裂解气相色谱-质谱法分析鉴别轮胎胎面胶

目的对裂解气相色谱-质谱法分析橡胶的裂解条件进行优化,研究利用橡胶特征裂解产物鉴别轮胎胎面胶。方法采用裂解气相色谱-质谱法,确定对NR、BR、SBR的裂解条件及其特征裂解产物,然后根据特征裂解产物及其相对含量并结合聚类分析,对38种轮胎胎面胶进行区分鉴别。结果确定了裂解温度590℃、裂解时间15s及三种橡胶的特征裂解产物;将38个轮胎胎面胶样品的主体成分归为4类,其中NR类5个、SBR类12个、NR/BR并用类5个、NR/SBR并用类16个,且能够对大部分并用类轮胎胎面胶进行鉴别。结论通过优化裂解条件,裂解产物重复性好,特征裂解产物明显,能够确定轮胎胎面胶的主体成分类别并能对大多数并用类轮胎胎面胶样品进行区分鉴别。     

高效液相色谱法鉴别染料型黑色喷墨打印字迹

目的建立液相色谱分析方法,对市售的30种不同厂家牌号（原装）染料型黑色喷墨打印字迹进行区分鉴别。方法通过选择最佳的提取条件、流动相,考察纸张、字迹形成方式等的影响,及样品及仪器的稳定性实验,确定实验条件。结果选择了最佳的反相高效液相色谱（RP-HPLC）分析方法：固定相为X-bridge Shield RP18（3.5μm,4.6×100mm）,流动相为乙腈-NH4HCO3溶液（10mmol/L）,梯度洗脱,检测波长为585nm、475nm;用该方法,根据字迹染料成分的差异将30种样品分为四大类17小类。结论该方法可以为鉴别区分不同厂家染料型黑色喷墨打印字迹提供依据。     

利用轮胎花纹个性特征点认定交通肇事逃逸车辆

在利用轮胎花纹痕迹认定交通肇事车辆的工作中，通常是利用花纹类型（横沟花纹、纵沟花纹、块状花纹、混合花纹、非对称花纹）及适用的车辆种类等共性特征进行分析鉴定。由于轮胎是机械化流水作业生产，同一品牌、同一型号的轮胎，其花纹是相同的，而同种轮胎又可以安装在不同品牌的车辆上。因此利用共性特征仅能区分肇事车辆的种类，不能认定某一辆嫌疑车就是肇事逃逸车辆。笔者根据实战经验，根据轮胎花纹个性特征点来认定肇事逃逸车辆，本文就此展开如下讨论。     

利用热重法鉴别汽车轮胎橡胶

目的建立热重法对汽车轮胎橡胶进行鉴定的方法。方法应用热重法对12种轮胎橡胶样品进行分析。结果分别获得了12种轮胎橡胶的TG及DTG曲线和它们在三个阶段的失重百分率、DTG的峰温。结论可以方便地鉴别组成不同或牌号不同的轮胎橡胶制品,为划定与缩小嫌疑车辆的范围和认定肇事车辆提供依据。     

关于车辆碾压人体的鉴定

目的 判断车辆是否碾压过人体.方法 应用痕迹检验的方法对车体及轮胎的痕迹进行检验,并结合人体损伤特征进行分析.结果 车辆碾压人体鉴定的具体方法.结论 车辆碾压人体鉴定可以通过车体痕迹、轮胎花纹与人体及衣物上的印痕比对、人体损伤特征等方面进行判断.     

SEM/EDS法和XRF法在电工胶带检验中的应用

目的探索电工胶带带基的元素检验方法。方法利用扫描电镜/能谱法（SEM/EDS）对电工胶带带基中的主体元素进行定量分析,通过SPSS软件对SEM/EDS定量分析法检测出的主体元素（Cl和Ca）相对含量进行统计分析;利用X射线荧光光谱法（XRF）对电工胶带带基中的微量元素进行定性分析。结果34个品牌红色电工胶带组成的561组样品对通过SEM/EDS定量分析法可以区分539组,区分率达到96.1%;根据XRF法定性分析测出的Mg、Al、Si、S、Ti、Sb、Ba、Pb微量元素的不同组合可将34种电工胶带分成11组,两种方法结合可使不同品牌红色电工胶带的区分率达到98.4%。结论SEM/EDS法和XRF法结合可以实现同种颜色、不同品牌电工胶带的高效区分。     

