应用SEM/EDX和ICP-AES检测元素成份判定致伤工具

目的应用扫描电镜/能谱联合分析仪(Scanning electron microscopy & Energy dispersive X-ray apparatus SEM/EDX)和电感耦合原子发射等离子光谱(inductively coupled plasma-atom emission spectrometer ICP-AES)对金属致伤工具本身及所致创口残留物元素成分分析,探讨两者在推断认定此类工具的应用条件及价值.方法镀层和普通铁质工具在乳猪皮肤各致创5例,SEM/EDX对创口内遗留金属颗粒元素检测;用标准样品检测实验方法的精确度;普通铁质工具于刀背、刀刃处各取5个样本,ICP-AES测定元素成分与含量.结果镀锌工具所致创口中存在单一含有锌的金属颗粒,镀黄铜工具则同时含有锌和铜,未发现其它元素;不锈钢或普通铁质菜刀创口中,发现同时含有铁、铬、硅或铁、锰、硅的颗粒;除5号菜刀外同一把铁质菜刀在刀刃、刀背处元素含量无明显差别;ICP-AES分析表明不锈钢菜刀之间在铬、锰、硅、铜、钼和5号刀背部以及其他铁质菜刀在锰、硅元素含量差别具有显著意义,5号刀刃部锰、硅、钼、钛、磷、硫、镍元素RSD明显升高.结论SEM/EDX可以通过创口的检测对金属致伤工具进行种类的推断认定,ICP-AES则可在同种类致伤工具中进行相对同一的判定有应用价值.     

采用SEM/EDX方法推断铜锌镀层钢管的种类

目的采用扫描电镜/X射线能谱仪(SEM/EDX)法推断铜锌镀层钢管的种类,评价其在推断工具种类认定中的意义。方法用3根铜锌镀层钢管打击滤纸和猪皮后,分别提取残留的金属颗粒各5组,使用扫描电镜/X射线能谱仪颗粒分析方法进行检测,用SPSS 13.0软件对所得铜锌颗粒成分数据进行统计学分析。结果通过Cu和Zn元素相对含量的均数±标准差(x—±s),评估铜锌镀层钢管打击滤纸和猪皮后所残留的铜锌元素金属颗粒的稳定性。不同种类钢管残留金属颗粒成分(P0.05)有显著差异,同一把钢管打击猪皮和滤纸残留金属颗粒(P0.05)无差异。结论 SEM/EDX颗粒分析方法可以对铜锌镀层钢管进行种类认定。     

应用SME/EDX和ICP-AES检测元素成份判定致伤工具

目的应用扫描电镜／能谱联合分析仪(Scanning electron microscopy&Energy dispersive X-ray apparatus SEM／EDX)和电感耦合原子发射等离子光谱(inductively coupled plasma-atom emission spectrometer ICP-AES)对金属致伤工具本身及所致创口残留物元素成分分析，探讨两者在推断认定此类工具的应用条件及价值。方法镀层和普通铁质工具在乳猪皮肤各致创5例，SEM／EDX对创口内遗留金属颗粒元素检测；用标准样品检测实验方法的精确度；普通铁质工具于刀背、刀刃处各取5个样本，ICP-AES测定元素成分与含量。结果镀锌工具所致创口中存在单一含有锌的金属颗粒，镀黄铜工具则同时含有锌和铜，未发现其它元素；不锈钢或普通铁质菜刀创口中，发现同时含有铁、铬、硅或铁、锰、硅的颗粒；除5号菜刀外同一把铁质菜刀在刀刃、刀背处元素含量无明显差别；ICP-AES分析表明不锈钢菜刀之间在铬、锰、硅、铜、钼和5号刀背部以及其他铁质菜刀在锰、硅元素含量差别具有显著意义，5号刀刃部锰、硅、钼、钛、磷、硫、镍元素RSD明显升高。结论SEM／EDX可以通过创口的检测对金属致伤工具进行种类的推断认定，ICP-AES则可在同种类致伤工具中进行相对同一的判定有应用价值。     

