二乙酰吗啡盐酸盐标准物质的研制（1）—均匀性和稳定性检验

目的研制二乙酰吗啡盐酸盐标准物质,并检验其均匀性和稳定性。方法采用中压快速纯化制备系统分离纯化海洛因样品得到二乙酰吗啡盐酸盐,确认其结构后,采用统计学方法进行均匀性检验和稳定性检验。结果二乙酰吗啡盐酸盐标准物质含有0.88个结晶水,其瓶间不均匀性产生的标准不确定度为0.29%,短期和长期稳定性的标准不确定度分别为0.04%和0.46%。结论研制的二乙酰吗啡盐酸盐标准物质均匀性和稳定性良好。     

远近夹持方式对凸齿钥匙上仿形刀痕迹倾斜角度的影响

目的 探索远近两种夹持方式对凸齿钥匙上仿形刀痕迹倾斜角度的影响.方法 用铝板制作相同坡长、不同齿坡角的凸齿钥匙模型,在远近两种夹持方式下模拟增配过程,观察并总结钥匙上仿形刀痕迹倾斜角度的变化.结果 两种夹持方式下的仿形刀痕迹倾斜角相等.结论 远近夹持不影响仿形刀痕迹倾斜角度.     

真空镀膜中膜系选择对潜手印显现的影响

目的探究在真空镀膜中不同镀膜材料能否显现出潜手印并比较不同镀膜金属显现手印的效果。方法使用不同的镀膜金属显现多种类型客体表面的潜手印。结果存在可替换镀膜材料。结论可替换镀膜金属对潜手印显现的效果良好,纹线清晰连贯,背景反差大,并对特定客体上的手印显现极具优势。     

自含墨印章印文盖印时间受老化条件的影响

目的探索利用气相色谱法较精确、定量测定自含墨印章印文盖印时间受人为老化条件的影响。方法分别在恒温烘烤、紫外线照射、纯水浸泡等人为老化条件下,测定自含墨印章印油中所含有的主要相关溶剂成份的含量变化。结果得出了主要溶剂成份在人为老化条件下其含量的变化规律以及人为老化与自然老化的对应关系。结论利用气相色谱法可以对不同保存条件下自含墨印章印文的盖印时间进行测定,为实际相关案件的检验提供了依据。     

物联网及无线定位技术在物证管理中的应用

物证监控信息化管理系统发展大趋势是智能化,综合利用物联网RFID技术可对物证进行智能化识别、登记、使用、监控以及生命周期管理等;应用RFID与ZigBee相结合的室内无线定位技术,可实现自动获取、管理物证实时可控的状态信息,防止物证被盗或丢失,提高管理和维护效率。     

Local plant use and traditional conservation practices in Nhema communal area,Zimbabwe

Abstract

This article is based on a study that was carried out in Nhema communal area in Midlands Province, Zimbabwe, with the main objective of documenting local plant use and traditional conservation practices. Data collected through household semi-structured and open interviews showed that 46 plant species in 40 genera and 24 families were mainly used for firewood, construction wood, food and traditional medicine. Other minor uses included using plant species for making mats, rope and shading. Firewood and construction wood ranked as the most important tree products used. The preferred plant species included: Julbernardia globiflora (Mutondo); Brachystegia spiciformis (Musasa); Terminalia sericea (Mususu); Brachystegia boehmii (Mupfuti); Combretum imberbe (Mutsviri); Combretum molle (Mubondo) and Burkea africana (Mukarati). Some of the highly preferred species, considered to be declining in the local environment, included Adenium obesum (Chisvosve); Azanza garckeana (Mutohwe); Brachystegia boehmii (Mupfuti); Brachystegia spiciformis (Musasa); Burkea africana (Mukarati); Combretum imberbe (Mutsviri); Combretum molle (Mubondo); Dalbergia melanoxylon (Mukonashanhu); Diospyros mespiliformis (Musuma); Elephantorrhiza goetzei (Ntorani); Julbernardia globiflora (Mutondo); Phragmites australis (Shanga; Poulzozia hypoleuca (Munanzwa); Pterocarpus angolensis (Mubvamaropa); Terminalia sericea (Mususu) and Uapaca kirkiana (Muzhanje). Highly preferred and declining species were characteristically large trees and shrubs. Local people are aware of the need to conserve plant resources in order to protect the environment and avoid the extinction of these rare species.Traditional conservation practices have substantially contributed to the conservation of plant species in Nhema communal area. The protection of indigenous timber, fruit trees, trees with social and cultural significance, the use of deadwood for firewood, the use of eucalyptus trees as construction wood and the occurrence of sacred woodland areas represented some of the traditional conservation techniques employed in Nhema communal area. These local practices demonstrate the dynamism and significance of African indigenous knowledge systems.     

