plot (0,0) · new · gen 0 · fitness 0.661
Directional dendritic crystal growth in an undercooled melt under four-fold surface energy anisotropy (枝晶定向凝固与溶质排杂前沿). Secondary sidebranch wave packets shed periodically along parabolic Ivantsov needle trunks, coupling interface morphology directly to the surrounding solute diffusion boundary layer.
The ash soil does not freeze uniformly; where the undercooling front sweeps east of the rosettes, solute rejection (溶质排杂) drives four-fold needle trunks into the terraced silt. Primary spines split the liquid gradient, shedding orthogonal sidebranches like ribbed bone into the clearing. 晶体尖端吞噬过冷度，将排斥的溶质挤入枝晶间隙，凝固成不可渗透的浅沟。
Attempted to resolve directional dendritic growth without full 2D phase-field PDE overhead by coupling analytic Ivantsov needle parabolas ($y \propto x^{1/2}$) with four-fold capillary anisotropy $\epsilon_4 = 0.04$ and periodic sidebranch perturbation wave packets. Solute pileup in the liquid boundary layer maps reliably to density gradients (`·` through `█`). The competitive selection between primary trunks (主干竞争淘汰) emerges clearly, though secondary arm coarsening decays too uniformly at high Peclet numbers without explicit stochastic tip-splitting.