The solid-state reduction kinetics of pre-oxidized vanadium-titanium magnetite concentrate was studied. The phase and microstructure of the reduction product were characterized by XRD, SEM and EDS methods, based on wh...The solid-state reduction kinetics of pre-oxidized vanadium-titanium magnetite concentrate was studied. The phase and microstructure of the reduction product were characterized by XRD, SEM and EDS methods, based on which the mechanism of the solid-state reduction was investigated. The results showed that using coal as reductant at 950-1100 °C, the solid-state reduction of the pre-oxidized vanadium-titanium magnetite concentrate was controlled by interface chemical reaction and the apparent activation energy was 67.719 k J/mol. The mineral phase transformation during the reduction process can be described as follows： pre-oxidized vanadium-titanium magnetite concentrate → ulvospinel → ilmenite → Fe Ti2O5 →（FenTi1-n）Ti2O5. M3O5-type（M can be Fe, Ti, Mg, Mn, etc） solid solutions would be formed during the reduction process of the pre-oxidized vanadium-titanium magnetite concentrate at 1050 °C for 60 min. The poor reducibility of iron in M3O5 solid solutions is the main reason to limit the reduction property of pre-oxidized vanadium-titanium magnetite concentrate.展开更多
In this paper, with the non-salient pole permanent magnet linear synchronous motor (PMLSM)being cited, by using Fourier transform method and "slot-by-slot", "pole -by-pole" current approach, a 3D e...In this paper, with the non-salient pole permanent magnet linear synchronous motor (PMLSM)being cited, by using Fourier transform method and "slot-by-slot", "pole -by-pole" current approach, a 3D electromagnetic field model of PMLSM is established. Special attention is paid to its structure and the influence of longitudinal and transverse end effect. The distribution of electromagnetic field of PMLSM can be obtained directly and promptly by using FFT algorithm. It can also be used for the analysis of other LSM.展开更多
In this work,the solidification of liquid iron with or without external magnetic field was investigated by using two molecular dynamics methods,namely direct cooling and two-phase simulation.The influence of external ...In this work,the solidification of liquid iron with or without external magnetic field was investigated by using two molecular dynamics methods,namely direct cooling and two-phase simulation.The influence of external magnetic field on the solidification is characterized by the critical temperature and radial distribution functions.Our computational results show that under external magnetic field,the solidification point tends to decrease significantly.By further analyzing the diffusion coefficients and viscosity,we attribute the effect to the stronger fluctuation of liquid iron atoms driven by the external magnetic field.展开更多
The internal energy and specific heat of a Heisenberg ferro- antiferromagnetic double-layer system are studied by using spin-wave theory and the retarded Green function method at low temperatures. Numerical results sh...The internal energy and specific heat of a Heisenberg ferro- antiferromagnetic double-layer system are studied by using spin-wave theory and the retarded Green function method at low temperatures. Numerical results show that the antiferromagnetic intralayer coupling J2 has an important influence on internal energy and specific heat for a four-sublattice system with antiferromagnetic （or ferrimagnetic） interlayer couplings.展开更多
The aim of this paper is to present a rigorous mathematical proof of the dynamical laws for the topological solitons( magnetic vortices) in ferromagnets and anti-ferromagnets. It is achieved through the conservation l...The aim of this paper is to present a rigorous mathematical proof of the dynamical laws for the topological solitons( magnetic vortices) in ferromagnets and anti-ferromagnets. It is achieved through the conservation laws for the topological vorticity and the weak convergence methods.展开更多
This paper presents the methodology and results of modelling of Earth magnetic field disturbances induced by ferromagnetic objects. The modeling was carried out using the finite elements calculations, and the results ...This paper presents the methodology and results of modelling of Earth magnetic field disturbances induced by ferromagnetic objects. The modeling was carried out using the finite elements calculations, and the results were compared with the measurements. The special test stand, consisting of magnetovision scanner and Helmholtz coils, has been used. The measurement system is able to measure the distribution of planar magnetic induction vectors, and to differentiate the sources of measured disturbances.展开更多
