全文获取类型
收费全文 | 2544篇 |
免费 | 25篇 |
专业分类
公路运输 | 781篇 |
综合类 | 348篇 |
水路运输 | 603篇 |
铁路运输 | 245篇 |
综合运输 | 592篇 |
出版年
2024年 | 7篇 |
2023年 | 28篇 |
2022年 | 58篇 |
2021年 | 41篇 |
2020年 | 44篇 |
2019年 | 40篇 |
2018年 | 74篇 |
2017年 | 67篇 |
2016年 | 125篇 |
2015年 | 43篇 |
2014年 | 93篇 |
2013年 | 312篇 |
2012年 | 136篇 |
2011年 | 179篇 |
2010年 | 154篇 |
2009年 | 150篇 |
2008年 | 141篇 |
2007年 | 111篇 |
2006年 | 108篇 |
2005年 | 89篇 |
2004年 | 36篇 |
2003年 | 20篇 |
2002年 | 25篇 |
2001年 | 39篇 |
2000年 | 48篇 |
1999年 | 24篇 |
1998年 | 31篇 |
1997年 | 24篇 |
1996年 | 31篇 |
1995年 | 36篇 |
1994年 | 13篇 |
1993年 | 20篇 |
1992年 | 15篇 |
1991年 | 19篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 15篇 |
1985年 | 21篇 |
1984年 | 12篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1975年 | 11篇 |
1973年 | 8篇 |
排序方式: 共有2569条查询结果,搜索用时 0 毫秒
321.
简要分析了影响内河船舶下沉量的主要因素,介绍了国内外关于船舶下沉量的研究概况及相关近似计算公式.根据Ⅲ级航道船舶下沉量测试物理模型试验结果,提出了适合内河限制性Ⅲ级航道的船舶下沉量近似计算公式.计算结果与模型试验结果对比表明,该公式达到了较高的计算精度,对航道水深计算及航道断面设计具有重要的参考价值. 相似文献
322.
The new Dutch shipping policy has given rise to high expectation and curiosity in the world of shipping. This, together with the obvious difficulties of an ex-post study of the effectiveness of such innovative policy, has prompted the authors to take an interest in attempting to investigate changes in ownership of the Dutch fleet 2 years after the new policy has been introduced. To do this, a rather new concept of ‘flagging out’ has been adopted, which is interpreted as a process leading to different degrees of ‘foreignness’ in a shipping operation. In this paper, a method to structure is presented, and ownership information, and changes in it are presented, that are essentially based on the theory of stochastic processes. The data used is the Dutch fleet data, which includes information on the nationality of the flag, parent ownership and management over the period 1994–1998. The results yield interesting insights in the shifts in the ownership and operational structure of shipping companies induced by the new policy. In particular, they allow one to establish the origin of new vessels, in which stage of ownership/operation it is most likely that shifts occur, and to determine the relationship between the different stages of the ‘flagging out’ process. These results, thus, enable an evaluation of the areas in which the policy can be expected to yield results. 相似文献
323.
Magnus S. Eide Øyvind Endresen Rolf Skjong Tore Longva Sverre Alvik 《Maritime Policy and Management》2013,40(4):367-384
International shipping is a significant contributor to global greenhouse gas (GHG) emissions, and is under mounting pressure to contribute to overall GHG emission reductions. There is an ongoing debate regarding how much the sector could be expected to reduce emissions and how the reduction could be achieved. This paper details a methodology for assessing the cost-effectiveness of technical and operational measures for reducing CO2 emissions from shipping, through the development of an evaluation parameter called the Cost of Averting a Tonne of CO2-eq Heating, CATCH, and decision criterion, against which the evaluation parameter should be evaluated. The methodology is in line with the Intergovernmental Panel on Climate Change (IPCC) and with regulatory work on safety and environmental protection issues at the International Maritime Organization (IMO). The results of this study suggest that CATCH <50 $/tonne of CO2-eq should be used as a decision criterion for investment in emission reduction measures for shipping. In total, 13 specific measures for reducing CO2 emissions have been analysed for two selected case ships to illustrate the methodology. Results from this work shows that several measures are cost effective according to the proposed criterion. The results suggest that cost effective reductions for the fleet may well be in the order of 30% for technical measures, and above 50% when including speed reductions. The results of this study show that the cost effectiveness approach for the regulation of shipping emissions is viable and should be pursued in the ongoing regulatory process. 相似文献
324.
L. R. Roueche 《Maritime Policy and Management》2013,40(1):19-29
In this paper, in which the author attempts to redress the lack of attention by economists to ferry operation, a simple pricing model, based on marginal cost pricing, is developed. 相似文献
325.
