Water Network Synthesis Using Mutation-Enhanced Particle Swarm Optimization

Different techniques for the synthesis of industrial water reuse/recycle networks have been developed in recent process integration research. These tools range from graphical pinch analysis approaches to mathematical programming models. The latter have the advantage of being flexible enough to incorporate various water network constraints, but in many cases these are often non-linear, thus making the identification of global optima difficult. Recent work has demonstrated the effectiveness of metaheuristic algorithms such as particle swarm optimization (PSO), for finding good solutions these problems. This work describes the use of a modified PSO for solving mixed integer non-linear programming (MINLP) models for water network synthesis. By incorporating a mutation operator for the binary variables in the model, the algorithm is able to escape sub-optimal network topologies and proceed towards better solutions than can be found with ordinary PSO. Two case studies involving water recycle/reuse are used to demonstrate the new design methodology.     

Formalising informal solid waste recycling at the Pomona dumpsite in Harare,Zimbabwe

The role of informal recycling in poverty alleviation and solid waste management in cities in developing countries has been receiving increased attention. This study explores the integration of the informal recycling sector with the Harare City Council's solid waste management system, focusing on the Pomona dumpsite. The extent of this integration was compared with interventions proposed in InteRa, a new way of evaluating the integration of informal recyclers with the waste management systems of cities in developing countries. Our results suggest that the Harare City Council, which had the vision of transforming itself into a world‐class city, failed to fully integrate the informal recycling sector. We suggest to policymakers that complete integration of the informal sector will not necessarily prevent cities from achieving such visions. Rather, addressing the neglected interventions may help in achieving their visions.     

不同情境下中国碳排放权交易市场的风险度量

以深圳、湖北、广东、上海及北京5个碳交易中心2015～2020年的日交易数据为基础,设置了Ave、Med、Max、Min4种交易情境,采用TGARCH-VaR模型对不同情境下的碳排放权交易市场风险进行了研究.结果表明,不同情境下碳排放交易市场风险存在差异,各情境的市场稳定性、政策响应度均存在一定规律:Ave情境碳现货收...     

长三角城市群旅游生态效率时空演化特征及其影响因素研究

长三角一体化是我国当前重要的国家战略之一,旅游业发展在助推长三角产业高质量一体化发展中扮演着重要角色。综合运用SBM-undesirable模型、核密度估计、空间分析等方法探索长三角城市群26个核心城市2007—2017年旅游生态效率时空演化特征,并运用面板Tobit回归模型探讨其影响因素。结果表明:(1)长三角城市群内旅游生态效率存在着显著不均衡性,研究期内旅游生态高效率城市有所减少,较高效率城市数量增加,低旅游生态效率城市增多且呈现向城市群西部敛缩的态势。(2)长三角城市群内旅游生态效率两级分化程度和地区之间的非均衡性在逐步减小。(3)长三角城市群旅游生态效率东部大于西部,北部大于南部,东西方向上非均衡性比南北方向更加显著。(4)长三角城市群旅游生态效率表现为以空间负相关为主的分布特征,空间异质性大于空间集聚性。(5)旅游经济规模、旅游产业结构、科技创新水平、城镇化发展、经济发展水平、建成区绿化覆盖率和对外开放水平对城市群整体和不同省市旅游生态效率影响的空间异质性较强。     

在环境地学研究中应用GIS急需解决的问题分析

地理信息系统已经成为环境地学的常用工具，但主要被用来存储和显示地图，没有发挥其应有的功能。本文认为多源空间数据集成、空间数据分析和挖掘队及模型集成等是其中三个最主要问题。多源环境数据集成是基础，空间分析是连接多源数据集成与模型集成的桥梁和纽带，数据通过这个桥梁传输给模型，模型对环境系统进行模拟和仿真。这些问题的解决有利于更好地在环境地学中应用地理信息系统。     

Graphical strategies for design of evaporation crystallization networks for environmental wastewater applications