This paper is about the automation of the marionette performance. A method to solve the problem on the mobility of the automated marionette performance is proposed. Since it is difficult to control the marionette by h...This paper is about the automation of the marionette performance. A method to solve the problem on the mobility of the automated marionette performance is proposed. Since it is difficult to control the marionette by hands, as an alternative, the automated marionette is studied. However, the automtic marionette performance is limited in the silence and mobility. Therefore, an independent shifter to move freely on the stage is required. The magnetic device which connects the movable robot and the marionette controlling robot is conceived. The magnetic device is improved and applied by considering the features of the marionette robot, which is the irregular movement of the marionette controller and of the parallel limited area. The burden of being trapped on the magnet is minimized by dividing the robot to the upper and lower parts of the marionette performance stage. The direction of the magnet is considered to make the mobile robot to move freely. Thus, the efficiency and safety of the device is confirmed by balancing the strength with the permanent magnet.展开更多
We present our Monte Carlo results of the random-bond Potts ferromagnet with the Olson–Young self-dual distribution of quenched disorders in two dimensions. By exploring the short-time scaling dynamics, we find the u...We present our Monte Carlo results of the random-bond Potts ferromagnet with the Olson–Young self-dual distribution of quenched disorders in two dimensions. By exploring the short-time scaling dynamics, we find the universal power-law critical behavior of the magnetization and Binder cumulant at the critical point, and thus obtain estimates of the dynamic exponent and magnetic exponent , as well as the exponent . Our special attention is paid to the dynamic process for the Potts model.展开更多
Based on the former performance capacity experiments of the magnet-friction energy dissipation devices, including the permanent magnet-friction energy dissipation device (PMF) and electromagnet-friction energy dissipa...Based on the former performance capacity experiments of the magnet-friction energy dissipation devices, including the permanent magnet-friction energy dissipation device (PMF) and electromagnet-friction energy dissipation devices (EMF), a 5-story steel frame model with spacious first story is designed and made according to a scale of 1/4. The magnet-friction energy dissipation devices can realize continuously varied controlling force, with rapid response and reverse recognition. Therefore, they overcome shortcomings usually found in energy dissipation devices whose force models are invariable. The two kinds of devices were fixed on the flexible first story of the structure model, and the shaking table tests have been carried out, respectively. In these tests, the performance of the devices and their effectiveness in structural control were confirmed. In this paper, the test results and analysis are discussed.展开更多
A novel micro-machined diamagnetic stable.levitation system （MDSLS） which is composed of a free permanent magnetic rotor, a ring lifting permanent magnet and two diamagnetic stabilizers was presented. The static and...A novel micro-machined diamagnetic stable.levitation system （MDSLS） which is composed of a free permanent magnetic rotor, a ring lifting permanent magnet and two diamagnetic stabilizers was presented. The static and dynamic stable characters of MDSLS were analyzed. The coupled non-linear differential equations were used to describe six-degree-of-freedom motion of the levitated rotor, and the equivalent surface current and combined dia- magnetic image current method were utilized to model the interaction forces and torques between the lifting perma- nent magnet and rotor permanent magnet and also between the rotor permanent magnet and diamagnetic sub- strates. Because of difficulty to get analytical solution, the numerical calculation based on Runge-Kutta method was used to solve the dynamic model. The vibration frequencies were identified b~ fast Fourier transform （FFT） analysis. According to their resonance characteristics and parameters, the translational and angular dynamic stiff- ness were also calculated. The results show that the levitation of the rotor in MDSLS is stable, and the MDSLS is potential for the application in levitation inertial sensor.展开更多
Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be low...Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be lower. From the above fact, Minato motor was noticed. In this motor, a unidirectional current flows in the electromagnets. In other words, unidirectional windings are used. In this motor, only strong repulsive force is utilized when a permanent magnet of a rotor and an electromagnet of a stator are adjacent. Hence, torque constant becomes higher and the efficiency of the motor is high. However, an effective value of the electromagnetic current increases because a large current flows in a short period. Therefore, copper loss increases and the efficiency of the motor decreases. In order to solve above defects, a new motor is proposed. From the experiment, it is clarified that the efficiency of the proposed motor is higher than that of the commercial motors.展开更多
基金Project(NCET-10-0834)supported by the Program for New Century Excellent Talents in University,China
文摘The solid-state reduction kinetics of pre-oxidized vanadium-titanium magnetite concentrate was studied. The phase and microstructure of the reduction product were characterized by XRD, SEM and EDS methods, based on which the mechanism of the solid-state reduction was investigated. The results showed that using coal as reductant at 950-1100 °C, the solid-state reduction of the pre-oxidized vanadium-titanium magnetite concentrate was controlled by interface chemical reaction and the apparent activation energy was 67.719 k J/mol. The mineral phase transformation during the reduction process can be described as follows： pre-oxidized vanadium-titanium magnetite concentrate → ulvospinel → ilmenite → Fe Ti2O5 →（FenTi1-n）Ti2O5. M3O5-type（M can be Fe, Ti, Mg, Mn, etc） solid solutions would be formed during the reduction process of the pre-oxidized vanadium-titanium magnetite concentrate at 1050 °C for 60 min. The poor reducibility of iron in M3O5 solid solutions is the main reason to limit the reduction property of pre-oxidized vanadium-titanium magnetite concentrate.
文摘In this paper, with the non-salient pole permanent magnet linear synchronous motor (PMLSM)being cited, by using Fourier transform method and "slot-by-slot", "pole -by-pole" current approach, a 3D electromagnetic field model of PMLSM is established. Special attention is paid to its structure and the influence of longitudinal and transverse end effect. The distribution of electromagnetic field of PMLSM can be obtained directly and promptly by using FFT algorithm. It can also be used for the analysis of other LSM.
基金funded by the National Natural Science Foundation of China(No.22173057 for Yongle Li and No.51690164 for Xi Li)the Foundation of Shanghai Science and Technology Commission(No.21JC1402700 and No.21DZ2304900 for Yongle Li)supported by Open Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University。
文摘In this work,the solidification of liquid iron with or without external magnetic field was investigated by using two molecular dynamics methods,namely direct cooling and two-phase simulation.The influence of external magnetic field on the solidification is characterized by the critical temperature and radial distribution functions.Our computational results show that under external magnetic field,the solidification point tends to decrease significantly.By further analyzing the diffusion coefficients and viscosity,we attribute the effect to the stronger fluctuation of liquid iron atoms driven by the external magnetic field.
基金Project supported by the Natural Science Foundation of Liaoning Province （Grant No 20041021）, the Scientific Foundation of the Educational Department of Liaoning Province （Grant No 2004C006） and the Postdoctoral Foundation of Shenyang University of Technology.
文摘The internal energy and specific heat of a Heisenberg ferro- antiferromagnetic double-layer system are studied by using spin-wave theory and the retarded Green function method at low temperatures. Numerical results show that the antiferromagnetic intralayer coupling J2 has an important influence on internal energy and specific heat for a four-sublattice system with antiferromagnetic （or ferrimagnetic） interlayer couplings.
文摘The aim of this paper is to present a rigorous mathematical proof of the dynamical laws for the topological solitons( magnetic vortices) in ferromagnets and anti-ferromagnets. It is achieved through the conservation laws for the topological vorticity and the weak convergence methods.
文摘This paper presents the methodology and results of modelling of Earth magnetic field disturbances induced by ferromagnetic objects. The modeling was carried out using the finite elements calculations, and the results were compared with the measurements. The special test stand, consisting of magnetovision scanner and Helmholtz coils, has been used. The measurement system is able to measure the distribution of planar magnetic induction vectors, and to differentiate the sources of measured disturbances.
