西方"理论运动",亦称西方"教育管理理论运动"(theory movement in educational administration),大致是在20世纪50年代初期,在美国出现的一种力图将教育管理建构在实证主义与逻辑实证主义基础之上的"管理科学&...西方"理论运动",亦称西方"教育管理理论运动"(theory movement in educational administration),大致是在20世纪50年代初期,在美国出现的一种力图将教育管理建构在实证主义与逻辑实证主义基础之上的"管理科学"运动,后遍及英、法、加、澳等国,对战后美国并整个西方教育管理理论研究发展具有里程碑的意义.本文将从"理论运动"的兴起、理论运动的假设和目标、代表人物的主要观点、理论界的评价方面加以研究,并试图从中得出对我国教育管理理论研究一些有益的启示.展开更多
In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM(1,N) model in grey system theory to predict pla...In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM(1,N) model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N) model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM(1,N) model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.展开更多
Nowadays,there are many studies conducted in the field of marine hydrodynamics which focus on two vessels traveling and floating in sufficiently close proximity to experience significant interactions.The hydrodynamic ...Nowadays,there are many studies conducted in the field of marine hydrodynamics which focus on two vessels traveling and floating in sufficiently close proximity to experience significant interactions.The hydrodynamic behavior of parallel moving ships in waves is an interesting and important topic of late.A numerical investigation has been carried out for the prediction of wave exciting forces and motion responses of parallel moving ships in regular waves.The numerical solution was based on 3D distribution technique and using the linear wave theory to determine the exciting forces and ship's motion.The speed effects have been considered in the Green function for more realistic results.The numerical computations of wave exciting forces and motion responses were carried out for a Mariner and Series 60 for the purpose of discovering different Froude numbers and different separation distances in head sea conditions.Based on the numerical computations,it was revealed that the sway,roll and yaw have a significant effect due to hydrodynamic interaction.展开更多
The electron movement based on the multi-photon nonlinear Compton scattering with the extra-intense stationary laser field is discussed by using KMR (Kroll-Morton-Rosenbluth) theory.We find that there exists only an e...The electron movement based on the multi-photon nonlinear Compton scattering with the extra-intense stationary laser field is discussed by using KMR (Kroll-Morton-Rosenbluth) theory.We find that there exists only an evolution from periodicity to non-periodicity of the un-captured electron phase orbits after the energy exchange between the electron beam and laser fields.With the increase of the absorbed photon number n by an electron, this evolution will be more and more faster, while it is rapidly decreased with the enhancement of the collision non-flexibility ξ of the electrons and photons; When the electrons are captured by the laser fields, the evolution is finished, the electrons will stably transport,and the photons dont give up the energy to these electrons.展开更多
For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. B...For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.展开更多
One of the key issues for parallel mechanism is the kinematic characteristics,especially the workspace which varies with configuration parameters.A kind of 4UPS-UPU parallel mechanism is designed and its workspace is ...One of the key issues for parallel mechanism is the kinematic characteristics,especially the workspace which varies with configuration parameters.A kind of 4UPS-UPU parallel mechanism is designed and its workspace is studied in this paper.First,the mobility of the 4UPS-UPU parallel mechanism is analyzed based on the reciprocal screw theory,and the motion and constraint screw systems of the parallel mechanism are obtained.Then the inverse kinematics is derived by the closed-form kinematics chain.The boundary search method in the polar coordinate system is presented to analyze the constant-orientation workspace of the parallel mechanism.Finally,the influence factors relevant to the workspace,such as the structural parameters and kinematics parameters are analyzed in detail.The relationship between the workspace volume and different parameters are obtained.The conclusions can be used for parameters optimization and path planning of the parallel mechanism.展开更多
