From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake like mobile mechanism. On the hypothesis of the existing non holonomic constraints on the robot kinematics, we set up the relation...From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake like mobile mechanism. On the hypothesis of the existing non holonomic constraints on the robot kinematics, we set up the relationship among the kinetic control parameters in the snake like movement using Lie group and Lie algebra of the principle fiber bundle and provide some theoretical control methods to realize the snake like locomotion.展开更多
The significance of quadrupole gravitational force is discussed for test mass in equivalence principle (EP), and the angular moment acting on a cylindrically symmetrical body due to quadrupole force is calculated, whi...The significance of quadrupole gravitational force is discussed for test mass in equivalence principle (EP), and the angular moment acting on a cylindrically symmetrical body due to quadrupole force is calculated, which will result in nutational oscillatory effect. The oscillations contain a perturbation with the same frequency of EP violation signal, which is mitigated by two different methods as in Galileo Galilei (GG) mission and μSCOPE. In GG the sensor for readout is sensitive to differential forces in the orbital plane perpendicular to spin axis of test cylinders. In order to mitigate the nutational oscillatory effect, test mass should be rapidly rotated with the spin axis. However, in μSCOPE, the readout sensitive axis is the symmetry axis in the orbital plane. This nutational oscillation will produce a second order effect in the rotation amplitude at twice the signal frequency, and could be subtracted easily, too.展开更多
In this study, we report the experimental reali-zation of seven-qubit Deutsch-Jozsa (D-J) algorithm and controlled phase-shift gates with improved precision using liquid state nuclear magnetic resonance (NMR). Theexpe...In this study, we report the experimental reali-zation of seven-qubit Deutsch-Jozsa (D-J) algorithm and controlled phase-shift gates with improved precision using liquid state nuclear magnetic resonance (NMR). Theexperimental results have shown that transformations Uf in the seven-qubit D-J algorithm have been implemented with different pulse sequences, and whether f is constant orbalanced is determined by using only a single function call(Uf). Furthermore, we propose an experimental method tomeasure and correct the error in the controlled phase-shift gate that is simple and feasible in experiments, and can have precise phase shifts. These may offer the possibility ofsurmounting the difficulties of low signal-to-noise ratio(SNR) in multi-qubit NMR quantum computers, morecomplicated experimental techniques, and the increase ofgate errors due to using a large number of imperfect selec-tive pulses. These are also applied to more complicated quantum algorithms with more qubits, such as quantumFourier transformation and Shor抯 algorithm.展开更多
文摘From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake like mobile mechanism. On the hypothesis of the existing non holonomic constraints on the robot kinematics, we set up the relationship among the kinetic control parameters in the snake like movement using Lie group and Lie algebra of the principle fiber bundle and provide some theoretical control methods to realize the snake like locomotion.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10205005 and 10121503
文摘The significance of quadrupole gravitational force is discussed for test mass in equivalence principle (EP), and the angular moment acting on a cylindrically symmetrical body due to quadrupole force is calculated, which will result in nutational oscillatory effect. The oscillations contain a perturbation with the same frequency of EP violation signal, which is mitigated by two different methods as in Galileo Galilei (GG) mission and μSCOPE. In GG the sensor for readout is sensitive to differential forces in the orbital plane perpendicular to spin axis of test cylinders. In order to mitigate the nutational oscillatory effect, test mass should be rapidly rotated with the spin axis. However, in μSCOPE, the readout sensitive axis is the symmetry axis in the orbital plane. This nutational oscillation will produce a second order effect in the rotation amplitude at twice the signal frequency, and could be subtracted easily, too.
基金supported by the National Natural Science Foundation of China(Grant No.19874073)the National Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KJCX2-W1)
文摘In this study, we report the experimental reali-zation of seven-qubit Deutsch-Jozsa (D-J) algorithm and controlled phase-shift gates with improved precision using liquid state nuclear magnetic resonance (NMR). Theexperimental results have shown that transformations Uf in the seven-qubit D-J algorithm have been implemented with different pulse sequences, and whether f is constant orbalanced is determined by using only a single function call(Uf). Furthermore, we propose an experimental method tomeasure and correct the error in the controlled phase-shift gate that is simple and feasible in experiments, and can have precise phase shifts. These may offer the possibility ofsurmounting the difficulties of low signal-to-noise ratio(SNR) in multi-qubit NMR quantum computers, morecomplicated experimental techniques, and the increase ofgate errors due to using a large number of imperfect selec-tive pulses. These are also applied to more complicated quantum algorithms with more qubits, such as quantumFourier transformation and Shor抯 algorithm.
