Modes in EM 成像：中间镜的物平面与物镜的像平面重合 衍射：中间镜的物平面与物镜的背焦面重合 Electron beam 改变中间镜电流 Objective lens Objective aperture (back focal plane) Fixed (diffraction pattern) SAD aperture Intermediate image 1 Voltage (kV) 2(nm) ←Strength→ Intermediate lens 40 0.00601 change 100 0.00370 200 0.00251 Intermediate Intermediate diffraction image 2 300 0.00223 pattern Projector lens X-ray 0.1542 Fixed (Cu-K) strength www.globalsino.com/EM/ Diffraction Final pattern Screen image 4 (a) (b)Modes in EM 4 Voltage (kV)  (nm) 40 0.00601 100 0.00370 200 0.00251 300 0.00223 X-ray 0.1542 (Cu-K ) 成像：中间镜的物平面与物镜的像平面重合 衍射：中间镜的物平面与物镜的背焦面重合 改变中间镜电流