  In multifragmentation of hot nuclear matter, properties of fragments embedded
in a soup of nucleonic gas and other fragments should be modified as compared
with isolated nuclei. Such modifications are studied within a simple model
where only nucleons and one kind of heavy nuclei are considered. The
interaction between different species is described with a momentum-dependent
two-body potential whose parameters are fitted to reproduce properties of cold
isolated nuclei. The internal energy of heavy fragments is parametrized
according to a liquid-drop model with density and temperature dependent
parameters. Calculations are carried out for several subnuclear densities and
moderate temperatures, for isospin-symmetric and asymmetric systems. We find
that the fragments get stretched due to interactions with the medium and their
binding energies decrease with increasing temperature and density of nuclear
matter.
