利用印章印文可变性印迹特征鉴别印文盖印时间

文件上印章印文可变性印迹特征通常表现为印文上的异物印迹,文字线条的断线、露白,印文边框的缺损,浓重的印泥(油)点或团块,以及原子印章的套框、支撑爪的印迹等。根据印章的印面结构和印面附着物的变化规律,通过被检验印文与该印章印文的历时样本的比较检验,以印文的可变性印迹特征的异同,推断被检验印文的盖印时间。1利用印面结构不可逆变化特征鉴别印文盖印时间印面结构的不可逆变化的特征,主要表现为印面结构的缺损、磨损特征。这类特征从无到有,由少到多,发展到不同的变化程度,标志印章印面的不同变化阶段。它的异同一般可以界定盖印的…     

原子印章及其检验

原子印章印文特征(1)印文字体标准规范。主要是宋体、仿宋体个人印章有隶书体。(2)印文笔画、边框线条粗细,可有变化。因储墨垫具有一定弹性,捺印时压力大,印文线条粗,压力小,印文则细。(3)印文印色长期同质同色。(4)印文字间距离、角度等量。原子印章利用计算机制作章稿,因此字间距离、角度受计算机定格制约(除拼贴版)。(5)印文周围易出现印章托壳沾染印色残迹或压痕。因印章托壳内壁与储墨垫间隙很小,储墨垫上的印油很容易沾染到托壳上,捺印时托壳首先触及纸张为支撑,随即纸张也被托壳的沾染色沾染。用力大、衬垫物厚,易因压力作用留下压痕。(6)公章印文的星标中心部位无异迹。计算机制版克服了雕刻印章受雕刻材料及刀法工艺的限制所造成的螺纹及刀线留迹。(7)印文笔画间隙内不易被印油或灰尘粘堵。因原子印章印     

“同版“印章的实验研究

制作了13枚"同版"渗透型印章和激光雕刻印章,分析了这些"同版"印章的印面特征和盖印印文特征.研究发现,相同条件下制作的"同版"印章的个体差异十分微小,如果考虑到各种盖印条件下,这些印章盖印印文特征的变化范围,"同版"印章印文的检验是十分困难的,甚至是不可能的.     

同源性机雕渗透印章印文鉴别方法

目的寻找同源性机雕渗透印章印文间的特征差异,探索检验鉴定此类印章印文的方法。方法制作了9枚同源性机雕渗透印章并盖印大量的印文样本,通过文检仪、显微镜等仪器观察分析印文特征。结果找出了同源性机雕渗透印章印文间的细节特征差异。结论同源性机雕渗透印章虽规格性特征符合好,但仍旧可以区分,检验鉴定要以细节特征比对为主。     

同源激光雕刻橡塑印章印文的鉴别方法

目的找出同源激光雕刻橡塑印章印文之间的特征差异,建立检验鉴定此类印章印文的鉴别方法。方法制作14枚同源激光雕刻橡塑印章,借助文件仪、显微数字分析仪等仪器观察分析其盖印的印文样本。结果找出了各种细节特征差异。结论同源性激光雕刻橡塑印章因其规格性特征符合很好,检验鉴定要以细节特征比对为主。     

丝网版印章印文特征辨析

介绍了丝网版印章的制作工艺,分析了丝网版印章印文特征的可变性和稳定性,总结了丝网版印章印文检验的方法,为司法鉴定实践中此类印章印文的真伪鉴别工作提供一定参考。     

试论光敏印章盖印印文的检验

目的　探讨光敏印章盖印印文形成机理 ,总结检验方法。　方法　查勘刻制光敏印章流程 ,制作光敏印章 ,观察其盖印印文特点 ,查阅相关资料 ,结合检案实践对印文特征进行评析。　结果　弄清了光敏印章的制章原理 ,提出了光敏印章种类鉴别和个体鉴别的特点和方法。     

原子印章及其特征

本文初步探讨了原子印章的构成、生产工序特点及其印文特征,可供检验原子印章时参考。     

印章印文盖印时间鉴定的实践研究

通过对近年来我们受理的印章印文盖印时间鉴定实际案例进行系统的研究,较全面地阐述了印章印文阶段性特征中常见定性特征和定量特征及其在鉴定实践中的运用．并重点讨论了印文阶段性特征中定量特征在鉴定实践中的运用,初步探讨了进一步利用这些定量特征建立统计学模型的可能性。     

印文大小特征变化在印文盖印时间鉴定中的应用

印章盖印时间是判断文件形成时间,进而判断文件真伪的一个重要要素。通过对印章胀缩导致的印文大小特征变化的分析,探讨了印文大小特征变化在印文盖印时间鉴定中的应用,讨论了利用印文大小特征变化进行印文盖印时间鉴定的方法和注意事项,并介绍了两起实际案例。     

A study on the use of photopolymer reflex plate in the forgery of Chinese seals

This study compares the identifying characteristics between the impressions made with original Chinese seals and photopolymer replicate seals, and between the impressions made with two photopolymer replicate seals that originate from one single negative. Various seal materials common to the Chinese community such as cow's horns and ivory are employed. Other than the common factors such as different incident angle upon imprinting or different degree of inking that constitute the natural variation in impressions, the physical changes of the seal materials with temperature will be considered. This study concludes that photopolymer replicate seal impressions can be differentiated from the originals in respect to print density and stroke morphology, but it is very difficult to differentiate between two photopolymer replicate seal impressions with the same origin. This study also proposes a simple method for the examination of forged Chinese seal impressions.     

