中文摘要：

基于共价固体硬度正比于单位面积上每根化学键对压头的阻抗之和的假设．提出了估计极性共价固体硬度的微观理论。计算了新近合成的立方尖晶石结构Si3N4的理论硬度，计算值与最近报道的实验值吻合。最后．预测了高密度C3N4异构体的理论硬度。

英文摘要：

Based on the supposition that the hardness of covalent crystal is intrinsic and equivalent to the sum of resistance of each bond per unit area to indenter,a microscopic theory for the evaluation of hardness of covalent crystals is presented. The theoretical hardness of cubic spinel Si3N4 is calculated, in agreement with its experimental values reported recently. Finally, the theoretical hardness of high-density C3N4, polymorphs is predicted.