<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31343501</termId><termName>cerium</termName><termType>PT</termType><termNote><![CDATA[ Metallic element having symbol Ce and atomic number 58; a gray, ductile metal, a lanthanite, cerium is the most abundant of the rare-earth group.  ]]></termNote><termCreatedDate>2026-03-30 20:32:38</termCreatedDate><relation><relationType>UF</relationType><termId>31343502</termId><termName>Ce</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31319740</termId><termName>elements</termName><termType>PT</termType></relation></term>  </Zthes>