铁铬合金菜刀遗留金属颗粒的成分评价方法

目的检测铁铬合金菜刀遗留的金属颗粒成分,并建立可行的评价指标及方法。方法使用滤纸擦蹭菜刀制作金属遗留微小颗粒样本,应用扫描电镜-X射线能谱仪(scanning electron microscopy and energy dispersive X-ray spectrometer,SEM-EDX)的GSR颗粒分析功能检测遗留金属颗粒成分,计算遗留金属颗粒中铁、铬相对含量比。结果铁铬合金菜刀遗留金属颗粒内所含铁、铬相对含量比,在大部分菜刀间差异有统计学意义(P0.05)。结论使用GSR颗粒分析功能量化检测铁铬合金菜刀遗留金属颗粒内铁、铬相对含量比,为此类致伤工具的认定建立可行的评价方法。     

两种铁铬合金电警棍遗留金属颗粒成分分析

目的检测两种电警棍铁铬合金电极遗留金属颗粒的成分,对同一电警棍电击前后遗留金属颗粒成分特征进行分析,对电警棍遗留金属颗粒成分的稳定性、差异性进行评价。方法使用电警棍分别多次摩擦滤纸和电击猪皮,使用碳导电胶带粘取遗留金属颗粒,应用SEM/EDS技术检测颗粒元素成分,并对数据进行统计学分析。结果两种电警棍电击前遗留铁铬合金颗粒及电击后遗留铁铬合金颗粒成分均稳定,存在差异;实验两种电警棍电击后遗留金属颗粒成分分布发生显著变化,除原成分铁铬颗粒外,实验猪皮表面均检出全新成分的铁铬合金颗粒,且两种电警棍电击后产生的全新铁铬颗粒成分稳定无显著差异。结论通过分析两种电警棍铁铬电极电击前后遗留多金属颗粒成分分布特征,可以实现对两种电警棍电极的识别,为人体电警棍损伤的识别与认定提供技术支持和理论依据。     

人体骨骼上菜刀痕迹的检验及同一认定

目的 对人体骨骼上刀痕进行致伤工具同一认定的检验和研究.方法 用同一把菜刀的相同部位分别砍击骨骼与新鲜灌木,通过对骨骼上刀痕进行组织学处理以显现致伤工具的痕迹,并使用比对显微镜将骨骼与灌木上的砍痕进行比对,分析骨质断面的痕迹特征.结果 菜刀在骨骼上形成的砍切痕迹线条与比对样本的砍切痕迹线条可以完全拼接.结论 显微镜下可直观、清晰地观察到致伤工具在骨骼上留下的痕迹,为致伤工具的推断提供了新的方法.     

钢锤打击后皮肤遗留金属颗粒成分检测

目的应用扫描电镜-X射线能谱仪(scanning electron microscope and energy dispersive X-ray spec-trometer,SEM-EDX)对钢锤打击猪皮和滤纸遗留金属颗粒进行元素成分分析,为钝器致伤工具推断研究建立方法。方法使用两把不同的钢锤分别打击猪皮和滤纸,应用SEM-EDX检测遗留金属颗粒,利用SPSS13.0对检测结果进行统计分析。结果同一把钢锤多次打击遗留颗粒成分特征稳定,打击猪皮和滤纸遗留颗粒成分差异无统计学意义,两把成分不同的钢锤遗留颗粒成分差异有统计学意义。结论 SEM-EDX可以对钢锤遗留的颗粒进行成分检验,为法医学致伤物推断提供新的途径。     

垂直抛甩状血迹形态的模拟观察

目的观察不同类型打击工具的垂直抛甩状血迹形态。方法选择常见的菜刀、匕首、方锤、铁管作为打击工具。用沾新鲜鸡血5 m L的工具自上而下进行垂直抛甩,对距离垂直墙壁30 cm处形成的血迹形态进行测量分析,通过对抛甩血迹的整体分布特征(跨度、宽度、密度)、起始血迹的形态特征(长度、宽度、接触角度)进行分析。结果匕首形成抛甩血迹的分布跨度最小(P0.05);在整体分布宽度上,菜刀最小(P0.05);在整体分布密度上,除菜刀与方锤之间差异无统计学意义,其他工具两两之间差异均有统计学意义(P0.05)。方锤较其他三种工具在起始血迹点长度上最长(P0.05);菜刀与方锤、匕首与方锤在起始血迹点宽度上差异有统计学意义(P0.05)。结论每一类型的打击工具所形成的垂直抛甩血迹形态具有一定的特征,可用于命案现场推断打击工具的类型。     

