Quik SCAT与ASCAT-A卫星海面风在中国近海风电规划区的差异

利用Quik SCAT(QS)和ASCAT-A(AS)的遥感微波散射计海面风资料,分析中国近海风速的气候分布特征,并比较QS与AS的差异,结果表明：QS和AS的累年平均风速均显示台湾海峡风速最大,巴士海峡、越南南部以东海域次之,长江口以北风速偏小。2008年QS和AS同期运行期间,二者平均风速均小于各自的多年气候值;QS与AS的平均风速差值台湾海峡最大,高达0.5 m/s～1.5 m/s;QS与As交叉风速相关系数达0.95时,3.5 m/s以下的风速区间内AS明显大于QS,10 m/s以上的风速区间内QS明显大于AS;不同风速频率分布,风速在8 m/s以下时,QS风速频率明显小于AS,而9 m/s以上时,QS则明显大于AS。6个重点风电规划区累年风速频率,江苏到闽中海域的风速频率分布趋于正态分布,且2 m/s～8 m/s风速的频率由北向南逐渐减小,11 m/s风速以上频率逐渐增大;阳江和粤东则表现呈双峰分布。2008年,6个重点风电规划区的风速频率,除江苏风电规划区与多年气候分布几乎一致外,浙江、闽北和闽中均呈现明显的双峰分布,粤东和阳江则呈现不规则的多峰分布。     

服务区域融合发展的航道发展思路——以南通、融合发展为例

本文通过深入分析融合发展的内涵及要求,以及区域融合与航道发展的互动机理分析,一方面可以为"都市圈"、"城市群"、"大都市区"等城市连绵区的航道发展提供一些参考,另一方面也可以为跨地区航道布局思路、建设时序、管理机制提供一种研究路径。     

一起船舶碰撞案例的思考

通过分析一例远洋船舶"惠荣"轮和"鹏延"轮碰撞事故,分析各方的主体责任,总结此类事故中各方应采取的应对措施,并提出一些建议和看法,用于对类似海事提供参考,确保船舶通航安全。     

既有小区“海绵化”建设措施研究

既有小区"海绵化"改造是海绵城市建设的重要环节,笔者分析了既有小区在"海绵化"改造过程中可能存在的问题,进一步提出了"海绵小区"建设的具体措施,以期为开展海绵城市改造提供一些可借鉴的经验。     

企业档案管理在ISO/TS16949质量管理体系运行和认证中的作用

一、前言ISO/TS16949是国际汽车工作小组(International Automotive Task Force,简称IATF)与国际标准化组织质量管理与质量保证技术委员会(ISO/TC176)在ISO9001基础上,结合美国三大汽车公司的QS9000、欧洲诸国汽车行业质量管理体系(德国VDA6.1,意大利VSQ,法国EAQF)要求而制     

钢质海船尾轴换新工艺策划

在一般的钢质海船修理中,尾轴换新的情形并不多。本文以"将军2"轮的尾轴存在严重裂纹而换新的工程实例,介绍了该尾轴换新的工艺策划过程及项目,目的在于为以后可能的钢质海船尾轴换新工程提供一些参考资料。     

海上风电安装船“福船三峡”跨港区拖航的风险评估与防范措施

海上风电安装船具有附加值高、造价高、设计建造难度大的特点。福建省第一艘自主建造尚未试航的海上风电船"福船三峡"计划从厦船重工3号码头拖至海翔码头继续安装剩下的25米桩腿。作为引航员,有幸指挥拖轮拖航其至海翔码头,在此介绍一些拖航经验与同行交流、探讨,希望能够提供一些有益的借鉴。     

“育鹏”轮实习船的电气优化设计分析

对大连海事大学多用途载货教学实习船"育鹏"轮的电气生产设计中几点方法进行介绍,由于"育鹏"轮具备多种功能,并可用于多种学科的科学研究和试验,在船舶建造过程对电气设计提出更高要求,对船舶电气设计过程中应用的几点优化方法做了分析,为以后的相关船舶设计提供一些借鉴。     

企业档案管理在IS0／TS16949质量管理体系运行和认证中的作用

一、前言 IS0／TSl6949是国际汽车工作小组（International Automotive TaskForce，简称IATF）与国际标准化组织质量管理与质量保证技术委员会（IS0／TCl76）在IS09001基础上，结合美国三大汽车公司的QS9000、欧洲诸国汽车行业质量管理体系（德国VDA6．1，意大利VSO，法国EAQF）要求而制定的。     

