???? ??????? ???? metatungstate ??? ???? ????? ???, ??? ?? 4xy. ??? 4 (?????? ????), ?????? ?????? ????? ??????? ?? ??? ???? ????? ????? ?? ????? ???? ????????? ?????;
x: ?????? ???? (??? ?????);
y: ?????? ???? (??? ????).

???????? ????? ??????? ????? ?? ??? ??????? ?????????? ????? ????? ?????? ?? ????? ??????? ?? ????? ??? ???? ????????. ????? ?????? ???? ???? ?? ????? ?? ????? ?????? ????? ?????.

"????????? ?????? ?? ???? ????????? ????? ??? ????? ??? ????" (????? ????? ?? ???? ?? ?? '219) ???? ?? ????? ??? ?????? ??????? ?????? ?? ????? ????? ?? ?? ??? ?????? ????, ?????, ??????, ????? ?????, ????? ???? ?? ???? ???? ????? ?? ??????? ????????, ????? ????? ????, ??????.

??? ?????, ????? ????, ?????? ??? ??????? ????????? ???? ????? ????????? ??? ?????. ????? ??, ??? ??? ??? ???? ????? ???? ????? ??? ?????? ??? ???? / ???? ?? ????. ?? ??? ??? ????? ?????? ????? ?????? ?? ?????? ???? ??????? ???? ???? ?????? ??? ????? ?? ????? ?????? ????? ???????? ????? ??? ???? ???, ???? ??? ???? ???????? ????????? ???? ?????? ?? ?????? ???? ??????? ????. ??? ??? ???? ???? ??????? ???? ?? ??, ????? ?? ????? ????? ????? ?????? ????? ???? ???? ???????? ??? ?? ???? ?????, ????? ?????? ???? ?????? ?????? ?????? ???? ???? ??????? ???? ??? ????? ?????.