扫描电镜/X射线能谱仪检验电流斑规范化方法探讨

目的探讨电流斑皮肤金属化的机理、检材提取处理和扫描电镜/能谱仪检验规范化方法,对检验结果进行分析和价值判断。方法用扫描电镜/能谱检验,采用低倍大窗口覆盖损伤区域采集平均元素能谱图,并在可能的金属元素富集区域寻找球形金属颗粒。结果扫描电镜下可观察到散在的孔穴、细胞碎屑、龟裂、裂隙等特征,有些电流斑可检出金属元素,其中部分电流斑可发现球形金属颗粒。结论采用规范化的检材提取、处理和检验方法可消除随意性方法造成错检的可能。电流斑皮肤上异常含量的金属附着可支持病理检验符合电流斑表现的结论,同时也为电击导体的推断和金属元素成分比对提供依据。球形金属颗粒的发现揭示存在电弧高温的可能性极大,可强力支持病理检验符合电流斑表现的结论。     

应用SEM/EDX检测皮肤上腐蚀物质元素

在某些凶杀案件中,犯罪分子为掩藏其罪行,用强酸、强碱对尸体进行毁容,然后抛尸的现象屡有发生。为确定尸源、寻找侦查线索,侦技人员必须确定毁容物质的种类或品种。但有关这方面的文献报道较少,通常是法医工作者依据经验,通过观察灼伤皮肤的形态、颜色等做出大致判断,对案件侦破提供线索或证据受到一定局限。本文应用扫描电子显微镜/能谱仪(SEM/EDX)对4种强酸、强碱腐蚀猪皮表面进行测试,通过检测皮肤上腐蚀物质的特征元素(如S,Cl,Na,K等)来推断腐蚀物质的类型,以期建立一种简便、有效的理化检验方法,为实际办案判断毁容物质类型提供信…     

Identify the injury implements by SEM/EDX and ICP-AES

The forensic investigator is frequently confronted with the discrimination and deduction of injury implements, which is one of the most important physical testimonies in courts. The usual method used in actual cases is from points of morphology. In the forensic discrimination of injury implements, such as metal implements, the analysis and comparison of elements are expected to provide excellent results, and simultaneous multi-elemental analysis is required to analyze various kinds of elements. This study was designed to establish discrimination and deduction of metal injury implements by scanning electron microscope/energy disperse X-ray microanalyzer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Examined metal particles in five wounds made on the skin of domestic pigs, respectively, using Cu-Zn or Cr-Ni coated and carbon steel kitchen implements by EDX. For carbon steel kitchen implements, analyzed five samples from the back and blade separately in the contents and varieties of elements by ICP-AES. In the wounds by the coated implements, the special particles only containing Cu, Zn or Cr, Ni were found. In the wounds by carbon steel kitchen implements, the particles containing Fe, Cr, Si or Fe, Mn, Si were found. The differences of contents of elements between the back and blade was no significant except No. 5 for carbon steel kitchen implements, and the significant differences of elements exited in Cr, Mn, Si, Cu, Mo among the stainless kitchen knives, Mn, Si among the other kitchen implements and for the blade of No. 5 knife, relative standard deviations (R.S.D.s) were significantly different in Mn, Si, Mo, Ti, S, P, Ni. Using EDX to examine the particles in wounds can deduce the categories of metal injury implements, and we can still deduce the different implements in the same category by ICP-AES.     

A method for studying knife tool marks on bone

The characteristics of knife tool marks retained on hard tissues can be used to outline the shape and angle of a knife. The purpose of this study was to describe such marks on bone tissues that had been chopped with knives. A chopping stage with a gravity accelerator and a fixed bone platform was designed to reconstruct the chopping action. A digital microscope was also used to measure the knife angle (θ) and retained V-shape tool mark angle (ψ) in a pig skull. The κ value (elasticity coefficient; θ/ψ) was derived and recorded after the knife angle (θ) and the accompanied velocity were compared with the proportional impulsive force of the knife and ψ on the bone. The constant impulsive force revealed a correlation between the V-shape tool mark angle (ψ) and the elasticity coefficient (κ). These results describe the tool marks--crucial in the medicolegal investigation--of a knife on hard tissues.     

Quantitative analysis of sharp-force trauma: an application of scanning electron microscopy in forensic anthropology.

