不同助燃剂对松木燃烧痕迹的影响

本文主要叙述模拟汽油火场实验,主要以松木和95#汽油、油漆稀料为研究对象,模拟松木家具被泼洒助燃剂后燃烧,调查人员通过扫描电镜分析技术对松木表面燃烧痕迹进行分析,从松木燃烧痕迹微观形貌特征变化入手分析火场是否存在助燃剂,再结合能谱仪对松木燃烧残留物进行元素成分分析,进一步精确火场是否存在助燃剂。本文旨在利用SEM技术,得到具体可行的理论体系,为火灾物证鉴定提供新的辅助方法,为以后火灾调查人员在调查放火案件时关于鉴定火场是否存在助燃剂汽油提供一定的参考意见。     

火灾中聚合物材料热解对汽油辨识的影响分析

火灾中聚合物材料的燃烧过程产生的热解产物,从而增加化学分析谱图的复杂性,对助燃剂鉴定造成干扰。针对常见的聚合物材料开展了一系列燃烧实验,对其在燃烧过程中的热解机理进行了分析,并通过汽油存在条件下的聚合物材料燃烧实验分析了热解对汽油辨识产生的干扰。     

火场残留助燃剂的提取分离及气相色谱/质谱分析

本文总结了从火灾现场提取样品中分离残留助燃剂的常用方法,比较了各种不同分离方法的优缺点及主要适用对象,并介绍了常见助燃剂的典型气相色谱/质谱图特性,为火灾调查识别的研究提供理论指导。     

F&EI评价法在汽车加油站安全评价中的应用

运用"道化学公司火灾、爆炸危险指数评价方法"对加油站的埋地汽油储罐和埋地柴油储罐进行安全评价,并提出相关的注意事项.     

F&EI评价法在汽车加油站安全评价中的应用

运用"道化学公司火灾、爆炸危险指数评价方法"对加油站的埋地汽油储罐和埋地柴油储罐进行安全评价,并提出相关的注意事项.     

F&EI评价法在汽车加油站安全评价中的应用

运用"道化学公司火灾、爆炸危险指数评价方法"对加油站的埋地汽油储罐和埋地柴油储罐进行安全评价,并提出相关的注意事项.     

汽油介质储输运过程火灾爆炸危险性研究

由于汽油特殊的物化性质,在储输运过程中一旦发生泄漏极易造成火灾、爆炸事故, 从而导致重大人员伤亡及财产损失.针对汽油池火灾、流淌火灾及受限空间蒸气爆炸3种事 故形式,深入分析研究了它们的特点、特性参数及危险程度,为汽油储输运事故应急抢险方案的制定和具体实施提供参考.     

基于静态特征和动态行为的火灾检测模型*

为实时准确地检测视频监控的火灾信号,减少火灾误报,提出1种基于静态特征和动态行为的火灾检测方法。利用改进的Faster RCNN检测模型,根据可疑火灾区域的颜色特征和空间特征对其进行目标检测和特征降维,与传统的Faster RCNN相比平均检测精度提升5%;利用ILSTM对连续帧中的特征进行累加,对短期内是否发生过火灾进行分类。连续的短期决策在1min内以多数票表决最后决策。结果表明:方法将火灾检测的准确率提升到97.92%,并成功解释火焰和烟雾的时间行为。     

基于点源模型的拱顶罐池火灾热辐射通量分析

针对目前油品储罐区火灾爆炸事故处置缺少必要理论指导的现状,运用点源模型对常见公称尺寸的拱顶汽油、煤油和柴油储罐全面积池火的热辐射通量进行分析,探讨了油罐直径对点源模型计算结果的影响、水平热辐射通量与总热辐射通量的关系以及相同距离处被辐射目标物接受的热辐射通量随其高度位置的变化.提出了采用罐壁点源方法估算拱顶罐池火灾热辐射通量的建议,推荐采用汽油池火的热辐射通量进行油罐火灾热辐射危险性分析及消防安全设计方面的探讨.     

建筑物火灾危险性评估的一种工程方法

提出了建筑物火灾危险性评估的一种工程方法。该方法基于建筑火灾的区域模拟理论和人员疏散的最新研究成果，分别计算出火灾中达到危险状态的时间和整个疏散过程所需的时间，通过对比这两个时间，来确定火灾危险性的大小。这种方法概念清晰，简单易行，能在一定程度上对实际建筑物的火灾危险性进行评估，也可用于对火灾的安全工程设计评价和安全咨询。     

SPME/GC-MS在对火场残留物分析中的应用及其数据分析

本文利用固相微萃取(SPME)的高富集性和气相色谱-质谱(GC-MS)的精确性,采用SPME/GC-MS方法对模拟纵火现场中的常见火灾残留物进行分析,并通过比较其特性化合物,很大程度上提高了判断的准确性.利用二甲基苯、三甲基苯、四甲基苯及甲基萘类化合物各自异构体的特征比值,可以很好地减少分析过程中背景干扰.通过向量夹角法进行相似度分析可以帮助判断干扰物的影响.     

