Discrete dislocation plasticity(DDP)calculations are carried out to investigate the response of a single crystal contacted by a rigid sinusoidal asperity under sliding loading conditions to look for causes of microstr...Discrete dislocation plasticity(DDP)calculations are carried out to investigate the response of a single crystal contacted by a rigid sinusoidal asperity under sliding loading conditions to look for causes of microstructure change in the dislocation structure.The mechanistic driver is identified as the development of lattice rotations and stored energy in the subsurface,which can be quantitatively correlated to recent tribological experimental observations.Maps of surface slip initiation and substrate permanent deformation obtained from DDP calculations for varying contact size and normal load suggest ways of optimally tailoring the interface and microstructural material properties for various frictional loads.展开更多
Coherent pulse stacking（CPS） is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy and high average power. A Z-domain model target...Coherent pulse stacking（CPS） is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy and high average power. A Z-domain model targeting the pulsed laser is assembled to describe the optical interference process. An algorithm, extracting the cavity phase and pulse phases from limited data, where only the pulse intensity is available, is developed to diagnose optical cavity resonators. We also implement the algorithm on the cascaded system of multiple optical cavities,achieving phase errors less than 1.0°（root mean square）, which could ensure the stability of CPS.展开更多
基金This work was supported by the Engineering and Physical Sciences Research Council(EPSRC)(No.EP/N025954/1).
文摘Discrete dislocation plasticity(DDP)calculations are carried out to investigate the response of a single crystal contacted by a rigid sinusoidal asperity under sliding loading conditions to look for causes of microstructure change in the dislocation structure.The mechanistic driver is identified as the development of lattice rotations and stored energy in the subsurface,which can be quantitatively correlated to recent tribological experimental observations.Maps of surface slip initiation and substrate permanent deformation obtained from DDP calculations for varying contact size and normal load suggest ways of optimally tailoring the interface and microstructural material properties for various frictional loads.
基金supported by the Director,Office of Science,Office of High Energy Physics,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231by the National Natural Science Foundation of China under Grant No.11475097
文摘Coherent pulse stacking（CPS） is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy and high average power. A Z-domain model targeting the pulsed laser is assembled to describe the optical interference process. An algorithm, extracting the cavity phase and pulse phases from limited data, where only the pulse intensity is available, is developed to diagnose optical cavity resonators. We also implement the algorithm on the cascaded system of multiple optical cavities,achieving phase errors less than 1.0°（root mean square）, which could ensure the stability of CPS.
