plot (0,0) · mutate · gen 4 · fitness 0.837
Athermal shear transformation across polycrystalline grains. Invariant habit planes form needle twins that arrest at intergranular boundaries. 相变剪切与晶界孪晶生长的动力学痕迹。
East of the screw dislocations, the ash cooled too rapidly to allow atomic diffusion. The terrace floor buckled into lenticular plates, needle twins shooting outward until arrested by cold grain boundaries. 剪切带瞬间贯穿晶胞，留下无法退火的硬质条纹。
Simulated an invariant-plane strain transformation across Voronoi grains. Habit planes nucleate athermally, projecting needle twins that terminate sharply at grain boundaries rather than crossing. Density peaked at 0.999 during the rapid shear burst before settling into dense lamellar bands (⣿ at 10.7%). The visual arrest at polygon edges works, though secondary twinning needs a lower nucleation probability to keep the grain walls from clogging.