山碴料路基的强度机理研究

通过引入颗粒形状修正系数，得到山碴料的二维应力应变关系。影响山碴料路基力学性能的主要因素为孔隙比、形状修正系数及刚度比例系数等参数，其中形状修正系数越大，孔隙比越小，山碴料路基的力学性能越好，反之越差。     

降雨方向与坡面侵蚀临界坡度的理论分析

对工程边坡进行绿色防护的初期,降雨侵蚀是造成边坡绿色防护层破坏的重要因素.在考虑了降雨方向对坡面侵蚀的影响条件下,当雨滴下落方向与垂直方向的夹角为β时,从理论上证明降雨侵蚀的临界坡度在迎风坡面坡度为47.2° β/2,背风坡面为47.2°-β/2.     

天津市滨海新区市政建设简介

该文介绍了天津市滨海新区市政建设的基本情况及建设方案。     

隧道盾构机进出洞施工技术

盾构的进出洞工序是盾构法建造隧道的关键工序。该文阐述了盾构进出洞施工的重要性,介绍了稳定正面土体、基座及后座的设置、洞口间隙的密封等施工技术。     

抛石层灌注桩施工新工艺的应用

抛石层灌注桩施工工艺的应用填补了国内灌注桩施工的一项空白,它具有操作简便、确保成孔质量、设备简单、工期短、成本低等特点。取芯注浆是该工艺的核心工序。它的应用为今后同类地质条件下的灌注桩施工提供了经验。     

An algorithm for finding reasonable paths in transit networks

In this paper, reasonable paths in transit networks are defined as possible paths that satisfy the acceptable time criterion and transfer‐walk criterion. A recursive algorithm for finding all of the reasonable paths in a transit network that does not involve a rapid increase in program run‐time with network size is presented. Realistic transit networks in Hong Kong and Guangzhou were selected as case studies of the different phases of the development of a trip planning system. Transport planning practitioners and potential users were invited to test the system to evaluate its performance. The results of the prototype evaluation were satisfactory, and the viability of the system as a useful tool for supporting decision‐making has been confirmed by the positive feedback that was obtained from survey questionnaires.     

变速比转向器齿轮副的机理分析

本文运用啮合原理分析方法给出了变速比转向器齿条齿扇传动的啮合线方程、齿扇的齿廓方程,导出了锥形齿扇被切削时小端不根切、大端不尖的变位系数和齿扇几何尺寸计算公式。     

燃油顺序喷射电控系统在微型汽车汽油发动机上的应用

本文研制和开发一种能实现多点燃油顺序喷射的电控系统，系统以８０Ｃ５５２为控制单元ＥＣＵ的主芯片。根据进气绝对压力和转速，采用速度密度法间接测量进气量，试验表明，配用该系统后，与原机相比，动力性，经济性和排放性能有明显改善，本文较为详尽地论述了控制系统的组成，原理及顺序喷射的实现方法，并给出试验结果。     

Optimal Preview Control of a Two-dof Vehicle Model Using Stochastic Optimal Control Theory

An optimal preview control algorithm is applied to a two degree of freedom(dof) vehicle model travelling with constant velocity on a randomly profiled road. The road roughness is modelled as a homogeneous random process being the output of a linear first order filter to white noise. The input from the road irregularity is assumed to be measured at some distance in front of the vehicle and this measured infonnation is utilized by the active controller to prepare the system for the ensuing input. The preview control algorithm is obtained by minimizing a quadratic performance index and by describing the average behaviour of the system by the covariance matrix of the vehicle response state vector. Results are presented for full state feedback and significant improvements in sprung mass acceleration, suspension working space and road holding are observed.     

用双级谐波传动实现汽车发动机凸轮轴调相的研究

汽油机采用ＶＶＡ可改善怠速稳定性，提高中低速外特性扭矩，往往也有一定的节油效果。但ＶＶＡ机构研制难度很大，目前只有个别机构实用。作者研制了一个采用双级谐波传动的调相机构。试验表明，该机构能圆满实现调相功能，其长期工作的可靠性也经受了一定考验，考察了调相对发动机充量系数的影响，计算和实测结果基本一致，在全部转速范围内，充量系数都有提高。