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81.
利用放射性同位素(137Cs、210Pb)测年法计算山东省南四湖的沉积速率,采用高纯锗γ谱仪(美国EG&G ORTEC公司)对南四湖上级湖、下级湖的沉积岩柱(DS2和WS2)样品进行137Cs、210Pb放射性活度测试,分析水利工程建设对湖泊沉积影响的程度与后果. 结果表明:上级湖、下级湖137Cs总蓄积量之比为9.7,说明在二级坝水利工程影响下,流域内侵蚀泥沙及其所吸附的137Cs主要沉积于上级湖;137Cs在湖泊沉积物中的剖面分布与137Cs大气沉降时序的分布模式相背离,故137Cs蓄积峰不具备时标意义. 利用210Pb计年的CRS(恒定补给速率)模式分析2个沉积岩柱不同质量深度所对应的年代,结果显示,150多年来南四湖上级湖、下级湖的沉积速率不稳定,以1960年为界划分为两大时段:沉积岩柱底部所对应的年代至1960年,上级湖、下级湖沉积速率平均值分别为0.069、0.160 g/(cm2·a);1960—2010年,二者沉积速率平均值分别为0.218、0.072 g/(cm2·a). 可见,二级坝水利工程对南四湖沉积速率产生了重要影响,210Pb计年的CRS模式分析结果可靠.   相似文献   
82.
When a team is analyzing a LOPA scenario, the team needs to consider all three roles played by human interaction in the scenario: that of cause, as a result of human error; that of receptor, both in terms of safety impacts (inside the fence line) and community impacts (outside the fence line); and that of independent layer of protection (IPL), considering both administrative controls and human responses. Frequently, the nature of these three roles are inter-related, and setting guidance that is internally consistent is important to using LOPA to assess risk rather than as a means to game the analyses to simply achieve a wished-for result.A number of criteria have been proposed to quantify human involvement, typically as cause, as receptor, or as IPL. Establishing a framework to look at all three in a unified way is more likely to result in analyses that are consistent from scenario to scenario.This paper describes such a framework and presents it in a way that allows organizations to review their own criteria for quantifying human involvement in LOPA. It also examines some of the published LOPA criteria for human involvement and looks at them in terms of consistency of approach between evaluation of cause, receptor, and IPL. Finally the paper makes suggestions to use in calibrating LOPA methodologies to achieve consistent and believable results in terms of human interaction within and between scenarios that have worked for other organizations.  相似文献   
83.
煤矿人为失误的原因及控制   总被引:2,自引:0,他引:2  
随着科学技术的进步,机器设备的可靠性得到了大幅度的提高,人为失误导致的事故比例快速上升.掌握人为失误的原因,进而控制人为失误的发生是有效减少事故发生的重要措施.在对神火煤电股份有限公司新庄矿深入调查了解的基础上,初步探讨了煤矿人为失误的原因,提出了控制人为失误的有效途径.  相似文献   
84.
空中相撞事故往往是由诸多人为差错相互叠加、耦合和作用而导致的,要找出事故的真正诱因,防止类似事故再次发生,难度非常大。为了有效地分析和定位人为差错,以更好地服务于防相撞的管理与决策,提出一种基于人为因素分析分类系统(HFACS)的空中相撞事故分析方法,它按照从显性差错到隐性差错的思路来分析事故的诱因,最终找出组织因素对事故的影响。并利用HFACS对巴西卡欣布上空发生的一起空中相撞事故进行了系统分析。案例分析结果表明,该方法不仅能够找出导致空中相撞事故的人为差错,解释事故发生的原因和过程,而且能够据此提供防止相撞事故发生的安全建议。  相似文献   
85.
曹妃甸老龙口现代沉积环境及重金属污染特征研究   总被引:2,自引:0,他引:2       下载免费PDF全文
利用测年、重金属测定、粒度测定等方法,对河北曹妃甸老龙口区域的7个柱状沉积物进行了粒度、沉积物的测年、重金属含量测定和分析,探讨潮滩重金属沉积的控制因素和迁移规律.结果显示,老龙口潮滩属于细沙和粉沙,根据同位素测年结果,L06沉积速率最大,为0.90cm/a;其余柱状样沉积速率均小于0.5cm/a,平均沉积速率为0.32cm/a,曹妃甸潮滩属于缓慢沉积;柱状样垂直方向波动剧烈,受人类活动影响明显.重金属的含量在柱样的30~40cm深度呈现向表层递增的趋势,Hg、Cr的污染比较严重、其他元素基本无污染.虽然多数重金属元素在背景值附近没有出现污染现象,生态危害性极低,但是,受Pb、Hg中度重金属生态危害的影响,该区域多种重金属生态危害指数(ERI)达158.41,表现为中等程度的生态危害性;存在一定的潜在生态风险.  相似文献   
86.
