Integrable boundary impurities in the t-J model with different gradings
  We investigate the generalized supersymmetric $t-J$ model with boundary impurities in different gradings. All three different gradings: fermion, fermion, boson (FFB), boson, fermion, fermion (BFF) and fermion, boson, fermion (FBF), are studied for the generalized supersymmetric $t-J$ model. Boundary K-matrix operators are found for the different gradings. By using the graded algebraic Bethe ansatz method, we obtain the eigenvalues and the corresponding Bethe ansatz equations for the transfer matrix. 
Heng Fan, Miki Wadati