| 摘要 |
PCT No. PCT/GB87/00239 Sec. 371 Date Jan. 22, 1988 Sec. 102(e) Date Jan. 22, 1988 PCT Filed Apr. 7, 1987 PCT Pub. No. WO87/06197 PCT Pub. Date Oct. 22, 1987.An article comprising a substrate having markings which are provided by at least two fluorescent materials which have different excitation spectra in the ultraviolet region of the spectrum and different emission spectra in the visible region of the spectrum. The invention also provides a method of marking an article for identification. |
