简介：

简介：

简介：TheHumisawidespreadphenomenon,reportedinmanypartsoftheworld.Itmanifestsitselfintheformofahum,rumbleandpulsing,oftenfeltasasensationmorethananaudiblesound.Startingin2011,residentsofWindsor,Ontario,Canadastartedreportingintermittentlowfrequencysound,widelyreferredtoastheHum(anddubbedtheWindsorHum).Thisreportoutlinesthedeploymentofashorttermgeophysicalfieldsurvey,performedduring2013inWindsor,Ontario,Canada,aimedatmonitoringtheairwavesignalsassociatedwiththeWindsorHum.Thesummaryofthelowfrequencysoundarraydeploymentispresentedanddiscussed.

简介：Amapoftheaverageatomicnumberoflunarrockandsoilcanbeusedtodifferentiatelithologyandsoiltypeonthelunarsurface.Thispaperestablishesalinearrelationshipbetweentheaverageatomicnumberoflunarrockorsoilandthefluxofpositionannihilationradiation(0.512-MeVgamma-ray)fromthelunarsurface.TherelationshipisconfirmedbyMonteCarlosimulationwithdatafromlunarrockorsoilsamplescollectedbyLuna(Russia)andApollo(USA)missions.AmapoftheaverageatomicnumberofthelunarrockandsoilonthelunarsurfacehasbeenderivedfromtheGamma-RaySpectrometerdatacollectedbyChang’e-1,anunmannedChineselunar-orbitingspacecraft.Inthemap,thehigheraverageatomicnumbers(ZA>12.5),whicharerelatedtodifferenttypesofbasalt,areinthemariaregion;thehighestZA(13.2)readingsareassociatedwithSinusAestuum.ThemiddleZA(~12.1)regions,intheshapeofirregularovalrings,areinWestOceanusProcellarumandMareFrigoris,whichseemstobeconsistentwiththedistributionofpotassium,rareearthelements,andphosphorusasauniquefeatureonthelunarsurface.Theloweraverageatomicnumbers(ZA<11.5)arefoundtobecorrelatedwiththeanorthositeonthefarsideoftheMoon.

简介：Twoassumptionsaretypicallymadewhenradarechosignalsfromprecipitationareanalyzedtodeterminethemicro-physicalparametersofraindrops:(1)theraindropsareassumedtobespherical;(2)multiplescatteringeffectsareignored.Radarcrosssections(RCS)areusuallycalculatedusingRayleigh'sscatteringequationwiththesimpleadditionmethodintheradarmeteorologicalequation.Weinvestigatetheextenttowhichconsiderationoftheeffectsofmultiplescatteringandofthenon-sphericalshapeswithinactualraindropswarmswouldresultinRCSvaluessignificantlydifferentfromthoseobtainedbyconventionalanalyticalmethods.First,weestablishsphericalandnon-sphericalraindropmodels,withGamma,JD,JT,andMPsizedistributions,respectively.WethenuseXFDTDsoftwaretocalculatetheradarcrosssectionsoftheaboveraindropmodelsattheS,C,XandKuradarbands.OurXFDTDresultsarethencomparedtoRCSvaluescalculatedbytheRayleighapproximationwithsimpleadditionmethods.Wefindthat:(1)RCSvaluescalculatedusingmultiplescatteringXFDTDsoftwarediffersignificantlyfromthosecalculatedbythesimpleadditionmethodatthesamebandforthesamemodel.Inparticular,forthesphericalraindropmodels,therelativedifferencesinRCSvaluesbetweenthemethodsrangefromamaximumof89.649%toaminimumof43.701%;forthenon-sphericalraindropmodels,therelativedifferencesrangefromamaximumof85.868%toaminimumof11.875%.(2)OurmultiplescatteringXFDTDresults,comparedtothoseobtainedfromtheRayleighformula,againdifferatallfoursizedistributions,byrelativeerrorsof169.522%,37.176%,216.455%,and63.428%,respectively.Whennonsphericaleffectsareconsidered,differencesinRCSvaluesbetweenourXFDTDcalculationsandRayleighcalculationsaresmaller;attheabovefoursizedistributionstherelativeerrorsare0.213%,0.171%,7.683%,and44.514%,respectively.RCSvaluescomputedbyconsideringmultiplescatteringandnon-sphericalparticleshapesarelargerthanRayleighRCS