There is a gr eat interest in obtaining epitaxial α″ nitride phase of iron because of their special ferromagnetic properties. α″ Fe 16 N 2 thin films have been prep ared by facing target sputtering (FTS) onto NaCl...There is a gr eat interest in obtaining epitaxial α″ nitride phase of iron because of their special ferromagnetic properties. α″ Fe 16 N 2 thin films have been prep ared by facing target sputtering (FTS) onto NaCl (001) substrates in a mixture of argon(Ar) and N 2 gases. The base pressure was 6×10 -5 Pa. During sput tering, the partial pressures of Ar and N 2 gases were kept constant at 0.3 Pa and 0.05 Pa respectively. The deposition rate was about 0.2 nm/s. The substrate temperature was held at about 100 ℃. Annealing of the films was sequentially ca rried out at 150 ℃ for 1 h in vacuum ( at least 10 -4 Pa ) to obtain α″ phase. Transmission electron microscope (TEM) observations and X ray diffract ion (XRD) patterns showed that the α″ Fe 16 N 2 epitaxially grew on the NaCl substrates. It was found that the arrangement of the SAD patterns exhibits perfect symmetries.By using super lattice reflections, the lattice constants a=b=(5.71±0.02)×10 -1 nm and c=(6.30±0.04) ×10 -1 nm of the α″ phase with a body centered tetragonal (BCT) structu re were determined, which was very close to the results obtained by Jack (a=b= 5.72×10 -1 nm, c= 6.29×10 -1 nm). The X ray diffraction patterns and the selected area diffraction patterns showed t hat α″ Fe 16 N 2 epitaxially grew on the NaCl (001) substrate with orien tation relationships α″ Fe 16 N 2 (001) ‖NaCl (001),α″ Fe 16 N 2 ‖NaCl .展开更多
The layered control architecture is designed for the need of the multirobot intelligent team formation.There are three levels:the cooperation task level,the coordination behavior level and the action planning level.Th...The layered control architecture is designed for the need of the multirobot intelligent team formation.There are three levels:the cooperation task level,the coordination behavior level and the action planning level.The cooperation task level uses the potential grid method,which improves the safety of the path and reduces the calculation complexity.The coordination behavior level uses the reinforcement learning which can strengthen the robots’ intelligence.The action planning level uses the fuzzy planning methods to realize the action matching.The communication model transfers the message in different level.This architecture shows not only the independence and the intelligence of the single robot but also the cooperation and the coordination among the robots.In each level,the task is distributed reasonably and clearly.Finally the feasibility of the architecture is verified further in the simulation of the experiment.The expansibility of the architecture is good and the architecture can be used in the similar system.展开更多
文摘There is a gr eat interest in obtaining epitaxial α″ nitride phase of iron because of their special ferromagnetic properties. α″ Fe 16 N 2 thin films have been prep ared by facing target sputtering (FTS) onto NaCl (001) substrates in a mixture of argon(Ar) and N 2 gases. The base pressure was 6×10 -5 Pa. During sput tering, the partial pressures of Ar and N 2 gases were kept constant at 0.3 Pa and 0.05 Pa respectively. The deposition rate was about 0.2 nm/s. The substrate temperature was held at about 100 ℃. Annealing of the films was sequentially ca rried out at 150 ℃ for 1 h in vacuum ( at least 10 -4 Pa ) to obtain α″ phase. Transmission electron microscope (TEM) observations and X ray diffract ion (XRD) patterns showed that the α″ Fe 16 N 2 epitaxially grew on the NaCl substrates. It was found that the arrangement of the SAD patterns exhibits perfect symmetries.By using super lattice reflections, the lattice constants a=b=(5.71±0.02)×10 -1 nm and c=(6.30±0.04) ×10 -1 nm of the α″ phase with a body centered tetragonal (BCT) structu re were determined, which was very close to the results obtained by Jack (a=b= 5.72×10 -1 nm, c= 6.29×10 -1 nm). The X ray diffraction patterns and the selected area diffraction patterns showed t hat α″ Fe 16 N 2 epitaxially grew on the NaCl (001) substrate with orien tation relationships α″ Fe 16 N 2 (001) ‖NaCl (001),α″ Fe 16 N 2 ‖NaCl .
基金Sponsored by the Scientific Research Foundation of Beijing Normal University and the Grants from the National Postdocteral Foundation of China.
文摘The layered control architecture is designed for the need of the multirobot intelligent team formation.There are three levels:the cooperation task level,the coordination behavior level and the action planning level.The cooperation task level uses the potential grid method,which improves the safety of the path and reduces the calculation complexity.The coordination behavior level uses the reinforcement learning which can strengthen the robots’ intelligence.The action planning level uses the fuzzy planning methods to realize the action matching.The communication model transfers the message in different level.This architecture shows not only the independence and the intelligence of the single robot but also the cooperation and the coordination among the robots.In each level,the task is distributed reasonably and clearly.Finally the feasibility of the architecture is verified further in the simulation of the experiment.The expansibility of the architecture is good and the architecture can be used in the similar system.
