TY JOUR TI STUDY OF THE STRUCTURE AND OPTICAL DENSITY OF POLYIMIDE TRACK (NUCLEAR) MEMBRANE KW polyimide membranes KW heavy ions KW chemical etching KW optical density KW contact angle KW surface morphology JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Cherkashina, N.I. AU Pavlenko, Z.V. AU Manaev, V.A. AU Samoilova, E.S. AU Sidelnikov, R.V. PY 2020 IS 5 PB Belgorod State Technological University named after V.G. Shukhov