有毒物质Hormesis效应的识别与评价

有毒物质Hormesis效应对传统的毒理学模型提出了挑战.在低剂量条件下单纯的效应增强并不一定是Hormesis效应,可能由效应的某种波动或试验误差引起.对有毒物质Hormesis效应特征、发生的低剂量范围及其识别与评价方法进行了综述,并以低剂量镉对蚯蚓体内谷胱甘肽过氧化物酶(GSH - PX)活性影响为例,建立了Hormesis效应及其定量评价方法.结果表明,二次函数拟合模型为y=0.3994- 1.4472X2+ 1.707X,刺激效应强度为45.34％.     

谁敢不念液化气安全使用经

前几年要说液化气,还跟大多数居民无关,现在液化气越来越成为居民不可缺少的“三宝”——水、气、电之一.液化气在给城乡居民生活带来极大方便的同时,也带来一种潜在的危险.甚至个别家庭由于液化气火灾爆炸事故,造成家毁人亡、重大经济损失、留下终身残疾和难以言状的痛苦.据不完全统计,我市已发生近20起液化气火灾爆炸事故,多人严重烧伤.十字街有一户液化气泄漏,女主人和孩子回家后不懂正确处理,去拉照明灯开关,由于开关火星引起室内液化气爆燃,母子俩被大面积烧伤.某市一锅炉     

浅谈液化气换气点的安全隐患

液化气换气点为广大居民集中提供瓶装液化石油气的更换服务,其周边环境多较复杂,潜在安全隐患可能造成较严重的生命财产损伤.本文实地考察液化气换气点运营情况,对液化气换气点的周边环境、设备设施、换气操作、运营管理等方面进行隐患分析,旨在对规范液化气换气点安全管理,规避液化气毒害、火灾及爆炸事故提供参考.     

有毒物质毒性效应数据库在化学灾害性事故中的作用

介绍了国内外主要的有毒物质毒性效应数据库,其中包括英国DESCNET系统,美国化学信息网(CSIN)和化学物质毒性效应登记(RTECS),联合国环境规划署的潜在有毒化学品国际登记中心(IRPTC),匈牙利生物活性天然产物数据库(BNPD),中国国家有毒化学品基础数据库(NRPTC),中国防化研究院的化学毒物数据库(CTDB),化工部化工毒物咨询中心(CTSIS),中国预防医学科学院有毒化学品资料数据检索和咨询系统,中科院生态环境研究中心三致效应数据库。评述了各数据库的数据源、数据覆盖范围、数据的运行环境和检索方式等。     

石油液化气储配站火灾爆炸危险分析与事故后果评价

对石油液化气储配站火灾爆炸危险因素从危险物质、设计与施工、安全管理等方面进行分析,并进行了重大危险源辨识,对石油液化气泄漏引发蒸气云爆炸事故进行后果评价,并提出了相应的安全对策.     

厨师的职业性危害

据监测,公共食堂作业环境中,粉尘、一氧化碳、二氧化硫的浓度分别为9.68%、29.03%、1.61%,超过国家卫生标准.这些有害物质,主要来自燃料的燃烧.粉尘以液化气为最高,一氧化碳和二氧化硫以焦煤为最高.烹调时产生的油烟对健康的危害也不容忽视.油烟的主要有害物质有:醛、酮、烃、脂肪酸、芳香族化合物等.油烟可直接刺激呼吸系统,引起肺水肿及集体的损伤,使肺功能下降,导致慢性支气管炎发病率的增加.动物实验表明,厨房污染物对体液免疫有抑制作用.由此可见,公共食堂应列入有毒有害作业场所,纳入劳动卫生工作范围.     

液化气钢瓶之殇,谁之过?

7月12日,上海市奉贤区青村镇西街2弄1号居民楼三楼液化气钢瓶泄漏发生爆炸后燃烧.事故造成2名居民死亡,4名居民不同程度受伤. 事实上,类似的液化气钢瓶爆炸事故并不鲜见.记者搜索"液化气钢瓶事故",网页上出现了大量此类事故的报道:"江苏一车库发生液化气钢瓶爆燃事故一老人受伤" "山西一民房爆炸原因为液化气瓶气体泄漏引发...     

