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461.
Transportation - In this paper, an optimisation model for recovery planning of road networks is presented in which both social and economic resilience is aimed to be achieved. The model is... 相似文献
462.
463.
WERNER G. HENNECKE CATHARINA A. GREVE PETER J. COWELL BRUCE G. THOM 《Coastal management》2013,41(4):449-470
Rising sea level potentially poses a threat to many coastal areas, thereby possibly affecting coastal environments, including human assets. Taking into account the precau--tionary principle demanded at the Framework Convention for Climate Change in Rio de Janeiro in 1992, coastal managers and planners are required to evaluate the possibility of both physical and economic impacts of sea-level rise. However, long-term and cost-intensive data capture is often not affordable for a first estimation of general trends. To determine physical and economic impacts on a spatial scale of less than 10 km, a rapid and low-cost method is required. A Geographic Information System (GIS), in combination with readily available data and two coastal behaviour models (the Bruun-GIS Model and the Aggradation Model) was applied to simulate shoreline recession caused by a rise in sea level. In addition, the potential impacts of a 50-year design storm were considered in conjunction with sea-level rise. The monetary vulnerability was assessed and combined with the simulated recession rates. This procedure provides a first estimate on the potential risk a locality (here Collaroy/Narrabeen Beach) may face due to the impacts of sea-level rise and/or coastal storms. Overall, the modelling outcome suggests that long-term erosion problems associated with rising sea level are less significant in comparison with those impacts associated with short-term coastal storm events for Collaroy/Narrabeen Beach. 相似文献
464.
R. G. Donald 《运输规划与技术》2013,36(3):149-158
This paper discusses the need for a new approach to urban transportation modelling in recognition that at least in medium sized towns the choice of model is largely dominated by car availability. 相似文献
465.
Canada’s west coast has been a hotspot of environmental conflict, most recently in defense of climate action and natural places under threat by energy development. This study examined sense of place as a source of tension in conflicts sparked by two energy proposals. The Bute Inlet run-of-river hydroelectric project would power British Columbia’s remote Central Coast, and the Trans Mountain pipeline expansion would transport bitumen from Alberta’s oil sands to tankers for export. Surveys, interviews, and mapping were used to investigate the depth and character of participants’ sense of favorite places and places expected to be affected by the projects, with appreciation, concern, and responsibility for nature as organizing themes. We discovered a regional, nature-centric sense of place on the south coast, and a sense of place among Albertans linked to that province’s oil and gas economy and its reputation as Canada’s chief breadwinner. Ties to natural places were found to underpin environmental advocacy by tapping into deep place connections as well as place connections conveyed through network ideologies and the protests themselves. We outline for consideration key characteristics of a regional sense of place, and offer ways to mitigate place-based economy versus environment conflicts. 相似文献
466.
Ceyhun Güven 《Maritime Policy and Management》2019,46(2):201-216
Container transportation plays a critical role in the global shipping network and container terminals need to improve their operations to increase efficiency. Storage yard of a container terminal is a temporary area where the containers stay until they are shipped to their next destination. We concentrate on increasing the efficiency of the storage yard by developing online stacking policies for each incoming container. An unproductive move of a container, performed to reach another container stored underneath, is called reshuffling. The objective in container stacking problem is to minimise the number of reshuffles, thereby increasing the efficiency of terminal operations. Additional weight-related operational constraints bring additional complexity to the online stacking decisions. We propose a mathematical model for the optimal online assignment of an incoming export, transit, import or empty container. We also propose an optimal online stacking policy and compare it with a random policy through simulation. Additionally, lower bounds for the performance measures are obtained through simulation by relaxing the operational constraints of the problem in a third stacking policy. We present and discuss the computational results in terms of four main performance measures. 相似文献
467.
流固耦合问题较为复杂,通常难以通过理论推导求得,而数值模拟则能提供一种有效的解决方案,并被广泛用于船舶与海洋工程领域。流固耦合数值方法根据其网格离散方式,可以分为贴体网格方法、非贴体网格方法、重叠网格方法和粒子类方法 4类,对这4类方法的特点及研究进展进行概述并总结得出:贴体网格方法和重叠网格方法均能精确捕捉界面的变形和演化,适合高雷诺数流动问题,在考虑结构变形时一般采用贴体网格方法,而考虑复杂几何形状的刚体运动时则常采用重叠网格方法;非贴体网格方法能够避免网格的更新操作,使计算较为简单,目前多用于模拟流动控制、水下柔性仿生航行器的研发以及多体运动干扰等问题;粒子类方法因其固有的拉格朗日属性,在模拟涉及自由液面剧烈变形、砰击、爆炸等强非线性流固耦合问题中发挥着重要作用。不同的流固耦合问题属性决定了不同方法的适用性,如何选取适合的数值方法,同时结合各类方法的优势开发新的计算方法以应对更为复杂的问题,是流固耦合算法开发的重要发展方向。 相似文献
468.
The origin–destination matrix is an important source of information describing transport demand in a region. Most commonly used methods for matrix estimation use link volumes collected on a subset of links in order to update an existing matrix. Traditional volume data collection methods have significant shortcomings because of the high costs involved and the fact that detectors only provide status information at specified locations in the network. Better matrix estimates can be obtained when information is available about the overall distribution of traffic through time and space. Other existing technologies are not used in matrix estimation methods because they collect volume data aggregated on groups of links, rather than on single links. That is the case of mobile systems. Mobile phones sometimes cannot provide location accuracy for estimating flows on single links but do so on groups of links; in contrast, data can be acquired over a wider coverage without additional costs. This paper presents a methodology adapted to the concept of volume aggregated on groups of links in order to use any available volume data source in traditional matrix estimation methodologies. To calculate volume data, we have used a model that has had promising results in transforming phone call data into traffic movement data. The proposed methodology using vehicle volumes obtained by such a model is applied over a large real network as a case study. The experimental results reveal the efficiency and consistency of the solution proposed, making the alternative attractive for practical applications. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
469.
Transportation - Informal minibus services dominate public transportation in Lagos, Nigeria. Local, state, and federal government entities in Nigeria have historically only been able to provide... 相似文献
470.
Constant velocity universal joints play a very important role in automotive drivelines. The traditional development method,
based on a physical prototype and experimenting, is time consuming and costly. This test-based method does not easily identify
rational design clues. Therefore, a virtual product development method, which is based on dynamics modeling and simulation,
is necessary. Virtual prototyping for a universal joint has been developed using the simulation software package MSC.ADAMS.
Dynamics simulation has been performed to predict and evaluate joint behaviors. This virtual product development method has
been implemented by the WanXiang Group Co., which is one of the most famous Chinese automotive component manufacturers. 相似文献