全文获取类型
收费全文 | 212篇 |
免费 | 2篇 |
专业分类
公路运输 | 15篇 |
综合类 | 32篇 |
水路运输 | 88篇 |
铁路运输 | 4篇 |
综合运输 | 75篇 |
出版年
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 8篇 |
2017年 | 1篇 |
2016年 | 20篇 |
2015年 | 15篇 |
2014年 | 2篇 |
2013年 | 11篇 |
2012年 | 21篇 |
2011年 | 14篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 31篇 |
2004年 | 26篇 |
2003年 | 9篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
排序方式: 共有214条查询结果,搜索用时 15 毫秒
31.
Linking land use and transportation in a rapidly urbanizing context: A study in Delhi,India 总被引:1,自引:0,他引:1
Cities in developing countries like India are facing some of the same concerns that North American cities are: congestion and urban growth. However, there is a sense of urgency in cities like Delhi, India in that this growth is far more rapid as both urbanization and motorization are ongoing processes that have not yet peaked. In this paper, we examine land use change and its relationship with transportation infrastructure and other planning related variables in a spatial context. We estimate land use change models at two different scales from separate data. Cellular automation and Markov models were used to understand change at the regional scale and discrete choice models to predict change at the local level. The results suggest that land use in the Delhi metropolitan area is rapidly intensifying while losing variety. These changes are affected by industrial, commercial and infrastructure location and planners and policy-makers need to better understand the implications of location decisions. We also examine these results in the context of a policy framework for data-based planning that links land use and transportation models for Delhi. 相似文献
32.
Romero Fernando Gomez Juan Rangel Thais Jurado-Piña Rafael Vassallo José Manuel 《Transportation》2020,47(4):1665-1687
Transportation - In the field of road transport, Advanced Traveller Information Systems represent a relevant tool to manage road traffic, improve drivers’ utility and make a more efficient... 相似文献
33.
One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promising approach. Image reconstruction in multi-slice CT becomes, therefore, the major challenge. Known algorithms need to derive the complementary data or work only for certain range of pitches. A reconstruction algorithm was presented that works with the direct data as well as arbitrary pitches. Filter interpolation based on the proposed method was implemented easy. The results of computer simulations under kinds of conditions for four-slice CT were presented. The proposed method can obtain higher efficiency than the conventional method. 相似文献
34.
Reputation mechanism has been recently introduced into wireless sensor networks (WSNs) to overcome the deficiencies incurred
by cryptography alone. Unlike most current reputation mechanisms that are based on binomial distribution and to some extent,
do not give due attention to the aspect of energy constraint of WSNs, this research deduces and proves the feasibility that
negative binomial distribution can well be used in the reputation update with distinctive energy-saving features. Comparison
tests with respect to the energy consumption in terms of reputation computing frequencies are done between the traditional
reputation method and the one in this study. Results show that our method can save more energy for the reputation update and
thus can better meet the power constraints of WSNs. 相似文献
35.
In this study, the temperature and gas velocity distributions in hot filament chemical vapor deposition(HFCVD) diamond film growth on the end surfaces of seals are simulated by the finite volume method. The influence of filament diameter, filament separation and rotational speed of the substrates is considered. Firstly,the simulation model is established by simplifying operating conditions to simulate the temperature and gas velocity distributions. Thereafter, the deposition parameters are optimized as 0.6 mm filament diameter, 18 mm filament separation and 5 r/min rotational speed to get the uniform temperature distribution. Under the influence of the rotational speed, the difference between temperature gradients along the directions perpendicular to the filament and parallel to the filament becomes narrow, it is consistent with the actual condition, and the maximum temperature difference on the substrates decreases to 7.4?C. Furthermore, the effect of the rotational speed on the gas velocity distribution is studied. Finally, diamond films are deposited on the end surfaces of Si C seals with the optimized deposition parameters. The characterizations by scanning electron microscopy(SEM) and Raman spectroscopy exhibit a layer of homogeneous diamond films with fine-faceted crystals and uniform thickness. The results validate the simulation model. 相似文献
36.
按照6 种不同分跨的设计方案, 每种方案又按照施工阶段采取几种不同预压荷载的计算比较来研究按照预压合龙施工工艺完成体系转换的预应力连续加劲梁吊拉组合体系桥的主梁结构性能, 并选择体系的最优分跨比. 相似文献
37.
38.
多属性评价问题中不确定性、不精确性和非独立性导致的非可加性以及可鉴别性是评价中的难点问题.本文基于模糊测度和模糊积分提出一种广义的多属性聚合算子,给出了形式化表达、性质分析和多维描述.该算子能够聚合得到解决上述问题的综合评价结果,对于建立切合实际的定量化评估方法具有较好的现实意义. 相似文献
39.
从运营轨道线网客流中找寻规律,可以有效指导城市科学合理地预测轨道交通客流。本文根据目前苏州市AFC系统运营数据积累,从网络、线路、车站三个层面探讨苏州市轨道交通客流特征,分析目前线网客流特征,为后续预测模型的参数选择提供参考和依据,并且针对轨道交通规划设计及运营提出相关工作建议。 相似文献
40.