Reaction hazard and mechanism study of H2O2 oxidation of 2-butanol to methyl ethyl ketone using DSC,Phi-TEC II and GC-MS

Methyl ethyl ketone (MEK) oxidation via H₂O₂ with tungsten-based polyoxometalate catalysts has gained much attention with an ever-growing body of knowledge focusing on the development of environmentally benign processes in chemical industry. In this study, two calorimetry techniques, differential scanning calorimetry (DSC) and Phi-TEC II adiabatic calorimetry, were employed to analyze the thermal hazards associated with the 2-butanol oxidation reaction system. Hydrogen peroxide was the oxidant and a tungsten-based polyoxometalate as the catalyst. Gas chromatography-mass spectrometry was used for identification of the organic products. Important thermal kinetic data were obtained including “onset” temperature, heat of reaction, adiabatic temperature rise and self-heat rate. From DSC results, three exothermic peaks were detected with a total heat generation of approximately 1.26 kJ/g sufficiently to induce a thermal runaway. Possible reaction pathway for three stages were proposed based on both DSC and GC-MS results. One exotherm was detected by Phi-TEC II calorimeter and the pressure versus temperature profile together with the DSC and GC-MS data demonstrate the complexity of 2-butanol reaction system under both thermal screening and adiabatic conditions.     

原油油气职业卫生标准研究

我国目前尚未制订原油油气卫生标准,多数引用溶剂汽油卫生标准,研究表明原油油气毒性较溶剂汽油大,为保障油运装卸作业人员的健康,科学地监测与控制油气污染,确定合理的作业环境,制订原油油气卫生标准是十分必要的。该研究通过色-质联用分析,表明原油蒸气成份大多为C9以下烷烃、环烷烃及少量的芳香烃。采用大、小鼠为对象的急性毒性实验研究,获得大庆、胜利、渤海3种原油油气的LC50分别为49.54g/m3、77.54g/m3、417.50g/m3;亚慢性毒性实验研究表明,原油油气对动物神经系统的影响较为突出。现场劳动卫生学调查统计表明油轮、油码头作业人员,除了在装船、装罐作业状态下受到较大油气浓度危害外,大部分时间处于100mg/m3以下油气浓度环境,但长期从事油运装卸作业,表现出一定的健康异常,其主要症状是神衰症候群发生率明显增高,植物神经功能障碍,血象异常,其次为心率、心电图的改变等。根据上述研究结果,该研究认为原油装卸贮运作业场所原油油气时间加权平均容许浓度确定为100mg/m3(以总烃计)较为适宜。     

多功能闸门应急处理难溶性液态有机泄漏物性能

为有效应对难溶于水的液态有机物泄漏事故,设计了可快速拦截、分离和收集此类泄漏物的多功能闸门装置。研究了该闸门对轻质(密度小于1.0×103kg/m3)和重质(密度大于1.0×103kg/m3)难溶性物质的去除效果。结果表明,流速对处理效果有一定影响,但可通过闸门组合减弱其影响;有机物密度是影响该闸门性能的重要因素,密度与水差异越大效果越好。在试验设计的最大流速下:两道闸门对0#柴油和97#汽油总的去除率分别为70.5%和80.2%;单道闸门对二氯甲烷和硝基苯的去除率可分别达到80.9%和80.4%。两道闸门组合对0#柴油和二氯甲烷同时泄漏总的去除率为81.2%。     

Lower explosion limit of the vented gases from Li-ion batteries thermal runaway in high temperature condition

The thermal runaway of lithium-ion battery (or Li-ion battery, LIB) results in scrap of battery and fire, with the toxic and flammable gases generated. In this work, a self-made device was to collect gases from LIB thermal runaway, when the batteries were under different states of charge (SOC), temperatures of the environment and powers of external heating. Three samples of the collected gases were analyzed to get the results of the composition and content by chromatography-mass spectrometry system (GC-MS). The lower explosion limits (LELs) of the gases was tested by FRTA explosion limit instrument. And then the LEL of three analyzed samples whose composition and content were known by GC-MS were calculated via theoretical formulas. The calculated LELs were compared with those of the instrument test. The errors of the two results of three samples are 2.1%, 1.9%, and 0.4%. The Le Chatelier Formula and empirical formula provide a way to evaluate the LEL of the battery runaway gas more quickly.     

