全文获取类型
收费全文 | 365篇 |
免费 | 7篇 |
专业分类
公路运输 | 23篇 |
综合类 | 16篇 |
水路运输 | 140篇 |
铁路运输 | 6篇 |
综合运输 | 187篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 11篇 |
2017年 | 13篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 92篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 24篇 |
2009年 | 16篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 13篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1976年 | 1篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1972年 | 1篇 |
排序方式: 共有372条查询结果,搜索用时 15 毫秒
281.
There is a large body of literature, spanning multiple disciplines, concerned with the relationship between traditional (physical) shopping and associated travel behaviour. However, despite the recent rapid growth of digital retailing and online shopping, the impact on travel behaviour remain poorly understood. Although the issue of the substitution and complementarity between conventional and virtual retail channels has been extensively explored, few attempts have been made to extend this work so as to incorporate virtual retail channels into modelling frameworks that can link shopping and mobility decisions. Here, we review the existing literature base with a focus on most relevant dimensions for personal mobility. How online activity can be incorporated into operational transport demand models and benefits of such effort are discussed. Existing frameworks of shopping demand are flexible and can, in principle, be extended to incorporate virtual shopping and the associated additional complexities. However, there are significant challenges associated with lack of standard ontologies for crucial concepts and insufficiencies in traditional data collection methods. Also, supply-side questions facing businesses and policy-makers are changing as retailing goes through a digital transformation. Opportunities and priorities need to be defined for future research directions for an assessment of existing tools and frameworks. 相似文献
282.
The number of conventionally fuelled motor vehicles in use is increasing worldwide despite warnings about finite fossil fuel and the detrimental impacts of burning such fuels. While electric vehicles, the subject of much research, generate far less emissions and offer the potential for power from renewable sources, they are yet to significantly penetrate the market. Tangible barriers such as price and vehicle range still exist, but consumer attitudes also drive behaviour. This paper examines attributes in a framework relatively new to transportation and energy policy; best–worst scaling. This method is widely considered an improvement over traditional methods of eliciting attitudes and beliefs, where respondents select attitudes they find best or worst from a set of attitudinal statements. To avoid potential endogeneity bias, we jointly model attitudes and choice for the first time with best–worst data. It is found that energy crisis, air quality and climate change concerns influence behaviour with respect to vehicle range and that travel behaviour change and forms of government incentives are needed influences on behaviour with respect to vehicle emissions. It is argued that correctly modelling attitudes reduces the error term of the vehicle choice model and provides policy makers with an improved lens for assessing behaviour. Additionally, the methods described within can easily be adapted to other policy scenarios. 相似文献
283.
The opportunity to have seven data sets associated with a stated choice experiment that are very similar in content and design
is rare, and provides an opportunity to look in detail at the empirical evidence within and between each data set in the context
of a range of discrete choice estimation methods, from multinomial logit to latent class to scale multinomial logit to mixed
logit, and the most general model, generalized mixed multinomial logit that accounts for preference and scale heterogeneity.
Given the problems associated with data from different countries and time periods, we estimate separate models for each data
set, obtaining values of travel time savings that are then updated post estimation to a common dollar for comparative purposes.
We also pooled all data sets for a scaled MNL model, treating each data set as a set of three separate utility expressions,
but linked to the other data sets through scale heterogeneity. This is not behaviourally appropriate with MNL, latent class
or mixed logit. The main question investigated is whether there exists greater synergy in the willingness to pay evidence
within model form across data sets compared to across model forms within data sets. The evidence suggests that there is a
relatively greater convergence of evidence across the choice models, with the exception of generalized mixed logit, after
controlling for data set differences; and there is strong evidence to suggest that differences between data sets do matter. 相似文献
284.
Successful public transport service contracts can be judged against procedural and outcome criteria, located within an integrated strategic, tactical and operational level framework for planning and delivery. Clear goal setting at the strategic level sets the basis for supportive tactical system planning and for service delivery that meets goals. The workshop considers relevant success criteria and key matters that need to be resolved for their achievement. Market growth potential and the governmental attitude to supporting service growth are important issues shaping the contractual environment. The growing interest in negotiated performance-based contracts and the role of trust between the operator and the authority are also matters for particular attention. 相似文献
285.
