双闭环全数字控制的旋转装置

根据研制船用新型计程仪和传感器等设备的需求,设计了双闭环全数字控制的旋转装置.该装置作为试验设备的载体,它与试验水池配套,为船用新型仪器进行动态性能测试提供试验平台.旋转机构由直流电动机拖动,在工控机的控制下,载着试验设备在水池中作旋转运动.为了实现对旋转臂转速的自动控制和实时监控,设计了双闭环全数字V-M调速系统.试验结果证明,旋转装置设计新颖,转速控制精度高,且操作方便可靠.     

东江下游航道整治工程数学模型研究方法

通过边界贴体坐标方法将受枢纽和人工挖沙等影响剧烈的东江下游水道水沙变化规律进行数学模拟,解决了方案比选和优化的问题,并对回淤或冲刷情况进行了预测,为初步设计提供依据。     

18 000 t化学品及成品油船设计和TC规则

18 000 t化学品及成品油船是江南造船集团为加拿大Algoma Control corporation公司建造的.入DNV船级社.挂加拿大旗.该文主要介绍了18 000 t化学品及成品油船的主要技术特点(主要技术参数、结构特点、舾装特点、防腐蚀、轮机特点、化学品和成品油船专用系统、电气特点、安全保障)和挂旗国加拿大TC规则(送审工作、要TC证书的材料和设备、有TC型式认可证书的国内产品、TC规则特殊要求、圣劳伦斯运河要求).     

Regulatory reform and freight mode choice

Reform of trucking Vehicle Weights and Dimensions (VWD) regulations in Canada is now underway. The effect these reforms will have on the freight transportation industry are only recently the subject of research. This paper is part of this new research effort, aimed at understanding how regulatory reform in the trucking sector will affect the existing competitive relationship between trucks and the railways. The paper presents the results of study and research into modelling the relationship between mode choice and the service characteristics that are affected by VWD reform.Using several periods of data, a series of econometric models are developed which help to elucidate the relative relationships between the mode service characteristics for both of the principal interprovincial freight modes. A technique is developed and presented to model railway user costs in order to overcome the complex and often unrepresentable pricing activities of Canadian railways.The strength of the developed econometric models is presented, including their significance and statistical reliability. This is further reinforced by the similarities exhibited by all the models in the series. The selected model is applied to predict market service responses required of the railway industry in order to compete with the trucking sector now adapting to the new regulations.The impact of the newly implemented vehicle weight and dimension reform on the rail transportation industry is analyzed and railway industry improvements aimed at maintaining its market share are presented. The results predicted by the model show that railway user cost reductions should be moderate, and likely less than the level of inflation over the period of time when trucking converts its fleet to take advantage of the new regulations.Abbreviations AASHTO American Association of State Highway and Transportation Officials - CCMTA Canadian Conference of Motor Transport Administrators - EPI End products, inedible commodity classification - GVW Gross Vehicle Weight - NA 1988 VWD National Agreement - RTAC Roads and Transportation Association of Canada - VWD Vehicle Weight(s) and Dimension(s) - WA 1988 VWD Western Agreement     

基于TDM的出租车供需调控方案研究

交通需求管理（TDM）是能从根本上解决城市交通问题的策略,具有现实的意义。针对成都市出租车供需现状,运用系统的思想对各供需调控方案进行评价比选,分析交通需求管理的必要性并提出针对出租车的交通需求管理的具体措施,可为解决出租车的供需矛盾提供参考。     

闽江水口枢纽坝下水位降落整治方法研究

枢纽下游河床遭受清水冲刷,河床下切、水位降落是普遍的规律,也是历来枢纽设计及航道整治中的重点和难点,文中针对闽江水口枢纽坝下水位降落幅度及河床地质条件,采用1:100正态物理模型与遥控自航船模相结合的研究手段,提出了若坝下水位降落幅度较小,且坝下河床冲刷已基本稳定,可采取潜坝或明渠及溢流坝方案治理;若坝下水位降落幅度较大,且坝下河床冲刷仍在继续,单纯解决通航问题可采取船闸改造或船闸加中间渠道方案治理。     

船用伙食冷库自控系统的改造设计

文章针对早期船用伙食冷库以继电器为主导的控制系统所存在的问题,以某一滚装客船冷库为例,根据该冷库的运行技术特点,开发出以西门子s7系列可编程控制器为核心的自动控制系统,满足了冷库运行过程的精确掌控、节约耗能和可靠性等要求。     

也论柴油轿车在国内市场的发展前景

研究了世界范围内柴油机在乘用车领域内的应用现状,阐述了柴油机作为车用动力的优势。根据国内的政策环境与市场环境,分析了排放法规、柴油品质对市场的影响。根据对柴油轿车的性能要求,包括振动和噪声、排放等,分析了更适合我国轿车柴油机发展的技术路线,并重点对若干关键技术和难点进行了剖析。柴油机技术进步和市场化应用表明,柴油轿车在我国具有广阔的应用前景,政府和企业应做好政策和技术上的准备。     

大比降卵砾石河流防护结构的冲刷深度研究

大比降卵砾石河流河床形态及水流条件特殊,治理难度相当大。当遇到较大的洪水时,堤防工程、公路等临河设施常发生水毁,而关于此类河流的研究成果较少。针对大比降卵砾石河流河床宽浅、滩槽不分、比降和流速大、枯水期水流分散易形成股流冲刷的特点,布置了不同床沙组成、冲刷角度、河床比降及流量的概化模型试验。通过对81组室内试验资料进行单因素分析,得知冲刷深度(Hp)与单宽流量(q)、河道比降(J)、冲刷角度(θ)成正比,与河床质颗粒组成(D)成反比。采用量纲分析法和多元回归分析法得到了冲刷深度的计算表达式。     

加快制定汽车行业CAE分析流程及结果评价体系--促进我国汽车行业CAE软件应用水平

我国汽车产业经过几十年的发展,取得了很大进步,然而与国际先进的设计、制造技术相比还有很大的差距,特别是仵CAE技术应用和结果评价体系方面存在巨大差距,因此尽快制定汽车行业CAE分析流程和结果评价体系,加强相关汽车安全标准的制订、强制性检测项目的实施,以促进汽车设计分析技术的进步,提高汽车安全性能,比如我国汽车正面碰撞安全性法规的实施．就极大地推动国内汽车企业CAE仿真分析的开展和软件应用水平的提高,进而也促进了产品可靠性的提高和产品研发实力的提升,为我国汽车企业参与国际竞争提供了技术保证。