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   51篇
  免费   0篇
公路运输   6篇
综合类   1篇
水路运输   30篇
综合运输   14篇
  2018年   1篇
  2017年   1篇
  2014年   1篇
  2013年   19篇
  2012年   2篇
  2009年   1篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  2001年   1篇
  1997年   3篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1989年   1篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1978年   1篇
  1977年   3篇
  1973年   4篇
排序方式: 共有51条查询结果,搜索用时 218 毫秒
31.
The recent breakupof the former Soviet Union and the Russian Republic's movement towards a market economy wil require a considerable improvement and expansion of present port facilities in order to handle increasing cargo throughputs effectively. The Russian Far East is expected to increase trade dramatically through imports of foreign goods, exors of natural resources from Siberia and container traffic traversing teh Trans-Siberian landbridge. The ports of the region will be competing with each other to atract foreing investment and to increase central government assistance in order to facilitate development. This article examines;(1) the more important ports of the Far East and the problems they face as they compete to atract investment; (2) the establishment of a Regional Port Authority as a possible management alternative; (3)advantages of a Port Authority in developing the region' ports and fostering future growth. By analysing these data, a management and development strategy can be formulated for the optimum utilization of present resources and the benefi of reginal modernization and development.  相似文献   
32.
Injuries to natural resources from the release of hazardous substances into aquatic environments have led to hundreds of millions of dollars in compensatory damages awarded under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and other legislation. The institutional mechanisms for negotiating and carrying out the terms of CERCLA natural resource settlements are still in their infancy, and each case has a unique set of injuries, assigned damages, payout schedules, trustee council membership and operating procedures, and environmental conditions and constraints. One of the settlements that has made significant progress toward large‐scale habitat enhancement has occurred in Elliott Bay, a busy, seriously impacted urban harbor in Washington State. The Elliott Bay case is unique among natural resource injury settlements because of the active involvement of two local governments, the City of Seattle, and Metro, who were named as defendants in a lawsuit brought by the National Oceanic and Atmospheric Administration (NOAA) on behalf of the natural resource trustees of Elliott Bay. Both local governments have maintained, and continue to operate, outfalls that discharge into Elliott Bay, and both entities were subject to attempts to recover damages under CERCLA. Following the filing of the lawsuit over injuries to the natural resources of the estuary, alleged to have resulted from the operation of these outfalls, the parties involved negotiated a consent decree settlement. The Elliott Bay/Duwamish Restoration Program has established a process to redress some of the injuries that were attributed to the operation of these outfalls.  相似文献   
33.
Abstract

An analysis of ecological systems that both sustain and are sustained by coastal waters provides the key to a biophysical procedure for delineating inland coastal management boundaries. This analysis entails two basic tasks: (1) mapping the ecosystems that compose coastal waters and adjacent areas, and (2) charting sustaining flows among these systems. The resulting boundary encompasses all environments of coastal waters (subaqueous areas containing a measurable quantity of seawater) and all shore‐lands (either emergent or submergent environments that interchange sustaining materials, energy, or biota with coastal waters). As this biophysical procedure depends on the precise location of, and functional transfers among, coastal ecosystems, it provides a means both for assessing the consequences of human actions and for establishing a landward boundary for a management program. Alternative boundaries not based on locations and operations of coastal ecosystems would probably be either arbitrary or of undue extent, nor would such “alternative”; boundaries be an integral part of an ongoing management process.  相似文献   
34.
This paper reviews the economic literature relating to aviation safety; analyzes the safety record of commercial passenger aviation in the United States and abroad; examines aviation security as a growing dimension of aviation safety; and identifies emerging issues in airline safety and challenges for aviation safety research. Commercial airline safety has improved dramatically since the industry's birth over a century ago. Fatal accident rates for large scheduled jet airlines have fallen to the level where (along many dimensions) aviation is now the safest mode of commercial transportation. However, safety performance has not been evenly distributed across all segments of commercial aviation, nor among all countries and regions of the world. The finding that developing countries have much poorer safety records has been a persistent conclusion in aviation safety research and continues to be the case. Unfortunately, operations data are not available for many of the airlines that experience fatal accidents, so it is not possible to calculate reliable fatality rates for many segments of the worldwide aviation industry. Without more complete information, it will likely be difficult to make substantial improvements in the safety of these operations. Challenges to improving aviation security include: how much to focus on identifying the terrorists as opposed to identifying the tools they might use; determining how to respond to terrorist threats; and determining the public versus private roles in providing aviation security. The next generation of safety challenges now require development and understanding of new forms of data to improve safety in other segments of commercial aviation, and moving from a reactive, incident-based approach toward a more proactive, predictive and systems-based approach.  相似文献   
35.
Shipbuilding is the subject of public policies in a number of countries, as it is considered a strategic industry and has an impact on employment levels in many regions. Establishing performance targets can be a challenge to shipbuilding policy makers. This paper suggests an approach to this problem, based on the Data Envelopment Analysis (DEA) technique. This approach makes it feasible to estimate productivity and building time potential, taking into account the output pattern, technological level and quality of the industrial environment of the country or region. The methodology is applied to the analysis of the competitive potential of some Brazilian shipyard models. The benchmarking analysis was carried out for a sample of shipyards from the world's principal shipbuilding blocks.  相似文献   
36.
The performance of signalized arterials is related to queuing phenomena. The paper investigates the effect of transitional traffic flow conditions imposed by the formation and dissipation of queues. A cross-recurrence quantification analysis combined with Bayesian augmented networks are implemented to reveal the prevailing statistical characteristics of the short-term traffic flow patterns under the effect of transitional queue conditions. Results indicate that transitions between free-flow conditions, critical queue conditions that exceed the detector’s length, as well as the occurrence of spillovers impose a set of prevailing traffic flow patterns with different statistical characteristics with respect to determinism, nonlinearity, non-stationarity and laminarity. The complexity in critical queue conditions is further investigated by introducing two supplementary regions in the critical area before spillover occurrence. Results indicate that the supplementary information on the transitional conditions in the critical area increases the accuracy of the predictive relations between the statistical characteristics of traffic flow evolution and the occurrence of transitions.  相似文献   
37.
就美国交通的基本情况、发展模式、交通工具的选择和新技术的应用、智能交通系统及私有化和外包等诸多方面进行了深入的探讨,对美国交通的发展趋势做出了详尽而有理有据的预测,这样的综合介绍无疑会使我国的交通规划与发展颇受裨益。  相似文献   
38.
39.
So far in the decade of the 1970's, commitments have been made to construct a second generation of new rail systems in four urban areas — Atlanta, Baltimore, Miami and Buffalo. In this paper the authors speculate on the prospects and perils that lie ahead for these systems in the context of national and local expectations for rail transit and the experience of the first generation rail transit systems of San Francisco (BART) and Washington.  相似文献   
40.
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