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简介：Quantumcomputingrequiresultracoldionsinagroundvibrationalstate,whichisachievedbysidebandcooling.WereportourrecenteffortstowardstheLamb-Dickeregimewhichisaprerequisiteofsidebandcooling.Wefirstanalysethepossibleimperfectioninourlineariontrapsetupandthendemonstratehowtosuppresstheimperfectionbycompensatingtheexcessmicromotionoftheions.Theions,afterthemicromotioncompensation,areestimatedtobeveryclosetotheDoppler-coolinglimit.

简介：Commerciallyavailablelatticescontainvariouskindsofmorphologicalimperfectionswhichresultingreatdegradationinlattices’mechanicalproperties,therefore,toobtainimperfectioninsensitivelatticestructureisobviouslyapracticalresearchsubject.Hierarchicalstructurematerialswerefoundtobeaclassofpromisinganti-defectmaterials.Thispaperbuildshierarchicallatticebyaddingsoftadhesiontolattice’scelledgesandnumericalresultsshowthatitsimperfectionsensitivitytomissingbarsisminorcomparedwiththeclassiclattice.Softadhesionwithappropriatepropertiesreinforcecelledge’sbendingstiffnessandthusreducethebendingdeformationinlatticecausedbymissingbarsdefect,whichisconfirmedbystatisticalanalysisofnormalizednodedisplacementsofimperfectlatticesunderhydrostaticcompressionandshearloads.

简介：Aprobabilistieprogressivefailureanalyzingmethodisappliedtoestimatingthereliabilityofasimplysupportedlaminatedeompositeplatewithaninitialimperfectionunderbi-axialeompressionload.Theinitialimperfectionandthestrengthparametersareconsideredasrandomvariables.Ply-levelfailureproba-bilityisevaluatedbythefirstorderreliabilitymethod(FORM)togetherwiththeTsai-WustrengtheriterionandTancriterion.Currentstressesinthelaminatedstructurearecalculatedbytheclassicallaminationtheorywiththestiffnessmodifiedbasedonthelaststepplyfailure.Probabilistieallydominantply-levelfailurese-quencesleadingtooverallsystemfailureareidentified,basedonwhichthesystemfailureprobabilityisesti-mated.Anumeriealexampleispresentedtodemonstratethemethodologyproposed.Throughparameterstud-iesitisshownthatthedeviationoftheinitialimperfeetionandsomeofthestrengthparameterslargelyinflu-encethesystemreliability.

简介：Thisstudyinvestigatedcharacteristicsofbifurcationandcriticalbucklingloadbyshapeimperfectionofspacetruss,whichweresensitivetoinitialconditions.Thecriticalpointandbucklingloadwerecomputedbytheanalysisoftheeigenvaluesanddeterminantsofthetangentialstiffnessmatrix.Thetwo-free-nodesexampleandstardomewereselectedforthecasestudyinordertoexaminethenodalbucklingandglobalbucklingbythesensitivitytotheeigenbucklingmodeandtheanalysesoftheinfluence,andcharacteristicsoftheparametersasdefinedbytheloadratioofthecenternodeandsurroundingnode,aswellasrise-spanratiowereperformed.Thesensitivitytotheimperfectionoftheinitialshapeofthetwo-free-nodesexample,whichoccursduetosnappingatthecriticalpoint,resultedinbifurcationbeforethelimitpointduetothebucklingmode,andthebucklingloadwasreducedbytheincreaseintheamountofimperfection.Thetwosensitivebucklingpatternsofthenumericalmodelareestablishedbyinvestigatingthedisplacedpositionofthefreenodes,andtheasymmetriceigenmodegreatlyinfluencedthebehavioroftheimperfectionshapewhetheritwasatlimitpointorbifurcation.Furthermore,thesensitivemodeofthetwo-free-nodesexamplewassimilartothein-extensionalbasismechanismofasimplifiedmodel.Thestardome,whichwasusedtoexaminetheinfluenceamongseveralnodes,indicatedthattheinfluenceofnodalbucklingwasgreaterthanthatofglobalbucklingastherise-spanratiowashigher.Besides,globalbucklingisoccurredwithreachingbifurcationpointasthevalueofloadratiowashigher,andthebucklingloadlevelwasabout50%-70%ofloadlevelatlimitpoint.