<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31375543</termId><termName>ozone</termName><termType>PT</termType><termNote><![CDATA[ An allotropic form of oxygen, O3, which is a bluish toxic gas with a characteristic sharp odor, is a powerful oxidizing agent, and is produced from molecular oxygen by electrical discharge and in the upper atmosphere by ultraviolet light. ]]></termNote><termCreatedDate>2026-03-30 20:41:17</termCreatedDate><relation><relationType>BT</relationType><termId>31344871</termId><termName>oxygen allotropes</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31304793</termId><termName>ozonation</termName><termType>PT</termType></relation></term>  </Zthes>