A Study on Electro-chemical Phenomena on Soil Surface and Its Application

众所周知，水分子具有非常大的电偶极矩。通过光谱学测量偶极矩作为介电常数。但是，介电常数的测量值受界面极化的影响，需要消除这种影响，并从测量的介电常数中找出水分子偶极矩的净贡献。在微波频率范围内（100 MHz-10 GHz），介电常数主要受偶极矩的影响。因此，在该频率范围内测量土壤的介电常数，可以在不受界面极化效应干扰的情况下测量水分子的偶极矩，本文提出了一种新的介电常数测量的频域折射法（FDR）理论，并在此基础上提出了一种实验室和现场测量都十分方便的方法。该方法成功地应用于土壤体积含水量、冻结水、吸附水和结合水的测定，为土壤水分的快速无损现场测定提供了有力的工具。也就是说，该方法使我们能够检测土壤层和测量土壤水分分布，这是土壤界面处的另一种宏观现象。

A water molecule is known to have an extraordinary large electric dipole moment. The dipole moment is measured as a dielectric constant by a spectroscopy. However, the obtained values of the dielectric constants are affected by polarization of the interface, it is needed to eliminate the influence and to find out net contribution of the dipole moment of water molecules from the measured dielectric constants. In a frequency range of micro-wave (100MHz-10GHz), dielectric constants are affected mainly by the dipole moment. Therefore, the measurement of dielectric constants of a soil in this frequency range make it possible to measure the dipole moment of the water molecule with no disturbance of interface polarization effect.In this study, the author developed a new theory of Frequency Domain Refractometry (FDR) on dielectric constant measurement.Based on the theory, he developed a single prove method which is quite convenient in both laboratory and field measurement. This method was confirmed to be applied successfuly to volumetric soil moisture measurement, frozen water measurement, adsorbed water detection and bonding water detection, as well.In addition, the method was found to offer a powerful tool for quick and nondestructive in si-tu measurement of soil moisture which had been considered very difficult. Namely, the method enables us to detect soil strata and to measure soil moisture distribution, that is another macroscopic phenomena at a soil interface.