秦皇岛市生活垃圾无害化处理现状与展望

通过论述秦皇岛市在城市垃圾收集、压缩、运输、无害化处理方面取得的成功经验,提出环境卫生工作统一领导,分工负责;对不同季节、不同发生主体垃圾成份进行分析,开展垃圾减量化、资源化科学研究;开展垃圾填埋场环境监测工作,防止对水、土壤和大气造成污染,以期把秦皇岛市真正建设成为宜居、宜业、宜游的现代化城市。     

东江流域1959-2009年气候变化及其对径流的影响

依据东江流域21个气象站1959-2009年逐年平均降雨、蒸发、日照、湿度及气温等气象要素序列,选择常用的线性倾向估计及非参数M．K等趋势分析方法,分析了东江流域近50年来气温、降水、蒸发、日照及湿度等气象要素的变化趋势。选择降雨和蒸发两个气候要素两两组合,构成未来气候变动的36种假想情景,运用改进的SCS月模型模拟计算了顺天流域年径流量的变化幅度。结果表明：在过去的50年间,流域降雨量呈不显著增长,而气温则为显著上升,其他气候要素如蒸发、日照及湿度等均呈不同程度减少趋势;关联度分析表明降雨在所有气象要素中与径流的关联度为最大,说明了在东江流域降雨是径流量变化的主要驱动因子;未来流域降雨增加,蒸发减少的气候情景模式下,径流量会有所增加,反之亦然;由降雨变化引起的流域月径流量的增幅较由蒸发变化引起的相应流量的增幅变化大。     

中国农业领域温室气体主要减排措施研究分析

气候变暖已成不争事实,主要是由于人为温室气体(GHG)排放增加所致,为减缓气候变暖趋势,各领域迫切需要采取减排措施;农业是一个重要的GHG排放源,农业领域采取减排措施对于减少我国GHG排放、保护农村生态环境有重要意义。文章在大量阅读前人研究结果的基础上,总结我国农业领域主要的减排管理措施,主要从农业活动、农村生活和生物质能源利用三方面进行阐述,并简要分析各措施的减排效果和存在问题。分析发现,农业活动的水肥管理是农田温室气体减排的研究热点,但由于地域和管理流程上的差异,对措施的减排效果尚存在争议;农村生活中存在巨大的减排潜力,采取恰当的减排措施不但可以减少GHG排放,还可以改善农村生态状况和环境卫生条件;农村生物质能源有很大发展潜力,合理开发利用,可以有效替代化石能源消耗,缓解能源危机,减少GHG排放,保护生态环境。总之,在农业领域采取积极的减排措施,有助于国家效应对气候变化,降低农业源污染和GHG排放,减轻环境压力,转换农业发展模式,加速农业现代化,促进农业生产的可持续发展和社会主义新农村建设。     

化学还原法处理电镀含铬废水的工程应用

用亚硫酸氢钠作还原剂处理含铬电镀废水时,不调节废水pH值会出现暂时定性检测不含六价铬的假象,过一段时间废水中又会出现六价铬,导致排水不达标.针对这一现象进行实验和工程实践,结果表明,不调节pH值增加亚硫酸氢钠的投加量和不增加亚硫酸氢钠投加量而pH值调节到3～4都能使处理后水质稳定,达到排放标准(GB21900-2008...     

Efficacies of roadway safety improvements across functional subclasses of rural two-lane highways

Introduction

Highway crash occurrence is a leading cause of unnatural deaths, and highway agencies continually seek to identify engineering measures to reduce crashes and to assess the efficacy of such measures. Most past studies on the effectiveness of roadway improvements in terms of crash reduction considered all rural two-lane sections as a single category of roads. However, it may be hypothesized that the differences in the mobility and accessibility characteristics that are reflected in (and due to) the different design standards between different functional subclasses in the rural two-lane highway system can lead to differences in efficacies of safety improvements at these subclasses. This paper investigates the efficacy of roadway improvements, in terms of crash reduction, at the various subclasses of rural two-lane highways.

Methods

An empirical analysis of safety performance at each of the three subclasses of rural two-lane highways was carried out using the negative binomial modeling technique. For each subclass, crash prediction models were developed separately for the three levels of crash severity: property-damage only, injury, and fatal/injury. The crash factors that were considered include lane width, shoulder width, pavement surface friction, pavement condition, and horizontal and vertical alignments. After having developed the safety performance functions, the effectiveness (in terms of the extent of crash reduction, for different levels of crash severity) of highway safety enhancements at each highway subclass were determined using the theoretical concepts established in past literature. These enhancements include widening lanes, widening shoulders, enhancing pavement surface friction, and improving the vertical or horizontal alignment.

