基于CVT的混联式电动汽车动力切换平稳性研究

针对四轮驱动越野车提出了一种基于金属带式无级自动变速器(CVT)的混联式结构,其动力切换平稳性是这种混联式电动汽车必须解决的关键技术之一。通过发动机、电机、离合器和CVT的协调控制可以使系统在驾驶员发出加速命令时快速响应以及在模式切换时平稳,这将保证驾驶员在车辆切换过程中没有异常感觉。     

To fully automate or not? Investigating demands and willingness to pay for autonomous vehicles based on automation levels

We review the literature on the motivators of consumers’ purchasing decisions regarding autonomous vehicles (AVs), focusing on environmental awareness, vehicle types, concerns about accidents, and merits. The willingness to buy (WTB) and willingness to pay (WTP) for AVs have been extensively studied. However, it is imperative to broaden the outlook and consolidate the existing knowledge base. Although the WTB and WTP for AVs have been studied, automation-level preferences have been underresearched. Based on more than 150,000 observations, we construct a choice model and calculate the WTP for each level of automation. Our results show that there is a disparity between people's WTB and WTP according to the automation level. In particular, we find that the coefficients regarding FAVs’ benefits and accidents significantly exceed those related to environmental concerns. Such results indicate that practical benefits and concerns influence AV demand and WTP to a greater extent than environmental awareness. Our model results indicate a disparity between WTB and WTP for AVs that mostly derives from the different types of environmental concerns, concerns about accidents, and perceived benefits from these automobiles. Our results urge policies according to which governments and companies closely examine consumers who exhibit WTB-WTP disparities. Issues relating to demand patterns, WTP, and a suitable policy framework are discussed.     

基于VISSIM仿真的主干道支路接入控制方式研究

选取VISSIM交通仿真软件,根据实测的主干道交通数据,对软件的交通模型参数进行标定及验证,在此条件下以主路延误及支路延误为控制指标,以双向六车道中央分隔带主干道为对象,可得出在不同流量条件下支路接入的最佳控制方式。     

石太客运专线列车开行方式改变降低电费方案

根据石太客运专线列车开行方案变化,引起牵引变压器容量需求减小情况,提出几种降低电费的方案,可供相关线路参考借鉴。     

泥岩边坡的病害特征及破坏模式研究

高边坡问题在基础建设的发展过程中不断出现,尤其是泥岩边坡问题。文中通过分析泥岩边坡6种病害坡体结构:顺倾层状结构、反倾层状结构、陡倾层状结构、基座式上软下硬结构、交叉式楔形结构,得出了泥岩边坡在不同坡体结构下可能的破坏方式;最终归纳总结出了5种典型的泥岩边坡破坏模式:风化剥落、楔体破坏、倾倒破坏、滑移-拉裂破坏、牵引式滑动破坏。     

基于柔刚体模型的高速车轮振动辐射噪声研究

随着轨道车辆速度的不断提升,其运行噪声已成为城市噪声的主要来源之一,在传统的动力学模型基础上,引入了柔性轮对模块,将车轮辐射噪声与模态结合起来,并对车轮结构进行优化设计,以期为低噪声车轮的研究提供参考依据。     

船舶中压电力系统中性点接地方式研究

对船舶中压电力系统的几种中性点接地方式,作了较为详细地分析.对于适用于船舶中压电力系统的不接地系统和经高阻接地系统各自的优缺点作了比较.从而得出当系统对地电容电流大于一定的值后,采用中性点经高阻接地系统较为合适.这样可以大大降低电流的等级,在大大降低配电板成本的同时,也节约了大量的电缆,提高系统的安全可靠性.     

出行链视角下城市轨道交通接驳方式联合选择模型

以城市轨道交通出行方式链为例,针对城市轨道交通两端的接驳方式,构建基于交叉巢式Logit(CNL)模型的城市轨道交通出行链联合选择模型。模型从出行全过程角度,将轨道交通两端的接驳方式纳入一个模型里进行联合选择。模型选取出行者社会经济特征,发生端出行特征,到达端出行特征三类特征变量,建立联合概率模型,对特征变量进行标定。模型结论显示:(1)以到达客流为主的城市轨道交通站点对于交通接驳便捷程度的敏感性更高;(2)公交接驳方式转化为小汽车接驳的可能性更高。对于揭示城轨接驳规律,优化轨道接驳系统具有实际意义。     

非线性静力分析需求谱建立方法的两点改进

非线性静力分析是对结构在罕遇地震作用下进行弹塑性变形分析的一种方法,目前广泛应用于结构的抗震性能评估中.非线性静力分析的研究目前有若干分析方法,这些方法在结构能力曲线建立的方法上是相同的,即首先建立力-位移曲线,然后转化为承载力谱,但是在需求曲线的建立上各有不同.通过介绍几种典型的非线性静力分析需求谱建立方法,指出其和原有的需求谱建立方法的不同和改进之处.     

A general scaled model design method of stiffened plate subjected to combined longitudinal compression and lateral pressure considering the ultimate strength and collapse modes

A general and efficient scaled method for stiffened plates subjected to combined longitudinal compression and lateral pressure is proposed based on slenderness, simply by adjusting the number of stiffeners. The design method makes it easier to determine the dimensions of the scaled model for a given scale ratio compared with the previously proposed method. The emphasis is on the influence of the plate slenderness, the column slenderness, and the non-dimensional parameter of the lateral pressure on the ultimate strength. By maintaining the consistency of the plate slenderness and column slenderness, the proposed method is applicable for designing scaled models with materials of different yield stresses and Young's moduli. A similar effect of the lateral pressure on the ultimate strength of the prototype and scaled models is achieved by maintaining the non-dimensional parameter. In addition, the applicability of the scaled method to the initial deflection is considered, which provides a reference for similar models. The similitude of the scaled method is verified for several typical buckling modes, including the beam–column, tripping, web and overall collapse modes. Given the numerical results, the proposed general and fast scaled method can provide reasonable dimensions of scaled stiffened plates subjected to combined loads.