X-ray tomography study on the structure of the granular random loose packing
Xing Yi1, Qiu Yu-Peng1, Wang Zhi1, Ye Jia-Chao1, Li Xiang-Ting1, †
       

(color online) Distributions of neighbor number N and contact number Z. Error function in the inset is the best fitting with the data when ,[29] where D is the mean diameter of particles.