This paper introduces graphical strategies for the design of an evaporation/crystallization network for ternary wastewater environmental applications. Sources, sinks and other streams are located on a ternary composition diagram. While a source is any wastewater stream that has the potential to be recycled, a sink is any unit in the process that can accept sources. The proposed methodology is extremely simple to understand and implement, as it only requires basic solid-liquid phase equilibria data and uses lever arm principles to generate alternative process designs. Geometric constructions are carried out on the ternary composition diagram and the respective lever arms are used to determine intermediate flow rates in the evaporation/crystallization network. The relative locations and flow rates of the sources and sinks under consideration, as well as the unique shape of the solid-liquid equilibrium, drive the design of the separation (via evaporation/crystallization) network. Some generic structures are proposed for a typical evaporation and crystallization network. Once the general problem statement has been defined, special cases consisting of a single source-single sink, single source-two sinks and two sources-single sink are described. These special cases are representative of commonly occurring industrial wastewater design problems. Several graphical insights are listed that allow one to represent evaporation and crystallization operations on a ternary triangular composition diagram and avoid mathematical complexity. The possibility of bypassing a part of the initial feed streams is also considered. Certain feasible composition regions are identified on the ternary composition diagram for cases dealing with multiple sources and sinks. The methodology is useful in pre-screening and eliminating certain sources/sinks and is readily applicable to cases with lower number of sources and sinks. A case study involving the ammonium nitrate manufacturing process is included to demonstrate the broad applicability and value of the proposed approach.     

飞行器控制系统数据综合关键技术研究

控制系统数据综合是导弹等飞行器实现低成本和小型化的有效途径.文中提出基于双处理器结构的飞行控制系统任务计算机系统结构,并对数据综合过程中的时间同步、时间管理等关键技术问题,采取初始同步和周期同步相结合的方式,对任务运行同步误差进行了修正,在时间同步的基础上,将控制链条按照资源占用情况进行分解,并对各功能模块进行统筹、分时调度,实现了双机并行处理.     

考虑峰后软化的圆形巷道稳定性分析及工程应用

为获得更准确的巷道围岩应力分布和变形特征,基于统一强度理论,考虑围岩塑性软化和中间主应力的影响,引入塑性软化参数,推导出巷道围岩弹塑性区应力、塑性区范围和位移的表达式。通过算例分析,得到塑性软化系数和中间主应力等相关参数对巷道围岩应力分布、塑性区半径和位移的影响规律。研究结果表明:随内摩擦角软化系数和黏聚力软化系数的增大,围岩塑性区半径和位移呈现先急剧后缓慢的减小趋势;中间主应力系数对巷道围岩弹塑性应力有着显著影响,中间主应力系数越大,围岩塑性区半径和位移越小。     

城市污水处理过程中溶解性有机物及荧光物质的变化规律

以锦州市W污水处理厂为研究对象,利用三维荧光光谱分析技术和荧光区域积分(FRI)方法考察了城市污水处理过程中溶解性有机物及荧光物质的去除状况.利用XAD树脂将DOM分为5个部分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPIA)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).结果表明,HPO-A和HPI是该污水处理厂进水中的主要DOM组分,并且DOM中的荧光物质主要为类芳香族蛋白质荧光物质和类富里酸荧光物质.在该污水处理厂内,生物降解作用是TPI-A和HPI的主要去除机制,HPO-N和TPI-N主要是由深度处理工艺(絮凝-沉淀-过滤)去除的,生物处理工艺和深度处理工艺对HPO-A的去除能力接近,而生物处理工艺和深度处理工艺对TPI-N的去除效果均较差.生物处理工艺对HPO-A、TPI-A和HPI中的荧光物质有较强的去除能力,而对HPO-N和TPI-N中荧光物质的去除效果较差.深度处理工艺能够有效去除HPO-A和HPO-N中的荧光物质,而对TPI-A、TPI-N和HPI中的荧光物质无明显去除作用.     

外军装备维修及对我军弹药维修的启示

首先介绍了外军装备维修的现状和发展趋势,之后指出了我军弹药维修存在的问题,最后得出对我军弹药维修保障发展的启示。认为我军弹药维修保障应向军民一体化方向发展,开展全寿命保障,提高保障信息化水平,进行弹药两级维修体制的论证,并倡导绿色维修的新理念。