几种墨水材料的检验

墨水是书写文字的常用材料,其种类很多。根据化学成分及用途的不同,可分为蓝黑墨水、染料墨水、碳素墨水及其他墨水。在侦查工作中时有遇到用该种书写材料涂抹掩盖等情况,故此,墨水材料的检验鉴定,在侦破此类案件中起着十分重要的作用。     

测量笔画增宽度判断激光打印文件朱墨时序初探

目的考察印章印文与激光打印字迹交叉部位的笔画增宽现象,得到朱墨时序判断依据。方法制作两种朱墨时序的实验样本,在VSC-6000文检仪下观察,读数显微镜在相同放大倍率测量,记录增宽度,比较同种品牌印文色料在两种时序下笔画的增宽度。结果相同保存条件下同种品牌印文色料不同时序盖印的实验样本都有增宽现象,先墨后朱时序下增宽度较大。结论该方法可以作为朱墨时序判断依据。     

Forensic Identification of Seal Oils Using Lipid Profiles and Statistical Models

Seal blubber oils are used as a source of omega‐3 polyunsaturated fatty acids in Canada but prohibited in the United States and (FA) European Union. Thus, a reliable method is needed to identify oils originating from seals versus fish. Two lipid profiling methods, fatty acid analysis using gas chromatography and triacylglycerol (TAG) analysis using liquid chromatography and mass spectrometry, were applied with statistical models to discriminate commercial oils and blubber samples harvested from marine fish and seals. Significant differences were observed among FA profiles, and seal samples differed from each of the fish oils (p ≤ 0.001). FA and TAG profiles were used to discriminate sample groups using a random forest classifier; all samples were classified correctly as seals versus fish using both methods. We propose a two‐step method for the accurate identification of seal oils, with preliminary identification based on FA profile analysis and confirmation with TAG profiles.     

喷墨打印墨水分析技术的回顾及展望

文章介绍了常用的喷墨打印机及喷墨打印墨水的发展概况、喷墨打印墨水的主要成分及近年来分析技术的进展情况。喷墨打印墨水中的着色剂主要用色度法、紫外光谱法、漫反射红外光谱法、喇曼光谱法、TLC法、HPLC法分析,而其中的溶剂成分主要用GC/MS及顶空GC/MS法分析。     

论自然人签章的民法意义

签章是指某一自然人在民事法律性文件上签名或加盖印章或者签名并加盖印章的行为。其作用在于：一是“要式”作用;二是证据作用。自然人签章会发生在不同的场合,并且,随着签章人担任的社会角色的变化,其法律上的身份不尽相同,签章的法律效力也因此而有区别。故对于签章所产生的法律后果,必须结合签章行为人在某一具体法律关系中的法律身份才能加以界定。签名与盖章不能混为一谈,两者不能在法律上划等号,依据现行立法,一般而言,签名与盖章有同等的法律效力。当事人可以签名,也可以盖章代替签名。但法律有特别规定的,二者就有了严格的区别,不能相互替代。自然人签章存在的问题,一是立法上的。二是法律适用上的。对于问题的解决,笔者的建议是：完善有关签章的相关立法,做好法律宣传。     

多次测定法确定蓝色圆珠笔字迹形成时间

通过研究相隔一定时间的多次测定数据的变化规律与书写时间的内在关系，建立了部分近期书写的圆珠笔字迹形成时间的检验方法，确定了相隔一定时间的两次测定数据的变化规律与书写时间内在关系的判定阀值。形成了无需对照样本即可判定部分圆珠笔字迹是否近期书写的检验方法。     

谈利用假印章、假挂失诈骗银行案件的特点及对策

随着我国经济的发展,诈骗银行冒领存款的案件逐渐增多。文章结合实际案例对利用假印章采取转账支票转款及利用冒名挂失解挂取款进行诈骗的作案手段进行了详细剖析,并就如何防范提出对策及建议,以供有关部门及工作人员在实际工作中借鉴。     

国产圆珠笔油墨字迹书写时间的鉴别

对国产圆珠笔油墨字迹书写时间的鉴别进行了实验研究,达到了检测速度快,实用性强,费用低的效果.     

Dating of Iron Gall Ink Using the Dissolution‐Diffusion Method

In many criminal and civil cases, some questioned documents are written with iron gall ink. Determining the date when an iron gall ink entry was written can be important to assess the authenticity of a document. A dissolution‐diffusion method was successfully employed to draw aging curves of iron gall ink entries stored in controlled conditions over 40 months. Calibration curves were created to indicate the relationship between the average dissolution‐diffusion rate of ink components and the age of ink entries stored under natural aging conditions. As preliminary findings of this study, the mixed solution of dimethyl formamide (DMF) and anhydrous ethanol was suitable to dissolve the dye of iron gall ink strokes made at different time. It was also determined that brands of iron gall inks, types of paper, and thickness of iron gall ink strokes had varying impacts on estimating the dates of iron gall ink strokes.     

Ink Dating Using Thermal Desorption and Gas Chromatography/Mass Spectrometry: Comparison of Results Obtained in Two Laboratories

An ink dating method based on solvent analysis was recently developed using thermal desorption followed by gas chromatography/mass spectrometry (GC/MS) and is currently implemented in several forensic laboratories. The main aims of this work were to implement this method in a new laboratory to evaluate whether results were comparable at three levels: (i) validation criteria, (ii) aging curves, and (iii) results interpretation. While the results were indeed comparable in terms of validation, the method proved to be very sensitive to maintenances. Moreover, the aging curves were influenced by ink composition, as well as storage conditions (particularly when the samples were not stored in “normal” room conditions). Finally, as current interpretation models showed limitations, an alternative model based on slope calculation was proposed. However, in the future, a probabilistic approach may represent a better solution to deal with ink sample inhomogeneity.