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991.
M. M. Chatillon L. Jezequel P. Coutant P. Baggio 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(11):817-839
This paper presents a design methodology for the mechanical systems entitled First Design. It is based on a hierarchical organisation of the design, taking into account the notion of robustness at an early phase of the project. The aim is to improve the quality of the system in order to make it robust, less sensitive to the variability of the external parameters and design parameters. We distinguish two main stages of the design cycle: one concerning functional parameters and another concerning physical parameters. The methodology is based on simplified models, on sensitivity analysis and on robust multi-objective optimisation. As an example, the methodology will be applied to the optimisation of vehicle suspension system design parameters. For each stage of the hierarchical design, adapted simplified models, sensitivity analyses and optimisation processes will be studied and applied to our vehicle suspension system. 相似文献
992.
Validating the results of a route choice simulator 总被引:1,自引:0,他引:1
Peter Bonsall Paul Firmin Monica Anderson Ian Palmer Peter Balmforth 《Transportation Research Part C: Emerging Technologies》1997,5(6):15
This paper describes the validation of a route choice simulator known as VLADIMIR (Variable Legend Assessment Device for Interactive Measurement of Individual Route choice). VLADIMIR is an interactive computer-based tool designed to study drivers’ route choice behaviour. It has been extensively used to obtain data on route choice in the presence of information sources such as Variable Message Signs or In-Car Navigation devices. The simulator uses a sequence of digitized photographs to portray a real network with junctions, links, landmarks and road signs. Subject drivers are invited to make journeys between specified origins and destinations under a range of travel scenarios, during which the simulator automatically records their route choices. This paper describes validation experiments carried out during the period Summer 1994 to Autumn 1995 and reports on the results obtained. Each experiment involved a comparison of routes selected in real life with those driven under simulated conditions in VLADIMIR. The analysis included investigation of the subjects’ own assessment of the realism of the VLADIMIR routes they had chosen, a comparison of models based on the real life routes with models based on VLADIMIR routes, and a statistical comparison of the two sets of routes. After an extensive series of data collection exercises and analyses, we have concluded that a well designed simulator is able to replicate real life route choices with a very high degree of detail and accuracy. Not only was VLADIMIR able to precisely replicate the route choices of drivers who were familiar with the network but it also appears capable of representing the kind of errors made and route choice strategies adopted by less familiar drivers. Furthermore, evidence is presented to suggest that it can accurately replicate route choice responses to roadside VMS information. 相似文献
993.
The classical derivation of a traffic stream model (e.g. speed/concentration relation) from the equilibrium solutions of the Prigogine–Herman kinetic equation invokes the nontrivial assumption that the underlying distribution of desired speeds is nonzero for vanishingly small speeds. In this paper we investigate the situation when this assumption does not hold. It is found that the Prigogine–Herman kinetic equation has a one-parameter family of equilibrium solutions, and hence an associated traffic stream model, only for traffic concentrations below some critical value; at higher concentrations there is a two-parameter family of solutions, and hence a continuum of mean velocities for each concentration. This result holds for both constant values of the passing probability and the relaxation time, and for values that depend on concentration in the manner assumed by Prigogine and Herman. It is hypothesized that this result reflects the well-known tendency toward substantial scatter in observational data of traffic flow at high concentrations. 相似文献
994.
995.
本文分析控制系统的结构、原理及控制流程,提高未来对汽车零部试验台控制系统的一种发展方向,即通过智能化网络数据采集与过程控制系统,真正做到在办公室内控制现场设备,察看运行情况,记录运行过程并适时进行调整。基于Lonworks^TM技术的系统是一种可以实现从现场设备到用户操作的监控系统。 相似文献
996.
997.
基于意向调查数据的非集计模型研究 总被引:15,自引:1,他引:15
当交通系统中引入新的交通方式时,传统的基于实绩选择调查数据的交通需求预测方法对于方式分担预测将会无效。本文以新交通方式的分担率预测模型为研究对象,提出基于实绩选择调查和假设意向调查组合数据的非集计模型,对模型中各种交通方式的效用函数进行了深入研究,并以东直门至首都机场的轨道交通客流预测为例,进行了参数估计和轨道分担率预测。实例研究表明,模型能够较准确的预测出新交通方式的分担率。 相似文献
998.
小波变换在弯沉检测数据消噪中的应用 总被引:1,自引:0,他引:1
贝克曼梁由于其系统本身的缺陷在弯沉检测过程中常常会受众多误差和干扰的影响,从而造成弯沉检测值与真实值之间存在较大偏离,严重时甚至会对弯沉值的统计分布形式造成影响。针对这种情况,本文提出采用小波变换对受噪音不均匀干扰的弯沉检测数据进行消噪处理的方法,并对处理之后的数据与原始数据进行了分析和比对。结果表明:经过小波变换消噪处理的数据能较好地保持原始数据的统计学特性,且能使偏离正态分布的弯沉检测结果重新服从正态分布:小波变换能有效地剔除原始检测数据存在的不均匀分布的噪音信号。 相似文献
999.
1000.
城市快速路拥挤度判别方法研究 总被引:6,自引:2,他引:6
当前城市交通需求的大幅增长导致快速路的交通拥挤和交通堵塞现象普遍发生,对城市快速路的道路拥堵的服务质量的评价,传统的A~F级服务水平的评价标准显得粗糙。提出了与交通流三参数有关的拥挤度系数的概念,并针对快速路的实际状况,运用模糊数学中的综合评价方法,对城市快速路拥挤度进行判别。城市快速路拥挤度判别实例,通过拥挤度判别和服务水平判别的比较,说明了拥挤度判别的优越性。 相似文献