简介：为模仿air-to-refrigerantfin-and-tube蒸发器的稳定的州的行为的一个一般、简单的模型在试管内与详细流动模式的焦点被介绍。为了模仿热，在空气和工作液体之间转，蒸发器被划分成很多控�

简介：Thisstudydevelopedasequentialcouplingfiniteelementproceduretopredictresidualstressesofsteelpipeswithlongitudinalwela\circumferentialweldandspiralweld.Theresultsshowthattheresidualstressinheataffectedzone(HAZ)ishigherthanthatinweldforspiralweldpipe.Forthecircumferentialweldpipeandspiralweldpipe,theresidualstressininnersurfaceishigherthanthatinoutersurface.However,forthespiralweldpipe,theresidualstressininnersurfaceissmallerthanthatinoutersurface.Thehoopresidualstressofcircumferentialweldpipeishigherthanthatoflongitudinalweldpipe,whiletheaxialresidualstressofcircumferentialweldpipeissmallerthanthatoflongitudinalweldpipe.Thehoopstressesforcircumferentialweldpipeandaxialstressforlongitudinalweldpipehaveexceededtheyieldstrengthofbasemetal.Withtheincreaseofhelixangle,thehoopstressdecreaseswhiletheaxialstressincreases.Forthespiralpipe(α=30°to50°),boththehoopstressandaxialstressarerelativelysmall.Thespiralpipe(helixanglerangingfrom30°to50°)ishelpfultoreducestresscorrosioncracking(SCC)anditisrecommendedtomanufacturethesteelpipe.

简介：Theharmonysearchalgorithmisappliedtooptimumdesignsofafunctionallygraded(FG)-carbonnanotubes(CNTs)-reinforcedpipesconveyingfluidsubjectedtomovingload.ThestructureismodelledbyReddycylindricalshelltheoryandthefinalequationsareobtainedbyprincipalofHamilton.Basedondifferentialquadraturemethod(DQM),thedynamicdisplacementofsystemisderived.

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简介：Themechanicalandcorrosionperformanceoflowalloysteeltubulargoodsdependsonthemicrostructureobtainedasaresultofthecombinationofalloyingelementsandmanufacturingprocessparameters.Thebasicdesignphilosophyfortheselectionofthealloyingelementsisruledbythebalancebetweenthesteelcostandthematerialperformance.Followingthisapproachthealloyingsequenceforthemanufacturingoftubularcomponentsinoilcountrytubulargoods(OCTG)applicationisgenerallyMn,C,randMo,usedassubstitutionalelementsinatotaladdedweightconcentrationaround1%upto3%.OtherelementssuchasB,Ti,NbandVareappliedasstrengtheningmicroalloyingelementsformingfineprecipitates.AlackofexperienceisfoundrelatedtotheuseofTungsten(W)onOCTGapplications,althoughWisalsoasubstitutionalelementthatbelongstogroup6oftheperiodictabletogetherwithCrandMo.OntheotherhandWiswidelyaddedforsteelpipesworkinginhightemperatureservicessuchaspowerplantboilers,wherecreepresistanceisneeded.Itisalsoappliedfortoolsteelsenhancingthehardness,wearresistanceandcuttingperformance.TakenintoconsiderationthesimilaritybetweenCr,MoandWandtheapplicationswhereWhasbeenprovenitwasdecidedtoanalyzethefeasibilityofusingWasanalternativealloyingelementforsomeOCTGapplications.AnotherfactorthatdrivesthisstudyisthefactthatWcouldbeacosteffectivesubstituteofMo,dependingonthealloymarketprice.Thispaperisbasedonliteraturereviewandexperimentalactivitydoneonlaboratorysteelsinwhich0.1%Mowasreplacedby0.2%and0.4%W.Thedifferentfindingsinregardswithmanufacturingprocessconsiderations,materialperformanceandthepossibleuseofWalloyedsteelforOCTGapplicationsaresummarized.(1)OpposedtothesusceptibilityshownbylowcarbonwithhighCr-Wcontent,hotcracksarenotexpectedinmediumCsteels(0.2%-0.3%)withWadditionupto1%.(2)Microporosity-relateddefectscouldfo

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简介：Theunbondedflexiblepipeofeightlayers,inwhichallthelayersexceptthecarcasslayerareassumedtohaveisotropicproperties,hasbeenanalyzed.Specifically,thecarcasslayershowstheorthotropiccharacteristics.Theeffectiveelasticmoduliofthecarcasslayerhavebeendevelopedintermsoftheinfluenceofdeformationtostiffness.Withconsiderationoftheeffectiveelasticmoduli,thestructurecanbeproperlyanalyzed.Alsotherelativemovementsoftendonsandrelativedisplacementsofwiresinhelicalarmourlayerhavebeeninvestigated.Athree-dimensionalnonlinearfiniteelementmodelhasbeenpresentedtopredicttheresponseofflexiblepipesunderaxialforceandtorque.Further,thefrictionandcontactofinterlayerhavebeenconsidered.Comparisonbetweenthefiniteelementmodelandexperimentalresultsobtainedinliteraturehasbeengivenanddiscussed,whichmightprovidepracticalandtechnicalsupportfortheapplicationofunbondedflexiblepipes.

