小安溪大桥箱梁悬浇施工控制

介绍小安溪特大桥悬浇箱梁施工控制的分析原理,实施方案及主要内容。     

浅谈对MARPOL73/78公约2004修正案的理解和针对性PSC检查

本文对MARPOL73/78公约2004修正案进行了概述,重点阐述了在港口国监督检查过程中需注意的问题及重点检查的内容。     

An ERP approach for container terminal operating systems

The major characteristics of ERP (Enterprise Resource Planning) are an enterprise-wide system that covers all the business functions and information resources, integrated database, built-in best industry practice, packaged software and open architecture. ERP enables reduction of system development time, flexibility, standardization of workflow and effective business planning capability. ERP is mainly for the manufacturing industry. However, the principles of ERP can also be applied to container terminal operating systems. This paper presents an ERP system approach for a container terminal. It has clustered the workflow of a container terminal and analysed the business process to generate the best workflows. The integrated database is designed to eliminate redundancy and keep integration. The core of ERP for container terminal is the planning facility such as berth planning and yard planning. The planning capability is very tightly coupled with data flow from client entities such as shipping companies. The ERP can handle the existing problems of container terminal operation that are mainly caused by lack of integration of a whole information resource in a container terminal, ad-hoc and poor planning capability, disconnected and incorrect data from client companies. The ERP approach can not only resolve the problems of container terminals but also promote adoption of information systems for container terminals in the world that have not yet implemented terminal operating systems.     

多式联运讲座（2）—第二讲 承运人的责任

1承运人责任体系的渊源国际货物运输中,各国的相关法规,多数是通过本国立法程序使相关的国际公约在本国生效而适用的。尽管如此,在多式联运中还没有已生效的国际公约可供使用,而已经生效的各种运输方式所适用法规的责任体系又不尽相同。在这种情况下,对不同法系的货物运输合同的责任基础有所了解,对合理地订立多式联运合同,相信是会有所裨益的。     

船用捷联惯导系统在系泊状态下的快速初始对准方法

建立了捷联惯导系统的误差模型，并利用ＰＷＣＳ理论对系统模型进行了可观测性分析。在可观测性分析的基础上提出了一种估计方位失准角ψＵ的方法，从而大大缩短了系泊状态下初始对准时间，提高了对准速度。最后，通过计算机仿真证明了该方法的有效性。     

全电子道岔模块的设计

在铁路信号控制领域，目前应用最广的是6502电气集中和以继电器为执行机构的计算机联锁系统。应用全电子模块设计的计算机联锁系统虽起步较晚，但一定是未来计算机联锁系统的发展方向。本文介绍的全电子道岔控制单元，采用了四线制道岔控制电路，其结构框图如图1所示。     

物流小辞典

物流延迟(Logistics Delay) 又称“时间延迟”.是以时间为基础的物流概念之一.是指将商品先储存在某个或某若干个战略库存点,以保持大生产的规模经济效益,在收到客户订单后,再立即将商品快速发运给客户,例如将关健的和高价的零部件储存在中央仓库内,以确保所有的潜在用户的使用.     

车侧窗多功能贴膜循环升降系统设计

目前,汽车贴膜就是在车辆前后风挡玻璃、侧窗玻璃以及天窗上贴上一层薄膜状物体,主要作用是阻挡紫外线、阻隔部分热量以及防止玻璃突然爆裂导致伤人等情况发生,同时根据太阳膜的单向透视性能,达到保护个人隐私的目的。但是这种贴膜只能一次性使用,而且为了应对汽车在行驶过程中遇到的各种状况,人们就会相应地对车窗有各种不同的需求。目前一次性车窗贴膜并没有很好地满足人们对车窗各种不同的需求。文中设计一种简单的汽车贴膜升降切换系统,可以根据人们的不同需求,随时随地切换不同功能的贴膜。     

Influence of fastener stiffness mutation in ballastless track on dynamic characteristics of high-speed trainsEI北大核心

Research purposes: The elasticity for the ballastless track structure is mainly provided by the fastening system. During the construction and maintenance of ballastless track on high-speed railway, the incorrect installation and the unreasonable transition between the old and new rail-pads may occur to the fasteners, which will cause a stiffness mutation for the fasteners. Even though this problem can hardly be found under the static condition, it can have a great effect on the stability and safety for the high-speed vehicle operation. Here different conditions for the fastener stiffness mutation are considered, according to the actually measured data. And the influence of fastener stiffness mutation on the dynamic performance of high-speed vehicle and track is calculated and analyzed by using the vertically coupled vehicle-ballastless track-subgrade vibration spatial model and the finite element software ANSYS/LS-DYNA. Research conclusions: The calculation and analysis results show that: (1) When there is a local mutation for the stiffness of fasteners, the maximum and minimum of vehicle acceleration basically keep the same. That is to say, the fastener stiffness mutation has few influence on the stability of vehicle operation. (2) The fastener stiffness mutation has much obvious effect on the wheel load reduction rate, which is related to the safety of vehicle operation. Further, when the train speed is larger than 300 km/h, the fastener stiffness mutation will directly cause the wheel load reduction rate to exceed the standard. (3) This research results can be used to provide a theoretical basis for monitoring the fastener stiffness in construction or repairing and establishing the strict control standards in high-speed railway.     

一种蓄电池充放电电路的设计

应用电容滤波稳压电路原理设计蓄电池充放电主电路,再应用继电器开关原理设计出控制电路,实现不同充电电压的选择。为了加强蓄电池充放电电路的安全性能,设计出一种限压、限流的保护电路。根据蓄电池充放电的基本原理、特性、方法等,设计出一种简易、实用的充放电电路,具有良好的可逆性和稳定性。