机车柴油机微机检测系统可靠性的研究

本文在分析机车柴油机微机检测系统工作环境条件的基础上,提出了抑制电磁干扰,提高检测系统可靠性的措施。     

车身CAGD中散乱数据的曲面拟合

根据车身外形曲面测量和拟合的要求,本文分析了散乱数据曲面拟合的Ｓｈｅｐａｒｄ、Ｂ－ｓｐｌｉｎｅ最小二乘法及Ｔａｙｌｏｒ逼近方法的各自特点,推导了计算模型并建立了软件系统,给了了用于车身ＣＡＧＤ的实例。     

用三维模型计算整体活塞机械变形及应力的研究

本文以16V240ZJ型柴油机结构改进后的整体薄壁球铁活塞为例,用三维有限元模型计算了在最大气体爆发压力作用下,其机械变形和应力的分布规律,研究了一些结构参数的变化对其应力分布的影响,并对活塞顶部应力较高的部位进行了二次细算,揭示了销座部分的结构非轴对称性对活塞顶部环向各点应力分布规律的影响,为活塞的改进设计提供了依据。     

高速客车非线性模型动力学分析

本文建立客车动力学的非线性模型,分析各种非线性结构,悬挂参数对车辆动力性能的影响,着重讨论高速车辆的横向稳定性和在轨道随机不平顺激扰下的运行平稳性。本文还应用研究结果优选出适合我国高速铁路运行的车辆参数匹配。     

Field Measurements and Pullout Tests of Reinforced Earth Retaining Wall

In this paper, field measurements and pullout tests of a new type of reinforced earth retaining wall, which is reinforced by trapezoid concrete blocks connected by steel bar, are described. Field measurements included settlements of the earth fill, tensile forces in the ties and earth pressures on the facing panels during the construction and at completion. Based on the measurements, the following statements can be made : ( 1 ) the tensile forces in the ties increased with the height of backfill above the tie and there is a tensile force crest in most ties; (2) at completion, the measured earth pressures along the wall face were between the values of the active earth pressures and the pressures at rest; (3) larger settlements occurred near the face of the wall where a zone of drainage sand and gravel was not compacted properly and smaller settlements occurred in the well-compacted backfill. The results of field pullout tests indicated that the magnitudes of pullout resistances as well as tensile forces induced in the ties were strongly influenced by the relative displacements between the ties and the backfill, and pullout resistances increased with the height of backfill above the ties and the length of ties.     

梁应辰院士谈三峡工程

1引言 今年6月,举世瞩目的三峡工程二期工程完工,三峡工程进入通航发电阶段.作为集政治、经济与交通等因素于一体的重大系统工程项目,该项目的建设无论对交通运输业还是对系统工程界均有着重大影响.为此,本刊特约记者最近专程采访了最早参与三峡工程建设的专家之一、三峡工程质量检查专家组成员、中国工程院梁应辰院士.     

构建海船驾驶专业实践教学体系的建议

本文根据海船驾驶专业教学的职业特点，提出了构建实践教学体系的六个组成部分，并结合航海教学的实际，建议从教学计划、教学投入、实训教师的队伍建设、教学手段和考核评估、实训教材建设等方面推进改革。     

NEW HAUSDORFF DISTANCE-BASED VEHICLE LOCATION

Objective To realize accurate localization of moving vehicles from single monocular intensity image.Methods The new modified Hansdorff distance(M2HD) was adopted, which used dominant points instead of edge maps as features for measuring similarity between image and model projection. Modified simulated annealing (MSA) algorithm was used to find optimum localization parameters. Results M2HD reduces the computational complexity,and improves the matching precision. Furthermore, MSA can fast find global optimum instead of getting into partial one because of its high parallel and robust performance. Conclusion Experiments confirm that the combination of MSA and M^2 HD can effectively localize the vehicles that are changed both in translation and rotation     

Research on the Variable Steering Ratioof Four-Wheel-Steering Vehicle

The steering characteristic of afour-wheel-steering vehicle is numerically simulated for in-depth research of the handling stability offour-wheel steering．The research results show that the deteriorating tendency of the steering stability due to the increase of the vehicle speed is improved obviously in the case of four-wheel steering．The approach of variable steering ratio is discussed.The use of the variable steering ratio can not only raise the steering stability of vechicles at high vehicle speed，but also reduce the dicomfort and steering burden of drivers；and hence is helpful for the subjective evaluation of four-wheel steering vehicles．