简介:Anewmethodforthedeterminationoftracecalciumbysolidsubstrate-roomtemperaturephosphorimetryisestablished.ItisbasedonthefactthatchromeazurolsazurolS-phenanthroline-NaCMC(CAS-phen-NaCMC)systemcanemitstrongandstableroomtemperaturephosphorescence(RTF)onthesolidsubstrateinthefilterpaper.Ca2+andphenanthrolinecanformcomplexionCa(phen)32+,whichwillformcomplex[Ca(phen)3(CAS)2]withCAS.Intheresult,thenumberofCASmoleculesineachspotincreased,causingsharpincreaseoftheRTPsignaloftheCAS-phen-NaCMCsystem.
简介:Inthenormal-modetheoryofMorse,itgivesaseriesofnormalmodesasthesolutionofforcedvibrationinaroom.Butactuallythereisalwaysthedirectradiationbesidesthenormalmodeswhichrepresentthereverbrantsoundfieldonly.Thereasonisthatthenormalmodeswereassumedonlyinthesource,andnaturallynormalmodesonlyareobtainedinthesolution.Atheoryofdoublesourceisproposed,thatthesoundsourceisboththesourceofthedirectradiationasifinfreespacebeforetheboundarysurfaceswerereachedbythedirectradiation,andafterthefirstreflectionfromtheboundarysurfaces,thesourceofthereflectedwavelets,randomlydistributedbothinspaceanintimeontheboundarysurfacesthatbuildupthenormalmodesafterfurtherreflections.Thewaveequationisformedaccordingly,andthesolutionofthewaveequation,thesoundfieldinaroom,containsexplicitlyboththedirectradiationandthereverberantsoundformedofnormalmodes.Theapproximatemeansquaresoundpressureisfoundtobethedircetsounddeterminedbythesoundpowerofthesource,andreverberantsounddeterminedbythesoundpowerreducedbyafactorofπ/2,differentslightlyfromtheresultobtainedfromenergyconsideration,ifthesourceispuretone.Thereisessentiallynodifferenceforasourceofbandnoise.