<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31321908</termId><termName>electron tubes</termName><termType>PT</termType><termNote><![CDATA[ Refers to devices used to amplify or otherwise modify electrical current via the flow of electrons in an evacuated glass tube or bulb. ]]></termNote><termCreatedDate>2026-03-30 20:26:47</termCreatedDate><relation><relationType>UF</relationType><termId>31321911</termId><termName>electron tube</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321912</termId><termName>electronic valve</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321913</termId><termName>electronic valves</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321914</termId><termName>thermionic valves</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321915</termId><termName>valve</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321916</termId><termName>valve, thermionic</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321917</termId><termName>valves</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321909</termId><termName>audion</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31321910</termId><termName>audions</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31306852</termId><termName>electrical system components</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31346863</termId><termName>diodes</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31346865</termId><termName>vacuum tubes</termName><termType>PT</termType></relation></term>  </Zthes>