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Shen Y.,University of Sheffield | Shen Y.,Wuhan Naval University of Engineering | Liu G.Y.,Guangxi Teachers Education University | Xia Z.P.,University of Sheffield | Zhu Z.Q.,University of Sheffield
IEEE Transactions on Industrial Electronics

This paper develops a 2-D field analytical model for predicting the magnetic field distribution and the corresponding electromagnetic performance in air- and iron-cored permanent magnet (PM) brushless machines having radially or parallel magnetized two-segment Halbach array. A simple equation is derived to directly predict the optimal magnet ratio for maximum electromagnetic torque, while the influence of pole-pair number and magnet thickness on the optimal magnet ratio is investigated for both air- and iron-cored machines. The analytical model is validated by finite-element analyses and also measurements on a prototype 12-slot/10-pole PM brushless machine. © 1982-2012 IEEE. Source

Guan N.-N.,Guangxi Teachers Education University
Wuli Xuebao/Acta Physica Sinica

Dileptons have large mean free paths due to their small cross sections for electromagnetic interaction in plasma. Therefore they are considered to be an important probe for the formation and evolution of the quark matter. In this work, we calculate the dilepton production of quark-gluon plasma (QGP) produced in Au197+ Au197 central collisions at relativistic heavy ion collider (RHIC) energy based on the evolution model of a chemically equilibrating viscous QGP. The evolution of the QGP system is described by a set of coupled relaxation equations containing the master equations of partons, the equation of baryon number conservation and equation of energy-momentum conservation. Solving the set of evolution equations, one can obtain the evolution of temperature T, quark chemical potential μq, fugacities λq for quarks and λg for gluons. To discuss the shear viscosity of QGP, the contributions of the elastic scattering of quarks qq→qqand gluons gg→gg, as well as the inelastic scattering process of gluons gg↔ggg are included. Based on the evolution model including the viscosity, we perform a complete calculation of the dilepton production, including the processes of quark-antiquark annihilation qq→ll, next-order annihilation qq→gll, Compton-like scattering qg →qll, qg → qll, multiple scattering of quarks, as well as gluon fusion gg →cc, annihilation qq→cc. It is found that the spectra from the quark-antiquark annihilations qq→ll and qq→gll are dominated. The contributions from multiple scattering cannot be neglected. We also find that the dilepton yields remarkably decrease with considering an additional gluon inelastic process in the calculation compared with the results with considering only elastic scatterings of quarks and gluons. This indicates that the evolution of QGP system is accelerated and the evolution time is shortened by the inelastic scatterings of gluons. © 2016 Chinese Physical Society. Source

Cao J.,South China University of Technology | Yang Q.,South China University of Technology | Huang Z.,Guangxi Teachers Education University
Nonlinear Analysis: Real World Applications

In this paper, a class of stochastic functional differential equations given by dx(t)=(Ax(t)+F(t,x(t), xt))dt+G(t,x(t), xt) °dω(t),t∈[0,T],x(t)=φ(t)fort∈[-σ,0], is investigated. Under some suitable assumptions, the existence and stability of quadratic-mean almost periodic mild solutions for the equations are discussed by means of semigroups of operators and fixed point method. Moreover, an example is given to illustrate our results. © 2011 Elsevier Ltd. All rights reserved. Source

Yang J.,Guangxi Teachers Education University
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji

A cave-dwelling loach, Oreonectes luochengensis sp. nov. has been described based on collections from a cave in Tianhe town, Luocheng, Guangxi, China in September 2008. It can be distinguished from all known Oreonectes species by the following combination of characters: dorsal-fin rays 3, 7; anal-fin rays 2, 5; pectoral-fin rays 1, 11-12; pelvic-fin rays 1, 7 and 14-16 branched caudal-fin rays; head compressed; eyes present; surface of lower lip covered with shallow longitudinal groove; dorsal-fin origin posterior to vertical line of pelvic-fin origin; caudal peduncle without caudal-adipose keels; edge of caudal fin truncation; tiny scales present under skin; no cephalic lateral-line system; body pink in living status, without pigments in adult, after fixed in formalin, body yellowish, non-transparent, no markings on body side. Source

Yang J.,Guangxi Teachers Education University
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji

A new blind loach of the genus Triplophysa was collected in 2007 from a cave in Leyi village, located near Chuanshan Town, Huangjiang County in the Guangxi Zhuang Autonomous Region of southern China. The new species, Triplophysa huangjiangensis sp. nov, can be distinguished from its congeners by eyes and scales absent; caudal-fin forked; adipose keel present; lips with furrows; distal margin of dorsal-fin truncate, dorsal fin origin much closer to caudal-fin base than snout tip; 8-9 branched dorsal-fin rays; 6-7 branched pelvic-fin rays; 6 branched anal-fin rays; 10-11 branched pectoral-fin rays; 13-14 branched caudal-fin rays; pectoral-fin length 52.3%-70.7% the distance between pectoral-fin origin to pelvic-fin origin; dorsal-fin origin posterior to vertical line of pelvic-fin origin; outer rostral barbel longer than other two pairs of barbels, with 47.0%-73.8% of lateral head length; anterior nostril with elongate barbel-like tip; and posterior chamber of gas-bladder developed, reaching pelvic-fin origin. Source

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