简介：Magneticforcetransmissionofareciprocatingmotionisstudiedbytheoreticalanalysisandexperiment.Amathematicalmodelforcalculatingthemagneticforceisderivedusingthetheoryofequivalentmagneticcharges.Anexperimentalrigisconstructedtotestthetransmissionandthemodelisverifiedbyexperiment.Effectofthetransmissionparametersonthemagneticforceisanalyzedtheoreticallyfromthemodel,andcharacteristicofthetransmissionisstudiedexperimentally.Sincethetransmissioniswithoutdirectcontactbetweentwoelements,itissuitableforapplicationinanorganism.

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简介：Themechanismsofmagnetoreceptionhavebeenproposedasthemagnetitebased,thechemicalradical-pairandbiocompassmodel,inwhichmagnetiteparticles,thecryptochrome(Cry)oriron-sulfurclusterassembly1(IscA1)maybeinvolved.However,littleisknownabouttheassociationamongthemolecules.HereweinvestigatedthemolecularcharacterizationandthemRNAexpressionofIscA1indifferentdevelopmentalstages,tissuesandmagneticfieldsinthemigratorybrownplanthopper(BPH),Nilaparvatalugens.NlIscA1containsanopenreadingframeof390bp,encodingaminoacidsof129,withthepredictedmolecularweightof14.0kDaandtheisoelectricpointof9.10.Well-conservedFe-Sclusterbindingsiteswereobservedinthepredictedprotein.PhylogeneticanalysisdemonstratedNlIscA1tobeclusteredintotheinsect'sIscA1.NlIscA1showedup-regulatedmRNAexpressionduringtheperiodofmigration.ThemRNAexpressionofNlIscA1couldbedetectedinallthethreetissuesofhead,thoraxandabdomen,withthehighestexpressionlevelintheabdomen.ForthemacropterousmigratoryNilaparvatalugens,mRNAexpressionofNlIscA1andN.lugenscryptochromel(Nlcry1)wereup-regulatedunderthemagneticfieldsof5Gaussand10Gaussinstrength(vs.localgeomagneticfield),whileN.lugenscryptochrome2(Nlcry2)remainedstable.Forthebrachyterousnon-migratoryNilaparvatalugens,nosignificantchangeswerefoundinmRNAexpressionofNlIscA1,Nlcry1andNlcry2amongdifferentmagneticfields.ThesefindingspreliminarilyrevealthattheexpressionofNlIscA1andNlcry1exhibitedcoordinatedresponsestothemagneticfield.Itsuggestssomepotentialassociationsamongtheputativemagneto-sensitivemoleculesofcryptochromeandiron-sulfurclusterassembly.