In the Netherlands there are around 400 “Seveso” sites that fall under the Dutch Major Hazards Decree (BRZO) 1999. Between 2006 and 2010 the Dutch Labour Inspectorate's Directorate for Major Hazard Control completed investigations of 118 loss of containment incidents involving hazardous substances from this group. On the basis of investigation reports the incidents were entered in a tailor-made tool called Storybuilder developed for the Dutch Ministry of Social Affairs and Employment for identifying the dominant patterns of technical safety barrier failures, barrier task failures and underlying management causes associated with the resulting loss of control events. The model is a bow-tie structure with six lines of defence, three on either side of the central loss of containment event. In the first line of defence, failures in the safety barriers leading to loss of control events were primarily equipment condition failures, pre start-up and safeguarding failures and process deviations such as pressure and flow failures. These deviations, which should have been recovered while still within the safe envelope of operation, were missed primarily because of inadequate indication signals that the deviations have occurred. Through failures of subsequent lines of defence they are developing into serious incidents. Overall, task failures are principally failures to provide adequate technical safety barriers and failures to operate provided barriers appropriately. Underlying management delivery failures were mainly found in equipment specifications and provisions, procedures and competence. The competence delivery system is especially important for identifying equipment condition, equipment isolation for maintenance, pre-start-up status and process deviations. Human errors associated with operating barriers were identified in fifty per cent of cases, were mostly mistakes and feature primarily in failure to prevent deviations and subsequently recover them. Loss of control associated with loss of containment was primarily due to the containment being bypassed (72% of incidents) and less to material strength failures (28%). Transfer pipework, connections in process plant and relief valves are the most frequent release points and the dominant release material is extremely flammable. It is concluded that the analysis of a large number of incidents in Storybuilder can support the quantification of underlying causes and provide evidence of where the weak points exist in major hazard control in the prevention of major accidents.  相似文献   
87.
Introduction. Rates of aviation accident differ in different regions; and national culture has been implicated as a factor. This invites a discussion about the role of national culture in aviation accidents. This study makes a cross-cultural comparison between Oman, Taiwan and the USA. Method. A cross-cultural comparison was acquired using data from three studies, including this study, by applying the Human Factors Analysis and Classification System (HFACS) framework. The Taiwan study presented 523 mishaps with 1762 occurrences of human error obtained from the Republic of China Air Force. The study from the USA carried out for commercial aviation had 119 accidents with 245 instances of human error. This study carried out in Oman had a total of 40 aircraft accidents with 129 incidences. Results. Variations were found between Oman, Taiwan and the USA at the levels of organisational influence and unsafe supervision. Seven HFACS categories showed significant differences between the three countries (p?<?0.05). Conclusion. Although not given much consideration, national culture can have an impact on aviation safety. This study revealed that national culture plays a role in aircraft accidents related to human factors that cannot be disregarded.  相似文献   
88.
旋转压缩机油路系统仿真与试验研究   总被引:1,自引:0,他引:1  
压缩机泵油系统对滚动转子压缩机性能和可靠性非常重要.为了了解压缩机泵油特性.本文应用CFD软件,采用VOF模型对滚动转子压缩机整个泵油系统进行数值模拟,搭建试验台进行试验,并将模拟和试验结果进行对比,结果表明上法兰螺旋槽处润滑油流量结果吻合很好,误差在10%以内,证明了该仿真方法的可行性.  相似文献   
89.
目前国内外对环境电磁波的测量仪器主要分为两类,分别是选频式和非选频式。选频式仪器由各类测量接收机或频谱分析仪和接收天线组成,其不适于非周期信号测量。非选频式仪器由各类全向型探头和主机组成,适用于周期和非周期信号的环境电磁波测量,但这类仪器动态范围不高。本文采用了两种不同的测量仪器,分别以单频连续波和调制脉冲为激励信号进行比较分析。结果表明:随着测量信号电平增加,两种仪器测量结果数据趋于一致。而在用两种标准的不同方法计算某一频段的复合场强时,其数值有较大差异。  相似文献   
90.
航空维修差错模式及差错成因的灰色关联分析   总被引:3,自引:2,他引:1  
提出一种基于HFACS-ME框架和灰色关联分析法的航空维修差错模式和差错成因之间关系的分析方法。利用该方法分别从"模式—成因"和"成因—模式"2个方向,以"技能差错"和"身体状态差"为例,对差错模式和差错成因之间的关系进行分析,得到影响"技能差错"的主要差错成因依次为空间狭窄、培训不足、工具损坏、身体状态差、精神状态差、空间阻碍,以及"身体状态差"主要影响的差错模式为记忆差错、决策差错、技能差错。结果表明,灰色关联分析法对航空维修差错模式和差错成因之间关系的分析是有效的、可行的。  相似文献   
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