简介：Permanentmagnetscapableofreliablyoperatingathightemperaturesupto450?Carerequiredinadvancedpowersystemsforfutureaircrafts,vehicles,andships.ThoseoperatingtemperaturesarefarbeyondthecapabilityofNd–Fe–Bmagnets.PossessinghighCurietemperature,Sm–Cobasedmagnetsarestillveryimportantbecauseoftheirhightemperaturecapability,excellentthermalstability,andbettercorrosionresistance.Theextensiveresearchperformedaroundtheyear2000resultedinanewclassofSm2(Co,Fe,Cu,Zr)17-typemagnetscapableofoperatingathightemperaturesupto550?C.ThispapergivesasystematicreviewofthedevelopmentofSm–Copermanentmagnets,fromthecrystalstructuresandphasediagramstotheintrinsicmagneticproperties.AnemphasisisplacedonSm2(Co,Fe,Cu,Zr)17-typemagnetsforoperationattemperaturesfrom300?Cto550?C.Thethermalstabilityissues,includinginstantaneoustemperaturecoefficientsofmagneticproperties,arediscussedindetail.Thesignificanceofnanograinstructure,nanocrystalline,andnanocompositeSm–Comagnetmaterials,andprospectsoffuturerare-earthpermanentmagnetsarealsogiven.

简介：Inthispaper,aone-dimensionparticle-in-cell(PIC)code(EDIPIC)isemployedtosimulatetheparallel-plateionextractionprocessunderanexternallyappliedelectrostaticfield,focusingontheanalysisoftheinflueneeoftheinitialelectrontemperatureontheextractedionfluxestothemetalplatesduringtheionextractionprocess.Comparedwithpreviouslypublishedresults,theplasmaoscillationsonatimescaleoftheelectronplasmaperiod,andtheexcitationoftheionacousticrarefactionwavesresultingfromtheplasmaoscillationsoriginatingfromboththenegativeandpositiveelectrodes,arestudiedforthefirsttime.Themodelingresultsshowthatboththenegativeandpositiveextractorscancollectionsduetotheplasmaoscillationsandthepropagationoftheionacousticrarefactionwaves.Withtheincreaseoftheinitialelectrontemperatureachievedbykeepingotherparametersunchanged,ontheonehand,boththeionspeedandfluxtothenegativeandpositiveplatesincrease,whichleadstoasignificantdecreaseoftheionextractiontime,whileontheotherhand,theionfluxtothepositiveplateaftertheformationofaChild-Langmuirsheathismuchmoresensitivetoanincreaseoftheinitialelectrontemperaturethanthattothenegativeplate.ThePICsimulationresultsprovideadeeperphysicalunderstandingoftheinfluenceoftheinitialelectrontemperatureonthecharacteristicsoftheentireionextractionprocessinadecayingplasma.

简介：Inrecentyears,mteractingtopologicalinsulatorshaveemergedasnewfrontiersincondensedmatterphysics,andthehotlystudiedtopologicalKondoinsulator(TKI)isoneofsuchprototypes.Althoughitszero-temperatureground-statehasbeenwidelyinvestigated,thefinitetemperaturephysicsonTKIislargelyunknown.Here,weexplorethefinitetemperaturepropertiesinasimplifiedmodelforTKI.namelytheone-dimensionalp-waveperiodicAndersonmodel,withnumericallyexactdeterminantquantumMonteCarlosimulation.ItisfoundthatthetopologicalHaldanephaseestablishedforgroimdstateisstillstableagainstsmallthermalfluctuationanditscharacteristicedgemagnetizationdevelopsatlowtemperature.Suchfactsemphasizetherobustnessof(symmetry-protected)topologicalorderagainsttemperatureeffect,whichalwaysexistsatrealphysicalworld.Moreover,weusethesaturatedlow-Tspinstructurefactorandthe1/T-lawofsusceptibilitytodetectthefreeedgespinmoment,interestinglythelow-temperatureupturnbehaxiorofthelatteroneissimilartoexperimentalfindinginSniBgatT<50K.Itimpliesthatsimilarphysicalmechanismmayworkbothforidealizedmodelsandrealisticcorrelatedelectronmaterials.WehavealsoidentifiedanemergentenergyscaleTcr.whichsignalsacrossoverintointerestinglow-TregimeandseemstobetheexpectedRuderman-Kittel-KasuyaYosidacoupling.Finally,thecollectiveKondoscreeningeffecthasbeenexaminedanditisheavilyreducedatboundarywhichmaygiveafruitfulplaygroundfornovelphysicsbeyondthewellestablishedHaldanephaseandtopologicalbandinsulators.

简介：OnSeptember19,2018,the100kt/acommercialdemonstrationhigh-temperatureFischer-Tropschsynthesisunit,constructedbytheShaanxiFutureEnergyChemicalCompany,Ltd.(FECC),cameonstreamsuccessfullyatthefirstattemptandhadbeenoperatingcontinuouslyandsmoothlyfor168hoursatfullload.ItistoldthatthisisthefirstcommercialdemonstrationhightemperatureFischer-TropschsynthesisunitbuiltinChinawithcompletelyindependentintellectualpropertyrights.Thecommissioningofthisdemonstrationunitevidencesthatthehigh-temperatureFischer-Tropschsynthesistechnologyhasfullymettheindustrializationconditions.

简介：TheSiO2nanoparticleswerecoatedonthesurfaceofgrapheneoxide(GO)bysol-gelmethodtogettheSiO2-Gcompound.TheSiO2-GwasrestoredandoleophylicallymodifiedtopreparehydrophobicmodifiedSiO2-G(HM-SiO2-G)whichwassubsequentlyaddedtosiliconerubbermatrixtopreparetwo-componentroomtemperaturevulcanized(RTV-2)thermalconductivesiliconerubber.Themorphology,chemicalstructureanddispersityofthemodifiedgraphenewerecharacterizedwithSEM,FTIR,Raman,andXPSmethods.Inaddition,theheat-resistancebehavior,mechanicalproperties,thermalconductivity,andelectricalconductivityoftheRTV-2siliconerubberwerealsostudiedsystematically.TheresultsshowedthattheSiO2nanoparticleswerecoatedongrapheneoxidesuccessfully,andHM-SiO2-GwasuniformlydispersedinRTV-2siliconerubber.TheadditionofHM-SiO2-Gcouldeffectivelyimprovethethermalstability,mechanicalpropertiesandthermalconductivityofRTV-2siliconerubberandhadnogreatinfluenceontheelectricalinsulationperformance.