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排序方式: 共有403条查询结果,搜索用时 15 毫秒
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针对高压共轨柴油机,分析怠速控制原理,提出高压共轨柴油机怠速控制的标定方法.运用INCA标定软件,对2.5L柴油机进行怠速控制参数标定试验,使柴油机怠速稳定,速度响应较快,取得了较好的效果. 相似文献
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结合离散小波变换、动态系统理论及随机过程理论,建立了以尺度为变量的多尺度随机动态模型,并给出状态基于多尺度随机动态模型的多尺度递归数据融合算法,实现了在状态基于全局观测信息的优化估计值。该算法可以在无状态模型情况下进行数据融合,适用于难以获得或获得的状态模型不精确的情况。将此方法用于陀螺信号处理中,通过不同尺度下陀螺观测值的融合,陀螺信号的精度有明显的提高。仿真和实验均证明该算法是一种有效的数据融合算法。 相似文献
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在以批量生产为特征的汽车零部件行业,凸轮轴、万向节、轴承、气门和活塞销等重要零件的表面品质是产品质量的一项重要指标,但传统的测试方法却难以满足准确和快速检测的要求。文章对零件的表面品质及其惯用检测手段进行了描述,着重推出了一种新颖和高效的磨削烧伤检测方法——磁弹法。文章介绍了这种方法的工作原理,以及在这基础上研制的专用仪器的基本结构和组成,叙述了应用磁弹法时的评定特征值mp和仪器的定标,并通过所举实例予以说明。 相似文献
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Christine Funfschilling Guillaume Perrin 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(7):1062-1086
ABSTRACTThis paper presents a review of various works that highlight the importance of introducing the variability of the road-track/vehicle system into dynamic simulations as soon as this latter is meant to be predictive. The first section of the paper presents the Uncertainty Quantification, Verification and Validation method (UQ-VV). This latter proposes tools to model uncertainties, to associate a confidence to the prediction of quantities of interest and to estimate the probability of occurrence of different scenarios. The method is illustrated by various examples mainly from the rail domain but also from the road sector. The second section summarises application examples of predictive modelling, robust optimisation and calibration. 相似文献
167.
Bayesian calibration of mechanistic aquatic biogeochemical models and benefits for environmental management 总被引:1,自引:0,他引:1
George B. Arhonditsis Dimitra Papantou Weitao Zhang Gurbir Perhar Evangelia Massos Molu Shi 《Journal of Marine Systems》2008,73(1-2):8-30
Aquatic biogeochemical models have been an indispensable tool for addressing pressing environmental issues, e.g., understanding oceanic response to climate change, elucidation of the interplay between plankton dynamics and atmospheric CO2 levels, and examination of alternative management schemes for eutrophication control. Their ability to form the scientific basis for environmental management decisions can be undermined by the underlying structural and parametric uncertainty. In this study, we outline how we can attain realistic predictive links between management actions and ecosystem response through a probabilistic framework that accommodates rigorous uncertainty analysis of a variety of error sources, i.e., measurement error, parameter uncertainty, discrepancy between model and natural system. Because model uncertainty analysis essentially aims to quantify the joint probability distribution of model parameters and to make inference about this distribution, we believe that the iterative nature of Bayes' Theorem is a logical means to incorporate existing knowledge and update the joint distribution as new information becomes available. The statistical methodology begins with the characterization of parameter uncertainty in the form of probability distributions, then water quality data are used to update the distributions, and yield posterior parameter estimates along with predictive uncertainty bounds. Our illustration is based on a six state variable (nitrate, ammonium, dissolved organic nitrogen, phytoplankton, zooplankton, and bacteria) ecological model developed for gaining insight into the mechanisms that drive plankton dynamics in a coastal embayment; the Gulf of Gera, Island of Lesvos, Greece. The lack of analytical expressions for the posterior parameter distributions was overcome using Markov chain Monte Carlo simulations; a convenient way to obtain representative samples of parameter values. The Bayesian calibration resulted in realistic reproduction of the key temporal patterns of the system, offered insights into the degree of information the data contain about model inputs, and also allowed the quantification of the dependence structure among the parameter estimates. Finally, our study uses two synthetic datasets to examine the ability of the updated model to provide estimates of predictive uncertainty for water quality variables of environmental management interest. 相似文献
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阿布森法沥青回收试验探讨 总被引:4,自引:1,他引:3
结合广佛高速公路大修沥青再生课题沥青回收的大量试验,对阿布森试验方法进行了分析、总结,取得了较好的效果. 相似文献