希望花儿开 朵朵放光彩

莘莘的学子,当你迈着矫健的步伐前行,有多少人在为你默默地祝福,有多少人在为你保驾护航,在你迈向康庄大道的途中,还有无数默默为你奉献的,素昧平生的可人儿,那些奉献大爱的人们……不见不散的约定一座大山,一架小桥,一片爱心,一次凝聚,永恒的瞬间被幸福地定格     

虽千万桥吾往矣——纪念首座“茅以升公益桥”竣工

当爱心小桥在重庆市彭水自治县竣工的那一刻,孩子们笑了,村民们笑了,志愿者们笑了,为小桥付出心血的人们都笑了。那一刻是满足,那一刻是凝聚,那一刻是传承,那一刻是心灵的共鸣。"道之所在,虽千万人吾往矣。"道之所在,虽千万桥吾往矣。修桥过程是枯燥的、艰难的,但想到人心所向的小桥能够造福一方百姓,关注小桥工程的爱心人士们都会勇往直前,     

我国寒带地区客运车型的选择

一、安全性的原则 寒带地区由于车内外温差大,车内空气水分含量高,所以非常容易在车辆的前风挡,司机窗上出现结霜的情况,从而会影响司机的视野清晰度;由于风雪较多,还会出现后视镜积雪的情况,都会影响到司机的视野,进而影响到安全性.同时寒冷的气候会导致制动管路结冰,影响行车的安全性.     

网络话题

热心的网友总能提出各种各样的问题,当然,我们不能苛求网友提的问题能"一针见血",或者,总能提出一些新问题。不过,有时候,网友确实是"与时俱进"了,他们根据正在发生的事情,提出了自己的问题,但还是有人觉得这些问题是老问题,那么,症结就不在网友,而在环境了。大型汽车集团对客车总是有"野心",有"想法",但也好像不是很重视,于是,他们在客车行业中,姿态甚高,但成绩却并不理想,而且颇有反反复复的态势。今年客车行业整体态势不错,有几个汽车集团,也在今年高调进军,成绩如何,看网友如何议论。     

借助"比较优势"再攀运输高峰——河北省道路运输管理局局长于志伟专访

2003年以来,河北省道路运输管理部门结合行业实际,提出了"抓重点,促发展,抓科技,上档次,抓重点,求突破"的发展思路,明确了"以人为本",依法行政,安全稳定,科学发展"的发展理念.     

做中国公交文化捍卫者——访中国城市公共交通博物馆筹建人侯翔

一个秋日的午后,打开紧闭的房门,映入眼帘的是满地的纸张、公交车照片和堆砌的书籍、文件,房间不大,却盛满各种各样的收藏,有大的、小的,厚的、薄的,彩色的、黑白的:还有显露的、尘封的…….     

关于道路货物运输三个关键问题的探讨

改革开放以来,道路货物运输行业以市场化改革为导向,从无到有,从小到大,从弱到强,初步形成了多种经济成分并存、服务种类齐全的运输体系,为社会经济可持续发展奠定了坚实的基础。但是,随着货物运输行业市场化程度的不断深入,道路运输的管理模式、发展模式均受到了一定的挑战,尤其是随着燃油税费改革的实施,这个问题更加凸显。如何在新的形势,分析道路货物运输行业的关键问题,转变管理模式,厘清管理思路,进而促进道路货物运输的发展,已成为道路运输管理机构亟待正视的问题。     

杨传堂履新

在8月1日召开的交通运输部领导干部大会上,中组部王尔乘副部长对杨传堂有一段介绍。他说,杨传堂同志政治上坚定,经过多岗位特别是复杂艰苦环境的锻炼,领导经验丰富,熟悉党务和经济工作。思路清晰,组织领导和驾驭全局的能力比较强。敢于负责,处事果断,推动工作力度大。事业心强,工作热情高,重视调查研究。作风民主,善于听取各方面意见,注意调动大家的积极性。为人正派,团结同志,要求自己严格。中央认为,杨传堂同志是交通运输部主要领导的合适人选。     

历史大道的惊鸿一瞥——探寻北京西山古道

冉冉时光,悠悠岁月。中国,历史悠久的文明古国,在蹉跎与峥嵘的洗礼下,造就了极为丰富的文化遗产,而这些遗产是沉淀、是智慧、是财富,是各族人民精神的传承。当下,保护、管理、利用好祖国的文化遗产成为这代人维系中华民族血脉,弘扬优秀传统文化的历史使命。在近期全国第三次全国文物普查百大新发现评选活动中,经过普查机构的遴选、推荐,以投票方式选出     

