Electrons and muons in extensive air showers of energies E-0 >= 3 x 10(17)eV: Yakutsk array data and QGSJET model

The results obtained from an analysis of the 1974-1998 Yakutsk array data o n muons with threshold energy E-mu approximate to 1.0 x sec theta GeV and o n all charged particles (electrons and muons) in extensive air showers (EAS ) art: reported and compared with the results of calculations based on the model of quark-gluon strings with jets. For energies of E-0 less than or eq ual to 3 x 10(18) eV and zenith angles of theta less than or equal to 45 de grees, the results of the model calculations are: consistent with the measu red properties of the showers, while, for higher energy EASs, there are con siderable discrepancies, which are probably due to the change in the develo pment of the shower cascade in the region E-0 greater than or equal to 3 x 10(18) eV. (C) 2000 MAIK "Nauka/Interperiodica".