采用新技术,减少轮轨磨耗

印度铁路部门正在对一种旨在减少轮轨磨耗的新技术进行研究 ,这种所谓的“能量抑制”技术 ,可能为解决径向转向架设计有关问题提供了另一种途径     

Multi-Body Dynamics in Full-Vehicle Handling Analysis under Transient Manoeuvre

This paper presents a 94 degrees of freedom non-linear multi-body dynamics model of a vehicle comprising front and rear suspensions, steering system, road wheels, tyres and vehicle inertia. The model incorporates all sources of compliance: stiffness and damping, all with non-linear characteristics. The model is used for the purpose of vehicle handling analysis. A simulation run, pertaining to a double lane change is undertaken in-line with the ISO 3888 standard.     

Travellers’ perceptions of travel time reliability in the presence of rare events

Transportation - Travellers account for variability in transport system performance when they make choices about routes, modes and destinations. Modellers try to quantify travel time reliability...     

Adaptation planning for climate-resilient urban infrastructures

This paper analyzes the interdependency across two critical infrastructures of transportation and motor fueling supply chains, and investigates how vulnerability to climatic extremes in a fueling infrastructure hampers the resilience of a transportation system. The proposed model features both a bi-stage mathematical program and an extension to an ‘α-reliable mean-excess’ regret model. The former aspect allows decision makers to optimize the pre-disaster asset prepositioning against the maximum post-disaster system resilience. The latter aspect of the proposed model devalues the impact of ‘low-probability, high-cost’ sub-scenarios upon model results. The model reveals the reliance of post-disaster urban mobility on the interdependent critical infrastructure of motor fueling supply chains. The results also suggest how investment in the fueling infrastructure’s vulnerable elements protects urban mobility while the transportation network is stressed or under attack.     

A methodological framework for a priori selection of travel demand management package using fuzzy MCDM methods

Transportation - A robust and scientific selection of appropriate Travel Demand Management (TDM) measures is likely to ensure that the purpose of their implementation is met. The existing methods...     

极端复杂地质条件下TBM隧道施工关键技术研究及应用北大核心CSCD

大瑞铁路高黎贡山隧道、引汉济渭秦岭隧洞、滇中引水香炉山隧洞等工程的相继开工建设,使富水破碎极软地层带来的TBM卡机、高地应力极硬岩地层带来的岩爆等TBM施工问题日益凸显。文章首先对比阐述了国内TBM隧道工程建设过程中常遇到的软弱破碎、极硬花岗岩等典型不良地质及其对TBM掘进所带来的影响,在总结分析辽西北供水、引松供水、引洮供水等工程建设过程中出现的隧道局部塌方、TBM卡机等案例及其影响因素的基础上,以极端复杂地质条件TBM掘进关键技术为对象进行了系统研究论述,结果表明:(1)超前地质预报技术是TBM施工应对极端复杂地质的重要手段,但目前尚无法对前方中远距离地质状况进行准确量化预测;基于微震监测分析结果,根据可能发生的轻微、中等、强烈等不同等级的岩爆,制定对应处置措施;节理发育、炭质板岩、断层破碎带等不同软弱破碎地层,应采取针对性的防卡机措施,同时可根据不良地质段的长度来选择合适的脱困方案;(2)TBM推力、推进速度、刀盘转速及扭矩等掘进参数的异常波动,是表征掌子面前方地质条件状态的重要指标,TBM掘进前,根据前期预判的全断面硬岩、软弱破碎等围岩条件,分别选择合适的掘进参数;TBM掘进过程中,应基于掘进参数异常变化,纠正地质条件预判并采取对应的调控措施,进而确保TBM处于最佳掘进状态;(3)针对既有TBM难以适应现有地质条件的情况,以引洮供水隧洞、引红济石隧洞、引汉济渭隧洞等工程为例,对TBM改造技术进行了分析论述。最后,针对极端复杂地质条件下的TBM隧道工程建设新问题及其应对措施进行了展望与探讨。     

How do they get by without cars? An analysis of travel characteristics of carless households in California

Transportation - In spite of their substantial number in the U.S., our understanding of the travel behavior of households who do not own motor vehicles (labeled “carless” herein) is...     

Logistics as a driving force for development under the Belt and Road Initiative – the Chinese model for developing countries

ABSTRACT

An important objective of “the Belt and Road Initiative” is to promote the economic growth of countries in the region. China’s successful development experience, proposed in the initial stage of reform, can be summarised as “Looking for development, building the highway first”. This study is the first to evaluate whether logistics infrastructure has indeed contributed to economic growth by employing an error correction model with panel data from 2003 to 2014. In addition, we compare the influence levels of different sectors of logistics infrastructure in different regions, i.e. developed and developing regions. We focus on developing regions as they represent good development experiences for developing countries in the Silk Road Economic Belt. For developing regions, we find that the most influential factors are telecommunication and airway transportation, which should be the foci of attention in order to promote economic growth and reduce inter-region economic inequalities. The research confirms that logistics is indeed a driving force for economic growth in China, and that the contributions of specific sectors can be a useful reference for developing countries to determine prioritisation of investment in different logistics sectors across regions.     

STUDY ON MAXIMUM SPECIFIC SLUDGE ACTIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

IntroductionGranular sludge UASB (Up- flow AnaerobicSludge Bed) reactor is the most widely used anaer-obic waste water treatmentreactor in the world.Itbelongs to the second generation of modern anaero-bic reactor. EGSB(Expanded Granular SludgeBed) reactor is an even higher efficient anaerobicwastewater treatment reactor,which is developedin the past ten years based on the UASB technolo-gy.It belongs to the third generation of modernanaerobic reactor. EGSB includes two kinds oftypes:I…     

宋元时期闽南海外贸易中的商业活动

史书中并没有详细记载海外贸易活动是如何组织起来的.尽管我们从一些线索中可以了解当时的一些贸易活动,但很难证明其普遍存在,更不能断定它们已代表所有当时的活动.下面讨论的几种贸易模式仅仅是一些贸易活动的例子,藉以说明闽南商业的特色.……