Experimental study of segregation patterns in binary granular mixtures under vertical vibration  

作　　者：SHIQingfan YANXuequn HOUMeiying NIUXiaojuan LUKunquan 

机构地区：[1]DepartmentofPhysics,BeijingInstituteofTechnology,Beijing100081,China [2]InstituteofPhysics,ChineseAcademyofSciences,Beijing100080,China

出　　处：《Chinese Science Bulletin》2003年第7期627-629,共3页

基　　金：supported by the National Key Program for Basic Research(Grant No.R39799N);the National Natural Science Foundation of China.

摘　　要：We report the experimental observations of the segregation patterns in initially well mixed copper and glass spheres subjected to a vertical sinusoidal vibration at differ-ent values of acceleration G and frequency f. A segregation phase diagram is obtained, which includes Brazil nut (BN), Reversed-BN (RBN) and sandwich segregation patterns at different G and f. The stable RBN segregation is experimen-tally found for the first time, in which large heavy particles move down to the bottom and form the lower-layer while small particles rise to the top and form an upper-layer. The boundary values (G, f), which separate regions of different patterns, depend on system’s initial condition, i.e. hysteresis exists.We report the experimental observations of the segregation patterns in initially well mixed copper and glass spheres subjected to a vertical sinusoidal vibration at differ-ent values of acceleration G and frequency f. A segregation phase diagram is obtained, which includes Brazil nut (BN), Reversed-BN (RBN) and sandwich segregation patterns at different G and f. The stable RBN segregation is experimen-tally found for the first time, in which large heavy particles move down to the bottom and form the lower-layer while small particles rise to the top and form an upper-layer. The boundary values (G, f), which separate regions of different patterns, depend on system's initial condition, i.e. hysteresis exists.

关 键 词：颗粒物质 多层结构 垂直振动 二元颗粒混合物 分离模式 实验性研究 

分 类 号：O327[理学—一般力学与力学基础]