Who will buy electric vehicles? Identifying early adopters in Germany

Electric vehicles (EVs) have noteworthy potential to reduce global and local emissions and are expected to become a relevant future market for vehicle sales. Both policy makers and car manufacturers have an interest to understand the first large EV user group, frequently referred to as ‘early adopters’. However, there are only a few empirical results available for this important group. In this paper, we analyse and discuss several empirical data sets from Germany, characterising this user group from both a user and a product perspective, i.e. who is willing to buy an EV and who should buy one. Our results show that the most likely group of private EV buyers in Germany are middle-aged men with technical professions living in rural or suburban multi-person households. They own a large share of vehicles in general, are more likely to profit from the economical benefits of these vehicles due to their annual vehicle kilometres travelled and the share of inner-city driving. They state a higher willingness to buy electric vehicles than other potential adopter groups and their higher socio-economic status allows them to purchase EVs. In contrast to this, inhabitants of major cities are less likely to buy EVs since they form a small group of car owners in general, their mileage is too low for EVs to pay off economically and they state lower interest and lower willingness to pay for EVs than other groups. Our results indicate that transport policy promoting EVs should focus on middle-aged men with families from rural and sub-urban cities as first private EV buyers.     

基于多折线外特性模型的直流牵引供电系统稳态短路计算

直流牵引供电网络故障分析对城市轨道交通牵引供电系统设计有着重要的作用.针对整流机组,采用多段折线的外特性模型,使用变化理想电压源、内阻的戴维南等效电路模拟,并通过迭代的方法确定短路时的工作区间.建立了包括杂散电流收集网在内的供电系统仿真模型,可较准确地仿真短路时各整流机组负荷以及接触网、钢轨与杂散电流收集网电位等的变化情况.     

α—γ系爆炸焊接复合板加热后碳迁移规律

对α－γ系爆炸焊接复合板加热后碳迁移引起的增碳层宽度的变化规律进行了研究，得出了增碳层宽度的变化与Ｔ和t关系的数学模型，该模型的试验结果与试验数据有良好的一致性。     

硅烷防护对混凝土抗氯离子渗透性的影响

通过室内快速试验和实海暴露试验,研究硅烷防护对混凝土氯离子渗透性的影响。研究表明:硅烷浸渍层能够有效降低氯离子对混凝土的侵蚀,减小混凝土氯离子扩散系数和表面氯离子浓度,其中氯离子扩散系数降低幅度在50%以上,可显著提高混凝土结构使用寿命;且硅烷浸渍层能够减小处于干湿交替区域混凝土结构"对流层"的深度。     

基于信息扩散理论的浙江通航环境风场风险分析

以浙江省各气象观测站风场数据为基础,根据信息扩散理论分析了浙江省及其沿海地区最大风速、大风天数的风险概率及其空间分布.研究表明:浙江内陆大部分区域10a一遇最大风速为15～20m/s,中部沿海为30～40m/s;7～9月是沿海大风发生风险概率较高的月份,嵊泗站冬夏季节9级以上大风概率较低,春秋季节风险概率较高;7级以上大风6d/月和12d/月的风险概率有比较明显的季节性;嵊泗站在春季、大陈岛站在10月至次年3月相比其他月份风险概率较高.     

自动变速器技术状况对稳态工况法检测的影响分析

基于稳态工况法特点和自动挡车辆排气污染物超标现状,分析了自动变速器技术状况对稳态工况法检测的影响,指出在排气污染物超标车辆治理实践中应注重自动变速器的检查与性能恢复,对制定针对性的预防和治理措施具有指导意义。     

溶液型浆体在岩溶裂隙中运移的动力学研究

从浆液扩散理论的基本假设出发,综合考虑岩溶区被注介质和浆液扩散特征,在总结前人研究成果的基础上,推导出浆液在贯通岩溶裂隙或者管道中扩散时所须满足的动力学通用控制方程。在考虑溶液型浆体特性、被注介质特征和扩散过程的前提下,对通用动力学控制方程进行合理简化,获得适用于溶液型浆体在岩溶裂隙和管道网络中扩散的动力学控制方程。基于有限体积法理论,借助于HQUICK、Central Difference、Crank-Nicolson和Adams-Bashforth等离散格式对控制方程完成数值离散工作,然后采用压力泊松方程法对其完成数值求解工作,从而为研究岩溶区浆液扩散过程的软件开发和数值模拟工作提供理论基础,开创采用计算流体动力学理论方法对溶液型浆液在岩溶裂隙和管道介质中的扩散研究的新途径。     

Boost DC/DC的低压启动能力

为了准确预测Boost DC/DC低压启动能力,采用稳态分析方法,分析了电流负载、寄生参数、功率开关饱和电流及导通阻抗、开关频率、启动电路最低工作电压等因素对Boost DC/DC低压启动能力的影响,提出了预测Boost DC/DC恒流负载下最小启动电压的解析模型.将该模型应用于采用0.6μm CMOS工艺的Boost DC/DC设计中,模型计算结果相对HSPICE仿真结果的最大误差为4.5%.本模型可推广至恒定电阻负载的情况.     

考虑竖向预应力扩散影响的箱梁腹板预压应力计算

竖向预应力筋对箱梁腹板产生的竖向压应力计算,关系到腹板主拉应力计算和抗裂问题,现行桥梁设计规范有关预压应力的计算公式没有考虑预应力在锚下的扩散。本文从弹性理论的解析解出发,讨论竖向预应力下考虑应力扩散的箱梁腹板压应力计算问题,最后给出竖向预应力筋合理间距和扩散角的计算公式。     

沿海地区软弱下卧层地基处理方式浅析

沿海地区的软弱土以及不良土是工程建设中常遇到并且比较棘手的问题,特别是处理场地受限于轨道交通等地下构筑物限界时,难度更大.拟处理的软卧地基为江苏沿海某城市规划轨道交通线上的软弱地基,由于地基下埋设远期规划的轨道交通线,处理深度受限,最终处理方式确定为咬合排桩方式,设计验算采用实体深基础方法并运用MIDAS gts 软件进行复核性验算.