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   54篇
  免费   0篇
公路运输   5篇
综合类   3篇
水路运输   18篇
综合运输   28篇
  2021年   2篇
  2020年   3篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   2篇
  2013年   13篇
  2012年   2篇
  2011年   2篇
  2010年   1篇
  2009年   4篇
  2008年   1篇
  2007年   1篇
  2005年   1篇
  2004年   1篇
  1995年   3篇
  1994年   4篇
  1985年   1篇
  1983年   1篇
  1981年   1篇
  1977年   2篇
  1975年   1篇
排序方式: 共有54条查询结果,搜索用时 15 毫秒
1.
著名的莆田祥应庙前身是当地白杜方氏家族专用的祠堂.庙里供奉的神灵显惠侯,当地的百姓把他视为农业生产及生命财产的保护神,同时,他也是航海者信奉的神灵.本文作者以周尾和朱纺这两人出海之前均到该庙膜拜的典型事例,分析指出上述二人的出海经商与白杜方氏家族存在着直接关系,可能是受雇于当时既从事农业又涉猎海上贸易的白杜方氏家族,因此宋时显惠侯只是一个地方性的神灵,只对某一部分人提供某些特定的庇护,并不具有普遍意义.  相似文献   
2.
The work described was undertaken as part of the CASSIOPE project in the EC DRIVE programme. A range of fare collection procedures in public transport is described, and the importance of these for data collection by operators is stressed. It is suggested that such data management could be standardized and to this end four case studies were carried out in different European cities. Data models were built for each city, and these models are merged into a preliminary version of a generalized model. The need and uses for such a fare collection data model is explained.  相似文献   
3.
Carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NO) emission factors (EFs) are measured with a commercial vehicle emissions remote sensing system (VERSS) during a large-scale vehicle exhaust emissions study in Las Vegas. Particulate matter (PM) EFs are simultaneously measured for individual vehicles with a newly developed PM-VERSS based on ultraviolet backscatter light detection and ranging (Lidar). The effectiveness of CO and HC EFs as proxy for NO and PM EFs for spark-ignition vehicles is evaluated. Poor correlations were found between EFs for pollutants on an individual vehicle basis indicating that high EFs for one or more pollutants cannot be used as a predictor of high EFs for other pollutants. Stronger functional relationships became evident after averaging the EF data in bins based on rank-order of a single pollutant EF. Low overlap between the highest 10% emitters for CO, HC, NO, and PM was found. These results imply that for an effective reduction of the four pollutants, inspection and maintenance (I/M) programs, including clean screening, should measure all four pollutants individually. Fleet average CO and HC concentrations determined by gaseous VERSS were compared with fleet average CO and HC concentrations measured at low-idle and at high-idle during local I/M tests for spark-ignition vehicles. The fleet average CO concentrations measured by I/M tests at either idle were about half of those measured by remote sensing. The fleet average high-idle HC concentration measured by I/M tests was about half of that measured by VERSS while low-idle I/M and VERSS HC average concentrations were in better agreement. For a typical vehicle trip, most of the fuel is burned during non-idle conditions. I/M measurements collected during idling conditions may not be a good indicator of a vehicle’s potential to be a high emitter. VERSS measurements, when the vehicle is under a load, should more effectively identify high emitting vehicles that have a large contribution to the mobile emissions inventory.  相似文献   
4.
This study estimates a random parameter (mixed) logit model for active transportation (walk and bicycle) choices for work trips in the New York City (using 2010–2011 Regional Household Travel Survey Data). We explored the effects of traffic safety, walk–bike network facilities, and land use attributes on walk and bicycle mode choice decision in the New York City for home-to-work commute. Applying the flexible econometric structure of random parameter models, we capture the heterogeneity in the decision making process and simulate scenarios considering improvement in walk–bike infrastructure such as sidewalk width and length of bike lane. Our results indicate that increasing sidewalk width, total length of bike lane, and proportion of protected bike lane will increase the likelihood of more people taking active transportation mode This suggests that the local authorities and planning agencies to invest more on building and maintaining the infrastructure for pedestrians. Further, improvement in traffic safety by reducing traffic crashes involving pedestrians and bicyclists, will increase the likelihood of taking active transportation modes. Our results also show positive correlation between number of non-motorized trips by the other family members and the likelihood to choose active transportation mode. The model would be an essential tool to estimate the impact of improving traffic safety and walk–bike infrastructure which will assist in investment decision making.  相似文献   
5.
ABSTRACT

Predicting the risk of traffic demands and delays exceeding critical limits at road junctions, airports, hospitals, etc., requires knowing how both mean and variance of queue size vary over time. Microscopic simulation can explore variability but is computationally demanding and gives only sample results. A computationally efficient approximation to the mean is used in many modelling tools, but only empirical extensions for variance in particular situations have been available. The paper derives theoretical formulae for time-dependent and equilibrium variance, believed to be novel and to apply generally to queues covered by the Pollaczek–Khinchin mean formula, and offering possible structural insights. These are applied in an extended approximation giving mutually consistent mean and variance estimates with improved accuracy. Tests on oversaturated peak demand cases are compared with Markov probabilistic simulation, demonstrating accuracy (R2?>?0.99) for typical random, priority-like (M/M/1) and traffic-signal-like (M/D/1) queues. Implications for risk analysis, planning and policy are considered.  相似文献   
6.
Abstract

Analysis of recent substantive coastal land use management laws shows that their main thrust is to provide for protection of the coastal environment from adverse impacts of uncontrolled development. The four purposes cited most frequently among laws of 17 states were: Protection of wildlife and fisheries, protection of ecosystems or the natural environment, control of development, and enhancement of esthetic values. Other purposes were to: Protect life and property, enhance public recreation, conserve soil, and protect water resources. Development and economic purposes were cited in relatively few laws.  相似文献   
7.
8.

This paper reviews the provision of public transport in the Cape Town Metropolitan Area and the proposals for its future development. A vitally distinguishing characteristic of public transport in Cape Town and other South African cities is the fractured market with great discrepancies between different segments. These range from those with high incomes and preferences similar to those found in typically First World countries to a great majority living at or below minimum poverty levels with virtually no choices and a very different set of needs and preferences. Although scope for improving service levels and satisfying user needs is unlimited, in South Africa resources for transport are facing severe competition from other macrolevel social and economic imperatives, such as combating crime and addressing discrepancies in health and education needs. This situation represents a huge challenge to those responsible for planning and developing public transport strategies. Evidence is presented that current public transport services are unsustainable in terms of increasing subsidy requirements while also not effectively meeting user needs. Proposals to restructure the public transport system and to use Stated Preference techniques to identify user needs are put forward. Given the fractured market for public transport in metropolitan Cape Town, Stated Preference techniques will require innovative adaptations and different approaches to those most commonly applied elsewhere in the world and this paper provides some broad guidelines.  相似文献   
9.
10.
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