| 摘要 |
A mixture of isotopes is provided which may be embedded into an article such as a motor vehicle, software or other articles so that they may be detected by a Geiger counter or other emission detector for identification purposes as well as to provide a chronological record of the article according to the half-lives of the isotopes chosen for the mixture. The isotopes should be chosen having regard to half-lives of the order of time of the life of the article. |
