with magnetic impurities coupled to the strongly correlated electron system is constructed from $t-J$ model. And it is diagonalized exactly by using the Bethe ansatz method. Our boundary matrices depend on the spins of the electrons. The Kondo problem in this system is discussed in details. The integral equations are derived with complex rapidities which describe the bound states in the system. The finite-size corrections for the ground-state energies are obtained. 
Zhan-Ning Hu, Fu-Cho Pu, (Institute of Physics, A.S., China) Yupeng   Wang (Cryogentic Laboratory, A.S., China)