考虑冲压引起板厚变化的油底壳模态分析

针对油底壳冲压过程中板厚会发生变化的现象,采用显式有限元法模拟油底壳整个冲压成形过程,获得油底壳板厚变化信息,将板厚信息映射到隐式模型中进行模态分析。通过与不考虑板厚变化模态结果和实验模态对比发现,考虑冲压过程引起的板厚变化分析结果与实验结果相比,其误差在5%以内,比不考虑板厚变化的分析结果各阶固有频率误差平均减小50%左右。     

汽车节能的因素与措施分析

随着汽车保有量的增加,我国面临更加严重的能源和环境问题,这些已成为制约我国汽车工业可持续发展的重要因素,人们越来越重视汽车的节能。本文主要从“人,车,路”三方面来分析影响汽车节能的因素,并且根据这些因素,从车的结构方面以及油品和驾驶人等方面提出了一些节能的措施,希望能够起到积极作用。     

基于灵敏度分析的发动机悬置系统稳健优化设计

以发动机悬置系统能量解耦为目标,悬置刚度参数为设计变量,考虑目标函数和约束函数对于悬置刚度参数的灵敏度,构造了多目标优化数学模型.采用遗传优化算法对一款发动机悬置系统的悬置刚度参数进行了稳健优化设计,并用Monte Carlo方法进行了分析.结果表明,优化方法可以有效降低系统解耦度对悬置刚度参数的灵敏度,提高了悬置系统设计的实用性.     

Data-driven ferry network design with candidate service arcs: the case of Zhuhai Islands in China

ABSTRACT

We investigate a ferry network design problem with candidate service arcs (FNDP-SA), which is a new variant motivated by areal-world case from Zhuhai Islands. In this research, the design of a ferry schedule must conform to strict constraints including technical feasibility, safety issues, environmental impacts and moreover, avoid conflicting with ferries from neighboring cities (i.e. HongKong, Shenzhen and Macao). Therefore, a set of cautiously approved service arcs are firstly given, based on which the ferry service network is optimized. This study is among the first to formally describe the FNDP-SA and model it as an integer program. A hybrid variable neighborhood descent (VND)-based algorithm is developed. Two sets of instances are generated based on the case of Zhuhai Islands, where the first set is based on historical ticket sales data while the second set is derived by incorporating increased demands in the future according to a questionnaire survey. Numerical studies have shown that 59% cost reduction on the first set can be achieved by the proposed VND algorithm when compared with manual results. Research outcomes of this study have been adopted and implemented to facilitate the sustainable development of the ferry service of Zhuhai Islands.     

高速铁路智能交通系统中的CBTC技术

介绍了国外基于通信的列车控制(CBTC)系统的概况,在分析我国铁路无线通信发展现状和铁路智能交通系统(RITS)的体系结构的基础上,阐述了CBTC的原理及高速列车定位、列车动态运行间隔控制等关键技术.     

A study on adjustment factors for U-turns in left-turn lanes at signalized intersections

U-turns are treated as left-turns in the current procedures for estimating saturation flow rates at signalized intersections. While U-turning vehicles are usually mixed with left-turning vehicles in inside or left-turn lanes and conflict with opposing through traffic as left-turning vehicles, the vehicle operating characteristics are different. The objective of this paper is to investigate the effects of U-turns on the traffic flow in left-turn lanes. Field data of 600 headways of left-turning passenger cars and 160 headways of U-turning passenger cars are recorded. The average headways of U-turning passenger cars are found to be significantly larger than those of left-turning passenger cars. The effects of U-turning vehicles depend upon the percent of U-turning vehicles in the left-turn lane, as well as the order of formation in the traffic stream. Adjustment factors for varying percents of U-turning vehicles in left-turn lanes are established.     

工程项目概预算审查工作浅谈

结合作者多年的工作实践经验，在分析基本建设工程概预算审查工作的意义，特点的基础上，对如何做好工程概预算审查工作提出了自己的认识。     

铁路局计量工作面对"十一五"的思考

随着铁路跨越式发展和路局改革的不断深入,计量工作迎来了前所未有的机遇和挑战。作者从我局计量工作面临的形式和存在的问题入手,就计量工作如何适应铁路运输安全生产,实现路局又快又好的发展目标,提出了自己的见解。     

邻硝基氯苯废液资源化技术研究

针对邻氨基苯甲醚车间排出的邻硝基氯苯甲氧基化母液废水,开发酸析-精馏技术,能有效回收含邻硝基苯酚不少于99％的产品,可广泛应用于有机合成和分析试剂中。同时,大大降低了该废液的COD值,为其最终经生物矿化处理奠定了基础。     

无线局域网最佳安全性方案

作为传统局域网的补充和扩展，无线局域网得到了迅猛的发展，但是安全性问题日益突出。通过运用现有的安全机制和无线设备，实现一个安全性较高的无线局域网的设计，得出最佳安全性设计方案。