长江三角洲港口群竞合策略之我见

港口群是指一些地理位置相近、共有部分腹地,部分功能可以互相取代并且互为竞争对手的港口组成的群体。长江三角洲港口群由上海、江苏、浙江两省一市的港口组成,包括上海港、宁波-舟山港、连云港、张家港等十几个重要港口。江浙沪位于我国东部沿海地区的沿江产业密集带,江海交汇,具有得天独厚的区位条件,是我国经济最发达、最具活力和竞争力的区域之一,在此区域内的长三角港口群是我国沿海港口群中港口分布最密集、吞吐量最大的港口群。     

某型电机调速系统控制回路设计

根据装备正常工作对输入控制信号的要求,设计了该型装备电机调速系统控制回路。该控制回路采用单片机和FPGA协同工作,用数字方式实现SPWM信号。经过实际应用,该方法产生的电机调速系统控制信号不仅精度高,调节方便,而且系统非常稳定,适宜于大多数野外场所使用。     

China shipbuilding management challenges in the 1980s

Since the economic reforms in the late 1970s, the shipbuilding industry in China has enjoyed rapid growth. Over the past two decades, many new building contracts have been won and successfully completed. However, some shipyards have also suffered great losses. Basing on their experience in Southern China, the authors examine some of the major challenges that Chinese shipbuilders faced during this transitional period, when the industry ventured into the international market. These challenges are broadly categorized into two areas: (i) external factors, such as inflation and infrastructural support that the shipbuilder had no control over, and (ii) shipbuilding management, which the shipbuilder had to master in order to gain competitive advantage. Suggestions on how these problems could be tackled are discussed.     

50 000 DWT散货船结构设计的点滴体会

本文介绍了作者在５０ ０００ ＤＷＴ散货船的设计过程中,关于底部纵桁布置、抓斗加强、卷筒钢板加强、进水强度以及结构工艺等几方面的一些体会。     

武隆乌江特大桥缆索吊的优化设计与施工

在利用MADIA和SAP2000软件对扣锚索、工作索、缆风和塔架进行强度和稳定性结构分析计算的基础上,结合施工经验对武隆羊角乌江大桥钢筋砼顸制箱形拱桥缆索吊进行了双肋合龙改单肋合龙的优化设计,并阐述了施工中的关键技术和质量控制措施,总结并提高了大跨度缆索吊装设计和施工工艺。本缆索吊的优化设计不仅成功地保证了施工安全,而且创造了良好的经济效益和社会效益,这对类似桥梁的吊装设计与施工有一定借鉴和指导意义。     

地铁地下车站土建工程委托监理合同风险分析与防范

建设工程委托监理合同是建设工程主要合同之一.在工程实践中,监理往往重视对施工承包合同的管理,但忽视了对关系到自己切身利益的委托监理合同的管理,造成了土建工程委托监理合同履行的高风险.正确地认识地下车站土建工程委托监理合同所面临的风险,探索合同风险防范对策,对确保委托监理合同全面履行具有重要意义.     

悬挂式止水帷幕止水作用的数值分析

通过对三维非稳定流问题的理论分析,建立三维渗流的有限差分模型,使用地下水渗流软件VisualMODFLOW,并以西安地铁—号线通化门车站深基坑降水工程为例进行计算.将有无悬挂式帷幕两种工况的水头降深计算结果与实际存在悬挂式止水帷幕的实测值进行对比,定量说明悬挂式止水帷幕对基坑降水的影响.     

基于DirectS how技术船用钢板图像采集设计与实现

基于DirectShow技术,在Windows平台下构建测量船用钢板三维尺寸的图像采集系统,为大尺寸物件的测量提供了一种信息采集方案。首先分析了DirectShow技术基本体系,接着介绍了该系统的应用环境整体布局以及采集系统总体设计方案,其次通过对常见的视频采集卡进行分析,给出了针对USB摄像头,基于MFC框架的图像采集系统实现过程,包括设备Filter的构建,Filter Graph结构设计,开发了本系统所用到的抓图Filter,实现对应用环境画面的实时监控和采集,通过实验表明设计方案的可行性和正确性。     

船用曳引式升降机动力学建模及仿真分析

对船用升降机动态特性的研究一直以来都是升降机研究领域的一个薄弱环节。针对船用升降机的特殊性,根据曳引式升降机的物理模型建立升降机垂直方向上的动力学模型,并结合模态分析法研究该模型,得出升降机位置对其固有频率的影响。以船体振动中螺旋桨和主机振动频率为激励频率,将理想电气速度曲线引入系统中,运用Matlab软件模拟系统响应的全过程,得出船用升降机的一些基本运行特性。     

Seabed scene simulation and its realization in extending Vega

Realistic simulation of underwater scene is always difficult because of the special and complex vision effects in underwater space. Seabed is an important part of underwater environment. This paper describes the methods for seabed scene simulation based on OpenGL. It includes construction of fluetuant terrain based on the random sinusoidal algorithm, simulation of seabed flicker effect by means of circular texture mapping and generation of turbidity effect by using fog techniques. For the application based on the leading high level 3D development environment-Vega, underwater scene simulation is still a difficulty since there is no module for it. Based on the analysis of Vega software and the research on seabed scene simulation methods, a Vega extending module named “Underwater Space” was created through developing module class and extending lynx interface. The module class was designed through developing DLL written in C . The Lynx was extended through developing keyword configure file, GUI configure file and lynx plug-in DLL. The problem that Vega can‘t simulate underwater space, is elementarily resolved. The results show that this module is efficient, easy using, and the seabed scene images am vivid.