城市轨道交通运行评价指标体系

随着我国城市轨道交通的大规模建设,迫切需要开展基础理论及关键技术的研究并制定相应的建设、设计标准。必然要从运行评价指标体系入手,在保证车辆的运行安全性、平稳性和旅客的舒适性前提下,制定合理的线路设计参数,选择合理的车辆类型和轨道结构类型,从而降低工程造价,加快建设速度。笔者综述了城市轨道交通的运行评价体系,并给出了其参考取值,为城市轨道交通的建设提供了技术支持。     

A Successful Pilot Project of Decentralized Household Waste Management in Brazil

Summary Present municipal waste management paradigms in Brazil do not allow for flexible approaches to solving an extremely dynamic problem. This paper discusses the basic flaws in present thinking models of residents and municipal administrators. Fundamental arguments presented on municipal solid waste relate to nomenclature, destinations, definitions, logistics, social dynamics, social assistance programs, education and employment philosophies. In each case, the consequences of the stalemate are explained in terms of the unsustainable situation of constantly growing landfills. In sequence, a proactive thinking model is presented and explained that has the potential of drastically reducing landfill size. It is called Municipal Transit Material Processing. The model has been tested successfully in small communities and is now available for scale-up. The landfill diversion achieved stands at 62% of household waste in comparison with 15% theoretically possible in Brazil with selective collection models. Although of necessity the arguments apply directly to Brazil, the basic ideas behind the reasoning may be extrapolated to other Southern countries. The following simple example will illustrate to the reader the type of paradigm inversion the paper proposes to convey. The classical political slogan in Brazil is “get children out of garbage dumps”. The inversion proposed and explained is “do away with garbage dumps”.     

直线电机轮轨交通系统安全性分析

直线电机轮轨系统采用直线感应电机牵引 ,轮轨系统支承导向 ,是一种在技术、经济、环保方面均具有良好性能的新型城市轨道交通系统。该系统有两种主要技术模式 ,均有良好的安全运营记录。笔者介绍了系统的性能和设计特点 ;从牵引制动系统、控制系统、管理系统、养护维修系统以及防灾系统 5个方面对系统的安全性设计方法进行了总结 ;认为该系统具有良好的安全性能 ,先进的安全管理理念以及健全的安全防护系统 ;特别强调对该系统进行的安全设计研究 ,将为提高我国城市轨道交通系统的安全性提供新的思路     

Latin American busways: moving people rather than cars

The rapid growth of Latin American urban centres beginning in the 1970s placed a heavy strain upon urban transport service providers. Facing high population growth from a citizenry dependent upon public transport and having limited financial resources to develop car‐based infrastructure, Latin American municipal planners were challenged to create a new transport paradigm. One ingenious response to this dilemma was the busway, a surface metro system that utilizes exclusive right‐of‐way bus lanes. The developers of the Latin American busways astutely observed that the ultimate objective was to swiftly, efficiently and cost‐effectively move people rather than cars. Examples of innovative busway systems are presented from Curitiba, Bogota, Porto Alegre, Quito and Sao Paulo. The low cost, flexibility and speed of the exclusive busways all contribute to extremely high levels of customer satisfaction. Innovative approaches to the design of busway loading stations and simplified ticketing have also helped to reduce operating costs and improve customer flows. Additionally, clear system maps, colour‐coded routing, system safety and cleanliness and superior customer service have helped direct consumer preference towards the busway. The success of busways has also proved that costly subway systems or uncontrolled sprawl are not the only options available to municipal planners. The Latin American busway corridors provide high peak capacities that permit busway corridors to serve the transit requirements of most medium‐ to large‐sized cities. When integrated with progressive land‐use policies, busways can also form the basis of more sustainable urban design by encouraging development corridors with high‐density, mixed‐use land use. The environmental benefits and calming influences afforded cities by busway systems have translated into dramatically improved levels of quality of life indicators, including improvements in health, crime reduction and poverty alleviation. The user‐friendliness and cost‐effectiveness of busway systems have convinced municipal leaders in North America, Europe and Australia to develop similar systems of their own. Latin American busways thus provide a unique example of South to North technology transfer.     

快速交通对区域中心城市日常可达性影响——以长江三角洲地区为例

近年来高速公路、高速铁路等快速交通不断发展,城市区域可达性得到大幅提高。基于栅格数据的成本加权距离法,利用平均旅行时间、等时圈以及日常可达性等区域可达性指标,比较分析有无高速公路和有无高速铁路情况下长三角地区中心城市可达性空间格局变化,探索两种快速交通方式对中心城市可达性的影响差异。结果显示：由于高速公路网发育程度较好,对城市区域可达性的影响较为均衡,而高速公路桥能显著缩短两岸旅行时间;高速铁路运行速度更快,但主要沿大城市带呈线状分布,因此对沿线可达性改善明显,尤其是对铁路端点城市;高速铁路较高速公路对城市之间日常可达时间优化效果显著;高速公路和高速铁路对于可达性影响各异,需衔接配合方能大幅提高城市日常可达性,促进区域经济社会公平快速发展     

便携式水质检测仪性能综合评价方法研究

目前便携式水质检测仪品种繁多,各种技术指标和性能尚无统一评价标准,导致仪器性能良莠不齐,监测数据质量难以保证,无法满足管理部门对环境监测数据的要求,检测机构在采购过程中也难以选择。为解决这一问题,建立了便携式水质检测仪综合评价方法,确定了综合评价指标,制定了综合评价标准,选择相关仪器及相关项目进行综合评价。结果表明,大部分便携式水质检测仪器在便携性、操作简易性等方面做得比较好,而在准确度、精密度等方面还有待提高。该评价方法综合考虑了影响便携式水质检测仪的各项因素,能够为全方位评价、选择便携式水质检测仪提供参考。     

南京城市轨道交通网络化运营安全管理对策研究

城市轨道交通网络化运营在更加显现便捷性,导致客流大幅度增加的同时,也给运营安全带来新的严峻挑战。本文分析了网络化运营给安全管理带来的新矛盾和新问题,研究提出了相关对策并在实践中应用,确保了南京城市轨道交通网络化运营安全生产总体形势持续平稳。     

快速公交车站站台门系统的设置探讨

介绍了快速公交BRT站台半高安全门的设计基本要求及系统的主要构成、运行模式、技术条件并与地铁半高安全门进行了比较,给出了其设计选型的合理建议.     

基于熵权的属性识别模型在城市轨道线网方案评价中的应用

城市轨道线网规划对优化城市社会、经济、生态环境,实现城市生态环境可持续发展有着至关重要的作用。文章通过熵值法与属性识别模型相结合,建立了基于熵权的属性识别模型,用该方法对城市轨道线网方案进行综合评价,并结合西安市城市轨道交通线网规划中的4个预选方案进行了评价,推选出最优方案。结果表明,该评价方法结果合理,决策科学,具有较好的应用前景。     

API standard 521 guidance on mixing of hot/cold liquids and prevention of superheat limit explosions

American Petroleum Institute (API) standards and recommended practices have identified inadvertent mixing of hot and cold liquids as a potential cause for equipment overpressure since 1955. The limited guidance has been informative but provides minimal if any details on conditions that could cause an overpressure and its potential severity. Therefore, the user must interpret how and when to prevent and/or mitigate the scenario. This guidance has changed little over the years. In June 2020, API published the 7th Edition of API Standard 521 which now provides specific guidance as to conditions whereby pressure relief devices can be considered for protection and conditions where prevention remains as the only recourse. This paper discusses the basis for the revised guidance in API Standard 521 and includes supplemental guidance.