An analytical solution is derived with the mirror image method of the velocity field of an inviscid liquid induced by a growing bubble from a plate orifice. The flow is assumed potential, and the bubble shape is ideal...An analytical solution is derived with the mirror image method of the velocity field of an inviscid liquid induced by a growing bubble from a plate orifice. The flow is assumed potential, and the bubble shape is idealised as spherical. In deriving the motion equation, the spherical image of a point source, which is a combination of a point source and a line source, is proved approximate to a double source. This approximation enables continuation of the effectiveness of mirror image method to the case studied in this paper. The derived velocity potential equation is verified for the boundary conditions on the bubble surface and the orifice plate. The streamlines of the velocity field are presented and compared with experimental results in the literature.展开更多
Designing efficient and stable non-precious metal HER(hydrogen evolution reaction)electrocatalysts with high large current density adaptability is significant for industrial application of hydrogen production by water...Designing efficient and stable non-precious metal HER(hydrogen evolution reaction)electrocatalysts with high large current density adaptability is significant for industrial application of hydrogen production by water electrolysis.Herein,a facile strategy was developed to construct a multi-phase Ni3 P-Co_(2)P-(Ni-Co)film with self-supporting hierarchically micro/nano-porous structure by using bubble template method electrodeposition of self-supporting micro-porous Ni Co P film,oxygen-free annealing for phase separation producing Ni_(3)P-Ni-Co_(2)P-Co structure,and acid etching for constructing surface nano-porous structure.The effective active sites for HER was significantly increased due to the hierarchically micro/nano-porous structure,which not only enlarged the surface roughness,but enhanced the bubble detachment by improving the hydrophilicity.Meanwhile,the HER electrolysis durability was improved benefiting from the Ni_(3)P-Co_(2)P phases with high corrosion resistance(especially in acid solution)and the self-supporting film structure without binder.Consequently,the Ni Co P-OA-AE film exhibited high HER catalytic performance,which delivered a current density of 10 m A cm^(-2)at a low overpotential of 42.9 and 39.7 m V in 1 M KOH and 0.5 M H_(2)SO_(4),respectively.It also possessed high long-term electrolysis durability,and the cell voltage of water electrolysis using self-supporting porous Ni Co P-OA-AE||Ir O_(2)-Ta_(2)O_(5) electrolyzer at 500 m A cm^(-2)for 250 h in 0.5 M H_(2)SO_(4 )is only 2.9 V.展开更多
文摘An analytical solution is derived with the mirror image method of the velocity field of an inviscid liquid induced by a growing bubble from a plate orifice. The flow is assumed potential, and the bubble shape is idealised as spherical. In deriving the motion equation, the spherical image of a point source, which is a combination of a point source and a line source, is proved approximate to a double source. This approximation enables continuation of the effectiveness of mirror image method to the case studied in this paper. The derived velocity potential equation is verified for the boundary conditions on the bubble surface and the orifice plate. The streamlines of the velocity field are presented and compared with experimental results in the literature.
基金supported by the National Natural Science Foundation of China(Nos.51804023 and 51874020)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-18-007A1)+1 种基金the China Postdoctoral Science Foundation(Nos.2019M650489 and 2019T120046)Taishan Scholars Program(No.tsqn201909087)。
文摘Designing efficient and stable non-precious metal HER(hydrogen evolution reaction)electrocatalysts with high large current density adaptability is significant for industrial application of hydrogen production by water electrolysis.Herein,a facile strategy was developed to construct a multi-phase Ni3 P-Co_(2)P-(Ni-Co)film with self-supporting hierarchically micro/nano-porous structure by using bubble template method electrodeposition of self-supporting micro-porous Ni Co P film,oxygen-free annealing for phase separation producing Ni_(3)P-Ni-Co_(2)P-Co structure,and acid etching for constructing surface nano-porous structure.The effective active sites for HER was significantly increased due to the hierarchically micro/nano-porous structure,which not only enlarged the surface roughness,but enhanced the bubble detachment by improving the hydrophilicity.Meanwhile,the HER electrolysis durability was improved benefiting from the Ni_(3)P-Co_(2)P phases with high corrosion resistance(especially in acid solution)and the self-supporting film structure without binder.Consequently,the Ni Co P-OA-AE film exhibited high HER catalytic performance,which delivered a current density of 10 m A cm^(-2)at a low overpotential of 42.9 and 39.7 m V in 1 M KOH and 0.5 M H_(2)SO_(4),respectively.It also possessed high long-term electrolysis durability,and the cell voltage of water electrolysis using self-supporting porous Ni Co P-OA-AE||Ir O_(2)-Ta_(2)O_(5) electrolyzer at 500 m A cm^(-2)for 250 h in 0.5 M H_(2)SO_(4 )is only 2.9 V.
