区域性煤矿百万吨死亡率指标的宏观预测研究

为了对煤矿安全状况进行宏观预测,提出区域性煤矿安全状况评价指标体系并建立了以煤矿百万吨死亡率指标标征区域性煤矿安全状况的灰色预测模型。在对煤矿综合机械化采煤率、大型煤矿产量比例、原煤全员效率指标预测分析的基础上,利用多元回归法综合预测煤矿百万吨死亡率指标。实例计算证明:建立的预测模型具有输入数据少、建模简单、计算快捷等优点;客观地反映出区域性的煤矿安全状况;该模型可进行煤矿安全的短期预测,并为制定煤矿安全控制指标提供理论依据。     

汽车气制动ABS调节阀测试系统气动测试回路设计研究

针对气制动防抱死制动系统(ABS)调节阀测试系统气动回路设计进行研究;根据我国的汽车生产和检测现状,在确定气动测试回路总体方案的基础上,进行主控部分、负载回路、控制回路的设计和计算,所设计的气路检测系统可用于测试8种典型的气制动元件的密封性及动静态特性,通过不同的组合能够满足每一种阀的测试需求。该气动测试回路有效解决了简单阀类测量方法的不足,满足不了生产率及测量精度要求的问题。     

层次分析法在高层学生公寓火灾危险性评价中的应用

分析高层学生公寓的消防安全特点及其火灾发生危害性,评述现有的高层建筑火灾风险评价方法;在现有的评价方法的基础上,从人员因素、建筑物属性、安全疏散设施、报警与灭火系统、防火与防烟系统、建筑物内电气因素和消防安全管理7个方面综合考虑,建立了高层学生公寓的建筑火灾危险评价指标体系;利用层次分析法对高层学生公寓火灾危险性进行分析,确定其评价指标体系中各层次各指标的权重;分析结果表明:消防安全教育与培训是学生公寓火灾危险评价指标体系中最重要的因素。加强和改进高层学生公寓消防安全管理,对预防或减少高层学生公寓火灾具有现实指导价值。     

道路交叉口冲突仿真分析

针对基于事故的安全评价在数量、周期、均值、随机性等方面以及基于现场冲突观测识别在主观性、可靠性、成本、指标全面性等方面存在的问题,提出基于冲突仿真的交叉口安全预评价分析方法:研究利用安全间接分析(SSAM)模型分析冲突的基本原理和冲突时间(TTC)、遭遇时间(PET)等分析指标的计算方法;以及利用VISSIM仿真软件进行冲突仿真分析应注意的策略。以邢台市某道路交叉口安全改善方案为例,进行改善前后冲突仿真的比较分析。研究结果表明,改善后在通行效率显著提升的同时,交叉、追尾、车道变换冲突的数量均显著减少,TTC值有所增加,说明改善后安全程度有所提升。笔者提出的方法和案例应用为道路交叉口改善措施的安全预评价提供了一种分析途径和有益借鉴。     

基于模糊影响图方法的库存弹药事故概率分析

针对库存弹药安全的特殊性,在分析国内外库存弹药典型事故案例的基础上,指出FTA、ETA等传统概率计算方法存在的局限。提出一种基于模糊影响图(FID)的库存弹药事故概率分析方法,并对FID模型的构建过程和算法进行概述;以弹药被盗事故作为实例分析,并得到事故概率分布图和累积概率曲线。结果表明,FID的算法理论及建模过程能较好地克服FTA、ETA等传统方法的局限性,实例分析指出弹药被盗事故在10-4数量级的隶属度最高,且事故发生概率更趋向于10-3～10-1数量级,从而得到一旦仓库安全防范措施不到位,就很有可能发生弹药被盗事故的结论。     

