<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31361794</termId><termName>x-ray optics</termName><termType>PT</termType><termNote><![CDATA[ Branch of optics that uses x-rays instead of visible light, concerned with focusing and otherwise manipulating x-rays beams for use in analysis. Since x-rays are strongly absorbed by solid matter, the optics used in the visible and near-infrared portions of the electromagnetic spectrum cannot be used to focus or reflect the radiation. ]]></termNote><termCreatedDate>2026-03-30 20:37:37</termCreatedDate><relation><relationType>UF</relationType><termId>31361795</termId><termName>optics, x-ray</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31327497</termId><termName>optics</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31402863</termId><termName>polycapillary optics</termName><termType>PT</termType></relation></term>  </Zthes>