签字笔笔痕同一认定充分条件的分析

签字笔因其具有书写流利、使用方便的特点，是现今最常见的书写工具之一。文章根据签字笔的结构特点和笔痕特征的形成机理，结合收集的96份实验样本，首次对签字笔笔痕进行同一认定应具备的充分条件进行初步研究，探讨了书写纸张施胶程度、衬垫物软硬程度、书写人运笔力度以及书写速度等书写条件因素的具体影响，同时研究了签字笔启用初期与末期书写笔痕特征可能出现的变化问题，总结出笔痕特征反映性、稳定性和特定性的具体特点，提出书写条件与书写笔的相近书写阶段均是签字笔笔痕同一认定充分条件的重要组成部分的观点，以期对文检工作者利用笔痕特征有一定的借鉴意义。     

个人的书写习惯对签字笔笔痕的影响

笔痕特征是文检笔迹鉴定的新方式,经过多年的应用实践,获得了较突出的成绩.笔迹鉴定新采用的笔痕特征检验,解决了特定书写笔与书写人同一认定的检验技术难题,提高了对少量字及笔画、摹仿等疑难字迹的检验效率.近年来,签字笔的普遍使用,让“书写习惯对签字笔笔痕的影响”这一课题变得必要.本文重点研究个人书写习惯对签字笔笔痕的特定性和稳定性的表现,有助于掌握利用笔痕特征进行同一认定的具体规律.     

无交叉笔画状态下激光打印文字与中性笔书写文字形成时序的实验研究

目的探索无交叉笔画状态下激光打印文字与中性笔书写文字的时序特征及变化规律,以求运用于案件检验。方法以两种不同时序,请5名志愿者分别执不同中性笔在120张A4纸张上书写文字,并使用4台不同型号激光打印机打印文字,再运用奥博视频层晰显微镜对实验样本进行放大观察。结果证实在两种时序条件下制作的实验样本之间存在诸多差异性特征。结论这些差异性特征为准确判定无交叉笔画状态下激光打印文字与中性笔书写文字的时序提供了基础实验依据。     

滚珠型签字笔笔痕特征的实验研究

目的归纳总结滚珠型签字笔笔痕特征的分类,为笔迹鉴定人正确使用此类笔迹特征提供科学的参考依据。方法本研究采用科学实验的方法,对20人使用不同品牌的三支签字笔书写的笔迹进行了观察与分析。结果同一人使用不同的签字笔、不同人使用同一支签字笔和不同人使用不同的签字笔书写所形成的笔痕现象具有相同的表现。结论签字笔笔痕特征只是众多笔迹特征当中的一种,不能单独依据此类特征出具鉴定结论。     

签字笔与圆珠笔笔痕特征的比较研究

目的 探讨签字笔笔痕是否天然地适用圆珠笔笔痕检验条件而能够进行同一认定.方法 运用比较分析方法,在不同纸张条件下,以签字笔和圆珠笔为研究对象,收集288份有效实验样本,分别观察、记录、分析实验样本中的所产生的笔痕特征.结果 签字笔笔痕主要出现在大笔画的划痕特征；签字笔笔痕的稳定性和特定性要比圆珠笔弱.结论 签字笔笔痕同一认定需要考虑签字笔本身的特性,不可盲目鉴定.     

薄层色谱法鉴别黑色中性笔色痕的种类

黑色中性笔墨水主要由溶剂、色料、增稠剂、稳定剂和其他添加剂等组成,不同厂家或同厂家不同牌号中性笔墨水的成分不同,尤其是色料差别较大,这为中性笔墨水的种类鉴别提供了依据。本文利用数理统计中的均匀设计法和正交设计法安排试验,建立了一种可用于黑色中性笔色痕种类鉴别的方法:用N,N-二甲基甲酰胺作为黑色中性笔色痕的提取剂,四氢呋喃:甲醇:1,2-二氯乙烷:氯仿=30:15:5:7为展开剂的薄层色谱分析法。     

TDS-GC/MS法检测黑色中性笔墨迹中挥发性溶剂的历时性变化

目的 应用热脱附-气相色谱/质谱(TDS-GC/MS)分析,研究7支黑色中性笔墨迹中挥发性溶剂的历时性变化规律.方法 选取7支不同品牌的黑色中性笔,分别在A4纸和笔记本上进行一次制样,然后在不同时间点取样,应用所建TDS-GC/MS方法分析墨迹中乙二醇、二甘醇和三甘醇在200余天内的含量变化.结果 6支笔中的乙二醇、三...     

