工厂供配电系统运行和维护的安全技术要求

工厂供配电系统触电事故以及电气火灾和爆炸事故时有发生,不但影响生产,还造成巨大的经济损失甚至人员伤亡。介绍了工厂供配电系统运行和维护的安全要求,主要包括变配电所的运行和维护、电力线路的运行和维护及其他安全管理要求。     

污水处理场日常检维修作业的HSE管理

对污水处理场日常检维修项目进行分类，分析不同类型检维修作业工作危害，将不同类型的HSE施工作业指导书结合到进装置作业施工作业票的签批中，规范执行风险评价过程，并落实风险削减措施，以深化日常小型检维修作业的HSE管理。     

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.     

Application of a predictive safety model in a combustion testing environment

A predictive safety model for accident prevention and system failure, called Continuous Hazard Tracking and Failure Prediction Methodology, is applied at the Marshall Space Flight Center's promoted combustion test chamber. It combines the underlying principles of work sampling, control charts, and multivariate analysis. The sampling is performed to observe the occurrence of conditions which may be becoming hazardous in a given system. These building blocks of hazards, which we have called dendritics, could result in an accident, system malfunction, or unacceptable risk conditions. The data collected is plotted to generate the appropriate control chart, which depends on the characteristics of the given system and the protection desired. Based on the pattern of the control chart, a system ‘under control’ is not disturbed whereas a system ‘out of control’ is investigated for potential conditions becoming hazardous. Then appropriate steps are taken to eliminate or control these conditions in order to maintain a desired safety status of the system. The continuously running characteristic of this model allows for the verification that the corrective measures taken to ameliorate the ‘out of control’ conditions were satisfactory or whether more proactive action is required. The results provided by the predictive model were validated with historical safety data.     

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。      

Urban geochemistry: research strategies to assist risk assessment and remediation of brownfield sites in urban areas

Urban geochemical maps of Wolverhampton and Nottingham, based on multielement analysis of surface soils, have shown distribution patterns of “total” metals concentrations relating to past and present industrial and domestic land use and transport systems. Several methods have been used to estimate the solubility and potential bioavailability of metals, their mineral forms and potential risks to urban population groups. These include sequential chemical extraction, soil pore water extraction and analysis, mineralogical analysis by scanning electron microscopy, source apportionment by lead isotope analysis and the development of models to predict metal uptake by homegrown vegetables to provide an estimate of risk from metal consumption and exposure. The results from these research strategies have been integrated with a geographical information system (GIS) to provide data for future land-use planning.     

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.     

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.     

油气管线带压不停输封堵技术在长庆油田的应用

长庆油田通过对管道不停输带压封堵施工技术的探索,在改扩建工程施工中取得了良好的效果。实践证明,与常规施工方法相比可有效缩短维护抢修作业工期20%～30%。它在油气田风险管理、事故预防、环境污染治理方面是积极安全有效的。