This paper presents most properties of radiation from a tapered Apple-II undulator. The study demonstrates that tapering an Apple-II undulator can broaden the harmonic bandwidth and the performance of polarization is ...This paper presents most properties of radiation from a tapered Apple-II undulator. The study demonstrates that tapering an Apple-II undulator can broaden the harmonic bandwidth and the performance of polarization is also excellent at the broadened energy range. So Apple-II undulator can be tapered to provide more convenience for energy scan experiment.展开更多
Moving IBM （immersed boundary method） is applied to analyze the relative motion of railway car flow in the single-bore subway tunnel with vertical ventilation. The tested car body is modeled by cylinder type body. T...Moving IBM （immersed boundary method） is applied to analyze the relative motion of railway car flow in the single-bore subway tunnel with vertical ventilation. The tested car body is modeled by cylinder type body. The subway tunnel is assumed to be the single-car-passing straight type （single-bore tunnel）. The modeled car is relatively moved forward. On the other hand, the tunnel and vertical ventilation are fixed. The momentum equations are solved by LES （large eddy simulation） method. The initial condition of fluid in the subway tunnel is stationary. The Reynolds number is 1,500 based on the cylinder radius. The turbulent flow field in the subway tunnel and vertical ventilation shaft are to be qualitatively investigated.展开更多
基金Supported by Shanghai Natural Science Foundation (Grant No. 08JC1422500)
文摘This paper presents most properties of radiation from a tapered Apple-II undulator. The study demonstrates that tapering an Apple-II undulator can broaden the harmonic bandwidth and the performance of polarization is also excellent at the broadened energy range. So Apple-II undulator can be tapered to provide more convenience for energy scan experiment.
文摘Moving IBM （immersed boundary method） is applied to analyze the relative motion of railway car flow in the single-bore subway tunnel with vertical ventilation. The tested car body is modeled by cylinder type body. The subway tunnel is assumed to be the single-car-passing straight type （single-bore tunnel）. The modeled car is relatively moved forward. On the other hand, the tunnel and vertical ventilation are fixed. The momentum equations are solved by LES （large eddy simulation） method. The initial condition of fluid in the subway tunnel is stationary. The Reynolds number is 1,500 based on the cylinder radius. The turbulent flow field in the subway tunnel and vertical ventilation shaft are to be qualitatively investigated.
