常减压装置自燃危险分析及对策

通过对常减压装置内介质温度和自燃点的比较分析,绘制装置自燃危险分析图,确定自燃危险的重点防护区,并提出对策措施。     

Unraveling the impact of workforce age diversity on labor productivity: The moderating role of firm size and job security

Previous literature has suggested both positive and negative effects of age diversity on labor productivity: positive because of the potential knowledge complementarities between employees of different ages and negative because of the age‐related value differences that might reduce cohesion and cooperation, hampering firm performance. Using a Belgian sample of 5892 organizational observations (2008–2011), we unraveled these countervailing effects in two ways. First, we built on prior studies to suggest that the effect of age diversity depends on the particular shape of the age distribution: positive when it is heterogeneous (i.e., variety) and negative when it is polarized (i.e., polarization). This was supported by our findings. Second, we explored the moderating impact of two contextual contingencies, firm size and job security. As expected, the positive effect of age variety is reinforced in large firms and in firms where job security is high. Although firm size also emphasizes the negative effect of age polarization on productivity, job security, unexpectedly, does not moderate this relationship. Our study offers a valuable contribution to the literature as it reveals the boundary conditions of the competing implications of age diversity and, thus, allows one to account for the inconclusive findings reported in previous literature. Copyright © 2015 John Wiley & Sons, Ltd.     

表面喷丸对Aermet100钢耐蚀性影响

目的 探究表面喷丸处理对于Aermet100钢耐蚀性能的影响。方法 借助显微观察、电化学测量及XRD分析等手段,开展喷丸与未喷丸2类A100钢试件的中性盐雾试验。结果 腐蚀形貌上,两者腐蚀表面变化均为先出现红褐色物质,后出现红棕色与绿色絮状物,在出现变化的时间上相差约1个周期。随着腐蚀时间增长,XRD衍射峰发生右移,2类试件XRD结果均在144 h变化明显。中性盐雾试验电化学结果与海洋环境下电化学结果在溶液电阻、腐蚀产物电阻和腐蚀反应电阻上均有差异,自腐蚀电位略低,自腐蚀电流则低了2个数量级。结论 两者腐蚀现象规律一致,XRD衍射峰右移表明试件晶格参数变小。2类试件腐蚀速率呈现增加到减缓再到增加的趋势。喷丸能明显提高A100钢的耐蚀性。     

基于统计回归模型的硫化矿石自燃倾向性鉴定指标研究

合理的提出硫化矿石自燃倾向性的鉴定指标,准确鉴别其自燃倾向性,对于矿山防火工作有着重要的意义。本文采用应用非常广泛的一类随机模型—统计回归模型,首先通过分析硫化矿石自燃氧化机理,找到影响硫化矿石自燃倾向性的3个主要影响因素,实验获得相关数据;其次基于3个因素的数据,通过统计分析,建立回归模型,对硫化矿石自燃倾向性进行预测。     

煤炭自燃指标性气体确定的实验研究

矿井火灾是矿井五大灾害之一,煤炭自燃则是矿井火灾最主要的起因。为了了解煤炭氧化、自燃规律,本文采用TG-DSC技术研究了不同煤种在水分蒸发、吸氧增重、受热分解及燃烧等不同氧化阶段的氧化特征值;并采用TG-DSC-GC联用技术研究了不同煤种在整个氧化阶段的气体产物生成规律及其特征。在煤的低温氧化阶段,找出了CO等可作为判别煤自燃的指标性气体及C2H4等辅助指标性气体;并得出了各煤种氧化阶段的耗氧规律。     

Civilians under fire: evacuation behaviour in north Israel during the Second Lebanon War

This paper seeks to understand evacuation behaviour in a case of spontaneous evacuation. During the Second Lebanon War of 2006, more than one‐third of residents in north Israel spontaneously evacuated—the remainder stayed in situ. Using a telephone survey of 665 respondents residing in north Israel, we were able to characterise the behaviour of evacuees and non‐evacuees. The main reasons cited for evacuating were fear of injury to self or family, the effect on children, inability to remain in a protective space, and family pressure. The main reasons cited for remaining at home were no suitable alternative, did not perceive a high level of danger, had to go to work, and there is no place like home. There were no significant differences with regard to most socio‐demographic characteristics of the population. These findings should aid emergency managers in preparing the population for a future emergency and in engaging in effective dialogue with the population during an emergency on the evacuation option.     

高瓦斯易自燃工作面高抽巷瓦斯抽采与采空区遗煤自燃相互影响研究

为了实现瓦斯与煤自燃两大灾害的联合防治,首先对布置高抽巷条件下瓦斯与遗煤自燃多因素相互影响关系进行了理论分析和归纳总结。结合淮南潘二煤矿11223高瓦斯易自燃工作面,建立了带有高抽巷的物理模型,利用UDF编译了本煤层与邻近层瓦斯涌出源项、采空区三维孔隙率和低温条件下煤氧化反应氧气消耗速率。在此基础上,分析了高抽巷布置参数和抽采参数以及工作面风量对高抽巷瓦斯抽采效果和采空区自燃带分布相互影响的规律。结果表明,当工作面风量为2 000 m3/min,高抽巷布置在顶板上方40 m时,高抽巷瓦斯抽采浓度和纯量分别达32.3%和29.07 m3/min,占总瓦斯涌出量的69.71%,同时能满足实际防火的要求。研究结果可为类似条件下高抽巷最佳施工与抽采参数提供借鉴。     

Y形通风采空区自燃与有害气体排放的数值模拟

基于非均质多孔介质漏风渗流方程、多相气体渗流-扩散方程和多孔介质渗流综合传热方程,建立了采空区瓦斯与自燃发火耦合数值模型,开发了用迎风格式有限元方法联立求解的计算机程序(简称G3).计算以图形方式给出各量的区域分布解,从理论上描绘了Y形通风采空区的漏风流态,动态描绘了瓦斯、氧和CO的体积分数以及温度分布状态及其变化过程,并证明了Y形通风形式能避免采空区瓦斯向工作面涌出.计算中采空区按冒落非均质介质处理,考虑了瓦斯涌出对自燃的耦合作用,给出了这种耦合作用关系和解决办法.Y形通风采煤的自燃,两者存在着顾此失彼的关系.     

利用偏振-米散射激光雷达研究广州一次浮尘天气过程

利用偏振-米散射激光雷达、颗粒物监测仪数据,结合风廓线等气象资料分析讨论了2012年3月25日广州浮尘天气气溶胶污染事件,通过气团后向轨迹分析了沙尘气溶胶的来源及路径.结果表明本次污染过程与我国西北地区大部沙尘暴产生的浮尘远距离输送有关;浮尘期间相对湿度迅速下降,测点PM10中PM2.5所占的比例在28%~31%之间,与广州地区以细粒子污染为特征不同,本次气溶胶污染事件主要是由粗粒子引起;影响近地面的沙尘层主要分布高度在1000~2000m区域;沙尘过境期间探测到气溶胶最大退偏比为0.34.     

集对分析在煤炭自然发火危险性评价上的应用

为了解煤炭自然发火危险性程度,及时对采空区在发火前采取相关措施,对其进行发火危险性评价显得尤为重要。提出了基于集对分析的煤炭自然发火危险性评价方法,以集对分析理论为基础,将煤炭自然发火看成一个确定不确定系统,建立了煤炭自然发火评价模型。以梁家煤矿4110采空区为例,将计算结果与基于熵权未知理论的评价结果作比较,得出的结论一致。表明了集对分析运用在煤炭自然发火危险性评价上是可行的,可为矿井生产和其他系统的分析评价提供参考