采血管中添加剂对血样中乙醇含量的影响

目的：探讨不同种类采血管对血样中乙醇含量检测结果的影响。方法分别用7种一次性真空采血管[无抗凝剂管、促凝剂管、分离胶-促凝剂管、枸橼酸钠（1∶4）管、枸橼酸钠（1∶9）管、柠檬酸钠（9∶1）管、EDTA-K2管]采集10名志愿者饮酒后2 h血液,用顶空气相色谱法检测血样中乙醇含量。结果相同血样用不同的采血管,其乙醇含量检测结果不同,依次为分离胶-促凝剂管〉促凝剂管〉无抗凝剂管〉EDTA-K2管〉枸橼酸钠（1∶9）管〉枸橼酸钠（1∶4）管,柠檬酸钠（9∶1）管与枸橼酸钠（1∶9）管检测结果基本一致。结论采集涉嫌酒后驾驶的驾驶员血样,应选用一次性真空采血管,首选EDTA-K2管。     

交通事故轮胎鉴定概述

轮胎鉴定是指涉及事故车辆的轮胎相关的鉴定项目,是交通事故技术鉴定中的重要项目之一,一般可分为轮胎痕迹鉴定和轮胎损坏情况及其与事故关系鉴定两种.本文着重论述了交通事故技术鉴定中上述两种轮胎鉴定的定义、鉴定步骤、鉴定方法,并通过典型案例来全面解读轮胎鉴定的具体鉴定过程.     

微波消解ICP-MS法测定人头发中24种元素的含量

目的建立人头发中24种无机元素的电感耦合等离子体质谱（inductively coupled plasma-mass spec-trometry,ICP-MS）分析方法。方法采用微波消解法处理样品,以铟（115In）作内标,用ICP-MS分析人头发中的24种元素含量。同时检测56例健康志愿者和10例海洛因滥用者头发中24种元素含量。结果 24种元素的方法检出限范围为0.0003~10.14μg/g,标准物质的测得值与标准值基本相符。海洛因滥用者经戒毒治疗后头发中镁、镓、钡含量下降。结论该方法灵敏度、准确度高,适用于头发中24种元素的测定。     

集同轴线、双绞线、网线、电力线传输于一体——三锐SE-CP9206ER智能蜘蛛侠系列红外高清IPC新品出炉

三锐SE-CP9206ER智能蜘蛛侠系列网络摄像机,是基于第一代电力线网络高清摄像机传输、第二代电力线网络高清摄像机传输、施工现场使用及公司研发工程师不断努力摸索推进改善,研发出的第三代PLC有线通多功能网络高清摄像机,其具备四种传输方式：1.同轴网络高清视频线传输 （2KM）;2.双绞线网络高清传输（1.2KM）;3.网线网络高清传输（100M）;4.电源线电力载波网络高清传输（300M）.配合三锐推出的高清万能接线盒,使得每台网络摄像机在一根同轴线或双绞线上面可以实现多台网络高清摄像机任意组网联网传输,节省了施工、安装、线材成本.此外,高清万能接线盒可以兼容市场上面的不同品牌的网络摄像机进行不同传输方式的组网.     

The analysis of tire rubber traces collected after braking incidents using Pyrolysis-GasChromatography/Mass Spectrometry

Automobile tire marks can routinely be found at the scenes of crime, particularly hit-and-run accidents and are left on road surfaces because of sudden braking or the wheels spinning. The tire marks are left due to the friction between the tire rubber and the solid road surface, and do not always demonstrate the tire tread pattern. However, the tire mark will contain traces of the tire. In this study, Pyrolysis Gas Chromatography/Mass Spectrometry was used to analyze 12 tires from different manufacturer's and their traces collected after braking incidents. Tire marks were left on a conglomerate road surface with sudden braking. The samples were pyrolysed without removal of contaminant in a micro-furnace type pyrolyser. Quantitative and qualitative analysis were performed on all the samples. All 12 samples were distinguished from each other. Each of the tire traces were identified as coming from there original source.     

Matching tire tracks on the head using forensic photogrammetry

In the field of the documentation of forensics-relevant injuries, from the reconstructive point of view, the forensic, CAD-supported photogrammetry plays an important role; particularly so when a detailed 3-D reconstruction is vital. This is demonstrated with a soft-tissue injury to the face caused by being run over by a car tire. Since the objects (injury and surface of the tire) to be investigated will be evaluated in virtual space, they must be series photographed. These photo sequences are then evaluated with the RolleiMetric multi-image evaluation system. This system measures and calculates the spatial location of points shown in the photo sequences, and creates 3-D data models of the objects.In a 3-D CAD program, the model of the injury is then compared against the model of the possible injury-causing instrument.The validation of the forensic, CAD-supported photogrammetry, as shown by the perfect 3-D match between the tire tread and the facial injury, demonstrates how greatly this 3-D method surpasses the classic 2-D overlay method (one-to-one photography).     

