头发对射击残留物附着的影响

利用射击残留物的存在和分布形态判断枪口与射入口的距离是现场分析的关键之一。然而我们在工作中发现,在对头部射击的案件中,弹孔周围的头发有可能对射击残留物起到屏蔽作用,尤其在贴近距离[1](2cm~5cm左右)射击的时候,绝大部分射击残留物会附着在头发而不是头皮上,本文将以实验和真实案例为基础详细说明近距离射击时头发对射击残留物附着的影响。     

The Green New Deal Must Preserve the Existing Nuclear Fleet

Abstract

As the largest source of carbon-free energy in the United States, nuclear energy must play a vital role in reducing emissions. This article suggests the Green New Deal, an ambitious federal proposal to address climate change, should aim to preserve the existing nuclear fleet by authorizing states to establish zero emission credit (“ZEC”) programs. The ZEC programs will provide credits, in the form of revenue, for the carbon-free attribute of nuclear energy. This article posits the ZEC programs should be based on a model ZEC program developed by the Federal Energy Regulatory Commission and explicitly authorized by amendment of the Federal Power Act to avoid issues of preemption.     

酮洛芬注射液在乳牛体内的残留消除研究

为建立牛乳中酮洛芬的液相色谱-串联质谱(LC-MS/MS)检测方法,牛乳样品经甲醇提取,C18色谱柱分离,采用正离子模式,多反应监测,内标法定量。结果表明,牛乳中酮洛芬的检出限为1μg/kg,定量限为5μg/kg,在5~200μg/kg范围内线性关系良好,相关系数大于0.99。在25~100μg/kg添加水平的回收率为93.3%~107.5%,批内、批间相对标准偏差分别为1.72%~5.46%、1.13%~7.04%。该方法高效、灵敏、准确,可作为牛乳中酮洛芬的检测方法。选用20头健康的泌乳期荷斯坦乳牛,高产、低产各10头,以3 mg/kg剂量肌内注射给药,每天1次,连用3 d,分别于每次给药后第2、15小时采集乳样。每次给药后2 h牛乳中可检出酮洛芬,最高质量分数为(38.43±3.90)μg/kg,停药后15 h均未检出。所有时间点牛乳中酮洛芬质量分数的实测结果均低于加拿大规定的最高残留限量50μg/kg,建议弃乳期为0 d。     

Combined Collection and Analysis of Inorganic and Organic Gunshot Residues

Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid^® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.     

Prevalence of organic gunshot residues in police vehicles

The present study investigated the organic gunshot residue (OGSR) background level of police vehicles in Switzerland. Specimens from 64 vehicles belonging to two regional police services were collected and analysed by LC-MS in positive mode. The driver’s and back seats were sampled separately to monitor potential differences between locations and to assess the risks of a suspect being contaminated by OGSR during transportation to a police station.The results showed that most of the 64 vehicles were uncontaminated (44 driver’s seats and 38 back seats respectively). Up to six of the seven targeted compounds were detected in a single sample, once on a driver’s seat and twice on back seats. The contamination frequency generally decreased as the number of compounds detected together increased. The amounts detected were in the low ng range and less than amounts generally detected just after discharge on a shooter. Our data indicated that detecting a combination of four or more compounds on a police vehicle seat appears to be a relatively rare occurrence. The background contamination observed was most probably due to secondary transfer from police officers (e.g. through recent participation in a shooting session or firearm manipulation) or from firearms stored in the vehicles. The present results might be used as a recommendation to minimize contact of a suspect with contaminated surfaces if OGSR is implemented in routine work in parallel to IGSR analysis.     

Carbon sink geopolitics

Abstract

This paper explores an example of global politics in action by attending to the modalities and outcomes of United Nations negotiations on global warming. More precisely, the paper ethnographically traces how the capacity of tropical forests to act as carbon sinks is turned into a matter of global concern. The focus is on a negotiated policy called Reducing Emissions from Deforestation and forest Degradation (REDD+) and its anchoring in the Democratic Republic of the Congo, whose territory contains the second largest area of rainforest after Brazil. The paper discusses the importance of the promissory in climate actions, the multivalence of what is at stake and the porosity and resilience of national demarcation. To do so, it identifies three moments and sites of geopolitical re-composition: the formulation of international consensus, the work of preparatory agents and the quest for metrological inclusiveness. These moments and sites point to the theatricality and semi-secrecy of United Nations negotiations, the mobilizing activities of expatriate consultants hired with overseas aid funding and the unstable evidential grounds on which emission reduction efforts are based. The paper suggests that, through this series of processes, the carbon stored by tropical forests becomes a matter of global exigency.     

The political economy of ‘flex trees’: a preliminary analysis

With the rise of ‘bioeconomy’, trees are receiving increasing attention. This contribution conducts a preliminary analysis of the trajectories and the main drivers of change in the rise of new, flexible and multiple uses of trees. It assesses the political dimensions involved in this transformation, which is simultaneously ongoing, anticipated and imagined. Notes are offered on the issues to be considered when the flex-crop framework is operationalized to include the study of trees, and additional conceptualizations that help in analyzing the political economy of tree uses are provided. Areas needing further empirical study are identified and a preliminary research agenda is suggested. The flexible and multiple use of trees and tree-derived commodities is having a large impact on power relations in the global political economy of forestry and the forest industry, the asymmetry of which is based on who is best able to flex or de-multiply, thereby controlling commodity webs and processing technology. It is argued that while flexing seems to increase diversity, in practice it typically increases this only for the processing industry; the converse occurs in terms of the unification of the productive base into monocultures. However, these two processes go hand in hand, and illustrate how flexing is a deeply capitalist process.     

“于正剧现象”研究

"于正剧现象"的特征是"叫座不叫好"。这种类型的电视剧违背艺术真实的美学原则,文本中充满大量的虚假情节、虚假人物、虚假环境、虚假道具。既不符合直观真实或超现实真实,又不符合主观真实,更难以达到客观真实的美学高度,是一种典型的高碳艺术。大力开发符合艺术真实,特别是实现客观真实的低碳艺术,这是中国电视剧艺术发展的正确方向。     

低碳视角下生态文明城市建设路径研究——以贵阳市为例

2007年12月29日,贵阳市委通过了《中共贵阳市委关于建设生态文明城市的决定》,举全市之力在各个领域进行生态文明城市建设。当前,低碳经济不仅是国内外研究的热门话题,也是国内外经济社会领域实践的热点话题。为了应对日益严峻的温室效应,各国各地区选择了低碳经济的道路。低碳经济是建设生态文明城市的突破口,又可以将生态文明城市建设向纵深推进。     

Green grabs and biochar: Revaluing African soils and farming in the new carbon economy

Biochar currently attracts technological and market optimism, promising multiple wins – for climate change, food security, bioenergy and health – not least for African farmers. This paper examines the political-economic and discursive processes constructing biochar as a novel green commodity, creating new alliances amongst scientists, businesses, venture capital firms and non-governmental organisations. Carbon market logics are not only threatening large-scale land grabs for biochar feedstocks but also other forms of resource, labour and ecological appropriation through driving research and development and shaping small-scale pilot projects. In these, soil carbon is ‘chopped out’ of its ecosystem and social contexts and revalued as exchangeable pieces of carbon nature. Farmers are hailed as green actors and market winners, provided they discipline their practices according to these new technical and market logics. These discourses contrast strongly with the farmers' existing conceptual and practical repertoires; a case study from Liberia illustrates how farmers already manipulate soil carbon in creating locally valued anthropogenic dark earths, but within diverse farming repertoires, ontologies of human–nature interrelationship and historical and political ecologies.