江苏泰州城市霾天和沙尘天气溶胶中细菌群落结构特征研究

近年来,空气污染已成为长三角地区最关键的环境问题之一,气溶胶颗粒物(PM)是最主要的污染物之一.生物气溶胶作为颗粒物的重要组成部分,可能对空气质量和人体健康产生不利影响.利用高通量测序方法研究了江苏省泰州2019年11月至2020年1月期间发生沙尘和霾污染时生物气溶胶中细菌群落结构组成特征.结果表明:冬季沙尘天和霾天气...     

北京市空气质量及其与能源消费结构的动态关联

运用模糊集理论中的Euclidean权距离评价2002—2011年北京市空气质量。根据最大隶属度原则确定空气质量等级值,结合灰色系统理论中的关联动态矩阵分析法,研究北京市主要大气污染物与9种能源消费因子的动态关系。结果表明,2002、2004—2007年北京市空气质量处于Ⅲ级,2003、2008—2011年处于Ⅱ级,空气质量由劣到优的年份排序为2002、2011、2010、2006、2007、2009、2008、2005、2004、2003年,2003、2008年空气质量得到改善,2009年以来有所恶化;燃料油、焦炭和煤炭是造成北京市大气污染的前3位能源,天然气是最清洁的能源;同种能源与不同污染物的关联程度相似;同种能源与污染物在不同时间段的关联序基本不变,不同能源因子分别表现出"缓慢上升"、"逐渐升高"、"水平S"型和"倒U"型4种态势;燃料油与大气污染物"同增同减",大气污染物与燃料油正相关;天然气与大气污染物"此涨彼消",天然气与大气污染物负相关。     

Mie散射中递推方法的比较

比较了Mie理论计算中的3个递推公式,既正向递推公式、倒递推公式和赵递推公式,分析了3个公式计算归一化消光截面、散射截面和后向散射截面的收敛性能,发现正向递推公式的3种散射截面当x较大时都会出现发散现象,而倒递推公式和赵递推公式都收敛,另外也分析了截断项数的容错性,分析表明赵递推公式对截断项数有最好的鲁棒性.通过上述分...     

An ecological framework for contextualizing carnivore–livestock conflict

Carnivore predation on livestock is a complex management and policy challenge, yet it is also intrinsically an ecological interaction between predators and prey. Human–wildlife interactions occur in socioecological systems in which human and environmental processes are closely linked. However, underlying human–wildlife conflict and key to unpacking its complexity are concrete and identifiable ecological mechanisms that lead to predation events. To better understand how ecological theory accords with interactions between wild predators and domestic prey, we developed a framework to describe ecological drivers of predation on livestock. We based this framework on foundational ecological theory and current research on interactions between predators and domestic prey. We used this framework to examine ecological mechanisms (e.g., density-mediated effects, behaviorally mediated effects, and optimal foraging theory) through which specific management interventions operate, and we analyzed the ecological determinants of failure and success of management interventions in 3 case studies: snow leopards (Panthera uncia), wolves (Canis lupus), and cougars (Puma concolor). The varied, context-dependent successes and failures of the management interventions in these case studies demonstrated the utility of using an ecological framework to ground research and management of carnivore–livestock conflict. Mitigation of human–wildlife conflict appears to require an understanding of how fundamental ecological theories work within domestic predator–prey systems.     

Effects of mobile phone use on driving performance in a multiresource workload scenario

Objective: This study explores the influence of mobile phone secondary tasks on driving from the perspective of visual, auditory, cognitive, and psychomotor (VACP) multiple resource theory, and it is anticipated to benefit the human-centered design of mobile phone use while driving.

Methods: The present study investigated 6 typical phone use scenarios while driving and analyzed the effects of phone use distractions on driving performance. Thirty-six participants were recruited to participate in this experiment. We abandoned traditional secondary tasks such as conversations or dialing, in which cognitive resources can become interference. Instead, we adopted an arrow secondary task and an n-back delayed digit recall task.

Results: The results show that all mobile phone use scenarios have a significant influence on driving performance, especially on lateral vehicle control. The visual plus psychomotor resource occupation scenario demonstrated the greatest deterioration of driving performance, and there was a significant deterioration of driving speed and steering wheel angle once the psychomotor resource was occupied.

Conclusions: Phone use distraction leads to visual, cognitive, and/or motor resource functional limitations and thus causes lane violations and traffic accidents.     

Kinetic mechanism and effects of molecular structure on thermal hazards of azo compounds

In this paper, the kinetic mechanism of AIBN, AMBN, and ABVN was proposed, and the effect of molecular structure on their thermal hazards based on the kinetic mechanism was investigated. Calculated by non-isothermal DSC datum, the kinetic mechanism of AIBN, AMBN, and ABVN is revealed by the linear relationship between the integrated form of mechanical function and reaction time. The results indicate that the thermal decomposition process is controlled by the Johnson-Mehl-Avrami equation. Based on the determination of kinetic mechanism function, the reaction rate constants at various heating rates are directly calculated, and the intercept of the best fitting straight line of reaction rate constants with heating rate is approximately equal to the reaction rate constant under isothermal conditions. Besides, theoretical values obtained by multiplying kinetic mechanism function by reaction rate are well consistent with the experimental values, suggesting that the kinetic mechanism obtained is credible. Bond Dissociation Energies (BDE) calculated by quantum chemical equations are employed to evaluate the thermodynamics stability of AIBN, AMBN, and ABVN. Depending on similar molecular structures, the influence of differentiated group structure on the thermodynamic stability represented by BDE and heat release and the kinetic stability characterized by reaction rate constant were revealed. Finally, the results demonstrate that the thermal hazard increases as the volume of substituent group and molecular weight.     