The International Maritime Organisation is currently working on establishing regulations for international shipping regarding greenhouse gas emissions, and a cost-effectiveness approach has been suggested as one method for determining the necessary reductions in emissions from shipping. Previous studies have investigated the CO2 emission reduction potential for the world shipping fleet up to 2030 and the associated marginal abatement cost levels. To analyse the cost implications of different emission reduction scenarios, this study has calculated the emission reduction potential and additional capital expenditure for 25 CO2 emission reduction measures applied to 59 ship segments. The expected fleet development over time, keeping track of new ships built from 2010 to 2030 and Existing ships built prior to 2010 and still in operation by 2030, have been modelled. Two alternative approaches to find the cost-effective potential in the world shipping fleet have been applied. One approach is to implement only measures which in themselves are cost-effective (measure-by-measure), and another approach is to implement measures as long as the net savings from cost-effective measures balance the costs of non-cost-effective measures (set of measures). The results demonstrate that by 2030, the majority (93%) of the reduction potential will be related to new ships. Our results show that the measure-by-measure approach would decrease the CO2 emissions by 30% for new ships while the set-of-measures approach with 53% (of the 2030 baseline emissions of 1316?Mt). The implication of achieving such emission reduction is an increase in the capital expenditure on New ships by 6% (USD 183 billion) and 27% (USD 761 billion), respectively, in the period 2010 to 2030 compared to a business-as-usual scenario. The measure-by-measure approach yields a 5% decrease in CO2 emission per 1% increase in capital expenditure, while the set-of-measures approach yields a 2% decrease per 1% increase. This is due to the significant variation in capital intensity of the different measures, ranging from almost zero to USD 200 per tonne of CO2 averted. The results of this study are useful for the shipping industry to assess the economic burden that must be shouldered in order to implement abatement measures under different CO2 emission reduction scenarios. 相似文献
326.
The shipping industry operates in a regulatory framework, where the International Maritime Organization (IMO) is the leading regulatory body. The role of the IMO is to propose maritime regulations to its member states. The successful worldwide implementation of a maritime regulation depends on how many member states adopt it. However, many maritime regulations are not adequately implemented worldwide. As a result, ship operators have found themselves in an uncomfortable position in developing their business in an unstable regulatory regime. This paper proposes an extendable and applicable methodology involving a System of Hierarchical Scorecards (SHS) to measure the implementation costs and benefits of a newly introduced or existing maritime regulation by ship operators. The regulators may use the results in evaluating newly introduced and/or existing regulations through taking into account the economic burden that will be generated to ship operators. In this paper, SHS is extended to demonstrate its applicability on evaluating a ship operator’s organization with regard to his regulatory implementation performance by the means of a case study. 相似文献
327.
Shobha S. Das 《Maritime Policy and Management》2013,40(2):111-128
Intense competition in many sectors across the maritime industry and in professional ship management in particular, means that the quest for achieving competitiveness will continue and intensify. A review of the current strategies across many sectors of the industry indicates the importance of forging stable partnerships for the achievement of competitiveness. Considering that the capability to form a relationship is an intangible resource (as depicted in resource-advantage theory), an empirical assessment in the context of ship management was undertaken. The assessment aimed to identify the type of relationships present in ship management, and succeeded in classifying those relationships into four distinct groups. The central thesis of the paper is that maritime organizations in general, and ship management companies in particular, may utilize their intangible relational resources in order to achieve competitive advantage. Based on the classification of ship management relationships, implications for managers are discussed. 相似文献
328.
ABSTRACTHow vessel crews perceive safety on board (shipboard safety) is a useful indication for the general safety level. In this study a theoretical model was explored, involving factors that could possibly influence shipboard safety. Based on a survey questionnaire (n = 244), safety climate, shipowner efficiency demands and regulatory activities were investigated as influencing factors. Structural equation modelling gave support to the theoretical model and the findings illustrate that simultaneous involvement of various levels of the maritime system (crews, shipowners, regulators) can be effective for safety improvements. The study indicates that shipboard safety is affected by actions and prioritization by external actors through safety climate. It suggests that the maritime industry will profit from monitoring safety climate as part of the ongoing risk considerations, as a supplement to reactive parameters such as accident statistics. 相似文献
329.
The purpose of this article is to evaluate the service requirements of dedicated container terminals (DCTs). In this article, the service attributes (SAs) of DCTs were first discussed. A fuzzy analytic hierarchy process model was then constructed to measure the users’ perceived importance and dissatisfaction for each of the SAs. Based on these two measurements, a revised importance-performance analysis model was proposed to identify the SAs that should be improved. To validate the model, the dedicated container terminal of Evergreen Marine Corp. (EMC DCT) at Kaohsiung Port and its users were empirically investigated. With respect to the empirical results, managerial implications of the findings in improving service quality for the EMC DCT are discussed. 相似文献
330.
Michael Lück 《Coastal management》2016,44(2):131-138
With the continuing growth of the tourism industry over recent decades, has come a change in tourist behavior from the traditional stereotypical 3-S tourist (sun, sand, sex) to an increasingly sophisticated and demanding tourist. These “new” tourists like to learn about history, nature, and wildlife, and they expect an educational component on wildlife tours. This study investigated swim-with-dolphin tours in Kaikoura, New Zealand with regard to the educational content and the overall anatomy of these tours, using data from observations on a total of 32 tours during December 2011. The resulting data were then compared with the data from Hrycik and Forestell's study, which investigated the content of questions asked by passengers on whale-watching tours in Stellwagen Bank National Marine Sanctuary. Results of the on-tour observations indicate that the surveyed tours display a structured approach to interpretation, which is customized to the specific tour anatomy of a “swim-with” tour, and varies in some parts significantly from “watch-only” tour interpretation. 相似文献