城市煤气网管系统的安全维护及运行

煤气作为一种二次能源,是城市中使用的主要能源之一.燃气行业的生产、输送、使用过程,从某种角度来讲是高危的作业过程.煤气网管系统的施工和维护过程中充满了种种困难和危险,造成了许多重大损失,其主要原因是缺乏有效的组织引导和规范的安全措施.本文着重分析了煤气网管系统发生泄露事故的原因,提出了煤气网管系统的运行和维护过程中应当遵循的安全事项和采取的安全措施,为煤气网管系统的运行和维护工作提供了理论依据.     

国有重点煤矿企业安全科技人才现状研究

依据对我国国有重点煤矿企业抽样调查的结果,着重对国有重点煤矿企业安全科技人才的总量、密度、结构、流失等进行了系统的分析,并与美国煤炭行业的人才状况进行了比较分析。笔者在此基础上,给出了国有重点煤矿企业安全科技人才现状的基本评价,国有重点煤矿企业安全科技人才断层已经出现,安全科技人才总量严重不足,人才的问题已经开始制约煤炭行业的发展,尤其是严重制约着煤炭行业建立安全生产长效机制;对进一步加强和优化国有重点煤矿企业安全科技人才队伍建设提供了可靠的依据,具有重要指导意义。     

建筑物火灾时人员疏散时间模型研究

在建筑物火灾中,人员安全疏散与人员的生命安全直接相关.人员能否安全疏散主要取决于疏散到安全区所用时间的长短,人员疏散时间在考虑建筑物结构和人员距离安全区的远近等环境因素的同时,还必须综合考虑处于火灾等紧急情况下人员的自然状况和人员心理及行为特征.本文在组织人员应急疏散演习测量个体疏散时间的基础上,结合影响人员疏散行为和疏散时间的相关因素,采用世界先进统计软件SPSS12 for Windows进行多元线性回归分析,建立人员疏散时间回归模型.该研究技术科学、先进,结果可信.研究结果将充实我国人员疏散心理和行为反应数据库,为建筑防火性能化设计,尤其是设计人员密集建筑提供基础数据和初步的分析.     

人工湿地处理系统的运行管理与维护

人工湿地作为一种新型的处理技术，在水环境保护中具有重要的意义和广阔的应用前最。随着人工湿地处理工程数量的增多，迫切地需要建立科学的管理制度和维护方法，以充分发挥其美化水环境和提升人文环境的双重作用。本文对人工湿地处理系统中水位控制、进出水装置维护、护堤维护、植物管理、气味控制、蚊蝇控制和野生动物管理等方面进行了分析探讨，系统论述了人工湿地处理系统在运行管理和维护中需要考虑的主要事项。对将来建立完善的人工湿地处理系统的管理体系具有一定的借鉴意义。     

广州市I/M计划升级及其在机动车NOx减排中的效果

以广州市为例,系统地讨论了机动车污染控制中的检查维护计划(I/M)。评估了广州市现行的I/M计划的实施情况及存在的问题,针对广州市NO_x污染控制目标,提出了广州市I/M计划升级的技术考虑,并对建议的两种加载I/M计划ASM和IM240进行了初步的费用效果分析。      

基于Gompertz的气象水文装备维修器材消耗量分析与预测

利用由Gompertz曲线推导出的生命周期曲线建立了气象水文装备维修器材消耗-时间模型.计算表明,由Gompertz曲线推导出的生命周期曲线可以较好地反映气象水文装备维修器材消耗量与时间之间的关系,所建模型的预测结果也较好,具有较高的实用性,为探索气象水文装备维修器材消耗规律提供了一种简单有效的科学方法.     

Water Dispatch Model for Middle Route of a South‐to‐North Water Transfer Project in China1

Chang, Jian‐xia, Yi‐min Wang, and Qiang Huang, 2011. Water Dispatch Model for Middle Route of a South‐to‐North Water Transfer Project in China. Journal of the American Water Resources Association (JAWRA) 47(1):70‐80. DOI: 10.1111/j.1752‐1688.2010.00478.x Abstract: The objective of this paper is to present a simulation model to address the water dispatch problem of the south‐to‐north water transfer project for the Middle Route system in China. Reasonable rules and a system network structure are established. This model consists of five modules: (1) a data‐processing module, (2) an initial control module, (3) a multisource simulation dispatch module, (4) a system identification module, and (5) a revision module. Water allocated to each province and city along the route is obtained by simulation, and the long‐term operation results show that water supply reliabilities are significantly improved if the transferred water is jointly dispatched with the local water resources.     

