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451.
Knowledge of appropriate behaviour during an earthquake is crucial for prevention of injury and loss of life. The Israeli Home Front Command conducts a yearly earthquake education programme in all Israeli schools, using three types of educational interventions: lectures, drills and a combination of the two. The aim of this study was to evaluate the effectiveness of these interventions in providing students with knowledge. We distributed a questionnaire to 2,648 children from the 5th and 6th grades in 120 schools nationwide. Knowledge scores for both 5th and 6th grades were increased, regardless of type of intervention, compared to the non-exposure group. A combined intervention of lectures and drills resulted in the highest knowledge scores. Our findings suggest that for the age group studied a combination of lectures and drills will likely prepare students best for how to behave in the event of an earthquake.  相似文献   
452.
Environmental and Ecological Statistics - A statistical challenge to analyse hyperspectral data is the multicollinearity between spectral bands. Partial least squares (PLS) has been extensively...  相似文献   
453.
Surface O3 production has a highly nonlinear relationship with its precursors. The spatial and temporal heterogeneity of O3-NO x -VOC-sensitivity regimes complicates the control-decision making. In this paper, the indicator method was used to establish the relationship between O3 sensitivity and assessment indicators. Six popular ratios indicating ozone-precursor sensitivity, HCHO/NO y , H2O2/ HNO3, O3/NO y , O3/NO z , O3/HNO3, and H2O2/NO z , were evaluated based on the distribution of NOx- and VOC-sensitive regimes. WRF-Chem was used to study a serious ozone episode in fall over the Pearl River Delta (PRD). It was found that the south-west of the PRD is characterized by a VOCsensitive regime, while its north-east is NO x -sensitive, with a sharp transition area between the two regimes. All indicators produced good representations of the elevated ozone hours in the episode on 6 November 2009, with H2O2/HNO3 being the best indicator. The threshold sensitivity levels for HCHO/NOy, H2O2/HNO3, O3/NO y , O3/NO z , O3/HNO3, and H2O2/NO z were estimated to be 0.41, 0.55, 10.2, 14.0, 19.1, and 0.38, respectively. Threshold intervals for the indicators H2O2/HNO3, O3/NO y , O3/NO z , O3/HNO3, and H2O2/NO z were able to identify more than 95% of VOC- and NO x -sensitive grids. The ozone episode on 16 November 16 2008 was used to independently verify the results, and it was found that only H2O2/HNO3 and H2O2/NO z were able to differentiate the ozone sensitivity regime well. Hence, these two ratios are suggested as the most appropriate indicators for identifying fall ozone sensitivity in the PRD. Since the species used for indicators have seasonal variation, the utility of those indicators for other seasons should be investigated in the future work.
  相似文献   
454.
CRH_1型动车组一等座车厢火源热释放速率研究   总被引:1,自引:0,他引:1  
为了得到不同通风条件和旅客行李条件下CRH1动车组一等座车厢的火源热释放速率的合理取值范围,以CRH1型动车组一等座车厢为研究对象,以锥形量热仪和大型量热仪测定的高速客车车体内材料和行李的燃烧性能为输入参数,运用FDS软件模拟6种火灾场景下车厢的火源热释放速率随时间的变化规律,分析了通风条件、火灾荷载密度、可燃物间距和行李重量对车厢火源热释放速率的影响。研究结果表明:在不考虑旅客行李时,各种通风条件下车厢最大火灾热释放速率在1.86-4.34MW之间;在车门与车窗开启条件下,与不考虑旅客行李的情况比较,人均携带10、20kg行李时,火源热释放速率分别增加了12.84、15.38MW,增加的幅度分别为570%和684%。  相似文献   
455.
The selection of new settlement areas and the construction of safe buildings, as well as rendering built‐up areas safe, are of great importance in mitigating the damage caused by natural disasters. Most cities in Turkey are unprepared for natural hazards. In this paper, Çanakkale, located in a first‐degree seismic zone and sprawled around the Sartçay Delta, is examined in terms of its physical vulnerability to natural hazards. Residential areas are analysed using GIS (geographic information system) and remote‐sensing technologies in relation to selected indicators. Residential areas of the city are divided into zones according to an evaluation of geological characteristics, the built‐up area's features, and urban infrastructure, and four risk zones are determined. The results of the analysis show that the areas of the city suitable for housing are very limited. In addition, the historical centre and the housing areas near Sartçay stream are shown to be most problematic in terms of natural disasters and sustainability.  相似文献   
456.
