首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4667篇
  免费   316篇
公路运输   832篇
综合类   2001篇
水路运输   714篇
铁路运输   730篇
综合运输   706篇
  2024年   15篇
  2023年   25篇
  2022年   70篇
  2021年   145篇
  2020年   143篇
  2019年   96篇
  2018年   133篇
  2017年   146篇
  2016年   178篇
  2015年   212篇
  2014年   344篇
  2013年   434篇
  2012年   345篇
  2011年   415篇
  2010年   356篇
  2009年   312篇
  2008年   338篇
  2007年   316篇
  2006年   297篇
  2005年   204篇
  2004年   143篇
  2003年   89篇
  2002年   54篇
  2001年   57篇
  2000年   28篇
  1999年   16篇
  1998年   9篇
  1997年   9篇
  1996年   9篇
  1995年   9篇
  1994年   5篇
  1993年   8篇
  1992年   5篇
  1991年   5篇
  1990年   4篇
  1989年   5篇
  1988年   3篇
  1986年   1篇
排序方式: 共有4983条查询结果,搜索用时 140 毫秒
81.
The High Line is an elevated public park in New York City, transformed from an unused freight rail line. Pedestrians walking through Manhattan’s West Side can walk either on the High Line or on a footpath below. Using Manhattan as a laboratory, this paper offers a combined assessment of noise and particulate matter pollution for its pedestrians. Noise and PM2.5 levels were recorded simultaneously for two cases (i) pedestrians walking on a footpath alongside road traffic and (ii) pedestrians walking on the elevated High Line. Testing took places over three days in autumn 2014. Results were analysed to investigate if pedestrians using the High Line would have a lower pollution exposure to those using the footpath below. Results showed statistically significant differences between the upper and lower levels in exposure to both pollution types. In order to quantify the overall impact, results are expressed through a combined air–noise pollution index. This index indicates that the average reduction in PM2.5 and noise pollution along the High Line compared to the footpath below is approximately 37%.  相似文献   
82.
为划分公路城际出行链模式并分析其形成机制,本文考虑城市内部换乘过程,解析了公路旅客城际出行过程.利用昆明市1 757份公路旅客出行调查问卷数据,提取了公路城际出行链结构特征.通过测算出行链结构值,提出了公路城际出行链模式的划分方法,将公路客运城际出行链模式划分为Ⅰ、Ⅱ、Ⅲ类并分别获取了其形成机制.结果表明:昆明市公路城际通道的平均运距为237.95 km,公共交通是公路城际出行过程中城市内部换乘的主要交通方式;昆明市公路城际出行链的3类模式占比为13.9∶6.4∶4.7,整体结构较合理;其中,Ⅱ类出行链模式最能体现均衡、稳定的形成机制.对公路城际出行链的形成机制分析发现,收入因素是促使出行链结构合理化的重要动力;造成出行链结构不合理的重要因素是市内出行延误,而非城际通道出行过程.  相似文献   
83.
对国内外主城与新城衔接的新城区(郊区)轨道线特征及交通功能等因素进行总结分析,并结合武汉市及国内外典型城市新城区轨道交通规划建设经验,对新城区轨道交通线路规划关键问题做深入研究。提出对新城区轨道交通线路规划中与其他不同层次轨道线网功能及技术标准的衔接关系;与新城区发展应注重以轨道交通引领新城区协同发展,与城市空间结构高度契合关系;新城区轨道线路走向应沿预测主要客流走廊,串联新城区商业、交通枢纽等大型客流集散点,以缓解开通初期普遍面临客流量增长缓慢,客运强度偏低的问题。  相似文献   
84.
This paper uses observations from before and during the Stockkholm congestion charging trial in order to validate and improve a transportation model for Stockholm. The model overestimates the impact of the charges on traffic volumes while at the same time it substantially underestimates the impact on travel times. These forecast errors lead to considerable underestimation of economic benefits which are dominated by travel time savings. The source of error lies in the static assignment that is used in the model. Making the volume-delay functions (VDFs) steeper only marginally improves the quality of forecast but strongly impacts the result of benefit calculations. We therefore conclude that the dynamic assignment is crucial for an informed decision on introducing measures aimed at relieving congestion. However, in the absence of such a calibrated dynamic model for a city, we recommend that at least a sensitivity analysis with respect to the slope of VDFs is performed.  相似文献   
85.
Smart card data are increasingly used for transit network planning, passengers’ behaviour analysis and network demand forecasting. Public transport origin–destination (O–D) estimation is a significant product of processing smart card data. In recent years, various O–D estimation methods using the trip-chaining approach have attracted much attention from both researchers and practitioners. However, the validity of these estimation methods has not been extensively investigated. This is mainly because these datasets usually lack data about passengers’ alighting, as passengers are often required to tap their smart cards only when boarding a public transport service. Thus, this paper has two main objectives. First, the paper reports on the implementation and validation of the existing O–D estimation method using the unique smart card dataset of the South-East Queensland public transport network which includes data on both boarding stops and alighting stops. Second, the paper improves the O–D estimation algorithm and empirically examines these improvements, relying on this unique dataset. The evaluation of the last destination assumption of the trip-chaining method shows a significant negative impact on the matching results of the differences between actual boarding/alighting times and the public transport schedules. The proposed changes to the algorithm improve the average distance between the actual and estimated alighting stops, as this distance is reduced from 806 m using the original algorithm to 530 m after applying the suggested improvements.  相似文献   
86.
