简介：Themechanicalpropertiesofwoodpowder/polypropy!enecompositeswithdifferentwoodparticlesizesandwoodspecieshavebeenstudied.AllofthewoodparticiesizesincreasedtheE-modulusofthecomposites.Tensiletestsshowedthatwoodpartidesizeshadanegativeeffectontheelongationatbreakandthetensilestrengthofthecompositeshasbeenimprovedwhenwoodparticlesizeswerebe(ow150μm(below100mesh).Fortheimpacttests,thewoodpartidesizeshadanegativeeffect,buttheMDFf...

简介：ThecurrentresearchfocusesonsoilparticleseparateandtotalorganiccarbonandnitrogeninQuercusaquifolioidesforestinBalangshan,WolongNaturalReserve,Sichuan,andtheircorrelationattreealtitudinalgradient.Theresultshowsthat:ThesoilparticleseparateofQ.quifolioidesforestismainlyofsilts,andthesoiltextureismediumtexturedsoils;Thecontentsofsoiltotalorganiccarboncontentandnitrogencontentin0-15cmlayerarehigherthanthatin15-30cmlayerindifferentattitudegradients;thetotalorganiccarboncontentinthetopsoilshowsalow-high-lowtendencyatdifferentaltitudinalgradients,whereasthatofthesubsoilshowsagrowingtendency;TheC/NratioofQ.aquifolioidesforestisrelativelysmall,withanaverageof12.77;Thecorrelationanalysisbetweenthesoiltotalorganiccarbonandnitrogencontentandsoilparticleseparaterespectivelytellsus:contentsofsoilorganiccarbonisverysignificantlypositivelycorrelatedwithtotalnitrogeninthetwosoillayers(P<0.01)at3549m,nocorrelationat2551m;thecontentsoftotalorganiccarbonandnitrogenareverysignificantlypositivelyrespectiverespectivelywithcoarsesiltcontentin0-15cmand15-30cmsoillayers(P<0.05),butnegativelywithclayindifferentlayers(P<0.05)in0-15cmsoillayerat3549m,significantlypositively(P<0.05)andverysignificantlypositivelycorrelated(P<0.01)respectivelywithcoarsesiltcontentindifferentsoillayersat3091m,verysignificantlyandsignificantlypositivelycorrelatedrespectivelywithfinesandcontentindifferentsoillayersat2551m,butnegativelywithfinesiltcontentin15-30cmsoillayer.Finally,inthispapertheresultspresentedthatrelationshipsamongsoilparticleseparateandtotalorganiccarbonandnitrogencontentarequitecomplicationsinQ.aquifolioidesforestatdifferentaltitudinalgradient.