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311.
Introduction: Construction sites exhibit unique hazardous characteristics. Hence, investigating the causes of fatal and nonfatal accidents is extremely important to promote safety on construction sites. Literature shows a risk perception (RP) scale for construction workers; to expand the existing research, this study aims to identify risky scenarios for assessing the RP of Thai construction workers, with the goal of reducing workplace incidents. Method: The scale development process consists of four phases. Item development was also performed, followed by factor analysis. Reliability and validity assessments were finalized in the process. A survey of 500 construction workers in Thailand was conducted to investigate risky scenarios. Through the process, a total of 17 items remained in the final RP scale, and the reliability and validity of these items were confirmed. Results: The RP scale was affirmed to have four dimensions (probability, severity, worry, and unsafe). These dimensions of workers’ RP were negatively correlated with the workers’ risk-taking behaviors. This study further showed that participants with a high level of affective RP were more likely to have a high level of cognitive RP. Hence, those with a high level of RP tended to be involved in fewer risk-taking behaviors. Practical Applications: The final version of the scale was reliable and valid in determining the RP and risk-taking behaviors of construction workers in Thailand.  相似文献   
312.
铜绿山矿冶废弃地优势植物重金属的积累与迁移   总被引:1,自引:0,他引:1  
通过野外调查和取样分析,研究了大冶铜绿山矿冶废弃地鸭跖草等5种优势植物对重金属的吸收累积与迁移特性,以期为矿区退化生态系统的植被恢复、重金属污染土壤的治理等提供依据。结果表明,鸭跖草等5种植物对重金属Cu、Pb、Zn、Cd、Cr都有程度不等的高量积累,尤其是铜元素,其最高积累量出现在海洲香薷根部,达到844.65 mg/kg,是一般植物Cu含量(5~25 mg/kg)的33.8~1689倍;而在同样条件下,As在5种植物体内的含量为018~098 mg/kg,远远低于As在一般植物中的含量(<10 mg/kg),这说明这些植物对As可能具有某种规避机制。从植物对重金属的吸收、富集和转运能力综合考虑,鸭跖草等5种植物都不太可能是重金属Cu等6种重金属的超累积植物。但是,它们对重金属所表现出的耐性无疑对矿冶废弃地的植被恢复过程有重要意义。  相似文献   
313.
We conducted experiments designed to examine the distribution of foraging honey bees (Apis mellifera) in suburban environments with rich floras and to compare spatial patterns of foraging sites used by colonies located in the same environment. The patterns we observed in resource visitation suggest a reduced role of the recruitment system as part of the overall colony foraging strategy in habitats with abundant, small patches of flowers. We simultaneously sampled recruitment dances of bees inside observation hives in two colonies over 4 days in Miami, Florida (1989) and from two other colonies over five days in Riverside, California (1991). Information encoded in the dance was used to determine the distance and direction that bees flew from the hive for pollen and nectar and to construct foraging maps for each colony. The foraging maps showed that bees from the two colonies in each location usually foraged at different sites, but occasionally they visited the same patches of flowers. Each colony shifted foraging effort among sites on different days. In both locations, the mean flight distances differed between colonies and among days within colonies. The flight distances observed in our study are generally shorter than those reported in a similar study conducted in a temperate deciduous forest where resources were less dense and floral patches were smaller.  相似文献   
314.
Selection procedure of the optimum station combination for decreasing the station number from 33 to 14 in water quality monitoring network of Gediz river basin was applied using an optimization method. Gediz basin is one of the important basins and it covers 2.3% of the total surface area of Turkey. The technique includes two stages as the data preparation and the optimization. In the data preparation stage, firstly, alternative station combinations decreased and then station combination scores obtained from assigned selection criteria for point and nonpoint pollution management objectives. Finally, genetic algorithm applied to select the best combination. The results were compared with a prior solution that used dynamic programming as the optimization technique.  相似文献   
315.
环境监测优化布点黑箱理论模型的研究   总被引:4,自引:1,他引:4  
张新华 《环境工程》1999,17(3):56-57
提出黑箱理论模型优化环境监测布点,根据Moore Penrose广义逆理论提出二次多项式方程的最小范数算式。应用于大气监测优化布点的实例结果表明,该方法用于监测优化布点是可靠的  相似文献   
316.
城市人居环境的可持续发展体系是一个由人口、社会、资源、环境与经济5个子系统构成的开放巨系统。通过提出综合衡量系统“协调性”和“发展水平”的“协调发展度”模型,研究人居环境复合系统内5个子系统之间协调发展度情况。并运用灰色预测理论构建GM(1,N)动态模型,预测未来几年各子系统之间协调发展的状况。  相似文献   
317.
高速公路桥头差异沉降综合处治对策   总被引:4,自引:0,他引:4  
由于台背路堤和桥台两者形成差异沉降,桥头跳车成为普遍且复杂的问题,对这一特殊路堤病害的成功处治尚不多见。近年来.加筋土结构的柔性桥台开始应用于工程实践,这种结构有可能从根本上防止桥头跳车的产生。本文针对高速公路桥头路基易产生差异沉降这一普遍现象,从理论与施工的角度进行探讨,并结合京珠高速公路粤境南段工程建设的实际,介绍了防止桥头跳车不良影响而采取的技术处理措施。经实践检验,综合处治对策取得了成功。  相似文献   
318.
现场土工监测对指导施工和保证工程质量具有重要的意义,郑州市东绕城公路(0107辅道)采用CJG-86 型PVC沉降管和CJH-88型沉降磁环进行土体分层沉降观测,得出了分层沉降的分布规律,为相关的公路工程设计与施工提供科学依据,同时为后续工作提供相应的借鉴。  相似文献   
319.
Chambers R 《Disasters》1982,6(1):21-30
Rapid change In rural Africa raises new policy problems In dealing with mass influxes of rural refugees. Self-settlement in agriculture has become less feasible and is less acceptable now that Its disadvantages are better understood. Organized smallholder settlement can be a better solution where it is economically viable, refugees have freedom of movement, and staff are suitable. But growing land shortage means that Increasing proportions of refugees are being placed in camps. To offset this trend, more attention is suggested to programmes for groups of refugees, categorized by time of arrival, by ability to self-settle or to farm, and by skills and experience. Practically-oriented social science research can contribute to these and other approaches which will require imagination and ingenuity. Solutions to future rural refugee problems should be linked with programmes of social and economic development which will make easier the achievement of humanitarian objectives.  相似文献   
320.
李天魁  刘毅  谢云峰 《中国环境科学》2018,38(10):3985-3992
通过污染物迁移转化多介质模型-EPACMTP模型,使用区域灵敏度分析、全局灵敏度分析与实证案例验证等方法,对风险筛查指标体系的指标完备性、权重与赋分合理性及判断可靠性进行了研究.结果表明,除渗滤液浓度外,风险筛查指标涵盖了所有灵敏度显著的参数(13个);对于大部分灵敏度或重要性较高的参数给予了较大权重,对重点区域面积、离最近敏感目标的距离等两项指标的赋分整体合理;对低污染场地的判断结果较为可靠.最后,本文建议风险筛查过程中进一步提高对污染物迁移过程的关注,对指标内部分级与赋分进行调整,并重点关注中高风险场地与砷污染场地.  相似文献   
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