首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   67篇
  免费   0篇
公路运输   3篇
综合类   16篇
水路运输   12篇
铁路运输   28篇
综合运输   8篇
  2020年   1篇
  2018年   2篇
  2017年   1篇
  2016年   1篇
  2015年   5篇
  2014年   8篇
  2013年   4篇
  2012年   4篇
  2011年   5篇
  2010年   3篇
  2009年   8篇
  2008年   8篇
  2007年   4篇
  2006年   6篇
  2005年   1篇
  2004年   2篇
  2001年   1篇
  1998年   1篇
  1996年   2篇
排序方式: 共有67条查询结果,搜索用时 15 毫秒
21.
吴俊 《铁道技术监督》2008,36(1):24-26,31
介绍OIML R106(2005—1CD版)《自动轨道衡》国际建议与JJG 234—1990《动态称量轨道衡》,分析两者之间的差异.并提出采标建议。  相似文献   
22.
“十五”期间,我国铁路以实施《中长期铁路网规划》为主要标志,展开了大规模、高标准的铁路建设,在扩大路网规模、提升工程标准、控制工程质量、规范建设市场、加强建设管理等方面取得了显著成绩。“十一五”是铁路跨越式发展的关键时期,也是大规模铁路建设最关键的阶段,要以确保建设规模和工程质量为重点,以扩大路网规模、优化布局结构,强攻客运专线、实现“一流的工程质量、一流的装备水平、一流的运营管理”为主要任务,充分利用和整合资源,结合技术引进和自主创新,加快构建一流技术标准体系,有序推进续转和新上项目,确保工程质量、安全、工期、投资。2006年是“十一五”开局之年,要加快前期工作,保证新项目如期开工,深化质量管理达标、工程分包专项治理和打击内业资料弄虚作假“三项治理活动”,加强安全专项整治,攻克征地拆迁、设计供图和技术问题,确保年度计划的完成。  相似文献   
23.
This paper is about distance and time as factors of competitiveness of intermodal transport. It reviews the relevance of the factors, evaluates time models in practice, compares network distances and times in alternative bundling networks with geometrically varied layouts, and points out how these networks perform in terms of vehicle scale, frequency and door-to-door time. The analysis focuses on intermodal transport in Europe, especially intermodal rail transport, but is in search for generic conclusions. The paper does not incorporate the distance and time results in cost models, and draws conclusions for transport innovation, wherever this is possible without cost modelling. For instance, the feature vehicle scale, an important factor of transport costs, is analysed and discussed.Distance and time are important factors of competitiveness of intermodal transport. They generate (direct) vehicle costs and – via transport quality – indirect costs to the customers. Clearly direct costs/prices are the most important performance of the intermodal transport system. The relevance of quality performances is less clarified. Customers emphasise the importance of a good match between the transport and the logistic system. In this framework (time) reliability is valued high. Often transport time, arrival and departure times, and frequency have a lower priority. But such conclusions can hardy be generalised. The range of valuations reflects the heterogeneity of situations. Some lack of clarity is obviously due to overlapping definitions of different performance types.The following parts of the paper are about two central fields of network design, which have a large impact on transport costs and quality, namely the design of vehicle roundtrips (and acceleration of transport speed) and the choice of bundling type: do vehicles provide direct services or run in what we call complex bundling networks? An example is the hub-and-spoke network. The objective of complex bundling is to increase vehicle scale and/or transport frequency even if network volumes are restricted. Complex bundling requires intermediate nodes for the exchange of load units. Examples of complex bundling networks are the hub-and-spoke network or the line network.Roundtrip and bundling design are interrelated policy fields: an acceleration of the roundtrip speed, often desirable from the cost point of view, can often only be carried out customer friendly, if the transport frequency is increased. But often the flow size is not sufficient for a higher frequency. Then a change of bundling model can be an outcome.Complex bundling networks are known to have longer average distances and times, the latter also due to the presence of additional intermediate exchange nodes. However, this disadvantage is – inside the limits of maximal vehicle sizes – overruled by the advantage of a restricted number of network links. Therefore generally, complex bundling networks have shorter total vehicle distances and times. This expression of economies of scale implies lower vehicle costs per load unit.The last part of the paper presents door-to-door times of load units of complex bundling networks and compares them with unimodal road transport. The times of complex bundling networks are larger than that of networks with direct connections, but nevertheless competitive with unimodal road transport, except for short distances.  相似文献   
24.
