Zuriguel Iker, Pugnaloni Luis A, Garcimartín Angel, Maza Diego
Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Sep;68(3 Pt 1):030301. doi: 10.1103/PhysRevE.68.030301. Epub 2003 Sep 9.
We have looked into an experiment that has been termed the "canonical example" of jamming: granular material, clogging the outlet of a container as it is discharged by gravity. We present quantitative data of such an experiment. The experimental control parameter is the ratio between the radius of the orifice and the radius of the beads. As this parameter is increased, the jamming probability decreases. However, in the range of parameters explored, no evidence of criticality--in the sense of a jamming probability that becomes infinitely small for a finite radius--has been found. We draw instead a comparison with a simple model that captures the main features of the phenomenon, namely, percolation in one dimension. The model gives indeed a phase transition, albeit a special one.
我们研究了一个被称为堵塞“典型例子”的实验：粒状材料在重力作用下从容器中排出时堵塞容器出口。我们给出了该实验的定量数据。实验控制参数是孔半径与珠子半径之比。随着该参数的增加，堵塞概率降低。然而，在所探索的参数范围内，未发现临界性的证据——即对于有限半径，堵塞概率变得无限小的那种临界性。相反，我们将其与一个捕捉该现象主要特征的简单模型进行了比较，即一维渗流模型。该模型确实给出了一个相变，尽管是一个特殊的相变。
