简介：Inthispaper,atheoreticalformulaispresentedtopredicttheinstantaneousfoldingforceofthefirstfoldcreationinsquareandrectangularcolumnsunderaxialloading.Therectangularcolumnisasmallandsinglemodelofhoneycombswithsquareorrectangularcells.CalculationsarebasedontheanalysisoftheBasicFoldingMechanism(BFM).Forthispurpose,sumofthedissipatedenergyrateunderbendingaroundhorizontalandinclinedhingelinesandthedissipatedenergyrateunderextensionaldeformationswasequaltotheworkrateoftheexternalforceonthestructure.Thefinalformulaobtainedinthisresearch,reasonablypredictstheinstantaneousfoldingforceofsingle-cellsquareandrectangularhoneycombsinsteadoftheaveragevalue.Finally,accordingtothecalculatedtheoreticalrelation,theinstantaneousfoldingforceofthefirstfoldcreationinasquarecolumnwassketchedversusfoldingdistanceandcomparedtotheexperimentalresults,whichshowedagoodcorrelation.

简介：Inthispaper,theobtainedexperimentalresultsconcerningcreationofbulkelementaryexcitations(BEEs)iniso-topicallypureliquid4Heatlowtemperatures~60mKarediscussed.Positiverotons’(R+-rotons)creationbyapulsedheaterwasstudied.Signalswererecordedforthefollowingquantumprocesses:quantumevaporationof4He-atomsfromthefreeliq-uid-heliumsurfacebytheBEEsoftheliquidhelium-II,andBEEsreflectionfromthefreesurfacebackintothebulkliquid.Typicalsignalsareshown,andratiosofsignalamplitudesareevaluated.Forlongheaterpulsesfrom5to10μs,appearanceofthesecondatomiccloudconsistingofevaporated4He-atomswasobservedinadditiontothefirstatomiccloud.Itisthoughtthatthefirstatomiccloudoftheevaporatedheliumatomsconsistsofveryfast4He-atomswithenergies~35Kevaporatedbypositiverotonswiththespecialenergies~17K(~2ER~2×8.6KwithERrepresentingtherotonminimumenergy)correspondingtothethirdnon-dispersiveZakharenkowave.Thesecondcloudofslower4He-atomswascreatedbysurfaceelementaryexcitations(SEEsorripplons)possessingthespecialenergies~7.15Krepresentingthebindingenergy.ItwasassumedthatsuchSEEscanbecreatedbyphononsincomingtotheliquidsurfacewithspecialenergies~6.2Kcorrespondingtothefirstnon-dispersiveZakharenkowave,whichcaninteractattheliquidsurfacewiththesamephononsalreadyreflectedfromthesurfaceforlongheaterpulses.Also,somepulsed-heatercharacteristicswerestudiedinordertobetterunderstandthefeaturesofsuchheatersinlowtemperatureexperi-ments.

简介：Numericalestimatesforelectronsandmesonsparticle–antiparticlecreationfromvacuuminthepresenceofstrongelectromagneticfieldsarederived,usingthecompleteprobabilitydensityrelationofPopov’simaginarytimemethod(Popov,JETPLett.13,185(1971);Sov.Phys.JETP34,709(1972);Sov.Phys.JETP35,659(1972);PopovandMarinov,Sov.J.Nucl.Phys.16,449(1973);JETPLett.18,255(1974);Sov.J.Nucl.Phys.19,584(1974));(Popov,Phys.Let.A298,83(2002)),andwithintheframeworkofanexperimentalsetupliketheE144(Burkeetal.,Phys.Rev.Lett.79,1626(1997)).Theexistenceofcrossingpointamongpaircreationefficiencycurvesofdifferentphotonenergiesandtheroleofodd/evenmultiphotonordersintheproductionratesarediscussed.Finallyakindoftunabilityprocessbetweenthetwocreationprocessesisdiscussed.