全文获取类型
收费全文 | 912篇 |
免费 | 8篇 |
专业分类
公路运输 | 221篇 |
综合类 | 38篇 |
水路运输 | 339篇 |
铁路运输 | 32篇 |
综合运输 | 290篇 |
出版年
2022年 | 8篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 14篇 |
2017年 | 23篇 |
2016年 | 21篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 147篇 |
2012年 | 34篇 |
2011年 | 43篇 |
2010年 | 30篇 |
2009年 | 38篇 |
2008年 | 40篇 |
2007年 | 27篇 |
2006年 | 16篇 |
2005年 | 21篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 8篇 |
2001年 | 11篇 |
2000年 | 21篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 18篇 |
1996年 | 21篇 |
1995年 | 26篇 |
1994年 | 5篇 |
1993年 | 14篇 |
1992年 | 17篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 5篇 |
1988年 | 14篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1984年 | 7篇 |
1983年 | 16篇 |
1982年 | 13篇 |
1981年 | 18篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 13篇 |
1974年 | 6篇 |
1973年 | 7篇 |
排序方式: 共有920条查询结果,搜索用时 843 毫秒
751.
Daniel J. Mayor Thomas R. Anderson David W. Pond Xabier Irigoien 《Journal of Marine Systems》2009,78(4):511
The egg production of marine copepods correlates with a range of variables, including the availability of organic carbon (C), nitrogen (N) and the polyunsaturated fatty acids (PUFAs) 20:5(n−3) (EPA) and 22:6(n−3) (DHA). However, an understanding of which substrates limit egg production in the natural environment has yet to be reached. The quantities of C, N, EPA and DHA ingested, derived from parental biomass, and invested in eggs by female Calanus finmarchicus during a 5-day incubation experiment were examined using stoichiometric theory to determine which substrate was limiting. The majority of each substrate was derived from parental biomass, and therefore the existing stoichiometric theory is developed to include this route of supply. The females were essentially devoid of lipid reserves, as evidenced by the lack of the storage fatty acids 20:1(n−9) and 22:1(n−11), and carbon limitation was predicted under most of the scenarios examined. Nitrogen limitation was only apparent when carbon and nitrogen utilisation efficiencies were assumed to be high (0.5) and low (0.4) respectively. PUFAs were assumed to be utilised with high efficiency (0.9), and were never predicted to limit production. This work highlights the need for a more detailed understanding of the maintenance requirements that marine copepods have for C, N, EPA, and DHA and hence the efficiencies with these substrates can be utilised for growth. 相似文献
752.
R. D. Coombe 《运输评论》2013,33(2):165-188
Abstract The recent completion of two major transport studies of predominantly urban areas in the Middle East (Amman‐Jordan and Bahrain) has provided the opportunity to compare and contrast the transport characteristics of, and medium term transport policies for, the two areas. While in structure the two transport systems have many similarities, their base year usage differs significantly. In view of the much lower income levels in Amman, and the resulting lower levels of car ownership, greater reliance is placed on public transport in Amman than in the more car‐oriented society in Bahrain. Against this background, and in the context of broadly similar overall levels of growth in travel demand, their development in the medium term future should follow different paths. Amman will need to depend on public transport very heavily, with only limited road building. Bahrain should be able to develop a satisfactory road system, with public transport playing its current role except for the provision of services for some relatively modest number of restrained private vehicle users. In both cases, however, substantial investment in off‐street parking spaces is needed. The paper briefly describes the social and economic backgrounds of the two areas, and reviews the transport systems and the organisations responsible for them. Travel demand forecasts are summarized, leading to the transport plan and policy development. The prospects for implementation are discussed, and the paper lastly focuses on some aspects which are key to the development of the transport systems in the two countries. 相似文献
753.
