  We report measurements of the amplitude of the Aharonov-Bohm oscillations in
a mesoscopic diffusive gold ring as a function of the DC bias voltage V. The
amplitude of the h/e oscillations increases with V once the Thouless energy Ec
and thermal energy are exceeded, and decreases at higher values of V. The
increase of the amplitude is interpreted in terms of a superposition of the
statistically independent contributions of eV/Ec energy intervals, whereas its
decrease at high V could be attributed to enhanced inelastic scattering
processes.
