简介：Tosystematicallystudythevehicle–bridgecoupleddynamicresponseanditschangerulewithdifferentparameters,avehiclemodelwithsevendegreesoffreedomwasbuiltandthetotalpotentialenergyofvehiclespacevibrationsystemwasdeduced.Consideringthestimulationofroadroughness,thedynamicresponseequationofvehicle–bridgecoupledsystemwasestablishedinaccordancewiththeelasticsystemprincipleoftotalpotentialenergywithstationaryvalueandthe‘‘set-in-right-position''rule.Onthebasisoftheself-compiledFortranprogramandbridgeengineering,thedynamicresponseoflongspancontinuousgirderbridgeundervehicleloadwasstudied.Thisstudyalsoincludedthecalculationofvehicleimpactcoefficient,evaluationofvibrationcomfort,andanalysisofdynamicresponseparameters.Resultsshowtheimpactcoefficientchangeswithlanenumberandislargerthanthevaluecalculatedbythe‘‘generalcodefordesignofhighwaybridgesandculverts(China)''.TheDieckmannindexofbridgevibrationisalsorelatedtolanenumber,andthevibrationcomfortevaluationisgoodinnormalconditions.Therelevantconclusionsfromparametricanalyseshavepracticalsignificancetodynamicdesignanddailyoperationoflong-spancontinuousgirderbridgesinexpressways.Safetyandcomfortareexpectedtoimprovesignificantlywithfurthercontrolofthevibrationofvehicle–bridgesystem.

简介：A3DfiniteelementmodelfortheTaizhouYangtzeRiverBridge,thefirsttriple-towerlong-spansuspensionbridgeinChina,isestablishedbasedonthenonlinearfiniteelementsoftwareABAQUS,andthedynamiccharacteristicsofthebridgeareanalyzedusingtheLANCZOSeigenvaluesolutionmethod.Thestudyfocusesontheeffectsofthevertical,lateralandtorsionalstiffnessofthesteelboxgirder,therigidcentralbuckleandtheelasticrestraintsconnectingthetowersandthesteelboxgirderonthedynamiccharacteristicsofthetriple-towersuspensionbridge.Ourresultsshowthat,ingeneral,thedynamiccharacteristicsofthetriple-towersuspensionbridgearesimilartothoseoftwo-towersuspensionbridges.Thevertical,lateralandtorsionalstiffnessofthesteelboxgirderhavedifferenteffectsonthedynamiccharacteristicsoftriple-towersuspensionbridges.Theelasticre-straintshaveamoresignificanteffectonthedynamiccharacteristicsthanthecentralbuckle,anddecreasingthestiffnessoftheelasticrestraintsresultsintheappearanceofalongitudinalfloatingvibrationmodeofthebridge.Also,rigidcentralbuckleshaveagreaterinfluenceonthedynamiccharacteristicsoftriple-towersuspensionbridgesthanonthoseoftwo-towersuspensionbridges.Theresultsobtainedcouldserveasavaluablenumericalreferenceforanalyzinganddesigningsuper-long-spantriple-towersuspensionbridges.

简介：Considerthemotionofimmersedhypersurfacesdrivenbysurfacediffusionflowandgiveanlowerboundonthelifespanofasmoothimmersedsolution,whichdependsonlyonhowmuchthecurvatureoftheinitialsurfaceisconcentratedinspace.

简介：ThispaperdealswiththeCauchyproblemforadoublysingularparabolicequationwithaweightedsource■whereN≥1,1max{0,3-p-p/N}satisfying21,andα>N(3-p-m)-p.Wegivethesecondarycriticalexponentonthedecayasymptoticbehaviorofaninitialvalueatinfinityfortheexistenceandnon-existenceofglobalsolutionsoftheCauchyproblem.Moreover,thelifespanofsolutionsisalsostudied.更多还原

简介：Theauthorconsidersthelife-spanofclassicalsolutionstoCauchyproblemforgeneralfirstorderquasilinearstrictlyhyperbolicsystemsintwoindependentvariableswith"slow"decayinitialdata.Byconstructinganexample,firstitisillustratedthattheclassicalsolutiontothiskindofCauchyproblemmayblowupinafinitetime,evenifthesystemisweaklylinearlydegenerate.Thensomelowerboundsofthelife-spanofclassicalsolutionsaregiveninthecasethatthesystemisweaklylinearlydegenerate.Theseestimatesimplythat,whenthesystemisweaklylinearlydegenerate,theclassicalsolutionexistsalmostgloballyintime.Finally,itisprovedthatTheorems1.1-1.3in[2]arestillvalidforthiskindofinitialdata.