Scanning electron microscopy (SEM) has occasionally been used by anthropologists and forensic scientists to look at morphological characteristics that certain implements leave on bone. However, few studies have addressed techniques or protocols for assessing quantitative differences between tool marks on bone made by different bladed implements. In this study, the statistical variation in cut mark width was examined between control and test samples on bone using a scalpel blade, paring knife, and kitchen utility knife. Statistically significant differences (p < .0005) were found between cut marks made by the same knife under control and test conditions for all three knife types used in the study. When the control sample and test samples were examined individually for differences in mean variation between knife types, significant differences were also found (p < .0005). While significant differences in cut mark width were found, caution should be used in trying to classify individual cut marks as being inflicted by a particular implement, due to the overlap in cut mark width that exists between different knife types. When combined, both quantitative and qualitative analyses of cut marks should prove to be more useful in trying to identify a suspect weapon. Furthermore, the application of SEM can be particularly useful for assessing many of these features.     

Similar skin lesions in victim and perpetrator caused by a knife with a serrated blade

Reported in this paper is an attack of two adolescents on a man who was killed in the fight, with several kitchen knives being used, including two with grooved and wave-grooved blades. One of the offenders held the victim tight from behind and was injured by his attacking accomplice++. A grid mark on the left side of the victim's face and the left forearm of the second offender in the back supported the assumption of a knife with simple wave profile. Skin lesions of finer structure below the left ear and on the left forearm of the victim suggested involvement of a smaller kitchen knife with groove-milled wave profile. Offender-victim position and course of offence were verified and confirmed by evaluation of these specific findings.     

The Pointed Shape of a Knife Influences Eyewitness Perception

We examined the hypothesis that a pointed knife attracts particular attention because of its pointed shape. Using a visual search task method, we asked 33 participants to search 3 × 3 matrices containing outlines of knives with pointed blades such as chef’s knives and knives with rectangular blades such as Chinese chopping knives and to determine whether the matrices contained identical or non-identical knives. The participants found a pointed knife within a background of knives with rectangular blades more quickly than under the reverse condition. This result indicates that the pointed shape of a knife has an attribute that captures human attention and suggests that the visual features of a weapon affect eyewitness perception. This research would benefit forensic investigations in countries such as Japan, where gun ownership is banned and perpetrators use knives more often than firearms.     

Characteristics of Bone Injuries Resulting from Knife Wounds Incised with Different Forces

The aim of this research was to experimentally determine the characteristics of incised bone wounds, which are commonly found in defense injuries. A specially constructed pivoting arm device was used to inflict wounds with controlled forces and direction. Five knives were selected to inflict the wounds on porcine forelimbs. Eight incised wounds were made per knife per force. A larger knife and a greater force caused longer and wider bone wounds. Comparisons of individual knives at the two forces produced varying results in the bone wounds. A correlation was seen between the force and the length (r = 0.69), width (r = 0.63), and depth (r = 0.57) of bone wounds. Serrated‐edge and nonserrated knives can be distinguished from the appearance of the wound. The outcomes may be applicable in forensic investigations to ascertain the forces associated with incised wounds and identify the specific knife used.     

对作案制式刀具的种类推断

刀具是人们日常生活中常用的工具之一，其种类繁多。功能、形状各异：同时它也是最主要的犯罪工具之一。因此。通过推断作案刀具的种类。来查找和确定犯罪嫌疑人。仍然是案件侦察中的途径之一。而本文从刀具制作行业的角度出发。对几类作案制式刀具的功能、外形结构特点、制作材料．进行了细致的研究。并从痕迹检验的角度出发。重点研究了制式刀具的痕迹形态、特点及特征反映．阐述了制式刀具种类的推断方法。     

SEM and Stereomicroscopic Analysis of Cut Marks in Fresh and Burned Bone

This study documents the prevalence of cut mark characteristics in fresh and burned domestic pig ribs. Stab wounds from single edge serrated and smooth‐edged knives were inflicted in the vertebral and sternal regions of each fresh rib. Each rack of ribs was then divided into vertebral and sternal units. Vertebral units were defleshed and their associated cut marks were examined using a stereomicroscope. Sternal units were burned in an outdoor fire pit and examined with the addition of a scanning electron microscope (SEM). Linear cuts, V‐shaped cross‐sections, mounding, hinge fractures, and wastage were all observed on burned ribs. There was an overall decrease in the prevalence of all features (up to a 40% decrease), regardless of knife type, in burned ribs. Striations within cut marks were not observed in either fresh or burned ribs. Oblique faulting and bone lifts could only be observed using the SEM. Mounding and wastage were obliterated during the burning process. Therefore, cut marks in burned bone should ideally be examined for their characteristics utilizing an SEM.