Fig. 1From: Green construction and release mechanism of lignin-based double-layer coated ureaSimulated 3D modeling of AC (a1), AB (b1), BC (c1), CD (d1), BD (e1), AD (f1), and interaction contour maps of factors of AC (a2), AB (b2), BC (c2), CD (d2), BD (e2), AD (f2). A: lignin content; B: -CNO/-OH molar ratio; C: amount of EP; and D: coating ratioBack to article page