?. ?-?r?t?-n-r?, ?. ?. , ?. ??-???-?-t, ?. , ?. et al., ? t?r?s ?? t?? ??ts??? ? ??r ? ??t? s?t ???r? d = 20 ??? m = 4 ???????r?s??s ??? r??t ?s???t???s t?? ??r??? ??st ??r??r? ?s r?????? t?? s??? ?? ??? t?? ?rr????? ???ts ?? t?? t?st s??t?? ??? ?s???t??? t??? ??r r?