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本文把纳米晶体材料等效成由晶粒基体和晶间界面夹杂组成的复合材料，对纳米材料屈服应力特征作了详细讨论．依此得到了纳米晶体材料屈服应力偏离Ｈａｌｌ一Ｐｅｔｃｈ关系的尺寸范围，这一范围强烈地依赖于界面的性质．依据所得到的结果，解释了屈服应力随晶粒尺寸减小而降低的反常实验现象．文中还指出屈服应力对晶粒尺寸的依赖曲线可划分为线性区，非线性区，反常偏离区和不确定区四个区域，屈服应力的尺寸效应不但需要指定晶粒尺寸的范围，而且还取决于界面的性质．在细观理论的基础上，对夹杂体弹性模量的确定提出了具体的建议．
In this paper, the nanocrystalline material is equivalent to the composite material consisting of the grain matrix and intercrystalline interface. The yield stress characteristics of nanomaterials are discussed in detail. The size range of the yield stress of the nanocrystalline material deviating from the Hall-Petch relationship is obtained in this way, and this range strongly depends on the nature of the interface. Based on the results obtained, anomalous experimental phenomena in which the yield stress decreases as the grain size decreases are explained. It is also pointed out that the dependence of yield stress on the grain size can be divided into four regions: linear region, nonlinear region, anomalous deviating region and indefinite region. The size effect of yield stress not only needs to specify the range of grain size, but also depends on The nature of the interface. Based on the theory of meso-detail, some suggestions are put forward to determine the elastic modulus of inclusions.