厨师的职业性危害

据监测,饭店食堂作业环境中,粉尘、一氧化碳、一氧化硫的浓度分别为9.68%、29.03%、1.61%,超过国家卫生标准.这些有害物质,主要来自燃料的燃烧.粉尘以液化气为最高,一氧化碳和二氧化硫以焦煤为最高.烹调时产生的油烟对健康的危害也不容忽视.油烟的主要有害物质有:醛、酮、烃、脂肪酸、芳香族化合物等.油烟可直接刺激呼吸系统,引起肺水肿及机体的损伤,使肺功能下降,导致慢性支气管炎发病率的增加.动物实验表明,厨房污染物对体液免疫有抑制作用.由此可见,饭店食堂应列入有毒有害作业场所,纳入劳动卫生工作范围.     

浅谈民用液化气钢瓶安全管理与隐患防范

液化气钢瓶属高压薄壁容器,国家不仅将盛装液化气的钢瓶列为易燃易爆危险品管理范畴,而且对液化气钢瓶的使用期限、质量检测,以及储存、运输、搬运等都有严格的规定。一般来说,由企业自行承担的居民用户生活燃气供应,是相对独立于外部社会的燃料供应体系,液化气钢瓶处于高度循环使用状态。因此,大企业民用液化气钢瓶的安全管理与隐患防范,必须放到重要位置抓实抓好。     

液化气诱发心脏病

长期燃烧液化气造成的室内空气污染,有诱发心脏病的危险。 在燃烧液化气的室内空气中,平均一氧化碳浓度为18％,而经常在燃烧液化气的室内居住者的呼气中,一氧化碳浓度可达10～30％。液化气燃烧时,如果室内氧气不足,液化气得不到充分燃烧,会导致较多的一氧化碳散入室内。由于吸入的一氧化碳与体内血红蛋白结合,致使血液携氧量减少,     

消防水幕对有害气体阻隔效果的试验研究

为研究消防水幕对有害气体的阻隔效果,通过大型和小型2种尺度的试验,测定大型真实水幕对液化石油气的阻隔效果,并建立实验室小尺寸水幕模型,测定水幕对液化石油气、氯气、氨气、二氧化碳等气体的阻隔效果。此外,在小尺寸模型中,添加特定化学药剂测定水幕对氨气和氯气的阻隔效果。结果表明:消防水幕可以有效地阻隔和稀释有害气体;在水源中添加特定的化学药剂,可以有效地提高水幕阻隔和稀释的效果,阻隔效率达到90%以上。为消防部队今后处置化学事故提供切实可靠的数据支撑。     

液化石油气BLEVE事故研究

为了减小液化石油气沸腾液体扩展蒸汽云爆炸事故后果,采用ALOHA软件对液化石油气储罐泄漏事故进行研究,基于液化石油气泄漏量、空气湿度、风速、储存温度等爆炸事故后果影响因素进行数值模拟。研究结果表明:液化石油气泄漏量越大,沸腾液体扩展蒸汽云爆炸事故产生的火球直径越大,燃烧时间或热辐射时间越长,且造成的危害范围越大,事故后果越严重;随着空气湿度增加,事故影响的范围逐渐减小,事故后果相对减小;随着液化石油气储存温度增加,事故影响范围逐渐减小;风速对于事故影响范围无影响;空气湿度、储存温度及风速对火球直径及火球燃烧时间无影响。     

液化石油气爆炸范围及爆炸力的测定

液化石油气、瓦斯等可燃气体的爆炸防治是一个非常迫切需要解决的问题.利用自制可燃气体爆炸箱来模拟可燃气体爆炸,并通过光干涉甲烷测定仪来测定混合气体爆炸时的甲烷百分含量,再推算出液化石油气的爆炸范围和计算爆炸力.     

Numerical study on the initial expansion of two-phase cloud from an instantaneous release

In industries some dangerous liquefied gases may accidentally release and it may form a flammable or toxic mixture after mixing with air. One tool that is being developed in industry for two-phase cloud dispersion modeling is computational fluid dynamics (CFD). In this paper, the dispersion processes of different dangerous materials including liquefied chlorine, liquefied ammonia and liquefied petroleum gas were simulated in the same condition to analyze the characteristics of the initial expansion processes by CFD tool. The heat and mass transfer between droplets and the vapor after an instantaneous release event was calculated by using the Eulerian–Lagrangian method. The results from a number of 3-D CFD based studies were compared with the available small-scale experimental results. The results show that the present model and numerical simulation are reliable.     