Tidal vortices play an important role in the flushing of coastal regions. At the mouth of a tidal inlet, the input of circulation by the ebb tide may force the formation of a starting-jet dipole vortex. The continuous ebb jet current also creates a periodic sequence of secondary vortices shed from the inlet mouth. In each case, these tidal vortices have a shallow aspect ratio, with a lateral extent much greater than the water depth. These shallow vortices affect the transport of passive tracers, such as nutrients and sediment from the estuary to the ocean and vice versa. Field observation of tidal vortices primarily relies on ensemble averaging over several vortex events that are repeatable in space and can be sampled by a fixed Eulerian measurement grid. This paper presents an adaptive approach for locating and measuring within tidal vortices that propagate offshore near inlets and advect along variable trajectories set by the wind-driven currents. A field experiment was conducted at Aransas Pass, Texas to measure these large-scale vortices. Locations of the vortices produced during ebb tide were determined using near real-time updates from surface drifters deployed near or within the inlet during ebb tide, and the paths of towed acoustic Doppler current profiler (ADCP) transects were selected by analysis of the drifter observations. This method allowed ADCP transects to be collected within ebb generated tidal vortices, and the paths of the drifters indicated the presence of both the starting-jet dipole and the secondary vortices of the unstable ebb tidal jet. Drifter trajectories were also used to estimate the size of each observed vortex as well as the statistics of relative diffusion offshore of Aransas Pass. The field data confirmed the starting-jet spin-up time (time until the vortex dipole begins to propagate offshore) measured in the laboratory by Bryant et al. [6] and that the Strouhal condition of \(St=0.2\) predicts the shedding of secondary vortices from the inlet mouth. The size of the rotational core of the vortex is also shown to be approximated physically by the inlet width or by \(0.02UT\) , where U is the maximum velocity through the inlet channel and T is the tidal period, and confirms results found in laboratory experiments by Nicolau del Roure et al. [23]. Additionally, the scale of diffusion was approximately 1–15 km and the apparent diffusivity was between 2–130  \(m^2/s\) following Richardsons law.  相似文献   
457.
People frequently have to work in high repetitive jobs. Previous research has focused exclusively on the effects of task repetitiveness on well‐being, while neglecting effects on work performance. In the present study, we aimed to fill this void by conducting two workplace simulations with experimental manipulations of task repetitiveness. Participants worked for about 5 hours at either a computer workstation, compiling computer hardware packages according to customer requests (Experiment 1, N = 160), or at an assembly line, piecing together equipment sets for furniture (Experiment 2, N = 213). Both experiments provide consistent evidence that high repetitiveness has a detrimental effect on well‐being, whereas work performance increases under conditions of high repetitiveness. On a practical level, our study hence shows that high task repetitiveness is a double‐edged sword for both employees and organizations. On a conceptual level, our findings emphasize the necessity to account for both mental strain and work performance when examining the effects of task repetitiveness. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
458.
Drawing on self‐determination and self‐concept‐based theories, this study investigated the mediating effects of psychological empowerment and organization‐based self‐esteem on the relationship between supervisory mentoring and employee performance and the moderating effect of supervisor political skill on the direct and first stage of the indirect effects. Data were obtained from a sample of 330 subordinate–supervisor dyads from the People's Republic of China. Using PROCESS of conditional indirect effect, we found support for the moderated direct and indirect effects of supervisory mentoring. First, supervisor political skill moderates the direct effect of supervisory mentoring on employee promotability. Second, supervisor political skill moderates the indirect effect of supervisory mentoring on the following: (i) employee promotability via both psychological empowerment and organization‐based self‐esteem and (ii) contextual performance only via psychological empowerment. These direct and indirect effects of supervisory mentoring are stronger when supervisors demonstrate a higher level of political skill. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
459.
This study describes a multilevel examination of person–group (PG) fit perceptions in a sample of 1023 individuals working in 92 teams at a private sector R&D firm. Using confirmatory factor analysis and multilevel random coefficient modeling, we provide evidence that perceptions of team‐level collective fit are unique from aggregated individual‐level PG fit perceptions at the individual and team levels. We demonstrate that collective values‐based and abilities‐based fit perceptions showed unique and positive relationships with team cohesion, team efficacy, and team performance, after accounting for aggregated individual perceptions of PG fit. Results also demonstrate that cohesion partially mediates the relationship between collective fit and team performance. Cross‐level effects were also supported, indicating that collective fit explains additional variance in individual‐level outcomes, beyond individual‐level PG fit perceptions. The usefulness of employing a multilevel approach to studying PG fit is discussed. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
460.
常天海  郑艳华  梁添 《安全》2005,26(3):28-30
阐述了危险品工作区域中人体静电防护的必要性,总结了人体静电的起因和危害形式,给出了危险品工作区域中人体静电隐患防护的几个方法.  相似文献   
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