全文获取类型
收费全文 | 108篇 |
免费 | 8篇 |
专业分类
公路运输 | 26篇 |
综合类 | 41篇 |
水路运输 | 20篇 |
铁路运输 | 13篇 |
综合运输 | 16篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1995年 | 2篇 |
1989年 | 1篇 |
排序方式: 共有116条查询结果,搜索用时 296 毫秒
1.
为探究新冠肺炎疫情下交通防控政策对长沙市人口流动的影响,本文根据长沙市在新冠
肺炎疫情期间颁布的交通防控政策和疫情实时防控情况划分防控阶段,基于百度迁徙大数据,利
用双重差分模型,识别长沙市不同阶段的交通防控政策以及量化防控效果,分析交通防控政策对
长沙市人口流动的影响。结果显示,长沙市在交通管制阶段,平均人口迁出强度、平均人口迁入
强度及城市内部出行强度分别下降了83.68%、69.24%及59.74%,有效地控制了人口流动,降低了
疫情扩散危险。在交通恢复阶段,长沙市人口流动强度逐渐反弹,城市内部出行强度基本恢复到
2019年同期水平。本文研究结果显示了交通管制对疫情扩散限制的有效性,为常态化疫情防控
下精准防控政策和复工复产政策制定提供参考。 相似文献
2.
Aircraft noise has been regarded as one of the major environmental issues related to air transport. Many airports have introduced a variety of measures to reduce its impact. Several air traffic assignment strategies have been proposed in order to allocate noise more wisely. Even though each decision regarding the assignment of aircraft to routes should consider population exposure to noise, none of the air traffic assignment strategies has addressed daily migrations of population and number of people exposed to noise. The aim of this research is to develop a mathematical model and a heuristic algorithm that could assign aircraft to departure and arrival routes so that number of people exposed to noise is as low as possible, taking into account temporal and spatial variations in population in an airport’s vicinity. The approach was demonstrated on Belgrade airport to show the benefits of the proposed model. Numerical example showed that population exposure to noise could be reduced significantly by applying the proposed air traffic assignment model. As a consequence of the proposed air traffic assignment, overall fuel consumption increased by less than 1%. 相似文献
3.
Noise pollution in urban areas has many harmful effects on the citizens. There are varieties of noise generation sources of which the traffic noise could be a major source. The point which is perhaps less noticed is that sound level is not the only parameter to indicate the extent and intensity of noise pollution. Situation of urban land uses, distribution of population centers and types of passages can deeply affect the concern on this environmental issue but not with a similar ratio. This article presents an overlaying technique to define noise prone areas using all different factors involved. A case study was carried out in the District 14 of Tehran Metropolitan City where there are busy streets and highways. For this purpose, the share of each criterion in noise pollution intensity was determined using Analytical Hierarchy Process (AHP). Afterwards, the map layers were overlaid based upon the relative importance of the criteria to get the final map on which the noise prone areas are specified. The developed method could be used as a tool for indirect estimation of noise pollution by which instead of direct measurement of the equivalent sound level, it would be possible to predict noise susceptible areas considering the most important influential factors. 相似文献
4.
Toshiyuki Yamamoto 《Transportation》2009,36(3):351-366
The interactions among different types of vehicle ownership including car, motorcycle and bicycle are examined by developing
simultaneous vehicle ownership models in this study. Large scale person trip survey data for Osaka metropolitan area, Japan
and Kuala Lumpur, Malaysia are used for empirical analysis. The results suggest that population density at residential area
significantly and negatively affects car ownership for both areas, and that the effects are larger for Osaka metropolitan
area than for Kuala Lumpur. Also, bicycle ownership becomes higher at higher population density area for Osaka area, while
higher at lower population density area for Kuala Lumpur, which represents the different usage patterns of bicycle between
the two areas.
相似文献
Toshiyuki YamamotoEmail: |
5.
Asha Weinstein Agrawal Paul Schimek 《Transportation Research Part D: Transport and Environment》2007,12(8):548-563
This paper examines data about walking trips in the US Department of Transportation’s 2001 National Household Travel Survey. The paper describes and critiques the methods used in the survey to collect data on walking. Using these data, we summarize the extent of walking, the duration and distance of walk trips, and variations in walking behavior according to geographic and socio-demographic factors. The results show that most Americans do not walk at all, but those who do average close to thirty minutes of walking a day. Walk trips averaged about a half-mile, but the median trip distance was a quarter of a mile. A significant percentage of the time Americans’ walk was spent traveling to and from transit trips. Binary logit models are used for examining utility and recreational walk trips and show a positive relationship between walking and population density for both. For recreational trips, this effect shows up at the extreme low and high ends of density. For utility trips, the odds of reporting a walk trip increase with each density category, but the effect is most pronounced at the highest density categories. At the highest densities, a large portion of the effect of density occurs via the intermediary of car ownership. Educational attainment has a strong effect on propensity to take walk trips, for both for utility and recreation. Higher income was associated with fewer utility walk trips but more recreational trips. Asians, Latinos, and blacks were less likely to take utility walk trips than whites, after controlling for income, education, density, and car ownership. The ethnic differences in walking are even larger for recreational trips. 相似文献
6.
7.
乘用车市场的发展态势是各大汽车制造企业关注的焦点,对企业制定发展战略和及时调整产业结构至关重要。在分析2013年乘用车市场逐步走高态势形成原因的基础上,对比美、欧、日等国家的汽车销量和保有水平,对2014年我国乘用车市场需求及发展走势进行了预测。受发展规律、宏观经济及汽车政策的影响,2014年我国乘用车需求预计为1860万辆,同比增长14%。2014年乘用车市场将继续保持平稳快速发展。 相似文献
8.
9.
选择移居2500m高原63名矽肺矿工,连续20年摄后前位胸片,按居住年限分组,自身对照,观察矽肺与肺动脉高压的演变过程.分析矽肺X线心血管4项指标的改变。结果表明:动态观察矽肺X线及心血管各指标的改变,对预测高原人体矽肺的发生,评定矽肺的发展程度,观察疗效和对矽肺愈后判定有着非常重要的临床应用价值。 相似文献
10.
春运摩托车返乡潮是我国近几年出现的独特新现象,其交通事故频发的状况引起了社会的高度关注。针对此问题,采用交通系统工程的分析方法,构建了摩托车交通安全系统的基本要素及其相互关系模型图,以有关的文献报道和调查资料为基础,从人、车、路、环境和管理等方面归纳分析了恶劣天气型、疲劳行车型、黑夜行车型、路况不熟型、路况不良型及骑车技能不佳型等6种类型摩托车交通事故的机理。最后分别给公路管理部门、交警部门及政府提出了对策建议。 相似文献