桥之所至 心之所安

<正>当城市的孩子们坐着轿车去上学的时候,在边远贫困地区,有一群和他们同样如花年龄的孩子,或踩着水中的石头,或溜着跨江的钢索,或伏在老师的背上,正跋涉在艰难的上学路上……这些孩子随时都可能上演生死考验,有些孩子甚至付出了生命的代价——2011年11月4日,在海南屯昌县乌坡镇一名15岁花季少女小敏,在她每天上学必经的断桥处被河水冲走,永远告别了她的学校。     

Substantial Changes and Their Impact on Mobility: A Typology and an Overview of the Literature

During the past 40 years, mobility patterns have enduringly changed several times as a result of the occurrence of a number “substantial changes”. Examples of such substantial changes are the rapid emergence of affordable air travel, the oil crises, and profound ICT developments. To most researchers and policy-makers in transportation, it seems more than likely that the next 40 years will also witness a number of substantial changes, some of which might even have larger impacts on mobility than the ones described above. However, literature on substantial changes and their impact on mobility are difficult to access as it is spread across different research fields and suffers from ambiguous use of terminology. As a result, overview of the literature on substantial changes and their findings is missing and discussions on the impacts on future mobility of potential substantial changes are hampered. To overcome these problems, this paper (1) proposes a typology of substantial changes and (2) ties together and reviews the scholarly literature that has focused on identifying the impacts of past substantial changes on mobility patterns. In this paper, we show how the proposed typology on substantial changes can be applied to contemplate on substantial changes and on their impacts.     

Impacts of fuel quality on indoor environment onboard a ship: From policy to practice

Environmental considerations, concerning the negative impacts of ship exhaust gases and particles on ambient air quality, are behind the requirements of cleaner marine fuels currently applied in designated emission control areas (ECAs). We investigated the impact of a ship operating on two types of fuel on the indoor air quality onboard. Gaseous and particulate air pollutants were measured in the engine room and the accommodation sections on-board an icebreaker operating first on Heavy Fuel Oil (HFO, 1%-S), and later Marine Diesel Oil (MDO, 0.1%-S). Statistically significant decrease of SO₂, NOx, PM_2.5 and particle number concentration were observed when the ship was operating on MDO. Due to the higher content of alkylated PAHs in MDO compared to HFO, the concentration of PAHs increased during operation on MDO. The particulate PAHs classified as carcinogens, were similar to or lower in the MDO campaign. Chemical analysis of PM_2.5 revealed that the particles consisted mainly of organic carbon and sulfate, although the fraction of metals was quite large in particles from the engine room. Principal Component Analysis of all measured parameters showed a clear difference between HFO and MDO fuel on the indoor environmental quality on-board the ship. This empirical study poses a first example on how environmental policy-making impacts not only the primary target at a global level, but also brings unexpected localized benefits at workplace level. The study emphasizes the need of further investigations on the impact of new marine fuels and technologies on the indoor air environments on board.     

Physical environments influencing bicyclists’ perception of comfort on separated and on-street bicycle facilities

This study investigates the impacts of physical environments on bicyclists’ perceptions of comfort on separated and on-street bicycle facilities. Based on a field investigation conducted in Nanjing, China, we find that physical environmental factors significantly influencing bicyclists’ perception of comfort on the two types of facility. Cyclists’ comfort is mainly influenced by the road geometry and surrounding conditions on physically separated paths while they pay attention to the effective riding space and traffic situations on on-street bicycle lanes.     

Learning aircraft operational factors to improve aircraft climb prediction: A large scale multi-airport study

Ground-based aircraft trajectory prediction is a major concern in air traffic control and management. A safe and efficient prediction is a prerequisite to the implementation of new automated tools.In current operations, trajectory prediction is computed using a physical model. It models the forces acting on the aircraft to predict the successive points of the future trajectory. Using such a model requires knowledge of the aircraft state (mass) and aircraft intent (thrust law, speed intent). Most of this information is not available to ground-based systems.This paper focuses on the climb phase. We improve the trajectory prediction accuracy by predicting some of the unknown point-mass model parameters. These unknown parameters are the mass and the speed intent. This study relies on ADS-B data coming from The OpenSky Network. It contains the climbing segments of the year 2017 detected by this sensor network. The 11 most frequent aircraft types are studied. The obtained data set contains millions of climbing segments from all over the world. The climbing segments are not filtered according to their altitude. Predictive models returning the missing parameters are learned from this data set, using a Machine Learning method. The trained models are tested on the two last months of the year and compared with a baseline method (BADA used with the mean parameters computed on the first ten months). Compared with this baseline, the Machine Learning approach reduce the RMSE on the altitude by 48% on average on a 10 min horizon prediction. The RMSE on the speed is reduced by 25% on average. The trajectory prediction is also improved for small climbing segments. Using only information available before the considered aircraft take-off, the Machine Learning method can predict the unknown parameters, reducing the RMSE on the altitude by 25% on average.The data set and the Machine Learning code are publicly available.     