矿井通风系统安全性的多层次模糊综合评价

按照事故致因理论,并进行系统安全分析和易发事故分析,建立了矿井通风系统安全性的多层次评价体系;应用层次分析法和Matlab软件,确定矿井通风系统安全性评价体系中各子系统及各指标的权重;结合实际经验,根据安全规范构造各指标隶属度;进而根据评价集构造了梯形分布的隶属函数,并得到各指标对评价集的最终隶属度、模糊关系矩阵和综合评价矩阵;求得矿井通风系统安全状况的综合得分,进而划分安全评价等级,并提出了对应各等级的处理措施。将该评价方法应用到重庆开县桃园联合煤矿,取得了良好的效果。     

Seasonal Differences in the Levels of Gaseous Air Pollutants in the Vicinity of a Waste Dump

Hydrogen sulphide, ammonia, nitrogen dioxide, mercaptans and sulphur dioxide (H₂S, NH₃, NO₂, R-SH, SO₂) concentrations were measured at the location in the vicinity of the waste dump to determine the air pollution level of these pollutants prior to the operation of the Mobile Thermal Treatment Plant. Samples were collected over one year period. Seasonal differences, and the influence of meteorological parameters (temperature, relative humidity, pressure and wind direction) on the air pollution levels were studied. Results show relatively low concentrations of H₂S, NO₂, R-SH and SO₂, while NH₃ levels were higher compared to the guideline values. Good weather conditions (high air pressure and low relative humidity) are connected to long range transport of NO₂, while higher temperatures result in elevated NH₃ and R-SH concentrations. Because of the predominant northeast wind direction (the same as the waste dump direction), the contribution of air pollution from the direction of the waste dump at the measuring site is significant, but that does not necessarily mean that the pollutants originated from that source.     

一体化生活污水处理构筑物的设计思路与实践

根据生活水一体化处理设备的原理及构思,将通用设备替代为组合的一体化构筑物形式,应用于生活污水处理中,取得了良好的经济效果和较优的技术稳定性,达到了水处理单元优化设计的目的。     

Fecal source tracking by antibiotic resistance analysis on a watershed exhibiting low resistance

The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was to test the efficiency of the antibiotic resistance analysis (ARA) method under low resistance by tracking the fecal sources at Turkey Creek, Oklahoma exhibiting this condition. The resistance patterns of 772 water-isolates, tested with nine antibiotics, were analyzed by discriminant analysis (DA) utilizing a five-source library containing 2250 isolates. The library passed various representativeness tests; however, two of the pulled-sample tests suggested insufficient sampling. The resubstitution test of the library individual sources showed significant isolate misclassification with an average rate of correct classification (ARCC) of 58%. These misclassifications were explained by low antibiotic resistance (Wilcoxon test P < 0.0001). Seasonal DA of stream E. coli isolates for the pooled sources human/livestock/deer indicated that in fall, the human source dominated (P < 0.0001) at a rate of 56%, and that human and livestock respective contributions in winter (35 and 39%), spring (43 and 40%), and summer (37 and 35%) were similar. Deer scored lower (17–28%) than human and livestock at every season. The DA was revised using results from a misclassification analysis to provide a perspective of the effect caused by low antibiotic resistance and a more realistic determination of the fecal source rates at Turkey Creek. The revision increased livestock rates by 13–14% (0.04 ≤ P ≤ 0.06), and decreased human and deer by 6–7%. Negative misclassification into livestock was significant (0.04 ≤ P ≤ 0.06). Low antibiotic resistance showed the greatest effect in this category.     

Accumulation of Heavy Metals in Epiphytic Lichens Near a Municipal Solid Waste Incinerator (Central Italy)

The epiphytic lichen Parmelia caperata was usedas biomonitor in the area of a municipal solid wasteincinerator (Poggibonsi, central Italy) to investigatethe levels and the spatial distribution of the heavymetals Al, Cd, Cr, Cu, Fe, Hg, Pb and Zn. Levels ofAl, Cu and Hg were similar to those in unpollutedareas, whereas high values were found for Cr, Zn andespecially Cd. The distribution pattern of the lastthree metals and the exponential relationship of theirconcentrations with distance from the incinerator,showed that the disposal plant is a local source ofatmospheric pollution due to Cd, Cr and Zn. For thesemetals, long-term hazard should be seriously taken into account.