  We investigate the Friedel oscillations in a nanowire coupled to two
macroscopic electrodes of different potentials. We show that the wave-length of
the density oscillations monotonically increases with the bias voltage, whereas
the amplitude and the spatial decay exponent of the oscillations remain intact.
Using the nonequilibrium Keldysh Green functions, we derive an explicit formula
that describes voltage dependence of the wave-length of the Friedel
oscillations.