Forged seal detection based on the seal overlay metric

This paper describes a method for verifying the authenticity of a seal impression imprinted on a document based on the seal overlay metric, which refers to the ratio of an effective seal impression pattern and the noise in the neighborhood of the reference impression region. A reference seal pattern is obtained by taking the average of a number of high-quality impressions of a genuine seal. A target seal impression to be examined, often on paper with some background texts and lines, is segmented out from the background by an adaptive threshold applied to the histogram of color components. The segmented target seal impression is then spatially aligned with the reference by maximizing the count of matching pixels. Then the seal overlay metric is computed for the reference and the target. If the overlay metric of a target seal is below a predetermined limit for the similarity to the genuine, then the target is classified as a forged seal. To further reduce the misclassification rate, the seal overlay metric is adjusted by the filling rate, which reflects the quality of inked pattern of the target seal. Experiment results demonstrate that the proposed method can detect elaborate seal impressions created by advanced forgery techniques such as lithography and computer-aided manufacturing.     

光谱成像检验法在朱墨时序鉴定中的应用

光敏印文色料与签字笔书写色料交叉重叠后,因互溶渗透不易形成层状结构而使判定朱墨时序的难度较大。光谱成像检验法是通过比较交叉点、纯印文色料、纯墨迹色料处的反射曲线位置来判定交叉时序关系。     

印文鉴定相关问题探讨——高仿真印文鉴定

当前,与印文鉴定相关的并在鉴定实践中经常遇到的新问题和难点问题有高仿真印文的鉴定、变造印章问题、利用真实印文变造文件、同版印章印文、朱墨时序等,本文就高仿真印文的鉴定进行了系统阐述,介绍了各种高仿真印文,包括各种高仿真印章的盖印印文、复制印文、转印印文的伪造手段及其特点,并提出了高仿真印文的鉴定思路和要点。     

对鞋内底足迹的研究与应用

刑事案件中对足迹的发现、提取、利用是很寻常的事,人们已习惯了运用各种检验技术对鞋外底遗留足迹特征检验、运用。而本文则是作者在总结实际办案的经验和教学研究的基础上,以鞋内底足迹为切入口,重点谈谈鞋内底足迹的概念、形成机理、特征及应用。     

Unusual facial markings and lethal mechanisms in a series of gasoline inhalation deaths

A review of deaths associated with hydrocarbon toxicity from gasoline sniffing in South Australia throughout a 10 year period from July 1987 to June 2002 revealed 4 cases. The victims were all Aboriginal people from remote inland communities. Each death had occurred while the victim was lying in bed sniffing gasoline from a can held to the face. Once unconsciousness had occurred, the mouth and nose had been pressed firmly against the can by the weight of the head. In each case, the effects of gasoline toxicity had been exacerbated by hypoxia and hypercapnia from rebreathing into the container once a tight seal had been established between the face and the can. The circular impressions left by the can edges on the faces of each of the victims provided an autopsy marker that assisted in clarifying the details of the fatal episodes. Discouraging solitary gasoline sniffing in bed may reduce the death rate in communities where this behavior is practiced.     

Chemical enhancement of footwear impressions in blood on fabric — Part 3: Amino acid staining

Enhancement of footwear impressions, using ninhydrin or ninhydrin analogues is not considered common practice and such techniques are generally used to target amino acids present in fingermarks where the reaction gives rise to colour and possibly fluorescence. Ninhydrin and two of its analogues were used for the enhancement of footwear impressions in blood on various types, colours and porosities of fabric. Test footwear impressions on fabric were prepared using a specifically built rig to minimise the variability between each impression. Ninhydrin enhancement of footwear impressions in blood on light coloured fabric yielded good enhancement results, however the contrast was weak or non-existent on dark coloured fabrics. Other ninhydrin analogues which have the advantage of fluorescence failed to enhance the impressions in blood on all fabrics. The sequential treatment of impressions in blood on fabric with other blood enhancing reagents (e.g. protein stains and heme reagents) was also investigated.     

Lifting Bloody Footwear Impressions Using Alginate Casts Followed by Chemical Enhancement

A method for lifting bloody footwear impressions using alginate casts and enhancing the lifted impressions with amido black is presented. On rough or dark substrates, background interferences may conceal significant details of footwear impressions. Illumination with alternative light sources and chemically enhancing the bloody footwear impressions may reveal additional details, but sometimes, lifting footwear impressions prior to enhancing is the only way to expose hidden details (by using blood reagents not adequate on the original). Several cast formulations were tested for lifting the footwear impressions. The best results were achieved using Aroma fine^®. Enhancement of the footwear impressions was attempted with several reagents prior to lifting, during the casting process, and on the lifted footwear impressions. Applying amido black to footwear impressions lifted with alginate produced the sharpest and most detailed footwear impressions. Alginate castings followed by chemical enhancement with amido black may produce high‐quality footwear impressions for comparison.     

自含墨印章印文盖印时间受老化条件的影响

目的探索利用气相色谱法较精确、定量测定自含墨印章印文盖印时间受人为老化条件的影响。方法分别在恒温烘烤、紫外线照射、纯水浸泡等人为老化条件下,测定自含墨印章印油中所含有的主要相关溶剂成份的含量变化。结果得出了主要溶剂成份在人为老化条件下其含量的变化规律以及人为老化与自然老化的对应关系。结论利用气相色谱法可以对不同保存条件下自含墨印章印文的盖印时间进行测定,为实际相关案件的检验提供了依据。