Table 6 Fitting value of formula coefficient

3R5DC50

5R5DC50

7R5DC50

3R6DC50

5R6DC50

7R6DC50

b

1.95689

1.38823

1.0096

1.77517

1.24431

0.89903

a

1.85343

1.22017

0.8260

1.61997

1.06921

0.71535

b-a

0.10346

0.16806

0.1836

0.1552

0.1751

0.18368

3R7DC50

5R7DC50

7R7DC50

3R8DC50

5R8DC50

7R8DC50

b

1.68823

1.15505

0.8111

1.60598

1.05619

0.67428

a

1.55352

0.99049

0.6294

1.46321

0.88131

0.51468

b-a

0.13471

0.16456

0.1817

0.14277

0.17488

0.1596