Probably not Fagus or Carpinus. Carpinus is too serrated and not enough "heart" shape where the leaf joins to the stem. Fagus is too ruffled along the edge.
Possibly Fagus engleriana. http://www.google.co.uk/imgres?imgu...us+engleriana+leaf&um=1&hl=en&sa=N&tbs=isch:1 http://www.asianflora.com/Fagaceae/Fagus-engleriana.jpg