Structural stability of polymer matrix composite panels in fire

Development in advanced composite fabrication technology offers the clear prospect of cost effective application of polymer matrix composites for large load-bearing structures. However, polymer matrix composites can be severely degradated under the thermal condition caused by fire. This paper addresses the compressive load-bearing capacity for polymer matrix composite panels in naval structures and civil infrastructures under the combined thermal–mechanical condition. The failure modes arising from structural instability for single skin and sandwich panels in such combined thermal–mechanical condition are the focus in this study. The thermal field under fire heating and the degradation of mechanical properties with elevated temperature are discussed. Analytical solutions for these mechanical failure modes are presented for design considerations. The approach to the development of a quantitative methodology for fire protection design is discussed in the context of the analyses and the experiments. Design diagrams are constructed to design mechanical loads for given fire protection time, and on the opposite, to design fire protection time for given mechanical loads.     

加强贵港站铁路水路的联运

1贵港站概况 　　1.1地理位置 　　贵港站位于贵港(地级)市内,黎湛铁路、南梧二级公路、郁江水运航道的交汇处.铁路往上可通内陆各地,往下可通广东或出海,是大西南铁路货物发往广东或出海的主要通道;公路四通八达,可通全国各地;水路上通南宁,下通梧州、珠江三角洲等,也可从珠江三角洲出海通往粤、港、澳及东南亚沿海地区.贵港站衔接的十大专用线单位有九家位于江边,其中三家拥有下水能力,还有一个即将开通的新港专用铁路线,更有强大的下水能力,是华南地区最大的内河港口,是大西南与粤、港、澳及东南亚地区之间最便捷的重要通商口岸.……     

基于单目标规划的弹药最佳运输策略分析

结合联勤体制下我军弹药调运的特点，基于最低运费的原则，建立了弹药运输问题的单目标线性规划模型，并通过表上作业法求解了实际算例．结果表明：该方法简便、灵活、有效，将其运用于军事运输领域，可为部队弹药供应节约运费提供科学依据．该方法也同样适用于实现最快、最安全运输等其他单目标调运问题的研究．     

数字图像识别技术在对危险化学品船舶监控中的应用

随着水上交通的发展,通过船舶载运的货物种类日趋繁多,其中包含大量有毒有害的危险化学品.与其他货物相比其具有更高的危险性和破坏性,因此应该采取更为有效的监管措施以避免重大危害事故的发生.港口CCTV的广泛应用为此提供了便利的硬件条件.据此本文重点讨论了数字图像识别技术在对危险化学品船舶监控中的应用的前景及技术细节.     

基于粗精双线区域生长法的多目标识别

在分析多目标害虫图像特性的基础上,提出了基于粗精双线区域生长法的多目标识别算法。在多目标图像中,为了减少运算量、提高实时性,先用迭代阈值法对图像进行预处理,将图像二值化,然后使用改进的区域生长法,使用粗精双线种子生长法有机结合的方法获得图像中的各个目标的四个边缘坐标,然后在原图中进行目标分离,重构单个目标并进行标示。实验结果表明,该算法可准确快速地实现对多个目标的识别。     

Carbon Deposit Incineration During Engine Flameout Using Non-Thermal Plasma Injection

In order to investigate the influence of initial regeneration temperatures on diesel particulate filter (DPF) regeneration, an experimental study of DPF regeneration was implemented using a dielectric barrier discharge (DBD) reactor, aided by exhaust waste heat after engine flameout. DPF trapping characteristics and carbon deposit mass were discussed to facilitate further data analysis and calculation. DPF regeneration was then investigated by comparison analysis of deposit removal mass, backpressure drop, and internal temperature change. The results revealed that a large amount of particulate matter (PM) was deposited in DPF with a high filtration efficiency of about 90 %. The deposit removal rate and percentage drop of the backpressure both maximized at the initial temperature of 100 °C. During DPF regeneration, the sharp rise of internal temperature indicated vigorous PM incineration and high CO₂ emission. The results successfully demonstrated DPF regeneration using non-thermal plasma injection during engine flameout, and prominent heat durability was achieved in this method.     

航海人员应对地震海啸的措施

概述地震海啸的成因、发生状况及危害,介绍海啸预警机制以及航海人员及早发现海啸的辅助方法,讨论航海人员在不同状况下应对地震海啸的措施,以期对遭遇海啸威胁的航海人员有所帮助。     

高速公路收费站通行能力分析

高等级公路收费站的通行能力直接影响着路段通行能力,从而在总体上制约着公路的交通运行状况。因此提高高等级公路收费站的通行能力和服务水平,是改善高等级公路通行能力及服务水平的有效方法。本文根据高等级公路收费站交通流特性的分析,建立了收费站的排队模型,计算出了同一条车道在不同比例下的ETC车辆条件下和多车道情况下不同条数ETC车道的收费站的通行能力。     

基于晶闸管串联的高压电机软起动

介绍了基于晶闸管串联的高压异步电动机软启动器,并推导出串联晶闸管的数学模型,应用该等效模型对高压电动机的软启动过程进行了仿真,为分析和设计基于晶闸管串联的高压异步电动机软启动器提供了一个有力的工具.     

船舶设计风险管理初探

分析了船舶设计工作过程中不同来源的风险,指出了我国船舶设计风格管理的现状,并提出了较为简便的风险管理基本方法及过程,具有较好的实际参考价值。