深海中极低频时谐环形电流源电场的解析解

将海水看作线形、均匀、各向同性的半无限大导体空间,利用汉克尔变换及开尔文函数近似展开式求得极低频时谐点电极产生的电场强度解析式,然后利用矢量叠加方法可以推导出极低频时谐环形电流源产生的电场强度解析式,进而可以计算海水中任意场点的电场值.     

浅海条件下垂直时谐电偶极子在空气中的磁场

为分析船舶轴频磁场在空气中的传播特性,把船舶的轴频电流等效为垂直时谐电偶极子,对3层介质中垂直时谐电偶极子在空气层产生的磁场进行求解。借助麦克斯韦方程组和电磁场边界条件建立了垂直时谐电偶极子在空气中矢量磁位的模型,由矢量磁位推导了磁场三分量的表达式,并利用快速汉克尔变换对包含贝塞尔函数积分的磁场进行数值计算。最后,通过碳棒电极在海水水池中的实验,验证了本文的实用性和有效性。     

四分层媒质中垂直时谐电流产生的电场

为了研究舰船螺旋桨转动产生的轴频电场在浅海中的分布规律,在麦克斯韦方程理论基础上推导了四分层媒质中垂直时谐电流在本层导电媒质中产生的电场理论公式,并通过数值方法仿真分析了电场强度三分量的空间分布规律以及与海底电导率的关系。结果表明,电场纵向分量呈双峰对称分布,而横向和垂向分量呈单峰对称分布,当场源距离较大时海底电导率大小对场强影响十分明显,电导率越小水平方向场强越大而垂直方向场强越小。     

海水中偶极子电场的实验研究

利用镜像法,在三层模型下,推导了海水中任意方向电偶极子在海水中产生水下电场的表达式,并对其进行了理论仿真和实验验证,实验结果表明,推导方法和表达式正确。     

深海中垂直静态电偶极子电位及电场分析

通过建立电场在深海环境下的空气-海水两层模型,采用镜像法,得到深海模型中垂直静态电偶极子的电位和电场分布解析表达式,在此基础上,进行电位和三分量电场仿真计算,分析了两层模型下垂直静态电偶极子的电位、电场强度的分布特性,得到它们随海水深度变化的规律。     

浅海中稳恒环形电流源电场数值仿真

将海水看作线形、均匀、各向同性的半无限大导体空间,建立点电极模型,然后利用矢量叠加方法可以推导出极低频时环形电流源产生的电场强度的解析分析式,运用文中推导的电场强度的解析分析式,可以计算海水中任意场点的电场值。     

浅海中时谐水平电偶极子定位研究

浅海中时谐水平电偶极子定位技术是利用舰船轴频电场信号对舰船进行定位的理论基础.文章提出了一种基于遗传算法的时谐水平电偶极子的位置寻优方法.只需在海水中布置一个电场传感器,测得相应位置的X、Y、Z方向电场强度模值.在合适的坐标系下,结合浅海中时谐水平电偶极子的电场传播公式和遗传优化算法建立位置计算模型,就能精确地确定该偶极子在海水中的位置.给出了仿真计算,结果表明该定位方法具有较高的定位精度和可行性.     

海洋环境电导率对舰船水下电场特性的影响

利用直流电偶极子阵列模型和时谐电偶极子分别计算了舰船稳恒电场和轴频电场随海洋环境电导率的变化情况。结果表明,舰船电场随着海水电导率增大而减小,低电导率海水的电场幅度要明显高于高电导率海水。高阻海床对电流具有排斥作用,导致深海环境下舰船电场水平分量要小于浅海环境下电场水平分量,垂直分量则大于浅海环境下垂直分量,并且水平分量幅度随着海床电导率的增大而减小,垂直分量幅度随海床电导率的增大而增大。因此,对实测数据进行处理时,必须考虑海洋环境电导率参数,采用空气—海水—海床3层模型研究舰船电场分布。     

浅海中四桨运动舰船产生的轴频电磁场

舰船轴频电磁(EM)场可应用于新型鱼雷武器引信,运动舰船轴频电磁场建模可通过运动的垂直时谐偶极子实现。本文根据单个运动垂直时谐电偶在海水中固定场点产生的电磁场公式,采用基于汉克尔变换的快速FFT算法得到t时刻在固定场点产生的电磁场,通过推导得到4个运动垂直时谐电偶极子在固定场点产生的电磁场公式。通过推导的公式对四桨运动舰船的轴频电磁场实现仿真。     

深海中四桨运动舰船产生的轴频电磁场研究

舰船轴频电磁（EM）场可应用于新型鱼水雷武器引信,运动舰船轴频电磁场建模可通过运动的垂直时谐偶极子实现。本文根据单个运动垂直时谐电偶在海水中固定场点产生的电磁场公式,然后采用基于汉克尔变换的快速FFT算法得到t时刻在固定场点产生的电磁场,最后通过推广得到四个运动垂直时谐电偶极子在固定场点产生的电磁场公式。通过推导的公式对四桨运动舰船的轴频电磁场实现了仿真。     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;     

33rd International Conference on Ocean,Offshore and Arctic Engineering （OMAE2014）

正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

The 11th International Conference on Hydrodynamics (ICHD 2014)

正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.     

第十二届深水操作会议和展览会(英文)

正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.