文档介绍：学号:08908025
2012 届本科生毕业论文
题目: 土壤射频介电特性的研究
学院(系): 机械与电子工程学院
专业年级: 机电081班
学生姓名: 李福超
指导教师: 郭文川
完成日期:
土壤射频介电特性的研究
摘要
本文旨在研究含水含盐土壤的介电特性,并建立含水含盐土壤的混合介电模型。为达到这个目的,通过矢量网络分析仪测量介电模型与土壤介电常数之间的对应参数,从而为监测土壤盐碱化和开发相关测量仪器提供理论和实验基础。
样品采集于杨凌本地,并配制成不同含盐量、含水量的60个土壤样品,通过微波矢量网络分析仪共轴探头技术测量样品的介电常数,定性分析土壤介电常数(虚部)与土壤含盐量(0%~%)之间、信号频率(10MHz~)、温度(5℃~50℃)的关系。最终通过软件Design-Expert确定土壤介电模型中的待定参数;从而得到最佳频率下土壤介电虚部经验模型。
本文的主要结论有:
含盐量对介电常数虚部的影响随频率增大而降低;干燥土壤的盐分对土壤的介电常数影响较小,对于湿润土壤而言,对土壤的介电常数影响较大;在相对湿润的土壤中,对非盐碱化土壤而言,介电常数虚部远远小于实部;但对盐碱化土壤而言,介电常数虚部远远大于实部。所有这些结果表明在开发仪器监测土壤含盐量和土壤盐碱化程度方面,具有很大的潜力。通过复介电常数土壤反映含盐量是完全可能的。
关键词: 土壤盐碱化;复介电常数;共轴探头技术;Design-Expert
Radio frequency dielectric properties of soil
Abstract
The paper aimed to study the dielectric properties of constant of moisture salt soil and establish mixture model. To fulfill the purpose, Through the work analyzer measure dielectric model and soil dielectric constant correspondence between parameters,provided the theory and experiment foundation for monitoring salting of soil and the development of related measuring instrument.
Sample collection in Yang Ling and made into different salt concentration, water content of the 60 soil samples,through the microwave work analyzer were shaft probe measurement sample the dielectric constant of technology,The qualitative analysis of soil dielectric constant (imaginary part) and soil salinity (0% ~ %), between the signal frequency (10 MHz ~ GHz), temperature (5 ℃~ 50 ℃) of the relationship. Finally ,through the software Design-Expert determining soil dielectric model of the pending parameters and getting the best frequency soil dielectric imaginary part experience model.
The main conclusions of this paper:
Salt content of the imaginary part of dielectric constant impact on frequency increases, and reduce; The dry soil on soil salt of dielectric constant little influence for wet soil for soil dielectric constant impact is bigger; In the relatively wet soil, the features of