Zhang, H. [P:(DE-HGF)0] ; Rolf, Christian [P:(DE-Juel1)139013] ; Tillmann, Ralf [P:(DE-Juel1)5344] ; Wienhold, F. [P:(DE-HGF)0] ; Leisner, T. [P:(DE-HGF)0] ; Saathoff, H. [P:(DE-HGF)0]