It is generally presupposed that the infrastructure and availability of services of general interest (like schools, medical care, social services and also public transport) impact on present demographic development in rural areas, namely depopulation and aging. Such services affect the quality of life of local people and sometimes they perform a vital necessity. It is possible to say that the absence of the mentioned services should be compensated by an effective system of public transport. In other case, especially those people who are not able to use individual cars due to the age, health, legal conditions or financial situation are bequeathed on an assistance of the family or neighbors or they stay cut off and excluded. This paper is aimed at the verification of the presupposition in the case of the South-Moravian Region – NUTS 3 region occupying the south-eastern part of the Czech Republic, bordering with Austria and Slovakia. The research method lies in analysis of the frequency, travel time and fare of public transport system and its comparison with demographic development in rural areas, especially in the peripheral ones. The results are discussed in view of the system of central places in the region and present urbanization processes like suburbanization, counterurbanization and reurbanization.  相似文献   
87.
Appropriate microeconomic foundations of mobility are decisive for successful policy design in transportation and, in particular, for the challenge of climate change mitigation. Recent research suggests that behavior in transportation cannot be adequately represented by the standard approach of revealed preferences. Moreover, mobility choices are influenced by factors widely regarded as normatively irrelevant. Here we draw on insights from behavioral economics, psychology and welfare theory to examine how transport users make mobility decisions and when it is desirable to modify them through policy interventions. First, we explore systematically which preferences, heuristics and decision processes are relevant for mobility-specific behavior, such as mode choice. We highlight the influence of infrastructure on the formation of travel preferences. Second, we argue that the behavioral account of decision-making requires policy-makers to take a position on whether transport policies should be justified by appealing to preference satisfaction or to raising subjective well-being. This distinction matters because of the (i) influence of infrastructure on preference formation, (ii) health benefits from non-motorized mobility, (iii) negative impact of commuting on happiness and (iv) status-seeking behavior of individuals. The orthodox approach of only internalizing externalities is insufficient because it does not allow for the evaluation of these effects. Instead, our analysis suggests that transport demand modeling should consider behavioral effects explicitly.  相似文献   
88.
Biodiesel use in local public transport could be especially significant in improving air quality in cities. The purpose of the experiments described in this paper was to evaluate the various (10, 20 and 50%) blends of biodiesel with diesel in the context of the engine and pollution aspects. As regards the experimental use of these findings on municipal buses, these experiments were the first reference in Hungary. The ages (15–20 years) and types of buses (Ikarus-280, Ikarus-260) used in the experiments are still common vehicles in Hungarian public transport. During our measurements, there was a significant difference between the change in fuel consumption of articulated and solo buses in traffic when compared to test bench measurements. The proportion of the engine performance reduction is nearly the same as that for biodiesel share in the blends. Most pollutants were decreasing (both at idle and full rpm), but this reduction is not directly proportional to the increase of the blending percentage. However, as for CO2, emission increase was observed in the case of idle rpm in comparison to normal diesel operation, even though this phenomenon was not due to biodiesel use, but the catalytic converter and the fact that biodiesel was used for the first time in the engine concerned.  相似文献   
89.
回顾改革开放以来中国城市综合交通体系规划在规划定位、规划目标、内容体例、技术方法、规划实施等方面的实践和探索。总结规划编制工作的基本特点:以问题为导向、融合城市总体规划、提倡以人为本理念、广泛应用定量技术方法。指出规划编制和实施过程中存在的不足:规划地位和作用认识不清、价值理念与实际行动脱节、规划实施评估环节缺失、规划管理体制机制缺乏、相关法规技术标准陈旧。结合城市交通发展新趋势,展望未来城市综合交通体系规划的重点方向:强化多规融合、强调以人为核心的规划、加强规划评估和滚动编制、加强技术创新与行业规范、深化政策保障机制研究。  相似文献   
90.
A number of approaches have been developed to evaluate the impact of land development on transportation infrastructure. While traditional approaches are either limited to static modeling of traffic performance or lack a strong travel behavior foundation, today’s advanced computational technology makes it feasible to model an individual traveler’s response to land development. This study integrates dynamic traffic assignment (DTA) with a positive agent-based microsimulation travel behavior model for cumulative land development impact studies. The integrated model not only enhances the behavioral implementation of DTA, but also captures traffic dynamics. It provides an advanced yet practical approach to understanding the impact of a single or series of land development projects on an individual driver’s behavior, as well as the aggregated impacts on the demand pattern and time-dependent traffic conditions. A simulation-based optimization (SBO) approach is proposed for the calibration of the modeling system. The SBO calibration approach enhances the transferability of this integrated model to other study areas. Using a case study that focuses on the cumulative land development impact along a congested corridor in Maryland, various regional and local travel behavior changes are discussed to show the capability of this tool for behavior side estimations and the corresponding traffic impacts.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号