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81.
This paper studies the external costs of surface freight transport in Spain and finds that a reduction occurred over the past15 years. The analysis yields two conclusions: trucks have experienced a reduction in external costs, and rail has lower externalities. The external costs of road freight transport decrease between 1993 and 2007 (44%). The external costs of rail freight increase by 12%. During this period, the external costs of road freight related to climate increase by 16%, oppositely than those from air pollution and accidents (51 and 44%). The external costs of rail related to pollutant emissions and climate increase by 4% and 43%. Oppositely, the external costs related to accidents decrease by 27%. Road freight generates eight times the external costs of rail, 2.35 Euro cents per tonne kilometre in 2005 (5.6% accidents, 74.7% air pollution and 19.7% climate) vs. 0.28 (13.4% accidents, 53.9% air pollution and 32.7% climate). 相似文献
82.
83.
为了研究预制钢筋混凝土工业结构的地震响应,根据欧洲研究课题组在最新的试验研究中所用的试验原型,建立了SAP2000模型来模拟试验过程.数值模拟将主要研究该结构在不同的地震强度下的往复荷载.数值分析表明,文中的分析模型和方法可以再现试验过程,具有较高的仿真精度,为SAP模型用于分析结构的地震响应提供了依据. 相似文献
84.
针对轿车在总布置基本尺寸及硬点的确认过程中,如何确保设计轿车具有较好的乘降陛能(出入车方便性),文章从驾驶员和乘员与汽车门洞、座椅、方向盘、B柱、门槛及车门等方面阐述了进出车厢方便性能的主要因素及相关尺寸的设计控制方法,提出了一些供设计者参考的设计经验数值,指出任何尺寸定义都不能独立于其他尺寸或硬点的定义之外,要考虑造型、结构、安全及性能等方面要求。 相似文献
85.
参考国际上较为通行的统计标准,将城市轨道交通分为地铁、轻轨和有轨电车3大类,对世界城轨交通运营现状进行统计。分析表明,截至2018年底,全球有72个国家和地区的493座城市开通了城市轨道交通系统,里程超过26 100 km,其中地铁、轻轨、有轨电车各占54%、5%和41%;2017年,全球地铁和轻轨累计运送客流600.54亿人次,平均客运强度1.08万人次/(d·km)。其中,我国城轨交通线路共187条,运营里程达5 766.7 km,运送客流超过184.4亿人次。2018年我国16座城市开通新增或延伸线路36条,共734.0 km。我国线网规模和客流规模居全球第一,但网络化运输组织模式较国外相比有待丰富。 相似文献
86.
卢文军 《电力机车与城轨车辆》2002,25(4):24-25
通过对R407C制冷剂进行理论分析和性能试验,研究其在列车空调机组上替代R22制冷剂的可行性及应注意的问题。 相似文献
87.
ABSTRACTThe Belt and Road (B&R) initiative was introduced by the Chinese government to promote the worldwide economic development and multilateral cooperation between China and the associated countries. As a crucial part of global supply chains, transportation plays a key role to ensure the implementation of the B&R. Safety is one of the issues with great importance in transportation research. However, its foci have been expanded from traditional risk through security to resilience and sustainability. Resilience has attracted considerable interests from both researchers and practitioners across different research domains in recent years. Various studies have been conducted on transportation resilience from different perspectives. Consequently, different definitions have been developed to define and describe resilience. This paper presents a systematic review on transportation resilience with emphasis on its definitions, characteristics, and research methods applied in different transportation systems/contexts. It aims to figure out what transportation resilience is and what kind of essential characters it usually has. More importantly, research challenges are analysed and a future research agenda on the resilience of transportation systems is proposed. This paper will provide comprehensive insights into understanding the transportation resilience, as well as establish new horizons for relevant research topics within the context of the B&R. 相似文献
88.
This paper examines the possible placement of Energy Storage Systems (ESS) on an urban tram system for the purpose of exploring potential increases in operating efficiency through the examination of different locations for battery energy storage. Further, the paper suggests the utilisation of Electric Vehicle (EV) batteries at existing Park and Ride (P&R) sites as a means of achieving additional energy storage at these locations. The study achieves this through MATLAB modelling utilising captured GPS data and publically available information. This study examines the scenario of uni-directional substations with no interconnection between the overhead catenary for both directions of travel, and discusses the trade-offs between ESS size and required current limits.The results show the savings in both energy and basic CO2 emissions alongside the discussion of Return on Investment (RoI) that can be achieved through the potential installation of ESS at identified ideal locations along the tram network. Moreover, this may be extended to the use of EVs as stationary ESS sited at the existing P&R facilities. Further, the model may also be used to inform future infrastructure upgrades and potential improvements to air quality within urban environments. 相似文献
89.
程耀东 《兰州交通大学学报》2000,19(1):35-37
以AutoCADR14为绘图支撑软件,采用AutoCADR14的最新开发系统ARX和Visual C++5.0语言环境,在分析分幅地形图之间关系的基础上,对分幅地形图DWG文件的图形数据库的操作和拼接方法进行了研究。 相似文献
90.
罗琼 《重庆交通大学学报(自然科学版)》2012,31(Z1):583-585,614
停车换乘(P+R)作为城市交通系统中的重要组成部分,已经被许多发达国家所采用,并发挥了积极的作用。而对于新建P+R设施的地区来说,需要对其进行详细的分析,以达到修建P+R设施的目的。以重庆市观音桥地区预建的3个P+R设施为研究对象,先以确立选址合理和满足需求为重要评价指标,建立评价集。经观音桥地区现状调查,评价了P+R设施位置的合理性。然后,结合二项Logit模型,对P+R设施进行了需求预测,评价了设施的规模对缓解中心区交通的作用。 相似文献