简介：一张图的一个顶点被说统治它的邻居的本身和所有。图G的一个双统治集合是G的顶点的集合D，以便G的每个顶点被D的至少二个顶点统治。图G的双支配数字是G的一个双统治集合的最小的集的势。为图G=(V，E)，如果V(G)\D的每个顶点在D有至少二位邻居，子集DV(G)是一个2-dominating集合，当如果，统治G的集合是2-outer-independent的时另外集合V(G)\D是独立的。G的2-outer-independent支配数字是统治G的集合的2-outer-independent的最小的集的势。这份报纸加一个与双支配数字平等者描绘所有树到2-outer-independent支配数字。

简介：Remainingusefullife(RUL)estimationisatopicthathasgainedmoreandmoreattentioninthefieldoffluidpowersystems,thankstothetremendouspotentialsshownforimprovingsafetyandreducedproductionlosses.However,manychallengesrelatedtoRULestimationarenotsolvedyet,mainlyconnectedtothedefinitionofthehealthstatusofeachcomponent.Aprognosticmethodbasedonadata-drivenmethodologyforhydraulicsystemsishereproposedtoestimatethepercentageoflifealreadyspentbythemonitoredcomponents.Thepotentialsofthemethodologyareshownconsideringthecaseofatruck-mountedhydrauliccrane,forwhichasimulationmodelwasavailable.

简介：Polarizationmanipulationisasignificantissueforartificialmodulationoftheelectromagnetic(EM)wave,butgeneralmechanismsallsuffertherestrictionofinherentsymmetricpropertiesbetweenoppositehandedness.Herein,astrategytoindependentlyandarbitrarilymanipulatetheEMwavewithorthogonalcircularpolarizationsbasedonametasurfaceisproposed,whicheffectuallybreaksthroughtraditionalsymmetricalcharacteristicsbetweenorthogonalhandedness.Bysynthesizingthepropagationphaseandgeometricphase,theappropriateJonesmatrixiscalculatedtoobtainindependentwavefrontmanipulationofEMwaveswithoppositecircularpolarizations.Twotransmissiveultra-thinmeta-deflectorsareproposedtodemonstratetheasymmetricalrefractionoftransmittedcircularlypolarizedwavesinthemicrowaveregion.Simulatedtransmittedphasefrontandmeasuredfar-fieldintensitydistributionsareinexcellentagreement,indicatingthatthetransmittedwavewithdifferentpolarizationscanberefractedintoarbitraryandindependentdirectionswithinawidefrequencyband(relativebandwidthof25%).TheresultspresentedinthispaperprovidemorefreedomforthemanipulationofEMwaves,andmotivatetherealizationsofvariouspolarization-independentpropertiesforallfrequencyspectra.

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简介：Wenumericallydemonstrateanovelultra-broadbandpolarization-independentmetamaterialperfectabsorberinthevisibleandnear-infraredregioninvolvingthephase-changematerialGe2Sb2Te5（GST）.Thenovelperfectabsorberschemeconsistsofanarrayofhigh-indexstrong-absorbanceGSTsquareresonatorsseparatedfromacontinuousAusubstratebyalow-indexlosslessdielectriclayer（silica）andahigh-indexGSTplanarcavity.Threeabsorptionpeakswiththemaximalabsorbanceupto99.94%areachieved,owingtotheexcitationofplasmon-likedipolarorquadrupoleresonancesfromthehigh-indexGSTresonatorsandcavityresonancesgeneratedbytheGSTplanarcavity.Theintensitiesandpositionsoftheabsorptionpeaksshowstrongdependenceonstructuralparameters.AheattransfermodelisusedtoinvestigatethetemporalvariationoftemperaturewithintheGSTregion.TheresultsshowthatthetemperatureofamorphousGSTcanreachupto433Kofthephasetransitiontemperaturefromroomtemperatureinjust0.37nswitharelativelylowincidentlightintensityof1.11×108W∕m2,duetotheenhancedultra-broadbandlightabsorbancethroughstrongplasmonresonancesandcavityresonanceintheabsorber.Thestudysuggestsafeasiblemeanstolowerthepowerrequirementsforphotonicdevicesbasedonathermalphasechangeviaengineeringultra-broadbandlightabsorbers.