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671.
基于AHP的高处坠落事故脆性分析 总被引:4,自引:2,他引:2
高危建筑行业施工作业中高处坠落事故居于“五大伤害”事故之首。以高处坠落事故的发生为研究对象,由层次分析法得出导致事故发生的各因素的相对重要度的排序向量,根据复杂系统的脆性理论,通过脆性激发度的定义,对高处坠落事故进行了脆性分析。结果表明,使用不安全设施、无防护措施、强度不够和处于不安全位置这四种因素是导致高处坠落事故发生的主要脆性源。研究结果为建筑行业事故防控体系的建立提供一种新的途径和思路。 相似文献
672.
Daniel B. Wright James A. Smith Gabriele Villarini Mary Lynn Baeck 《Journal of the American Water Resources Association》2014,50(3):713-734
Accurate records of high‐resolution rainfall fields are essential in urban hydrology, and are lacking in many areas. We develop a high‐resolution (15 min, 1 km2) radar rainfall data set for Charlotte, North Carolina during the 2001‐2010 period using the Hydro‐NEXRAD system with radar reflectivity from the National Weather Service Weather Surveillance Radar 1988 Doppler weather radar located in Greer, South Carolina. A dense network of 71 rain gages is used for estimating and correcting radar rainfall biases. Radar rainfall estimates with daily mean field bias (MFB) correction accurately capture the spatial and temporal structure of extreme rainfall, but bias correction at finer timescales can improve cold‐season and tropical cyclone rainfall estimates. Approximately 25 rain gages are sufficient to estimate daily MFB over an area of at least 2,500 km2, suggesting that robust bias correction is feasible in many urban areas. Conditional (rain‐rate dependent) bias can be removed, but at the expense of other performance criteria such as mean square error. Hydro‐NEXRAD radar rainfall estimates are also compared with the coarser resolution (hourly, 16 km2) Stage IV operational rainfall product. Stage IV is adequate for flood water balance studies but is insufficient for applications such as urban flood modeling, in which the temporal and spatial scales of relevant hydrologic processes are short. We recommend the increased use of high‐resolution radar rainfall fields in urban hydrology. 相似文献
673.
Devils lake emergency outlet diversion conflict 总被引:1,自引:0,他引:1
The Devils Lake Emergency Outlet Diversion conflict is systematically studied from a strategic viewpoint using the Graph Model for Conflict Resolution in order to obtain insights about the resolution of this nagging international dispute. By modelling the conflict for the situation existing as of July 2005, just before the project began operation, the dispute is put into proper perspective and, subsequently, a stability analysis is carried out to obtain potential resolutions or equilibria. The results of a sensitivity analysis accurately predict the deal which actually took place when Canada and the American state of North Dakota reached a negotiated settlement. Finally, suggestions are put forward for improving the Boundary Waters Treaty of 1909 between Canada and the United States. 相似文献
674.
Pilar Swart Jo Dewulf Herman Van Langenhove Koen Moonens Kristof Dessein Carl Quaeyhaegens 《Resources, Conservation and Recycling》2011,55(12):1119-1128
The overall resource requirements for the production of germanium wafers for III–V multi-junction solar cells applied in concentrator photovoltaics have been assessed based on up to date process information. By employing the cumulative energy demand (CED) method and the cumulative exergy extraction from the natural environment (CEENE) method the following resources have been included in the assessment: fossil resources, nuclear resources, renewable resources, land resources, atmospheric resources, metal resources, mineral resources and water resources. The CED has been determined as 216 MJ and the CEENE has been determined as 258 MJex. In addition partial energy and exergy payback times have been calculated for the base case, which entails the installation of the high concentration photovoltaics (HCPVs) in the Southwestern USA, resulting in payback times of around 4 days for the germanium wafer production. Due to applying concentration technology the germanium wafer accounts for only 3% of the overall resource consumption of an HCPV system. A scenario analysis on the electricity input to the wafer production and on the country of installation of the HCPV has been performed, showing the importance of these factors on the cumulative resource consumption of the wafer production and the partial payback times. 相似文献
675.
高梯度磁分离技术在水处理中的应用及发展 总被引:1,自引:0,他引:1
高梯度磁分离技术是一种新型的水处理技术,目前已经得到了大量应用,具有广阔的应用前景。本文介绍了它的基本原理,综述了该技术在水处理中的应用现状,并做出了展望。 相似文献
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High speed machining (HSM) of tool steels in their hardened state is emerging as an attractive approach for the mold and die industry due to its potential for significant cost savings and productivity improvement. An experimental study was conducted to investigate the tool wear mechanism and surface integrity in high speed ball nose end milling of hardened AISI A2 tool steel using coated tungsten carbide and polycrystalline cubic boron nitride (PCBN) tools. It is found that coated carbide tools can only be used at low speed (120 m/min) while high content PCBN tools are suitable for HSM range (470 m/min). PCBN tools produce a damage free workpiece with better surface finish and less work hardening. Despite the higher tool cost, HSM with PCBN tools lead to reduction in both total cost and production time per part. 相似文献
679.
空气和煤气吹脱法处理高氨氮废水的对比研究 总被引:1,自引:0,他引:1
研究了在实验室使用空气吹脱法去除高浓度氨氮废水的条件,通过正交实验得出其影响因素大小顺序为:废水pH>气液比r>废水温度tw>表面活性剂浓度c,最佳吹脱条件为pH=11.0,r=550,c=10mg/L,tw=75℃,最高氨氮去除效率达到71.4%。在某焦化厂以终冷塔后焦炉煤气为解吸介质,现场试验影响因素大小顺序为:o废水pH>废水温度tw>气液比r>煤气温度tg>表面活性剂浓度c,最佳吹脱条件为pH=11.5,tw=90℃,r=650,tg=55℃,c=20mg/L。为煤气吹脱解吸回收氨工艺的应用提出了建议。 相似文献
680.
基于高分数据的村级地块面向对象分类方法研究 总被引:1,自引:0,他引:1
针对农作物对地抽样调查工作中村级抽样单元野外调查工作量大的问题,研究了一种基于高分数据的村级农作物种植面积提取方法。以辽宁省北镇市孟家村SPOT5遥感影像为实验数据(主要包括农田、裸地、道路、大棚、水体、房屋等类型),基于eCognition平台,根据局部方差法筛选地物最优分割尺度,按照最优分割尺度从大到小组织实验区地物分割次序,结合影像对象的光谱、形状等特征,建立分类规则,完成了村级农作物种植面积的提取。该方法有效避免了在影像分割时参数反复试错带来的复杂性和随机性,提高了农作物种植面积面向对象分类精度和效率。通过野外调查样地进行精度验证表明,精度达到90.4%,为提高农作物种植面积对地抽样调查工作效率,减少野外调查的工作量提供技术支撑。 相似文献