Yinchang Li

High strength and high electrical conductivity in bulk nanograined Cu embedded with nanoscale twins

A bulk nanograined Cu sample embedded with nanoscale twins is produced by means of dynamic plastic deformation at cryogenic temperatures. It exhibits a tensile yield strength of 610 MPa and an electrical conductivity of 95% IACS at room temperature. The unique combination of a high strength and a high conductivity is primarily attributed to the presence of a considerable amount of nanoscale twins which strengthen the material significantly while having a negligible influence on electrical conductivity

Directed clustering in driven compartmentalized granular gas systems in zero gravity

Clustering of shaken fluidized granular matter in connected compartments has been observed and studied in the laboratory. This clustering behavior in granular gas systems is related to the dissipative nature of granular system, and therefore shall not depend on gravity. This clustering phenomenon in compartmental configuration may provide a means for particle depletion and transportation in microgravity environment. In this work we propose different configurations for possible directed clustering in zero gravity. The related experiment has been planned for the Chinese satellite SJ-10.

Imperfect pitchfork bifurcation in asymmetric two-compartment granular gas

The clustering behavior of a mono-disperse granular gas is experimentally studied in an asymmetric two-compartment setup. Unlike the random clustering in either compartment in the case of symmetric configuration when lowering the shaking strength to below a critical value, the directed clustering is observed, which corresponds to an imperfect pitchfork bifurcation. Numerical solutions of the flux equation using a modified simple flux function show qualitative agreements with the experimental results. The potential application of this asymmetric structure is discussed.