On equilibrium in resource markets with scale economies and stochastic prices

In this paper, I show the existence and the characteristics of equilibrium in a non-renewable resource market where extraction costs are non-convex and market price is subject to stochastic shocks, an empirically relevant setting. In my model firms may be motivated to hold inventories to facilitate production smoothing, which allows them to continue producing at a smooth pace at any instant when extraction ceases, e.g. when reserves are exhausted. This aspect of the model then supports a competitive equilibrium in the presence of non-convex costs. Casual empirical evidence is provided that supports the central features of my model for a variety of non-renewable resources, lending credence to the explanation for equilibrium I propose.     

全氟化合物同分异构体的环境行为及毒性效应研究进展

以全氟辛烷磺酸盐(PFOS)和全氟辛烷羧酸(PFOA)为代表的全氟化合物(PFASs)是一类新型持久性有机污染物,目前已经在全球自然环境、野生生物及人群中广泛检出,其环境与健康问题已引起人们的高度重视。传统的电氟化法生产工艺使PFASs产品存在碳链同分异构体。这些PFAS的同分异构体可能具有不同的环境行为和毒理效应。随着分析方法的逐渐成熟,目前,国外的学者已经在该研究领域进行了一些探索性的研究,并取得了一定的进展,而我国在该领域的研究相对较少。以PFOS和PFOA为例,在介绍了PFAS同分异构体的来源、命名和世界各地生产厂家的异构体组成等基本信息的基础上,还系统介绍了环境介质中PFAS同分异构体的分析方法、环境迁移转化差异及源分析研究;生物和人体的生物累积性及毒理学差异等;并对目前存在的问题进行了讨论,为今后PFAS同分异构体的环境问题研究提供相应的参考。     

基于层次分析法的电缆燃烧性能综合指标评价体系

目前对于电缆燃烧性能评价方法大多采用延燃性作为单一评价指标,但是电缆的燃烧性能还应包括生烟性、毒性和腐蚀性等方面.国内外大量试验证明锥形量热计试验结果与全尺寸试验结果相关性较好,利用锥形量热计对真实火灾情况下电缆燃烧性能进行评价较为合理.本文在锥形量热计燃烧试验基础上,构建了电缆燃烧性能综合指标评价体系,并运用层次分析法确定各指标的权重.该体系为电缆燃烧性能评价研究提供一种新的尝试,也可为以后的阻燃电缆分级体系建立提供一些参考.     

Towards a complex model of disaster behaviour

This paper outlines why a move towards a complex adaptive systems model of behaviour is required if the goal is to generate better understanding of how individuals and groups interact with their environment in a disaster setting. To accomplish this objective, a bridge must be built between the broader social sciences and behavioural economics to incorporate discipline‐specific insights that are needed to move towards complexity. This is only possible through a deeper understanding of behaviour and how the environment in which they occur can influence actions. It is then that one can counteract the poor behavioural predictions, flawed policies based on myth, inefficient design, and suboptimal outcomes that have flourished in the absence of a complex adaptive systems model. This paper provides a conceptual framework that draws on concepts from across the natural and social sciences, such as behavioural economics, endocrinology, psychology, sociobiology, and sociology in order to build an interactive theory of disaster behaviour.     

大型环境监测实验室分析仪器绩效评估指标体系探索

大型环境监测实验室分析仪器是环境监测单位综合实力的集中体现,在环境监测工作中发挥着巨大作用。简述了仪器设备绩效评估研究现状,尝试构建大型环境监测实验室分析仪器绩效评估指标体系,并通过德尔菲法确定各项评价指标的权重值,最终计算绩效评估综合指数。在此基础上,对某省级环境监测机构的部分大型实验室分析仪器进行分析,提出,需合理配置仪器、加强日常维护管理以及开放共享等建议,为提高大型环境监测实验室分析仪器的精细化管理提供了科学依据。     

恶臭污染分析及防治技术

恶臭是一种感觉公害,其产生的嗅觉危害人的身体健康和生活的安宁舒适。阐述了恶臭来源、分类,提出了分析和防治方法,重点介绍了适于自动化控制的光、电化学技术。     

纯氧曝气在城市污水处理中的经济性比较

就城市污水处理工艺中鼓风曝气系统和纯氧(或富氧)曝气系统,从原理、技术性指标等方面进行了分析和比较,显然纯氧曝气系统比鼓风曝气系统具有一定的优越性。在城市污水处理厂老厂改造和新厂建设中采用纯氧曝气法具有良好的前景。     

Economics analysis of food waste treatment in China and its influencing factors

• Economics of food waste treatment projects at 29 pilot cities in China was examined. • Roles of location, population size, processing technique, and income were studied. • Economic benefits were limited with a profit to cost ratio of 0.08±0.37. • Service population size affects construction economics significantly (P = 0.016). • Choice of food waste processing technique affects operating economics notably. This study examines the economic benefits of food waste treatment projects in China and factors affecting them. National-level pilot projects for food waste treatment located in 29 cities were selected as samples. The economics of food waste recycling from the investors’ perspective, in terms of investment during the construction phase and cost and benefit during the operation phase, was assessed. Results indicate that the average tonnage investment of food waste treatment projects was RMB 700.0±188.9 thousand yuan, with a profit to cost ratio of 0.08±0.37. This ratio increased to 0.95±0.57 following the application of government subsidies. It highlights the limited economic benefits of food waste treatment facilities, which rely on government subsidies to maintain their operations in China. Further analysis using a multi-factor analysis model revealed that regional location, service population size, processing techniques, and urban income exerted varying impacts on the economy of food waste treatment. Population size exerted the highest impact (P = 0.016) during the construction stage, and processing techniques notably influenced the project economy during the operation stage. The study highlights the need to prioritize service population size and processing techniques during economic decision-making and management of food waste recycling projects. The results of this study can serve as a valuable practical reference for guiding future policies regarding food waste treatment and related planning.     

完善排污许可制度体系,全面服务生态环境质量改善

《排污许可管理条例》的颁布,标志着以排污许可制为核心的固定污染源监管制度体系建设进入法治化发展的新阶段。当前应以《排污许可管理条例》的实施为契机,在抓好排污许可证数量的基础上狠抓质量提高,坚持走好精细化、科学化和信息化发展道路;在建立基本制度的基础上建成核心制度,推动排污许可制与环评、总量控制、生态环境统计、监督执法等相关生态环境监管制度的系统联动,扩大排污单位、环境要素覆盖面,强化固定污染源"一证式"执法监管和贯穿全周期监管,全面服务生态环境质量改善。     

基于Esteban-Marquillas拓展模型的中国农业增长的演进特征

论文基于偏离-份额法的Esteban-Marquillas拓展模型,从份额分量、结构分量、净竞争分量和资源配置分量4方面系统研究了1985—2014年间中国农业生产规模及结构的演进特征。结果表明：1）研究期间,中国农业增加值呈现阶段式增长,种植业和牧业是导致农业增长的主要产业,黄淮海区和长江中下游区是全国农业增长的主要区域。2）八大粮食生产区农业产业份额分量均表现出先剧烈波动、后稳步增长的发展态势;各区域产业结构优势总体较弱且进一步下降;净竞争分量变化具有波动性,种植业、渔业促进区域农业总体竞争力的作用增强,林业和牧业的促进作用减弱;种植业和林业改善区域农业资源配置效应的作用增强,牧业和渔业则相对减弱。3）建议各区域结合产业发展优势,制定相关政策加强区域资源整合、农产品流通与技术合作,促进地区农业稳定发展。研究结果可为我国农业生产结构优化及差异化的发展策略制定提供依据。