  The scaling behavior of Anderson impurity models each of which with a
different site energy epsilon_i is examined close to the Mott-Anderson
transition. Depending on the impurity energy epsilon_i, in the critical regime
the site turns into a local magnetic moment, as indicated by a vanishing
quasiparticle weight Z -> 0, or remains nearly doubly occupied or nearly empty,
corresponding to Z -> 1. In this paper, we present the scaling behavior of Z as
a function of the on-site energy epsilon_i and the distance t to the
transition, and interpret our result in terms of an appropriate beta function
beta(Z).
