Fusion cross sections for superheavy nuclei in the dinuclear system concept

Using the dinuclear system concept we present calculations of production cross sections for the heaviest nuclei. The obtained results are in a good agreement with the experimental data. The experimentally observed rapid fall-off of the cross sections of the cold fusion with increasing charge number $Z$ of the compound nucleus is explained. Optimal experimental conditions for the synthesis of the superheavy nuclei are suggested.Comment: 16 pages, LaTeX, including 3 postscript figure

Shell Corrections of Superheavy Nuclei in Self-Consistent Calculations

Shell corrections to the nuclear binding energy as a measure of shell effects in superheavy nuclei are studied within the self-consistent Skyrme-Hartree-Fock and Relativistic Mean-Field theories. Due to the presence of low-lying proton continuum resulting in a free particle gas, special attention is paid to the treatment of single-particle level density. To cure the pathological behavior of shell correction around the particle threshold, the method based on the Green's function approach has been adopted. It is demonstrated that for the vast majority of Skyrme interactions commonly employed in nuclear structure calculations, the strongest shell stabilization appears for Z=124, and 126, and for N=184. On the other hand, in the relativistic approaches the strongest spherical shell effect appears systematically for Z=120 and N=172. This difference has probably its roots in the spin-orbit potential. We have also shown that, in contrast to shell corrections which are fairly independent on the force, macroscopic energies extracted from self-consistent calculations strongly depend on the actual force parametrisation used. That is, the A and Z dependence of mass surface when extrapolating to unknown superheavy nuclei is prone to significant theoretical uncertainties.Comment: 14 pages REVTeX, 8 eps figures, submitted to Phys. Rev.

From Joint Activity to the Construction of New SocialCommunities: Jointness. Creativity. Education. School (Roundtable of the methodological seminar supervisedby V.V. Rubtsov and B.D. Elkonin)

On July 10, 2018 a discussion seminar “From Joint Activity to the Construction of New Social Communities: Jointness. Creativity. Education. School” was held at the Moscow State University of Psychology and Education dedicated to the 70th birthday of professor Vitaly Rubtsov, Rector of MSUPE. Some of the discussed topics were: “Sociogenesis and the productive nature of joint action”, “From co-operation to co-creation: new forms of community in joint activity”, “Jointness in play, learning and design activity”, “School as the place for developing various forms of child-adult communities and activities”. Among the participants of the seminar were representatives of the leading research and educational organizations: Moscow State University of Psychology and Education, National Research University Higher School of Economics, Psychological Institute of the Russian Academy of Education, Institute of Philosophy of the Russian Academy of Sciences, and others. Here we present the full text of the discussion