简介：Inconsideringthetheoryofstructuraldynamicoptimizationdesign,adesignmethodofthestructuralstyleofshipcompositebracewithrigidvibrationisolationmasswasstudied.Twokindsofstructuraldynamicoptimizationformulationsminimizingthevibrationaccelerationofthenon-pressurehullontherestrainingconditionofthegrossweightoftheshipcabinwereestablished:1)dynamicoptimizationofthesectionaldimensionsoftherigidvibrationisolationmassinthecompositebrace;2)dynamicoptimizationofthearrangingpositionoftherigidvibrationisolationmass.Throughtheoptimizationresults,sectionaldimensionsandthearrangingpositionoftherigidvibrationisolationmasswithbetterperformanceinreducingvibrationweregained,andsomereferencewasprovidedforpracticalengineeringdesignsaswellasenrichmentofthedesignmethodofanovelshipvibration-isolationbrace.

简介：Rigidblockingmassesarelocatedinthetypicalbasestructureofapowercabinbasedontheimpedancemismatchprinciple.Bycombiningtheacoustic-structuralcouplingmethodandstatisticalenergyanalysis,thefull-bandvibrationandsoundradiationreductioneffectofvibrationisolationmasseslocatedinabasestructurewasresearched.Theinfluenceoftheblockingmass’cross-sectionsizeandshapeparametersandthelayoutlocationofthebaseisolationperformancewasdiscussed.Furthermore,theeffectivenessofrigidvibrationisolationdesignofthebasestructurewasvalidated.Theresultsshowthatthemediumandhighfrequencyvibrationandsoundradiationofapowercabinareeffectivelyreducedbyablockingmass.Concerningweightincrementandsectionrequirement,suitablyincreasingtheblockingmasssizeandsectionheightandreducingsectionwidthcanresultinanefficiency-costratio.

简介：4月，中国中小型炼油厂进口强劲带动了油轮运输市场的一拨上涨行情，贡献了需求增量；男一方面OPEC减产、美国页岩油补位，催生了美国至中国的长距离原油运输需求，VLCC运价月初得以恢复。后期随着“五一”假期临近，询盘减少，价格回落。苏伊士油轮运价也在中印两国需求带动下持续攀升，同时俄罗斯对中国的出口也给予了阿美拉型油轮运价有力支撑。

简介：Basedontheprincipleofimpedancemismatching,theperformanceofrigidvibrationisolationmassinimpedingvibrationwavepropagationwasdiscussedfromtheperspectiveofwaveapproach.BasedonFEM,theinfluenceofitsweightaswellasthecross-sectionshapeparametersontheisolationperformanceofrigidvibrationisolationmasswasstudiedthroughnumericalsimulation.Theresultsshowthatrigidvibrationisolationmasscaneffectivelyimpedethepropagationofthemediumandhighfrequencyvibrationwaves,andtheheavierthevibrationisolationmass,thebettertheisolationperformance.Forlowfrequencywaves,thevibrationisolationeffectisnotsoobvious;forarectangularvibrationisolationmass,theisolationperformancecouldbeeffectivelyimprovedbyincreasingthecross-sectionheightandreducingthecross-sectionwidth.Ausefulreferencewasprovidedfortheapplicationofrigidvibrationisolationmassestothevibrationisolationandnoisereductionofshipstructure.

简介：5月，油价未得到提振，运价反而受原油出口量下降预期的影响持续回落。尽管美国石油库存有所下降，但在国内页岩油复产的背景下，进口需求并未得到推动。亚洲炼厂夏季检修带来的需求疲软，进一步增大了消化前期集结运力的难度，而船东消极的拆船行为也无益于运价的修复。

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简介：利用Matlab工具箱编写程序对MTU16V396TC53柴油发电机组的双层隔振系统进行计算,分析了采用不同中间质量、钟状罩刚度、上下减震器的刚度及减振器阻尼系数等对隔振效果的影响,为该机组的隔振器选用提供参考依据.

简介：注浆法是将某些能固化的浆液注入岩土地基的裂缝或孔隙中,以改善其物理力学性质的方法.注浆的目的是防渗、堵漏、加固和纠正建筑物偏斜.

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简介：文章通过对亚里士多德在《尼各马科伦理学》中的技术以及人的德性等伦理学思想进行评析,联系现代社会技术发展中存在的一些技术伦理问题的反思,提出以亚里士多德的“中道”思想,对技术进行理性的思考、选择,提出技术在实践中接受伦理的规范,寻求社会的普遍性,实现技术价值,最终达到“至善”,获得幸福.

简介：区块链技术实现集装箱重量数据共享,以满足全球规则。英国物流软件供应商将发布采用区块链技术的软件实现了全供应链集装箱重量信息的存储、读取和管理。此前,区块链技术曾被广泛讨论,却鲜被使用。

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简介：当前,航运业对区块链技术显得格外青睐,许多航运龙头企业对区块链技术的力挺,引起业内广泛关注,有人认为,区块链改变航运业的时代将要到来……在科技日益革新的今天,区块链已成为目前最火的名词。区块链具有自身独特的特性,去中心化、交易点对点、不可篡改的特性可以实现机器信任;交易不可逆、信息加密的特性可以实现价值传递;信息点对点、不可篡改还可以实现智能合约。

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简介：1405年,伟大航海家郑和,奉明成祖朱棣之命,率领庞大船队起锚远航,出使中国南海以西的国家和地区,称为＂郑和七下西洋＂。610年过去了,当我们站在长151.18米、宽61.6米的＂宝船＂模型前,当我们再次扬帆远航,重走海上丝绸之路时,我们仍要感叹于中国古代那些先进的造船和航海技术。从技术发展的角度来看,郑和下西洋已显示出我国古代在造船和航海方面的辉煌成就。

简介：Tosolvethedimensionallimitationsofphysicalmodelsintests,anequivalentwaterdepthtruncateddesignforaclassicalSPARworkingin913mwaterwasinvestigated.Thewaterdepthwasreducedto736mandthento552m.Asthiswasdone,themooringlinelengths,EAvalue,andmasspermeterwereadjusted.Truncationrulesandformulasforparametersandtruncationfactorswereproposed.SPARstaticcharacteristicsweremadetobeconsistentwiththoseatfullwaterdepth.Thenfurthertime-domaincoupledanalysiswascarriedoutfortheSPARwhenthemooringsystemexperiencedwaves.Themooringlinesweresimulatedbyquasi-staticmethod.Globalresponsesandmooringlineforceswerefoundtoagreewellwithtestresultsforaprototypeatthatwaterdepth.Thetruncationmethodprovedtoberobustandreliable.