简介：Drillpipeproductsarethemostcriticalservicerequirement,thehighestperformancerequirementandthehighestqualityreliabilityOCTGproducts.Throughthecontinuousresearchonsteelmaking,upset,hearttreatment,straighteningandfrictionwelding,Baosteelimprovesthekeytechnicalparameterswhichaffectthequalityofdrillpipe,suchasmaterialpurity,Miuofinternalupsettransitionarea,toughnessandstraightness.Baosteeldrillpipeproductshavemetthedemandingrequirementofdrillingoperations.ByBRPdephosphorizationandLFdesulfurization,theP,ScontentofBaosteeldrillpipeisverylow.TheScontentofS-135drillpipecanbecontrolledinlessthan10ppm.Baosteeldesignsanewclosed-loopcontrolsystemofupsetendinductionheatingsystem.Thesystemusetemperaturemeasurementinsidetheovenandclosed-loopcontrol.Thetemperatureaccuracyofthesystemcanbeguaranteedwithinthe±15℃togetastableupsetquality.TheupsettingprocessofthedrillpipeisoptimizedbyusingpatentedtechnologyandmadetheMiufrom100mmto140mm.Thismakeasubstantialincreaseinfatiguelifeofthedrillpipe.Toimprovetheimpacttoughnessofthedrillpipebody,thedrillpipebodymaterialischangedfromCr-Ni-MosystemtoCr-Mo-Vsystemandtheheattreatmentischangedfromoilquenchingtowaterquenching.Toimprovetheimpacttoughnessofthetooljoint,thetooljointfurnaceisupgradedtoimproveheatingcapacity.Toimprovetheimpacttoughnessoftheweldzone,anewfuzzycontrolsystemofweldzoneheattreatmentisdeveloped.Thetemperatureaccuracyofthesystemcanbeguaranteedwithinthe±5℃togetastableheattreatmentquality.Anewdrillpipestraightnessautomaticdetectiondevicesandself-learningmethodofstraighteningaredevelopedtoachieveautomatedstraightening.Aweldingprocesswithhighspeed,single-stagepressureandhighforgingforceisappliedtoinertiafrictionwelding.Aweldingprocesswithlowspeed,three-stagepressureandlowforgingforceisappli

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简介：Thispaperisconcernedwithahighcharacteristicimageprocessingandrecognitionsystemthatisusedforinspectingreal-timeblemishes,streaksandcracksontheinnerwallsofhighaccuracypipes.Asaregulardetector,theBPneuralnetworkisusedforextractingfeaturesoftheimageinspectedandclassifyingtheseimages,ittakesfullyadvantageofthefunctionofartificialneuralnetwork,suchastheinformationdistributedmemory,largescaleself-adaptingparallelprocessing,highfault-tolerantabilityandsoforth.Besides,animprovedBPalgorithmisusedinthesystemfortrainingthenetwork,andmakingthelearningprocedureofthenetconvergestotheminimumofoverallsituationathighrate.

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简介：Thispaperreviewsthedynamicsofoceanpipesaspiratingfluidandpresentsaselectivereviewoftheresearchundertakenonit.Itfocusesontheequationsofmotion,fluid-solidinteractionattheinletofthefreeendofthepipe,thestabilitymechanismofpipesaspiratingsteadyfluid,etc.Inparticular,someunresolvedorpartlyresolvedissuesontheseimportantaspectsarediscussed.Finally,thepromisingfuturedevelopmentinthisareaisdiscussed.

简介：Inthispaper,propagationofsoundinpipesundertheinfluenceofagasflowofhightemperatureisinvestigated.Theanalysisinthepa-perisbasedonthefundamentalequationsoffluidmechanics.Approxi-mateformulasofthevariationofparameters,suchasthestatictempera-ture,thelocalvelocityofsound,theflowspeedandtheMachnumber,withdistanceareobtained.Thefourparameterstransmisionmatixwhichdeterminestheacousticalcharacterofthepipeisderivedanddiscussed.Theacousticalcharacterofapulsatinggasheaterisinvestigatedexperim-entallyandtheoretically.Thetheoreticalvaluesoftheresonantfrequenciesofthedeviceareingoodagreementwiththeexperimentalresults.

简介：Accordingtotheresultsofsiteseismichazardanalysisaccomplishedinthepastdecades,96site-relateddesignspectraareselectedassamplesinthisstudy.Theresultshowsthatthevalueofthecornerperiod(Tg)ofthedesignspectruminGBJ11-89(ChinaSeismicBuildingCode,issuedin1989)islowerthanthevalueobtainedbysiteseismichazardanalysis.ThesamesituationexistswhenwecomparethedesignspectraoftheCodestothespectraaccordingtotheearthquakerecords.Thevalueincurrentseismicdesigncode,GBJ50011-2001issuedin2001,isgreaterthanthatinGBJ11-89,butstilllessthanthevalueobtainedbysiteseismichazardanalysis.Ifweacceptthevaluegotbysiteseismichazardanalysis,wehaveasuspicionthat2/3ofbuildingsbuiltaccordingtoGBJ11-89willnotbesafewhenanearthquakewith2%probabilityofexceedancein50yearsoccurs.

