城际列车活塞风对地下车站排烟效果的影响

列车在区间隧道行进过程中,空气受挤压作用会在隧道内形成活塞风,活塞风对烟气扩散有一定的影响.为探明携火列车停站后活塞风衰减过程及其对车站轨行区上排烟系统的排烟效果影响规律,采用Fluent软件中的动网格模拟技术及Layering方法更新网格,对城际列车着火驶向地下车站及城际列车静止着火进行了仿真计算.结果表明:1)对比不同站台类型隧道列车停站后活塞风衰减过程,进站端活塞风风速均高于出站端且均在5 min后达到稳定;2)对比有无活塞风情况下地下车站排烟效果,无活塞风情况下地下车站排烟效率呈对称分布,有活塞风时地下车站排烟效率呈不对称分布;3)对比不同站台类型隧道的地下车站排烟效果,有活塞风情况下岛式站台隧道的排烟系统总排烟效率高于侧式站台隧道总排烟效率;4)岛式站台隧道无活塞风工况总排烟效率一直维持在85％左右,有活塞风工况排烟系统总排烟效率在4 min以后增至85％,最高达到90％;侧式站台隧道排烟系统总排烟效率在5 min以后增至80％左右.研究结果可为城际地下铁路车站的排烟系统设计提供参考.     

Assessing diversity climate: A field study of reactions to employer efforts to promote diversity

Based on intergroup theory, this study examined relationships among group characteristics (racioethnicity, gender, and level), contextual organizational unit characteristics (gender and racioethnic heterogeneity, resource support for women and racioethnic minorities) and perceptions of diversity climate by faculty at a large university. Compared to white men, white women and racioethnic minorities placed greater value on employer efforts to promote diversity, and held more favorable attitudes about the qualifications of women and racioethnic minorities. The study found that group rather than contextual organizational unit characteristics were more strongly related to diversity climate. However, the organizational unit characteristic, gender heterogeneity, was significantly related to valuing diversity. The greater the ratio of women in a unit, regardless of the respondents' gender, racioethnicity or level, the more favorable diversity activities were viewed. In addition, units whose allocation of resources to racioethnic minorities were perceived as insufficient by respondents were more likely to have members who valued diversity and held favorable perceptions toward the qualifications of racioethnic minorities. Implications for organizations and future research are offered.     

Safety climate in Finnish- and Swedish-speaking companies.

The aim of this study was to compare assessments made by Finnish- and Swedish-speaking workers in Finland about the safety climate in their companies, because an earlier study showed that the accident frequency of Swedish-speaking workers was one third lower than that of Finnish-speaking workers. 148 Finnish-speaking and 138 Swedish-speaking workers from 14 small and medium-sized companies participated in this study. They filled out a Finnish safety climate questionnaire, the reliability of which was above the acceptable level. There were no differences between the language groups in the total variables of safety climate and safety action. Based on the differences in single items, we interpreted that Swedish-speaking workers stressed collective safety more, whereas Finnish-speaking workers put more emphasis on their personal responsibility for safety.     

Measuring climate for work group innovation: development and validation of the team climate inventory

This paper reports the development and psychometric validation of a multi-dimensional measure of facet-specific climate for innovation within groups at work: the Team Climate Inventory (TCI). Brief reviews of the organizational climate and work group innovation literatures are presented initially, and the need for measures of facet-specific climate at the level of the proximal work group asserted. The four-factor theory of facet-specific climate for innovation, which was derived from these reviews, is described, and the procedures used to operationalize this model into the original version measure described. Data attesting to underlying factor structure, internal homogeneity, predictive validity and factor replicability across groups of the summarized measure are presented. An initial sample of 155 individuals from 27 hospital management teams provided data for the exploratory factor analysis of this measure. Responses from 121 further groups in four occupations (35 primary health care teams, 42 social services teams, 20 psychiatric teams and 24 oil company teams; total N=971) were used to apply confirmatory factor analysis techniques. This five-factor, 38-item summarized version demonstrates robust psychometric properties, with acceptable levels of reliability and validity. Potential applications of this measure are described and the implication of these findings for the measurement of proximal work group climate are discussed. © 1998 John Wiley & Sons, Ltd.     

The impact of organizational climate on safety climate and individual behavior

Relatively little previous research has investigated the meechanisms by which safety climate affects safety behavior. The current study examined the effects of general organizational climate on safety climate and safety performance. As expected, general organizational climate exerted a significant impact on safety climate, and safety climate in turn was related to self-reports of compliance with safety regulations and procedures as well as participation in safety-related activities within the workplace. The effect of general organizational climate on safety performance was mediated by safety climate, while the effect of safety climate on safety performance was partially mediated by safety knowledge and motivation.     

