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61.
混凝土,砂浆和灰砂砖在模拟酸雨条件下的化学行为   总被引:4,自引:0,他引:4  
用周期浸泡加速腐蚀试验法研究pH=3.5、5.6和pH为1.0时SO2-为0、0.06、0.1、0.2mol/L等6种模拟酸雨条件下混凝土、砂浆和灰砂砖的化学行为。研究表明:酸雨对材料的影响,主要是H+侵蚀引起的溶解腐蚀和SO42-侵蚀引起的膨胀腐蚀。  相似文献   
62.
When the explosion of condensed materials occurs in square or circular cross-section tunnel, the subsequent blast wave reveals two patterns: three-dimensional close to the explosive charge and one-dimensional far from the explosion. Pressure decays for these two patterns have been thoroughly studied. However, when the explosion occurs in rectangular cross-section tunnel, which is the most regular geometry for underground networks, the blast wave exhibits a third, two-dimensional, patterns. In order to assess the range of these three patterns, several numerical simulation of blast waves were carried out varying the width and the height of the rectangular cross-section as well as the mass of the charge. Laws are presented to localize the transition zones between the 3D and the 2D patterns, and between the 2D and the 1D patterns, as functions of non-dimensional width and height. The numerical results of the overpressure are compared to existing 3D and 1D laws. An overpressure decay law is proposed to represent the 2D pattern. Knowing the two transition zones and the overpressure decays within these zones, an algorithm is presented to efficiently predict an overpressure map. This algorithm is validated by comparison with experimental data.  相似文献   
63.
It is known that fugitive dust can cause human health and environmental problems, alone or in combination with other air pollutants. These problems are referred to as ‘external costs’ that have been traditionally ignored. However, there is a growing interest towards quantifying externalities to assist policy and decision-making. With this in mind, the present study aimed at discussing the environmental regulations that deal with fugitive dust, the impact of fugitive dust on human health and global climate system, and the available methods for calculating fugitive dust externalities. The damage cost associated with human health and global environmental problems was predicted based on the environmental strategy priority model. The damage cost estimated by the model ranged from 40 to 374 EUR/kg of emitted fugitive dust with a mean value of 120 EUR/kg of emitted fugitive dust. It was also found that PM2.5 and PM10 have contributed to about 60% and 36% of the estimated damage cost, respectively. The remaining 4% was attributed to both nitrate and sulfate aerosols.  相似文献   
64.
国内环境污染损害评估工作刚刚起步,科学评估环境污染损害数额成为亟需解决的问题。在分析国内环境污染损害赔偿现状的基础上,简述了开展污染损害评估的必要性。结合具体案例阐述了环境污染损害评估的计算方法,提出开展环境污染损害评估工作的建议及措施,包括建立高效的环境污染应急处置机制,开展预防为主的企业清洁生产审核验收和企业环境风险评价,建立终身责任追究、产权责任追究和连带责任追究制度等。  相似文献   
65.
《Environmental Forensics》2013,14(3-4):303-321
In the last decade, PETROBRAS has experienced some significant oil spills cases and the PETROBRAS Research Center has played an important role in the company emergency response program by characterizing the spilled oil, monitoring the affected ecosystem, determining the fate of the oil in the environment, and, subsequently, helping the company in assessing the environmental damage. This paper presents the use of advanced chemical analytical techniques (GC/FID, P&T/GC/PID and GC/MS) in some Brazilian oil spill studies in order to determine fractions and individual petroleum hydrocarbons in different matrices such as water, groundwater, sediment, sand, fish and the spilled oil itself. The spill studies encompassed crude and fuel oil releases on land and coastal ecosystems, related to the incidents in Guanabara Bay (Rio de Janeiro), Barigui and Iguassu Rivers (Parana) and Sao Sebastiao Channel (Sao Paulo). Total petroleum hydrocarbons (TPH), n -alkanes, isoprenoids, unresolved complex mixtures (UCM), volatile monoaromatic compounds--benzene, toluene, ethylbenzene and xylenes (BTEX), parent and alkylated homologues polycyclic aromatic hydrocarbons (PAH), and terpanes and steranes were characterized for determining correlation to the spilled oil and other known oil sources and environmental assessment. Some of the acute ecotoxicity data for water and sediment samples is also presented.  相似文献   
66.
地下结构震害类型及机理研究   总被引:24,自引:1,他引:24  
地下结构由于受到周围岩体或土体的约束 ,一直被认为具有良好的抗震性能。但是 ,随着地下结构数量的增多和地下结构震害的频繁出现 ,地下结构的震害问题日益受到世界各国地震工作者的高度重视 ,笔者通过对大量地下结构震害的分析研究 ,对地下结构震害进行了分类 ,并研究了震害的影响因素及机理 ,以期为地下结构的抗震设计提供科学依据和有益的参考。  相似文献   
67.
FAE威力评价方法与目标防护分析   总被引:5,自引:0,他引:5  
对燃料空气炸药(FAE)爆炸场特性进行了分析;从冲击波超压- 冲量毁伤准则出发,提出一种以靶板毁伤效应为评价依据的FAE威力评价方法,并结合易损性等效原理,对不同毁伤等级下目标防护问题进行了分析  相似文献   
68.
探讨了现存建筑物可靠性评价的极限状态方法,提出荷载水平方法,建立了结构构件可靠性评价的极限状态准则。基于结构失效的机构理论,提出结构体系可靠性评价的“破损机构”方法,以使结构成为“破损机构”或“局部破损机构”的“破损截面”的最高等级作为结构体系可靠性评级。  相似文献   
69.
房屋建筑的震害矩阵计算与设防投资比确定   总被引:10,自引:0,他引:10  
本文包括两个内容:1研究了现有建筑的设防延伸率,给出了用设防延伸率计算震害矩阵的分析方法,并用框架、厂房的计算破坏比与包头西地震调查得到的破坏比进行了比较,二者基本吻合;2.通过咨询抗震设计专家,确定并给出了框架、砖结构、厂房的设防投资比。  相似文献   
70.
邓民宪 《灾害学》1998,13(2):22-27
根据多次历史地震埋地管道震害调查资料的统计和定性分析,应用灰色系统理论,以管道震害率作为参考数列,以地震烈度、场地类型、管道材料、接口构造和管径尺寸作为比较数列,对埋地管道震害率进行了多因素灰色关联分析,排出了关联序.研究结果客观地揭示出震害率与各影响因素之间的相互关系,为进一步研究理地管道的震害预测方法提供了科学依据.  相似文献   
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