基于EEDI Ⅲ要求的某新巴拿马型散货船主机选型

针对新巴拿马型散货船主机选型和满足船舶能效设计指数（EEDI）Ⅲ的问题,对新巴拿马型85 000 t散货船主机最小装机功率的评估方法和EEDI进行分析和计算。获取主机最小装机功率参数,对低转速主机机型进行选型,合理选择主机约定最大持续功率（Specified Maximum Continuous Rating,SMCR）和转速,降低主机功率储备和单位油耗。在仅预留适当的主机功率裕度且不配置额外的节能设施或不采用环保新能源的设计方案措施下,确保船舶满足EEDI Ⅲ的要求,为85 000 t散货船主机选型和设计提供参考。     

Geochemical controls on distributions and speciation of As and Hg in sediments along the Gaoping (Kaoping) Estuary–Canyon system off southwestern Taiwan

Surface and box-cored sediments were collected along the Gaoping (formerly spelled Kaoping) Estuary–Canyon system and analyzed for As and Hg contents and speciation, ²¹⁰Pb-based sedimentation rates and various geochemical parameters to elucidate the mechanisms that control natural and anthropogenic inputs of As and Hg from the Gaoping (Kaoping) River (KPR). The contents of As and Hg in surface sediments ranged from 1.84 to 20.7 mg kg^− 1 and from 0.07 to 2.15 mg kg^− 1, respectively, in the estuary and canyon. The concentrations generally decreased from the lower river toward the mixing boundary and then increased toward the estuarine mouth, followed by a slight variation in the canyon. Both As and Hg concentrations correlated strongly with clay, total organic carbon (TOC), Al, Fe and Mn contents in estuarine sediments but not necessary the same cases for canyon surface sediments. The factor analysis of surface sediments shows that the first two factors, which account for 75.6% of the variance, may represent major roles of carriers (clay, Al and Fe–Mn oxides) and TOC in controlling As and Hg distributions, respectively. Accordingly, the spatial patterns of the enrichments of As (1.9–16.2) and Hg (1.8–30.8) with reference to the crust levels follow the individual element's distribution patterns, likely because of deposition variability following inputs from the river. The contents of mobile As and Hg correlated substantially with the contents of both metals that were extracted with 0.1 M HCl. In addition to the major pool in the residual fraction (65–87%), As was relatively abundant in Fe–Mn oxides/hydroxides, whereas Hg was abundant in the organic/sulfide fraction. The deposition and accumulation rates of As and Hg in the canyon clearly decreased as the depth of water increased. The depth distributions of both metals are likely controlled primarily by TOC and Fe–Mn oxides associated factors followed by a contribution from anthropogenic pollution. The metal pollution appears to have increased substantially around 1970, following the economic boom in Taiwan, suggesting that modern sediments in the Gaoping (Kaoping) Canyon were derived from the Gaoping (Kaoping) River (KPR).     

基于信息融合与神经网络PID(比例-积分-微分)技术的潜艇自动舵研究

依据信息融合、神经网络、系统辨识等的理论,本文设计出了基于多层网络的在线自适应神经网络PID控制器,仿真结果表明,神经网络PID自动舵的控制性能要远好于传统的自动舵.     

网络时间协议在海军作战指挥一体化系统中的应用

以网络时间协议为基础，提出了对海军作战指挥一体化系统的网络对时体系结构。     

对空情报雷达组网的关键技术与发展构想

雷达组网作为现代对空情报雷达发展的主要方向,是提高对空情报雷达综合探测能力和电子对抗能力的一种有效途径。文章介绍了有关雷达组网的基本概念,讨论了对空情报雷达组网的关键技术。研究了对空情报雷达组网的发展趋势,提出了未来对空情报雷达的发展构想。     

规划、新建船厂的几个关键要素

船厂工程是一个复杂的系统工程。船厂的总体规划是多学科、多专业技术知识的综合运用,是船厂基本建设的关键工作。通过参与舜天造船（扬州）有限公司的基本建设,作者认为建设一座具有现代造船模式的新型船厂,选址合理、规划准确、决策果断、定位清晰、抢抓机遇等是决定船厂成功与否的关键要素。     

华北地区港口进口铁矿石船型的综合比较

华北地区钢厂进口铁矿石主要通过二程运输、减载运输和直达运输等3种模式,其海运成本因运输模式不同和经由不同的装卸港而有所差异.考虑海运费、铁路运费、港口使用费(包括目的港和中转港)和货损等因素的影响,对多种运输模式和多个装卸港进行铁矿石物流成本的综合分析比较发现,装船港的泊位等级对海运成本的影响较大.而在华北地区港口建设30万t级矿石泊位对减少海运费的贡献较小,我国进口铁矿石的综合物流成本约占铁矿石到岸价的18 ％～32％.     

钢铁企业成品出运全天候码头关键技术

水路运输是钢铁成品出口的重要运输途径之一,然而该出运方式极易受到雨天影响,这使产品周转受到制约、企业蒙受经济损失。本文引出全天候码头设计概念,分析设计要素,对设计关键技术进行探讨。     

The biogeochemical cycling of methane in Ria de Vigo, NW Spain: Sediment processing and sea–air exchange

Methane (CH₄) concentrations were measured in the water column, in sediment porewaters, and in atmospheric air, in the Ría de Vigo, NW Spain, during both the onset (April 2003) and at the end of (September 2004) seasonal upwelling. In addition, CH₄ concentration and stable isotopic signatures (δ¹³CH₄) were measured in porewaters, and sediment methanogenesis and aerobic oxidation of CH₄ were determined in sediment incubations. Surface water column CH₄ (2 m depth) was in the range 3–180 nmol l^− 1 (110–8500% saturation) and followed a generally landward increase but with localised maxima in both the inner and middle Ría. These maxima were consistent with CH₄ inputs from underlying porewaters in which CH₄ concentrations were up to 3 orders of magnitude higher (maximum 350 μmol l^− 1). Surface water CH₄ concentrations were approximately three times higher in September than in April, consistent with a significant benthic CH₄ flux driven by enhanced sediment methanogenesis following the summer productivity maximum. CH₄ and δ¹³CH₄ in sediment porewaters and in incubated sediment slurries (20 °C) revealed significant sediment CH₄ oxidation, with an apparent isotopic fractionation factor (r_c) of  1.004. Using turbulent diffusion models of air–sea exchange we estimate an annual emission of atmospheric CH₄ from the Ría de Vigo of 18–44 × 10⁶ g (1.1–2.7 × 10⁶ mol). This estimate is approximately 1–2 orders of magnitude lower than a previous estimate based on a bubble transport model.     

Ultimate strength assessment of a tanker hull based on experimentally developed master curves

A geometrically similar scaling was made from small-scale specimen to full-scale stiffened panels and then their collapse behaviour is investigated. It is considered that the stiffened panel compressive ultimate strength test was designed according to geometrical scaling laws so that the output of the test could be used as representative of the stiffened panels of the compressive zone of a tanker hull subjected to vertical bending moment. The ultimate strength of a tanker hull is analysed by a FE analysis using the experimentally developed master stress-strain curves which are obtained by the beam tension test and the compressive test of the stiffened panel, and are then compared with the result achieved by the progressive collapse method.