简介：InordertoexplorethefeasibilityofusingX-raytomeasuremoisturecontentinthedryingprocessandhaveafurtherstudyontheeffectofprecisionofmoisturecontentwhenscanningthroughdifferentgraindirections,X-rayscanningmethodandweightingmethodwereusedtomeasureaveragemoisturecontentofCunninghamialanceolataduringhotairdrying.Theresultsshowthatthemoisturecontentvaluesoftwomethodswereveryclosetooneanother,thedeterminationcoefficientsofbothwerehighlycorrelatedwithavalueover0.99,andtheabsolutedeviationwasbelow2%;whenscanningalongradialdirectionandlongitudinaldirection,theprecisionsofaveragemoisturecontentwerehigherthanthatofthetangentialdirection,butthedeviationcanbenegligibleintheactualmeasurement;inthepracticalapplication,theeffectofgraindirectiononprecisionofmoisturecontentmeasurementcouldnotbetakenintoaccountwhenusingX-raytomeasurethemoisturedistributionofwood.

简介：TheabsorptionandenrichmentofheavymetalelementsbyleavesofPopulus×euramericanacv.’Neva’wereanalyzedthroughcontentassessingofheavymetalelementsinsoilsofthreeforestlandsatFangshanDistrictinthesouthernsuburbofBeijing.TheseforestlandswithP.×euramericanacv.’Neva’plantationwerearoundwiththevarioussourcesofpollutionsuchascementmill,stonemill,sewageandgarbage.SomeofheavymetalelementssuchasCd,Pb,Cu,andZnwerefoundinthesoilsamplesandleavesofP.×euramericanacv.’Neva’grownonthethreeforestlandswhichwereinvestigated.TheresultsofinvestigationshowedthatthesoilsofthreeforestlandswerepollutedwithPb,Cd,CuandZninvaryingdegrees.ThecontentsofPb,CuandZninsoilsweresignificantlydifferentamongthethreeforestlands,whereastheaveragecontentofCd(0.0776mg·kg-1)waslessbutthatofPb,Cu,andZn(37.61,26.25and90.3mg·kg-1)weremorethantheaveragebackgroundvalueofBeijing.ThecontentsofPb,Cd,CuandZninleavesofP.×euramericanacv.’Neva’weredifferentamongthreeforestlands.Withthechangesofheavymetalcontentsinsoilsamples,therewasnoregularityonthechangesofdifferentheavymetalcontentsinleavesofP.×euramericanacv.’Neva’grownondifferentforestland.P.×euramericanacv.’Neva’canabsorbandaccumulatePb,Cd,CuandZninsoilbutshoweddifferentcapacitiesofabsorptionandaccumulationwiththeorderofCd>Zn>Cu>Pb.Especially,itsabsorptionandaccumulationcapacityforCdwasstrongwithmaximumenrichmentfactorhigherthan16andshowedhighaccumulationonlowbackground,whereasitsenrichmentcapacitiesforPbandCuwererelativelypoorerwithaverageenrichmentfactoroflessthan1.Atdifferentforestlands,thereexistedgreatdifferenceonabsorptioncapacityofP.×euramericanacv.’Neva’withthesameheavymetal.