火灾发生起数的区间估计和假设检验

在分析火灾发生概率规律性的基础上,可在一定的置信水平上,对火灾发生的起数进行区间估计和假设检验。通过区间估计将未来的火灾形势预测为一个置信区间,通过假设检验可排除随机干扰,确定火灾发生起数的变化规律,这些信息都能为消防规划的制定提供科学的数量依据。     

微量物证理化检验实验室认可工作的特点

文章结合我国微量物证检验工作的现状,对微量物证实验室认可工作的特点、难点以及认可中容易出现的问题进行了分析,在此基础上提出了具体的注意事项和建议。     

论犯罪心理测试前的访谈

测试前访谈技术是心理测试技术的重要组成部分。犯罪心理测试前访谈是为了让受测者从心理上对即将开始的测试做好准备。如果不进行访谈,或者访谈进行得不好,就很难达到测试的目的。     

Gc亚型检测的复合MS-PCR法及其应用

目的探讨建立Gc亚型检测的复合MS-PCR法及其应用价值。方法根据Gc基因中的2处点突变,设计2对片段相差5bp的等位基因特异性引物和1条公共引物进行复合MS-PCR,分析Gc多态性,并调查武汉地区218例汉族无关个体Gc多态性和鉴定10例亲子关系。结果复合MS-PCR检测的Gc基因型,与AmpliTypePM试剂盒的分型结果一致;武汉地区汉族人群Gc基因的3个常见等位基因Gc1F、Gc1S、Gc2的基因频率分别为0.4816、0.2592、0.2592,观察杂合度(Hobs)、期望杂合度(Hexp)、多态性信息含量(PIC)、个人识别能力(DP)、非父排除率(PE)分别为0.6193、0.6359、0.6253、0.7974、0.3480,基因型分布符合Hardy-Weinberg平衡;真三联体和非真三联体亲子鉴定各5例,前者不排除父子关系,与常规STR分型一致,后者经Gc-MS-PCR分型排除2例。结论建立复合MS-PCR法检测Gc亚型在法医物证鉴定中有实用价值。     

谈文件检验在侦破匿名信敲诈案件中的应用

近年来,全国各地匿名信敲诈案件大量发生。作案人使用伪造的或非本人的身份证到银行申领信用卡,书写或打印匿名信件对知名人士或各类企业、各级党政机关人员进行敲诈,严重扰乱和影响了社会正常生活秩序,甚至严重危害社会公共安全。文件检验是侦破此类案件的重要手段和突破口。     

犯罪心理测试程序规范化研究--刑事诉讼的角度

犯罪心理测试作为科技发展的一项成果,在许多国家刑事诉讼中已经得到运用,也显示了其作用.我国自引进这项技术以来在司法实践中产生了一定的效果,但在理论上仍存在着较大争议.我国目前并无对犯罪心理测试的明确法律规范,也就使得其实施虽然是在刑事诉讼过程中进行的,但同时又缺乏相应的程序规范.这是与程序法治所格格不入的,必须从诉讼法的角度对其应用程序进行规范.     

Empirical Evaluation of the Reliability of Photogrammetry Software in the Recovery of Three-Dimensional Footwear Impressions

This paper examines the reliability of Structure from Motion (SfM) photogrammetry as a tool in the capture of forensic footwear marks. This is applicable to photogrammetry freeware DigTrace but is equally relevant to other SfM solutions. SfM simply requires a digital camera, a scale bar, and a selection of oblique photographs of the trace in question taken at the scene. The output is a digital three-dimensional point cloud of the surface and any plastic trace thereon. The first section of this paper examines the reliability of photogrammetry to capture the same data when repeatedly used on one impression, while the second part assesses the impact of varying cameras. Using cloud to cloud comparisons that measure the distance between two-point clouds, we assess the variability between models. The results highlight how little variability is evident and therefore speak to the accuracy and consistency of such techniques in the capture of three-dimensional traces. Using this method, 3D footwear impressions can, in many substrates, be collected with a repeatability of 97% with any variation between models less than ~0.5 mm.     

Nondestructive Differentiation of Polyester Single White Fibers Using Synchrotron Radiation Microbeam X-ray Fluorescence Spectrometry with Vertical Focusing

In this study, the nondestructive differentiation of individual white polyester clothing fibers was accomplished via synchrotron radiation microbeam X-ray fluorescence (SR-μ-XRF) analysis. SR-μ-XRF with vertical focusing is a useful nondestructive method for the analysis of a single polyester clothing fiber. Kirkpatrick–Baez (KB) mirror was used to vertically focus 20 keV X-rays for the analysis of 22 individual white polyester fibers taken from clothing commonly sold in Japan. SR-μ-XRF with a vertical focused 2 μm (V) × 300 μm (H) beam was approximately 12.8 times more sensitive than SR-XRF with an unfocused 300 μm (V) × 300 μm (H) beam for the detection of elements in single fibers. The minimum detection limits (MDLs) of the SR-μ-XRF method were 8.15 ppm for Cl and 0.06 ppm for Br. In addition to Ti in TiO₂ delustering agents, Zr and Nb impurities in the delustering agents were detected in individual fibers. Sb from a polymerization catalyst and Co from a transesterification catalyst were also detected in individual fibers. Comparing the Ti K_β/Sb L_α,β and Zr K_α/Nb K_α X-ray intensity ratios was a useful way to distinguish individual clothing fibers, and 98% of the fibers were differentiated when additional trace elements were used as discrimination indicators.     

The Error in “Error Rate”: Why Error Rates Are So Needed,Yet So Elusive

Establishing error rates is crucial for knowing how well one is performing, determining whether improvement is needed, measuring whether interventions are effective, as well as for providing transparency. However, the flurry of activities in establishing error rates for the forensic sciences has largely overlooked some fundamental issues that make error rates a problematic construct and limit the ability to obtain a meaningful error rate. These include knowing the ground truth, establishing appropriate databases, determining what counts as an error, characterizing what is an acceptable error rate, ecological validity, and transparency within the adversarial legal system. Without addressing these practical and theoretical challenges, the very notion of a meaningful error rate is limited.     

Evaluation of Suspected Counterfeit Pharmaceutical Tablets Declared to Contain Controlled Substances Using Handheld Raman Spectrometers

This study describes the performance of handheld Raman devices for determining whether suspect pharmaceutical tablets declared to contain controlled substances were consistent with authentic (CWA) or not consistent with authentic (NCWA) tablets using a simple, rapid, field-friendly method capable of being used by nonexperts. Twenty-five authentic products and 84 known NCWA tablets were examined using three “parent” devices for a total of 327 analyses. On average, the parent devices yielded a true pass rate of 100%, a true fail rate of 98.4%, a false pass rate of 1.6%, and a false fail rate of 0%. The methods/libraries were then transferred to 13 identical “daughter” devices, which were used to examine 10 suspect finished dosage forms in duplicate (six known NCWA tablets and four authentic tablets) for a total of 260 measurements. On average, the daughter devices had a true pass rate of 100%, a true fail rate of 95.5%, a false pass rate of 4.5%, and a false fail rate of 0.0%. These data demonstrate that the parent–daughter electronic transfer method was successful, which permits the ability to develop methods in the laboratory that can be seamlessly pushed out to field devices. The methods can then be used to (i) prioritize samples for additional testing using other more time-consuming laboratory-based techniques needed to detect and quantify active ingredients and (ii) help support the interdiction of dangerous tablets at ports of entry, thereby preventing them from reaching the supply chain.