全文获取类型
收费全文 | 912篇 |
免费 | 9篇 |
专业分类
公路运输 | 234篇 |
综合类 | 35篇 |
水路运输 | 341篇 |
铁路运输 | 32篇 |
综合运输 | 279篇 |
出版年
2022年 | 8篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2017年 | 25篇 |
2016年 | 23篇 |
2015年 | 15篇 |
2014年 | 17篇 |
2013年 | 142篇 |
2012年 | 34篇 |
2011年 | 39篇 |
2010年 | 30篇 |
2009年 | 39篇 |
2008年 | 39篇 |
2007年 | 28篇 |
2006年 | 19篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 24篇 |
2002年 | 8篇 |
2001年 | 11篇 |
2000年 | 20篇 |
1999年 | 11篇 |
1998年 | 15篇 |
1997年 | 17篇 |
1996年 | 22篇 |
1995年 | 28篇 |
1994年 | 5篇 |
1993年 | 14篇 |
1992年 | 17篇 |
1991年 | 10篇 |
1990年 | 13篇 |
1989年 | 5篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 15篇 |
1982年 | 12篇 |
1981年 | 18篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 13篇 |
1974年 | 5篇 |
1973年 | 7篇 |
排序方式: 共有921条查询结果,搜索用时 359 毫秒
301.
302.
Transportation - Based on an analysis of observed automobile routes, an investigation is made into the factors affecting choice of routes. As in previous studies, the attempt to determine the... 相似文献
303.
304.
The aim of this paper is to indicate some of the distinctive problems of executive leadership which surround the control of authority in merchant navy training schools in the United Satates, Great Britain, and Spain. On the basis of extensive field interviews with the staff and directors of two American, three British, and two Spanish, schools, our purpose is to suggest the conditions which give rise to the need for particular kinds of leadership styles, depending upon the manner by which nautical education is organized [1]. More specfi-cally, our thesis is that their organizationl chartering arrangements (defined as contractual and quasi-contractual linkages with variious third parties to nautical education) mandate specific kinds of internal structural patterns within nautical schools which, in turn, produce the need for different styles of executive leadership. 相似文献
305.
Transportation - Weather events often force motorists to drive in unsafe conditions or alter travel plans. Both decisions are imbued with costs that drivers may minimize by developing adaptation... 相似文献
306.
Long-term variability of the biogeochemical properties during the formation of central waters in the Eastern North Atlantic were analyzed between 42–47°N and 10–20°W from the dataset gathered during the Galicia VII (GVII) and C. Darwin 58/59 (CD58/59) cruises. These cruises that showed important changes in the thermohaline properties and the nutrient abundance of the upper layers were carried out under contrasting conditions of the North Atlantic Oscillation (NAO) index. The different climate forcing led a meridional shift of the transition zone between the formation regions of subpolar and subtropical Eastern North Atlantic Central Water (ENACWp and ENACWt, respectively). This displacement conditioned the presence of each ENACW in the study region and so the thermohaline and biogeochemical properties. The effect of the observed variability at decadal scale on the air–sea CO2 gradient (ΔfCO2) and exchange (FCO2) was analyzed using 1D model approach throughout 11 weekly-steps that simulated the development of a spring bloom during the shoaling of the mixed layer. The outputs of the model showed an intensification of the ocean CO2 uptake due to higher biological CO2 drawdown, during positive NAO conditions and its weakening under negative NAO influence. 相似文献
307.
Virginia R. Ferritto 《WMU Journal of Maritime Affairs》2016,15(2):353-380
Presenteeism research has only recently extended from a construct capturing lost productivity due to attending work despite health issues to a construct representing students’ perceived academic performance. Aligning with presenteeism’s prevalent research paradigm, the pioneering studies used health-related issues to measure presenteeism. In contrast, this study used the Presenteeism and Perceived Academic Performance (PPAP) Scale, which the researcher developed for this study. The PPAP Scale comprises aspects of student behavior that support academic performance. This study filled gaps in the literature by investigating presenteeism as a concept associated with students’ perceived academic performance, measured with the PPAP Scale, and factors specific to maritime education. The factors investigated were self-identified by the study respondents, in sufficient numbers to support statistical analysis, as favorably (i.e., cruise and license/maritime instruction) or negatively (i.e., mandatory regimental activity, taps, morning or afternoon formations, and watch) impacting their academic performance. This study found no statistical evidence to suggest the level of presenteeism, measured with the PPAP Scale, among the study’s sample of license students is associated with factors perceived to favorably or negatively impact academic performance. Additional insight can be gained from license student participants’ responses to the study’s open-ended questions (e.g., a perceived imbalance between time available to allocate to their academics and time needed to fulfill regimental responsibilities). 相似文献
308.
Amy R. Campbell Tim Ryley Rob Thring 《Transportation Research Part A: Policy and Practice》2012,46(8):1318-1327
The transport sector has been identified as a significant contributor to greenhouse gas emissions. As part of its emissions reduction strategy, the United Kingdom Government is demonstrating support for new vehicle technologies, paying attention, in particular, to electric vehicles.Cluster analysis was applied to Census data in order to identify potential alternative fuel vehicle drivers in the city of Birmingham, United Kingdom. The clustering was undertaken based on characteristics of age, income, car ownership, home ownership, socio-economic status and education. Almost 60% of areas that most closely fitted the profile of an alternative fuel vehicle driver were found to be located across four wards furthest from Birmingham city centre, while the areas with the poorest fit were located towards the centre of Birmingham. The paper demonstrates how Census data can be used in the initial stages of identifying potential early adopters of alternative vehicle drivers. It also shows how such research can provide scope for infrastructure planning and policy development for local and national authorities, while also providing useful marketing information to car manufacturers. 相似文献
309.
Gunwoo Lee Soyoung You Stephen G. Ritchie Jean-Daniel Saphores R. Jayakrishnan Oladele Ogunseitan 《Transportation Research Part A: Policy and Practice》2012,46(8):1177-1193
In this paper, vehicle microscopic simulation and emission models were combined with an air pollutant dispersion model and a health assessment tool to quantify some social costs resulting from urban freight transportation in the Alameda corridor that links the Ports of Los Angeles and Long Beach to downtown Los Angeles. Traffic on two busy freeways, the I-710 and the I-110, and some heavily trafficked arterial roads was analyzed to estimate the health impacts caused by drayage truck emissions of particulate matter (PM) for four different years: 2005, which serves as a baseline for various pollution inventories, as well as 2008, 2010 and 2012. These years correspond to deadlines for the Clean Truck Program (CTP), which was put in place to improve air quality in the Alameda corridor. Results show that the health costs from particulate matter (PM) emitted by drayage trucks exceeded 440 million dollars in 2005. However, these costs decreased by 36%, 90%, and 96% after accounting for the requirements of the 2008, 2010, and 2012 CTP deadlines. These results quantify the magnitude of the social costs generated by drayage trucks in the Alameda corridor, suggest that these costs justified replacing drayage trucks operating there, and indicate that the Clean Truck Program likely exceeded its target. 相似文献
310.
Transportation - Demand-responsive technologies are rapidly changing the transportation landscape. The City of Belleville, Ontario has recently replaced its evening and nighttime fixed route bus... 相似文献