HTSC ANOMALIES AS RESULT OF THE SPECIAL ELECTRON SPECTRUM .3. DOPING INFLUENCE ON TRANSPORT AND SUPERCONDUCTING PROPERTIES

The influence of doping-induced variations of electron structure on tr ansport and superconducting properties of La2-xSrxCuO4 and Nd2-xCexCuO 4 is considered. hi the frames of proposed model the dependence of Hal l resistance on concentration x of doping element is obtained. It is s hown that in Nd2-xCexCuO4 just at x=0.15 the ''negative-U centers'' ar ises at the top of valence band and the dielectric-metal transition ta kes place. The superconductivity in Nd2-xCexCuO4 occurs in hole-conduc tive phase. The pressure dependence of T(C) in HTSC is considered.