机车闸瓦熔渣导致的护坡起火现场勘查分析

青藏铁路是进出藏运输大动脉,客运和货运量巨大,具有极高的战略地位,铁路护坡起火严重危害青藏铁路行车安全。本文通过对青藏铁路格拉段沿线发生的5例起火事件的现场勘查,排除了人为因素导致起火的可能性。结合事发地地理环境以及列车闸瓦特性,明确发生的火灾事件均由机车闸瓦熔渣飞溅点燃护坡杂草导致。本文为此类事件的调查取证和事件定性提供了参考,并为防范青藏铁路类似事件的发生提出了预防措施。     

An Empirical Study on the Relation Between the Critical Angle for Bullet Ricochet and the Properties of Wood

The properties of a bullet, an object, and the incidence angle determine whether the bullet will penetrate, perforate, or ricochet. In this study, the critical angle for ricochet was established for .32 Auto and 9 mm Luger bullets on Abachi, Southern Yellow Pine, Beech, and Ipe wooden boards. Results show that the critical angle differs depending on caliber and wood type. The critical angle is higher for .32 Auto bullets than for 9 mm Luger bullets and increases with increasing wood density and Janka hardness. The established critical angles for ricochet on the lightest and softest wood (Abachi) are 10.4° and 10.3° for .32 Auto and 9 mm Luger, respectively. For the heaviest and hardest wood (Ipe), the angles were 45.0° and 33.4°, respectively. The combined results on the four tested woods show a strong linear relationship between both the density and the hardness and the critical angle for both calibers.     

Investigating the Potential of Fluorescent Fingerprint Powders as a Marker for Blow Fly Larvae (Diptera: Calliphoridae)

Four fluorescent fingerprint powders (RedWop^?, GreenWop^?, Basic Yellow^?, and Yellow Powder^?) were evaluated as a marker for blow fly larvae. Administration methods included ingestion (high vs. low concentration) or topical. Ingestion of high concentrations of Basic Yellow^? and RedWop^? caused higher larval mortality. Basic Yellow^? delayed development and adult emergence while RedWop^? and Yellow Powder^? had a significant effect on particular stages of development, however, emergence time was not altered. Optimal administration is through ingestion at low concentration levels (<10%) or topically, with GreenWop^? demonstrating minimal adverse effects. Optimum wavelength for discrimination between powders was 450 nm. This research can aid in investigative training to increase visibility of larval and pupal blow flies. It can also be used in entomological studies to differentiate between larval blow flies (or other dipteran) species or individuals to further understand complex interactions and behavior during larval development.     

浅析犯罪现场中的物质痕迹和心理痕迹

犯罪现场存在着物质痕迹和心理痕迹。物质痕迹具有广泛性、稳定性特点 ;心理痕迹具有客观性、可知性、抽象性、间接性、隐蔽性等特点。物质痕迹和心理痕迹既相互联系、又相互区别。对犯罪现场的物质痕迹和心理痕迹作理论性和应用性研究 ,旨在探索一条新的侦查途径和思路 ,开拓侦查思路 ,为刑事破案服务     

对一起离奇交通事故的物证技术分析

文章综合运用物证技术手段对一起看似离奇的交通事故进行了全面分析和重现,并详细介绍了交通事故现场微量物证的发现、提取和检验方法。     

抛尸现场相关物品的辨析

抛尸现场的相关物品是指在抛尸现场与尸体有直接联系的有关物品。刑技人员在做好现场勘验和尸体检验的同时要认真发现、提取、检验与尸体有直接联系的有关物品,分析研究有关物品的内在联系信息,为案件的侦破提供方向,为诉讼提供证据。     

147例凶杀案的法医学分析

通过对上海地区中147例凶杀案尸检的分析,从案件情况、现场勘察及尸体检验等方面进行归纳,总结了此类案件的共同特点,以期为凶杀命案的检验、侦破提供参考。     

"大话"文化:"电子场景"下青年文化的"中区倾向"

"大话"文化是"电子场景"下成长起来的青年人在行为方式上的主动变革,从而形成的一种"中区倾向"的行为模式,"大话"文化只能以青年文化的面目出现.对于"大话"文化现象,不能轻易地以价值判断对其进行盖棺定论,它实际上是人们在"电子场景"下行为模式转变的一个信号而已.     

浅谈视频监控技术在现场勘查中的作用

视频监控技术是公安机关打击和防控违法犯罪常用的一种技术手段,在刑事现场勘查中也有着举足轻重的作用。正确运用视频监控技术,可以明确现场勘查取证重点,可以有效采取现场紧急措施,可以快速甄别现场痕迹物证,可以提高侦查实验结果的可靠性。     

An investigation into the differentiating characteristics between car key burglars and regular burglars

Car key burglary has recently become the focus of empirical investigation as offenders, no longer able to steal vehicles without first obtaining their keys, resort to "burgling" target properties. Research surrounding the modus operandi of these offenses is beginning to emerge; however, little attention has been paid to investigating the characteristics of car key burglary offenders. Challenging the assumption that car key burglary offenses are perpetrated by regular burglars, this study aims to differentiate between offenders. Logistic regression analysis of 110 car key and 110 regular burglary offenders revealed that car key burglars are more likely to have previous vehicle theft convictions and are also more likely to be detected on information supplied to the police than regular burglars. Regular burglars are more likely to have previous shoplifting convictions. It was concluded that car key burglars are a distinct sample of offenders and the implications of these findings are discussed.