A single-spin transition critical dynamics is used to investigate the three-dimensional kinetic Ising model on an anisotropic cubic lattice. We first derive the fundamental dynamical equations, and then linearize them...A single-spin transition critical dynamics is used to investigate the three-dimensional kinetic Ising model on an anisotropic cubic lattice. We first derive the fundamental dynamical equations, and then linearize them by a cutoff approximation. We obtain the approximate solutions of the local magnetization and equal-time pair correlation function in zero field. In which the axial-decoupling terms , and as higher infinitesimal quantity are ignored, where . We think that it is reasonable as the temperature of the system is very high. The result of what we obtain in this paper can go back to the one-dimensional Glauber's theory as long as .展开更多
In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied ...In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied to gauge theory of gravity. In gauge theory of gravity, based on the viewpoint of the coupling between the spin and gravitational field, an equation of motlon of the spin is deduced. In the post Newtonian approximation, it is proved that this equation gives the same result as that of the equation of parallel transport. So, in the post Newtonian approximation, gauge theory of gravity gives out the same prediction on the precession of orbiting gyroscope as that of general relativity.展开更多
In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light...In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions.展开更多
Experimental results indicate that propagation paths of cracks in geomaterials are often irregular. producing rough fracture surfaces which are fractal. A formula is derived for the fractal kinematics of crack propaga...Experimental results indicate that propagation paths of cracks in geomaterials are often irregular. producing rough fracture surfaces which are fractal. A formula is derived for the fractal kinematics of crack propagation in geomaterials. The formula correlates the dynamic and static fracture toughnesses with crack velocity, crack length and a microstructural parameter, and allows the fractal dimension to be obtained. From the equations for estimating crack velocity and fractal dimension it can be shown that the measured crack ve1ocity, Vo, should be much smaller than the fractal crack velocity, V. It can also be shown that the fractal dimension of the crack propagation path can be calculated directly from Vo and from the fracture toughness.展开更多
There is expounded the theory of"gravitational" wave propagation from the volcano crater (magma) under changing density of magma mass inside the volcano. It was revealed that while the abruptly accelerated magma m...There is expounded the theory of"gravitational" wave propagation from the volcano crater (magma) under changing density of magma mass inside the volcano. It was revealed that while the abruptly accelerated magma movement during starting period began eruption, the registered "gravitational" waves were being emitted and were propagating with the velocity greater than that of sound and seismic waves velocity. Alteration of "gravitational" waves velocity under the magma movement can be additional feature in prognosis of the start time of volcano eruption. The considered method might be effective when making up prognoses of underwater volcano eruption.展开更多
In order to understand the laws of motion for supercavitating vehicle better, simplified equations for longitudinal motion of supercavitating vehicle were derived. Then the corresponding simulation software for trajec...In order to understand the laws of motion for supercavitating vehicle better, simplified equations for longitudinal motion of supercavitating vehicle were derived. Then the corresponding simulation software for trajectory of supereavitating vehicle was programmed, by which the theoretical predicted trajectories of the supercavitating vehicle at different velocities were obtained. It was found that the predicted trajectories at low speed and without cavitation on the vehicle in theory agreed well with those in experiments, and the theoretical predicted trajectories at high speed and with supercavity on the vehicle correctly reflected the motion laws of the supercavitating vehicle. The influences of various parameters of eavitator and rudder on the underwater trajectory were compared and analyzed, which can provide a guide for the design of hydrodynamic distribution and gross parameters of the supereavitating weapons.展开更多
The theory of motion is the important section of Mr. Arne Heim's theory of visual perception. In this paper, the author focus- es on his stroboscopic theory, and at the same time, according to the motion theory of Mr...The theory of motion is the important section of Mr. Arne Heim's theory of visual perception. In this paper, the author focus- es on his stroboscopic theory, and at the same time, according to the motion theory of Mr. Arne Heim, the "Sistine Madonna" is analyzed.展开更多
