Polycrystalline diamond films have been synthesized on various substrates by hot filament CVD from the mixture gases of methane and hydrogen. The interface layers between CVD diamond films and substrates have been inv...Polycrystalline diamond films have been synthesized on various substrates by hot filament CVD from the mixture gases of methane and hydrogen. The interface layers between CVD diamond films and substrates have been investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In addition, visible luminescence between 2.0～3.5eV of undoped and boron-doped CVD diamond films has also been studied by cathodoluminescence.展开更多
The (100) texture of solidified fcc metals, caused by the preferential (100) dendrite growth, could be closeIy related to solid/melt interfaces which behave differently along different crystallographic orientation. Th...The (100) texture of solidified fcc metals, caused by the preferential (100) dendrite growth, could be closeIy related to solid/melt interfaces which behave differently along different crystallographic orientation. The stability and roughness of {111} and {100} solid/melt interfaces of fcc metals were investigated using a modified Temkin multi-layer model. It is demonstrated that {100}crystal/melt interface is more unstable and rougher than {111} interface. The effect of the stability of crystal/melt interface on the (100) texture formation in solidified fcc metals has been analysed and discussed.展开更多
Nonlinear reflection of SV shear wave at the isotropic solid-solid interfaces is experimentally studied. The reflected second harmonic SV shear wave is measured for glass-air,glass-iron, copper and aluminum interfaces...Nonlinear reflection of SV shear wave at the isotropic solid-solid interfaces is experimentally studied. The reflected second harmonic SV shear wave is measured for glass-air,glass-iron, copper and aluminum interfaces. The relation of nonlinear reflective coefficient with the incident angle and linear as well as nonlinear characteristics of the materials is thoroughly investigated. Comparison of the experiment with the theory gives qualitatively agreement.展开更多
Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts ...Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts design does.Herein the consumption behavior of an individual oxygen bubble on Pt foils with different wettabilities during ORR was tracked by a real-time approach to reveal whether the surface wettability of electrode can influence the consumption dynamics and determine the reaction reactive zones of oxygen bubble consumption.The oxygen bubble underwent a "constant contact angle"dominant consumption model on aerophobic Pt foil,while an initial "constant radius"and the subsequent"constant contact angle"oxygen consumption models were observed on aero philic Pt foil.Results here demonstrated that the current was proportional to the bottom contact area,rather than the three-phase contact line of the bubbles according to the fitting curves between individual bubble current and the consumption behavior parameters.This study highlights the important role of the gas-solid interface in influencing the efficiency of gas consumption electrochemical reactions,which shall benefit the understanding of reaction kinetics and the rational design of electrocatalysts.展开更多
基金This work is supported by the National Natural Science Foundation of China.
文摘Polycrystalline diamond films have been synthesized on various substrates by hot filament CVD from the mixture gases of methane and hydrogen. The interface layers between CVD diamond films and substrates have been investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In addition, visible luminescence between 2.0～3.5eV of undoped and boron-doped CVD diamond films has also been studied by cathodoluminescence.
文摘The (100) texture of solidified fcc metals, caused by the preferential (100) dendrite growth, could be closeIy related to solid/melt interfaces which behave differently along different crystallographic orientation. The stability and roughness of {111} and {100} solid/melt interfaces of fcc metals were investigated using a modified Temkin multi-layer model. It is demonstrated that {100}crystal/melt interface is more unstable and rougher than {111} interface. The effect of the stability of crystal/melt interface on the (100) texture formation in solidified fcc metals has been analysed and discussed.
文摘Nonlinear reflection of SV shear wave at the isotropic solid-solid interfaces is experimentally studied. The reflected second harmonic SV shear wave is measured for glass-air,glass-iron, copper and aluminum interfaces. The relation of nonlinear reflective coefficient with the incident angle and linear as well as nonlinear characteristics of the materials is thoroughly investigated. Comparison of the experiment with the theory gives qualitatively agreement.
基金the National Natural Science Foundation of China(Nos.21675007,21676015,21520102002,91622116)the National Key Research and Development Project of China(Nos.2018YFB1502401,2018YFA0702002),the Royal Society and the Newton Fund Through the Newton Advanced Fellowship Award(No.NAF/R1/191294)+2 种基金the Program for Changjiang Scholars and Innovation Research Team in the University,China(No.IRT1205)Fundamental Research Funds for the Central Universities of Chinathe Long-term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China。
文摘Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts design does.Herein the consumption behavior of an individual oxygen bubble on Pt foils with different wettabilities during ORR was tracked by a real-time approach to reveal whether the surface wettability of electrode can influence the consumption dynamics and determine the reaction reactive zones of oxygen bubble consumption.The oxygen bubble underwent a "constant contact angle"dominant consumption model on aerophobic Pt foil,while an initial "constant radius"and the subsequent"constant contact angle"oxygen consumption models were observed on aero philic Pt foil.Results here demonstrated that the current was proportional to the bottom contact area,rather than the three-phase contact line of the bubbles according to the fitting curves between individual bubble current and the consumption behavior parameters.This study highlights the important role of the gas-solid interface in influencing the efficiency of gas consumption electrochemical reactions,which shall benefit the understanding of reaction kinetics and the rational design of electrocatalysts.
