| 摘要 |
<p>The procedure, e.g. for marking documents or banknotes indelibly during an attempted robbery, consists of incorporating a security symbol in each document during manufacture, including an active element that is heated by electromagnetic, e.g. microwave, radiation to alter the document visibly and render it useless. The active element can be of a metal with a low melting point, a heat-sensitive glue, a polymer or capsules that release a disclosing agent when exposed to electromagnetic radiation released in an emergency.</p> |
