全文获取类型
收费全文 | 639篇 |
免费 | 5篇 |
专业分类
公路运输 | 139篇 |
综合类 | 22篇 |
水路运输 | 233篇 |
铁路运输 | 19篇 |
综合运输 | 231篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 10篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 21篇 |
2017年 | 12篇 |
2016年 | 23篇 |
2014年 | 17篇 |
2013年 | 113篇 |
2012年 | 28篇 |
2011年 | 31篇 |
2010年 | 21篇 |
2009年 | 25篇 |
2008年 | 25篇 |
2007年 | 22篇 |
2006年 | 13篇 |
2005年 | 19篇 |
2004年 | 9篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 16篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 2篇 |
1977年 | 9篇 |
1976年 | 6篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有644条查询结果,搜索用时 31 毫秒
71.
A. F. Beckenham 《运输评论》2013,33(1):67-74
The review undertaken in this Paper shows how, in 1984, governments of nation‐states of the world deal with the important function of Transport. In all 115 countries are included and, with the information now given, it is possible to compare the situation with 1981–82, and also have a current global view of affairs affecting Transport as managed by governments. Such a review is part of the service which Transport Reviews provides for its readers. It is hoped to conduct a further review in 1988. 相似文献
72.
Abstract The passage of the Marine Plastics Pollution Research and Control Act of 1987 (MPPRCA), which codified Annex V of the International Convention for the Prevention of Pollution from Ships (MARPOL), has encompassed every commercial and recreational shipping and boating facility in the United States. As a group, these ports, harbors, and marinas form a significant, although proportionately small, portion of the coastline of the country. More important, the economic benefits derived from the complex shoreside infrastructures required for international ocean trade, commercial and recreational fishing, and pleasure boating indicate just how critical it is for these facilities to be in conformance with effective and prudent coastal zone and environmental management practices. 相似文献
73.
Olav F. Knudsen 《WMU Journal of Maritime Affairs》2009,8(2):145-172
The short Baltic export route for Russian oil is an attractive source of supply for the European energy market. The article
examines the Russian oil export trade in the Baltic based on Automatic Identification System (AIS) data from 2005 matched
with supplementary data. The first part of the article gives a survey of activities and characteristics of 261 large crude
oil tankers, their flag states and owner countries. The second part views the data in the context of accidental oil spill
risk. Greek and Russian owners are leading carriers in this trade. Russia plays a double leading role as oil exporter and
shipowning country, securing major cargo shares for nationally owned vessels, while also giving a preferential spot in the
trade to Greek owners. Where environmental aspects are concerned, previous research has linked vessel characteristics with
the risk of casualty. Knowledge of flag, age, ownership and activity levels adds useful information about environmental risk.
The data show that flags associated with very high casualty or detention probabilities were represented by 18% of the activity
in this trade. Older vessels have a similar share, and at this particular time probably represent the more serious threat
of accidental oil spills. 相似文献
74.
75.
F. J. GABLE 《Coastal management》2013,41(4):435-456
This article addresses interdisciplinary sustainable aspects of fisheries as part of ocean management. Human-caused impacts and their role as modifiers of living marine resources is discussed. The research note also theorizes about contemporary global change and its prospective biological consequences, especially when coupled with human-induced factors in coastal marine waters. Also addressed is the management and ecological aspects of fish stock populations as part of a large marine ecosystem (LME) in the Northeast United States continental shelf of the Atlantic Ocean with suggestions for an interdisciplinary policy orientation paradigm to foster the sustainability of marine life in the sea. 相似文献
76.
This paper attempts to address the issue of transporting hazardous materials and the question whether this activity constitutes a significant problem on Arizona's low volume roads. Problems related to lack of data required for most of existing risk assessment models are discussed. A preliminary risk assessment, conducted by the use of a screening model, attested that of the total state low volume road mileage, only 30% may need further, and more detailed, hazardous materials transportation risk analysis. The remaining 70% is currently free of any significant risk. 相似文献
77.
Paula C. Pardo Marcos Vázquez-Rodríguez Fiz F. Pérez Aida F. Rios 《Journal of Marine Systems》2011,84(3-4):67-77
This work estimates new regionalized empirical parameterizations for preformed alkalinity (ATo) and the CO2 air–sea disequilibrium (?Cdis). Both are key terms for the computation of anthropogenic CO2 in the back-calculation methods. Data from the subsurface layer (75–180 m depth range) covering an area from North to South and from 19°E to 67.5°W (Pacific and Indian oceans) were taken from GLODAP (The Global Ocean Data Analysis Project) database. The subsurface layer is proved as a reliable reference for representing the main characteristics of the different water masses of the oceans. Besides, handing data from the two ocean basins altogether makes the new parameterizations of ATo and ?Cdis to be more globally consistent. Nevertheless, each ocean basin, at least in some regions, has different oceanographic characteristics based on its proper dynamical processes and water masses formation. In order to maintain each ocean basin ‘identity’ the whole domain was divided in six different regions (two of them sharing waters from Pacific and Indian oceans) and parameterizations in each region for both terms were obtained. Previously, data were transformed into a grid of 4°lat. × 5°lon. and the results obtained from the parameterizations were visualized and compare with pCO2 climatologies. From the comparisons with previous ?Cdis estimations good results are obtained showing the reliability and robustness of the new regionalized empiric parameterizations. 相似文献
78.
79.
Marine ecosystem models are becoming increasingly complex and sophisticated, and are being used to estimate the effects of future changes in the earth system with a view to informing important policy decisions. Despite their potential importance, far too little attention has been, and is generally, paid to model errors and the extent to which model outputs actually relate to real-world processes. With the increasing complexity of the models themselves comes an increasing complexity among model results. If we are to develop useful modelling tools for the marine environment we need to be able to understand and quantify the uncertainties inherent in the simulations. Analysing errors within highly multivariate model outputs, and relating them to even more complex and multivariate observational data, are not trivial tasks. Here we describe the application of a series of techniques, including a 2-stage self-organising map (SOM), non-parametric multivariate analysis, and error statistics, to a complex spatio-temporal model run for the period 1988–1989 in the Southern North Sea, coinciding with the North Sea Project which collected a wealth of observational data. We use model output, large spatio-temporally resolved data sets and a combination of methodologies (SOM, MDS, uncertainty metrics) to simplify the problem and to provide tractable information on model performance. The use of a SOM as a clustering tool allows us to simplify the dimensions of the problem while the use of MDS on independent data grouped according to the SOM classification allows us to validate the SOM. The combination of classification and uncertainty metrics allows us to pinpoint the variables and associated processes which require attention in each region. We recommend the use of this combination of techniques for simplifying complex comparisons of model outputs with real data, and analysis of error distributions. 相似文献
80.
Thomas A. Mensah 《WMU Journal of Maritime Affairs》2004,3(1):17-30
The adoption of the International Ship and Port Facility Security Code (ISPS Code) is the latest response of the international
shipping community to the increasing threat posed by acts of terrorism at sea. The ACHILLE LAURO incident of 1985 showed that
the traditional law against piracy was not adequate to deal with new types of unlawful acts against international shipping,
especially those involving acts of terrorism. The 1988 Convention for the Suppression of Unlawful Acts against the Safety
of Maritime Navigation (SUA Convention) and the technical and administrative measures adopted by the Maritime Safety Committee
of IMO in 1986 and 1996 attempted to develop a broader regime to deal with unlawful acts against international shipping.However,
the events of September 11, 2001 showed that additional measures were still needed to prevent terrorist attacks against ships. 相似文献