The charge transfer processes for the Be q+ +H (q=1-4) collisions are investigated by the quantum-mechanical and semiclassical methods in wide energy ranges. The total, n-selective, nl-selective, singlet and triplet charge transfer cross sections are obtained and compared with other available theoretical data. The total and n-selective data are presented. The validity of different methods is discussed. The recommend cross section data are given for all collision systems.

Abstract. In this paper, the influence of different cross-section shapes of train body on aerodynamic performance has been investigated by numerical simulations. Computational fluid dynamics (CFD) is used with the second-order finite volume method with SST k-omega turbulence model. The results indicate that the aerodynamic performance is strongly affected by different cross-section shapes of train body, such as cross-sectional area, width-to-height ratio of crosssection, cross-section with straight or curved sides, etc.. Firstly, the drag coefficient and the overturning moment increase as the sides of cross-section become more curved. Secondly, the drag coefficient and the overturning moment are reduced as the width-to-height ratio of the cross-section is increased when the cross-sectional area is kept as a constant. Finally, air pressure pulse produced by two trains passing by in tunnel is approximately proportional to the cross-sectional area in a certain range and is independent to the cross-section shapes. Numerical results can be used for aerodynamic shape design of high speed trains.