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   310篇
  免费   0篇
公路运输   69篇
综合类   4篇
水路运输   110篇
铁路运输   6篇
综合运输   121篇
  2022年   1篇
  2019年   5篇
  2018年   3篇
  2017年   12篇
  2016年   7篇
  2015年   6篇
  2014年   3篇
  2013年   58篇
  2012年   4篇
  2011年   6篇
  2010年   19篇
  2009年   21篇
  2008年   22篇
  2007年   23篇
  2006年   12篇
  2005年   6篇
  2004年   6篇
  2003年   4篇
  2002年   5篇
  2001年   2篇
  2000年   4篇
  1999年   3篇
  1998年   3篇
  1997年   3篇
  1996年   7篇
  1995年   7篇
  1994年   1篇
  1993年   6篇
  1992年   4篇
  1991年   4篇
  1990年   3篇
  1988年   2篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1983年   2篇
  1982年   3篇
  1981年   4篇
  1979年   4篇
  1978年   2篇
  1977年   3篇
  1976年   7篇
  1975年   4篇
  1974年   1篇
  1973年   1篇
  1972年   2篇
排序方式: 共有310条查询结果,搜索用时 15 毫秒
231.
The abolition of the national Dock Labour Scheme presented with the oppurtunity radically to transform their cargo handling operations. Port employers have seized this oppurtunity and introduced radical changes to workforce compositions, their skills, work practices, and employee relations. The main factor behind these changes has been the desire of operation to minimize labour costs and maximize labour utilization in order to amintain traffic volume and competitive advantage. The short-term effect has been to improve productivity and profitablity(at least for the major port authorities), but it has also produced iinstablity in employee relations ans may in the long term prove counter productive>  相似文献   
232.
Travel demand models implicitly assume that people respond to changes in a continuous way. This is in contrast to the physical sciences, where discontinuous response is a common phenomenon and is embodied in such concepts as sub-critical and supercritical states.Recent studies have shown that responses to transport policies differ in degree and kind according to the nature and severity of the stimulus and the types of people affected. Response patterns may be categorised by the extent to which they involve adjustments to spatio-temporal or inter-personal linkages. This paper identifies four response domains, with a further distinction between permissive and forced changes.Most travel demand models are designed to operate within an independent, forced (and to a less extent independent permissive) domain and their forecasts become unreliable when responses lie outside that domain. Conversely, a model designed for a more complex domain is unnecessarily cumbersome where simpler responses apply. This paper describes the types of model which are appropriate for each domain and discusses how the effects of a policy may be assigned to the correct domain(s).  相似文献   
233.
The optimal spectral decomposition (OSD) method is used to reconstruct seasonal variability of the Black Sea horizontally averaged chlorophyll-a concentration from data collected during the NATO SfP-971818 Black Sea Project in 1980–1995. During the reconstruction, quality control is conducted to reduce errors caused by measurement accuracy, sampling strategy, and irregular data distribution in space and time. A bi-modal structure with winter/spring (February–March) and fall (September–October) blooms is uniquely detected and accurately documented. The chlorophyll-a enriched zone rises to 15 m depth in winter and June, and deepens to 40 m in April and 35 m in August. The June rise of the chlorophyll-a enriched zone is accompanying by near-continuous reduction of upper layer maximum chlorophyll-a concentration.  相似文献   
234.
The employment and management policies of the shipping industry are in legal and administrative confusion. The shipping industry is struggling with an unworkable global governance based on flag state sovereignty and a sanctionless international regulatory regime. Seafarers suffer most from this state of affairs, but so do the shipping industry’s public image. Few co-operatives of maritime workers exist in national or international shipping. A new employment theory is long overdue. Human centred management policies can only attain their full potential through co-operative or mutual associations. This paper describes the application of enlightened and socially conscious management principles to the shipping industry. Seafarers’ co-operatives are the future organisational building blocks of the shipping industry. Co-operatives can rescue maritime workers from developing countries from exploitation and the debilitating effects of casual labour by providing “all in one” seagoing and shore based professional careers. Seafarers’ co-operatives can solve the shipping industry’s maritime training and education problems. The seven universal principles of co-operative management will guide shipping management in setting human centred objectives that command respect of those who come in contact with the shipping industry.  相似文献   
235.
This article presents an overview of trends relevant for the long-term development of Rotterdam's port complex and resulting opportunities for this complex. These trends resulted from a literature review and conversations with 20 professors in fields relevant for port development. Nine trends that can be expected to become increasingly important in the next decades are discussed. These trends include the rise of manufacturing and logistics platforms, higher land efficiency, increasingly mixed land use in port areas, and rising importance of a “regional innovation system” in ports. Opportunities and concerns for the port of Rotterdam resulting from the trends are discussed.  相似文献   
236.
