<論文>広葉樹材の構造と誘電率の異方性

Abstract

広葉樹材の3主軸方向の誘電率を,細胞壁を構成する化学成分の割合と広葉樹材の多様な組織構造が考慮されているモデルを用いて,混合用に基づいて算出し,組織構造が誘電率の異方性に及ぼす影響について考察した。一般に認められているように,繊維方向の誘電率は,繊維に直角方向のそれらに比べて大きい値を示した。放射方向と接線方向については,概して放射方向の値が大きく,両方向の差は,木材の横断面における道管の配列,放射組織の占める割合,木繊維の配列のみだれなどに依存していることが明かになった。計算値は,実験値と比較的よく一致し,広葉梅村の誘電率の異方性を表現することができた。

The dielectric constants in the three principal directions of hardwood were evaluated on the basis of the rule of mixture using the models in which proportions of the chemical constituents in the cell wall substance and various anatomical structures in hardwoods were taken into account, and the effects of the structure on the dielectric anisotropy were discussed. The dielectric constant in the longitudinal direction was greater than those in the transverse directions as is generally recognized. In the transverse directions, the dielectric constant in the radial direction was slightly greater than that in the radial direction, and this mainly depended on arrangement of vessels, percentage of ray element, and irregular array of wood fibers. The estimated values were in satisfactory agreement with the experimental ones and could express the dielectric anisotropy in hardwood.