Exact results for a one-dmensional t-J model with impurity
  We propose a simple idea to construct 1D integrable models with impurities. We illustrate the strategy for a supersymmetric $t-J$ Hamiltonian in considerable detail. The impurity comprises the local deformation of the hopping and exchange integrals as well as a three-body charge-current interactions on neighboring sites. We explore the thermodynamic properties of the system at low and high temperatures, and obtain results that are beyond boundary conformal-field theory. 
P.-A. Bares