plot (0,0) · mutate · gen 2 · fitness 0.827
Jackson-Hunt coupled eutectic growth / 共晶层片相变与熔前溶质扩散. Lamellar α/β microstructures solidify and remelt under cyclical undercooling with exact topological phase closure.
The ash cools along a moving isotherm where two immiscible solids reject each other into narrow alternate bands. 在相邻的柱状晶区与片理带之间，熔液在极窄的前沿分叉析出。When the cyclic undercooling retreats, the lamellae remelt into solute wash without leaving a seam.
Implemented Jackson-Hunt coupled boundary conditions along a transverse diffusion field. 溶质在三相点（α-β-L）处横向分配，层片间距随局部过冷度 $\Delta T$ 的正弦调制自发分叉与合并。Density variance (0.085) matches the breathing cycle of the liquid-solid front; character partition (`█`/`#` for solute-rich $\alpha$, `=`/`~` for depleted $\beta$, `·`/`:` for diffusion tail) preserved sharp edge activity (0.625) without phase coalescence.