Isolation and characterization of putative functional long terminal repeat retrotransposons in the Pyrus genome

Annotation of 440 isolated LTR retrotransposons. (XLSX 88 kb

Analysis and Experiment of Eddy Current Loss in Radial Magnetic Bearings with Solid Rotor

In order to reduce power losses for the aerospace applications, this paper analyzes the eddy current losses produced by high-speed rotating solid rotor core magnetic bearings of magnetically suspended control & sensitive gyroscope (MSCSG). An analytical model of the eddy current loss of a solid rotor radial magnetic bearing (RMB) is presented. Considering the difference between NNNN and NSNS magnetic circuits of RMB, the magnetic field expressions of stator magnetic poles are listed. The magnetic field of stator poles is replaced by Fourier series expansion. According to the magnetic field distribution around the magnetic pole surface and the boundary conditions of the rotor surface, the mathematical expression of eddy current loss is obtained. The measurement method of rotational power loss in radial magnetic bearing is proposed, and the results of the theoretical analysis are verified by experiments in the prototype MSCSG. The experimental results show the correctness of calculation results. Eddy current loss models and test methods provide theoretical support for analyzing eddy current losses in solid rotors and reducing power consumption

Analysis and Experiment of Eddy Current Loss in Radial Magnetic Bearings with Solid Rotor

In order to reduce power losses for the aerospace applications, this paper analyzes the eddy current losses produced by high-speed rotating solid rotor core magnetic bearings of magnetically suspended control & sensitive gyroscope (MSCSG). An analytical model of the eddy current loss of a solid rotor radial magnetic bearing (RMB) is presented. Considering the difference between NNNN and NSNS magnetic circuits of RMB, the magnetic field expressions of stator magnetic poles are listed. The magnetic field of stator poles is replaced by Fourier series expansion. According to the magnetic field distribution around the magnetic pole surface and the boundary conditions of the rotor surface, the mathematical expression of eddy current loss is obtained. The measurement method of rotational power loss in radial magnetic bearing is proposed, and the results of the theoretical analysis are verified by experiments in the prototype MSCSG. The experimental results show the correctness of calculation results. Eddy current loss models and test methods provide theoretical support for analyzing eddy current losses in solid rotors and reducing power consumption

Rotation Modes Stability Analysis and Phase Compensation for Magnetically Suspended Flywheel Systems with Cross Feedback Controller and Time Delay

This paper analyzes the effects of time delay on the stability of the rotation modes for the magnetically suspended flywheel (MSFW) with strong gyroscopic effects. A multi-input multioutput system is converted into a single-input single-output control system with complex coefficient by variable reconstruction, and the stability equivalence of the systems before and after variable reconstruction is proven. For the rotation modes, the stability limits and corresponding vibration frequencies are found as a function of nondimensional magnetic stiffness and damping and nondimensional parameters of rotor speed and time delay. Additionally, the relationship between cross feedback control system stability and time delay is investigated. And an effective phase compensation method based on cross-channel is further presented. Simulation and experimental results are presented to demonstrate the correctness of the stability analysis method and the superiority of the phase compensation strategy

A Weighted Evidence Combination Method Based on Improved Conflict Measure Factor

D-S evidence theory is usually used for the fusion of multi-source information. But the fusion result is always against with general knowledge for the heavy conflict of evidence. Research on combination of conflict evidence at home and abroad is summarized and analyzed in detail. On the base of this, the conclusion that modified evidence combination method of conflict evidence is more useful can be dawn. Effective evidence conflict measure is the first step of conflict evidence combination. The existing conflict measure methods are summarized and the main problem of those methods is analyzed in detail. Based on previous research of conflict evidence combination, a modified measure factor of evidence conflict which is called Mconf is put forward. Mconf is mainly built up with modified distance of evidence named mdBPA and traditional evidence conflict factor named k. The examples in this paper show that Mconf can measure the evidence conflict correctly, both for general evidence and conflict evidence. DOI: http://dx.doi.org/10.11591/telkomnika.v14i3.785

Application of Spherical Magnetic Bearing in Magnetically Suspended Control and Sensitive Gyro

This paper presents a spherical magnetic bearing and analyzes its application in magnetically suspended control and sensitive gyro (MSCSG). The main advantage of the spherical magnetic bearing is that it can eliminate the interference torque in the process of rotor tilt and improve the suspension accuracy of the rotor. By comparing the finite element analysis results of spherical magnetic bearing and traditional cylindrical magnetic bearing, the interference torque to the rotor of cylindrical magnetic bearing increases gradually with the increase of the rotor tilt angle. The interference torque to the rotor of spherical magnetic bearing does not change with the rotor tilt, and the interference torque is basically 0 Nm. Then, dynamic and static experiments were carried out to verify the interference torque generated in the process of spherical magnetic suspended rotor tilting. The experimental results show that the runout value of the rotor’s translation and tilt signals in both static and dynamic states is basically consistent with the value of the equilibrium state of the rotor (tilt angle = 0). Therefore, spherical magnetic bearing will not produce interference torque, which is of great significance for realizing the high-precision control of magnetic suspension inertia mechanism

Review on Active Vibration Control Method of Magnetically Suspended System

Recently, magnetic bearings have been widely used in inertial actuators of spacecraft. Aiming at the problem of unbalanced vibration in magnetically suspended system, the research status of active vibration control method is described in detail. Firstly, the structure and working principle of magnetically suspended system are introduced, and the causes of unbalanced vibration are expounded. Then, the research status of active vibration control methods at home and abroad is introduced from two aspects of synchronous vibration and harmonic vibration, and the advantages and disadvantages of each control method are summarized. Finally, the future development trend of active vibration control technology for magnetically suspended system is prospected