显微共聚焦激光拉曼光谱技术鉴别假币上的光变油墨  

Micro Confocal Raman Spectroscopy Identifying Types of Optically Variable Ink from Counterfeit Note

作　　者：白萃萃[1] 梁鲁宁 粱思禹 刘进[1] 朱毅 BAI Cuicui;LIANG Luning;LIANG Siyu;LIU Jin;ZHU Yi(Forensic Science Department,Jiangsu Police Institute,Nanjing 210031,China;Institute of Forensic Science,Ministry of Public Security,Beijing 100038,China;Insititute of Criminal Science and Technology,Shanghai Xuhui Pubilc Security Sub-bureau,Shanghai 200231,China)

机构地区：[1]江苏警官学院刑事科学技术系,南京210031 [2]公安部鉴定中心,北京100038 [3]上海市徐汇公安分局刑事科学技术研究所,上海200231

出　　处：《刑事技术》2022年第5期477-482,共6页Forensic Science and Technology

基　　金：江苏警官学院院级项目(2015SJYZQ03)。

摘　　要：目的尝试利用显微共聚焦激光拉曼光谱技术鉴别假币上的仿冒光变油墨。方法收集77张不同假币制造窝点不同印刷版型的假币,建立最佳实验条件,将所得谱图进行小波变换降噪、非对称最小二乘法基线扣除、数据归一化等一系列预处理,提取出每张假币上光变油墨所包含的拉曼位移峰信息。结果拉曼谱图中拉曼位移峰与色料成分有关,由此可将假币上的仿光变油墨分为三类:一类检出酞菁铜颜料,一类检出酞菁铜和钛菁绿两种颜料,一类则未检出拉曼位移峰。由于假币纸张选用的不同,造成拉曼谱图中部分拉曼位移及荧光背底的差异,故如果结合纸张影响,可将第一类假币票样分为五大类。结论显微共聚焦激光拉曼光谱技术不但可以通过拉曼位移的不同鉴别假币,且可根据拉曼位移及强度进一步推断造假手段的差异,为假币溯源提供依据。The Optically Variable Ink(OVI)can change its color from one to another at different angles observed onto the RMB’s 5th-edition banknotes,e.g.,the 100-denomination one.Here,micro confocal Raman spectroscopy was trial to identify the mimic-OVI ink of counterfeit 100-denomination RMB notes.With 77 edition-various counterfeit 100-denomination RMB notes seized from different dens,the optimal test condition was set up so that the Raman spectra were collected from the seized counterfeit notes,followed to have them undergone into serial preprocessing of wavelet-transform denoising and realization,asymmetric least-square baseline deduction and spectral normalization.Such the above tackling measures extorted every tested counterfeit note to deliver its eigenvalues from whole Raman spectra of OVI.Consequently,Raman shift peak was found to correlate with the ingredients of pigment,thus having the counterfeit-note mimic-OVI divided into three sorts:the one containing copper(Ⅱ)phthalocyanine pigment;the one including both the copper(Ⅱ)phthalocyanine pigment and polychlorinated copper phthalocyanine pigment;and the one having no Raman shift.The different paper used with counterfeit note was able to make Raman shifts and fluorescent backgrounds further diverse,hence having additional five classifications brought into the sort 1 counterfeit notes.Accordingly,micro confocal Raman spectroscopy could be a potential tool not only for identification of counterfeit RMB notes based on the different Raman shifts but also for recognition of discrepant counterfeiting means according to dissimilar Raman shifts and intensities,therefore capable of providing basis to track the source/den of counterfeiting note.

关 键 词：文件检验 显微共聚焦激光拉曼光谱技术 光变油墨 伪造百元人民币 溯源 

分 类 号：DF794.3[政治法律—诉讼法学]