求翻译：Mono metal ion (Eu3+, Tb3+, Ce3+, Y3+, Zn2+, Cd2+, Cu2+) exchanged zeolite, rare-earth ion (Eu3+, Tb3+, Ce3+) exchanged zeolite modified with Y3+ and rare-earth ion (Eu3+, Tb3+, Ce3+) exchanged zeolite modified with Zn2+ are discussed here.是什么意思？