In the view of the problems existing in horizontal well,such as sand depositing and cleaning difficulty of borehole,a technology with rotating jet suitable to resolution of the problems was presented.Based on liquid s...In the view of the problems existing in horizontal well,such as sand depositing and cleaning difficulty of borehole,a technology with rotating jet suitable to resolution of the problems was presented.Based on liquid solid two-phase flow theory,the analyses on the sand movement law and the swirling field influential factors were conducted.Results show that:1) With the increasing of displacement in horizontal section annulus,swirling field strength increases,and when the displacement is constant,the closer from the nozzle,the stronger the swirling field strength is;2) Head rotating speed and liquid viscosity have little influence on the swirling field strength,but the sand-carrying rate of fluid can increase by increasing liquid viscosity in a certain range;3) Rotating the string and reducing its eccentricity in annulus are conducive for sand migration in the annulus;4) The sand can be suspended and accelerated again and the swirling field strength is enhanced by the helix agitator.Hence,the research results provide the theoretical basis for the design and application of rotating jet tool.展开更多
The equations determining a resultant screw of two given screws are applied to the studies on gearing and meshing theories. A kinematical classification is proposed and meanwhile proof is given to the First Theorem of...The equations determining a resultant screw of two given screws are applied to the studies on gearing and meshing theories. A kinematical classification is proposed and meanwhile proof is given to the First Theorem of Gearing and Willis Theorem.展开更多
A systematic method is developed to studY the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge fie...A systematic method is developed to studY the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge field is obtained, which is just the traditional Schwarzschild solution. Combining the principle of gauge covariance and Newton's second law of motion, the equation of motion of a mass point in gravitational field is deduced. Based on the spherical symmetric solution of the field equation and the equation of motion of a mass point in gravitational field, we can discuss classical tests of gauge theory of gravity, including the deflection of light by the sun, the precession of the perihelia of the orbits of the inner planets and the time delay of radar echoes passing the sun. It is found that the theoretical predictions of these classical tests given by gauge theory of gravity are completely the same as those given by general relativity.展开更多
In a previous work[J.Chem.Phys.140,174105(2014)],we have shown that a mixed quantum classical(MQC)rate theory can be derived to investigate the quantum tunneling effects in the proton transfer reactions.However,the me...In a previous work[J.Chem.Phys.140,174105(2014)],we have shown that a mixed quantum classical(MQC)rate theory can be derived to investigate the quantum tunneling effects in the proton transfer reactions.However,the method is based on the high temperature approximation of the hierarchical equation of motion(HEOM)with the Debye-Drude spectral density,and results in a multistate Zusman type of equation.We now extend this theory to include quantum effects of the bath degrees of freedom.By writing the full HEOM into a multidimensional partial differential equation in phase space,we can define a new reaction coordinate,and the previous method can be generalized to the full quantum regime.The validity of the new method is demonstrated by using numerical examples,including the spin-Boson model,and the double well model for proton transfer reaction.The new method is found to resolve some key problems of the previous theory based on high temperature approximation,including possible numerical instability in long time simulation and wrong rate constant at low temperatures.展开更多
文摘西方"理论运动",亦称西方"教育管理理论运动"(theory movement in educational administration),大致是在20世纪50年代初期,在美国出现的一种力图将教育管理建构在实证主义与逻辑实证主义基础之上的"管理科学"运动,后遍及英、法、加、澳等国,对战后美国并整个西方教育管理理论研究发展具有里程碑的意义.本文将从"理论运动"的兴起、理论运动的假设和目标、代表人物的主要观点、理论界的评价方面加以研究,并试图从中得出对我国教育管理理论研究一些有益的启示.
基金Supported by the Foundation of State Key Laboratory of Autonomous Underwater Vehicle, Harbin Engineering Universitythe Fundamental Research Funds for the Central Universities (HEUCFL20101113)
文摘In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM(1,N) model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N) model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM(1,N) model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.