This paper analyzes energy intensities of ships, diesel–fuelled railways, trucks, and aircraft, using publicly available data. The analysis suggests that differences in operation, not technology, explain most of the variation in energy intensity within and across modes. Among the operational characteristics, most important is the amount of cargo weight transported per vehicle and therefore the scale of the respective transportation system. It is found that each mode has a characteristic envelope in an average energy intensity versus average cargo weight diagram, and estimates of the elasticities of energy intensity with respect to load size are made.  相似文献   
25.
分别介绍单台面静态衡、双台面静态衡和双台面动态衡、三台面动态衡的结构、原理,以及计量不同换长铁路罐车液态质量的方法,简述静态衡、动态衡的检定方法。  相似文献   
26.
Stated choice surveys are used extensively in the study of choice behaviour across many different areas of research, notably in transport. One of their main characteristics in comparison with most types of revealed preference (RP) surveys is the ability to capture behaviour by the same respondent under varying choice scenarios. While this ability to capture multiple choices is generally seen as an advantage, there is a certain amount of unease about survey length. The precise definition about what constitutes a large number of choice tasks however varies across disciplines, and it is not uncommon to see surveys with up to twenty tasks per respondent in some areas. The argument against this practice has always been one of reducing respondent engagement, which could be interpreted as a result of fatigue or boredom, with frequent reference to the findings of Bradley and Daly (1994) who showed a significant drop in utility scale, i.e. an increase in error, as a respondent moved from one choice experiment to the next, an effect they related to respondent fatigue. While the work by Bradley and Daly has become a standard reference in this context, it should be recognised that not only was the fatigue part of the work based on a single dataset, but the state-of-the-art and the state-of-practice in stated choice survey design and implementation has moved on significantly since their study. In this paper, we review other literature and present a more comprehensive study investigating evidence of respondent fatigue across a larger number of different surveys. Using a comprehensive testing framework employing both Logit and mixed Logit structures, we provide strong evidence that the concerns about fatigue in the literature are possibly overstated, with no clear decreasing trend in scale across choice tasks in any of our studies. For the data sets tested, we find that accommodating any scale heterogeneity has little or no impact on substantive model results, that the role of constants generally decreases as the survey progresses, and that there is evidence of significant attribute level (as opposed to scale) heterogeneity across choice tasks.  相似文献   
27.
目前在铁路上广泛使用的有T6D,T6F,T7等型号的检衡车,而T7型检衡车在静态轨道衡计量检定工作中得到广泛应用,本文从影响检衡车标称值的角度浅谈其复现性和使用维护应该注意的事项。  相似文献   
28.
针对JJG234—1990《动态称量轨道衡》的计量性能修订建议,使用规定的检定条件﹑检定方法对若干台自动轨道衡进行试验分析,处理试验的数据,分析试验结果,用试验数据证明试验方法的可行性。  相似文献   
29.
对城市轨道交通线网规划进行了研究,重点分析了几个对线网规划总体效果影响比较大的因素:城市轨道交通客流规模预测的分析;城市轨道交通线网规模的确定;城市轨道交通换乘结点的设置与合理分布。总结了如何合理有效地完善城市轨道交通线网并以此来发挥城市轨道交通大量、快速、公交化的优势,缓解和改善城市的交通压力。  相似文献   
30.
介绍中俄贸易中口岸站轨道衡检测的法律和技术依据,介绍中俄口岸站宽轨道动态轨道衡检测的现场计量方案和检测过程,提出中俄双方应该进一步完善检测体系的建议。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号