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为研究环境温度对活立木内电阻值的影响,采用树木电阻断层成像仪在不同温度下对落叶松和小叶杨两种活立木进行检测,获取截面二维电阻图像并分析其变化,量化横截面内各点电阻值及其与温度之间的关系。结果表明:1落叶松横截面心材电阻值较低,边材较高。随温度降低,边材红色区域(高电阻区)面积减少,心材蓝色区域(低电阻区)面积增大;而小叶杨电阻图像呈现完全相反的规律。但随温度降低,两树种整体平均电阻值均增大。2样本立木电阻值与环境温度之间存在极显著的指数函数关系(P<0.01),模型相关系数R≥0.822,小叶杨甚至高于0.926,因此认为模型有很好的拟合优度。3在落叶松样本立木中,当温度大于0℃时,横截面内沿径向分布的各点电阻值之间变化不明显,最大差值为1 236Ω(3.0℃时);而温度小于0℃时波动很大,最大差值达到3 299Ω(-5.0℃时),曲线存在较为明显的两个波谷和中间一个波峰。4在小叶杨样本立木中,随环境温度降低,横截面内沿径向分布的各点电阻值都呈增大趋势;从边缘到髓心再到另一侧边缘,沿径向分布的电阻值呈由低向高逐渐增大、到最大值后再逐渐降低的趋势。
In order to study the effect of ambient temperature on the electrical resistance of live wood, two kinds of live trees, Larch and Populus simonii, were tested by tree resistivity tomography at different temperatures to obtain two-dimensional cross-sectional resistance images and analyze the changes. The quantitative cross-section The resistance of each point and its relationship with the temperature. The results showed that: 1 The larch cross-section heartwood resistance value is low, the sapwood is higher. With the decrease of temperature, the area of sapwood red area (high resistance area) decreased, the area of heartwood blue area (low resistance area) increased, while the resistance image of poplar showed the opposite law. However, with the decrease of temperature, the average resistance of the two species increased. There was a very significant exponential function (P <0.01) between the resistance value of standing wood and the ambient temperature. The correlation coefficient of the model R≥0.822 and Populus simonii even higher than 0.926, so the model has good fitting goodness. In the larch sample stand, when the temperature is higher than 0 ℃, there is no obvious change between the resistance values at each point distributed in the radial direction, the maximum difference is 1 236Ω (3.0 ℃); while the temperature is less than 0 ℃ When the maximum difference reaches 3 299Ω (-5.0 ℃), there are two obvious wave troughs and one crest in the middle of the curve. In the stand of Populus simonii, the resistance values of each point distributed in the radial direction of the cross section increased with the decrease of the ambient temperature. The resistance value distributed along the radial direction from the edge to the medulla and then to the other side edge From low to high gradually increased, to the maximum and then gradually reduce the trend.