.

Fig. A1.. (a) Schematic diagram shows the definition for the arrangement direction ${{\overset{\scriptscriptstyle\rightharpoonup}{h}}_{i}}$ of a half of excess atomic plane of edge dislocation in 2D plane, and also for the direction of Burgers vector ${{\overset{\scriptscriptstyle\rightharpoonup}{b}}_{i}}$ of the edge dislocation corresponding to the half of the excess atomic arrangement direction ${{\overset{\scriptscriptstyle\rightharpoonup}{h}}_{i}}$: (I) for “up” direction of h_i corresponding Burgers vector b_i; (II) for “down” direction of h_i corresponding Burgers vector b_i; (III) The symbolic meaning of “⊥” of dislocation. (b) Schematic diagram of the six possible composite vector B_i of the dislocation pairs constituted by B_i=b_i+b_i+1, which corresponds to Fig. 4(c).