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621.
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623.
针对地方院校带有建材特色的材料科学与工程专业人才培养目标的定位,结合学校实际情况,提出应用型人才培养体系,构建具有学校特色的课程体系。 相似文献
624.
The galvanic corrosion behaviour of alumiuium 3004 - ∝ brass with different area ratios was studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios, viz. AAluminiurn:A∝ brass, studied were 0.125, 0.25, 0.5, 1, 2, 4 and 8. The galvanic corrosion behaviour of the metals was studied in terms of the relative increase in the corrosion rate of aluminium due to galvanic coupling with oc brass, the relative decrease in the corrosion rate of ∝ brass due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with ∝ brass. The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders arid the surfaces of the interface of aluminium in contact with ∝ brass. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium as a result of galvanic corrosion was highlighted in terms of pit depth, size and density of pit, using a high resolution microscope. The most favourable area ratio of aluminium - ∝ brass in marine atmosphere in terms of gravimetric corrosion rate is 8:1 and the most unfavourable area ratio of aluminium - ∝ brass is 1:4. 相似文献
625.
Evgeny I.Veremey 《船舶与海洋工程学报》2014,(2)
The objective of this work is the analytical synthesis problem for marine vehicles autopilots design.Despite numerous known methods for a solution,the mentioned problem is very complicated due to the presence of an extensive population of certain dynamical conditions,requirements and restrictions,which must be satisfied by the appropriate choice of a steering control law.The aim of this paper is to simplify the procedure of the synthesis,providing accurate steering with desirable dynamics of the control system.The approach proposed here is based on the usage of a special unified multipurpose control law structure that allows decoupling a synthesis into simpler particular optimization problems.In particular,this structure includes a dynamical corrector to support the desirable features for the vehicle’s motion under the action of sea wave disturbances.As a result,a specialized new method for the corrector design is proposed to provide an accurate steering or a trade-off between accurate steering and economical steering of the ship.This method guaranties a certain flexibility of the control law with respect to an actual environment of the sailing;its corresponding turning can be realized in real time onboard. 相似文献
626.
In the presence of biofilms, stainless steels(SS) exhibits an increase in corrosion potential, called ennoblement. In the present study, the corrosion potential(Ecorr) behavior of the duplex SS UNS S32760 was recorded simultaneously with the in situ marine biofilm formation in two areas at Arraial do Cabo,Southeastern Brazil. The biofilm at Forno Harbor(an anthropogenically disturbed area) was characterized by higher relative abundances of Bacteria at day 2, followed by diatoms(especially Navicula sp.) on day 10 and dinoflagellates on day 18,whereas no clear trend was recorded at Cabo Frio Island(an undisturbed area). The ennoblement of Ecorr values was site-dependent. In a complementary laboratory assay, biofilms were removed and the Ecorr values registered in sterile conditions for the subsequent 10 days and corroborated in situ results. Understanding biofilms and SS interactions has important implications for materials science and engineering decisions as well as helping to fill in important gaps in this knowledge. 相似文献
627.
文中通过FSA方法,分析构成海事事故的危险因素,提出实际有效的风险控制措施,基于有效性和经济性评估风险控制方案,从而得到最后的选择结果,完成本次基于FSA的秦皇岛港通航安全的研究。 相似文献
628.
Hui Ding Haigen Xu Jun Wu W. J. F. Le Quesne C. J. Sweeting N. V. C. Polunin 《Coastal management》2013,41(5):443-457
Marine ecosystems of the East China Sea are rich in biodiversity, with 12,933 species of which approximately 47.7% are endemic. As anthropogenic impacts are intensifying, fishery resources and biodiversity in the East China Sea are under threat from overfishing, habitat loss, pollution, and biological invasions. Marine protected areas (MPAs) and other spatial management measures are believed useful tools to protect and restore biological resources. Seventeen nature reserves, seven special marine reserves, and three fishery resource conservation zones covering a combined area of 102,156 km2 have so far been established in the Chinese East China Sea in order to protect fishery resources, biodiversity, and marine landscapes. This article provides a review and inventory of MPAs in the Chinese East China Sea as implemented by the People's Republic of China. 相似文献
629.
发展海洋渔业可以缓解国家粮食安全压力,拓宽中国海洋渔业发展空间,维护国家海洋权益。专业化渔业物流船队是保障和支撑海洋渔业发展的重要组成部分,文章从不同的服务对象角度对渔业物流船队进行了划分,详细介绍了各类型渔业物流船队的发展历程、主要做法和取得的成效,指出了我国的渔业物流船船龄大,装备陈旧,自动化程度低和信息化水平弱等严重制约我国渔业物流船队发展的问题,提出了全面推进渔业物流船队的专业化建设、推动渔业物流船装备自动化革新、提升渔业物流船的信息化水平等实现渔业现代化的经验启示。 相似文献
630.