吴文俊与数学机械化

机器证明的思想可以回溯到17世纪的Descartes与Leibnize,20世纪初Hilbert更明确地提出了公理系统的机械化判定问题,但是,随后的种种努力都未能使机器证明取得本质的进展。近20年来,吴俊继承并发展了中国古代的数学思想,在定理机器证明上开创了以多项式组零点集为基本点的消元方法;吴俊的数学机械化方法已在物理规律的发现,机器人学,计算机视觉以及促进现代数学研究等重大高科技的前沿领域实现了成功的应用。数学机械化研究的兴趣,是中国当代数学发展中一个引人瞩目的具有中国传统特色的新里程碑。     

城轨运营中断下应急公交车辆调度模型

随着城市轨道交通运营网络规模扩大和客流迅速增长,运营中断下公交应急联动问题日益被重视.针对城轨运营中断下的公交桥接疏运问题,提出一种灵活调度策略,允许车辆服务于不同的桥接路径,以最小化总疏散时间和平均乘客延误为目标,建立基于灵活路径模式下的多目标应急公交车辆调度模型,使用理想点法和遗传算法进行求解,并进行实例验证.对比传统固定路径车辆调度方案,基于灵活路径的车辆调度方案使总疏散时间和平均乘客延误分别减少了 4.2%和 4.4%.结果表明,本文提出的模型能够提高公交应急桥接疏运效率、降低乘客延误.     

基于APT试验的半刚性基层沥青路面动力响应分析

通过足尺试验路加速加载试验研究半刚性基层沥青路面的动力响应,为路面性能预估及结构设计提供依据。通过修筑水泥稳定碎石基层和二灰稳定碎石基层2种结构APT试验路,埋设水平应变仪、竖向压应力传感器和温度传感器,实时采集路面结构动应力、应变、弯沉和路面温度场,分析温度与结构动应变、应力响应的关系,开展基于FWD弯沉盆的路面结构层模量和力学响应计算分析。研究结果表明,半刚性基层层底拉应变受温度影响较小,半刚性基层厚度对结构弯沉影响较大;半刚性基层厚度越小,其模量衰减越快;随重复荷载作用,半刚性基层层底拉应变响应先较快增加而后缓慢减小;在路面使用初期(2 560万次标准轴载),半刚性基层结构模量衰减较慢,当轮载作用1亿次标准轴载累计当量轴次时,半刚性基层模量约衰减55%。     

《机械工程材料与热加工基础》课程思政建设路径研究

课程是实施人才培养的载体,《机械工程材料与热加工基础》课程是机械类专业的专业基础课,对专业课的学习起支撑作用,开展该门课程的思政建设,对提高学生的学习兴趣、提高人才培养质量至关重要。本文从课程建设的思路、步骤和可能遇到的问题几个方面探讨了课程思政建设的路径,以期为其他课程建设提供支撑。     

车桥耦合模型研究

文章推导了简支梁桥在移动荷载、移动刚体和弹簧质量块三种简化车辆模型作用下的车辆-桥梁系统振动微分方程,编制了基于龙格-库塔法的车桥耦合分析程序,并结合算例比较分析了简支梁桥在三种不同车辆简化模型作用下的动力响应。     

Communicating transportation carbon dioxide emissions information: Does gender impact behavioral response?

General concern and knowledge on climate change have been increasingly studied over the past decades. Gender differences have been found for general environmental concern and knowledge, but mixed findings exist with respect to climate change. In transportation, research has examined potential relations between environmental attitudes and transportation behavior, with mixed findings as well. Recently, the use of carbon dioxide (CO₂) emissions information to influence choice has been tested with women being found more willing to pay to reduce their personal impacts, suggesting that women are either more willing to change or that their response to information on climate change is stronger. However, those studies used CO₂ mass and studies that examined understanding of CO₂ information as a mass have found that people struggle to understand it. If concern and knowledge about climate change differ amongst individuals, then, according to theories such as the Transtheoretical Model, the type of information used to motivate choices is likely important. Using a unique data set (n = 236) it is possible to take a first look at how gender might affect concern, knowledge, and action in terms of transportation and climate change. Further, it is also possible to examine behavioral responses to transportation climate change information. Finally, an empirical analysis is conducted of the effect of how the information is presented might differ by gender. Thus, this work aims to investigate whether gender differences might contribute to the explanation of individual behavioral responses (from concern to action) in a transportation climate change context.     

