Studying dielectric properties of heterogeneous systems is challenged by a problem of uncertainty of the ratio between dielectric permittivity of the system and dielectric permittivities of its components. Such ratios can be obtained in some cases using theoretical effective medium models. However, such models have not yet been developed for all the systems possible. Particularly, there is no effective medium model with filamentary inclusions. Such a theoretical model elaborated based on the fundamental principles of electrodynamics of continuous media is suggested in the present work. Any point of a filamentary inclusion with a length that is significantly greater than the thickness can be regarded as being located in a long cylinder-like fragment of the inclusion with stochastic direction of the cylinder axis relative to the external electric field. With this regard, electric field strength and electric induction values were averaged across the entire volume of a two-phase dielectric material. As a result, a model linking the dielectric permittivity of the two-phase system and the dielectric permittivities of both phases was elaborated. The model appears to be highly relevant for studying solutions of biopolymers, such as nucleic acids, fibrillar proteins and protein aggregates, polysaccharides, by means of electrical impedance spectroscopy, dielectric spectroscopy, and terahertz time-domain spectroscopy. The suggested theoretical model was successfully validated on a DNA solution within the terahertz region.

研究异质系统的介电特性受到系统介电常数与其组件介电常数之间比率不确定性问题的挑战。在某些情况下，可以使用理论有效介质模型获得此类比率。但是，尚未为所有可能的系统开发此类模型。特别是，没有有效的包含丝状夹杂物的介质模型。在目前的工作中提出了这种基于连续介质电动力学基本原理的理论模型。长度显着大于厚度的丝状夹杂物的任何一点都可以被认为位于夹杂物的长圆柱状片段中，圆柱轴相对于外部电场的方向是随机的。在这方面，电场强度和电感应值在两相介电材料的整个体积上取平均值。结果，详细阐述了将两相系统的介电常数与两相的介电常数联系起来的模型。该模型似乎与通过电阻抗光谱、介电光谱和太赫兹时域光谱研究生物聚合物的溶液高度相关，例如核酸、纤维状蛋白质和蛋白质聚集体、多糖。