Passenger conveyor economics

Operating and capital costs for a high speed conveyor are estimated from cost data for low speed conveyors and from estimates for high speed designs. Unit costs are developed with reference to theoretical and practical conveyor capacities, and to the effect of traffic peaking on average utilization. User benefits are modelled as the change in consumers surplus arising from the introduction of a conveyor on a linear street as an alternative to walking. Cost and benefits vary widely depending on system design and location and on characteristics of travellers. Benefit measurements should reflect the effects on travel demand of a proposed installation, changes in value of time with changes in mode, and the effects of benefit “dilution” associated with limitations on access to the conveyor.     

Influence of 3D printing on transport: a theory and experts judgment based conceptual model

Consumer 3D printing is on the rise and has the potential to significantly change the transport and logistics sector. Current literature on 3D printing and transport studies does not provide a systematic model of the impact of 3D printing on transport and related (policy relevant) areas, such as traffic safety, location decisions, accessibility and environmental effects. Based on a literature review and two rounds of expert consultation, we propose and refine a conceptual model as a way to approach this gap in the literature. The expert consultation yields that the conceptual model comprises the relevant and important elements for assessing the impact of 3D printing on transport and transport-related challenges. Location, needs and transport resistance are important: (a) city-level hubs are the most likely locations for 3D printers because they can coordinate material flows and gather expertise; (b) mass-individualisation and personification dictates the needs for 3D printers; (c) distribution networks will be organised more efficiently, less empty vehicles, but raw materials still need shipping. However, experts’ opinions diverged on the impact of 3D printing on transport volumes and environmental impacts.     

地质顺层偏压隧道围岩压力及其分布特点的试验研究

结合渝怀铁路渔塘湾隧道所处的地质顺层偏压特点,按照相似理论,对地质顺层岩体作用于隧道衬砌结构上的偏压载荷进行了模型试验,初步得出了地质顺层偏压隧道围岩压力的分布特点及其与不同顺层倾角之间的变化关系,并就顺层岩体隧道结构的形式和支护措施进行了探讨。     

贝雷架钢桥的静动力荷载试验研究

文章结合工程实例,通过对贝雷梁桥梁静动力荷载试验,指出贝雷架钢桥连接部分存在联系不够紧密、桥梁横向分配性较差、桥面的振动感觉明显及钢梁易锈蚀等问题。提出了改善贝雷架钢桥结构的力学性能和使用状况,加强结构的定期检查及监测等相关建议。     

呼包鄂地区农村道路国防功能探讨

文章根据呼包鄂三地区的地域特征和经济地位,结合目前农村道路国防功能建设要求,提出当前修建农村道路时增强其国防功能的几点建议,以期对内蒙古乃至全国农村道路的建设和国防交通事业有所帮助。     

The effects of on‐street parking on the service rate of nearby intersections

An on‐street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by the following vehicles. If the maneuver occurs near a signalized intersection, the service rate of the intersection might be reduced. In this paper, a model is built to analyze the effects of parking maneuvers on the intersection service rate. Based on the hydrodynamic theory of traffic flow, the perturbation caused by the parking maneuver is analyzed. Using dimensional analysis, we illustrate the relation between the background conditions, the distance from the parking area to the intersection, and the intersection service rate. Based on this relation, one can compute the service rate reduction caused by existing on‐street parking areas. A minimum distance between the parking area and the intersection to avoid such reduction can be accordingly found. Numerical examples based on empirical data from the city of Zurich, Switzerland, are provided to illustrate the practical applications. Although the analysis is based on streets with a single lane per direction, the findings can provide some insights regarding different situations. We hope such findings can be used as a basis for developing on‐street parking design guidelines. Copyright © 2015 John Wiley & Sons, Ltd.