A two-degree-of-freedom（2-DOF） linear ultrasonic motor （USM） consists of a cylinder-shaped stator and a slider. Two bending vibration modes with orthogonality and one longitudinal vibration mode are excited in the...A two-degree-of-freedom（2-DOF） linear ultrasonic motor （USM） consists of a cylinder-shaped stator and a slider. Two bending vibration modes with orthogonality and one longitudinal vibration mode are excited in the stator by three groups of piezoelectric ceramic elements. The combinations of any one bending mode and the longitudinal mode mentioned above push the slider to move linearly in direction x or y. Some key issues for improving the motor output properties and efficiency are given. They include selection of the vibration modes, consistency of the modal frequencies, placement of the piezoelectric ceramic elements and the supporting plane, setting of pre-pressure, and influence of interfering modes.展开更多
Taking advantage of our improved gates as well as the Giorgi-Pasquale-Paganelli （GPP） nondestructive gate [Phys. Rev. A 70 （2004） 022319], the sign of any term of the initial state in the GPP model can be flipped....Taking advantage of our improved gates as well as the Giorgi-Pasquale-Paganelli （GPP） nondestructive gate [Phys. Rev. A 70 （2004） 022319], the sign of any term of the initial state in the GPP model can be flipped. The success possibility of the sign flip of odd number of terms is probabilistic （11/4）, while the success possibility of the sign flip of even number of terms is deterministic （1）.展开更多
We study non-topological, charged planar walls （Q-walls） in the context of a particle physics model with supersymmetry broken by low-energy gauge mediation. Analytical properties are derived within the fiat-potentia...We study non-topological, charged planar walls （Q-walls） in the context of a particle physics model with supersymmetry broken by low-energy gauge mediation. Analytical properties are derived within the fiat-potential approximation for the flat-direction raising potential, while a numerical study is performed using the fall two-loop supersymmetric potential. We analyze the energetics of finite-size Q-walls and compare them to Q-balls, non-topological solitons possessing spherical symmetry and arising in the same supersymmetric model. This allows us to draw a phase diagram in the charge-transverse length plane, which shows a region where Q-wall solutions are energetically favored over Q-balls. However, due to their finiteness, such finite-size Q-walls are dynamically unstable and decay into Q-balls in a time which is less than their typical scale-length.展开更多
A modal analysis method of the rotor-stator interactions in multistage compressors has been developed by LMFA. This method, based on a double modal decomposition of the flow over space and time, has been applied to nu...A modal analysis method of the rotor-stator interactions in multistage compressors has been developed by LMFA. This method, based on a double modal decomposition of the flow over space and time, has been applied to nu- merical and experimental results of the high-speed 3Y2-stage compressor CREATE based at LMFA, Lyon-France. It reveals the presence of a very strong rotor-stator interaction which completely drives the flow at casing behind all the rotors. This modal analysis method applied to an unsteady RANS simulation permits to calculate the en- ergy of the rotor-stator interactions and to plot energetic meridian maps to explain experimental results and to analyze the interaction in the whole machine.展开更多
文摘A two-degree-of-freedom（2-DOF） linear ultrasonic motor （USM） consists of a cylinder-shaped stator and a slider. Two bending vibration modes with orthogonality and one longitudinal vibration mode are excited in the stator by three groups of piezoelectric ceramic elements. The combinations of any one bending mode and the longitudinal mode mentioned above push the slider to move linearly in direction x or y. Some key issues for improving the motor output properties and efficiency are given. They include selection of the vibration modes, consistency of the modal frequencies, placement of the piezoelectric ceramic elements and the supporting plane, setting of pre-pressure, and influence of interfering modes.
基金The project supported by National Natural Science Foundation of China under Grant No. 10304022
文摘Taking advantage of our improved gates as well as the Giorgi-Pasquale-Paganelli （GPP） nondestructive gate [Phys. Rev. A 70 （2004） 022319], the sign of any term of the initial state in the GPP model can be flipped. The success possibility of the sign flip of odd number of terms is probabilistic （11/4）, while the success possibility of the sign flip of even number of terms is deterministic （1）.
文摘We study non-topological, charged planar walls （Q-walls） in the context of a particle physics model with supersymmetry broken by low-energy gauge mediation. Analytical properties are derived within the fiat-potential approximation for the flat-direction raising potential, while a numerical study is performed using the fall two-loop supersymmetric potential. We analyze the energetics of finite-size Q-walls and compare them to Q-balls, non-topological solitons possessing spherical symmetry and arising in the same supersymmetric model. This allows us to draw a phase diagram in the charge-transverse length plane, which shows a region where Q-wall solutions are energetically favored over Q-balls. However, due to their finiteness, such finite-size Q-walls are dynamically unstable and decay into Q-balls in a time which is less than their typical scale-length.
基金the CNRS and the company Snecma (SAFRAN) which support the compressor CREATE research program
文摘A modal analysis method of the rotor-stator interactions in multistage compressors has been developed by LMFA. This method, based on a double modal decomposition of the flow over space and time, has been applied to nu- merical and experimental results of the high-speed 3Y2-stage compressor CREATE based at LMFA, Lyon-France. It reveals the presence of a very strong rotor-stator interaction which completely drives the flow at casing behind all the rotors. This modal analysis method applied to an unsteady RANS simulation permits to calculate the en- ergy of the rotor-stator interactions and to plot energetic meridian maps to explain experimental results and to analyze the interaction in the whole machine.
