考虑抢修时间的铁路应急物资配送与失效线路修复的集成优化

为提高铁路应急物资配送的快速响应能力,将应急物资配送与失效线路抢修结合在一起进行分析,指出了在应急救援初期资源有限的情况下,铁路网随失效线路抢修时间会不断变化.以追求最小化配送物资总延时和总的物资未满足量为目标,加入了线路抢修时间窗约束,建立了铁路应急物资配送和失效线路抢修的多目标集成优化模型,通过算例验证了模型和算法...     

城市内涝灾害防治困境的突破——基于数据治理模式的研究

城市内涝灾害已成为威胁人们生命财产安全、 滞缓社会经济发展的城市"顽疾",内涝灾害防治能力的提升迫在眉睫.首先从排水管网建设、城市蔓延、"信息孤岛"三个维度分析了城市内涝灾害防治所面临的困境,而后引入数据治理理念;在建立数据治理模型并对其原则框架、范围框架及实施和评估框架作出解读的基础之上,提出管网建设智能化、数据共享...     

城市生活垃圾卫生填埋场选址研究

结合城市垃圾卫生填埋场的实例和工程实践的经验,分别从城市总体规划、场址自然地理条件、填埋场的库容、场地外部建设条件和满足社会法律的要求等几个方面对填埋场的场址的选择做了详细的分析和探讨。     

重庆市碳排放现状及低碳经济发展战略研究

低碳经济以低能耗、低污染、低排放为基础,是当今世界减缓温室气体排放、应对气候变化的最佳经济发展模式。本文初步估算了重庆市包括二氧化碳排放总量、人均排放量、万元GDP排放强度等碳排放现状,分析了近年来全市碳排放减缓的趋势以及二氧化碳排放来源解析的结果,探讨了重庆市低碳发展的良好基础,提出了重庆市发展低碳经济的战略取向、战略目标、战略重点和战略措施建议,描绘了重庆市低碳发展的行动路线图,认为低碳经济是重庆市转变经济发展方式、实现可持续发展的必然选择。     

Outdoor and indoor cadmium distributions near an abandoned smelting works and their relations to human exposure

The relationship of measured or modelled Cd concentrations in soil, house dust and available to plants with human urinary Cd concentrations were assessed in a population living around a Cd/Pb/Zn smelter in the UK. Modelled air concentrations explained 35% of soil Cd variation indicating the smelter contributed to soil Cd loads. Multi-variate analysis confirmed a significant role of biological and life-style factors in determining urinary Cd levels. Significant correlations of urinary Cd with soil, house dust and modelled plant available Cd concentrations were not, however, found. Potential reasons for the absence of clear relationships include limited environmental contact in urban populations; the role of undefined factors in determining exposure; and the limited spatial scope of the survey which did not sample from the full pollution gradient. Further, the absence of any significant relationship indicates that environmental measures provide limited advantage over atmospheric model outputs for first stage human exposure assessment.     

燃煤电厂除尘器的应用和选择研究

对目前我国燃煤电厂中使用较多的几种除尘器——电除尘器、袋式除尘器及电袋复合除尘器的原理、发展及应用进行了介绍和阐述,并结合几种除尘器的特点和国内外运行实例,就我国燃煤电厂除尘器的选择提出了建议。     

Sensitivity of key factors and uncertainties in health risk assessment of benzene pollutant

Predicting long-term potential human health risks from contaminants in the multimedia environment requires the use of models. However,there is uncertainty associated with these predictions of many parameters which can be represented by ranges or probability distributions rather than single value.Based on a case study with information from an actual site contaminated with benzene,this study describes the application of MMSOILS model to predict health risk and distributions of those predictions generated using Monte Carlo techniques.A sensitivity analysis was performed to evaluate which of the random variables are most important in producing the predicted distributions of health risks.The sensitivity analysis shows that the predicted distributions can be accurately reproduced using a small subset of the random variables.The practical implication of this analysis is the ability to distinguish between important versus unimportant random variables in terms of their sensitivity to selected endpoints.This directly translates into a reduction in data collection and modeling effort.It was demonstrated that how correlation coefficient could be used to evaluate contributions to overall uncertainty from each parameter.The integrated uncertainty analysis shows that although drinking groundwater risk is similar with inhalation air risk,uncertainties of total risk come dominantly from drinking groundwater route.Most percent of the variance of total risk comes from four random variables.     

Treating design uncertainty in the application of Eco-indicator 99 with Monte Carlo simulation and fuzzy intervals

In incremental eco-design improvements, design engineers attempt to modify an existing product via some eco-design measures to reduce the product’s environmental impacts (e.g. reduction of material usage and energy consumption). In this process, several design concepts can be proposed, and concept selection is required to allocate resources sensibly to promising design concepts only. In this context, the research purpose is to estimate the environmental impacts of each concept given the uncertainty of design information. In the proposed methodology, the fuzzy interval arithmetic is used to specify and propagate imprecise design information. Then, the centroid concept is applied to model different views of imprecision (i.e. pessimistic, balanced and optimistic) associated with fuzzy impact assessment. Accordingly, a decision scheme is developed to support concept selection and suggest the potential areas for further eco-design improvements. A coffee maker is used as an example to demonstrate the proposed methodology. Also, the Monte Carlo Simulation is applied for the same example to compare the numerical outcomes by the fuzzy interval approach.     

应用地理信息系统进行垃圾填埋场选址的初步研究

在ArcGIS 8.3软件空间分析模块(spatial analysis)支持下,以江苏省长江以南市辖区为研究对象,进行了空间叠加和空间复合查询分析,以确定垃圾填埋场候选区域分布,并同已有的垃圾填埋场监测点进行比较,结果表明,利用地理信息系统技术进行垃圾填埋场辅助分析是可行的.     

Choice set formation for outdoor destinations: The role of motivations and preference discrimination in site selection for the management of public expenditures on protected areas

Effective public expenditure currently dominates the management focus of many protected areas. This calls for explicit modeling of constraints and motivations that, respectively, obstruct and stimulate visits to selected outdoor destinations. Choice set formation is the result of screening and/or inclusion of specific sites (alternatives) to form the set of sites considered in real choices. Evidence shows that the omission of a structural representation of choice set formation is harmful to econometric inference. Yet, the literature has largely ignored the underlying behavioral phenomenon. We show, using a discrete choice experiment involving selection among seven recreational sites in an Italian national park, that choice set formation is behaviorally relevant, even after controlling for preference discrimination. Motivations (why visit?) are important determinants of preliminary site screening for choice set inclusion, as well as site selection, justifying the additional value of such modeling extension.