Occupational exposure to power frequency fields in some electrical transformation stations in Romania.

The aim of this study is to investigate the levels of electric and magnetic power frequency fields at 8 electrical transformation stations in the North-East counties of Romania and to check their compliance with standards. Spot measurements were carried out on both electric and magnetic fields under overhead conductors of 110-, 220- and 380-kV installations. The magnetic field levels were several orders of magnitude below the reference level for occupational exposure set by ICNIRP (International Commission on Non-Ionizing Radiation) or by Romanian regulations. In contrast, the electric field levels were about the same order of magnitude as the reference levels. In 2 electrical stations the reference level of 10 kV/m was exceeded at specific locations within the outdoor installations area. However, the additional reference level for short-time exposure included in Romanian regulations, 30 kV/m, was not exceeded.     

广义最大覆盖模型在消防站优化选址中的应用

针对目前我国城市消防站建设存在的数量不足、责任区面积过大、选址缺乏科学性等问题,引入广义最大覆盖模型,探讨城市消防站的优化选址方法.广义最大覆盖模型很好地解决了传统最大覆盖模型中假设覆盖度为二元值的缺陷,通过分段递减函数,将覆盖度表示为0～1之间的连续值,实现了供应点对所有需求点的覆盖.同时,本研究还考虑不同区域的火灾风险等级并设定了相应响应时间限值,通过对最短响应时间和响应时间限值的比较,得出候选消防站点对各个需求点的覆盖度水平.通过实例对广义最大覆盖模型的有效性进行验证,并利用LINGO软件进行求解.研究表明,广义最大覆盖模型可实现供应点以不同程度覆盖所有需求点,更适用于消防站类应急设施的选址问题.     

Deriving the factor structure of safety climate scales

Since the original formulation of the notion of safety climate, many people have developed safety climate measures and conducted factor analyses to identify distinct dimensions. Typically, these analyses were based on samples of workers in a limited number of workplaces, but since they did not allow for the non-independence of the data, they are incorrect. An appropriate analysis should use a multi-level method. This flaw in the analyses to date may at least partly explain the different factor structures of safety climate reported in the literature.     

A study of the workload of underground trammers in the Ranigang coal field area of West Bengal, India.

Thirty healthy trammers were examined in underground haulage mines during their normal activity. Physiological strain in terms of heart rate (HR) varied between 101.6 and 104.7 beats/min with mean net cardiac cost of 33.06 and 34.06 beats/min for younger and older groups respectively. The average relative cardiac cost was lower for younger subjects than for older ones. Oxygen consumption (VO2) was measured with an Oxylog-II machine (UK); subsequently values were estimated. Maximum aerobic capacity was estimated with an indirect method following a standard step test protocol. The responses revealed that the average VO2 during the activity was 0.75 and 0.8 L/min, which corresponded to energy expenditure (EE) of 3.8 and 3.97 Kcal/min for younger and older subjects respectively. The workload in terms of HR and EE was moderate, whereas the aerobic strain experienced by aged workers was above the acceptable level.     

矿井避难硐室防护系统研究

根据避难硐室的防护功能,确定防护系统由防火防爆、密闭、供氧、制冷除湿、监测监控、动力、通讯、定位、照明、医疗、食品、水、卫生几大系统组成;通过理论分析,确定防火防爆密闭系统抗爆压力影响因素为反射压力、入射压力、静压载荷、门体材料及安全系数;通过计算,可得100人避难硐室压风供氧系统总供风量不得低于36m3/min,其他供氧方式的最小供氧量不得低于60L/min。为避难硐室防护系统研究提供了科学依据及可靠数据,为矿井紧急避险系统的研究奠定了基础。     

城市地下管线系统可靠性分析

随着城市经济水平的提高、城市规模的扩大和现代化步伐的加快,城市地下管网越来越庞大,越来越复杂,种类也越来越多,所担负的城市人民群众赖以生存的物质基础的作用也越来越强。对城市地下管线失效的特点和系统可靠性进行深入分析,为政府部门做好日常安全管理工作,做出科学合理的决策,实现地下管线安全预警等提供依据,对预防事故发生和减少生命财产损失具有现实的指导意义。     

