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601.
As part of the European Tracer Experiment (ETEX) two successful atmospheric experiments were carried out in October and November, 1994. Perfluorocarbon (PFC) tracers were released into the atmosphere in Monterfil, Brittany, and air samples were taken at 168 stations in 17 European countries for 72 h after the release. Upper air tracer measurements were made from three aircraft. During the first experiment a westerly air flow transported the tracer plume north-eastwards across Europe. During the second release the flow was eastwards. The results from the ground sampling network allowed the determination of the cloud evolution as far as Sweden, Poland and Bulgaria. This demonstrated that the PFT technique can be successfully applied in long-range tracer experiments up to 2000 km. Typical background concentrations of the tracer used are around 5–7 fl ?-1 in ambient air. Concentrations in the plume ranged from 10 to above 200 fl/?-1. The tracer release characteristics, the tracer concentrations at the ground and in upper air, the routine and additional meteorological observations at the ground level and in upper air, trajectories derived from constant-level balloons and the meteorological input fields for long-range transport models are assembled in the ETEX database. The ETEX database is accessible via the Internet. Here, an overview is given of the design of the experiment, the methods used and the data obtained. 相似文献
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In recent years, serious fire and explosion accident in petrochemical storage tanks have taken place frequently. Therefore, increasing the firefighting force in petrochemical parks is particularly important. The ambition of the paper is mainly studying the supply intensity of Aqueous Film Forming Foam (AFFF) extinguishing agent. Fire extinguishing agent demand calculation method that can be capable of matching fire scale is established by carrying out series of fire extinguishing experiments. 6% AFFF is chosen to carry out three groups of experiments respectively: fire extinguishing agent fluidity determination, series groups of small size simulation oil pool fire and 177 square meters of large oil pool fire extinguishing experiment. The situation of fire extinguishing on fuel surface of AFFF can be explored through experimental means under cold and hot conditions. The data obtained from experiments prove a higher conformity between covering process and covering model under the cold condition. The model can predict the cold coverage of AFFF effectively. After unifying the supply flow from each experiment, the statistics can be fitted and come to the minimum supply intensity algorithm of AFFF against the target storage tank specifications. The algorithm is used to estimate the minimum supply intensity when extinguishing full liquid surface fire. This model also can be used as reference for petrochemical fire protection. 相似文献
605.
为探究平行换乘车站火灾烟气扩散特性及排烟优化模式,利用1∶10地铁换乘车站模型,在公共站厅、站台、单洞单线隧道、单洞双线隧道中设计多种火灾场景,分析各区域内的顶棚温度分布情况。结果表明:公共站厅不同位置发生火灾时,各区域内的烟气蔓延特性和通风排烟效果不同;站台火灾时,打开屏蔽门能增大补风量,延缓火源上方的升温过程,降低站台内部温升,并且在联合站台及两侧隧道排烟时仅开启火源附近6个屏蔽门有利于提高排烟效率;单洞单线隧道火灾时烟气温度相对较高,单洞双线隧道火灾时,近火源区域内起火隧道和未起火隧道的烟气分布特性不同,烟气可通过打开的屏蔽门蔓延至临近站台,开启隧道排烟及站台送风后能有效减小温升幅度和烟气扩散范围。实验结果可为平行换乘车站中的火灾烟气通风控制方案提供数据支撑。 相似文献
606.
Yuhua Liang Lauren K. Henderson Kerk F. Kee 《Environmental Communication: A Journal of Nature and Culture》2018,12(4):541-557
In three phases, this study identifies and evaluates the major messages being used in communication campaigns focused on the ongoing drought in California. A literature review in Phase 1 resulted in a typology of 12 message strategies. Following this typology, trained coders in Phase 2 evaluated water conservation messages (N?=?100) to determine whether each message utilized one or multiple strategies. The results revealed various frequencies of strategy application; and a correlational analysis rendered a pattern of strategy use in combinations. Phase 3 focused on a controlled message experiment applying the three most relevant strategies: conservation tips, loss aversion, and evidence of drought. Analysing data sampled from California residents (N?=?180), conservation messages, regardless of the strategy, led to attitude change in a negative direction. Additional analyses revealed interesting patterns of combinatorial strategy effects. The results call for a re-examination of message strategies as they may lead to several unfavourable outcomes. 相似文献
607.
本文围绕以手机为主的电子类生活垃圾回收环节,基于EPR电子生活垃圾回收实验及目前电子类生活垃圾的回收激励政策和效果,运用典型相关分析方法确定激励政策及政策效果的主要影响变量,研究以手机为主的电子类生活垃圾回收的激励政策与政策效果之间的关系,强化电子类生活垃圾回收的政策措施,扩大政策效果,促进资源的回收及再利用。本文设定的回收激励政策包括政府对废旧手机回收率的最低要求、优惠力度以及获得高优惠的最低回收率要求,政策效果包括废旧手机实际回收率、销售市场营业额以及生产者补贴总额等方面。研究结果表明,电子类生活垃圾回收激励政策与政策效果之间存在着显著的相关关系,其中,获得高优惠的最低回收率对废旧手机实际回收率有显著抑制作用,废旧手机回收率的最低要求对销售市场营业额有显著抑制作用。本文在此基础上给出了政策建议。 相似文献
608.
Artti Juutinen Anna-Kaisa Kosenius Ville Ovaskainen Anne Tolvanen Liisa Tyrväinen 《Journal of Environmental Planning and Management》2017,60(3):399-418
The management of forests for multiple benefits, such as recreational services alongside timber production, can greatly benefit from the knowledge of public preferences for management-related forest attributes. This paper investigates citizens’ recreational use and preferences for recreation-oriented management in the case of state-owned commercial forests in Finland using data from a choice experiment study. We focus on attributes related to the typical management practices applied to enhance recreation: scenic buffer zones along waters, game bird habitats, and the quality of scenery along hiking trails. Recreational use and its frequency were found to be related to citizens’ background and specific outdoor activities. The scenic buffer zones were the most important attribute to the citizens. While the recreation-enhancing practices were generally valued, respondent segments with distinct preferences were found. Preference heterogeneity was related to citizens’ socioeconomic characteristics and recreational profiles. 相似文献
609.
电Fenton方法处理六氯苯污染沉积物工艺参数研究 总被引:2,自引:2,他引:0
采用正交试验方法对六氯苯污染的沉积物进行了电Fenton修复研究,分析了各影响因素的显著性水平。在此基础上利用Matlab软件进行了响应曲面和回归分析,探讨了各影响因素分别对HCB的去除率影响程度;确定了电Fenton修复的最佳工作条件:以不锈钢片为电极,处理135gHCB污染沉积物,H2O2(30%V/V)投加量5mL电极间距为6cm,在外加电压13.43V,电解质NaCl投加量5.30g,初始pH值为1.98,经过2h的处理后,六氯苯去除率可达70.9%。 相似文献
610.