We investigate the effect of Rashba spin-orbit coupling(RSOC)on photoconductivities of rectified currents in monolayer graphene with exchange field and sublattice potential.The system shows that the photoconductivitie...We investigate the effect of Rashba spin-orbit coupling(RSOC)on photoconductivities of rectified currents in monolayer graphene with exchange field and sublattice potential.The system shows that the photoconductivities of resonant shift and injection current contributions are nonzero,while the photoconductivities of non-resonant shift current contribution are zero.We find that the RSOC induces a warping term,which leads to the nonzero rectified currents.Moreover,the photoconductivities of resonant injection(shift)current contribution are(not)related to the relaxation rate.The similar behavior can be found in other Dirac materials,and our findings provide a way to tune the nonlinear transport properties of Dirac materials.展开更多
A novel theory of the commutating process of half/bridge thyristor are welding inverter is presented. According to the characteristic of its typical primary current pulse, a commutating process can be divided into th...A novel theory of the commutating process of half/bridge thyristor are welding inverter is presented. According to the characteristic of its typical primary current pulse, a commutating process can be divided into three stages. ie.. front-edge wave-head stage and back-edge stage.The equivalent circuits of each stage are presented respectively. For wave-head stage, the differential equation about the voltage across commutating capacitor has been set up with the initial condition of nonzero-current and nonzero-voltage. and its solutions are completely in accord with the practically measured waveforms. For front and back edge stages, the theory of current shifting on constant magnetic condition is introduced. The process, in which the inverse voltage across commutating capacitor is formed, and the rule, according to which the inverse voltage varies.are discussed. In addition. each. special operating state is studied carefully and a reasonable design state is determined. By T-type equivalent circuit in the design. state. the fundamental formulas for accurate engineering design are derived. Finally. two design cases are given.展开更多
Half-bridge circuit is taken as example, the physical essential of current pulse front edge and back edge in PWM of PFM converter is analyzed. The appearance of varying current-source or transfor- mation from voltage-...Half-bridge circuit is taken as example, the physical essential of current pulse front edge and back edge in PWM of PFM converter is analyzed. The appearance of varying current-source or transfor- mation from voltage-source into current-source in primary of converter is necessary condition for forming front and back edges. Through synchrenously varying of primary current and secondary current , and current shifting between two secondary windings in constant magnetic condition, transformation of basic Stages is realized.展开更多
基金Project supported by the Shandong Province Natural Science Foundation(Grant No.ZR2021MF077)。
文摘We investigate the effect of Rashba spin-orbit coupling(RSOC)on photoconductivities of rectified currents in monolayer graphene with exchange field and sublattice potential.The system shows that the photoconductivities of resonant shift and injection current contributions are nonzero,while the photoconductivities of non-resonant shift current contribution are zero.We find that the RSOC induces a warping term,which leads to the nonzero rectified currents.Moreover,the photoconductivities of resonant injection(shift)current contribution are(not)related to the relaxation rate.The similar behavior can be found in other Dirac materials,and our findings provide a way to tune the nonlinear transport properties of Dirac materials.
文摘A novel theory of the commutating process of half/bridge thyristor are welding inverter is presented. According to the characteristic of its typical primary current pulse, a commutating process can be divided into three stages. ie.. front-edge wave-head stage and back-edge stage.The equivalent circuits of each stage are presented respectively. For wave-head stage, the differential equation about the voltage across commutating capacitor has been set up with the initial condition of nonzero-current and nonzero-voltage. and its solutions are completely in accord with the practically measured waveforms. For front and back edge stages, the theory of current shifting on constant magnetic condition is introduced. The process, in which the inverse voltage across commutating capacitor is formed, and the rule, according to which the inverse voltage varies.are discussed. In addition. each. special operating state is studied carefully and a reasonable design state is determined. By T-type equivalent circuit in the design. state. the fundamental formulas for accurate engineering design are derived. Finally. two design cases are given.
文摘Half-bridge circuit is taken as example, the physical essential of current pulse front edge and back edge in PWM of PFM converter is analyzed. The appearance of varying current-source or transfor- mation from voltage-source into current-source in primary of converter is necessary condition for forming front and back edges. Through synchrenously varying of primary current and secondary current , and current shifting between two secondary windings in constant magnetic condition, transformation of basic Stages is realized.
