白果的物理特性研究

Study on Physical Characteristics of Ginkgo

我国白果产量丰富,白果的营养价值很高,同时药用价值明显。利用网络分析仪和热特性分析仪对白果的物理特性进行研究。在1~3 000 MHz频率段内,当线路热源导热率探针测量的温度从30℃增加到80℃时,在一定的含水率下,白果的介电常数ε'从7.24增加到10.89,介电损耗因子ε''从1.77上升到7.8;当温度一定时,介电常数ε'和介电损耗因子ε''都随含水率的增大而增加。由此可见,白果的比热容和热传导系数随密度、含水率的增加而增大。

China is rich in resources of ginkgo, which is high in nutritious value and has medicinal value significantly. The physical properties of ginkgo are studied by using network analyzer and thermal property analyzer. The results show that between 1-3 000 MHz the dielectric constant decreased with increasing temperature from 30 ℃ to 80 ℃ but increase with increasing moisture content, however, dielectric constant （ε＇） increase from 7.24 to 10.89, while the dissipation loss factor （ε＂） increase from 1.77 to 7.8 with increasing temperature. Dielectric constant decrease, while loss factor decreased with increasing frequency. The specific heat capacity and thermal conductivity of ginkgo increased with the increase of density and water content.