MC柴油机最低气缸注油率判断的实例分析

对3个MC柴油机气缸油调节过程中发生问题的实例进行分析,就如何判断实际的最低气缸注油率,准确定位主机缸套润滑"最佳运行注油率",提供一些经验。     

对规范JTJ 298—1998 的几点建议

在斜坡堤的设计中,堤心石规格选取关系到工程的实际施工可能性以及工程造价;人工护面块结构类型的选择关系到断面整体稳定性以及块体的使用耐久性;护面块稳定质量计算公式用于人工块体和自然块石时应有不同的要求。规范JTJ 298—1998《防波堤设计与施工规范》中的条文对上述几项内容只进行了简单描述。针对上述内容,对规范JTJ 298—1998的条文提出几点建议。     

基于GMM和枪声的军事环境判别

枪声在军事环境下是一个令人高度重视的声音信号。针对其所含信息量的重要性,提出了一种基于枪声检测的军事环境判断方法。首先利用基于中值滤波的算法检测出枪声的起止点;采取反应人耳听觉机理的声音信号动态特征-Mel倒谱系数描述声音信号;然后利用基于高斯混合模型的枪声检测及识别系统完成对枪声的分析从而实现对当前军事环境的判断。实验结果证明了该方法的准确性和有效性。     

间隙对拼组式浮桥静态响应的影响分析

为了减小浮桥在通载状态下的结构内力及浮桥拼组拆卸的方便,拼组式浮桥通常在设计的时候就在舟节之间留有一定的连接间隙.在以往的分析中大多忽略了这种间隙对浮桥变形和受力的影响,而简单地将浮桥简化为连续或者铰接梁体系进行数值或者解析求解,这种方法并不能准确地给出桥节之间连接间隙的存在及其大小对浮桥静态响应的影响.本文以拼组式浮桥的连接间隙为研究对象,建立全桥分析的三维有限元模型,并用非线性单元的组合对浮桥连接件的力学特性进行有限元模拟,通过计算与试验结果的比较,表明了本文方法的正确性;在此基础上本文研究了浮桥在静载荷作用下的位移响应及不同位置的连接件内力与连接件间隙之间的关系,为此类浮桥的设计提供了必要的参考,并为其后续的动力分析提供了必要的理论依据.     

海上油气平台可燃气体探测器的布置、选型、安装和维护

在海上平台油气生产中，有效地利用可燃气体探测器来检测海上生产设备的泄漏状况，并及时采取相应的保护措施，是保证油气生产和人身安全的重要一环。但目前对海上油气平台可燃气体探测器工程设计的系统研究却鲜见于国内外的工程文献中，针对这一现状，在研究国内外现有规范和标准以及工程设计经验的基础上，通过分析可能产生泄漏的工艺设备、可燃气体性质和外部环境等因素来确定可燃气体探测器的物理位置，同时完成可燃气体探测器的选型，并根据现场的工作环境合理安装可燃气体探测器，最后总结探测器使用维护中需要注意的问题。对可燃气体探测器的布置、选型、安装和维护的系统总结和分析研究为海上平台火气系统的设计提供了技术支持，从而进一步保障海上油气平台的生产安全。     

潜艇超空泡技术应用分析

结合目前国内外超空泡技术的发展,论述发展超空泡潜艇的必要性,介绍了超空泡技术基本原理。依据超空泡鱼雷的配置,提出“变形空化器”的概念;论证超空泡潜艇推进和控制系统的选择;分析导引设备和尾舵的作用以及可能出现的问题。结合4种超空泡航行体稳定模式,分析超空泡潜艇水下稳定性问题,提出超空泡潜艇发展设想。结合对潜艇操纵研究,分析超空泡潜艇的水动力特性问题。同时,对 Suboff潜艇模型进行了流场特性的仿真计算,结果表明：潜艇的头部、指挥室的迎风面、指挥室的两侧艇体和潜艇的尾翼均存在一定的沾湿区域。基于此结果,提出相应的改进方案。对超空泡潜艇未来主要工作进行展望。     

Land use/transport models and economic assessment

This paper discusses the economic assessment of policies using land use/transport models. It argues that conventional forms of assessment focussing only on transport changes can underestimate the economic benefits of a policy. The paper argues that the benefits need to be measured by the changes of prices at the end of a trip and not just by the changes in travel costs. Models that do not estimate the changes of prices at the end of a trip cannot properly assess the impact of a policy.The model used in this paper is based on the MEPLAN software and estimates the location of households and employment and the interaction between them. It also estimates the cost of living for households and the production costs for employment. With these costs, it is possible to calculate the wider economic benefits beyond transport.The paper illustrates the assessment of policies for the Cambridge sub-region involving investment in public transport, orbital highway and congestion charging policies. The results forecast by the model are assessed in terms of the conventional cost-benefit using traveller’s surplus as benefits and compared with a wider assessment measure of compensation variation. It demonstrates that the last measure encompasses the wider benefits associated with transport policies which are not taken into account in conventional cost-benefit analysis.     

