Research on the Drawing-up of the Pole Figure for Orientation Analysis of Directional Si Steel Sheet

The magnetic property of soft magnetic metals and alloys depends strongly on the crystallo-graphic orientation. In automated equipment for orientation research, the intensity for drawing up the pole figure is measured in detail. The present research shows that the accurate pole figure can be drawn up without measuring concretely the intensity. For directional Si steel sheet the measuring step may be 4～5 degrees. In this paper the experimental equation for defo-cusing correction was derived from the experimental data in different specimens with random orientation.

Rotor orientation direction controls geometric curvature and chirality for assemblies of motor amphiphiles in water

Control over geometric curvature and chirality of assemblies in pure aqueous media is key to the design of responsive materials and molecular machines.Here we show how aggregate geometric curvature and chirality of motor amphiphiles could be switched from bicontinuous calabashes to nanoribbons or from vesicles to nanoribbons by modulating rotor orientation direction with dual light/heat stimuli to influence spontaneous curvature in assemblies.The photoisomerization and thermal helix inversion processes of molecular motors have been studied at the molecular level,and the transformation of supramolecular assemblies has been investigated at the microscopic level.The morphological evolution of the calabash-shaped assembly can be kinetically captured,suggesting that the bicontinuous calabash-shaped structures are different from the bowl-shaped aggregates based on solvent-driven assembly upon the addition of non-solvent or solvent.The investigation of dual optical/thermal control of rotor orientation can provide a new strategy for tuning the geometric curvature and chirality of nanoassemblies at the nanoscale,arriving ultimately the clusteroluminescence through-space electronic communication at responsive supramolecular nanosystems.

Direct field oriented control scheme for space vector modulated AC/DC/AC converter fed induction motor

This paper investigates a Luenberger flux observer with speed adaptation for a direct field oriented control of an induction motor. An improved method of speed estimation that operates on the principle of speed adaptive flux and current observer has been proposed. An observer is basically an estimator that uses a plant model and a feedback loop with measured stator voltage and current. Simulation results show that the proposed direct field oriented control with the proposed observer provides good performance dynamic characteristics. The induction motor is fed by an indirect power electronics converter. This indirect converter is controlled by a sliding mode technique that enables minimization of harmonics introduced by the line converter, as well as the control of the power factor and DC-link voltage. The robustness of the overall system is studied using simulation for different operating modes and varied parameters.

Effect of Sedimentation on the Microwave Permeability of FeSiAl Composites

In order to achieve an easy fabrication and considerable directional orientation, we use a sedimentation method to prepare composites consisting of Fe Si Al flakes. The flakes are dispersed in hydroxylated acrylic resin solution in sonication and natural form into laminated composite samples. Then, the toroidal rings are made with the prepared laminated composite samples. Compared with random orientational Fe Si Al flakes in the composite, the complex permeability of laminated sample has been obviously improved when microwave frequency is below 4 GHz, especially for the imaginary part. A model is proposed to explain the formation reason of aligned Fe Si Al composite by this method. Damping factor（α） is calculated by the combination of the effective medium theory and Landau-Lifshitz-Gilbert equation, and the permeability of the samples is verified by these theories.