Erika Spissu Abdul Rawoof Pinjari Chandra R. Bhat Ram M. Pendyala Kay W. Axhausen 《Transportation》2009,36(5):483-510
Activity-travel behavior research has hitherto focused on the modeling and understanding of daily time use and activity patterns
and resulting travel demand. In this particular paper, an analysis and modeling of weekly activity-travel behavior is presented
using a unique multi-week activity-travel behavior data set collected in and around Zurich, Switzerland. The paper focuses
on six categories of discretionary activity participation to understand the determinants of, and the inter-personal and intra-personal
variability in, weekly activity engagement at a detailed level. A panel version of the Mixed Multiple Discrete Continuous
Extreme Value model (MMDCEV) that explicitly accounts for the panel (or repeated-observations) nature of the multi-week activity-travel
behavior data set is developed and estimated on the data set. The model also controls for individual-level unobserved factors
that lead to correlations in activity engagement preferences across different activity types. To our knowledge, this is the
first formulation and application of a panel MMDCEV structure in the econometric literature. The analysis suggests the high
prevalence of intra-personal variability in discretionary activity engagement over a multi-week period along with inter-personal
variability that is typically considered in activity-travel modeling. In addition, the panel MMDCEV model helped identify
the observed socio-economic factors and unobserved individual specific factors that contribute to variability in multi-week
discretionary activity participation.
Erika Spissu is currently a Research Fellow at the University of Cagliari (Italy). She received her Ph.D. from the University of Palermo and University of Cagliari (Italy) in Transport techniques and economics. She spent the past 2 years at the University of Texas at Austin as a Research Scholar focusing primarily in activity-based travel behavior modeling, time use analysis, and travel demand forecasting. Abdul Rawoof Pinjari is an Assistant Professor in the Department of Civil and Environmental Engineering at the University of South Florida, Tampa. His research interests include time-use and travel-behavior analysis, and activity-based approaches to travel-demand forecasting. He has his Ph.D. from the University of Texas at Austin. Chandra R. Bhat is a Professor in Transportation at The University of Texas at Austin. He has contributed toward the development of advanced econometric techniques for travel behavior analysis, in recognition of which he received the 2004 Walter L. Huber Award and the 2005 James Laurie Prize from the American Society of Civil Engineers (ASCE), and the 2008 Wilbur S. Smith Distinguished Transportation Educator Award from the Institute of Transportation Engineers (ITE). He is the immediate past chair of the Transportation Research Board Committee on Transportation Demand Forecasting and the International Association for Travel Behaviour Research. Ram M. Pendyala is a Professor of Transportation Systems in the Department of Civil, Environmental, and Sustainable Engineering at Arizona State University. He teaches and conducts research in travel behavior analysis, travel demand modeling and forecasting, activity-based microsimulation approaches, and time use. He specializes in integrated land use—transport models, transport policy formulation, and public transit planning and design. He is currently the Vice-Chair of the International Association for Travel Behavior Research and is the immediate past chair of the Transportation Research Board Committee on Traveler Behavior and Values. He has his PhD from the University of California at Davis. Kay W. Axhausen is a Professor of Transport Planning at the Swiss Federal Institute of Technology (ETH) Zurich. Prior to his appointment at ETH, he worked at the Leopold Franzens University of Innsbruck, Imperial College London and the University of Oxford. He has been involved in the measurement and modelling of travel behaviour for the last 25 years, contributing especially to the literature on stated preferences, microsimulation of travel behaviour, valuation of travel time and its components, parking behaviour, activity scheduling and travel diary data collection. 相似文献
Kay W. AxhausenEmail: |
Erika Spissu is currently a Research Fellow at the University of Cagliari (Italy). She received her Ph.D. from the University of Palermo and University of Cagliari (Italy) in Transport techniques and economics. She spent the past 2 years at the University of Texas at Austin as a Research Scholar focusing primarily in activity-based travel behavior modeling, time use analysis, and travel demand forecasting. Abdul Rawoof Pinjari is an Assistant Professor in the Department of Civil and Environmental Engineering at the University of South Florida, Tampa. His research interests include time-use and travel-behavior analysis, and activity-based approaches to travel-demand forecasting. He has his Ph.D. from the University of Texas at Austin. Chandra R. Bhat is a Professor in Transportation at The University of Texas at Austin. He has contributed toward the development of advanced econometric techniques for travel behavior analysis, in recognition of which he received the 2004 Walter L. Huber Award and the 2005 James Laurie Prize from the American Society of Civil Engineers (ASCE), and the 2008 Wilbur S. Smith Distinguished Transportation Educator Award from the Institute of Transportation Engineers (ITE). He is the immediate past chair of the Transportation Research Board Committee on Transportation Demand Forecasting and the International Association for Travel Behaviour Research. Ram M. Pendyala is a Professor of Transportation Systems in the Department of Civil, Environmental, and Sustainable Engineering at Arizona State University. He teaches and conducts research in travel behavior analysis, travel demand modeling and forecasting, activity-based microsimulation approaches, and time use. He specializes in integrated land use—transport models, transport policy formulation, and public transit planning and design. He is currently the Vice-Chair of the International Association for Travel Behavior Research and is the immediate past chair of the Transportation Research Board Committee on Traveler Behavior and Values. He has his PhD from the University of California at Davis. Kay W. Axhausen is a Professor of Transport Planning at the Swiss Federal Institute of Technology (ETH) Zurich. Prior to his appointment at ETH, he worked at the Leopold Franzens University of Innsbruck, Imperial College London and the University of Oxford. He has been involved in the measurement and modelling of travel behaviour for the last 25 years, contributing especially to the literature on stated preferences, microsimulation of travel behaviour, valuation of travel time and its components, parking behaviour, activity scheduling and travel diary data collection. 相似文献
754.