钢箱梁典型病害分析及其检测与维护技术研究

基于对我国钢箱梁桥的钢箱梁病害调查,总结出我国钢箱粱典型病害的类型,分析各种钢箱梁典型病害产生的机理及导致其破坏的原因,提出了钢箱梁病害的日常检测与维护技术.针对钢箱梁的涂装劣化、钢材腐蚀、结构性损伤等病害,给出了日常检测与维护的主要项目,介绍了人工目视检测、超声波检测、磁粉检测及涡流检测等主要的检测方法的工作原理、优...     

Evaluating weather effects on interannual variation in net ecosystem productivity of a coastal temperate forest landscape: A model intercomparison

Forest productivity is strongly affected by seasonal weather patterns and by natural or anthropogenic disturbances. However weather effects on forest productivity are not currently represented in inventory-based models such as CBM-CFS3 used in national forest C accounting programs. To evaluate different approaches to modelling these effects, a model intercomparison was conducted among CBM-CFS3 and four process models (ecosys, CN-CLASS, Can-IBIS and 3PG) over a 2500 ha landscape in the Oyster River (OR) area of British Columbia, Canada. The process models used local weather data to simulate net primary productivity (NPP), net ecosystem productivity (NEP) and net biome productivity (NBP) from 1920 to 2005. Other inputs used by the process and inventory models were generated from soil, land cover and disturbance records. During a period of intense disturbance from 1928 to 1943, simulated NBP diverged considerably among the models. This divergence was attributed to differences among models in the sizes of detrital and humus C stocks in different soil layers to which a uniform set of soil C transformation coefficients was applied during disturbances. After the disturbance period, divergence in modelled NBP among models was much smaller, and attributed mainly to differences in simulated NPP caused by different approaches to modelling weather effects on productivity. In spite of these differences, age-detrended variation in annual NPP and NEP of closed canopy forest stands was negatively correlated with mean daily maximum air temperature during July-September (T_amax) in all process models (R² = 0.4-0.6), indicating that these correlations were robust. The negative correlation between T_amax and NEP was attributed to different processes in different models, which were tested by comparing CO₂ fluxes from these models with those measured by eddy covariance (EC) under contrasting air temperatures (T_a). The general agreement in sensitivity of annual NPP to T_amax among the process models led to the development of a generalized algorithm for weather effects on NPP of coastal temperate coniferous forests for use in inventory-based models such as CBM-CFS3: NPP′ = NPP − 57.1 (T_amax − 18.6), where NPP and NPP′ are the current and temperature-adjusted annual NPP estimates from the inventory-based model, 18.6 is the long-term mean daily maximum air temperature during July-September, and T_amax is the mean value for the current year. Our analysis indicated that the sensitivity of NPP to T_amax was nonlinear, so that this algorithm should not be extrapolated beyond the conditions of this study. However the process-based methodology to estimate weather effects on NPP and NEP developed in this study is widely applicable to other forest types and may be adopted for other inventory based forest carbon cycle models.     

The Impact of Occupational Load Carriage on Carrier Mobility: A Critical Review of the Literature

Military personnel and firefighters are required to carry occupational loads and complete tasks in hostile and unpredictable environments where a lack of mobility may risk lives. This review critically examines the literature investigating the impacts of load carriage on the mobility of these specialist personnel. Several literature databases, reference lists, and subject matter experts were employed to identify relevant studies. Studies meeting the inclusion criteria were critiqued using the Downs and Black protocol. Inter-rater agreement was determined by Cohen’s κ Twelve original research studies, which included male and female participants from military and firefighting occupations, were critiqued (κ = .81). A review of these papers found that as the carried load weight increased, carrier mobility during aerobic tasks (like road marching) and anaerobic tasks (like obstacle course negotiation) decreased. As such, it can be concluded that the load carried by some specialist personnel may increase their occupational risk by reducing their mobility.