航空压力环境对锂离子电池热解气体爆炸极限影响*

针对航空锂离子电池热失控释放气体安全性研究不足的问题,采用气体拉曼光谱技术、气相色谱仪(Gas Chromatography,GC)和质谱(Mass Spectroscopy,MS)耦合来探究压力和荷电状态(State of Charge,SOC)对锂离子电池早期故障气体类型、气体动态演变及气体潜在危险性等特征的影响规律,同时综合考虑压力、电压和电池温度等多种因素分析锂离子电池热失控危害。研究结果表明:电池SOC越高且环境压力越低,电池越早触发热失控,爆炸极限越宽,其中30 kPa下100%SOC电池热解气体爆炸极限为8.01%~53.35%;SOC和环境压力越高,电池热失控越危险,释放的气体体积越多;CO,CO2,PF3,C2H4及电解液（C3H6O2、C3H6O3、C4H8O2）等气体可作为航空锂离子电池早期故障诊断特征。研究结果对保障锂离子电池在航空领域的安全运输及应用具有重要意义。     

车用乙醇汽油静电起电特性试验研究

为研究乙醇汽油使用过程中存在的静电风险及带电变化规律,基于自主研发的油品电荷密度表,试验研究了乙醇含量对管输汽油静电带电规律的影响,获得乙醇体积含量0~5%的管输油品静电数据;对油库内乙醇汽油装车作业及加油站加油作业乙醇汽油静电起电特性进行了试验研究。研究结果表明:随着乙醇含量的增加,油品静电呈现先增大后减小的趋势;乙醇体积含量在0.5%~1%时,油品静电起电量最高可达到-77.2 μC/m3,为此需注意乙醇汽油调配过程中可能存在的静电风险;高电导率的车用乙醇汽油在加油作业时,油品静电起电量较低。     

Gasoline prices and traffic crashes in alabama, 1999-2009

Objective: The price of gasoline has been found to be negatively associated with traffic crashes in a limited number of studies. However, most of the studies have focused either on fatal crashes only or on all crashes but measured over a very short time period. In this study, we examine gasoline price effects on all traffic crashes by demographic groups in the state of Alabama from 1999 to 2009. Methods: Using negative binomial regression techniques to examine monthly data from 1999 to 2009 in the state of Alabama, we estimate the effects of changes in gasoline price on changes in automobile crashes. We also examine how these effects differ by age group (16-20, 21-25, 26-30, 31-64, and 65+), gender (male and female), and race/ethnicity (non-Hispanic white, non-Hispanic black, and Hispanic). Results: The results show that gasoline prices have both short-term and long-term effects on reducing total traffic crashes and crashes of each age, gender, and race/ethnicity group (except Hispanic due to data limitations). The short-term and long-term effects are not statistically different for each individual demographic group. Gasoline prices have a stronger effect in reducing crashes involving drivers aged 16 to 20 than crashes involving drivers aged 31 to 64 and 65+ in the short term; the effects, however, are not statistically different across other demographic groups. Conclusions: Although gasoline price increases are not favored, our findings show that gasoline price increases (or decreases) are associated with reductions (or increases) in the incidence of traffic crashes. If gasoline prices had remained at the 1999 level of $1.41 from 1999 to 2009, applying the estimated elasticities would result in a predicted increase in total crashes of 169,492 (or 11.3%) from the actual number of crashes. If decision makers wish to reduce traffic crashes, increasing gasoline taxes is a possible option-however, doing so would increase travel costs and lead to equity concerns. These findings may help to shape transportation safety planning and policy making.     

多分支管道油气爆炸特性大涡模拟

为了研究油库常见的分支结构空间内发生油气爆炸时火焰和压力的传播特性,建立了基于WALE湍流模型及Zimont预混火焰模型的油气爆炸模型;模拟了6种不同分支管道结构空间内汽油/空气混合物爆炸发生发展过程;研究了分支管道数量及相对设置位置对爆炸超压的影响规律,以及分支管道对火焰传播形态和速度的影响规律;模拟结果与前人相关实验规律进行对比。研究结果表明:分支管道对汽油/空气混合气预混爆炸具有明显的强化激励作用;火焰锋面传播经过分支管道时,经历规则—褶皱—规则的变化过程;主管道内火焰传播速度,在分支管道对流场的突扩作用和湍流作用的共同影响下呈震荡变化的规律。