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.Comment: Latex file, 20 page