The transformation process of an m-DOF free-floating robot from one static state to a different static state has m degrees of freedom.The proposed approach of these transformations util-izes a series of single-DOF tra...The transformation process of an m-DOF free-floating robot from one static state to a different static state has m degrees of freedom.The proposed approach of these transformations util-izes a series of single-DOF transformation processes as an alternative to the m-DOF transformation process.Two static state transformation processes are studied in detail.First,a single-DOF transformation process is established using a newly defined concept,referred to as transformation planning,and the definite integral of conservation of angular momentum.Second,the governing equation of the single-DOF transformation process is established using the dynamic equations of motion of the robot.This allows the joint torques to be computed to effect the state transformation.Finally,an extension of the single-DOF transformation process is proposed to extend the application of this proposed transformation methodology to create a transformation net which allows the reconfiguration of a robot from one state to many other possible states.展开更多
It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analy...It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analysis of the WPCS by employing the PV curve and model analysis is proposed to reveal the voltage stability influence from different aspects. The PV curve is utilized to trace and indicate the voltage collapse point of the WPCS when the small disturbance of wind power is increased gradually. Then the steady state voltage instability modes of the WPCS are analyzed by calculating the bus participation factors of the minimum eigenvalue model at the collapse point. The simulation results of an actual WPCS in North China show that the static state voltage instability mode of the WPCS is closely related to the operating features and control strategies of different reactive power sources. In addition, the implementation of the doubly-fed induction generator wind turbine generator voltage control is beneficial to improve the WPCS voltage stability.展开更多
On the basis of Karman’s theory of thin plates with large deflection, the Boltzmann law on linear viscoelastic materials and the mathematical model of dynamic analysis on viscoelastic thin plates, a set of nonlinear ...On the basis of Karman’s theory of thin plates with large deflection, the Boltzmann law on linear viscoelastic materials and the mathematical model of dynamic analysis on viscoelastic thin plates, a set of nonlinear integro partial differential equations is first presented by means of a structural function introduced in this paper. Then, by using the Galerkin technique in spatial field and a backward difference scheme in temporal field, the set of nonlinear integro partial differential equations reduces to a system of nonlinear algebraic equations. After solving the algebraic equations, the buckling behavior and multiple equilibrium states can be obtained.展开更多
The thermodynamic quantities for the gases of massless particles with spin s = 1/2,1,3/2,2 around static spherical black holes are investigated by using the brick-wall method.The appearance of the spin-dependent suble...The thermodynamic quantities for the gases of massless particles with spin s = 1/2,1,3/2,2 around static spherical black holes are investigated by using the brick-wall method.The appearance of the spin-dependent subleading terms is demonstrated and the terms are shown to contain not only the linear and quadratic terms of the spins but also a zero-power term of the spins.展开更多
We propose a scheme to generate atomic cluster states of arbitrary configuration in the cavity quantumelectrodynamics (QED) system.The process is achieved via adiabatic evolution of dark states,which only requiresadia...We propose a scheme to generate atomic cluster states of arbitrary configuration in the cavity quantumelectrodynamics (QED) system.The process is achieved via adiabatic evolution of dark states,which only requiresadiabatically increasing or decreasing Rabi frequencies of laser.Thus it allows the robust implementation of entanglementagainst certain types of errors.Our scheme is relatively decoherence-free in the sense that excited atomic states are neverpopulated and excited cavity photon states can be made negligible in certain conditions.展开更多
The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphrag...The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphragm selection and rippled design, laser welding, silicon oil infilling, isolation and other techniques used in sensor packaging, which can affect the performance of the sensor. By adopting stainless steel diaphragm and high-temperature silicon oil as isolation materials, not only the encapsulation of the sensor is as small as 15 mm in diameter and under 1 mA drive, its full range output is 72 mV and zero stability is 0.48% F.S/mon, but also the reliability of the sensor is improved and its application is widely broadened.展开更多
Based on the character of the internal force distribution of the statically indeterminate truss, the elements stresses were changed by adjusting the length of bars to increase load capacity of structure. The efficienc...Based on the character of the internal force distribution of the statically indeterminate truss, the elements stresses were changed by adjusting the length of bars to increase load capacity of structure. The efficiency of the method is illustrated by several examples.展开更多
文摘The transformation process of an m-DOF free-floating robot from one static state to a different static state has m degrees of freedom.The proposed approach of these transformations util-izes a series of single-DOF transformation processes as an alternative to the m-DOF transformation process.Two static state transformation processes are studied in detail.First,a single-DOF transformation process is established using a newly defined concept,referred to as transformation planning,and the definite integral of conservation of angular momentum.Second,the governing equation of the single-DOF transformation process is established using the dynamic equations of motion of the robot.This allows the joint torques to be computed to effect the state transformation.Finally,an extension of the single-DOF transformation process is proposed to extend the application of this proposed transformation methodology to create a transformation net which allows the reconfiguration of a robot from one state to many other possible states.
文摘It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analysis of the WPCS by employing the PV curve and model analysis is proposed to reveal the voltage stability influence from different aspects. The PV curve is utilized to trace and indicate the voltage collapse point of the WPCS when the small disturbance of wind power is increased gradually. Then the steady state voltage instability modes of the WPCS are analyzed by calculating the bus participation factors of the minimum eigenvalue model at the collapse point. The simulation results of an actual WPCS in North China show that the static state voltage instability mode of the WPCS is closely related to the operating features and control strategies of different reactive power sources. In addition, the implementation of the doubly-fed induction generator wind turbine generator voltage control is beneficial to improve the WPCS voltage stability.
文摘On the basis of Karman’s theory of thin plates with large deflection, the Boltzmann law on linear viscoelastic materials and the mathematical model of dynamic analysis on viscoelastic thin plates, a set of nonlinear integro partial differential equations is first presented by means of a structural function introduced in this paper. Then, by using the Galerkin technique in spatial field and a backward difference scheme in temporal field, the set of nonlinear integro partial differential equations reduces to a system of nonlinear algebraic equations. After solving the algebraic equations, the buckling behavior and multiple equilibrium states can be obtained.
文摘The thermodynamic quantities for the gases of massless particles with spin s = 1/2,1,3/2,2 around static spherical black holes are investigated by using the brick-wall method.The appearance of the spin-dependent subleading terms is demonstrated and the terms are shown to contain not only the linear and quadratic terms of the spins but also a zero-power term of the spins.
基金National Natural Science Foundation of China under Grant No.1050402
文摘We propose a scheme to generate atomic cluster states of arbitrary configuration in the cavity quantumelectrodynamics (QED) system.The process is achieved via adiabatic evolution of dark states,which only requiresadiabatically increasing or decreasing Rabi frequencies of laser.Thus it allows the robust implementation of entanglementagainst certain types of errors.Our scheme is relatively decoherence-free in the sense that excited atomic states are neverpopulated and excited cavity photon states can be made negligible in certain conditions.
文摘The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphragm selection and rippled design, laser welding, silicon oil infilling, isolation and other techniques used in sensor packaging, which can affect the performance of the sensor. By adopting stainless steel diaphragm and high-temperature silicon oil as isolation materials, not only the encapsulation of the sensor is as small as 15 mm in diameter and under 1 mA drive, its full range output is 72 mV and zero stability is 0.48% F.S/mon, but also the reliability of the sensor is improved and its application is widely broadened.
文摘Based on the character of the internal force distribution of the statically indeterminate truss, the elements stresses were changed by adjusting the length of bars to increase load capacity of structure. The efficiency of the method is illustrated by several examples.