A bizarre case of vehicular suicide

The upper torso of a man was discovered under a highway sign next to tire tread marks leading from the highway and continuing beyond the sign. The victim's lower torso and automobile were also found along the same path 31 m (101 ft) and 41 m (133 ft) beyond the sign, respectively. The decedent was initially thought to be a disposed, homicide victim who had been dismembered by his assailant(s). Accident reconstruction revealed that the victim was the driver of the automobile and was transected by the highway sign stanchion as he protruded through the passenger side window of his moving vehicle. Based on the scene findings, autopsy, and psychological autopsy, the manner of death was classified as suicidal. The criteria used by medical examiners for vehicular suicide are also discussed.     

利用“WA”花纹的车胎印痕推定轮胎规格

对于“WA”花纹的车胎印痕,根据其花纹的结构可以进一步推定轮胎的规格,这对于确定犯罪嫌疑车辆有着非常重要的意义.本文从胎面“WA”花纹的排布规律入手,结合外界条件的变化对花纹的影响,阐述了这种推定的可行性.     

A method for the determination of syringe needle punctures in rubber stoppers using stereoscopic light microscopy

The ability to accurately determine the number of syringe needle penetration holes through the rubber stoppers in pharmaceutical vials and rubber septa in intravenous (i.v.) line and bag ports has been a critical factor in a number of forensic cases involving the thefts of controlled substances or suspected homicide by lethal injection. In the early 1990s, the microscopy and microanalysis group of the U.S. Food and Drug Administration's Forensic Chemistry Center (FCC) developed and implemented a method (unpublished) to locate needle punctures in rubber pharmaceutical vial stoppers. In 1996, as part of a multiple homicide investigation, the Indiana State Police Laboratory (ISPL) contacted the FCC for information on a method to identify and count syringe needle punctures through rubber stoppers in pharmaceutical vials. In a joint project and investigation using the FCC's needle hole location method and applying a method of puncture site mapping developed by the ISPL, a systematic method was developed to locate, identify, count, and map syringe punctures in rubber bottle stoppers or i.v. bag ports using microscopic analysis. The method requires documentation of punctures on both sides of the rubber stoppers and microscopic analysis of each suspect puncture site. The final result of an analysis using the method is a detailed diagram of puncture holes on both sides of a questioned stopper and a record of the minimum number of puncture holes through a stopper.     

The application of TreadMatch scans to aid the process of footwear mark comparison

Currently in the UK, if a person is arrested or charged with a recordable offence, they can have prints of their footwear taken whilst in custody. The tread pattern recorded in these prints can be searched for using the National Footwear Database to find out if the same footwear pattern has been recovered at previous crime scenes, generating forensic intelligence.TreadMatch is a digitised system for collecting footwear prints seized from detainees in custody for this purpose. Whilst its use for generating intelligence is accepted, validation experiments have not been conducted to understand its level of performance in assisting in forensic comparison purposes for identification, because in the absence of an incorporated scale, it is not known how well TreadMatch reproduces the pattern size of a tread, threatening the validity of the comparison. If it can be determined that the measurements of TreadMatch scans are consistent with the more commonly used aluminium powder test marks, this could save Police time and resources if the digital scans could be used for preliminary assessment prior to the footwear being physically submitted for evidential comparison. Therefore, this study set out to compare three different types of TreadMatch scans (‘dynamic’, ‘zoomed’ and ‘rolled’) for thirty different pieces of footwear, with test marks of the same footwear using the traditional method (fingerprint powder). Length and width measurements were obtained from each tread pattern using GNU Image Manipulation Program software. The resulting data were analysed to assess for agreement between TreadMatch scans and test marks using 95% Intraclass Correlation Coefficients (ICC) and 95% Bland-Altman plots of Limits of Agreement (LOA). Additionally, an intra-sample study using fifteen repeated measurements of the same piece of footwear for different TreadMatch scanning methods was carried out to support the larger validity study.95% ICC_3,1 resulted in coefficients ranging from 0.99 to 1.00 across all measurements. 95% LOA displayed close agreement. There was less agreement and more variation displayed between the test marks and the TreadMatch rolled scans for both length and width measurements. This variation for hand-rolled prints must be taken into consideration and a standard approach developed. The study suggests TreadMatch can be used for preliminary assessments in assisting forensic comparisons, particularly for dynamic and zoomed prints.     

交通事故中轮胎爆破痕迹的检验与应用

车辆轮胎爆破在交通事故中较为常见,对爆胎痕迹进行检验和鉴定,弄清爆胎原因,在查明事故真相和责任认定中起着至关重要的作用。由于爆胎痕迹形成机理和原因复杂,检验鉴定的难度较大。通过对各类爆胎痕迹的形态特征及其差异的讨论,提出了交通事故中爆胎痕迹的检验要点。