基金support of JASSO to conduct this research work during the author’s stay at Japan
文摘Nowadays,there are many studies conducted in the field of marine hydrodynamics which focus on two vessels traveling and floating in sufficiently close proximity to experience significant interactions.The hydrodynamic behavior of parallel moving ships in waves is an interesting and important topic of late.A numerical investigation has been carried out for the prediction of wave exciting forces and motion responses of parallel moving ships in regular waves.The numerical solution was based on 3D distribution technique and using the linear wave theory to determine the exciting forces and ship's motion.The speed effects have been considered in the Green function for more realistic results.The numerical computations of wave exciting forces and motion responses were carried out for a Mariner and Series 60 for the purpose of discovering different Froude numbers and different separation distances in head sea conditions.Based on the numerical computations,it was revealed that the sway,roll and yaw have a significant effect due to hydrodynamic interaction.
文摘The electron movement based on the multi-photon nonlinear Compton scattering with the extra-intense stationary laser field is discussed by using KMR (Kroll-Morton-Rosenbluth) theory.We find that there exists only an evolution from periodicity to non-periodicity of the un-captured electron phase orbits after the energy exchange between the electron beam and laser fields.With the increase of the absorbed photon number n by an electron, this evolution will be more and more faster, while it is rapidly decreased with the enhancement of the collision non-flexibility ξ of the electrons and photons; When the electrons are captured by the laser fields, the evolution is finished, the electrons will stably transport,and the photons dont give up the energy to these electrons.
文摘For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.
基金Supported by the National High Technology Research and Development Programme of China(No.SS2012AA041604)
文摘One of the key issues for parallel mechanism is the kinematic characteristics,especially the workspace which varies with configuration parameters.A kind of 4UPS-UPU parallel mechanism is designed and its workspace is studied in this paper.First,the mobility of the 4UPS-UPU parallel mechanism is analyzed based on the reciprocal screw theory,and the motion and constraint screw systems of the parallel mechanism are obtained.Then the inverse kinematics is derived by the closed-form kinematics chain.The boundary search method in the polar coordinate system is presented to analyze the constant-orientation workspace of the parallel mechanism.Finally,the influence factors relevant to the workspace,such as the structural parameters and kinematics parameters are analyzed in detail.The relationship between the workspace volume and different parameters are obtained.The conclusions can be used for parameters optimization and path planning of the parallel mechanism.
文摘A single-spin transition critical dynamics is used to investigate the three-dimensional kinetic Ising model on an anisotropic cubic lattice. We first derive the fundamental dynamical equations, and then linearize them by a cutoff approximation. We obtain the approximate solutions of the local magnetization and equal-time pair correlation function in zero field. In which the axial-decoupling terms , and as higher infinitesimal quantity are ignored, where . We think that it is reasonable as the temperature of the system is very high. The result of what we obtain in this paper can go back to the one-dimensional Glauber's theory as long as .
文摘In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied to gauge theory of gravity. In gauge theory of gravity, based on the viewpoint of the coupling between the spin and gravitational field, an equation of motlon of the spin is deduced. In the post Newtonian approximation, it is proved that this equation gives the same result as that of the equation of parallel transport. So, in the post Newtonian approximation, gauge theory of gravity gives out the same prediction on the precession of orbiting gyroscope as that of general relativity.
基金Supported by the National Natural Science Foundation of China under Grant No. 10875171
文摘In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions.
文摘Experimental results indicate that propagation paths of cracks in geomaterials are often irregular. producing rough fracture surfaces which are fractal. A formula is derived for the fractal kinematics of crack propagation in geomaterials. The formula correlates the dynamic and static fracture toughnesses with crack velocity, crack length and a microstructural parameter, and allows the fractal dimension to be obtained. From the equations for estimating crack velocity and fractal dimension it can be shown that the measured crack ve1ocity, Vo, should be much smaller than the fractal crack velocity, V. It can also be shown that the fractal dimension of the crack propagation path can be calculated directly from Vo and from the fracture toughness.
文摘There is expounded the theory of"gravitational" wave propagation from the volcano crater (magma) under changing density of magma mass inside the volcano. It was revealed that while the abruptly accelerated magma movement during starting period began eruption, the registered "gravitational" waves were being emitted and were propagating with the velocity greater than that of sound and seismic waves velocity. Alteration of "gravitational" waves velocity under the magma movement can be additional feature in prognosis of the start time of volcano eruption. The considered method might be effective when making up prognoses of underwater volcano eruption.
