N时 JEOL-6490 Scanning Electron Microscopy (SEM) 3nm 30KV 8nm 3KV 15nm 1KV source:cernhttp://microcosm.webcernch/microcosmsource: CERN http://microcosm.web.cern.ch/microcosm JEOL-6490 Scanning Electron Microscopy （SEM） 3nm @ 30KV 8nm @ 3KV 15nm @ 1KV