Lead Theft—A Study of the “Uniqueness” of Lead from Church Roofs

In the United Kingdom, theft of lead is common, particularly from churches and other public buildings with lead roofs. To assess the potential to distinguish lead from different sources, 41 samples of lead from 24 church roofs in Northamptonshire, U.K, have been analyzed for relative abundance of trace elements and isotopes of lead using X‐ray fluorescence (XRF) and inductively coupled plasma mass spectrometry, respectively. XRF revealed the overall presence of 12 trace elements with the four most abundant, calcium, phosphorus, silicon, and sulfur, showing a large weight percentage standard error of the mean of all samples suggesting variation in the weight percentage of these elements between different church roofs. Multiple samples from the same roofs, but different lead sheets, showed much lower weight percentage standard errors of the mean suggesting similar trace element concentrations. Lead isotope ratios were similar for all samples. Factors likely to affect the occurrence of these trace elements are discussed.     

人体组织/体液来源的法医学鉴定

生物检材的组织/体液来源鉴定是法医学检验的重要内容之一。法医学组织/体液鉴定的方法较多,无论是基于酶促反应或免疫学检测的传统鉴定方法,还是光谱法或近年来基于mRNA、microRNA或DNA甲基化差异的分子生物学组织鉴定技术,均各有特点。本文就各种法医学组织/体液鉴定方法的特点及其法医学应用价值作一简要综述。     

Forensic Comparison of Soil Samples Using Nondestructive Elemental Analysis

Soil can play an important role in forensic cases in linking suspects or objects to a crime scene by comparing samples from the crime scene with samples derived from items. This study uses an adapted ED‐XRF analysis (sieving instead of grinding to prevent destruction of microfossils) to produce elemental composition data of 20 elements. Different data processing techniques and statistical distances were evaluated using data from 50 samples and the log‐LR cost (C_llr). The best performing combination, Canberra distance, relative data, and square root values, is used to construct a discriminative model. Examples of the spatial resolution of the method in crime scenes are shown for three locations, and sampling strategy is discussed. Twelve test cases were analyzed, and results showed that the method is applicable. The study shows how the combination of an analysis technique, a database, and a discriminative model can be used to compare multiple soil samples quickly.     

Recovery of Trace DNA on Clothing: A Comparison of Mini‐tape Lifting and Three Other Forensic Evidence Collection Techniques

Trace DNA is often found in forensic science investigations. Experience has shown that it is difficult to retrieve a DNA profile when trace DNA is collected from clothing. The aim of this study was to compare four different DNA collection techniques on six different types of clothing in order to determine the best trace DNA recovery method. The classical stain recovery technique using a wet cotton swab was tested against dry swabbing, scraping and a new method, referred to as the mini‐tape lifting technique. Physical contact was simulated with three different “perpetrators” on 18 machine‐washed garments. DNA was collected with the four different DNA recovery methods and subjected to standard PCR‐based DNA profiling. The comparison of STR results showed best results for the mini‐tape lifting and scraping methods independent of the type of clothing. The new mini‐tape lifting technique proved to be an easy and reliable DNA collection method for textiles.