Results and Conclusion

The study found that there is empirical evidence to justify the decomposition of the family of rural two-lane roads into its constituent subclasses for purposes of analyzing the effectiveness of safety enhancement projects and thus to avoid underestimation or overestimation of benefits of safety improvements at this class of highways.     

Risk reduction concept to provide design criteria for Emergency Systems for onshore LNG plants

The functional safety requirement is widely applied in the process plant industry in accordance with the international standards, such as IEC and ISA. The requirement is defined as safety integrity level (SIL) based on the risk reduction concept for protection layers, from original process risk to tolerable risk level. Although the standards specify both, the Prevention System and the Emergency System, as level of protection layers, the standards specify in detail only the use of the Prevention System (i.e., Safety Instrumented System (SIS)). The safety integrity level is not commonly allocated to the Emergency System (e.g., Fire and Gas System, Emergency Shutdown System and Emergency Depressuring System). This is because the required risk reduction can be normally achieved by only the Prevention System (i.e., SIS and Pressure Safety Valve (PSV)). Further, the risk reduction level for the Emergency System is very difficult to be quantified by the actual SIL application (i.e., evaluated based on the single accident scenario, such as an accident from process control deviation), since the escalation scenarios after Loss of Containment (LOC) greatly vary depending on the plant design and equipment. Consequently, there are no clear criteria for evaluating the Emergency System design. This paper aims to provide the functional safety requirement (i.e., required risk reduction level based on IEC 61508 and 61511) as design criteria for the Emergency System.In order to provide clear criteria for the Emergency System evaluation, a risk reduction concept integrated with public’s perception of acceptable risk criteria is proposed and is applied to identify the required safety integrity level for the Emergency System design. Further, to verify the safety integrity levels for the Emergency Systems, the probabilistic model of the Emergency Systems was established considering each Emergency System (e.g., Fire and Gas System, Emergency Shutdown System and Emergency Depressuring System) relation as the Overall Emergency System. This is because the Overall Emergency System can achieve its goal by the combined action of each individual system, including inherent safe design, such as separation distance.The proposed approach applicability was verified by conducting a case study using actual onshore Liquefied Natural Gas Plant data. Further, the design criteria for Emergency Systems for LNG plants are also evaluated by sensitivity analysis.     

宝钢环境信息化系统建设探索

系统介绍了宝钢环境信息化系统建设架构、功能、特点,以及对污染减排、环境自动监测及信息化技术进行有效融合后的应用实践,并对该信息化系统在提高环境监控能力,完善系统建设上提出扩展监控范围、提升功能等构想.     

大型渡槽结构动力学研究进展

大型渡槽是灌区生命线工程中的关键性建筑物,其在地震及风载作用下的安全性已是渡槽建设的瓶劲,也是国内外研究的热点。渡槽结构的抗震、减震和抗风技术的核心是渡槽结构动力学的问题,而渡槽结构动力学系属流固耦合(FSI)系统的动力学范畴。在已有研究的基础上,首先对渡槽结构FSI系统模型的研究进行了总结和评述;然后简述了渡槽结构动力特性和响应的求解技术以及抗震、隔震、减震与抗风技术的研究概况;最后总结了渡槽结构动力学的研究进展,提出了该学科进一步研究的内容和方法。     

Tsunami survivors' perspectives on vulnerability and vulnerability reduction: evidence from Koh Phi Phi Don and Khao Lak, Thailand

This paper presents the results of primary research with 40 survivors of the 2004 Indian Ocean tsunami in two communities: Khao Lak (n=20) and Koh Phi Phi Don (n=20), Thailand. It traces tsunami survivors' perceptions of vulnerability, determines whether residents felt that the tsunami affected different communities differently, identifies the populations and sub-community groups that survivors distinguished as being more vulnerable than others, highlights community-generated ideas about vulnerability reduction, and pinpoints a range of additional vulnerability reduction actions. Tsunami survivors most consistently identified the 'most vulnerable' community sub-populations as women, children, the elderly, foreigners, and the poor. In Khao Lak, however, respondents added 'Burmese migrants' to this list, whereas in Koh Phi Phi Don, they added 'Thai Muslims'. Results suggest that the two case study communities, both small, coastal, tourism-dominated communities no more than 100 kilometres apart, have differing vulnerable sub-groups and environmental vulnerabilities, requiring different post-disaster vulnerability reduction efforts.