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本文在60 kHz—100 MHz频率范围,对绝干至水分饱和的我国东北八种常用木材的介质损耗参数tgδ和e″进行了测量,结果如下:①tgδ和ε″随频率而变化,而且含水率不同,色散曲线的变化形式和程度也不同;②在给定频率下,tgδ因含水率W的升高而增大,并且tgδ—W曲线在单层吸附水、多层吸附水和自由水三个含水率范围的变化形式和程度不同;③木材介质损耗参数随木村密度(ρ)而增大,ε″与ρ呈紧密的线性正相关,tgδ与ρ呈微弱的正相关;④通常,木材的轴向介质损耗参数大于径向和弦向者,径向与弦向之间略有差异。在实验的基础上,分析了频率、含水率、密度和纹理方向对木材介质损耗参数的影响机理。
In the frequency range from 60 kHz to 100 MHz, the dielectric loss parameters tgδ and e “of eight common woods in northeast China from absolute dry to saturated water are measured. The results are as follows: ①tgδ and ε” change with the frequency, and the moisture content Different dispersion curves of different forms and degrees are also different; (2) at a given frequency, tgδ increased due to the increase of the moisture content W, and tgδ-W curve in a single layer of adsorbed water, multi-layer adsorbed water and free water three The moisture content of the wood is different from that of the water content; (3) The parameters of wood dielectric loss increase with the density of wood (ρ), ε "and ρ are close linear positive correlation, and tgδ and ρ are weak positive correlation; The axial medium loss parameter is larger than the radial chord direction, and there is a slight difference between the radial direction and the chord direction.Based on the experiment, the influence mechanism of frequency, moisture content, density and texture direction on the dielectric loss parameter of wood is analyzed.