TY JOUR TI Features of adaptation of younger adolescents during the transition from primary school to basic school general education KW schoolchild KW younger teenager KW adaptation KW maladjustment KW conditions for effective adaptation of students KW psychological and pedagogical support of the educational process JO Scientific notes of P. F. Lesgaft University AU Stepchenko, T.A. AU Savin, A.V. AU Seraya, G.V. AU Simukova, S.V. PY 2025 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft