运用“502”粘合剂显现长时间潜在手印的研究及应用

本文对“502”粘合剂显现手印法进行适当的技术改进,通过显现一起潜在手印遗留时间长达一年以上罕见案例的实际应用,并对操作方法和影响因素等方面进行讨论,以拓宽“502”粘合剂显现潜在手印的应用范围.     

A Latent Variable Analysis of General Strain Theory

Strain theory has returned to the forefront of criminological theory and research, due primarily to the general strain model developed by Robert Agnew. Agnew posits that a broad range of negative social relations comprises strain and that these straining mechanisms lead to delinquent behavior and other maladaptive functioning. Moreover, strain has its strongest effect on delinquency when certain coping strategies are attenuated or when delinquent peers reinforce perceptions of strain. Although several studies have now shown the utility of general strain theory as an explanation of delinquency, they have relied mainly on cross-sectional effects or two-wave panel designs using methods that fail to consider measurement error or autocorrelated errors. In this study we extend these analyses by estimating a latent variable structural equation model that examines the effects of strain—operationalized as negative life events—on conventional attachment and delinquency over a 3-year period. Furthermore, we directly assess Agnew's coping strategies hypotheses by stratifying the models by self-efficacy, self-esteem, and peer delinquency. The results indicate that significant longitudinal effects of strain on delinquency emerge during year 3 but that these effects are not conditioned by self-efficacy or self-esteem. Changes in strain also affect changes in delinquency, but only among those who report no delinquent peers. We do find, however, that over the initial 2 years strain has a negative effect on delinquency among those high in self-efficacy, self-esteem, or delinquent peers. The findings are discussed in terms of Agnew's theory.     

浅谈全自动指纹识别系统管理及运用

“指纹自动识别系统”作为一种高科技手段 ,已经在刑侦领域得到了广泛的应用。在应用的过程中 ,一定要注意指纹采集、贮存、检索一体化 ,同时还要抓该项工作管理制度的落实与操作人员素质的提高 ;尤其是在检索时 ,更要注意指纹与案件的必然联系     

用非放射性标记MYO探针进行DNA指纹分析

用非放射性标记ＭＹＯ探针进行人的ＤＮＡ指纹分析，获得了清晰易读的ＤＮＡ指纹图，并用该方法调查了云南省的７８名无关个体，经统计学分析，计算出无关个体的相关几率是３．４×１０－１０，高于３２Ｐ标记的Ｍｙｏ探针。研究结果表明该方法是一种简便、快速、灵敏、可靠、经济的ＤＮＡ指纹图检测技术，可在法医鉴定及其它领域里得到更广泛的应用。     

利用碘胶纸贴附法显现汗潜手印

碘熏显手印法，是现场勘查中显现汗潜手印的方法之一。由于传统的和现有的方法有时受到现场空间的制约，无法兼顾水平面、垂直面、凸凹面以及狭窄处的手印显现。为此，笔者研制了一种安全、快捷、简易、经济、适用于基层使用的操作装置和方法。     

对暗视场显现指印汗孔细节特征的初步研究

在指印鉴定工作中,利用汗孔细节特征对指印进行同一认定在国外司法鉴定领域已有应用,但在实际案件中,由于汗孔细节特征的发现和提取较为困难,同时对汗孔的分类、命名、标示等又存在一些没有解决的问题,目前在我国刑事技术领域还没有得到应用。文章采用一种常用的配光方法———暗视场照明方法,显现光滑平面玻璃上汗潜指印的汗孔细节特征,并对实验中影响汗孔细节特征形成的部分因素进行了初步研究。     

Detection of pretreated fingerprint fluorescence using an LED-based excitation system

Abstract:  Optimization of a light emitting diode (LED)-based excitation system for the detection of pretreated fingerprint fluorescence is described. Fluorescent ridges can usually be excited by irradiation with forensic light sources such as xenon arc lamps or quartz-halogen lamps with high-power output and suitable filters. However, they are too expensive for many crime laboratories in smaller organizations. We concentrated on LEDs which have advantages over conventional light sources in that they are simpler and of lower cost, but the power output and quality of each individual LED unit is not sufficient for the detection of weak fluorescent ridges. To resolve this subject, blue and green LED arrays composed of ninety LED units were adopted and suitable low pass filters for them were designed. An experimental system, consisting of blue and green LED arrays with the suitable low pass filters for illumination, high pass filters for viewing, a digital camera and a computer, was tested. The fluorescent images of cyanoacrylate ester fumed/rhodamine 6G stained fingerprint on white polyethylene sheet and weak fluorescent ridges of ninhydrin/indium chloride treated fingerprint on white paper were successfully detected and photographed. It was shown that the improvement of LED beam in intensity and quality can compensate the disadvantages, resulting in well-contrasted images.     

基于数据仓库与数据挖掘的自动指纹识别系统的探讨

通过对已有自动指纹识别系统的分析、研究 ,针对目前的自动指纹识别系统存在的建库速度慢 ,采集速度慢 ,错、漏率高 ,匹配效率差等缺陷 ,探讨了基于数据仓库和数据挖掘的自动指纹识别系统。     

油红O显现手印配方中各物质的作用验证

目的研究油红O显现手印配方中各物质的作用及其对显现效果的影响。方法对配方中的主要成分进行定性、定量实验来分析、考察实验结果。结果油红O粉末的颜色与显出的手印纹线颜色关系较大,溶液中的氢氧化钠关系着显出的手印纹线与背景的反差。结论 Alexandre Beaudoin公布的配方稳定、显现效果好,值得在实践工作中推广。     

An Investigation into the Effects of Force Applied During Deposition on Latent Fingermarks and Inked Fingerprints Using a Variable Force Fingerprint Sampler

Physical factors, including the magnitude of the force applied during fingermark deposition, may affect friction ridge surface area and clarity, and the quantity of residue transferred. Consistency between fingermarks may be required; for example, in research projects, yet differences between marks are likely to exist when physical factors are not controlled. Inked fingerprints and latent fingermarks were deposited at 1–10 N at 1 N increments using a variable force fingerprint sampler to control the force, angle of friction ridge and surface contact, and the duration of friction ridge and surface contact. Statistically significant differences existed between the length and width measurements of the inked prints (p ≤ 0.05), particularly at lower forces. Scanning electron microscopy and surface plot analysis demonstrated how differences in force applied during deposition affected ridge surface area, displacement of latent residue, and differences in the quantity of residue transferred. Consistency between inked prints was demonstrated at equivalent forces.