正交法优化分析蓝色圆珠笔油墨的缓冲体系

用正交设计法对硼砂、十二烷基硫酸钠(SDS)和乙腈组成的缓冲体系及其酸度进行了优化.实验结果表明,该体系作为毛细管电泳分析蓝色圆珠笔油墨缓冲运行液的最佳配比为55mmol/L硼砂～40mmol/LSDS溶液和40%(V/V)的乙腈,溶液为pH9.3.     

几种朱墨交叉时序的检验方法及其比较分析

文件朱墨交叉时序的确定一直是困扰文检界的难题之一.本文简要介绍了目前常用的六种检验方法,并结合五个典型案例对各种检验方法进行比较分析,以探讨针对不同形成条件的文件物证进行检验时采用哪些检验方法更为有效的解决问题.希望能够在同类问题的研究上达到抛砖引玉的效果.     

An examination of the sequence of intersecting lines using attenuated total reflectance-Fourier transform infrared spectral imaging

In this study, the potential of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectral imaging as a technique to determine the sequence of line crossings was examined. The technique was successful in determining the sequence of heterogeneous line intersections produced using ballpoint pens and laser printers. By imaging at characteristic frequencies, it was possible to form spectral images showing the spatial distribution of the materials. By examining the spectral images from the inks, it was possible to determine whether the ink was above or below the toner. In blind testing, ATR-FTIR spectral imaging results were directly compared to those obtained by eight experienced forensic document examiners using methods regularly employed in casework. ATR-FTIR spectral imaging was shown to achieve a 100% success rate in the blind tests, whereas some incorrect sequence determinations were made by the forensic document examiners when using traditional techniques. The technique was unable to image ink-jet printing, gel pens, roller ball pens, and felt-tip pens, and was also unable to determine the sequence of intersecting ballpoint pen lines.     

Hair and fingernail gadolinium ICP-MS contents in an overdose case associated with nephrogenic systemic fibrosis

The recovery of erased identification marks is a problem for the forensic scientist, particularly with respect to vehicles and firearms. The widely accepted procedure for steel imprints is to use Fry's reagent. The present study examined the possibility of forming a paste that may be easier to use. The paste proved to be as effective as liquid in most cases, and often gave better results. The ease of using the paste gives it distinct advantages over liquid reagent.     

胶带粘面手印荧光显现剂的研发与应用

目的根据胶带粘面上潜在手印的特点,利用染料和潜手印的理化性质,研究开发胶带粘面手印荧光显现剂。方法在各种胶带粘面上显现潜在手印,并与常规的碳素墨水染色法进行比较。结果在长波紫外线照射下手印呈黄色明亮荧光,手印纹线清晰、连贯,基本不受手印遗留时间、客体表面颜色和性质的影响。结论胶带粘面上的汗潜手印和血潜手印用荧光显现剂显现效果优于碳素墨水染色法,在实际案件的侦破中有较好的应用前景。     

An Examination of the Sequence of Intersecting Seal and Laser Printing Toner Line

Examining the sequence of intersecting seal and laser printing line is a significant method of determining the authenticity and validity of documents. In this study, five brands of stamp pad inks, three types of inkpads and seven kinds of laser printers were used to make heterogeneous line intersections. Observation method of physical characteristics, scraping technique and fluorescence method was used to determine the sequence of intersecting lines. Distinguishing features were noted between the materials produced in both sequences. As the results obtained from the study were positive, these features might provide a scientific basis for accurately determining the sequence between laser printing line and inkpad (stamp pad ink) seal.     

印章防伪技术探析

印章防伪技术包括印痕防伪和印泥印油防伪,其中印泥印油防伪技术是印章防伪技术很重要的一个方面。目前在国内印泥印油防伪只限于荧光加密防伪,已不能从根本上达到防伪的目的。运用多色反光材料、有机物质和印泥,进行精工合成的新型防伪印泥以良好的性能保持印泥的本质不变,又能在印文中显现出不同颜色和不同大小的反光点,可以判断文件制成时间,有很好的防伪效果。     

水平ATR法无损检验纸张上的印油

文章利用傅里叶变换红外光谱中的衰减全反射（水平——ATR）技术无损测定了纸张上的10种红色印油,根据其红外光谱的特征吸收,可将10种印油分为2大类7种。该技术具有快速、准确和不破坏样品等特点,为印油的检验提供了一种适用的检测方法。     

数字证据完整性证明方法研究——安全的、可供审计的数字时间戳证明方法

在数字案件和数字纠纷案件中,数字证据往往成为再现案情、化解纠纷的关键。但数字证据的脆弱性、易毁损性等特点决定了数字证据的完整性难以保障,因而形成了数字证据采信难的问题。在比较研究现有的数字证据完整性证明方法优缺点的基础上,以数字签名技术为支撑的一种数字证据完整性证明的新方法——安全的、可供审计的数字时间戳证明方法,对数字证据的收集、保存分析及传递等取证环节大有帮助。     

Prepared Disappearing Ink and Deciphering of Documents

Disappearing inks can be used for forgeries in many fields. In this study, thymolphthalein indicator solution was prepared as a disappearing ink. A total of 54 different solutions containing thymolphthalein were prepared at six different concentrations and nine different pH values. Among the prepared solutions, 0.16 g/50 mL and 0.32 g/65 mL thymolphthalein at pH 14 were the optimum solutions that were not distinguishable from regular ink when applied to promissory note. Fountain pens were filled with the abovementioned ink solutions and applied to promissory notes for experimental purposes. After 40 h, ink residues were not visible on promissory notes written with the ink with the optimum pH (pH = 14) value. To decipher the entries that disappeared, an instrumental method (Video Spectral Comparator‐8000) and a chemical method (using NH₃ vapor) were used, succeeded at 0.32 g/65 mL, but failed at 0.16 g/50 mL thymolphthalein. Therefore, NH₃ had to be sprayed for 0.16 g/50 mL with negligible harm.