  The effects of a non-magnetic Zn impurity substituting an in-plane Cu are
studied by solving the Bogoliubov-de Gennes equation self-consistently which is
derived from the \ttju Hamiltonian with all the allowed order parameters
included. The Zn impurity, modeled in terms of a potential scatterer in unitary
limit, induces local staggered magnetic moments around itself, and the
calculated NMR shifts from the induced moments are in agreement with the
experimental Cu NMR spectra. We also note that the experimentally observed
negative slope of the tunneling conductance can result from the next-nearest
hopping $t'$.
