开孔金属腔体场强增强效应分析

为分析开孔金属腔体的场强增强效应,以正方形金属腔体为受试对象,基于数值计算软件CST建立开孔金属腔体场强增强效应计算模型,分析开孔形状、开孔尺寸、入射波极化方向等不同参数对孔缝中心及腔体中心场强增强效应的作用规律。提出使用GTEM小室进行开孔腔体电磁耦合测试新方法,搭建实验平台,验证数值计算结果的正确性,阐释场强增强效应耦合机理。结果表明:当面积相同时,和正方形、圆形孔缝相比,长方形孔缝的场强增强效应显著,长方形孔缝的长宽比越高,场强增强效应便越大;长方形孔缝的增强效应与垂直于孔缝长边的电场分量呈正比;腔体壁厚是影响场强增强效应的关键因素之一;在孔缝中心沿中轴线附近,时域场强峰值呈指数衰减;孔缝中心和腔体中心的场强增强效应耦合机理不相同。     

城市街道重塑——激发步行化公共生活

伴随着城市机动交通的快速增长,步行活动在街道上受到排挤。基于对城市街道公共生活视角的研究,阐述了街道对城市步行化公共生活具有重要意义,而城市中机动交通对街道的主宰、建筑与街道的疏离等问题导致了街道步行化公共生活的凋敝。面对现状,街道对公共生活的意义在理论与实践层面被重新认识与探索。最后提出了以激发步行化公共生活为导向的城市街道重塑方法。     

海底溢油输移扩散的可视化数值模拟系统

为直观研究溢油在复杂水下环境中的动态行为,设计和开发一套海底溢油可视化数值模拟系统(SIMPACT-SOS).系统由数值模型、数据库和图形界面构成,具有地理信息系统(GIS)应用平台、数值建模分析、溢油数值模拟等专业功能.应用算例表明,SIMPACT-SOS系统可为海底沉船溢油、海底输油管道泄漏、海洋石油钻井井喷等水下污染事故的风险评估、应急决策及损害评估提供理论和技术支持.     

Timed quenching process for large-scale AISI 4140 steel shaft

The mechanical properties of AISI 4140 steel shaft with a diameter larger than 200 mm are difficult to meet the requirements and cracking occurs easily in water quenching, due to insufficient cooling ability of oil quenching. A new technology, named alternately timed quenching (ATQ), using water and air in turn as quenching media instead of oil or polymer aqueous solution, is applied to quench the large-scale AISI 4140 steel shaft. Two ATQ processes are determined with the aid of computer simulation first and the corresponding experiments are carried out consequently. The results show that the proposed technology can significantly reduce the surface cracking tendency and improve the mechanical properties in practical production of such large-scale shaft forgings.     

ROV在导管架检查中的应用与安全管理

海上石油平台安装后,需要定期对导管架水下检查,以确保人员和生命财产安全。ROV遥控潜水器类似于一种＂带缆的水下机器人＂。在超过空气潜水范围的水深处检查具有明显的安全、效率、成本优势。介绍了ROV的功能和优势,介绍了固定式平台之钢质导管架式平台特点。以某导管架为案例,详细介绍了ROV的操作步骤。并介绍了ROV作业中的风险...     

高职院校汽车检测与维修技术专业建设标准思考

专业建设标准是专业教学和专业建设的重要指导性依据,对于专业人才培养质量和服务区域经济发展具有重要的意义。文章调研分析了汽车检测与维修技术专业定位和人才培养方案,对课程体系和教学学时安排建设、师资队伍建设、实践教学建设、校企合作和国际交流建设等情况进行了分析。提出了汽车检测与维修技术专业建设标准的建议。可为省内其它院校汽车检测与维修技术专业建设提供参考。     

三维GIS数字矿山剖切算法研究

本文将GIS和BIM技术相结合,并利用可视化技术以图形图像方式逼真的再现三维地质实体等地学信息,实现了对地质实体的任意剖切.本文简要介绍了3DGIS关键技术,详细介绍了对空间对象的剖切技术.将三维实体的任意剖切技术和BIM技术相结合实现了对地质体内部属性的快速获取,使得既不影响系统显示又保证了系统的实时性.使得矿山各级生产管理部门直观、快速、精确、全面地了解矿山生产状况和储量信息.为矿山生产管理人员实施调度指挥、矿山开采等工作提供优良的决策依据.     

Route Selection for Railway Passengers: A Multi-objective Model and Optimization Algorithm

With an increased operating speed in Chinese railways in recent years, the number of passengers traveling by trains has been significantly increasing. The research issue is regarding how passengers select their routes when there are no direct trains. Previous studies have dealt with the route selection problem as a multi-objective optimization. The study began by setting up a transportation network which encompasses the departure and terminal stations along with important intermediate stations. Then, six key factors are analyzed and formulated using a multi-objective model, consisting of the train-running time, railway fare, transfer frequencies, distances between transfer stations, transfer interval time, and travel comfort. Furthermore, a two-phase algorithm is employed to solve the model. A rapid searching algorithm for feasible routes based on the train timetable is established, then the weight vector is assigned by introducing the information entropy to obtain satisfied routes. In the end, the two-phase algorithm is tested respectively for railway passengers from Lanzhou to Beijing (with direct trains) and from Lanzhou to Changchun (without direct trains), and the results show that the proposed model and solution algorithm are efficient for obtaining satisfactory routes.     

基于大数据的新能源汽车个性化售后服务推荐系统

国内新能源汽车售后服务市场起步较晚,用户满意率不高,服务体系亟待完善,在大数据的时代背景下,跳脱出固有的被动服务的思维模式,借助信息化的强大力量刻画用户画像,构建符合时代发展和用户个性化需求的主动推荐售后服务系统,由"用户主动预约"向"主动预约用户"转变,扭转我国新能源汽车售后服务市场态势,将成为我国新能源汽车售后服务发展的一大趋势。     

非晶合金变压器在城市轨道交通中的应用分析

通过对非晶合金变压器特点的分析,研究了城市轨道交通动力照明负荷特性,结合非晶合金变压器作为配电变压器在城市轨道交通中的实际挂网应用情况,验证了非晶合金变压器的空载损耗优越性能特别适合城市轨道交通配电变压器负荷率较低的特点,同时还对城市轨道交通牵引负荷进行了简单分析,指出非晶合金变压器作为整流变压器应用也有节能的前景。