5,189 research outputs found
A Novel Stator Doubly Fed Doubly Salient Permanent Magnet Brushless Machine
A novel stator doubly fed doubly salient permanent magnet (PM) brushless machine is proposed. The novelty of this machine is to purposely add an extra flux path in shunt with each PM pole, hence amplifying the effect of flux weakening for constant power operation. Magnetic circuit analysis is adopted to illustrate the novelty. Machine flux paths and performance curves determined by a finite-element analysis are presented for various excitations. The corresponding results show that the proposed machine is promising for application to electric vehicles.published_or_final_versio
Entanglement and measurement-induced nonlocality of mixed maximally entangled states in multipartite dynamics
postprin
Transient analysis of a new outer-rotor permanent-magnet brushless DC drive using circuit-field-torque coupled time-stepping finite-element method
In this paper, a new outer-rotor permanent magnet (PM) brushless dc drive is designed and analyzed. To enable this drive applicable to electric vehicles, its transient performances at both normal and flux-weakening operations are particularly focused. The distinct feature in design is due to the new motor configuration including the outer-rotor topology, the multipole magnetic circuit and the full slot-pitch coil span arrangement. The distinct feature in analysis is due to the development of the circuit-field-torque coupled time-stepping finite-element method. The proposed PM brushless dc drive is prototyped. The analysis results are verified by experimental measurement.published_or_final_versio
Design and analysis of a new multiphase polygonal-winding permanent-magnet brushless dc machine
In this paper, a new multiphase polygonal-winding permanent-magnet brushless dc (PMBDC) machine is proposed anal analyzed. The originality of the proposed machine lies on the multiphase polygonal-winding stator anal the surface-inset permanent-magnet rotor. Because of its unique structure and operating principle, a circuit-field-torque coupled time stepping finite-element method is also employed for analysis. The designed machine is prototyped and the analysis is verified by experimentation.published_or_final_versio
Scalar control of a new phase-decoupling permanent magnet synchronous motor for servo application
This paper presents a new scalar-controlled phase-decoupling permanent magnet synchronous motor (PD-PMSM) which takes the advantages of smooth torque, fast response and good controllability for servo applications. Because of the PD nature, the proposed scalar control strategy can simply adjust the phase current amplitude and its angle with respect to the back EMF to achieve direct torque control. Experimental results are given to verify the advantages of the proposed scalar-controlled PD-PMSM. © 2005 IEEE.published_or_final_versio
A novel polyphase multipole square-wave permanent magnet motor drive for electric vehicles
A novel high-power-density permanent magnet (PM) motor drive for electric vehicles (EVs) is proposed. The motor is a polyphase multipole square-wave PM motor, which can be classified as a kind of PM brushless DC motor. The distinct features of the proposed motor as compared to those of the conventional PM brushless DC motor are as follows. First, the multipole magnetic circuit arrangement enables the minimization of the magnetic yoke, resulting in the reduction of motor volume and weight. Second, the coil span is purposely designed to be equal to one slot pitch, thus saving the amount of copper used. Third, by using a fractional number of slots per pole per phase, the arrangement of the numbers of poles and slots is so unique that the magnetic force between the stator and the rotor at any rotating position is uniform, hence eliminating the cogging torque that usually occurs in PM motors. Finally, the motor can be controlled to operate at a constant torque region and a constant power region with field weakening, thus both high starting torque and high cruising speed can be achieved. Therefore, as the proposed motor drive possesses the distinct advantages of high power density, high efficiency, and superior dynamic performance, it is very suitable for EV applications. A prototype of a five-phase 22-pole 5 kW motor drive has been designed for an experimental EV.published_or_final_versio
