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264Vol.26,No.4200512JournalofHebeiUniversityofScienceandTechnologyDec.2005:100821542(2005)0420330204,(,100044):,11.0105gNdFeB,NdFeB,,:;;;:U237;U260133+12:AStudyoftheequipmentofthediamagneticbearingsWANGGui2xiang,FANYu(SchoolofElectricalEngineering,BeijingJiaotongUniversity,Beijing100044,China)Abstract:Weapplydiamagneticmaterialstothemagneticbearings,usingexperimentalapparatustostudythestaticequilibri2um,load2carryingcapacityanddynamiccharacteristicsofthebearings.Theapparatusconsistsofa1.0105gNdFeBcolumnper2manent2magnetrotor,andaNdFeBliftmagnettolevitatetherotorandadiamagneticgraphite.Weusefiniteelementmethodandtheanalyticformulatocalculatethebearings2load,andtheresultisconsistent.Keywords:diamagnetic;magneticlevitation;bearings;stabilization,[1,2][3,4],,,1,(6119,Earnshaw)[5],,,,,,,,,1,,,:2005206216;:2005209229;::(20030004013):(19742),,,,1Fig.1Frameofthebearings,,,,,1NdFeB,35mm16mmN38H,1.265T;6mm2.8mmN35H,1.0105g,1.235T,-0.0000017,ansoft,[3],,,,,matlab,0.00016N,,,2MB:F=(M¨)B,II1[3]F=0II11-1J(1-vsgn(v))dv,(1):J=1-k2(1-0.5k21-k2E(k)-K(k)),K=/2011-k2sin2d,E=/201-k2sin2d,k=11+r2,r=dR+L2R(1+v),d,RL;I=MR2[6];I1=M1R21(1)2,2Fig.2Relationofthemagneticforceandthedistanceofthemagnet,,[6]I=r-1r+1=I2,Bir[3]Bir=30Mr8r4i=30Mr8D4,:D;Mr:F=2RBir=3M2||04D4(2)(2)D313344,(3),,(2),[3]12B0(mgM)2B2CzM,12B0(mgM)2B120M||D5,D(120M||B)1/5(240B0M3||(mg)2)1/5(3)(3),Cz,,m,0,410-7,B0D/26.2mm45Fig.5Ievitatingmagneticbearing35mm16mmNdFe38,6mm4.8mmNdFe35,(,,)5,,1.0105g,(3),(3)D6.2mm,6mm,6.2mmAnsoft,,,,2332005,,:[1]GEIMAK,SIMONMD,BOAMFAMI,etal.Magnetlevitationonyourfingertips[J].Nature,1999,400:3232324.[2]SIMONMD,GEIMAK.Diamagneticlevitation:Flyingfrogsandfloatingmagnets[J].JApplPhys,2000,87:620026204.[3]SIMONMD,HEFLINGERLO,GEIMAK.Diamagneticallystabilizedmagnetlevitation,Amer[J].JPhys,2001,69:7022713.[4]BEAUGNONE,TOUMIERR.Levitationoforganicmaterials[J].Nature,1991,339:470.[5]EARNSHAWS.Onthenatureofthemolecularforces,whichregulatetheconstitutionoftheluminiferousether[J].TransactionsofCam2bridgePhilosophicalSociety,1842,7:972112.[6]SMYTHEWR.StaticandDynamicElectricity[M].NewYork:HemispherePublishingCorporation,1989.306.(276)2.26,,3,2,,1.2,1.3,22Tab.2Recovery/%/%RSD/%96.1499.61105.2100.34.695.2398.79104.899.614.8p,p’2DDE94.27106.596.8299.206.5p,p’2DDD95.60104.197.7399.144.5o,p’2DDT94.2599.5495.0196.273.0p,p’2DDT93.4397.20101.997.514.4:1.67ng/g;:8.33ng/g;:16.7ng/g2.32,1.21.3,,2,33(ng/g)Tab.3Determinationresultsofpesticidesinpaeonialactiflrapallpallp,p’2DDEp,p’2DDDo,p’2DDTp,p’2DDT15.7410.39922.554NDNDND230.9911.229.76012.855.9648.137ND1HEPT;2HCE;3p,p’2DDE;4p,p’2DDD;5o,p’2DDT;6p,p’2DDT2Fig.2Chromatogramofpaeonialactiflrapall3,,,:[1],,.[J].,1998,29(6):3812384.[2],.[J].,1994,22(9):9312934.[3],,,.20[J].,2000,18(4):3462349.[4],.[J].,1998,13(3):48250.[5],,,.[J].,1999,18(6):79283.[6],,,1[J].,1996,21(10):59125931[7],1[J]1,2004,21(5):56259.3334