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421.
Subas P. Dhakal 《Disasters》2018,42(2):294-313
South Asia is one of the regions of the world most vulnerable to natural disasters. Although news media analyses of disasters have been conducted frequently in various settings globally, there is little research on populous South Asia. This paper begins to fill this gap by evaluating local and foreign news media coverage of the earthquake in Nepal on 25 April 2015. It broadens the examination of news media coverage of disaster response beyond traditional framing theory, utilising community capitals (built, cultural, financial, human, natural, political, and social) lens to perform a thematic content analysis of 405 news items. Overall, financial and natural capital received the most and the least emphasis respectively. Statistically significant differences between local and foreign news media were detected vis‐à‐vis built, financial, and political capital. The paper concludes with a discussion of the social utility of news media analysis using the community capitals framework to inform disaster resilience.  相似文献   
422.
采用高温加热法制备了涂铁石英砂和无烟煤联用的双层改性滤料,并通过过滤试验对比验证了其对矿井水中不同污染物的去除效果。过滤6 h出水浊度为0.3 NTU,ρ(COD)降为2.5 mg/L,均低于饮用水标准限值,Fe、Mn的去除率分别达88.7%和66.7%,并通过反冲洗试验,确定了该滤料的反冲洗强度q=16 L/(m2.s)和过滤周期T=370 min。滤后水质可满足淡化除盐进水要求,具有广阔的应用前景。  相似文献   
423.
The estimation of humidity in the unsaturated zone of soils and NAPL saturation in contaminated aquifers may be based on the interpretation of electrical resistivity index logs. In the present work, concepts of the theory of the two-phase flow in pore networks are employed to interpret the form of the equilibrium and dynamic resistivity index curves of large porous samples. A resistivity cell is constructed to measure the capillary and electrical properties of large samples of unconsolidated porous media. The drainage capillary pressure and resistivity index curves of a sand column are measured by using the micropore membrane (porous plate) method, where a 0.5% wt/vol NaCl aqueous solution is displaced by n-dodecane. The dynamic resistivity index curves are measured by using the continuous injection technique for various orientations of the sand column. Based on concepts of the two-phase flow theory, concerning the dominant displacement growth pattern in a pore network and arising from the cooperative effects of capillary, buoyancy, and viscous forces, approximate relationships are developed for the resistivity index and saturation exponent as functions of the water saturation. The saturation exponent decreases as the displacement advances and the fluid distribution across the sand column tends to be homogenized after oil breakthrough. Both the resistivity index and saturation exponent increase as the displacement pattern tends to become compact and stable. In the destabilized flow pattern, as the Bond number decreases, the resistivity index may increase respectably within a narrow range of values of the Bond number. This happens when the thickness of the unstable capillary finger exceeds the lateral dimension of the porous sample and becomes a fractal percolation cluster. The saturation exponent becomes almost constant and independent of water saturation only over the destabilized displacement pattern at high values of the Bond number.  相似文献   
424.
The background of this work is the international decision process with regard to the selection of chemicals to be assessed with priority. In order to stress the precautionary principle, mass flows were analysed rather than concentrations, threshold values, etc., as preferred by the chemical legislation (which still excludes the marine area). Lindane, hexachlorobenzene (HCB), trichloroacetic acid and its sodium salt, medium-chained chlorinated paraffins and tributyltin (TBT) were selected due to their great relevance for the marine area. Trichloroacetic acid is an interesting model compound on account of its accidental formation by degradation of volatile chlorinated hydrocarbons and during chlorination processes. In addition, a hypothetical compound was modelled, representing a highly water-soluble substance with low vapour pressure. The balancing area is the Baltic Sea and its catchment area. In order to model the substance flows, the 'Input/Output-load model' has been developed. The model quantifies the shift and the distribution of a yearly load of the substance investigated from the terrestrial-limnic into the marine compartment (Baltic Sea). Water-soluble substances, which are usually considered to be of no concern, may enter the sea in great amounts and, if not degradable, remain there. It turned out to be necessary to take into account remobilisation, unintended formation and point as well as line-sources.  相似文献   
425.
把信息化技术用于油气田安全领域,用采集的现场数据评估安全生产环境,实现油气田安全信息化是近年来的新课题。为了有效地监测和预防油三高气田(高含硫、高产量、高压力)井喷事故造成的灾害,讨论了基于网络架构的重大事故现场监测数据采集管理系统软件的研究与设计,包括气象数据,传感器数据,监测设备GPS数据与视频信息的实时采集、处理、分析与显示,并且分段说明了该系统各部分的设计和实现的重点.该系统具有友好的人机界面,并且引入了流媒体技术、无线传感器技术等多种先进技术,能够最大程度地得到全面的表征油气田安全的数据与信息;该系统已经在研究实例龙岗油气田的实验中证明了具有安全生产方面的现实意义。  相似文献   
426.