Studies on Anti-Hepatoma Effect of Gan-Ai-Xiao Decoction
Purpose: To explore the anti-hepatoma effect of Gan-Ai-Xiao Decoction (GAXD), a folk remedy.Methods: High performance liquid chromatography (HPLC) was used to identify the major chemical components of GAXD ethanol extract (EE). The cytotoxic effect of GAXD EE against HepG2 cells was measured by methyl thiazolyl tetrazolium (MTT) assay. Flow cytometry and Western blot were used to study the effect of GAXD EE on apoptosis and apoptotic proteins (Bcl-2, Bax and caspase-3) in HepG2 cells. Xenograft assay was used to evaluate the anti-hepatoma effect of GAXD EE in vivo.Results: Four components were identified in GAXD EE by HPLC. The results of MTT and flow cytometry assays indicated that GAXD EE significantly reduced HepG2 cells viability (p < 0.05) and induced its apoptosis. The results of Western blot assay suggested that GAXD EE down-regulated the expression of anti-apoptotic protein (Bcl-2) and up-regulated the expression of pro-apoptotic proteins (Bax and caspase-3) in HepG2 cells. Furthermore, the results of xenograft assay showed that GAXD EE significantly inhibited the growth of HepG2 cells-induced tumor (p < 0.05) without any effect on the body weight of nude mice.Conclusion: GAXD has anti-hepatoma activity, and the mechanism is associated with apoptosis.Keywords: Gan-Ai-Xiao Decoction, Anti-hepatoma, Flow Cytometry, Western Blot, Xenograft, HepG2 cells, Apoptosi
Isolation and Characterization of Batatasin III and 3,4’- Dihydroxy-5-methoxybibenzyl: A Pair of Positional Isomers from Sunipia scariosa
Purpose: To isolate and characterize chemical compounds of biological importance from the whole plant of Sunipia scariosa.Methods: The whole plant of Sunipia scariosa was extracted with methanol (MeOH) and chromatographed on silica gel and sephadex LH-20 to afford the pure isolates. High perfomance liquild chromatography (HPLC) was used for further purification of the isolated compounds. Characterization ofthe isolated compounds was achieved by 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS).Results: Batatasin III (3,3’-dihydroxy-5-methoxybibenzyl) and 3,4’-dihydroxy-5-methoxybibenzyl, a pair of positional isomers, were isolated from the whole plant of Sunipia scariosa. The yields of the two isomers were 60 and 40 %, respectively, from the mixture of two compounds.Conclusion: Batatasin III and 3,4’-dihydroxy-5-methoxybibenzyl, a pair of positional isomers were successfully isolated from the whole plant of Sunipia scariosa for the first time.Keywords: Sunipia scariosa, Batatasin III, 3,4’-Dihydroxy-5-methoxybibenzyl, Isomer
High-Performance Deep Ultraviolet Photodetector Based on NiO/β-Ga2O3 Heterojunction
Ultraviolet (UV) photodetector has attracted extensive interests due to its wide-ranging applications from defense technology to optical communications. The use of wide bandgap metal oxide semiconductor materials is of great interest in the development of UV photodetector due to their unique electronic and optical properties. In this work, deep UV photodetector based on NiO/β-Ga2O3 heterojunction was developed and investigated. The β-Ga2O3 layer was prepared by magnetron sputtering and exhibited selective orientation along the family of (2¯¯¯ 01) crystal plane after annealing. The photodetector demonstrated good performance with a high responsivity (R) of 27.43 AW−1 under a 245-nm illumination (27 μWcm−2) and the maximum detectivity (D*) of 3.14 × 1012 cmHz1/2 W−1, which was attributed to the p-NiO/n-β-Ga2O3 heterojunction
Panel: Bodily Expressed Emotion Understanding Research: A Multidisciplinary Perspective
Developing computational methods for bodily expressed emotion understanding can benefit from knowledge and approaches of multiple fields, including computer vision, robotics, psychology/psychiatry, graphics, data mining, machine learning, and movement analysis. The panel, consisting of active researchers in some closely-related fields, attempts to open a discussion on the future of this new and exciting research area. This paper documents the opinions expressed by the individual panelists
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