Relationship between acoustic emission characteristics generated with water conductivity of xylem and wood anatomy

幼苗和成树的声发射与蒸腾作用或血管解剖结构有关。AE事件与蒸腾量（即通过血管的水流）之间存在显著关系。从成树木质部切下小标本，用于水电导率测试。对结果进行了流体动力学讨论。根据hagens - poiseuille定律，流速由压差、容器直径和容器数量决定。声发射事件与血管数目有一定的关系。当水流速度超过一定值时，声发射的产生与流速成正比。幼苗和乔木产生的声发射与植物的气候和水分条件有关。声发射技术可以应用于植物水分胁迫的检测和树木的诊断。为了将超声技术应用于树木的诊断，如声发射和超声CT，有必要对木材中传播的超声特性进行研究。利用扫描声显微镜（SAM）测量了气管细胞壁上的各向同性波速。波速与微纤维角度有关。用脉冲声-超声接收机测量的横波速度取决于木材的解剖结构。

The acoustic emission from seedlings and adult trees was detected to relate to the transpiration or anatomical structure of vessels. There was significant relationship between AE events and amount of transpiration that is water flow through the vessels. Small specimens were cut from xylem of adult trees, and used for the water conductivity testing. Results were discussed hydrodynamically. The flow rate was determined by the pressure difference, the diameter of a vessel and number of vessel based on the Hagen-Poiseuille's law. There was relationship between AE events and the number of vessel. The AE generation was observed proportionally to the flow rate when the water flow velocity was over a certain value.The AE generation from seedlings and trees was depended on the climate and the water condition of the plants. It is possible to apply the AE technique to detection of the water stress of plants and to tree diagnosis. The AE generation occurred by not only the transpiration but also the shoot glowing, then the technique would be able to use for the research of tree phenologyIt is necessary to study ultrasonic properties propagating in the wood for the application of the ultrasonic to the tree diagnosis such as the AE and ultrasonic CT. The scanning acoustic microscope (SAM) was used for the measurement of isotropic wave velocity on the cell wall of tracheids. The wave velocity depended on the micro-fibril angle. The transverse wave velocity measured with a pulsar-and-receiver of the acousto-ultrasonic was depended on the anatomic wood structure.