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   54篇
  免费   0篇
公路运输   10篇
水路运输   23篇
铁路运输   1篇
综合运输   20篇
  2019年   3篇
  2017年   4篇
  2015年   3篇
  2014年   1篇
  2013年   14篇
  2012年   2篇
  2011年   1篇
  2009年   2篇
  2008年   1篇
  2006年   3篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2001年   1篇
  2000年   2篇
  1998年   1篇
  1995年   1篇
  1992年   1篇
  1991年   2篇
  1989年   2篇
  1985年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1975年   2篇
排序方式: 共有54条查询结果,搜索用时 62 毫秒
31.
印度对于与中国合作的重重顾虑——最初出于安全考虑,印度政府对中国公司在该国电信行业的影响倍感忧虑——如今这种安全忧虑已经蔓延到了港口运输业。Gordon Feller为您报道。[编按]  相似文献   
32.
Factors that influence the magnitude and the depth of the chlorophyll maximum layer in the ocean off Southern California are explored using observations from the long-term California Cooperative Oceanic Fisheries Investigations (CalCOFI) program. The data record is sufficiently long to reveal patterns not always evident from single stations or single cruises. Processes such as coastal wind-driven upwelling, geostrophic circulation, and annual physical and chemical cycles are illustrated to demonstrate their effect on euphotic zone nutrient availability, and subsequent phytoplankton biomass and primary productivity. In this area, where the influence of wind-driven upwelling is spatially restricted and advected waters are generally nutrient depleted, geostrophically induced upwelling and winter convection become important in determining spatial and temporal patterns of phytoplankton.  相似文献   
33.
As theoretical approaches to port development have advanced over the years, the role of the inland terminal has attracted increasing focus, particularly under the framework of port regionalisation. This paper will explore port regionalisation in different contexts through a greater focus on the drivers and direction of a number of inland terminal development strategies.The paper will build on previous work by combining inland terminal taxonomies and the theory of directional development with traditional port development models. Regionalisation strategies will be compared and contrasted through examples derived from field work undertaken in Europe and the USA. The results contribute towards a disaggregation of the process of port regionalisation, revealing different levels of integration and cooperation observed in different location splitting models. In this way, different strategies will be elucidated, enabling further exploration and more nuanced understanding of the institutional aspects of spatial development.  相似文献   
34.
This paper addresses the situation of transport infrastructure in Central America, which poses issues of insufficiency, high-costs and lack of an integrated vision in a geographic region that is exposed to vulnerabilities due to its geological, geomorphologic and climatic conditions. The major efforts for regional integration with joint infrastructure in place seem to meet the criteria of high prioritization on ground transport and non-diversification of risk. This paper features the characteristics of the area and the potentiality of short-sea shipping to cover infrastructure deficits and the need for a more integrated planning of transport infrastructure services with better conditions to improve the regional economy competitiveness and the economic growth.  相似文献   
35.
Restructuring of governmental activities in New Zealand calls for public enterprises to operate in competitive environments. This has created problems for highways and urban passenger transport. Whereas the national airline has been privatized and railways corporatized, legislation for land transport has created a Crown agency that is expected to operate commercially within funding and policy constraints. The problems are assessed as Transit New Zealand attempts to allocate state funds between competing projects using commercial criteria. New roles have been legislated for regional agencies and local governments: they are expected to either privatize service delivery or create public corporations to maintain highways and operate passenger transport. Principles underlying restructuring are examined, and suggestions are made on how agencies might take advantage of opportunities.  相似文献   
36.
37.
Latin America and the Caribbean have evolved as a region of increased interest for the maritime and port industry as well as for academic research. Maritime transport activity in the region has experienced sustained growth rates over the last decades, resulting in ever-increasing demand for maritime services and port infrastructure. At the 2011 Annual Conference of the International Association of Maritime Economists (IAME), Latin America received significant attention. This editorial responds to growing research by giving a brief overview of the current situation and contemporary issues in maritime transport within the region. It also introduces the six selected papers for this Special Issue.  相似文献   
38.
39.
We describe a model that integrates a multiregional input–output (I–O) model of the USA (for 50 States and the District of Columbia) with the national highway network. Inter-state commodity shipments are placed on a congestible highway network. Simulations of major choke-point disruptions redirect traffic which increases the costs of some shipments. Increased costs show up in higher prices which help to determine a new I–O equilibrium. We find economic and network equilibria that are consistent. The simulations show only moderate economic impacts. We ascribe this to the resilience of the highway network. The model provides State-level detail on who bears the costs of the disruptions.  相似文献   
40.
Integrated land use/transportation forecasting models add significant policy and infrastructure alternatives analysis capabilities to the urban planning process. Historically, the financial, time, and staff requirements to develop one of these models has put them beyond the reach of most small- to medium-sized urban areas. The purpose of this paper is to present the large zone economic submodel of SE3M, an integrated model – founded upon economic base theory and bid-rent theory – that is reasonably accurate, yet simpler in form, function, and implementation than competing models. The US territory of Guam is used as the case study/proof of concept implementation for this model framework. The submodel presented here was validated against a horizon year with known data for zonal level population and employment totals together with control totals for the island as a whole. The model was able – across two base years and one validation, horizon year – to locate all jobs and a high percentage of the population on each zone on the island.  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