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干燥处理材的动态粘弹性 总被引:3,自引:0,他引:3
该文采用高温干燥、低温干燥和真空冷冻干燥3种干燥方法分别对杉木人工林木材进行干燥处理。用动态力学分析仪测定了3种干燥处理材在温度-120~250℃,测量频率1、2、5、10 Hz的动态粘弹性。结果表明:①储存模量和损耗模量均表现为高温干燥处理材最大,真空冷冻干燥处理材最小。②高温干燥处理材和低温干燥处理材的损耗模量温度谱中,从高温至低温方向可依次观察到3个力学松弛过程,其分子运动归属分别是木材细胞壁非结晶区中聚合物的微布朗运动、木材细胞壁聚合物分子的扭转振动和木材细胞壁无定型区中伯醇羟基的回转取向运动。③真空冷冻干燥处理材的损耗模量温度谱可观察到4个力学松弛过程,新增加的松弛过程是由木素分子的微布朗运动引起的。这说明木材经过高温干燥或低温干燥处理,由于受到热的作用,木材细胞壁分子链之间可能发生了一定程度的交联,从而限制了木素分子的微布朗运动。 相似文献
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杉木和I-72杨人工林木材干缩性质的研究 总被引:2,自引:0,他引:2
通过对杉木和I-72杨人工林木材南北向、不同高度位置、不同径向位置横向干缩(弦、径向)的测量,研究上述3个因素对2种木材横向干缩(弦、径向)的影响规律。结果表明:南北向的不同对杉木和I-72杨人工林木材的干缩均无显著影响;高度位置的不同对杉木和I-72杨木的弦向干缩均有显著影响,而对径向干缩则无显著影响;径向位置的不同对杉木和I-72杨人工林木材的径、弦向干缩均有极显著影响:从树皮到髓心,木材径、弦向干缩逐渐减小,与其基本密度的变化趋势一致。 相似文献
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介绍"十一五"国家科技支撑计划"高强度结构材加工利用技术"课题中,对我国主要的商品林树种之一——落叶松,在规格材的优化加工、分级、无损检测、强度性能测试及木构件连接等关键技术研究方面,取得的重点创新成果。这些成果开创性地解决了我国利用国产资源加工结构用规格材的关键性和共性技术问题,并且为我国落叶松资源的高效利用,提供了新的技术途径。 相似文献
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Influence of Ammoniacal Copper Quaternary treatments on mechanical properties of blue-stained Lodgepole Pine wood 总被引:1,自引:0,他引:1
Three concentrations (2.8%, 2.0%, 1.2%) of Ammoniacal Copper Quaternary (ACQ) was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modules of elasticity (MOE), modules of rupture (MOR), toughness and shearing strength parallel to grain on tangential surface, are tested according to the criteria GB1927-1943-91. Non-treated sample were also tested according to the same procedure. The results showed that the three groups specimen impregnated by different concentrations of ACQ solution met the AWPA standard 2003 of America (UC4A 6.4g/cm^3). There were significant difference of toughness between treated wood and non-treated wood (p=0.01), but there were no statistically significant differences among three concentrations in terms of toughness, and toughness of treated wood was approximately 20% lower than non-treated. MOR, MOE as well as sheafing strength parallel to grain were found to be not significantly different between treated wood and non-treated one, and there were no statistically significant difference among three concentrations of ACQ too. Toughness, MOR, MOE and sheafing strength parallel to grain increased with decrease of concentration of ACQ, but they were hardly affected by ACQ preservatives. 相似文献