液化石油气钢瓶长径比研究

分析钢瓶的长度和直径之比(长径比)对容积变形率的影响,在材料相同的条件下,长径比大的气瓶的容积变形率的要求也相应提高。笔者分别从钢瓶的边界效应、冲压工艺、制造经济性3个方面探讨了液化石油气钢瓶的合适长径比,并综合提出了液化石油气钢瓶的长径比的适宜范围为0.8～1.6。     

Estimation of safety distances in the vicinity of fuel gas pipelines

In this paper, safety distances around pipelines transmitting liquefied petroleum gas and pressurized natural gas are determined considering the possible outcomes of an accidental event associated with fuel gas release from pressurized transmission systems. Possible outcomes of an accidental fuel gas release were determined by performing the Event Tree Analysis approach. Safety distances were computed for two pipeline transmission systems of pressurized natural gas and liquefied petroleum gas existing in Greece using real data given by Greek Refineries and the Greek Public Gas Enterprise. The software packages chetah and breeze were used for thermochemical mixture properties estimation and quantitative consequence assessment, respectively. Safety distance determination was performed considering jet fire and gas dispersion to the lower flammable limit as the worst-case scenarios corresponding to immediate and delayed cloud ignition. The results showed that the jet fire scenario should be considered as the limiter for safety distances determination in the vicinity of natural and petroleum gas pipelines. Based on this conclusion, the obtained results were further treated to yield functional diagrams for prompt safety distance estimation. In addition, qualitative conclusions were made regarding the effect of atmospheric conditions on possible events. Thus, wind velocity was found to dominate during a jet fire event suppressing the thermal radiation effect, whereas gas dispersion was found to be affected mainly by solar radiation that favors the faster dissolution of fuel gas below the lower flammable limit.     

不同物质组合摩擦火花引燃特性的研究

在本研究中,对碳钢、铍青铜和铜镍锰合金等三种金属与砂轮和45号钢轮摩擦时产生火花的能力和引燃能力作了对比实验。用于实验的可燃混合气为液化石油气/空气和氢/空气。实验表明,碳钢和砂轮摩擦产生的火花最强烈,但仍很难引燃液化石油气/空气混合气;铍青铜与砂轮摩擦时几乎看不到火花,铜镍锰合金在同样条件下产生火花的几率销大。在摩擦时间较长的条件下,两者均能引燃极易爆炸的氢/空气混合气,但爆炸却并不是在火花出现时立即发生的。可以推断:在上述条件下,摩擦造成的炽热表面是引燃的主要原因,而材料的引燃能力的强弱,不能只以是否产生火花为判断基准。     

液化石油气罐区危险性的定量评价

液化石油气罐区的主要危险是贮罐区发生火灾、爆炸事故。运用数学模型对液化石油气贮罐的危险性进行定量化评价，估算其爆炸事故的严重程度、波及范围、影响程度等     

Estimation of displacement losses from storage containers using a simple method

Filling losses in tanks due to the expansion of the liquid into the tank and the vapors that are forced out of the tank are generally called displacement losses. Restrictions on vaporization loss of petroleum products give added emphasis to the accurate prediction of vapor pressure and hydrocarbon losses for petroleum products. In this work, firstly, a simple-to-use correlation is developed to estimate the true vapor pressure of liquefied petroleum gas (LPG) and natural gasoline as a function of Reid Vapor pressure (RVP) and temperature as well as the vapor pressure of different mixtures of propane and butane are correlated as a function of ambient air temperature and propane volume percent. Secondly, the filling losses from storage containers are estimated in percentage of liquid pumped in tanks as a function of working pressure and vapor pressure at liquid temperature. The study showed the proposed method to be in good agreement with the available reliable data in the literature. The average absolute deviation between reported data and the proposed correlation is less than 2%. The proposed simple-to-use approach can be of significant practical value for the process engineers and scientists to have a quick check on the prediction of the displacement losses from storage containers as well as for rapid estimation of vapor pressure of LPG and natural gasoline.     

低压液化气体钢瓶＂满液＂爆炸压力变化分析

本文对低压液化气体钢瓶“满液”爆炸的特征及内部压力变化了进行了理论分析和举例计算,并就如何安全使用液化气体钢瓶提出了一些合理化建议,希望能对气瓶的安全使用起到一定的警示作用。