简介:Mostoftheinvestigationsregardingfrictionstirwelding(FSW)ofaluminumalloyplateshavebeenlimitedtoabout5to6mmthickplates.InpriorworkconductedthevariousaspectsconcerningtheprocessparametersandtheFSWtoolgeometrywerestudiedutilizingfrictionstirweldingof12mmthickcommercialgradealuminumalloy.Twodifferentsimple-tomanufacturetoolgeometrieswereused.TheeffectofvaryingweldingparametersanddwelltimeofFSWtoolonmechanicalpropertiesandweldqualitywasexamined.Itwasobservedthatinordertoachieveadefectfreeweldingonsuchthickaluminumalloyplates,toolhavingtrapezoidalpingeometrywassuitable.Adequatetensilestrengthandductilitycanbeachievedutilizingacombinationofhightoolrotationalspeedofabout2000r/minandlowspeedofweldingaround28mm/min.Atverylowandhighdwelltimetheductilityofweldedjointsarereducedsignificantly.
简介:WedevelopedadetailedsimulationmodeloftheArcticmarinetransportsystem(MTS)foroilplatformPrirazlomnaya.Themodelhasamultidisciplinarynatureandinvolves:sub-modelsofvarioustransportandtechnologicalprocesses;stochasticweathergeneratortoobtaintimeseriesof15environmentalparameters;andcontextualplanningalgorithmtobuildvoyageplanconsideringseveraltypesofshipsandcargoes.Weusedasignificantamountofrealoperationaldatatoidentifymodelparametersandtoproveitsstatisticalreliability.Ourmainscientifictaskistoinvestigatetheinteractionofvariousprocessesofadifferentnature,whilethepracticalaimistofindasetofmeasurestoincreasetheefficiencyofMTS.Theresultsofthestudyrevealmanyexamplesofthemutualinteractionofvariousprocessesthatneedtobeconsideredatthedesignstagetoavoidtechnicalmistakes.ThestudyformedabasisformakingmanagerialdecisionsatthetoplevelofGazpromNeftShelfCompany.
简介:文章从句酷批改网在作文智能评阅系统的优势出发,设计了使用句酷批改网评阅作文的实证研究,研究结果表明.英语作文评阅系统可以提高学生写作的积极性,但教师参与学生作文评阅对学生作文水平的提升有重要影响,两者要相互结合才能取得理想效果。
简介:竖轴固定偏角直叶片潮流水轮机的自启动能力较差。文章根据模型试验的观测分析,利用Fluent软件模拟计算在不同水流速度下叶片在圆周不同位置时的潮流水轮机自启动性能,并与加装叶柵附体的水轮机进行比较,得出加装叶柵附体可以提高水轮机的自启动性及水轮机的水动力性能。