[1] [1] Zhou L W, Gong H, Zhang Z Q, et al. Paraxial imaging electron optics and its spatial-temporal aberrations for a bi-electrode concentric spherical system with electrostatic focusing［J］. Optik, 2011, 122(4): 295-299.

[2] [2] Zhou L W, Gong H, Zhang Z Q, et al. Static and dynamic imaging electron optics and spatial-temporal aberrations in a bi-electrode spherical concentric system with electrostatic focusing［J］. Optik, 2011, 122(4): 287-294.

[3] [3] Zhou L W. Electron optics with wide beam focusing［M］. Beijing: Beijing Institute of Technology Press, 1993.

[4] [4] Zhou L W. Electron optics of concentric spherical electromagnetic focusing systems［J］. Advances in Electronics and Electron Physics, 1979, 52: 119-132.

[5] [5] Zhou L W, Gong H. Theory of paraxial lateral aberrations of electrostatic imaging electrostatic electron optics based on asymptotic solutions and its verification［J］. Optik, 2011, 122(4): 300-306.

[6] [6] Monastyrski M A. On asymptotic solutions of paraxial equation of electron optics［J］. Journal of Technical Physics, 1978, 48(6): 1117-1122.

[7] [7] Zhou L W. Imaging electron optics of a combined electromagnetic concentric spherical system. Part A: paraxial optics［J］. Acta Optica Sinica, 2019, 39(4): 0411001.

[8] [8] Zhou L W. Imaging electron optics of a combined electromagnetic concentric spherical system. Part B: paraxial aberration［J］. Acta Optica Sinica, 2019, 39(4): 0411002.

[9] [9] Zhou L W. Imaging electron optics of a combined electromagnetic concentric spherical system. Part C: approximate solutions of paraxial equation［J］. Acta Optica Sinica, 2019, 39(4): 0411003.