追求精细化的街道设计——《伦敦街道设计导则》解读

自20世纪90年代,英国的交通政策就在向整合交通和土地利用规划的方向努力。伦敦交通局于2004年发布了《伦敦街道设计导则》(以下简称《导则》),并于2009年修订。该导则作为"更好的街道"计划的一部分,对伦敦市区的街道项目具有重要的引导作用。首先通过叙述伦敦市街道形态与规划政策的演变,介绍《导则》的政策背景、概要内容及设计原则。从设计流程、材料面板、街道设计指引几个方面解析《导则》的特点。通过研究伦敦市的道路形态和街道设计现状,评述《导则》的落实与应用情况。最后,从全过程精细化指导、规范标准补充、街道设计理念转变三个方面总结《导则》对中国城市街道设计的借鉴意义。     

移动式安全座椅的乘员保护性能的研究

传统的座椅在汽车前碰撞中是不允许产生明显变形的,本文中提出了3种移动式的汽车安全座椅,它们可在汽车前碰撞时发生相应的变形,具有防止乘员下潜,消除安全带与乘员之间的初始间隙和降低胸部加速度的作用:立了使用3种移动式座椅和传统座椅的汽车前碰撞乘员动力学响应和损伤分析的仿真模型,并进行4种座椅的对比仿真.结果表明,与传统座椅和其它两种移动座椅相比,第一种移动式安全座椅对乘员头部、颈部和胸部具有较好的防护性能.     

Green-Naghdi theory, part A: Green-Naghdi (GN) equations for shallow water waves

In this work,Green-Naghdi (GN) equations with general weight functions were derived in a simple way. A wave-absorbing beach was also considered in the general GN equations. A numerical solution for a level higher than 4 was not feasible in the past with the original GN equations. The GN equations for shallow water waves were simplified here, which make the application of high level (higher than 4) equations feasible. The linear dispersion relationships of the first seven levels were presented. The accuracy of dispersion relationships increased as the level increased. Level 7 GN equations are capable of simulating waves out to wave number times depth . Numerical simulation of nonlinear water waves was performed by use of Level 5 and 7 GN equations, which will be presented in the next paper.     

通过形状差异修正模式方法进行的损伤识别试验(英文)

An experimental program was undertaken to test the feasibility to detect the occurrence of structural damage using a modified mode shape difference technique. The vibration response of a steel beam fixed at one end and hinged at the other was obtained for the intact and damage conditions. Modal analysis was performed to extract the frequencies and mode shapes. The method shows a good potential in detection of occurrence and location of damage.     

集束塔式立管总体强度分析(英文)

Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.     

利用微米尺度计算机断层扫描技术重建水泥石三维微观结构

水泥基材料的微观结构与其性能存在着密切关系.利用微米尺度计算机断层扫描技术这种基于X射线技术及数学方法的测试手段,研究了水泥石的微观结构.通过对选定的水泥基材料局部区域进行X射线逐层扫描之后得到系列二维灰度图像,再通过数学方法和软件将其依次叠加重构成三维图像;然后基于孔、水化产物和未水化水泥熟料颗粒灰度阈值之不同,将其分别标识并分割出来进行单独研究,并可进一步计算其各自体积分数、在空间的分布状态等.     

采用模块化标准部件的Volkswagen公司欧6柴油机

在采用模块化标准部件的欧5柴油机进入市场后,Volkswagen公司的首要任务是采取进一步的机内措施并集成降氮氧化物排气后处理装置开发欧6柴油机。这种模块化基础已成为附加的发动机措施,并且,可选用存储式氮氧化物催化转化器或选择性催化还原技术。     

全球轻型车统一测试程序对乘用车CO2排放的影响分析

截至2017年，欧盟轻型车排放污染物和油耗的型式核准程序是新欧洲行驶测试循环(NEDC)。该测试在底盘测功机上进行。     

在整机上平均喷油器的新方法

一种新开发的硬件在环（HiL）方案与一种高柔性输出级电控单元相结合，使得现代汽车公司的研发人员能在最短时间内以最少的技术费用在整机上试验共轨喷油器。     

液化石油气发动机直接喷射的超临界压缩方案

液化石油气（LPG）较高的蒸汽压力可导致燃油系统高压和低压部分中的燃料蒸发，随之就会导致燃料密度大幅降低而使发动机停机。