Earl J. Baker Robert E. Deyle Timothy S. Chapin John B. Richardson 《Coastal management》2013,41(3):294-317
Five coastal counties in Florida were studied to assess the effect of state-mandated local comprehensive plan policies on hurricane evacuation clearance times and public shelter demand. Numbers of residential units in 2002 and at the time of plan approval were estimated from property parcel data. Abbreviated transportation models were used to calculate 2002 evacuation times and shelter demand and to ascertain the impacts of post-plan residential growth within hurricane hazard areas. Calculated increases in clearance times and shelter demand are not in concert with the state's mandate to maintain or reduce clearance times. State law currently limits the leverage of the state planning agency to compel local governments to implement the required comprehensive plan policies. We recommend a concurrency management strategy that parallels the state's requirement to provide adequate transportation facilities to accommodate the impacts of future residential growth. Such a policy could be employed in other states as well. 相似文献
286.
This article reports the results of the travel cost model using the standard and the truncated count data models to estimate the economic value of the Similan Islands, Thailand, from SCUBA diving. The estimated consumer surplus per visit to the Similan Islands using the truncated negative binomial model was US$3,233 and the economic value of the Similan Islands from SCUBA diving was estimated to be up to US$54.96 m. This study shows that, even without non-use values, coral reefs of the Similan Islands, if properly managed and maintained, will continue to have significant value to both Thai and overseas SCUBA divers, as one of the natural treasures of the world. 相似文献
287.
This article, one part of the National Coastal Zone Management Effectiveness Study, evaluates the effectiveness of state coastal management programs in protecting estuaries and coastal wetlands. State programs were evaluated in a four-step, indicatorbased process to estimate (1) the relative importance of the issue; (2) the potential effectiveness of programs based on the policies, processes, and tools used; (3) outcome effectiveness based on on-the-ground indicators; and (4) overall performance, where outcome effectiveness was compared to issue importance and potential effectiveness. State evaluations were synthesized to provide a national perspective on CZM contributions and effectiveness in estuary and wetland protection. Although on-the-ground outcome data were sparse, they were sufficient to determine at least probable levels of effectiveness for about one-third of the states. Of these states, 80% were performing at expected or higher levels, considering how important the issue was in their state, and the scope and strength of the policies, processes, and tools they had deployed. Monitoring and record keeping, freshwater wetland management, and the use of nonregulatory restoration in coastal management were common program weaknesses. The evaluation approach and indicators used here are recommended as a starting point for designing a national monitoring and performance evaluation system addressing this CZM objective. 相似文献
288.
Abstract This article reviews the conflicts that led to the establishment of a special Congressional Committee on offshore oil and gas exploration, development, and production and the attempted resolution of various issues by that Committee and the Congress in the 1978 Amendments to the Outer Continental Shelf Lands Act of 1953. A short review is provided of the history of Outer Continental Shelf (OCS) development, of the conflict between the federal government and other interested entities and persons, and of the Congressional mechanism to respond to these conflicts. A more detailed analysis is provided of the most significant OCS issues. The article describes the various risks and benefits of offshore activity and the various benefits and risks of proposed changes in the law concerning such development. A review of the Congressional mechanism to assess these risks and benefits and balance them is included in a discussion of the various issues and legislated solutions. Finally, the article notes the need for continuing oversight and review of the benefits and risks and how effective the 1978 Amendments are in balancing them. 相似文献
289.
Abstract This introductory piece traces the growth of knowledge and activity associated with visual resource management in general. A specific framework of questions regarding methods of coastal zone visual resource management is presented. The state‐of‐the‐art in methodological studies is listed for each question, and the methodological questions are related to the major articles with the special issue of the Coastal Zone Management Journal. Major legal federal statutes, state statutes, and court cases are reviewed in light of visual resource management in the coastal zone. The remaining articles within the special issue that deal with integration of VRM into decision‐making are then arrayed against a management framework. This framework includes regulatory situations for (1) public land management and planning, (2) public projects involving private lands, and (3) public regulation of private projects. 相似文献
290.