100 m定尺钢轨基地焊接500 m长钢轨施工技术

京津城际铁路设计采用100 m定尺钢轨基地焊接成500 m长钢轨,再用500 m长钢轨一次性铺设、焊接、锁定成跨区间无缝线路,引进Gaas80/580闪光接触焊轨机及配套的除锈、四向调直、精磨等成套设备,对100 m定尺钢轨焊接500 m长钢轨的焊轨生产线布局、焊轨流程及工序、质量控制要点等进行介绍.     

Design optimization of a torpedo shell structure

An optimized methodology to design a more robust torpedo shell is proposed. The method has taken into account reliability requirements and controllable and uncontrollable factors such as geometry, load, material properties, manufacturing processes, installation, etc. as well as human and environmental factors. The result is a more realistic shell design. Our reliability optimization design model was developed based on sensitivity analysis. Details of the design model are given in this paper. An example of a torpedo shell design based on this model is given and demonstrates that the method produces designs that are more effective and reliable than traditional torpedo shell designs. This method can be used for other torpedo system designs.     

Sensitivity analysis of the probabilistic damage stability regulations for RoPax vessels

In the light of the newly developed harmonised probabilistic damage stability regulations, set to come into force in 2009, this article presents a systematic and thorough analysis of the sensitivity of the Attained Subdivision Index with reference to a wide range of related design parameters. The sensitivity of the probabilistic regulations was investigated for a typical large RoPax vessel, with variation of parameters, such as the number, positioning and local optimisation of transverse bulkheads; the presence and position of longitudinal bulkheads below the main vehicle deck; the presence of side casings; and the height of the main deck and double bottom. The effects of water on deck and of operational parameters (draught, centre of gravity and trim) were also investigated. The results of the study, presented in graphical form, can provide valuable assistance to the designer when determining subdivision characteristics at the very early stage of the design process, resulting in optimal, efficient and safe ships.     

航运市场遇寒冬海事服务前行——海事机构帮扶港航企业应对金融危机影响

受金融危机影响,全国港口吞吐量增幅连续下滑,航运市场运价大幅下挫,船舶制造订单严重减少,水运施工企业困难开始显现.航运业、船舶修造业、港口生产等各方面都面临着严峻的形势和挑战.     

Fast direction of arrival algorithm based on vector-sensor arrays using wideband sources

An acoustic vector sensor （AVS） can capture more information than a conventional acoustic pressure sensor （APS）. As a result, more output channels are required when multiple AVS are formed into arrays, making processing the data stream computationally intense. This paper proposes a new algorithm based on the propagator method for wideband coherent sources that eliminates eigen-decomposition in order to reduce the computational burden. Data from simulations and lake trials showed that the new algorithm is valid： it resolves coherent sources, breaks left/right ambiguity, and allows inter element spacing to exceed a half-wavelength.     

深基坑阿工程变形特性及有限元分析

通过Ansys有限元软件应用工程实例,对深基坑工程的变形进行数值计算和现场实测.研究结果表明,采用平面应变有限元法可以得到与实测值较吻合的结果.文中方法对实际工程设计、施工有一定的指导作用.     

西霞院反调节水库建设对焦枝铁路黄河特大桥的影响分析及采取的防护措施

对黄河小浪底水利枢纽西霞院反调节水库建设给焦枝铁路黄河特大桥所造成的影响进行了详细分析,并采取了相应的防护措施,消除了黄河铁路特大桥的安全隐患.     

信息分发模型研究

针对大量研究工作主要关注信息分发本身的设计和实现而对信息分发模型研究较少的问题,提出一种通用的信息分发描述模型,描述战场环境下的复杂信息分发模式,为信息分发系统的设计和研制提供指导和帮助.结合提出的描述模型,给出四种信息分发模式,供研究人员参考.     

构建高可用的舰载作战指挥信息系统

通过数学模型二元元件的可用性分析,为选择高可用方案提供理论量化分析参考,在此基础上分析舰载作战指挥信息系统中高可用的关键技术,给出高可用舰载作战指挥信息系统的体系结构.     

在职船员医护技能教育模式探讨

根据国际海事组织的要求,到2002年我国的船员都将具有基本的医疗常识和技能,特别是船长、大副必须通过高级医护的培训并取得合格证书.所以,如何在短时间内对在职而且年龄较大的学员进行医护素质和技能的提高需进行深入研究.