漫漫长路     
航运公司正寻求能规避巴拿马运河和苏伊士运河通行费的替代方案。  相似文献   
237.
Some South African cities have initiated public transport transformation projects which, in most cases, ultimately envisage the in toto replacement of paratransit operations with formalised BRT systems. There are two likely outcomes: (1) complex negotiations with existing operators and budget constraints will result in the in toto transformation occurring over an extended period of time; or (2) in toto transformation will simply not occur. In either case, cities will depend, for decades, on a ‘hybrid’ public transport system that combines both formal and paratransit operators. This paper presents a case for policy recognition of hybrid systems, and explores how such systems might best be managed. The following categories of hybrid public transport systems are explored through case studies: (1) transformative processes in which paratransit operators are to form or assimilate into companies to operate new services, but this incorporation has proved difficult to complete and the operational and regulatory frameworks remain unchanged; and (2) transformative processes that, from the outset, anticipated a hybrid system and designed the outcome accordingly. A third category of hybrid transport systems, defined as transformative processes that have been amended following a realisation that in toto transformation is unattainable, is also introduced and discussed. The paper concludes by tentatively drawing lessons for appropriate public transport regulation, particularly with respect to Cape Town's transformation project. It is argued that a review of the current national regulatory framework is required to enable possible project modifications that acknowledge system hybridity. It is suggested that regulatory frameworks that accommodate the likely hybrid nature of public transport system outcomes have greater prospects of success than frameworks that do not. Furthermore, it is argued that contextually appropriate and successful public transport transformation projects do not necessarily require the in toto substitution of incumbent paratransit operators, and that they can be integrated with, and complement, formal services.  相似文献   
238.
A review of seven large landlord port authorities around the world reveals a notable diversity of pricing structures. While port authorities increasingly act as commercial undertakings, port pricing often seems to be not driven by commercial considerations. In this paper, we argue that ports can be regarded as “business ecosystems” with multiple users. This provides a valuable perspective on pricing and raises the question of whether ports can be regarded as two-sided markets. We argue this is not the case. The business ecosystem perspective provides a basis for deducing seven pricing principles for port authorities that are detailed in the paper and illustrated with cases these principles. These pricing principles are broadly follow a direct user pays approach; capture value from “non-core” tenants; price aggressively for activities with a high strategic value; differentiate pricing based on price elasticity and connectivity improvements; maximize revenue from long-term lease agreements, price port dues competitively; critically consider differentiation of charges based on environmental performance; and finally use incentives to align interests of terminal operators and shipping lines. We conclude that the ecosystem perspective is central to the understanding of pricing decisions of port authorities and that various pricing issues deserve more attention.  相似文献   
239.
Onboard decision support systems (DSS) are used to increase the operational safety of ships. Ideally, DSS can estimate future ship responses within a time scale of the order of 1–3 h taking into account speed and course changes, assuming stationary sea states. In principle, the calculations depend on a large amount of operational and environmental parameters, which will be known only in the statistical sense. The present paper suggests a procedure to incorporate random variables and associated uncertainties in the calculations of the outcrossing rates that are the basis for risk-based DSS. The procedure is based on parallel system analysis, and the paper derives and describes the main ideas. The concept is illustrated by an example, where the limit state of a non-linear ship response is considered. The results from the parallel system analysis are in agreement with corresponding Monte Carlo simulations. However, the computational speed of the parallel system analysis proved slower than expected.  相似文献   
240.
The Northwest Passage: A simulation   总被引:1,自引:0,他引:1  
We model shipping through the Northwest Passage in northern Canada in order to see if reported recent ice thinning has made this route economic relative to the Panama Canal. Container shipping between Yokohama to New York and St. Johns, Newfoundland is simulated by VSLAM for the two routes using bluewater ships for the Panama Canal and identically sized Canadian Arctic Class 3 (CAC3) ships for the Northwest Passage. Each route is broken into a series of logical legs, and environmental conditions and wait times are assigned. Ice conditions are modeled from historical records. Average speed through the Northwest Passage shows little seasonal variation. Round trips per year are higher through the Northwest Passage. The required freight rate (RFR) to recover all costs including capital recovery is calculated. RFR is slightly lower for the St. Johns to Yokohama transit using the Northwest Passage, and higher for the New York to Yokohama route, as compared to the Panama Canal. Possible future thinning of Arctic ice would further improve the economics of the Northwest Passage.  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