755.
L.D. Poulikakos A.R. Lees K. Heutschi P. Anderegg 《Transportation Research Part D: Transport and Environment》2009,14(7):507-513
The European Union project Eureka Logchain Footprint is an ongoing project to identify road and rail vehicles by means of their environmental footprint as characterised by dynamic load, noise, ground borne vibrations and gaseous emissions induced by the vehicle. Part of the project involves the installation of road and rail footprint monitoring stations throughout Europe. This paper presents results of the road stations in Switzerland and the UK. Individual vehicle data from weigh-in-motion and noise are compared. The results indicate that a significant number of vehicles surpass the limits set in both countries. It was shown that the UK sites are generating higher noise levels than their Swiss counterparts; in part due to the much coarser aggregate embedded in the running course of the pavement employed in the UK. Such data can be used to create an incentive for vehicle types with a low footprint and a penalty for vehicles with a large footprint. 相似文献
756.
Su-Han Woo Sun-Nam Kim Stephen Pettit Anthony Beresford 《Maritime Policy and Management》2018,45(1):19-33
Global offshoring has increased the need for transport of half-finished goods and components, along with finished goods. The auto-parts industry in Korea has also entered the global market as Korean car manufacturers have started to build overseas factories. Maintaining cost competitiveness by minimising total logistics costs will thus be a critical strategy for the industry. This research compares the total annual costs of four feasible transport routes from Korea to the US using the inventory-theoretic model, which encompasses direct transport costs, in-transit carrying costs, and warehouse inventory costs. We apply this model to real transport data collected from a Korean auto-parts company. A static analysis shows that inventory costs can play a decisive role in altering the cost competitiveness of different routes. In addition, sensitivity and scenario analyses with changes in variables and the market situations reveal that the cost structure of each route plays an important role in determining their relative cost competitiveness in varying market conditions. 相似文献
757.
D. R. Jones 《运输规划与技术》2013,36(5):521-543
Abstract Aviation passenger traffic is forecast to grow significantly over the next decade and beyond. To accommodate this growth will require investment in airport infrastructure, including terminals. These buildings represent large, lumpy investments, so it is important to provide the capacity to accommodate the forecast traffic. However, this depends on at least two factors: the accuracy of the forecast of future demand, and the process of translating these forecasts into designs. Error in either factor can be potentially catastrophic financially. Translating forecasts into designs depends on ‘rules of thumb’ formulae that convert design hour flows into area requirements for each terminal facility. This paper examines the process of translating demand forecasts into conceptual terminal designs. The basic methods used are outlined, and how they affect the conceptual terminal design process are revealed. A model for conceptual terminal design is derived, presented and validated based on a sample of UK airports. It is shown that even if demand forecasts can be taken to be completely accurate, there can still be errors in terminal design and size resulting from the use of these ‘rules of thumb’. 相似文献
758.
Fishing is one of the most dangerous occupations in the world. Numerous research studies have been carried out to improve fishing safety from many different perspectives. Several of these studies focused on the relationship between environmental factors, climate change effects, and fishing safety. This paper aims to suggest a knowledge mobilization structure that translates findings of this type of research into input of evidence-based decision making and consequently improve and update fishing policies with respect to fishing safety and environmental conditions. Significant safety factors extracted from related literature are stability of vessels, fisheries management, safety equipment, communication, insurance, training, safety information and culture, weather forecasts, fatigue, and search and rescue planning. The paper then reviews policies related to these factors to examine if they address extreme environmental conditions and climate change effects. The paper presents recommendations to improve general fishing safety with respect to short- and long-term environmental considerations. 相似文献
759.
760.