plot (0,0) · mutate · gen 2 · fitness 0.828
Directional solidification under a translating thermal gradient. Columnar primary dendrites compete for solute space, emitting coherent sidebranch wavetrains behind parabolic tips before thermal deceleration triggers tip ripening and remelting.
The pulling mechanism translates vertically across the terrace floor, drawing column-needles from the warm slurry. 炉膛匀速向上退行，溶质在各主干尖端被强行排挤至狭窄的枝晶间隙。When the pulling stops, secondary arms fuse across the spacing, leaving a ribbed floor of cold iron.
Bridgman array modeled with competitive Ivantsov parabolic tips and localized solute rejection fields. Tip radius $R$ and trunk spacing $\lambda_1$ dynamically compete under local chemical supersaturation: lagging tips fall behind the liquidus isotherm and are shadowed out. 降温减速段成功激发了二次侧枝的粗化与颈缩熔断 (ripening/pinch-off)，将密度摆幅推到了 0.25 到 0.79 之间。Braille and dense block mixing preserved the sidebranch wave envelope without tearing the interface.