文摘In order to understand the laws of motion for supercavitating vehicle better, simplified equations for longitudinal motion of supercavitating vehicle were derived. Then the corresponding simulation software for trajectory of supereavitating vehicle was programmed, by which the theoretical predicted trajectories of the supercavitating vehicle at different velocities were obtained. It was found that the predicted trajectories at low speed and without cavitation on the vehicle in theory agreed well with those in experiments, and the theoretical predicted trajectories at high speed and with supercavity on the vehicle correctly reflected the motion laws of the supercavitating vehicle. The influences of various parameters of eavitator and rudder on the underwater trajectory were compared and analyzed, which can provide a guide for the design of hydrodynamic distribution and gross parameters of the supereavitating weapons.
文摘The theory of motion is the important section of Mr. Arne Heim's theory of visual perception. In this paper, the author focus- es on his stroboscopic theory, and at the same time, according to the motion theory of Mr. Arne Heim, the "Sistine Madonna" is analyzed.
基金Projects(51004082,51222406)supported by the National Natural Science Foundation of ChinaProject(NCET-12-1061)supported by the New Century Excellent Talents in University of ChinaProjects(12TD007,2011JQ0020)supported by Scientific Research Innovation Team Project of Sichuan and the Sichuan Youth Sci-tech Fund,China
文摘In the view of the problems existing in horizontal well,such as sand depositing and cleaning difficulty of borehole,a technology with rotating jet suitable to resolution of the problems was presented.Based on liquid solid two-phase flow theory,the analyses on the sand movement law and the swirling field influential factors were conducted.Results show that:1) With the increasing of displacement in horizontal section annulus,swirling field strength increases,and when the displacement is constant,the closer from the nozzle,the stronger the swirling field strength is;2) Head rotating speed and liquid viscosity have little influence on the swirling field strength,but the sand-carrying rate of fluid can increase by increasing liquid viscosity in a certain range;3) Rotating the string and reducing its eccentricity in annulus are conducive for sand migration in the annulus;4) The sand can be suspended and accelerated again and the swirling field strength is enhanced by the helix agitator.Hence,the research results provide the theoretical basis for the design and application of rotating jet tool.
文摘The equations determining a resultant screw of two given screws are applied to the studies on gearing and meshing theories. A kinematical classification is proposed and meanwhile proof is given to the First Theorem of Gearing and Willis Theorem.
文摘A systematic method is developed to studY the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge field is obtained, which is just the traditional Schwarzschild solution. Combining the principle of gauge covariance and Newton's second law of motion, the equation of motion of a mass point in gravitational field is deduced. Based on the spherical symmetric solution of the field equation and the equation of motion of a mass point in gravitational field, we can discuss classical tests of gauge theory of gravity, including the deflection of light by the sun, the precession of the perihelia of the orbits of the inner planets and the time delay of radar echoes passing the sun. It is found that the theoretical predictions of these classical tests given by gauge theory of gravity are completely the same as those given by general relativity.
基金supported by the National Natural Science Foundation of China(No.21933011)the K.C.Wong Education Foundation。
文摘In a previous work[J.Chem.Phys.140,174105(2014)],we have shown that a mixed quantum classical(MQC)rate theory can be derived to investigate the quantum tunneling effects in the proton transfer reactions.However,the method is based on the high temperature approximation of the hierarchical equation of motion(HEOM)with the Debye-Drude spectral density,and results in a multistate Zusman type of equation.We now extend this theory to include quantum effects of the bath degrees of freedom.By writing the full HEOM into a multidimensional partial differential equation in phase space,we can define a new reaction coordinate,and the previous method can be generalized to the full quantum regime.The validity of the new method is demonstrated by using numerical examples,including the spin-Boson model,and the double well model for proton transfer reaction.The new method is found to resolve some key problems of the previous theory based on high temperature approximation,including possible numerical instability in long time simulation and wrong rate constant at low temperatures.