Assessing the reliability of diverse fault-tolerant software-based systems

We discuss a problem in the safety assessment of automatic control and protection systems. There is an increasing dependence on software for performing safety-critical functions, like the safety shut-down of dangerous plants. Software brings increased risk of design defects and thus systematic failures; redundancy with diversity between redundant channels is a possible defence. While diversity techniques can improve the dependability of software-based systems, they do not alleviate the difficulties of assessing whether such a system is safe enough for operation. We study this problem for a simple safety protection system consisting of two diverse channels performing the same function. The problem is evaluating its probability of failure in demand. Assuming failure independence between dangerous failures of the channels is unrealistic. One can instead use evidence from the observation of the whole system's behaviour under realistic test conditions. Standard inference procedures can then estimate system reliability, but they take no advantage of a system's fault-tolerant structure. We show how to extend these techniques to take account of fault tolerance by a conceptually straightforward application of Bayesian inference. Unfortunately, the method is computationally complex and requires the conceptually difficult step of specifying ‘prior’ distributions for the parameters of interest. This paper presents the correct inference procedure, exemplifies possible pitfalls in its application and clarifies some non-intuitive issues about reliability assessment for fault-tolerant software.     

Assessing the completeness of a job analysis procedure

The current research analyzed employee perceptions of the completeness of a self-report, point-factor job evaluation system. Complementary qualitative and quantitative techniques were used to identify characteristics of jobs, characteristics of employees, and characteristics of the job evaluation procedure that affected employee perceptions of the system. Analyses indicated that the job evaluation instrument might describe some classes of jobs more completely than others. Situations where job evaluation is particularly problematic are identified and discussed.     

非煤地下矿山安全管理研究

本文首先分析了我国非煤地下矿山严峻的安全形势,并从人、物、机、环境、管理五个方面分析了事故多发的原因,然后对我国非煤地下矿山主要事故隐患进行了分类介绍,最后提出了我国非煤地下矿山安全生产水平的对策。     

改进突变理论在井下排水方案优选中的应用

为了更精确合理地对新桥硫铁矿排水方案进行优选,对利用突变理论的方法进行优化,建立突变理论和熵权法相结合的改进模型。从经济和工程量方面出发,综合考虑了影响排水方案优选的3个层次的12个指标,统计样本数据。运用熵权法分层确定同一上层变量下各指标的客观权重,导入突变理论中,建立综合评价结构模型,消除了主观因素的影响。同时运用突变理论和EM-TOPSIS进行方案优选,通过对比3种方法的优选结果,证明了改进突变理论的可靠性与合理性。     

地铁区间隧道烟气层化现象研究

以重庆某一地铁区间隧道为原型,搭建了1∶15小尺寸隧道试验台,通过小尺寸试验与FDS 6.5.2数值模拟开展隧道顶部烟气温度分布及分层规律研究。基于Newman提出的烟气层分区条件,研究了不同纵向风速下的烟气分层现象,提出了烟气稳定层化长度的概念,并分析了火源热释放速率及断面型式对烟气层化长度的影响。试验证明了Newman提出的烟气分层计算方法是可信的。结果表明:纵向风速较小时,火源下游能呈现烟气分层现象;烟气稳定层化长度受火源热释放速率影响较大,随热释放速率增大而增大;隧道高度的变化对烟气稳定层化长度的影响较小。     

基于PHAST软件的站场冷放空燃爆事故模拟分析

为提高天然气长输管道阀室冷放空作业的安全性,针对冷放空作业中的意外闪燃、爆燃事故现象,基于UDM模型并运用PHAST计算机软件,先模拟了泄放气体发生闪燃事故的影响域,分析冷放空气体闪燃范围随风速、大气稳定度、放空压力及放空速率4种影响因素而变化的趋势;后又讨论了放空速率对爆燃超压伤害范围的影响。结果表明:闪燃范围随风速、大气稳定度、放空压力及放空速率增加而递增,后两者对其影响较大,应重点关注并控制;在模拟工况下,最远轻伤距离达60 m,因此在实际工程中,控制放空速率对减轻意外燃爆事故的后果极为重要,应注重对放空作业参数的调整。     

北京地区加油站安全现状及对策措施

近年来,随着城市交通和车辆的迅速发展,加油站如雨后春笋般建立.北京地区现有加油站1100多个,遍布北京市主要交通干线的周边地区.     

An empirical investigation of the influence of safety climate on organizational citizenship behavior in Taiwan's facilities.

Although the social exchange relationships between employers and employees are increasingly important to the performance of safety management systems, the psychological effects of work attitudes on this relationship have been less studied. Using a sample of first-line operators and their supervisors from 188 facilities in Taiwan which had Occupational Health and Safety Assessment Series 18000 (OHSAS 18000) certification, the current research conducted an empirical investigation of the influence of safety climate on organizational citizenship behavior (OCB). Work attitude was used to disclose the psychological effect. Research results indicated that (a) safety climate was a significant predicator of OCB, (b) the psychological effect significantly influenced social exchange relationships, and (c) job satisfaction showed a stronger mediating influence than organizational commitment due to the frequent top management turnover. Discussions and implications are also addressed.