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Multi-layer configuration for the cathode electrode of polymer electrolyte fuel cell
This paper conducts a one-dimensional theoretical study on the electrochemical phenomenon in the dual-layer cathode electrode of polymer electrolyte fuel cells (PEFCs) with varying sub-layer thicknesses, and further extends the analysis to a triple-layer configuration. We obtain the explicit solution for a general dual-layer configuration with different layer thicknesses. Distributions of the key quantities such as the local reaction current and electrolyte overpotential are exhibited at different ratios of the ionic conductivities, electrochemical kinetics, and layer thicknesses. Based on the dual-layer approach, we further derive the explicit solutions for a triple-layer electrode. Sub-layer performances are plotted and compared. The results indicate that the layer adjacent to the electrolyte membrane may contribute a major part of the electrode faradic current production. The theoretical analysis presented in this paper can be applied to assist electrode development through complicated multi-layer configuration for cost-effective high performance electrodes. © 2010 Elsevier Ltd
The structure and magnetism of graphone
Graphone is a half-hydrogenated graphene. The structure of graphone is
illustrated as trigonal adsorption of hydrogen atoms on graphene at first.
However, we found the trigonal adsorption is unstable. We present an
illustration in detail to explain how a trigonal adsorption geometry evolves
into a rectangular adsorption geometry. We check the change of magnetism during
the evolution of geometry by evaluating the spin polarization of the
intermediate geometries. We prove and clarify that the rectangular adsorption
of hydrogen atoms on graphene is the most stable geometry of graphone and
graphone is actually antiferromagnetic.Comment: 11 pages, 4 figure
Measuring dynamic oil film coefficients of sliding bearing
A method is presented for determining the dynamic coefficients of bearing oil film. By varying the support stiffness and damping, eight dynamic coefficients of the bearing were determined. Simple and easy to apply, the method can be used in solving practical machine problems
The spin-polarized state of graphene: a spin superconductor
We study the spin-polarized Landau-level state of graphene. Due to
the electron-hole attractive interaction, electrons and holes can bound into
pairs. These pairs can then condense into a spin-triplet superfluid ground
state: a spin superconductor state. In this state, a gap opens up in the edge
bands as well as in the bulk bands, thus it is a charge insulator, but it can
carry the spin current without dissipation. These results can well explain the
insulating behavior of the spin-polarized state in the recent
experiments.Comment: 6 pages, 4 figure
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