EP1044714A1 EP20000400930 EP00400930A EP1044714A1 EP 1044714 A1 EP1044714 A1 EP 1044714A1 EP 20000400930 EP20000400930 EP 20000400930 EP 00400930 A EP00400930 A EP 00400930A EP 1044714 A1 EP1044714 A1 EP 1044714A1 Authority EP European Patent Office Prior art keywords oxygen gas cations means exchanged Prior art date Legal status (The legal …
