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431.
Kristjan Tabri Jukka Määttänen Janne Ranta 《Journal of Marine Science and Technology》2008,13(1):71-84
This study was initiated due to the lack of experimental data on ship collisions. The feasibility of model-scale ship collision
experiments was examined and a series of model-scale ship collision experiments is presented. The theoretical background for
the analysis of experiments is given together with the principles of scaling. Proper scaling should assure physical similarity
to the large-scale experiments conducted in the Netherlands. The Froude scaling law was followed, resulting in the improper
scaling of some forces: the effects of this are discussed. The study concentrates on the dynamics of collisions. The structural
response, properly scaled from the large-scale experiments, was modelled using polyurethane foam as the ship’s side structure.
The collision process was analysed and the results of model-scale tests, large-scale experiments, and a simple analytical
model were compared, showing that there was both quantitative and qualitative agreement in the results of the experiments
conducted at different scales. The analytical model yielded good quantitative assessment of the deformation energy. 相似文献
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This study investigated the wheel-lift and roll-over derailment mechanisms caused by train collisions using a precise virtual testing model (VTM) of a Korean high-speed train. The VTM was a complex, nonlinear finite element model composed of the shell, beam, solid, spring, and surface contact elements for the car body, bogies, suspensions, and wheel–rail interfaces. The VTM was validated by checking the errors in the total energy and the dynamic responses of the spring elements. To achieve a quick, dynamic relaxation of the dead weight of the VTM before the collision analysis, the artificial damping method and the artificial force method were introduced and numerically evaluated. The surface-to-surface contact model from commercial software, Ls-Dyna, was applied to the VTM in order to simulate the derailment mechanisms caused by collision accidents. The numerical analyses of the VTM colliding with a large deformable obstacle or a rigid wall revealed for the first time that a mixed slip/roll-over-type derailment mechanism generally occurs. Furthermore, the simulation results were consistent with the results from a simplified theoretical derailment model of a wheel set. 相似文献
435.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):663-674
Override simulations of two train units in frontal collision have been carried out using multi-body dynamics. The aim of this paper is to investigate the possible factors influencing the overriding behaviour throughout frontal collisions. In addition to the initial vertical offset defined in the standard EN 15227, the pitching motion of vehicles has a great effect on the overriding phenomenon. It depends on several factors, such as collision mass, pitching frequency, height of the centre of mass above the rail level. In this paper, it has been shown that the overriding phenomenon is more sensitive to variations in pitching frequency and height of the centre of mass, compared with the factor of the collision mass. Moreover, it has been demonstrated from simulation results that a 200-kN vertical force is required for the combined anti-climber devices (100 kN for each side anti-climber) to constrain the vertical relative motion between crashed train units. 相似文献
436.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1658-1680
A number of driver models were fitted to a large data set of human truck driving, from a simulated near-crash, low-friction scenario, yielding two main insights: steering to avoid a collision was best described as an open-loop manoeuvre of predetermined duration, but with situation-adapted amplitude, and subsequent vehicle stabilisation could to a large extent be accounted for by a simple yaw rate nulling control law. These two phenomena, which could be hypothesised to generalise to passenger car driving, were found to determine the ability of four driver models adopted from the literature to fit the human data. Based on the obtained results, it is argued that the concept of internal vehicle models may be less valuable when modelling driver behaviour in non-routine situations such as near-crashes, where behaviour may be better described as direct responses to salient perceptual cues. Some methodological issues in comparing and validating driver models are also discussed. 相似文献
437.
船舶避碰中驾驶员的心理紧张状态与其人为失误 总被引:1,自引:0,他引:1
本文从心理学和生理学的角度,剖析了船舶避碰中驾驶员的心理紧张状态及其对人为失误的影响,提出了缓解紧张状态、减少人为失误的措施,为研究碰撞海事提供了一个新的途径。 相似文献
438.
在充分肯定了《内河避碰规则》的主体框架的基础上,针对目前反映比较突出的一些问题做了细致的分析,例如一些条款不够全面;有些条款用词陈旧,不够准确;对操限船、限于吃水船及失控船的概念没有提及;将内河的主要运输船型——拖带或顶推船没有纳入操限船的范畴等,对当前内河的航行安全产生了不利影响。针对这些问题,分别提出了新的建议。 相似文献
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