水下近场爆炸双层防护结构抗爆能力的数值模拟分析

同步考虑水下近场爆炸冲击波载荷与气泡射流载荷的作用,综合分析双层防护结构型式及尺度对其抗爆能力的影响,可为双层防护结构的抗爆设计提供直接技术支持。采用基于欧拉法的气泡动力学程序模拟气泡的近壁脉动过程,基于能量等效原则,将射流水柱对结构的冲击简化为等效的射流载荷,通过编制MSC.Dytran软件子程序,在冲击波数值模拟阶段后自动添加等效射流载荷,实现更接近实际情况的双层防护结构遭受水下近场爆炸过程的数值模拟。以内壳单位板厚变形能表征双层防护结构的抗爆能力强弱,通过改变结构型式与尺寸参数,对不同支撑结构板厚、内壳板厚和内外壳间距下结构的抗爆能力进行批量计算,以结构总重和抗爆能力为双重目标,借鉴多目标优化思想,得到双层结构抗爆能力的最优解集。计算结果表明: 当内外壳厚度及其间距一定时,存在最佳支撑结构板厚;在同等结构重量情况下,Y型双层结构能提供更强的抗爆能力。

     

基于仿真的沿海港口甩挂场站布局方案比选

甩挂运输以其高效低碳的特点正得到迅速发展。针对当前国内甩挂场站研究中功能布局、建设规模等方面的量化研究相对不足,利用微观仿真软件VISSIM建立沿海港口甩挂运输场站交通仿真模型,研究甩挂车辆在场站内运行状况,评价场站内部功能布局方案,并以某港口为例,验证该模型的有效性。     

基于最大熵谱估计的舰船静电场实时检测方法

舰船静电场是海水中舰船产生的物理场之一,是很难被隐身的目标特征信号.以往对静电场的检测方法都是基于信号的时域特征,低信噪比情况下,检测效果差.通过对舰船静电场的频域特征分析发现,其能量主要集中在低频段,利用这个特点,提出了一种基于最大熵谱估计(MESE)的舰船静电场实时检测的方法.首先对舰船静电场信号进行最大熵谱估计,然后提取低频段功率谱值作为特征量,通过设定的浮动阈值进行分段功率谱滑动检测,用实船数据对该方法进行了验证,取得了较好的效果.     

装配式码头灌浆连接节点压弯性能试验研究

对3组装配式码头灌浆连接节点试件进行压弯试验,研究不同灌浆长度和灌浆厚度下灌浆节点的压弯承载力、延性和破坏模式。结果表明,灌浆节点试件具有较好的延性和较高的承载力,灌浆节点受压弯荷载的破坏模式为钢管的压屈破坏;压弯构件的极限承载力随着灌浆长度的增大而增大;灌浆厚度的变化对构件的承载力影响不大,但灌浆厚度增大可以提高灌浆体底部的抗裂能力,建议实际应用时适当增大灌浆厚度。     

移动机械行走位置校正方法的改进

我国北方煤炭输出港的工艺布局及设备选型中常有多台移动机械共轨道运行的情况,为防止发生设备意外碰撞造成重大事故,各种装卸设备之间涉及到空间防碰撞保护的问题.     

多种移动键盘分析

移动键盘已广泛应用于移动和手持设备，介绍了目前几种常见的移动键盘，并对其进行分类，同时对其文本输入的速度和准确率做了简单分析。     

Port co-opetition in concept and practice

The port industry has undergone a rationalization process over the last decade. An increasing proportion of port management and operations is being taken over by global port operating groups. Many port operators who previously ran only their local business now extend their business scope to the regional or global scale; today's port operators can be regarded as multinational corporations. In the era of global economy, a port no longer enjoys a natural monopoly, as was the case in the past. To cope with this changing business environment, a certain form of competition and co-operation among ports is necessary so as to provide services that fit into shipping lines' strategies. It is suggested that ports have to concentrate on new ways for co-operation in an effort to establish a countervailing power. This paper proposes a new strategic option known as co-opetition, the combination of competition and co-operation, for the port industry, and explains a case of co-opetition between the container ports in Hong Kong and South China. The results of this research will provide a useful insight into the port industry, which is currently required to carry out its business in an ever-changing business environment.     

Maritime logistics as an emerging discipline

The evolution of maritime logistics as an emerging discipline has resulted, to a large extent, from the increasing and varied demands of shippers and customers and the rapidly changing role of ports in the context of supply and logistics chains. Scholars are becoming increasingly aware of the need to integrate logistics and supply chain management concepts in the maritime transportation chain and operations. This article aims to provide a review and foundation for understanding the domain of maritime logistics and to assess its potential as an emerging discipline. To do so, a framework for understanding the various aspects of maritime logistics strategy and implementation is developed. A synthesis of the existing knowledge on maritime logistics is done by integrating diverse explorations forming the basis of this framework. We draw upon the literature on maritime transport and ports and primarily theliterature that analyses concepts by adopting an economic or management perspective.     

紧抓历史机遇夯实发展基础为实现中铁物资战略目标开好头起好步

1 在复杂多变的经济环境中顽强拼搏,2008年各项工作取得了新的成绩 1.1 生产经营继续较快发展,取得了良好业绩 全年实现营业收入1002亿元,历史性地迈上了千亿元的大台阶,比上年增长26.8%.完成了国资委经营业绩考核指标.     

上海西藏南路南段改拓建工程方案概述

结合上海西藏南路南段（复兴东路一中山南路）改拓建工程,介绍了在规划红线宽度受限、周边建设条件受制约的情况下,对该路段建设规模的论证及平面线形优化的方法,并对拓建方案进行了比选。