| 摘要: |
| [目的]了解火柿果实的电学特性,探讨利用电学特性进行无损检测的可行性.[方法]以火柿果实为材料,研究其成熟衰老过程中,当电场频率为100～4×106Hz时,复阻抗、相对介电常数、并联等效电感、电导率等电学参数的变化情况.[结果]随着频率的增加,火柿果实的复阻抗和并联等效电感下降,电导率逐渐上升,相对介电常数和介电损失呈波状变化.在所测频率范围内,随贮藏时间的延长,果实复阻抗、并联等效电感下降,而相对介电常数、介电损失和电导率上升.[结论]106Hz可作为火柿果实无损检测特征频率,在此频率下,衰老火柿果实的相对介电常数是刚采摘果实的3.5倍. |
| 关键词: 火柿果实 介电特性 介电常数 无损检测 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(30471001) |
|
| Study on the post-harvest dielectric properties of persimmon fruit |
|
|
| Abstract: |
| 【Objective】 Dielectric properties of persimmon were studied in order to find the possibility of non-destructive testing using dielectric properties.【Method】 Dielectric properties including impedance,dielectric constant,inductance in parallel equivalent circuit mode and conductivity etc.of persimmon fruit were investigated over a frequency range from 100 Hz to 4 MHz at room temperature.【Result】 Both impedance and inductance in parallel equivalent circuit mode of persimmon fruit decreased with increasing frequency at room temperature,but conductivity of persimmon fruit increased.Both dielectric constant and loss factor had a peak at 1 MHz.It was also found that both impedance and inductance in parallel equivalent circuit mode of persimmon fruit decreased with prolonging period of shelf life at room temperature at constant frequency,but conductivity,dielectric constant and loss factor increased.【Conclusion】 A characteristic frequency for nondestructive measurement of persimmon fruit is 1 MHz where dielectric constant of senile persimmon fruit is 3.5 times more than that of fresh one. |
| Key words: persimmon fruit dielectric property dielectric constant non-destructive testing |