简介：Inparticulatematerialtransfersystems,traditionalsheartestbasedsteadystateanalysiscanprovidesomeinsightintothestrengthofthebulkmaterialandsubsequentresistivefrictionalforcesduringflow.Forfastflowingtransferpoints,dynamicflowconditionsdominateandadditionalmodellingtechniquesarerequiredtoimprovedesignguidance.Theresearchpresentedshowstheevolutionofadesignsolutionwhichutilisestwodistinctprocesses;acontinuummethodandadiscreteelementmethod(DEM).Initially,theinternalstructureofdensegranularflow,downverticalandinclinedpipeswasinvestigatedusingatwinsensor,12electrodeelectricalcapacitancetomographydevice.Subsequently,DEMsimulationswereconductedusingthecommercialsoftware,PFC3D.Initially,twoparticletypesandtheirflowbehaviourswereanalysed:plasticpelletsandsand.Thepipeanglewasvariedbetween0°and45°tothevertical.Forboththeplasticpelletsandthesand,goodqualitativeagreementwasfoundwiththespatialparticleconcentrationanalysis.Generally,theflowhadadenseparticleregionatitscorewiththeparticleconcentrationreducingawayfromthiscore.Asexpected,at0°,thecorewascentrallylocatedwithinthepipeforboththeplasticpelletsandsand.Atpipeangles5°orgreater,thedensecoreofparticleswaslocatedonornearthepipewall.Averageflowvelocityanalysiswasalsoconductedusingtheresultsofwallfrictiontestanalysis.ThevelocitycomparisonsalsoshowedgoodagreementbetweentheECTimageanalysisandtheDEMsimulations.Subsequently,theDEMmethodwasusedtoanalyseacomplextransfersystem(orchute)withthecontinuummethodprovidingcomparativeflowanalysiswiththeDEMflowanalysis.

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简介：１ＩｎｔｒｏｄｕｃｔｉｏｎＮＣｌａｙｏｕｔｄｅｓｉｇｎｄｅａｌｓｍａｉｎｌｙｗｉｔｈｔｈｅｍｏｖｅｍｅｎｔｓｔｒｕｃｔｕｒｅａｎｄｔｈｅ３－ｄｉｍｅｎｔｉｏｎａｌｓｐａｔｉａｌａｒｒａｎｇｅｍｅｎｔｏｆｍｏｄｕｌｅｓｉｎＮＣｓｙｓｔｅｍｓ．Ｈｕ［１］...

简介：Oursocietyisdevelopingrapidly,inasocietylikethis,theentrepreneursandproductmanufacturerstendtousewhitespaceorpicturesmassivelyinsteadoftextinformationintheiradvertisementsorleaflets.Thisphenomenonistotallydifferentfromitwasintheyearspast,whenhighpricesandoutdatedtechnologieslimitedthecapabilityofprintingindustry,andforcedthemtoputmoretextinformationintheirpublicationsorprintedmaterials.

简介：High-strengthpipelinesteelandlargediameterlinepipesareoftenusedtoincreasethecapacityoftransportationandreducethecostassociatedwiththeconstructionandoperationoflong-distancegaspipelineprojects.China’sinitiativestoconstructlong-distancenaturalgaspipelineshasbroughtinnewopportunitiesforthedevelopmentofX80linepipes.BaosteelhasdesignedtheoptimumchemicalcompositionofX80withhighniobiumandlowmolybdenumcontent.Inaddition,aweldingexperimentalplatformandafiniteelementmodel(FEM)havesupportedthedevelopmentofX80UOEpipesinanefficientandeconomicalway.TheapplicationandrecentdevelopmentofX80UOEpipeswereintroducedinthispaper.TocomplywiththerequirementsoftheSecondWest-EastGasPipelineProject(2ndWEPP),X80pipelinesteelwithlowcarbonbainitemicrostructurewasdevelopedbyutilizingtheoptimizedcompositionandTMCPprocess.Thematchingweldingmaterial,weldingprocedureandUOEformingprocessesfor1219mmoutsidediameterX80UOEpipeswerealsodeveloped.Morethan340000tofX80UOEpipeswereproducedandappliedinthe2ndWEPP.Furthermore,tomeettheprospectivedemandforlong-distancegaspipelineswithanannualtransportationcapacityofover40billionm3,largersizeX80UOEpipeswith1422mmOD×30.8mmWTweretrialproducedrecently.DWTTperformance,themaintechnicalchallengeforheavierwallpipes,wasimprovedbyusingoptimizedmicrostructuraldesign.ThenewlydevelopedX80pipescanbepotentiallyusedforlargertransportationcapacitypipelinesinChina.

简介：Gatematrixlayoutproblemplaysanimportantroleinintegratedcircuitdesign,butitsoptimizationisNP-hard.Inthispaper,typicalgatelayoutproblemisanalysedandadaptedtoneuralnetworkrepresentation,furthermorethesimulatedresultsaregiven.