介绍虚拟正交源(virtual quadrature source,VQS)概念,提出一种新颖的相位和幅值可控电压调节器(voltage regulator with controllable phase and amplitude,VRCPA)。其中单相VRCPA由Buck交流斩波器、三次谐波陷阱和Boost交流斩波器组成...介绍虚拟正交源(virtual quadrature source,VQS)概念,提出一种新颖的相位和幅值可控电压调节器(voltage regulator with controllable phase and amplitude,VRCPA)。其中单相VRCPA由Buck交流斩波器、三次谐波陷阱和Boost交流斩波器组成,相对于输入电压,其输出电压的相位和幅值均可分别连续调节。前级Buck交流斩波器和三次谐波陷阱用于调节输出电压的相位,后级Boost交流斩波器用于调节输出电压的幅值。在单相VRCPA基础上构成三相VRCPA,三相VRCPA无需三次谐波陷阱,电路结构简洁。VRCPA可被用于控制电网中的电能传输,具有潜在的应用价值,该文详细研究其电路工作原理。展开更多
We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of...We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensate8 （BECs） by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments.展开更多
Both the homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions of the two-dimensional and time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used ...Both the homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions of the two-dimensional and time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used in describing the system of Bose-Einstein condensates trapped in a harmonic potential. The approximate analytical solutions are obtained successfully. Comparisons between the analytical solutions and the numerical solutions have been made. The results indicate that they are agreement very well with each other when the atomic interaction is not too strong.展开更多
We consider the ground-state properties of a rotating spin-orbit-coupled Bose–Einstein condensate under extreme elongation in a harmonic plus quartic potential. The effects of spin-orbit coupling and rotation on the ...We consider the ground-state properties of a rotating spin-orbit-coupled Bose–Einstein condensate under extreme elongation in a harmonic plus quartic potential. The effects of spin-orbit coupling and rotation on the groundstate vortex structures are investigated. In the absence of spin-orbit coupling, new nucleated vortices gradually form vortex lines and annular vortex structures with the increase of the rotation frequency. In the presence of spin-orbit coupling, part of the vortices arrange in a line and form a stable vortex chain, and the remanent vortices coexist in pairs aside such vortex chain. More specially, the remanent vortices of each component repel each other and form vortex pair for isotropic spin-orbit coupling, while attract each other and locate in the same positions for anisotropic spin-orbit coupling.展开更多
文摘介绍虚拟正交源(virtual quadrature source,VQS)概念,提出一种新颖的相位和幅值可控电压调节器(voltage regulator with controllable phase and amplitude,VRCPA)。其中单相VRCPA由Buck交流斩波器、三次谐波陷阱和Boost交流斩波器组成,相对于输入电压,其输出电压的相位和幅值均可分别连续调节。前级Buck交流斩波器和三次谐波陷阱用于调节输出电压的相位,后级Boost交流斩波器用于调节输出电压的幅值。在单相VRCPA基础上构成三相VRCPA,三相VRCPA无需三次谐波陷阱,电路结构简洁。VRCPA可被用于控制电网中的电能传输,具有潜在的应用价值,该文详细研究其电路工作原理。
基金Supported by NSFC under Grant Nos. 11041003, 10735030, 10874235, 10934010, 60978019, the NKBRSFC under Grant Nos. 2009CB930701, 2010CB922904, and 2011CB921500Zhejiang Provincial NSF under Grant No. Y6090592+1 种基金Ningbo Natural Science Foundation under Grant Nos. 2010A610095, 2010A610103, and 2009B21003K.C. Wong Magna Fund in Ningbo University
文摘We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensate8 （BECs） by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments.
基金Supported by the National Natural Science Foundation under Grant No. 11047010
文摘Both the homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions of the two-dimensional and time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used in describing the system of Bose-Einstein condensates trapped in a harmonic potential. The approximate analytical solutions are obtained successfully. Comparisons between the analytical solutions and the numerical solutions have been made. The results indicate that they are agreement very well with each other when the atomic interaction is not too strong.
基金Supported by the National Natural Science Fund for National Major Scientific Research Equipment and Equipment Special Fund under Grant No.61025023the NMFSEID under Grant No.61127901+2 种基金the Key Project Fund of the CAS“Light of West China”Program under Grant No.2012ZD02the Youth Innovation Promotion Association of CAS under Grant No.2015334the Sichuan Province Education Department key Natural Science Fund under Grant Nos.13ZA0149 and 16ZA0355
文摘We consider the ground-state properties of a rotating spin-orbit-coupled Bose–Einstein condensate under extreme elongation in a harmonic plus quartic potential. The effects of spin-orbit coupling and rotation on the groundstate vortex structures are investigated. In the absence of spin-orbit coupling, new nucleated vortices gradually form vortex lines and annular vortex structures with the increase of the rotation frequency. In the presence of spin-orbit coupling, part of the vortices arrange in a line and form a stable vortex chain, and the remanent vortices coexist in pairs aside such vortex chain. More specially, the remanent vortices of each component repel each other and form vortex pair for isotropic spin-orbit coupling, while attract each other and locate in the same positions for anisotropic spin-orbit coupling.
