In this paper, we evaluate the general solutions for plane-symmetric thick domain walls in Lyra geometry in presence of bulk viscous fluid. Expressions for the energy density and pressure of domain walls are derived i...In this paper, we evaluate the general solutions for plane-symmetric thick domain walls in Lyra geometry in presence of bulk viscous fluid. Expressions for the energy density and pressure of domain walls are derived in both cases of uniform and time varying displacement field β. Some physical consequences of the models are also given. Finally, the geodesic equations and acceleration of the test particle are discussed.展开更多
After people or vehicles press, piezoelectric ceramics can send a weak and unstable alternating current. According to this characteristic, we made feet pressing energy collection and utilization device based on piezoe...After people or vehicles press, piezoelectric ceramics can send a weak and unstable alternating current. According to this characteristic, we made feet pressing energy collection and utilization device based on piezoelectric ceramics. The two parts of this device includes energy storage and utilization. In terms of storage, the energy collection module, can deposit AC sent by piezoelectric ceramics in the super capacitor after rectification. In terms of utilization of energy, the device achieve a variety of usage： through the USB interface, it can supply power for different equipments, replace the mobile station of train stations and realize the function of saving the electricity as the night corridor induction lamp, combined with vibration module design and programmable timer. The whole structure is supported by an acrylic plate, which saves cost and have good durability. This device implements the storage and usage of idle feet pressing energy. In conclusion, it is helpful to provide a new idea for people＇ s low carbon lives and has a quite broad application prospect.展开更多
An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in t...An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in the dynamic equations of SM buthad no effect on the energy balance equation of the closed loop.PBC,combined withadaptive control schemes,not only preserved the advantages of PBC such as nonexistenceof singularity,but also rejected the flux and speed tracking error caused by statorand rotor resistance variation.The rotor currents of SM were estimated via a state observer.This algorithm simplified the control structure and enhanced the robustness of thecontrol system.The feasibility and effectiveness were confirmed by experimental resultsbased on dSPACE.展开更多
The study of the energy localization in f(R)theories of gravity has attracted much interest in recent years.In this paper,the vacuum solutions of the modified field equations for a power model of plane symmetric metri...The study of the energy localization in f(R)theories of gravity has attracted much interest in recent years.In this paper,the vacuum solutions of the modified field equations for a power model of plane symmetric metric are studied in metric f(R)gravity with the assumption of constant Ricci scalar.Next,we determine the energy-momentum complexes in f(R)theories of gravity for this spacetime for some important models.We also show that these models satisfy the stability and constant curvature conditions.展开更多
In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array （FPGA） an...In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array （FPGA） and digital signal processor （DSP） were introduced. The performance of the digital constant fraction discrimination （dCFD） platform was experimentally tested with Agilent 80 MHz function/arbitrary waveform generator and LaC13：Ce3＋ scintillator detector for 22Na positron annihilation gamma spectroscopy. The amplitude and time information of ＂/photon was online obtained. The energy resolution could be 5.525% and the timing resolution 293.75 ps, the system error estimation of dCFD approach was also studied. The results showed that this spectrometer achieved a timing resolution close to that of traditional CFD timing resolution with a more sim- plified system structure.展开更多
文摘In this paper, we evaluate the general solutions for plane-symmetric thick domain walls in Lyra geometry in presence of bulk viscous fluid. Expressions for the energy density and pressure of domain walls are derived in both cases of uniform and time varying displacement field β. Some physical consequences of the models are also given. Finally, the geodesic equations and acceleration of the test particle are discussed.
文摘After people or vehicles press, piezoelectric ceramics can send a weak and unstable alternating current. According to this characteristic, we made feet pressing energy collection and utilization device based on piezoelectric ceramics. The two parts of this device includes energy storage and utilization. In terms of storage, the energy collection module, can deposit AC sent by piezoelectric ceramics in the super capacitor after rectification. In terms of utilization of energy, the device achieve a variety of usage： through the USB interface, it can supply power for different equipments, replace the mobile station of train stations and realize the function of saving the electricity as the night corridor induction lamp, combined with vibration module design and programmable timer. The whole structure is supported by an acrylic plate, which saves cost and have good durability. This device implements the storage and usage of idle feet pressing energy. In conclusion, it is helpful to provide a new idea for people＇ s low carbon lives and has a quite broad application prospect.
基金Supported by the National Basic Research Program of China(973 Program)(2005CB221505)the Special Scientific Research Foundation for Doctoral Subject of Colleges and Universities in China(20050248058)
文摘An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in the dynamic equations of SM buthad no effect on the energy balance equation of the closed loop.PBC,combined withadaptive control schemes,not only preserved the advantages of PBC such as nonexistenceof singularity,but also rejected the flux and speed tracking error caused by statorand rotor resistance variation.The rotor currents of SM were estimated via a state observer.This algorithm simplified the control structure and enhanced the robustness of thecontrol system.The feasibility and effectiveness were confirmed by experimental resultsbased on dSPACE.
基金Supported in part by Islamic Azad University-Kashan Branch
文摘The study of the energy localization in f(R)theories of gravity has attracted much interest in recent years.In this paper,the vacuum solutions of the modified field equations for a power model of plane symmetric metric are studied in metric f(R)gravity with the assumption of constant Ricci scalar.Next,we determine the energy-momentum complexes in f(R)theories of gravity for this spacetime for some important models.We also show that these models satisfy the stability and constant curvature conditions.
基金supported by the National Natural Science Foundation of China (Grant No. 10975132)
文摘In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array （FPGA） and digital signal processor （DSP） were introduced. The performance of the digital constant fraction discrimination （dCFD） platform was experimentally tested with Agilent 80 MHz function/arbitrary waveform generator and LaC13：Ce3＋ scintillator detector for 22Na positron annihilation gamma spectroscopy. The amplitude and time information of ＂/photon was online obtained. The energy resolution could be 5.525% and the timing resolution 293.75 ps, the system error estimation of dCFD approach was also studied. The results showed that this spectrometer achieved a timing resolution close to that of traditional CFD timing resolution with a more sim- plified system structure.