Occupational injury rates among Norwegian farmers: A sociotechnical perspective

Introduction: This study addressed relative injury risk among Norwegian farmers, who are mostly self-employed and run small farm enterprises. The aim was to explore the relative importance of individual, enterprise, and work environment risks for occupational injury and to discuss the latent conditions for injuries using sociotechnical system theory. Method: Injury report and risk factors were collected through a survey among Norwegian farm owners in November 2012. The response rate was 40% (n = 2,967). Annual work hours were used to calculate injury rates within groups. Poisson regression using the log of hours worked as the offset variable allowed for the modeling of adjusted rate ratios for variables predictive of injury risk. Finally, safety climate measures were introduced to assess potential moderating effects on risk. Results: Results showed that the most important risk factors for injuries were the design of the workplace, type of production, and off-farm work hours. The main results remained unchanged when adding safety climate measures, but the measures moderated the injury risk for categories of predominant production and increased the risk for farmers working with family members and/or employees. An overall finding is how the risk factors were interrelated. Conclusions: The study identified large structural diversities within and between groups of farmers. The study drew attention to operating conditions rather than individual characteristics. The farmer’s role (managerial responsibility) versus regulation and safety climate is important for discussions of injury risk. Practical Applications: We need to study sub-groups to understand how regulation and structural changes affect work conditions and management within different work systems, conditioned by production. It is important to encourage actors in the political-economic system to become involved in issues that were found to affect the safety of farmers.     

Perceived barriers to and drivers of community participation in protected‐area governance

Protected areas (PAs) are a frequently used conservation strategy, yet their socioeconomic impacts on local communities remain contentious. A shift toward increased participation by local communities in PA governance seeks to deliver benefits for human well‐being and biodiversity. Although participation is considered critical to the success of PAs, few researchers have investigated individuals’ decisions to participate and what this means for how local people experience the costs and benefits of conservation. We explored who participates in PA governance associations and why; the perceived benefits and costs to participation; and how costs and benefits are distributed within and between communities. Methods included 3 focus groups, 37 interviews, and 217 questionnaire surveys conducted in 3 communities and other stakeholders (e.g., employees of a nongovernmental organization and government officials) in PA governance in Madagascar. Our study design was grounded in the theory of planned behavior (TPB), the most commonly applied behavior model in social psychology. Participation in PA governance was limited by miscommunication and lack of knowledge about who could get involved and how. Respondents perceived limited benefits and high costs and uneven distribution of these within and between communities. Men, poorer households, and people in remote villages reported the highest costs. Our findings illustrate challenges related to comanagement of PAs: understanding the heterogeneous nature of communities; ensuring all households are represented in governance participation; understanding differences in the meaning of forest protection; and targeting interventions to reach households most in need to avoid elite capture.     

基于拓展TPB理论的客舱不安全行为意向影响因素研究

为了探究客舱旅客产生不安全行为意向的影响因素,本文基于旅客个体行为不完全受意志控制的特点,提出了采用计划行为理论作为理论基础,并引入了过去行为、风险感知和情绪管理3个新变量,构建了拓展的计划行为理论模型。通过自制量表的方式,研究了客舱旅客不安全行为意向影响因素的12个假设。研究结果表明,行为态度是影响不安全行为意向的最大直接因素,风险感知是最大的间接因素。本文为干预和引导旅客的安全行为给出一定的理论依据。     

空气污染视角下北京市产业结构调整的政策模拟研究

空气污染问题是制约经济社会健康发展的重要因素,产业结构调整是缓解该问题的重要途径,探究产业结构调整对于空气污染问题的改善效应具有重要的意义。本文以环境保护和经济增长为双重目标,以投入产出理论为基础,构建了一个一般的具有政策权重的产业结构双目标优化模型。模型目标中的权重体现了政策对两个目标的倾向性需求。给定了某种政策权重,就能根据优化模型计算出最优的产业结构。进一步,我们以SO 2的排放量作为环保指标,以GDP作为经济指标,利用上述模型,依据实际数据,在不同政策权重下,对北京市2017年的产业结构进行了模拟测算,从而给出了与之对应的北京市最优化的产业结构调整方案。特别地,选择了其中三种政策倾向力度,即经济增长偏向性政策、中性政策、环境保护偏向性政策方案,分别给出了最优产业结构方案的数量结果和两个目标的值。我们注意到,2017年的实际值与2016年的实际值相比,2017年的污染物SO 2的排放量大幅减少,且GDP也有所增加,这表明了政府部门的政策相对有效。但是,我们计算出的三种最优化的产业结构对应的两个目标值均优于2017年实际值。事实上,对于经济偏向性政策,最优化的产业结构使得GDP的数量上升更多,而SO 2的排放量也减少了不少;即使是采用环保偏向性政策,不仅使污染物SO 2的排放量更少,而且使GDP的数量仍然高于2017年的实际值。这说明本文提出的通过优化产业结构实现环境保护是一个可行的、合理的途径。