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   36篇
  免费   0篇
公路运输   3篇
综合类   3篇
水路运输   13篇
综合运输   17篇
  2019年   1篇
  2018年   2篇
  2017年   1篇
  2014年   1篇
  2013年   7篇
  2012年   3篇
  2011年   3篇
  2010年   2篇
  2009年   1篇
  2008年   2篇
  2007年   1篇
  2002年   1篇
  1998年   4篇
  1996年   1篇
  1995年   1篇
  1989年   1篇
  1985年   2篇
  1979年   1篇
  1976年   1篇
排序方式: 共有36条查询结果,搜索用时 0 毫秒
31.
Abstract

There is a growing phenomenon of grassroots innovation, that is, that triggered by individual users or communities (physical or virtual) seeking a solution to a personal or societal problem. This has great potential as a new source of sustainable transport innovations, but has received little attention to date. This study conducted 16 in-depth interviews and a workshop with grassroots innovators in transport. A detailed thematic analysis of the interview data identified: catalysts for the idea and the motivation behind its pursuit; the barriers experienced (those that were overcome and those that were not); and the enablers that permitted the innovations to continue and to flourish. The paper concludes by identifying the conditions that need to exist for such innovations to be created, developed and exploited in order that their potential for increasing the sustainability of the transport system can be fulfilled.  相似文献   
32.
Although containerization in Third World Asian ports may not conform to the ‘usual’ model of containerization in developed countries the region represents a significant generator of container tonnage. Moreover, despite considerable intra-regional differences in throughput productivities, some of the ports are achieving efficiencies and productivities markedly higher than those in well established ports in Western countries. The region has been characterized, too, by strong patterns of mainline/feeder interdependencies. This paper reviews the status of containerization in Third World Asia and suggests that major changes, reflecting a variety of factors, are likely by 1990.  相似文献   
33.
Based on a public survey of registered voters, we explore four options for internalising the social and environmental costs of road transport. The options were presented together with generalised factual information about their benefits and costs. Respondents are highly supportive of fuel use efficiency standards and exhaust gas quality standards, with lesser support for proposed initiatives of road user charges and speed reduction. Demographic analysis of responses enables identification of those who might favour or oppose particular options. In this case women are identified as being strongly supportive of the speed reduction option.  相似文献   
34.
在过去的一个世纪里,城市交通控制始终在演变,以适应日益复杂的政策目标和不断增长的交通需求。一个高效的交通控制系统可以带来很多收益,例如缓解拥堵、提高经济效益以及改善道路安全和空气质量。车辆检测和通信技术方面取得的显著进步为交通控制系统的调控能力带来了一系列阶段性变化:从早期(固定配时)信号控制发展到现代化的集成系统。多种类型的交通控制系统在全球不同地区建设完成,每种系统都有各自的优势和不足。首先通过对比分析目前占据领先地位的商用系统(以及一些较少为人所知的系统),凸显交通控制系统的关键特征和差异,然后评估目前的交通控制系统是否能实现现代交通政策的职能和需求。最后,探讨了当前及未来的交通政策,以及未来10年交通控制发展的技术性蓝图,指出交通控制有望通过技术进步从有限数据时代迈入大数据时代。  相似文献   
35.
Most analyses of marine microbial systems in the seasonally ice covered areas of the Southern Ocean have been based on data from the major embayment areas of the Ross and Weddell Seas. In this study data were collected at stations covering a range of regimes from full ice cover through to open water in the Bellingshausen Sea. A major feature of the production system was a rapid retreat of the ice-edge, which uncoupled the marginal ice zone from a phytoplankton bloom which remained associated with a frontal system. This bloom was maintained, and probably initiated, in an unusual environment generated by the interaction between the marginal ice zone and the front. Size-based analyses of the microbial system were derived for ice-covered, recently ice-covered and open water sites. Estimates of standing stocks and key rate processes were combined to produce a single food web network for each station. The under-ice system was one of low production and low recycling but apparently high retention. As the ice retreated the microbial systems to the north began to develop, but these were constrained by grazing pressure. The bloom in the area appeared to be sustained even though estimated losses were far higher than production, although the high sedimentation losses expected were not observed. The carbon flow networks are discussed in relation to the environmental changes and the interaction of the marginal ice zone and the frontal system appears crucial to the phytoplankton. Microzooplankton grazing is implicated as a major controlling factor. The local microbial dynamics are strongly influenced by material which was produced at an earlier time and somewhere else in the Southern Ocean.  相似文献   
36.
荷兰国家岩土工程研究所(GeoDelft)近来提出了一个称为SmartSoils的新概念.Smart Soils,意即人们所需要的土,其着眼点在于土的某些性质(如渗水性、刚度和强度),以及如何将它们改良,使之能满足工程建设的某些要求.这些新的技术在岩土工程中可以被广泛应用.  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