  Deep inelastic scattering in $^{154}$Sm+$^{160}$Gd at energies above the Bass
barrier is for the first time investigated with two different microscopic
dynamics approaches: improved quantum molecular dynamics (ImQMD) model and time
dependent Hartree-Fock (TDHF) theory. No fusion is observed from both models.
The capture pocket disappears for this reaction due to strong Coulomb repulsion
and the contact time of the di-nuclear system formed in head-on collisions is
about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of
fragments in the deep inelastic scattering process is predicted with the
simulations of the latest ImQMD-v2.2 model together with a statistical code
(GEMINI) for describing the secondary decay of fragments. More than 40
extremely neutron-rich unmeasured nuclei with $58 \le Z\le 76$ are observed and
the production cross sections are at the order of ${\rm \mu b}$ to mb. The
multi-nucleon transfer reaction of Sm+Gd could be an alternative way to
synthesize new neutron-rich lanthanides which are difficult to be produced with
traditional fusion reactions or fission of actinides.