简介：Thenecessitytodistributethedataoverthewideareanetwork(WAN)tothephysicists'homeinstituteswillincrease,andtheeffectiveutilizationofthenetworkbecomescrucial,However,networksinthefutureWANwilltypicallyhavealargebandwidthatanorderofgigabitpersecond,withalatencyofseveralhundredssecondssothatthelargebandwidth-delayprodeuctextendstotensofmegabytesandnumerousproblemsareencountered.suchnetworksarecalled"longfatnetworks(LFNs)"Inordertostudythedatatransferoperatingonalongfatnetwork,wehavebuiltthePCclustersconnectedwiththerouterwhichcansimulatebandwidthlimitations.delays,packetlosses,andmultipatheffects.thisrouterisrunningonFreeBSDwithDUMMYNETkerneloption.Onthesemachineswehavemeasuredtheperformanceofthebulkdatatransfterwithnumerousconditionsandstudiedtheeffecienttransftermethods.

简介：Inthispaper,westudytheasymptoticCUSUMtestsfordetectingchangesinthemeanorvarianceofamoving-averageprocesswithlongmemory.Whenthereisnochangeover[O,T],theasymptoticdistributionoftheteststatisticisderived,whichallowsustofindasymptoticcriticalvalues.Whenthereisachange,thebehavioroftheteststatisticisdiscussed.Conditionsfortheconsistencyofthesetestsarealsodiscussed.Basedontheasymptoticresults,simulationstudiesoftestingforchangesinthemeanshowthattheCUSUMtestproposedperformswell.

简介：Inthispaper,twofinitedifferenceschemesarepresentedforinitial-boundaryvalueproblemsofRegularizedLong-Wave(RLW)equation.Theyallhavetheadvantagesthattherearediscreteenergieswhichareconserved.ConvergenceandstabilityofdifferencesolutionswithorderO(h2+τ2)areprovedintheenergynorm.Numericalexperimentresultsdemonstratetheeffectivenessoftheproposedschemes.

简介：Bisphenolscontaininglongaliphatichydrocarbonsidechainsweresynthesizedbythecondensationofphenolwithaldehydeorketoneinthepresenceofheteropolyacid.TheirstructureswerecharacterizedbyIR,1HNMR,13CNMRandelementanalysis.Theexperimentresultsshowthatwhenheteropolyacidwasusedasacatalyst,thesebisphenolswereobtainedinhighselectivityandhighyields.

简介：ThelongtermaccessibilityofitsdataisanimportantconcernoftheDELPHIcollaboration.Itisourassumptionthatthestorageofthedataitselfwillbeaminorissueduetotheprogressinstoragetechnologies.ThereforeDELPHIfocusesonareorganisationofthedata,whichshouldprovideaflexibleandcoherentframeworkforphysicsanalysisinthefuture.ThispaperdescribesthecurrentstatusoftheIDEA(ImprovedDElphiAnalysis)projectwhichwillensureusabilityofDELPHIdataforfuturegenerationsofphysicists.

简介：<正>Supposethat{αk}k∞=-∞isaLacunarysequenceofpositivenumberssatisfyinginfαk+1/αk=α>1andthatΩ（y’）isafunctionintheBesovspaceB10,1(Sn-1)whereSn-1istheunitsphereonRn（n≥2）.Weprovethatif∫Sn-1Ω（y’）dσ（y’）=0thenthediscretesingularintegraloperatorTΩf（x）=∫(Sn-1)f（x-αky’）Ω（y’）dσ（y’）andtheassociatedmaximaloperatorTΩf（x）=∫Sn-1f（x-αky’）Ω（y’）dσ（y’）arebothboundedinthespaceL2（Rn）.ThetheoremsinthispaperimprovearesultbyDuoandikoetxeaandRubiodeFranciaintheL2case.

简介：Thispaperpresentsameshlessmethodforthenonlineargeneralizedregularizedlongwave(GRLW)equationbasedonthemovingleast-squaresapproximation.ThenonlineardiscreteschemeoftheGRLWequationisobtainedandissolvedusingtheiterationmethod.Atheoremontheconvergenceoftheiterativeprocessispresentedandprovedusingtheoremsoftheinfinitynorm.Comparedwithnumericalmethodsbasedonmesh,themeshlessmethodfortheGRLWequationonlyrequiresthescatterednodesinsteadofmeshingthedomainoftheproblem.Someexamples,suchasthepropagationofsinglesolitonandtheinteractionoftwosolitarywaves,aregiventoshowtheeffectivenessofthemeshlessmethod.

