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出 处:《Journal of Forestry Research》2004年第3期207-210,共4页林业研究(英文版)
基 金:ThisstudyisPartof2000-4-13in"948"ProjectfromtheStateForestryAdministrationofP.R.China
摘 要:The sound absorption coefficients of wood and wood boards for five eucalypt species (Eucalyptus urophylla, Euca-lyptus urophylla E. grandis, Eucalyptus urophylla E. tereticornis, Eucalyptus urophylla E. camaldulensis and Eucalyptus cloeziana) that were collected from plantation in Dongmen Forestry Center of Guangxi Province, China were tested with stand-ing wave method and their sound absorption properties were also compared. The results showed that the sound absorption co-efficients of the five eucalypt wood species did not change evidently below 1000 Hz, but above 1000 Hz their sound absorption coefficients increased with the increasing frequency. The difference in sound absorption coefficient among five species of eucalypt wood is not evident at the tested frequency range (200-2000 Hz), but the sound absorption property of Eucalyptus urophylla at low frequency is better than that of other four species. The sound absorption coefficient of the tangential-sawn board is higher than that of the radial-sawn board. The sound absorption property of eucalypt wood of 0.5 cm in thickness is much better than that of 1.0 cm in thickness. It is concluded that wood sound absorption properties of eucalypts are affected by their board thickness and the type of sawn timber within the testing frequency, but the variance of wood sound absorption property among the five tested species is not significant.本文以广西东门林场的人工林尾叶桉(Eucalyptusurophylla),尾巨桉(EucalyptusurophyllaE.grandis),尾园桉(E.urophyllaE.tereticornis),尾赤桉(E.urophyllaE.camaldulensis)和大花序桉(E.cloeziana)木材为主要材料,用驻波管法测试了五种桉树木材的吸声系数,比较了这些桉树木材的吸声性能,结果显示五种桉树木材的吸声系数在频率1000赫兹之内变化不大,之后随频率的增加吸声系数也在增加。在频率200至2000赫兹范围内,五种桉树木材的吸声系数差异不显著,在低频区域,尾叶桉的吸声性能较好。在所测试的声波频率范围内,桉木弦锯板的吸声系数高于径锯板;0.5厘米厚的锯材的吸声性能好于1.0厘米厚的锯材;因此,桉木板材的种类和板材的厚度影响其吸声性能,但五种桉树木材的吸声性能差异不显著。图2表4参6。
关 键 词:WOOD Standing wave method Sound absorption coefficient Eucalypt plantation
分 类 号:S781.38[农业科学—木材科学与技术]
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