|  |   |       e
 
 
 
  
 
 


, 118, . 5, . 1099 ( 2000)
( - JETP, Vol. 91, No 5, p. 952, November 2000 on-line www.springer.com )

,
.., ..

: 14 2000

PACS: 42.50.-p, 42.79.Nv

, .