不同年齡龍竹材材性的綜合評價.pdf

1、西南林學院碩士學位論文不同年齡龍竹材材性的綜合評價姓名：武猛祥申請學位級別：碩士專業(yè)：木材科學與技術(shù)指導教師：邱堅20080501AbstractAbstractInthisresearch，anatomicalandphysicalpropertiesofDendrocalamusgiganteus(Dragonbamboo)culmsatdifferentageswerestudiedPerimetersstudiedinclude

2、dtissuecomposition，vascularbundledensityfmermorphologyandshrinkagerateandstrengthsofculmsDragonbambooculmsconsistedof55“％t07075％groundtissue，327％to794％conductivetissueand2869％to3984％fiberDensityofvascularbundleincreasedw

3、ithculmsageandwithincreasingheight，rangingfrom151／cm2foroneyearoldculmstoamaximum198／cm2forfouryearoldculmsandfrom128／L：】tn2atthebaseto172／cm2atmidheightto223／tinzatthetopVascularbundlesweremainlyfrankedwithadetachedfibe

4、rsheath，butdouble—frankedvascularbundlesalsowereobservedinthemiddlepartofculmsatthegroundlevel。Fiberlengthdidnotvarywithculmage，butfibersatmidheightwereslightlylongerthanthoseatthebasedandtopsectionsTheaveragefiberlength

5、wasfoundtobe227mmTheaveragefiberwidthwas1912岬，andtheaverageaspectratiowas1】9Dragonbambooculmshadinternodesbetween30to45cminlengthandabasicdensitybetween0419to0670g／cm’Theculmdensityincreased麗thincreasingheight，anditalsoi

6、ncreasedwithculmage，reachingamaximumatthefonhyearThreeyearoldculmshadthelowestoven—dryvolumetricshrinkageageat128％，andshrinkagerateusuallyincreasedwithincreasingculmheightVariationofthemechanicalpropertiesofDragonbambooc

7、ulmsfollowedthevariationpaRernofitsbasicdensityie，increasedwithincreasingageandincreasingculmheightTheaveragecompressionstrength(paralleltograin)，bendingstrength，bendingmodulusandshearstrength(paralleltograin)were7623MPa