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确定文件形成时间的几种新方法 总被引:2,自引:0,他引:2
本文概要介绍了判断书写时间技术在八、九十年代的重要进展,并介绍了几种确定文件形成时间的新方法:热分析法、X光电子能谱法、显微分光光度法、溶剂蒸溶法。 相似文献
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A comparison is made of proprietary methods to develop latent fingerprint deposits on the inked side of thermal paper using either chemical treatment (Thermanin) or the application of heat to the paper (Hot Print System). Results with a trial of five donors show that the application of heat produces statistically significantly more fingerprint ridge detail than the chemical treatment for both fingerprint deposits aged up to 4 weeks and for a nine sequence depletion series. Subjecting the thermal paper to heat treatment with the Hot Print System did not inhibit subsequent ninhydrin chemical development of fingerprint deposits on the noninked side of the paper. A further benefit of the application of heat is the rapid development of fingerprint deposits (less than a minute) compared with up to 12 h for the Thermanin chemical treatment. 相似文献
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Roberto Rosa Ph.D. Paolo Veronesi Ph.D. Cristina Leonelli Ph.D. 《Journal of forensic sciences》2013,58(5):1314-1321
The thermal development of latent fingerprints on paper surfaces is a simple, safe, and chemicals‐free method, based on the faster heating of the substrate underlying the print residue. Microwave heating is proposed for the first time for the development of latent fingerprints on cellulose‐based substrate, in order to add to the thermal development mechanism the further characteristic of being able to heat the fingerprint residues to a different extent with respect to the substrate, due to the intrinsic difference in their dielectric properties. Numerical simulation was performed to confirm and highlight the selectivity of microwaves, and preliminary experimental results point out the great potentialities of this technique, which allowed developing both latent sebaceous‐rich and latent eccrine‐rich fingerprints on different porous surfaces, in less than 30 sec time with an applied output power of 500 W. Microwaves demonstrated more effectiveness in the development of eccrine‐rich residues, aged up to 12 weeks. 相似文献
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建设社会主义新农村,是党和国家做出的具有深远意义的重大战略部署,积极推进现代农业建设,则是这一战略的重要组成部分。吉林省作为农业大省应始终坚持把现代农业建设作为社会主义新农村建设的着力点和首要任务,结合省情加大对现代农业的投入力度,调整产业结构,强化产业支撑,提高农民素质,进而提升农村经济发展的整体水平。 相似文献
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A calibration test is described for monitoring the operation of equipment used to develop latent fingerprints on thermal paper by the application of either controlled or uncontrolled heat. A working solution of a water/glycerol emulsion and butylene glycol is applied to thermal paper by means of either a vinyl stamp and pad, or a marker pen. Varying the amount of butylene glycol enables the thermal paper to change color at different temperatures between approximately 40 and 60°C, which is below the normal color change temperature of the paper. The described test may be used to verify the correct operation, at different temperatures, of a controlled heat source during and after fingerprint development (such as the Hot Print System) or to monitor the paper temperature with an uncontrolled heat source (such as a warm air blower), thereby avoiding unintentional coloring of the entire paper surface. 相似文献
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Abstract: Solvent evaporation caused by aging from ballpoint inks was measured by gas chromatography/mass spectroscopy (GC/MS). The sample preparation was carried out with two different thermal desorption systems. The results are compared. Thirteen inks were classified with regard to their solvents, polymers, and additives. The variation of the aforementioned compounds caused by aging was monitored for naturally and artificially aged samples. In this paper, the results are compared and discussed with respect to forensic casework. 相似文献