签字笔书写笔痕特征的实验分析

目的为准确掌握签字笔书写笔痕特征的变化规律，以求将其运用于案件鉴定。方法通过对同一人执不同签字笔、不同人执同一支签字笔及同一人执同一支签字笔书写笔痕分别进行实验分析。结果证实前二种情况下笔痕特征具有相互区别的特定性，后一种情况下笔痕特征具有重复再现的稳定性。     

步长变化对踏痕影响的比较研究

本文通过大量的实验对不同步长下步态特征中的踏痕变化情况进行统计、分析,总结步长变化与踏痕间的内在联系和变化规律特点,为利用步幅特征进行足迹定量化检验鉴定提供理论依据。     

紫外-可见光谱法研究蓝色圆珠笔色痕自然老化规律

目的论述自然老化下蓝色圆珠笔色痕中染料成分的变化规律。方法利用UV-VIS光谱对圆珠笔文字色痕中染料成分相对于铜酞菁的变化进行实验。结果得到染料与铜酞菁吸光度之比随老化时间变化的数据和曲线。结论利用UV-Vis光谱研究文件制成时间是可行的,为书写时间的鉴定拓展了思路。     

Characterization and dating of blue ballpoint pen inks using principal component analysis of UV-Vis absorption spectra, IR spectroscopy, and HPTLC

The ink of pens and ink extracted from lines on white photocopier paper of 10 blue ballpoint pens were subjected to ultraviolet-visible (UV-Vis) spectroscopy, infrared (IR), and high-performance thin-layer liquid chromatography (HPTLC). The R(f) values and color tones of the bands separated by thin-layer chromatography (TLC) analysis used to classify the writing inks into three groups. The principal component analysis (PCA) investigates the pen responsible for a piece of writing, and how time affects spectroscopy of written ink. PCA can differentiate between pen ink and ink line indicates the influence of solvent extraction process on the results. The PCA loadings are useful in individualization of a questioned ink from a database. The PCA of ink lines extracted at different times can be used to estimate the time at which a questioned document was written. The results proved that the UV-Vis spectra are effective tool to separate blue ballpoint pen ink in most cases rather than IR and HPTLC.     

Study on the Method Used to Display Self‐fading Lines and Erasable Lines

Two new kinds of writing tools are popular in China's market. One is a self‐fading pen, and another is an erasable pen. The ink of the two kinds of writing tools has a remarkable characteristic that it can gradually fade or disappear under heat or be rubbed off. How to reveal the disappeared written lines is a very important question for document examiners. In this article, three series of ink line samples were made with five types of self‐fading pens, 18 types of erasable pens, and three types of papers. Temperature, humidity, and lighting are known as influential factors of the process, and the effect of fading was examined. Luminescence, ultraviolet (UV), sidelight, electrostatic indentation development,low temperature, and solution revealing methods are found to be effective methods used to reveal the disappeared written lines. The best operating conditions for each method were obtained from the conducted experiments.     

Characteristics of erasable ball point pens

In 1979 shortly after the introduction of the erasable ball point pen two papers were published describing its basic characteristics (W.J. Flynn, J. Police Sci. Adm., 7 (1979) 346–349; P. Pfefferli and J. Mathyer, Rev. Int. Criminol. Police Tech., (1979) 407–419). Since that time two additional makes of pens and other colors of ink have been introduced, and the quality of writing has been significantly improved.The ink of the erasable pen differs significantly from that of the standard ball point pen, and for that matter from ink of all other modern day pens. In what way might this newer pen produce a written line different from other ball point pens? This is one question that the paper addresses with limited success.When erased, what techniques can be used to attempt to determine the text of the original writing? The writer considers all standard methods for deciphering erased writing and discusses modification by use of infrared film with oblique light photography — the method most successful in determining the original contents of the erasure.     

Determination of Changes in Crystal Violet and Phenoxyethanol (Dating Ink)

Ink dating is a significant problem in terms of forensic science. Ballpoint pens are generally used as writing tools on the documents. Aging is determination of the changes in dyes and solvents in the composition of ink over time by analytical methods. The evaporation of the solvents from the paper surface is faster than the decomposition process of the dyes. In this study, in 2017, we were asked by the court to determine whether the texts on the suspicious pages of an agenda dated 1996 were written within 2 years or earlier. Phenoxyethanol and dyes were examined in the composition of all suspected ink samples. The results show the determination of both the decomposition process of the dyes and the evaporation process of phenoxyethanol in the aging of the document entries written by ballpoint pen.     

基于银胶表面增强拉曼光谱检验蓝色书写字迹初探

目的用基于银胶的表面增强拉曼光谱技术检验蓝色签字笔字迹。方法取4种常见不同牌号的蓝色签字笔在其字迹上滴加微量银胶,用显微共焦拉曼光谱仪进行检验。结果不同品牌的蓝色签字笔字迹的表面增强拉曼光谱不同。结论基于银胶的表面增强拉曼光谱技术可用于纸张上蓝色签字笔字迹的检验。     

写字机器人伪造签名字迹的鉴别

目的通过实验研究使用写字机器人伪造的签名字迹特征,减小文件检验鉴定中的错判风险。方法以真实书写字迹为模板、使用市面上主流款式的写字机器人执不同种类书写笔进行书写,通过直接观察、显微观察、反射变换成像(RTI)方法观察等方式比对手写字迹和机器人书写字迹的差异,归纳写字机器人伪造字迹的主要特征,总结出有效的检验鉴别方法。结果通过研究发现写字机器人伪造签名笔迹的特点主要有起收笔为顿压笔,笔画出现细微的抖动歪曲现象,整体笔画笔压均匀,运笔生硬无笔势等。结论目前写字机器人伪造签名字迹与真实手写字迹还有一定差异,使用反射变换成像(RTI)方法观察能达到较好的检验效果。