Fundamental Study on Wood Quality by Electrical Conduction and Gas Permeability

通过导电性和透气性对木材质量进行基础研究

• 批准号: 61560197
• 负责人: TSUTSUMI Juichi
• 金额: $ 1.54万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560197/
• 关键词: Electrical conduction; Gas permeability; Wood quality; Wood morphology; 木材組織; 木材構造

The electrical conductivities and air permeabilities of 20 hardwood species and Larix were studied in relation to specific gravity and wood morphology in order to understand a fundamental aspect of the physical properties for evaluating wood quality.The conductivity at a given moisture content had large variation among species. On the other hand, the effect of moisture concentration per unit wood volume was highly correlated to basic density. Therefore the conductivity variation among species was assumed to be mainly caused by the difference of moisture retention with wood specific gravity and also by the physical change of adsorbed water with moisture retention. The intra-structure of cell wall and the cell dimension may be another factors in the difference among species, because the conductivity of cell wall itself was shown to have the variation among species and to be correlated to average microfibril angle in tracheid. The results suggested that, if the relationship between moistu … More re retention and wood structure was sufficiently realized, conductivity could be a reasonable index for specific gravity as well for moisture content.Although vessel element element and tracheid were supposed to be main flow passages in wood, air permeability could not be correlated to the volumetric percentage of their lumens. It is because the flow passages in wood should be more complicated by interelements structure and also by occlusion of vessels and pits. Therefore the measured values of vessel radius and total number of vessels per unit cross sectional area were compared with the estimated values from permeability measurement by aplying the two elements model in series. A reasonable agreement between the two was found out in the species of diffuse-porus hardwoods with scalariform perforation and without occlusion of vessels, but was not in the species with high variation in vessel radius as well as for those with occluded vessels. Furthermore the percentage of occluded area to total vessel area per unit cross sectional area may be calculated. From the results mentioned, air permeability is recognized as synthetic index for wood structural classification because of its sensibility for the difference in passage among species. Less

研究了20种硬木和落叶松的电导率和透气性与木材比重和木材形态的关系，以了解评估木材质量的物理性质的基本方面。在一定含水量下，不同树种的电导率差异较大。另一方面，单位木材体积水分浓度的影响与基本密度高度相关。因此，我们认为树种间电导率的变化主要是由于木材的保湿率与木材比重的差异，以及吸附水分与保湿率的物理变化。细胞壁内部结构和细胞尺寸可能是物种间差异的另一个因素，因为细胞壁本身的电导率在物种间存在差异，并且与管胞微纤维的平均角度有关。结果表明，如果充分认识木材含水率与木材结构之间的关系，电导率可以作为木材比重和含水率的合理指标。虽然管胞和管胞被认为是木材的主要流通通道，但透气性与它们的管腔体积百分比没有相关性。这是因为木材中的流动通道应该由于元素间结构以及血管和凹坑的闭塞而更加复杂。因此，将单位横截面积的血管半径和血管总数的实测值与渗透率测量的估计值串联应用二元模型进行比较。在具有鳞状穿孔和血管不闭塞的散孔硬木种中，两者之间存在合理的一致性，但在血管半径变化大的树种和血管闭塞的树种中则不存在这种一致性。此外，可以计算单位横截面积闭塞面积占总血管面积的百分比。以上结果表明，透气性对树种间通道的差异具有敏感性，可作为木结构分类的综合指标。少

项目成果

Kuroda, N.: "Relationship of Hardwood Morphology to Air Permeability" Bulletin of the Kyushu University Forest. 58. (1988)

Kuroda, N.：“硬木形态与透气性的关系”九州大学森林通报。

堤壽一: 九州大学農学部木材理学教室・研究資料. 87-1. (1987)

Juichi Tsutsumi：九州大学农学部木材科学系，研究资料87-1。

黒田尚宏: 九州大学演習林報告. 58. (1988)

黑田直宏：九州大学实验森林报告 58。（1988）

堤壽一: 九州大学演習林報告. 60. (1989)

堤十一：九州大学实验森林报告 60。（1989）

Kuroda, N.: "Effects of Specific Gravity and Morphological Factors on Electrical Conduction in Hardwoods" Bulletin of the Kyushu University Forest. 58. (1988)

Kuroda, N.：“比重和形态因素对硬木导电的影响”九州大学森林通报。