聚合氯化铝与聚磷硫酸铁絮凝除藻比较研究

针对武汉市莲花湖湖水,采用聚合氯化铝(PAC)和聚磷硫酸铁(PPFS)进行絮凝实验,比较了两种无机絮凝剂的絮凝效果及原水处理前后藻类群落变化。主要结论如下:①PPFS与PAC的最佳投加量分别为1.5mg/L、2.0mg/L;②PPFS在去除藻类细胞、浊度和色度方面均优于PAC,当PPFS投加过量时,因水体中Fe3+过量分布,使水样色度去除率下降;③PPFS絮凝处理微囊藻为主体的水华原水时,其效果比PAC更好。本文研究后表明:PPFS是一种新型高效絮凝剂,其絮凝性能明显优于PAC,当水体以微型藻类为主时,可使用PPFS以替代PAC,能提高絮凝效果。     

人因可靠性分析方法

回顾了人因可靠性分析 (HRA)的发展历史 ;汇总了近几十年来的各种人因可靠性分析方法 ;详细介绍了人的失误率预测技术 (THERP)、人的认知可靠性模型 (HCR)、成功似然指数法 (SL IM)的背景、使用步骤、特性等 ;分析了 THERP+ HCR的优势 ,并给出了一个应用实例。最后 ,指出了目前 HRA方法的不足并预测了 HRA的发展趋势     

新型气体灭火剂开发技术研究

为了提高哈龙替代灭火剂的灭火性能,减少其对环境的不利影响,必须加快开发新一代气体灭火剂的步伐。提出了理想哈龙替代灭火剂的筛选标准和12种主要性能的分级方法,探讨了筛选过程的设计策略和选择筛选试验方法的基本原则,通过对典型气体灭火剂主要性能的对比,揭示了气体灭火剂的发展历程。剖析了气体灭火剂的灭火浓度、大气寿命、分散性、灭火剂及其分解和燃烧产物的毒性等重要性能的筛选技术发展现状和存在问题。认为应尽快建立并完善气体灭火剂的各项主要性能筛选试验方法,构建完整的气体灭火剂替代品性质数据库,在此基础上形成科学的性能预测体系,以便更好地从大量备选化学物质中找出综合性能优异、适合面广的新一代气体灭火剂系列品种。     

回采工作面涌水事故的处理

掘进18m长的疏水巷道,使透人31404回采面的涌水流人31402回采面的采空区,降低了水压,保证了该回采面的正常生产,并减少了下分层开采时突然涌水的危险,增加了安全性与可靠性.     

Approach for the use of MSW settlement predictions in the assessment of landfill capacity based on reliability analysis

In the analysis and design of municipal solid waste (MSW) landfills, there are many uncertainties associated with the properties of MSW during and after MSW placement. Several studies are performed involving different laboratory and field tests to understand the complex behavior and properties of MSW, and based on these studies, different models are proposed for the analysis of time dependent settlement response of MSW. For the analysis of MSW settlement, it is very important to account for the variability of model parameters that reflect different processes such as primary compression under loading, mechanical creep and biodegradation. In this paper, regression equations based on response surface method (RSM) are used to represent the complex behavior of MSW using a newly developed constitutive model. An approach to assess landfill capacities and develop landfill closure plans based on prediction of landfill settlements is proposed. The variability associated with model parameters relating to primary compression, mechanical creep and biodegradation are used to examine their influence on MSW settlement using reliability analysis framework and influence of various parameters on the settlement of MSW are estimated through sensitivity analysis.     

建筑结构安全控制机制

就当前人们关注的建筑结构安全问题,结合系统失效规律,提出对建筑结构全过程实施可靠性鉴定,从而有效地控制了建筑结构倒塌事故。     

供应链系统可靠性分析

供应链是由物料获取并加工成中间件或成品 ,再将成品送到顾客手中的一些企业和部门构成的网络 ,它包括供应商 (包括供应商的供应商等 )、制造商、配送中心、零售商、最终用户等多个多级实体。除了性能以外 ,其可靠性已经成为供应链管理研究的重点。鉴于供应链中存在的诸多层次与环节致使供应链的可靠性分析十分复杂 ,为了简便起见 ,笔者认为 ,必须从单级供应链可靠性分析出发 ,再进行基于马尔可夫过程的多级供应链可靠性分析 ,最后根据分析结果 ,提出一些提高供应链可靠性的措施。该方法对供应链系统可靠性分析具有实用价值 ,其关键环节是将串联结构改变为并联结构来实现。     

Reliability data acquisition and evaluation in process plants

Based on the practical experience of assessing reliability data in two plants of the explosives industry, the organization and scope of the data collection, the component delimitation, the procedures of quality assurance and the data evaluation for their final use in PSA studies are presented. An example is given for the type of detection and repair, etc. The mathematical background for evaluating observed component lifetimes is discussed. Both frequentist and Bayesian methods are addressed. The resulting failure rate distributions and their approximations by log-normal distributions for several key components are presented. They were obtained using a Bayesian approach with a non-informative prior. Remarks on uncertainty, their treatment and a proposal for transferring data to plants other than the ones investigated conclude the presentation.     

Mechanical properties of Municipal Solid Waste by SDMT

In the paper the results of a geotechnical investigation carried on Municipal Solid Waste (MSW) materials retrieved from the “Cozzo Vuturo” landfill in the Enna area (Sicily, Italy) are reported and analyzed. Mechanical properties were determined both by in situ and laboratory large-scale one dimensional compression tests.While among in situ tests, Dilatomer Marchetti Tests (DMT) is used widely in measuring soil properties, the adoption of the DMT for the measurements of MSW properties has not often been documented in literature. To validate its applicability for the estimation of MSW properties, a comparison between the seismic dilatometer (SDMT) results and the waste properties evaluated by laboratory tests was carried out.Parameters for “fresh” and “degraded waste” have been evaluated. These preliminary results seems to be promising as concerns the assessment of the friction angle of waste and the evaluation of the S-wave in terms of shear wave velocity. Further studies are certainly required to obtain more representative values of the elastic parameters according to the SDMT measurements.     

Reliability analysis of pedestrian safety crossing in urban traffic environment

This paper describes the pedestrian safety crossing behaviour at signalized crosswalks in an urban traffic environment based on human reliability analysis. In our research, pedestrians’ waiting durations are modelled by a non-parametric and two parametric reliability models that recognize the effects of covariates. The covariates include pedestrian personal characteristics and urban traffic conditions in order to reflect the effects of human factors and internal environment comprehensively. The results indicate that most pedestrians show distinct time-dependent reliability but a few pedestrians are too impatient to wait for the lights changes.