从河床演变观点评荆江碾子湾河道的整治

长江下荆江河段的碾子湾河道长度只有２８ｋｍ,分布着严重碍航的碾子湾浅滩,藕池口浅滩,石首锐弯与被泥沙沉积的石首港。１９８０年以来碾子湾河道发生严重的侵蚀与沉积。１９９５年２月至３月因碾子湾浅滩严重沉积使航道恶化,断航达２９天,约５００多艘江轮与６万多名旅客相继滞留在碾子湾河道上,在长江中游近代航运史上实属罕见。本文从近４０多年来碾子湾的河床演变和鱼尾洲护岸工程角度评述碾子湾道与石首港恶化的原因,这     

Multi-scale modeling of fatigue crack propagation applied to random sequence of clustered loading

Fatigue crack propagation in marine structures is obviously governed by mechanics of the considerably different four levels of multi-scale problems. Problems of structural response to environmental loads have length scale of several hundred meters, whereas possible detectable size of cracks from initial defects in a weld is of the order of millimeters. Once a fatigue crack initiates, crack tip plasticity is of the order of several grain sizes, while the resulting fatigue crack growth in each load cycle is of the order of nanometers. In our previous work, the first author and their associates have developed the so-called CP-System, which can treat the first two multi-level problems as an integrated system. Furthermore, we have incorporated the third level of mechanics by using the stress intensity range corresponding to the repeated tensile plastic deformation ahead of the crack tip. In the present paper, we shall discuss a more rational integral equation-based formulation in order to integrate the third and fourth levels of micro-mechanics to the first two levels of continuum mechanics.The method is then applied to fatigue crack propagation under the effects of random sequence of clustered loading. As an example of the random sequence of clustered load, we shall use the so-called “storm model”. In the crack propagation simulation, we have to take into account of the plastic wake on the crack surfaces, whose thicknesses are influenced by the material parameters involved in the crack growth model. These parameters are first identified by the fatigue tests under combined constant and random loading using a CT specimen. Then, fatigue crack growth is investigated by numerical simulation and fatigue tests for various random sequences of clustered loading. The experimental and numerical results agree quite well with each other, and fatigue crack propagation is found to be considerably retarded under random sequence loading, so that the conventional equivalent stress approach may provide rather conservative results to the real seaway loading.     

On the parameterization of interleaving and turbulent mixing using CTD data from the Azores Frontal Zone

CTD-data obtained in the Azores Frontal Zone using a towed undulating vehicle are analyzed to study the relationship between characteristics of intrusions and mean parameters of the thermohaline field. A self-similar dependence between intrusion intensity and hydrological parameters is obtained. The most well-founded interpretation of the empirical dependence is as follows: (a) the main source supporting intrusive layering is the salt finger convection; (b) the abrupt decrease of intrusion intensity with the reduction of geostrophic Richardson number obtained from the analysis is explained by the beginning of turbulence when salt fingers do not work any longer, so the “driving force” for intrusive motion disappears. These results are consistent with the conclusions of the paper [Kuzmina N.P., Rodionov V.B., 1992. About the influence of baroclinicity upon generation of the thermohaline intrusions in the oceanic frontal zones. Izvestiya Akad. Nauk SSSR, Atmosperic and Oceanic Physics 28 (10–11), 1077–1086]. These conclusions imply that there are three main mechanisms of intrusive layering at oceanic fronts, namely the 2D baroclinic instability of geostrophic flow, the vertical shear instability and the thermohaline instability where the driving source of intrusive motion is double diffusive convection. The baroclinic and thermohaline instabilities can generate intrusions of large vertical scale, while vertical shear instability usually gives rise to thin turbulent layers. Turbulence in these thin layers can prevent salt finger convection and thus destroy the energy source of the intrusive motion conditioned by thermoclinicity. Therefore, the baroclinicity plays two parts in the processes of the intrusive layering: (1) it prevents double-diffusion interleaving by means of turbulence, and (2) it generates intrusions due to the 2D baroclinic instability of geostrophic current. Using features of thermohaline interleaving as a specific tracer of turbulent mixing, we have estimated turbulent mixing coefficient as k_tRi^−0.8 (Ri>1), where Ri is the geostrophic Richardson number. Application of the proposed approach to other frontal zones is discussed.