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   529篇
  免费   24篇
公路运输   114篇
综合类   191篇
水路运输   93篇
铁路运输   60篇
综合运输   95篇
  2024年   3篇
  2023年   3篇
  2022年   11篇
  2021年   18篇
  2020年   27篇
  2019年   8篇
  2018年   16篇
  2017年   16篇
  2016年   25篇
  2015年   18篇
  2014年   49篇
  2013年   56篇
  2012年   42篇
  2011年   48篇
  2010年   30篇
  2009年   26篇
  2008年   28篇
  2007年   36篇
  2006年   29篇
  2005年   26篇
  2004年   9篇
  2003年   3篇
  2002年   7篇
  2001年   1篇
  2000年   4篇
  1999年   3篇
  1998年   1篇
  1996年   3篇
  1995年   1篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
排序方式: 共有553条查询结果,搜索用时 15 毫秒
171.
Individual aspirations of associating with role models are routinely harnessed by marketers, who for instance, use celebrity endorsement in selling brands and products. It appears there has been no research to date, however, on the potential for celebrity activism, or role model advocacy beyond celebrities, such as from politicians, to form effective interventions for encouraging sustainable transport behavior. This is despite studies suggesting that celebrity endorsement is a potential gateway for transforming public opinion on carbon intensive transport modes. The present paper consequently offers a critical review of the literature on role model advocacy and celebrity activism, and how these concepts have been harnessed to address environmental issues, in order to conceptually assess the potential for extending these intervention techniques to the context of sustainable transport. The scope of the paper includes the potential that high profile politicians/celebrities might play as role models in exercising referent power to influence social norms surrounding sustainable transport, given that the success of social marketing interventions are closely tied to the need for changes in the policy landscape. Key dimensions of role model endorsement in transport are identified and applied to a series of examples of how celebrity and political role models have influenced transport cultures. In addition to offering an original application of a theoretical framework to a new context, in order to help address the increasingly important societal issue of transport’s growing contribution to climate change, the paper discusses the challenges associated with the neoliberal framing of this approach.  相似文献   
172.
Urban populations transport risk perception is interesting because it is associated with travel mode choices and use. This study investigates changes in transport-related risk constructs in the urban population in Norway in 2004 and 2013, and describes whether people perceive private or public to be associated with the highest risk. The results are based on self-completion questionnaire surveys conducted in two independent representative samples living in the same urban areas in 2004 (n?=?592) and 2013 (n?=?1035). Overall, the respondents perceived the risk as lower in 2013 than in 2004. For both time periods, people consistently assessed the risk constructs related to private motorized transportation as higher than corresponding risk in public transportation. The findings suggest that while transportation risk perception in urban populations may change over time, the pattern that private motorized transportation is associated with a higher perceived risk than public transportation remains stable.  相似文献   
173.
高速列车通过隧道时压力变化的数值模拟   总被引:3,自引:0,他引:3  
采用三维粘性、不等熵、可压缩、非定常流的Navier Stokes方程,用有限体积法进行区域离散,对高速列车通过隧道时所引起的压力变化进行模拟。在模拟中同时考虑了列车速度、阻塞比、列车形状对隧道内压力的历时变化的影响,并将模拟结果与木川田一弥、森井宣的水槽实验结果和英国patchway隧道现场量测结果进行了比较,三者基本相吻合。实验及计算结果表明,隧道内产生的最大压力和列车速度、阻塞比等相关。  相似文献   
174.
叙述了钢渣的物理力学性质,并针对其膨胀特性提出了如何因势利导,扬长避短用于道路修建的几种方法。  相似文献   
175.
既有多梁式桥梁的损伤识别   总被引:3,自引:2,他引:1  
讨论了利用量测的柔度矩阵定位损伤的方法。分别选用模态柔度和模态柔度曲率两种方法对多梁式T型梁桥的损伤识别进行研究;并定性分析了测试噪声对损伤识别结果的影响。为反映实际多梁式桥梁的损伤识别情况,采用符合实际多梁式桥梁结构构形的计算模型模拟结构损伤。通过一个简支多梁式T梁桥的数值试验验证了所提方法的可行性。结果表明在量测模态与频率数不多的情况下,所讨论的方法可用于识别多梁式桥梁的损伤。  相似文献   
176.
Scenarios of low-carbon transport demonstrate that a vast range of different outcomes is possible and contingent on policy, technology and cultural developments. But a closer look indicates that different schools of thought suggest possible pathways diverging in their fine structure. This perspective reveals how three different scientific communities — integrated assessment modelers, transport-sector modelers, and place-based modelers — emphasize distinct solution domains. While integrated assessment models focus on fuel composition, transport-sector models put slightly higher emphasis on efficiency measures; in turn place-based research specifies idiosyncratic behavioral and infrastructural mitigation options that are likely to be beneficial in realizing local co-benefits. These specific local approaches could mitigate urban transport emissions by 20–50%, higher than that revealed in aggregate global models. We discuss differences in approach, possibilities for reconciliation, and the implications of normative assumptions. Targeted three-directional interactions would foster comprehensive understanding of possible low-carbon transportation futures.  相似文献   
177.
精心设计、加强设计后续服务、强化变更设计管理、各方密切配合、严格控制设计变更,是控制山区高速公路工程造价的有效途径,可供同类工程参考。  相似文献   
178.
本文利用初等变换给出了一种已知矩阵的特征值、特征向量求此矩阵的一种新方法。  相似文献   
179.
对按合同约定管理公路工程变更进行了几点说明.  相似文献   
180.
长江南支白茆沙河段自1965年开辟海轮航道,航道经常调标改道。分析表明航槽不稳定与河势、滩槽不稳定有关,没有稳定的河势就没有稳定的航槽。汊道兴衰使航槽改道,而深槽变化使航道经常调标,航道变迁也与上游通州沙河段河势不稳定及北支水沙到灌影响有关。随着上游河势趋于相对稳定,徐六泾主流稳定南偏,长江主流走南水道的格局趋于相对稳定,海轮航道稳定在白茆沙南水道。从河势变化趋势、航道水深条件等考虑选择白茆沙南水道为深水航道通航汊道。  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