简介:BasedontheABAQUSexplicitdynamicsimulationplatform,thefiniteelementmodelofsinglestandmillwithrestrainedmandrelwasadoptedtoresearchtheinfluenceofmandrel-rollervelocityratio(MRVR),mandrelfrictionandtensionbetweenstandsonrollingforce.TheanalysisresultsshowthatwhentheMRVRislowerthan1,therollingforceincreasesobviouslywiththeincreaseofMRVRandreachesthepeakvaluewhentheMRVRisabout1.TherollingforceincreaseinducedbytheMRVRincreaseisthemainreasonoftheformationofthebulgedefectonthetubeheadandtailattheenteringandexitingstageduringtubecontinuousrollingprocessbyfullfloatingmandrelmill,whichcanbeintensifiedbytheincreaseofmandrelfrictioncoefficient.Therollingforcedecreaseswiththeincreaseoftension.Asthetensionislarger,therollingforcedecreaseamplitudeislarger.Theinfluenceofbackwardtensiononrollingforceisgreaterthanthatofforwardtensiondistinctly.TensioncontrolcanbeusedtodecreasetherollingforceincreaseinducedbytheMRVRincrease,whichisimposingtensionatthesametimewhentheMRVRincreases,inordertoimproveeveneliminatethebulgedefect,andenhancethetubedimensionprecision.
简介:Themorphologyandtheevolutionofδ-ferriteexistinginB410Dslabs,hot-rolledplates,annealedplatesandquenchedplateswerestudiedthroughmetallographicobservation.Resultsshowthatδ-ferriteformsduringthesolidificationprocessandthatiteasilygrowsandincreasesinquantityduringhightemperatureannealing.Band-shapedδ-ferriteinhotrolledplatesisdifficulttobeeliminatedbyconventionalheattreatmentandhardtorecrystallize.
简介:Lanthanumchlorideα-D-ribopyranosepentahydratecomplexwaspreparedandspeculateditsstructurefromthesimilarIRspectraofcorrespondingpraseodymiumandneodymium-D-ribosecomplexes,whichrevealthecoordinationbehaviorofD-ribosetolanthanideionsandgiveusamodeloftheinteractionsbetweenmetalionsandcarbohydrates.
简介:Athree-dimensionalmathematicalmodelofthecombustionofpulverizedcoalandcokehasbeendeveloped.Themodelisappliedtotheblowpipe-tuyere-raceway-cokebedregioninanironmakingblastfurnaceinonecomputationaldomain,whichincludestwoparts:pulverizedcoalcombustionmodelintheblowpipe-tuyere-racewaycavityandthecoal/cokecombustionmodelinthesurroundingcokebed.Theeffectsofcoalpropertiesareexaminedcomprehensively,intermsofcoalburnoutandgasspeciesdistributions.TheresultsindicatethatusingacoaloffineparticlesizeorhighVMcontentcouldimproveburnoutandwouldaffectthegascompositionconsiderably.Theburnoutisexaminedintwoways:comparedwithburnoutalongtuyereaxis,burnoutovertheracewaysurfaceisamoresensitiveandsensibleparametertodescribetheamountofunburntcharenteringthecokebed.Themodelisusefulforexaminingtheflow-thermo-chemicalcharacteristicsofthepulverizedcoalinjection(PCI)processundervariousconditionsinablastfurnace.
简介:Thesimplemodelfor4f-5dtransitionsoflanthanideionsincrystalswasextendedtodealwiththecaseoftheoctahedralcrystalfield,whereforthet2componentof5dorbitalsthespin-orbitinteractioncouldnotbeneglectedduetoincompletequenchingofthe5dorbitalangularmomentum.Theenergylevelsforthe4fN-15dconfigurationandtherelativelinestrengthsforthe4fN4fN-15dtransitionwerecalculatedindetail.Theresultwasappliedtotheinterpretationofthelow-temperature4f-5dexcitationspectrumofCs2NaYCl6∶Tb3+.