兰州重离子加速器放射性次级束分离线一号线(Heavy Ion Research Facility in Lanzhou-Radioactive Ion Beam Line 1,HIRFL-RIBLL1)已运行多年,其电源控制系统因建设初期条件所限设计较为简单,加之近年来系统部件老化,已不能很好满足物...兰州重离子加速器放射性次级束分离线一号线(Heavy Ion Research Facility in Lanzhou-Radioactive Ion Beam Line 1,HIRFL-RIBLL1)已运行多年,其电源控制系统因建设初期条件所限设计较为简单,加之近年来系统部件老化,已不能很好满足物理实验要求,迫切需要进行升级改造。新的电源控制系统针对现有问题,采用分布式架构,每台电源用一台高精度控制器就近控制。同时集成了二极磁铁磁场强度和所有电源输出电流的监控,并且利用滞环控制策略,实现了根据预设磁刚度自动调试电源的功能。新电源控制系统经过一年多来的几次实验调束验证,在调试精度、抗干扰性、易用性等方面满足了RIBLL1物理需求,大幅度提高了调束效率。展开更多
To address the problem of subdividing inflexible rectangular grid models and their poor definition of velocity interfaces,we propose a complex structure triangular net for a minimum traveltime ray tracing global algor...To address the problem of subdividing inflexible rectangular grid models and their poor definition of velocity interfaces,we propose a complex structure triangular net for a minimum traveltime ray tracing global algorithm.Our procedure is：（1） Subdivide a triangle grid based on the Delaunay triangular subdivision criterion and the relationships of the points,lines,and the surfaces in the subdividing area.（2） Define the topology relationships and related concepts of triangular unit ray tracing.（3） The source point and wave arrival points at any time compose the propagating plane wave and the minimum traveltime and secondary source positions are calculated during the plane wave propagation.We adopt the hyperbolic approximation global algorithm for secondary source retrieving.（4） By minimum traveltime ray tracing,collect the path from receiver to source points with the neighborhood point＇s traveltime and the direction of the secondary source.Numerical simulation examples are given to test the algorithm.The results show that the triangular net ray tracing method demonstrates model subdivision flexibility,precise velocity discontinuity interfaces,and accurate computations.展开更多
We theoretically investigate the evolvement of dark spatial soliton withcascading quadratic nonlinearity in quasi-phase-matched second harmonic generation. It is shown thatthe dark solitary wave can propagate stably w...We theoretically investigate the evolvement of dark spatial soliton withcascading quadratic nonlinearity in quasi-phase-matched second harmonic generation. It is shown thatthe dark solitary wave can propagate stably when background intensity is large enough, in whichdiffraction of beam can be balanced by the cascading quadratic nonlinearity. We also analyze theinfluence of phase-mismatch on the stabihty of dark soliton propagation.展开更多
In this paper, the famous Amann three-solution theorem is generalized. Multiplicity question of fixed points for nonlinear operators via two coupled parallel sub-super solutions is studied. Under suitable conditions, ...In this paper, the famous Amann three-solution theorem is generalized. Multiplicity question of fixed points for nonlinear operators via two coupled parallel sub-super solutions is studied. Under suitable conditions, the existence of at least six distinct fixed points of nonlinear operators is proved. The theoretical results are then applied to nonlinear system of Hammerstein integral equations.展开更多
文摘兰州重离子加速器放射性次级束分离线一号线(Heavy Ion Research Facility in Lanzhou-Radioactive Ion Beam Line 1,HIRFL-RIBLL1)已运行多年,其电源控制系统因建设初期条件所限设计较为简单,加之近年来系统部件老化,已不能很好满足物理实验要求,迫切需要进行升级改造。新的电源控制系统针对现有问题,采用分布式架构,每台电源用一台高精度控制器就近控制。同时集成了二极磁铁磁场强度和所有电源输出电流的监控,并且利用滞环控制策略,实现了根据预设磁刚度自动调试电源的功能。新电源控制系统经过一年多来的几次实验调束验证,在调试精度、抗干扰性、易用性等方面满足了RIBLL1物理需求,大幅度提高了调束效率。
基金the National Natural Science Foundation of China(Grant Nos.50974081,50774051, 51034003)the Foundation for the Author of National Excellent Doctoral Dissertation of PR China(Grant No.200958)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT0843)the Open Research Fund Program of the State Key Laboratory of Coal Resources and Safe Mining(China University of Mining and Technology, Beijing)(No.2007-07)
文摘To address the problem of subdividing inflexible rectangular grid models and their poor definition of velocity interfaces,we propose a complex structure triangular net for a minimum traveltime ray tracing global algorithm.Our procedure is：（1） Subdivide a triangle grid based on the Delaunay triangular subdivision criterion and the relationships of the points,lines,and the surfaces in the subdividing area.（2） Define the topology relationships and related concepts of triangular unit ray tracing.（3） The source point and wave arrival points at any time compose the propagating plane wave and the minimum traveltime and secondary source positions are calculated during the plane wave propagation.We adopt the hyperbolic approximation global algorithm for secondary source retrieving.（4） By minimum traveltime ray tracing,collect the path from receiver to source points with the neighborhood point＇s traveltime and the direction of the secondary source.Numerical simulation examples are given to test the algorithm.The results show that the triangular net ray tracing method demonstrates model subdivision flexibility,precise velocity discontinuity interfaces,and accurate computations.
文摘We theoretically investigate the evolvement of dark spatial soliton withcascading quadratic nonlinearity in quasi-phase-matched second harmonic generation. It is shown thatthe dark solitary wave can propagate stably when background intensity is large enough, in whichdiffraction of beam can be balanced by the cascading quadratic nonlinearity. We also analyze theinfluence of phase-mismatch on the stabihty of dark soliton propagation.
基金This research is supported by NSFC (10071042)NSFSP (Z2000A02).
文摘In this paper, the famous Amann three-solution theorem is generalized. Multiplicity question of fixed points for nonlinear operators via two coupled parallel sub-super solutions is studied. Under suitable conditions, the existence of at least six distinct fixed points of nonlinear operators is proved. The theoretical results are then applied to nonlinear system of Hammerstein integral equations.
