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961.
为了保障地铁安全运营,提高突发事件发生后人员疏散的效率,基于实际地铁站的尺寸和载客量,利用Pathfinder软件对北京市某特殊地铁站进行建模;结合站点内不同时间段的人流特征,分析站点内可能存在的不利工况,并对各类工况进行仿真模拟。结果表明:地铁站点内疏散的瓶颈区域为站台和站厅连接处的楼梯口;早高峰时期列车满员时,候车人数超过200需要采取限流措施;晚高峰时期列车人数在1 056左右时,候车人数超过576需增加引导人员限制人员流动。研究成果可为特殊地铁站点的疏散通道设计和日常的人流安全管理提供理论依据。 相似文献
962.
本文对20Hz-40GHz电磁环境自动监测系统进行了说明,对系统各个硬件组成部分分别进行了介绍,并详尽阐述了如何通过软件控制完成自动监测功能。最后对监测点的选择方法进行了分析。 相似文献
963.
构建湿地堵塞问题的研究 总被引:19,自引:3,他引:16
研究了复合垂直流构建湿地(IVCW)中与填料堵塞相关的填料粒径、渗透性能、有机质含量等因素的变化.经过颗粒分析得知填料粒径在2~5mm间,运用自制的砂样管对填料进行原位采样,渗透试验结果表明IVCW填料层的渗透系数随填料深度的增加而增加.IVCW填料各层中,渗透系数最小值存在于表层以下15~30cm处.IVCW系统运行52个月后,仅填料表面至15cm深处有少量有机质存在,15cm深度以下有机质含量极少,表明IVCW系统运行稳定,未出现堵塞现象.文中通过分析填料堵塞的影响因素提出相应的预防措施和对策. 相似文献
964.
高级综合稳定塘处理养猪场废水 总被引:5,自引:0,他引:5
针对大型规模化养猪场污水污染负荷高 ,行业利润水平低的特点 ,采用高级综合稳定塘工艺对广州市某养猪场的废水进行处理。实际运行结果表明 ,在废水CODCr为 1 5 899mg L、BOD5为 1 0 84 0mg L、氨氮为 1 2 83mg L和SS为30 2 4mg L的条件下 ,出水CODCr为 71 5mg L、BOD5为 2 3mg L、氨氮为 6 6 5mg L ,SS为 34mg L ,达到畜禽养殖业污染物排放标准 (GB1 85 96 2 0 0 1 )的要求 相似文献
965.
966.
基于GIS的湖泊区域地表水环境影响评价方法 总被引:6,自引:0,他引:6
对地理信息系统(Geographic Information System,GIS)技术在地表水环境影响评价中的应用进行了系统分析,指出了应用GIS的技术优势。通过实例研究,提出了基于GIS的区域地表水环境影响评价的方法步骤。在环境监测数据的基础上,利用计算机软件ArcView对BOD5和COD两个评价参数的监测值在水域中的空间分布进行分析,绘制区域等值线,结合地表水评价标准,进行水质评价,确定不同等级水质的空间分布区域。最后对应用GIS应注意的问题进行了分析。 相似文献
967.
Ebis is the intelligent environmental biotechnological informatics software developed for judging the effectiveness of the microorganism strain in the industrial wastewater treatment system(IWTS) at the optimal status. The parameter, as the objective function for the judgment, is the minimum reactor volume ( Vmin ) calculated by Ebis for microorganism required in wastewater treatment. The rationality and the universality of Ebis were demonstrated in the domestic sewage treatment system(DSTS) with the data published in US Aand China at first, then Fhhh strain‘s potential for treating the purified terephthalic acid(PTA) was proved. It suggests that Ebis would be useful and universal for predicating the technique effectiveness in both DSTS and IWTS. 相似文献
968.
The central objectives of the European Forum on Integrated Environmental Assessment (EFIEA) include improving the scientific
quality of Integrated Environmental Assessments (IEA) as well as strengthening the interactions between science and policy
making in environmental matters. This paper is intended to provide a concise assessment of the evolution of IEA methods and
present it as a background to current thinking on and practice in IEA. Historical roots of IEA concepts and applications are
explored. Common elements and distinctive features in recent proposals to define IEA are sorted and a liberal definition is
proposed for the purposes of the present methodological study. This definition emphasizes the interdisciplinary character
and environmental policy orientation of IEAs. Changes in the nature, social perception, and management of environmental problems
are identified as the major factors driving methodological development in IEAs. A simple scheme is proposed to arrange the
main elements of IEA: disciplinary tools, integration tools, and assessment frameworks. The role of IEAs in environmental
management is examined by adopting the concept of risk management functions. Due to the varying needs for interdisciplinary
research and diverging degrees of policy involvement across those functions, the potential contribution of IEAs to activities
belonging to different functions also varies. The flexibility and diversity of IEAs are demonstrated by a sampler of frameworks
that have been developed to address profoundly different problems and audiences.
This revised version was published online in July 2006 with corrections to the Cover Date.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
969.
采用基于模糊数学的综合二级评判方法评价大连10条城市道路交通环境噪声污染程度。结果表明,受交通噪声冲击影响最大的是西安路大连商业城居民小区路段,影响最小的是如意街大连商业城居民小区路段,与实际调查结果基本一致,体现了该评价方法的合理性和科学性。 相似文献
970.
Future habitat loss and extinctions driven by land‐use change in biodiversity hotspots under four scenarios of climate‐change mitigation
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Brian Barker Thomas M. Brooks Louise P. Chini Qiongyu Huang Rachel M. Moore Jacob Noel George C. Hurtt 《Conservation biology》2015,29(4):1122-1131
Numerous species have been pushed into extinction as an increasing portion of Earth's land surface has been appropriated for human enterprise. In the future, global biodiversity will be affected by both climate change and land‐use change, the latter of which is currently the primary driver of species extinctions. How societies address climate change will critically affect biodiversity because climate‐change mitigation policies will reduce direct climate‐change impacts; however, these policies will influence land‐use decisions, which could have negative impacts on habitat for a substantial number of species. We assessed the potential impact future climate policy could have on the loss of habitable area in biodiversity hotspots due to associated land‐use changes. We estimated past extinctions from historical land‐use changes (1500–2005) based on the global gridded land‐use data used for the Intergovernmental Panel on Climate Change Fifth Assessment Report and habitat extent and species data for each hotspot. We then estimated potential extinctions due to future land‐use changes under alternative climate‐change scenarios (2005–2100). Future land‐use changes are projected to reduce natural vegetative cover by 26‐58% in the hotspots. As a consequence, the number of additional species extinctions, relative to those already incurred between 1500 and 2005, due to land‐use change by 2100 across all hotspots ranged from about 220 to 21000 (0.2% to 16%), depending on the climate‐change mitigation scenario and biological factors such as the slope of the species–area relationship and the contribution of wood harvest to extinctions. These estimates of potential future extinctions were driven by land‐use change only and likely would have been higher if the direct effects of climate change had been considered. Future extinctions could potentially be reduced by incorporating habitat preservation into scenario development to reduce projected future land‐use changes in hotspots or by lessening the impact of future land‐use activities on biodiversity within hotspots. 相似文献