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641.
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出租车排放是城市大气污染的重要来源,对高排放出租车加严管理是改善空气质量的有效手段之一.在北京市选取6辆有代表性的高里程汽油出租车,较全面地评估了维护保养、更换三元催化器对出租车油耗和排放的影响,以及三元催化器在更换后的老化情况.研究表明:常规的维护保养可显著改善车辆的燃油经济性,保养后车辆的100 km油耗比原车降低了2%~4%,但对THC和NOx排放的影响很小.原车排放越高,更换三元催化器的减排效果越显著,且更换第一级三元催化器(前三元催化器)和同时更换第一、二级三元催化器(前、后三元催化器)的减排效果差别较小.更换三元催化器后行驶里程约18.5×104 km时,有4辆出租车对CO、THC和NOx的减排比例仍保持在45%、26%和29%的平均水平,说明更换三元催化器后,在约20×104km的行驶里程内对气态污染物能保持较好的减排效果. 相似文献
643.
基于复杂系统理论的天津市环境与经济关系分析 总被引:1,自引:0,他引:1
基于区域环境与经济系统开放复杂性特点,利用最大流原理建立区域环境与经济复杂系统模型分析二者间的关系. 以天津市为研究对象,研究了其环境与经济系统在2001—2010年的发展过程,借助Matlab R2010a求ξ(系统稳定性系数),通过ξ的变化规律分析各组元间的相互作用和系统的整体发展状况. 结果表明:2001—2010年天津市环境与经济系统中各组元间的相互作用逐年增强,ξ逐年上升并在2010年达到最大值(18.615 4),表明该系统中环境与经济各组元间的相互作用逐渐协调,天津市的环境与经济发展呈相互促进的关系. 相似文献
644.
Richard N. Mutafela Marcia Marques Yahya Jani Mait Kriipsalu William Hogland 《Chemistry and Ecology》2013,29(9):877-890
Physico-chemical characteristics of waste, particularly fine fraction (FF), from an old crystal glass waste dump in Sweden were studied to assess recycling or disposal alternatives. Hand-sorting of the waste indicated glass content of 44.1% while sieving established the FF as a more soil-like mix of glass and other materials constituting 33.3% of all excavated waste. The FF was around neutral pH with 24.4% moisture content, low values of Total Dissolved Solids, Dissolved Organic Carbon and fluorides, but hazardous concentrations of As, Cd, Pb and Zn according to the Swedish Environmental Protection Agency guidelines. While the FF leached metals in low concentrations at neutral pH, it leached considerably during digestion with nitric acid, implying leaching risks at low pH. Thus, the waste requires safe storage in hazardous waste class ‘bank account’ storage cells to avoid environmental contamination as metal recovery and other recycling strategies for the glass waste are being developed. The study could fill the information gap regarding preservation of potential resources in the on-going, fast-paced excavation and re-landfilling of heavy metal contaminated materials in the region. 相似文献
645.
《Environmental Hazards》2013,12(1):31-35
Abstract This paper explores the failure of historians to properly engage the study of natural hazards. It argues that by focusing mainly on individual calamities, historians have overlooked the larger social and economic forces that have shaped the response to natural disaster over the last century. Two important trends, real estate capitalism and the entry of the state into the political economy of hazards after World War II, are singled out as crucial for understanding US society's response to natural disaster. As a result of these historical forces, risk became a commodity, with harmful environmental consequences. 相似文献
646.
Michael Bruce BECK Rodrigo VILLARROEL WALKER 《Frontiers of Environmental Science & Engineering》2013,7(5):626-639
The role of water security in sustainable development and in the nexus of water, food, energy and climate interactions is examined from the starting point of the definition of water security offered by Grey and Sadoff. Much about the notion of security has to do with the presumption of scarcity in the resources required to meet human needs. The treatment of scarcity in mainstream economics is in turn examined, therefore, in relation to how each of us as individuals reconciles means with ends, a procedure at the core of the idea of sustainable development. According to the Grey-Sadoff definition, attaining water security amounts to achieving basic, single-sector water development as a precursor of more general, self-sustaining, multi-sectoral development. This is consistent with the way in which water is treated as “first among equals”, i.e. privileged, in thinking about what is key in achieving security around the nexus of water, food, energy and climate. Cities, of course, are locations where demands for these multiple resource-energy flows are increasingly being generated. The paper discusses two important facets of security, i.e., diversity of access to resources and services (such as sanitation) and resilience in the behavior of coupled human-built-natural systems. Eight quasi-operational principles, by which to gauge nexus security with respect to city buildings and infrastructure, are developed. 相似文献
647.
Experience sampling methodology and daily diary (ESM/DD) research elicits repeated reports of immediate or very recent experiences from the same sample of people for several days or weeks. Experience sampling and diary methods were almost unheard of in organizational research 15 years ago, but the past decade has seen a rapid rise in their use. These methods are helpful in studying dynamic within‐person processes involving affect, behavior, interpersonal interactions, work events, and other transient workplace phenomena over time. Assessing cross‐level effects of traits or other stable features on within‐person processes and reactivity is also possible with ESM/DD data. We provide an introduction to issues in designing and carrying out an ESM/DD study, including data collection choices and schedules, measures, technology, training and motivation of participants, and analysis of multilevel data. We offer best practice recommendations and refer readers to further resources for additional detail on conducting and analyzing ESM/DD research. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
648.
构筑可持续发展的循环型社会体系 总被引:2,自引:0,他引:2
可持续发展社会的形成并不仅指单纯的物质循环,而是用生态学原理来调和社会和经济的发展,使社会·经济·环境都达成持续的生态平衡。通过论述日本循环型社会形成基本法等相关法律体系,分析了面向循环型经济社会建设的产业体系的发展方向,通过区域性循环社会的实践阐述了从循环型经济社会向可持续发展社会转变的重要意义。 相似文献
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650.
循环经济发展的宏观形势下,企业的竞争环境发生了转变,经营者在运作过程中不能只考虑经济绩效,同时还必须环境绩效和社会绩效的影响,因此企业环境会计的账户设置也应当进行适当的调整;但是目前关于这方面的理论研究尚显得较为单薄.该文首先从理论推演方面探讨和归纳出了循环经济背景下企业日常经营运作机制的相关评价指标;然后分别选择了制造型企业和生产型服务企业各一家作为研究样本,运用多元统计学中的逻辑回归分析法作为工具进行了实证研究;并结合实证分析的结果,确定了循环经济背景下这两类企业环境会计账户设置优化的可行性途径. 相似文献