Biologically active carbon (BAC) system was set up in a water plant of South China during January to December 2007,to study the invertebrate community characteristics of BAC filter.Thirty-seven invertebrate species were found,of which 28 belonging to rotifers.Filter operation could lead to an output of invertebrates in high abundances with the filtrate,and the maximum density could reach 5608 individuals/m 3.Average abundances in the effluent water increased in 27-33 folds in comparison to the influent water during the sampling period.Invertebrate community succession had the following trend:filter-feeding animals → small benthic invertebrates → large benthic and resistant invertebrates.Abundances of large-sized invertebrates (copepod adult and oligochaete) at bigger-media column were significantly higher than that at small-media column.The results implied the abundant species diversity of invertebrate in BAC filter.The relationship between invertebrate and biofilm still remain to be studied in detail.  相似文献   
427.
卢勇  徐治国  赵杰 《环境科技》2009,22(5):32-34
DASB反应器作为新型现代厌氧反应器,具有结构简单、运行方便,处理效果好等优点,在处理生活污水方面有着广泛的应用前景。研究了常温条件下,DASB处理生活污水的启动运行,得出在最佳水力停留时间6h时,COD和SS的平均去除率分别达到81.48%和86.07%。  相似文献   
428.
毛细压力法对水处理滤料亲油亲水比的研究   总被引:2,自引:0,他引:2  
基于Washburn方程,定义了滤料的亲油亲水比(LHR),利用毛细压力法测定了果壳、锰砂、陶粒、石英砂和瓷砂的润湿速率,计算了LHR值,并对滤料的表面微观结构进行了研究.实验表明,直线拟合程度较好,结果重现性较高.实验方法可行.数据可靠.其中果壳的LHR值最大,达到66.87,表现出了最强的亲油性,其次是锰砂、陶粒、石英砂,三者的亲油性略好于瓷砂,其LHR值分别为1.24、1.22、1.16和0.80,与XPS和FTIR分析结果一致,证实了滤料LHR值的差异主要取决于滤料表面微观结构的不同.  相似文献   
429.
利用三维荧光光谱-平行因子分析(EEM-PARAFAC)手段结合吸收光谱分析,研究了小球藻指数期和稳定期培养液中溶解有机物(DOM)在秋季天然太阳辐射作用下的光降解动力学特征.结果表明,小球藻生长过程中除能产生短波激发类腐殖质组分C1(其荧光峰的激发/发射波长位置为240,335 nm /406 nm)及类蛋白质组分C3(225,275 nm/334 nm)外,还会形成长波激发类腐殖质组分C2(260,395 nm /502 nm),表明C2组分并非仅有传统认为的陆源属性,同时也具有自生源属性.稳定期培养液的吸收光谱在250~300 nm范围内出现的肩峰,可用于指示水环境中现场自生源的贡献.不同生长时期培养液中DOM的吸收系数和荧光组分的降解动力学都符合一级反应方程.稳定期类腐殖质荧光组分(C1和C2)的光降解程度略高于指数期,但指数期类色氨酸组分(C3)的光降解程度略高于稳定期.经太阳辐照6 d后,小球藻培养液的吸收系数a350及各荧光组分的平均损失率分别达到83.0%、84.0%、64.8%和80.0%,对应的半衰期只有1.6~5.0 d,揭示出藻类自生来源的DOM具有很强的光化学降解活性.  相似文献   
430.
道路绿化带对街道峡谷内污染物扩散的影响研究   总被引:1,自引:0,他引:1  
徐伟嘉  幸鸿  余志 《环境科学》2012,33(2):532-538
研究了道路绿化带对街道峡谷内流场与机动车尾气扩散的影响特征.假设绿化带树冠为均匀多孔介质,采用压力损失系数表征树冠对空气流动的阻碍作用,建立可用于数值模拟的绿化带多孔介质物理模型.采用稳态k-ε湍流模型结合组分输运方程模拟道路中央有绿化带街道峡谷内的尾气扩散过程,模拟结果与风洞试验数据对比吻合较好.分析发现,有绿化带街道峡谷内存在一个围绕树冠的顺时针旋涡,旋涡中心略偏向右上方,背风面污染物浓度显著增大,较无绿化带的污染物平均浓度增长46.0%.进一步模拟了不同绿化带树冠高度情况下街道峡谷内流场与浓度场,发现随着树冠位置的上升,峡谷内流场旋涡中心逐步上移且偏向迎风建筑物,峡谷内整体气流速度下降,污染物浓度逐步升高,树冠底部高度为8 m时其污染物浓度可达4 m时的2倍多;尤其是当树冠顶部超过屋顶高度时,峡谷内污染物总体浓度增长迅速.  相似文献   
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