Guidance for new policy developments on railway noise and vibration

Noise and vibration are two of the main problems associated with railways in residential areas. To ensure quality of life and well-being of inhabitants living in the vicinity of railway paths, it is important to evaluate, understand, control and regulate railway noise and vibration. Much attention has been focused on the impact of noise from railway traffic but the consideration of railway-induced vibration has often been neglected. This paper aims to provide policy guidance based on results obtained from the analyses of relationships estimated from ordinal logit models between human response, railway noise exposure and railway vibration exposure. This was achieved using data from case studies comprised of face-to-face interviews (N = 931), internal vibration measurements (N = 755), and noise calculations (N = 688) collected within the study “Human Response to Vibration in Residential Environments” by the University of Salford, UK. Firstly, the implications of neglecting vibration in railway noise policies are investigated. The findings suggest that it is important to account for railway induced vibrations in future noise and transport policies, as neglecting vibrations results in an underestimation of people highly annoyed by noise. Secondly, implications of neglecting different types of railway sources are presented. It was found that the impact of noise and vibration form maintenance operations should be better understood and should be taken into account when assessing the environmental impact of railways in residential environments. Finally, factors that were found to influence railway vibration annoyance are presented and expressed as weightings. The data shows that factors specific to a particular residential area should also be taken into account in future vibration policies as the literature shows that attitudinal, socio-demographic and situational factors have a large influence on vibration annoyance responses. This work will be of interest to researchers and environmental health practitioners involved in the assessment of vibration complaints, as well as to policy makers, planners and consultants involved in the design of buildings and railways.     

提高铸管退火合格率的生产实践

退火炉结构复杂,自动化程度高,操作难度大,不易维护,铸管内在质量不稳定,退火合格率仅为94.5%.文中针对铸管退火合格率较低,铸管内在质量不稳定问题,从铸管常见的机械性能不合格、压痕不合格两个方面入手,通过炉前V型槽改造、炉内轨道结构改进、煤气管道上增设脱水过滤器等措施,解决了铸管常见的机械性能不合格、压痕不合格问题,...     

新型停放制动机械缓解装置设计研究

分析了目前城市轨道交通车辆停放制动械缓解装置的技术背景,以及存在的问题和安全隐患。详细介绍了新型停放制动机械缓解装置的组成、结构设计和功能原理。模型车试验验证和真车型式试验验证表明,其性能满足用户提出的在车上、车下均能操作机械缓解停放制动的需求。同时,新型停放制动机械缓解装置的操作受到车辆监控系统的监控,更加安全可靠。该新型停放制动机械缓解装置已经批量应用在出口美国波士顿的地铁车辆上。新型停放制动机械缓解装置的设计思想给我国城市轨道交通车辆设计和铁路动车组车辆设计提供了方向。     

漂浮式海洋能平台运动响应耦合预报研究

随着海洋工程向远海发展,漂浮式海洋能平台的运动响应预报问题成为研究的热点之一.本文以漂浮式海洋能平台为研究对象,首先基于间接时域法,建立浮式平台时域运动方程,然后基于悬链线理论和全矢量形式的三维集中质量法,建立系泊系统运动方程.在使用自行开发的计算程序对以上方程进行求解获得初值后,以系缆和浮式平台的受力和位移作为2个运动方程的交互输入与输出,建立浮式平台与系泊系统的全耦合计算方法.最后对简化的浮式海洋平台进行计算,分析载体平台的运动响应和系缆受力情况.本文可为解决相关工程问题提供参考和借鉴.