危险气体泄漏扩散的实验方法研究

综述了研究危险气体事故泄漏扩散的3种实验方法,即全规模大型现场实验、实验室模拟和小型现场实验,详细讨论该3种试验方法在实施和应用中的优缺点。对小型现场实验的无量纲长度、速度、时间、大气稳定度、大气湍流、液滴的尺寸分布和沉降、源动量通量比例等重要参数的确定方法重点进行分析和阐述。小型试验法特别适用于模拟化学性质活泼的危险气体的泄漏扩散研究,可为安全评价、应急救援提供有价值的参考数据。     

深埋地铁岛式站点火灾模型实验研究(3)--站台火灾

随着我国城市轨道交通的发展，地铁深埋站点将越来越多。深埋地铁站点及区间隧道消防安全是深埋车站设计过程中需要加以考虑的科学问题，本文主要介绍深埋地铁车站站台火灾模型实验过程，分析火源功率为205MW的站台火灾过程中，烟气在站台内的蔓延过程、站台内气流组织情况、站台烟气向邻近空间蔓延的特点；探讨深埋车站烟气蔓延和控制规律，为深埋站点的火灾安全设计提供参考。     

行人和疏散动力学研究现状及进展

行人和疏散动力学的研究在步行设施的设计,人群的安全疏散,城市规划及计算机疏散软件开发等方面具有重要意义.对国内外的研究现状进行了评述,对研究内容、研究方法进行了分类,对研究成果及应用进行了总结,同时指出了目前研究中存在的问题,对这一领域中研究发展提出了建议.     

Linking field experiments to long-term simulation of impacts of nitrogen deposition on heathlands and moorlands

The results from three long-term field manipulation studies of the impacts of increased nitrogen deposition (0–120 kg N ha^–1 yr^–1) on lowland and upland heathlands in the UK were compared, to test if common responses are observed. Consistent increases in Calluna foliar N content and decreases in litter C:N ratios were found across all sites, while increases in N leaching were not observed at any site over the range 0–80 kg ha^–1 yr^–1. However, the response of Calluna biomass did vary between sites, possibly reflecting site differences in nutrient status and management histories. Five versions of a simulation model of heathland responses to N were developed, each reflecting different assumptions about the fate and turnover of soil N. Model outputs supported the deduction from mass balance calculations at two of the field sites that N additions have resulted in an increase in immobilisation; the latter was needed to prevent the model overestimating measured N leaching. However, this version of the model significantly underestimated Calluna biomass. Model versions, which included uptake of organic N by Callunaand re-mobilisation of N from the soil organic store provided some improvement in the fit between modelled and field biomass data, but re-mobilisation also led to an overestimation of N leaching. Quantification of these processes and their response to increased N deposition are therefore critical to interpreting experimental data and predicting the long-term impacts of atmospheric deposition on heathlands and moorlands.     

Feature of Dust Particles in the Spring Free Troposphere over Dunhuang in Northwestern China: Electron Microscopic Experiments on Individual Particles Collected with a Balloon-borne Impactor

Free tropospheric aerosol particles were collected using a balloon-borne particle impactor in August of 2002 and March of 2003 at Dunhuang in northwestern China (40°00′N, 94°30′E), and the morphology and elemental composition of the aerosol particles were analyzed in order to understand the mixing state of coarse dust particles (diameter >1 μm) over the desert areas in the Asian continent in spring. Electron microscopic experiments on the particles revealed that dust particles were major constituents of coarse mode particles in the free troposphere over the Taklamakan Desert in spring and summer. Si-rich or Ca-rich particles are major components of dust particles collected in the free troposphere over dunhuang and the values of [number of Ca-rich particles]/[number of Si-rich particles] differs markedly between spring and summer, being about 0.3 in the spring of 2003 and about 1.0 in the summer of 2002 at heights 3–5 km above sea level. It is likely that the condition of the ground surface and the strength of vertical mixing in source areas of Asian dust are potential factors causing the difference in the chemical types of dust particles. Comparison of the elemental compositions of these particles with those of particles collected over Japan strongly suggests that these particles were chemically modified during their long-range transport in the free troposphere. Analysis of wind systems shows that both the predominating westerly wind in the free troposphere and the surface wind strongly controlled by the geographical structure of the Tarim Basin are important in the long-range transport of KOSA particles originating in the Taklamakan Desert.     

预膜过滤技术在采油污水处理中的应用

详细介绍了新开发的FDF300型过滤工艺,并通过试验验证了自行研制的新型GM助剂在FDF型过滤器中应用的工艺条件,考察了助剂用量、型号、预膜时间以及空气反吹脱渣时间、反吹压力等因素对过滤效果的影响。结果表明,选用150gGM3助剂,预膜时间约20 min,空气反吹脱渣时间5 min,反吹压力0.35 MPa等工艺条件,可以获得理想的过滤效果,解决了长期困扰油田采油污水含油量和机械杂质不达标的难题。     

焦化汽油储罐腐蚀模拟实验研究

通过企业现场调研，对焦化汽油储罐腐蚀进行了实验模拟研究，对实验数据结果进行了分析。在实验研究的基础上，结合若干由于腐蚀引起的事故案例和事故机理的分析，对焦化汽油储罐自燃事故的主要原因及发生条件进行了剖析，总结并提出了相应的预防控制措施。实验结果可作焦化汽油储罐安全设计和焦化汽油工艺改进的重要参考。     

环境监测中氯化氢测定的分析方法试验

针对国家标准《HJ/T27-1999》与《空气和废气监测分析方法》的2种氯化氢测定方法中氢化钾用不同介质进行稀释，和显色时间及试剂加入量的区别进行正交试验，得出结果。     

测定废水重金属样品的高压蒸汽消解方法

本文采用正交实验方法，用自己研制的“自控式高压蒸汽消解器”，详细研究了测定废水重金属，样品的最佳消解条件，并用于实际废水样的消解和重金属的测定，准确度和精密度均优于传统的敞口消解法，并具有试剂用量少、时间短、不受污染、操作简单，批处理样品量大等优点，可作为测定废水中重金属，样品的常规消解方法。     

冷原子荧光法测定地面水和土壤中的痕量总汞

本文推导了汞元素冷原子荧光测试的理论公式，着重研究了载气种类；载气流速；工作电压；水蒸气；介质酸度；还原剂用量等１０项因素对测定结果准确度的影响，确定了最佳实验条件，提出了地面水和土壤中痕量总汞的测试方法。同时分析了汞元素冷原子荧光法的系统误差和消除或减少系统误差的方法。