Table 1. Experimental Ranges and Levels of the ECH Dosages of the First (X1) and Second Cross-Linking (X3) and Imprinting pH (X2).
range and level |
|||
---|---|---|---|
independent variables | low (−1) | center (0) | high (+1) |
first cross-linking ECH, % (X1) | 0.10 | 0.55 | 1.00 |
imprinting pH (X2) | 1.0 | 1.7 | 2.4 |
second cross-linking ECH, % (X3) | 0.10 | 0.55 | 1.00 |