In this paper a practical but sufficiently accurate method of calculating transient components in short circuit currents and voltages is proposed. It enables to find the roots of the chara...In this paper a practical but sufficiently accurate method of calculating transient components in short circuit currents and voltages is proposed. It enables to find the roots of the characteristic equation of high order without forming and solving it. This method is convenient to use especially in case of complicated expansionary power systems.展开更多
We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array.By adiabatically varying the external gate voltage applied on the system,the quantum information encoded in the electron...We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array.By adiabatically varying the external gate voltage applied on the system,the quantum information encoded in the electron can be transported from one end dot to another.We numerically solve the schr dinger equation for a system with a given number of quantum dots.It is shown that this scheme is a simple and efficient protocol to coherently manipulate the population transfer under suitable gate pulses.The dependence of the energy gap and the transfer time on system parameters is analyzed and shown numerically.We also investigate the adiabatic passage in a more realistic system in the presence of inevitable fabrication imperfections.This method provides guidance for future realizations of adiabatic quantum state transfer in experiments.展开更多
The four-coil wireless power transfer(WPT)technology can effectively improve the transfer efficiency.The high efficiency,however,cannot be obtained along the whole transfer distance due to the phenomenon of frequency ...The four-coil wireless power transfer(WPT)technology can effectively improve the transfer efficiency.The high efficiency,however,cannot be obtained along the whole transfer distance due to the phenomenon of frequency splitting in the over coupled region.Aiming at this limitation,this paper presents a switchable WPT system to improve the overall efficiency by changing the number of working coils.The switching conditions for the designed system are determined based on the analysis of the transfer efficiencies of four structures,which is deduced through modeling the equivalent circuits.The simulation results well comply with the experimental results and both of them indicate that the switchable system can greatly improve the overall transfer efficiency along the whole transfer distance.The overall efficiency of the experimental system can reach above 70%at9.97 MHz without additional complexity,which is higher than any single structure system.展开更多
For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors (FETs), the influence of the ions in the solution on the electron transport has to be understood. For...For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors (FETs), the influence of the ions in the solution on the electron transport has to be understood. For this purpose we establish a simulation platform for nanowire FETs in the liquid environment by implementing the modified Poisson-Boltzmann model into Landauer transport theory. We investigate the changes of the electric potential and the transport characteristics due to the ions. The reduction of sensitivity of the sensors due to the screening effect from the electrolyte could be successfully reproduced. We also fabricated silicon nanowire Schottky-barrier FETs and our model could capture the observed reduction of the current with increasing ionic concentration. This shows that our simulation platform can be used to interpret ongoing experiments, to design nanowire FETs, and it also gives insight into controversial issues such as whether ions in the buffer solution affect the transport characteristics or not.展开更多
文摘In this paper a practical but sufficiently accurate method of calculating transient components in short circuit currents and voltages is proposed. It enables to find the roots of the characteristic equation of high order without forming and solving it. This method is convenient to use especially in case of complicated expansionary power systems.
基金support of the National Natural Science Foundation of China (Grant Nos. 10847150 and 11105086)the Shandong Provincial Natural Science Foundation (Grant Nos. ZR2009AM026 and BS2011-DX029)+1 种基金the Basic Scientific Research Project of Qingdao (Grant No.11-2-4-4-(6)-jch)the Basic Scientific Research Business Expenses of the Central University and Open Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou University (Grant No. LZUMMM2011001) for financial support
文摘We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array.By adiabatically varying the external gate voltage applied on the system,the quantum information encoded in the electron can be transported from one end dot to another.We numerically solve the schr dinger equation for a system with a given number of quantum dots.It is shown that this scheme is a simple and efficient protocol to coherently manipulate the population transfer under suitable gate pulses.The dependence of the energy gap and the transfer time on system parameters is analyzed and shown numerically.We also investigate the adiabatic passage in a more realistic system in the presence of inevitable fabrication imperfections.This method provides guidance for future realizations of adiabatic quantum state transfer in experiments.
基金supported by the National Natural Science Foundation of China(Grant No.61473281)the Self-planned Project Funded by State Key Laboratory(Grant No.2013-Z10)
文摘The four-coil wireless power transfer(WPT)technology can effectively improve the transfer efficiency.The high efficiency,however,cannot be obtained along the whole transfer distance due to the phenomenon of frequency splitting in the over coupled region.Aiming at this limitation,this paper presents a switchable WPT system to improve the overall efficiency by changing the number of working coils.The switching conditions for the designed system are determined based on the analysis of the transfer efficiencies of four structures,which is deduced through modeling the equivalent circuits.The simulation results well comply with the experimental results and both of them indicate that the switchable system can greatly improve the overall transfer efficiency along the whole transfer distance.The overall efficiency of the experimental system can reach above 70%at9.97 MHz without additional complexity,which is higher than any single structure system.
文摘For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors (FETs), the influence of the ions in the solution on the electron transport has to be understood. For this purpose we establish a simulation platform for nanowire FETs in the liquid environment by implementing the modified Poisson-Boltzmann model into Landauer transport theory. We investigate the changes of the electric potential and the transport characteristics due to the ions. The reduction of sensitivity of the sensors due to the screening effect from the electrolyte could be successfully reproduced. We also fabricated silicon nanowire Schottky-barrier FETs and our model could capture the observed reduction of the current with increasing ionic concentration. This shows that our simulation platform can be used to interpret ongoing experiments, to design nanowire FETs, and it also gives insight into controversial issues such as whether ions in the buffer solution affect the transport characteristics or not.