汽车甩挂运输最佳运距的研究

汽车甩挂运输是先进的公路运输形式之一。从汽车甩挂运输生产工艺的全过程和昼提高车时利用率出发，提出了适合我国目前推行汽车甩挂运输的最佳单程运距为５３－１００ｋｍ、１３３－２２０ｋｍ和２９３－４６０ｋｍ。     

Parallelization of a Two-Phase Metaheuristic for Routing Problems with Time Windows

This paper describes the parallelization of a two-phase metaheuristic for the vehicle routing problem with time windows and a central depot (VRPTW). The underlying objective function combines the minimization of the number of vehicles in the first search phase of the metaheuristic with the minimization of the total travel distance in the second search phase. The parallelization of the metaheuristic follows a type 3 parallelization strategy (cf. Crainic and Toulouse (2001). In F. Glover and G. Kochenberger (eds.). State-of-the-Art Handbook in Metaheuristics. Norwell, MA: Kluwer Academic Publishers), i.e. several concurrent searches of the solution space are carried out with a differently configured metaheuristic. The concurrently executed processes cooperate through the exchange of solutions. The parallelized two-phase metaheuristic was subjected to a comparative test on the basis of 358 problems from the literature with sizes varying from 100 to 1000 customers. The derived results seem to justify the proposed parallelization concept.     

轮腿结合步态稳定裕度的研究

研究一种轮腿结合式步行机的步态特性和静态稳定裕度与步态参数间的关系，并对这类步态进行了计算机仿真。     

Steady light diffusion application to rheology: a new tool for the characterization of concentrated suspensions

We present new developments of steady light diffusion applied to rheology. Though many techniques allow the structural investigation of diluted or transparent media, very few give direct information on optically dense systems. The technique proposed here is based on the diffusion approximation and is thus valid for sheared, time-dependent flows.After recalling important theoretical results, we show the techniques ability to determine typical sizes and orientation of structures in shear flows for various concentrated suspensions (emulsions, and an industrial softener). In particular, it is able to demonstrate the effect of shear on the orientation of anisotropic objects. Moreover, the use of simple structural models incorporating the measured anisotropy allows good predictions of experimental rheological measurements. This new technique, applicable to a wide range of colloidal systems, is very helpful to characterize the shear induced structural organization of optically dense materials.This paper was presented at the first Annual European Rheology Conference (AERC) held in Guimarães, Portugal, September 11-13, 2003.     

车速对汽车瞬态响应的影响

介绍了在前轮角阶跃输入下线性二自由度汽车模型的瞬态响应,讨论了行驶车速对汽车瞬态响应的影响。实例计算表明,较低的行驶速度使汽车具有较好的瞬态响应特性。     

基于HSV空间的车牌定位方法

车牌区域的颜色特征是车牌的重要信息.针对车牌区域颜色的伴生与互补特性,提出了一套在HSV空间利用颜色特征进行定位的算法.该算法利用车牌区域固定的颜色特征,快速定位到与车牌颜色有关的区域,然后利用车牌区域伴生与互补特性快速去除具有与车牌区域相同颜色的其他非车牌区域.最后使用投影积分进行车牌的精确定位.通过对200幅从交通卡口获取的真实的彩色图像进行试验,准确定位率为98%.     

重庆市机动车尾气污染现状及控制对策

在对重庆市主城区机动车保有量进行深入调查的基础上,就机动车尾气排放对大气环境的影响进行了分析和评估,并对汽车尾气排放污染物NO2进行了纵向和横向的对比;阐述了机动车尾气是造成重庆市城市大气污染的重要因素。同时,借鉴国内外先进的预防、控制和处理机动车尾气污染的方法,对机动车尾气排放污染控制措施进行了研究,提出了合理减缓、控制机动车尾气污染等措施。     

车辆荷载谱作用下简支T梁力学性能

由自编程序VLS(vehicle load spectrum--车辆荷载谱)构造随机车辆荷载谱,利用有限元程序将一般运行状态下的随机车辆荷载谱加载于简支T型钢筋混凝土梁上,模拟该梁在车辆荷载通过时的动力响应,得到了T梁位移时间历程曲线以及梁压区混凝土和拉区钢筋的应力时间历程曲线,并分析了压区混凝土和拉区钢筋的疲劳性能.结果表明车辆荷载谱作用下T梁动挠度大于汽车-20和挂车-100静荷载作用下的挠度;压区混凝土及拉区钢筋的最大应力均介于汽车-20和挂车-100静荷载作用下的应力值之间;T梁疲劳寿命可达到2×106,但不超过2×107;拉区钢筋不能够满足混凝土规范关于疲劳验算的规定,需要进行验算.     

简论机车车辆的可靠性与维修性及维修信息管理

论述了机车车辆"以可靠性为中心的维修"理论中的可靠性和维修性的定义、评价指标和设计方法,讨论了两者之间的关系;并对维修信息管理作了分析,说明了在高速、重载铁路迅速发展的今天,优良的维修管理信息系统对越来越复杂的机车车辆维修具有重要意义.     

210国道对牛背梁保护区羚牛东西扩散影响的研究(Ⅱ)——210国道车流量变化规律

2000年10月—2001年10月,采用定点观测的方法,对210国道保护区段每日04:00—22:00时的流动车辆进行了观测,总计流动车辆65 755辆,按观测日数计算,日均车流量782.8辆,平均1.37辆/2 min.每日15:00时的车流量最大,06:00时的车流量最少;主要集中在09:00—22: 00时,而以14:00—18:00时最为集中;每日的车流量变化可以分为四个阶段:即04:00—07:00时、07:00—13:00时、13:00—19:00时和19:00—22:00时,其中13:00—19:00时最大,19:00—22:00时次之,04:00—07:00时最小.