基金supported bythe Ministry of Knowledge Economy,Korea,theITRC(Information Technology Research Center)support program(NIPA-2010-(C1090-1021-0010))the Brain Korea 21 Project in 2010
文摘This paper is about the automation of the marionette performance. A method to solve the problem on the mobility of the automated marionette performance is proposed. Since it is difficult to control the marionette by hands, as an alternative, the automated marionette is studied. However, the automtic marionette performance is limited in the silence and mobility. Therefore, an independent shifter to move freely on the stage is required. The magnetic device which connects the movable robot and the marionette controlling robot is conceived. The magnetic device is improved and applied by considering the features of the marionette robot, which is the irregular movement of the marionette controller and of the parallel limited area. The burden of being trapped on the magnet is minimized by dividing the robot to the upper and lower parts of the marionette performance stage. The direction of the magnet is considered to make the mobile robot to move freely. Thus, the efficiency and safety of the device is confirmed by balancing the strength with the permanent magnet.
文摘We present our Monte Carlo results of the random-bond Potts ferromagnet with the Olson–Young self-dual distribution of quenched disorders in two dimensions. By exploring the short-time scaling dynamics, we find the universal power-law critical behavior of the magnetization and Binder cumulant at the critical point, and thus obtain estimates of the dynamic exponent and magnetic exponent , as well as the exponent . Our special attention is paid to the dynamic process for the Potts model.
文摘Based on the former performance capacity experiments of the magnet-friction energy dissipation devices, including the permanent magnet-friction energy dissipation device (PMF) and electromagnet-friction energy dissipation devices (EMF), a 5-story steel frame model with spacious first story is designed and made according to a scale of 1/4. The magnet-friction energy dissipation devices can realize continuously varied controlling force, with rapid response and reverse recognition. Therefore, they overcome shortcomings usually found in energy dissipation devices whose force models are invariable. The two kinds of devices were fixed on the flexible first story of the structure model, and the shaking table tests have been carried out, respectively. In these tests, the performance of the devices and their effectiveness in structural control were confirmed. In this paper, the test results and analysis are discussed.
基金The National Natural Science Foundation ofChina (No60402003)The Weaponry Pre-liminary Research Foundation of China (No9140A09020706JW0314)
文摘A novel micro-machined diamagnetic stable.levitation system （MDSLS） which is composed of a free permanent magnetic rotor, a ring lifting permanent magnet and two diamagnetic stabilizers was presented. The static and dynamic stable characters of MDSLS were analyzed. The coupled non-linear differential equations were used to describe six-degree-of-freedom motion of the levitated rotor, and the equivalent surface current and combined dia- magnetic image current method were utilized to model the interaction forces and torques between the lifting perma- nent magnet and rotor permanent magnet and also between the rotor permanent magnet and diamagnetic sub- strates. Because of difficulty to get analytical solution, the numerical calculation based on Runge-Kutta method was used to solve the dynamic model. The vibration frequencies were identified b~ fast Fourier transform （FFT） analysis. According to their resonance characteristics and parameters, the translational and angular dynamic stiff- ness were also calculated. The results show that the levitation of the rotor in MDSLS is stable, and the MDSLS is potential for the application in levitation inertial sensor.
文摘Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be lower. From the above fact, Minato motor was noticed. In this motor, a unidirectional current flows in the electromagnets. In other words, unidirectional windings are used. In this motor, only strong repulsive force is utilized when a permanent magnet of a rotor and an electromagnet of a stator are adjacent. Hence, torque constant becomes higher and the efficiency of the motor is high. However, an effective value of the electromagnetic current increases because a large current flows in a short period. Therefore, copper loss increases and the efficiency of the motor decreases. In order to solve above defects, a new motor is proposed. From the experiment, it is clarified that the efficiency of the proposed motor is higher than that of the commercial motors.
