<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31344871</termId><termName>oxygen allotropes</termName><termType>PT</termType><termNote><![CDATA[ Forms of the chemical element oxygen that are different from each other but exist in the same physical state. ]]></termNote><termCreatedDate>2026-03-30 20:33:01</termCreatedDate><relation><relationType>UF</relationType><termId>31344872</termId><termName>oxygen allotrope</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31320550</termId><termName>oxygen, oxygen isotopes, allotropes, compounds</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31375543</termId><termName>ozone</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31375544</termId><termName>atomic oxygen</termName><termType>PT</termType></relation></term>  </Zthes>