全文获取类型
收费全文 | 1045篇 |
免费 | 8篇 |
专业分类
公路运输 | 283篇 |
综合类 | 27篇 |
水路运输 | 331篇 |
铁路运输 | 30篇 |
综合运输 | 382篇 |
出版年
2022年 | 18篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 24篇 |
2017年 | 28篇 |
2016年 | 35篇 |
2015年 | 12篇 |
2014年 | 46篇 |
2013年 | 149篇 |
2012年 | 43篇 |
2011年 | 45篇 |
2010年 | 47篇 |
2009年 | 41篇 |
2008年 | 42篇 |
2007年 | 20篇 |
2006年 | 25篇 |
2005年 | 29篇 |
2004年 | 16篇 |
2003年 | 26篇 |
2002年 | 19篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 21篇 |
1998年 | 32篇 |
1997年 | 24篇 |
1996年 | 18篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 14篇 |
1992年 | 15篇 |
1991年 | 15篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 15篇 |
1984年 | 14篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1974年 | 11篇 |
1972年 | 5篇 |
排序方式: 共有1053条查询结果,搜索用时 15 毫秒
11.
12.
The need to measure and evaluate transit system performance has led to the development of numerous performance indicators. However, depending upon the indicator, we oftentimes reach different conclusions regarding transit system performance. The research reported in this paper uses factor analytic methods to generate a set of underlying attributes (factors) that capture the performance of public transit systems in Indiana. Similar to what is reported in the literature, this study finds three attributes that best describe transit system performance: efficiency, effectiveness, and overall performance. Based upon systemsÕ factor scores, the study finds that systems scoring highly on one attribute generally perform well on the remaining attributes. Further, there is an inverse relationship between system performance and subsidies, a finding that supports performance based subsidy allocations. 相似文献
13.
Barbara E. Baarsma Jan G. Lambooy 《Transportation Research Part D: Transport and Environment》2005,10(6):459-475
Externalities are uncompensated influences that are not expressed in a market but that affect the production possibilities or the welfare level of third parties. An example is the noise pollution in airport areas. Although air transport is an important source of economic growth and employment in many countries, the social and environmental problems connected with this sector are rising rapidly. Consequently, airports are becoming a matter of concern to many politicians. On what kind of values should they base their decisions as to further growth or consolidation of the current situation? In this paper we discuss two approaches, one based on mainstream, neo-classical, economics, and one based on institutional approaches, more in particular new institutional economics, which can be seen as a development complementary to the mainstream. 相似文献
14.
The Agulhas Current with its retroflection and attendant eddy-shedding is the cause of some of the greatest mesoscale variability in the ocean. This paper considers the area to the south and east of Madagascar, which provides some of the source waters of the Agulhas Current, and examines the propagating sea surface height signals in altimetry and output from a numerical model, OCCAM. Both show bands of variability along the axis of the East Madagascar Current (EMC) and along a zonal band near 25°S. Sequences of images plus associated temperature data suggest that a number of westward-propagating eddies are present in this zonal band. The paper then focuses on the region to the south of the island, where ocean colour and infra-red imagery are evocative of an East Madagascar Retroflection. The synthesis of data analysed in this paper, however, shows that remotely observed features in this area can be explained by anticyclonic eddies moving westward through the region, and this explanation is consistent with numerical model output and the trajectories of drifting buoys. 相似文献
15.
16.
The focus of this paper is the degree to which day-to-day variability in the individual's travel pattern has a systematic, or nonrandom, component. We first review the different sources of variability in travel, emphasizing the difference between between-individual and within-individual variation and the implications of this difference for travel analysis. After discussing the impact of measurement (i.e. the way in which travel behavior is measured) on the study of repetition and variability, we use the Uppsala data to examine the level of systematic variability in an individual's longitudinal travel record. The analysis focuses on two questions: - How well does observation over one week capture longer-term (five-week) travel behavior; in other words, is behavior highly repetitive from week to week? - How systematic is within-individual variability; in other words, are certain stops distributed over the five-week record in a nonrandom, that is either regular or clustered, fashion? Using measures of travel that include more than one stop attribute (e.g. activity, mode, time of day, and location), we found that: - A seven-day record of travel does not capture most of the separate behaviors exhibited by the individual over a five-week period, but it does capture, for most people, a good sampling of the person's different typical daily travel patterns. - Whereas a considerable portion of intraindividual variability is systematic (nonrandom), clustering is a more important source of nonrandom variation than is regularity. The results suggest that behavior does not follow a weekly cycle closely enough for a one-week travel record to measure the longer-term frequency with which the individual makes certain stops or to assess the level of day-to-day variation present in the individual's record. Because these results are likely to reflect the particular measures of behavior we used, one conclusion of this study is the need for other studies that replicate the aims of this one but use a variety of other travel measures. Only through such additional work can we truly assess the sensitivity of our findings to measurement techniques. 相似文献
17.
This is the second of two background papers sponsored for the Symposium by the Administrative Commission for the north of the Netherlands. Its purpose is to provide an indication of the effects of the proposed high speed rail line between Amsterdam, Groningen and Hamburg on employment in the corridor. The authors first review the techniques of forecasting these effects discussed in the literature. The potentials approach is adopted for their analysis, the mathematics and underlying assumptions of which are presented. Finally, this model is run to provide an estimate of the impact on regional employment of three variants of the proposed rail line. 相似文献
18.
19.
In this introduction to the special issue on habitual travel choice, we provide a brief account of the role of habit in travel behaviour, discuss more generally what habitual choice is, and briefly review the issues addressed in the solicited papers. These issues include how habitual travel behaviour should be measured, how to model the learning process that makes travel choice habitual, and how to break and replace car-use habits. 相似文献
20.