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简介：Longpilesoftheoceanoilplatformareusuallymanufacturedastheintegrationofseveralsegments,whichhavetobeassembledonebyoneduringinstallation.Duringpiledriving,excessiveporepressurewillbuildupinsuchahighlevelthathydraulicfracturinginthesoilroundthepilemaytakeplace,whichwillcausethesoiltoconsolidatemuchfasterduringpileextensionperiod.Consequently,afterpileextension,thesoilstrengthwillrecovertosomeextentandthedrivingresistancewillincreaseconsiderably,whichmakesrestartingdrivingthepileverydifficultandevencausesrefusal.Afiniteelement(FE)analysisprocedureispresentedforjudgingtheriskofrefusalbyestimatingtheblowcountsafterpileextension,inwhichtheregainofsoilstrengthisconsidered.AcaseanalysisinBohaiGulfisperformedusingtheproposedproceduretoexplainthepilerefusalphenomenon.

简介：Amethodforinertialconfinementfusiondrivenbypowerfullongwavelengthelectromagneticpulses(EMPs),suchasCO2laserpulsesorhighpowermicrowavepulses,isproposed.Duetothehighefficiencyofgeneratingsuchlongwavelengthelectromagneticpulses,thismethodisespeciallyimportantforthefuturefusionelectricitypower.Specialfueltargetsaredesignedtoovercometheshortcomingsofthelongwavelengthelectromagneticpulses.

简介：Basedonanewdefinitionofnonlocalvariable,thispaperestablishestheLagrangianformulationforcontinuumwithinternallong-rangeinteractions.Distinguishedfromtheexistingtheories,thenonlocaltermintheLagrangianformulationautomaticallysatisfiesthezeromeanconditiondeterminedbytheactionandreactionlaw.Bythisformulation,elasticwaveinarodwiththeinternallong-rangeinteractionsisinvestigated.Thedispersionoftheelasticwaveispredicted.

简介：Usingultrasonicguidedwavestoassesslongbonefracturesandfracturehealinghasbecomeapromisingdiagnosticissue.Butthemultimodeoverlapoftheguidedwaveschallengesthequantitativeevaluationandclinicalapplication.Inthepreformedstudy,inordertosimplifythesignalinterpretation,thelow-frequencysinusoidialsignalswereusedtoonlyexciteS0andA0modesinfracturedlongbones.TheamplitudesofS0andA0modeswerenumericallyanalyzedwithvariationincrackwidthandfractureangle.Numericalsimulation,basedonthetwo-dimensionfinite-differencetime-domain(2D-FDTD)revealsthatbothS0andA0amplitudesdecreasewiththefracturewidening.However,theincreaseinfractureanglegraduallyenhancestheA0amplitude,whilewithrespecttotheS0mode,itsamplitudeshowsanon-monotonictrendtothevariationinfractureanglewithaturningpointaround45°.TheamplituderatiobetweenS0andA0canreflectthevariationsincrackwidthandfractureangles.ThesimulationillustratesthatultrasonicguidedS0andA0modesaresensitivetothedegreeofbothverticalandobliquefracturesinthelongcorticalbone.Thesefindingsmaybehelpfulforfracturesdiagnosisandhealingevaluationofthelongbone.

简介：ForagraphG,wedenotebyp(G)andc(G)thenumberofverticesofalongestpathandalongestcycleinG,respectively.ForavertexvinG,id(v)denotestheimplicitdegreeofv.Inthispaper,weobtainthatifGisa2-connectedgraphonnverticessuchthattheimplicitdegreesumofanythreeindependentverticesisatleastn+1,theneitherGcontainsahamiltonianpath,orc(G)≥p(G)-1.

简介：Aso-called“localprobabilisticParisrelationmethod”waspresentedformeasuringtherandomthresholdsoflongfatiguecrackpropagation.Acheckwasmadetotheconventionalmethod,inwhichthethresholdsweremeasuredstatisticallyanddirectlybythetestdata.Itwasrevealedthatthismethodwasnotreasonablebecausethetestdatahaveseldomaunifiedlevelofcrackgrowthrates.Differently,inthepresentedmethodtheParis-Erdoganequationwasappliedtomodelthelocaltestdataaroundthethresholds.Localprobabilisticrelationswithboththesurvivalprobabilityandtheconfidencewereestablishedonalognormaldistributionofthestressdensityfactors.Andthen,theprobabilisticthresholdswerederivedfromtheprobabilisticfactorswithagivencriticallevelofgrowthrate.AnanalysisonthetestdataofLZ50axlesteelfortheChineserailwayvehiclesverifiesthatthepresentmethodisfeasibleandavailable.

简介：LongtimebehaviorofdegenerateequationswiththenonlinearityofpolynomialgrowthofarbitraryorderonthewholespaceRNisconsidered.Byusing-trajectoriesmethods,weprovedthatweaksolutionsgeneratedbydegenerateequationspossessan(L2U(RN),L2loc(RN))-globalattractor.Moreover,theupperboundsoftheKolmogorovε-entropyforsuchglobalattractorarealsoobtained.