Proximity effect between a nonsimple metal with negative U centers and a BCS superconductor (II)

According to the model of the superconducting proximity effect between a nonsimple metal thin film with negative U centers and a thin film of BCS superconductor, we have discussed the gap functions, the electronic density of states and the transition temperature T/sub c/ varying with different parameters. Results show that a small density of states due to the -U centers exists in the region of the ''energy gap.'' The transition temperature of this kind of sandwich is probably higher than the T/sub c/ of the bulk BCS superconductor within a certain range of parameters