Table 1 Microstructural parameters and main chemical composition changes of corn stover from different pretreatments

182.8 ± 8.2^j

43.8 ± 3.0^ef

40.5 ± 0.3^ab

22.1 ± 0.1^bcd

19.4 ± 0.4^d

46.5 ± 0.1^d

15.9 ± 0.2^a

2.1 ± 0.0^a

1.1 ± 0.0^a

7.8 ± 0.0^a

91.1

226.6 ± 10.9^k

42.9 ± 1.1^e

42.4 ± 0.1^bcd

23.0 ± 0.2^de

17.8 ± 0.4^cd

49.6 ± 0.2^g

19.6 ± 0.1b^a

3.4 ± 0.0^b

25.4 ± 0.2^e

11.9 ± 0.0^e

80.0

250.2 ± 13.1 ^l

47.1 ± 0.2^f

44.2 ± 0.3^edf

23.2 ± 0.2^de

16.7 ± 0.6^c

51.8 ± 0.0^h

25.1 ± 0.1^de

5.8 ± 0.0^h

33.3 ± 0.0^j

15.9 ± 0.0ⁱ

73.6

283.8 ± 7.6^m

43.6 ± 1.8^ef

45.5 ± 1.2^fgh

22.9 ± 0.6^de

14.4 ± 0.6^a

54.7 ± 0.2^j

36.2 ± 0.3^f

8.1 ± 0.1ⁱ

34.1 ± 0.0 ^l

17.2 ± 0.0^j

74.5

81.5 ± 1.2 ^fg

41.5 ± 0.7^de

39.5 ± 1.3^a

21.4 ± 0.6^abc

18.1 ± 0.7 ^cd

46.7 ± 0.1^ef

21.9 ± 0.1^Bb

3.4 ± 0.0^b

1.7 ± 0.0^b

9.3 ± 0.0^c

93.2

86.5 ± 0.7^gh

40.5 ± 0.9^cde

42.7 ± 0.2^abcd

23.5 ± 0.2^ef

16.5 ± 0.9^bc

41.9 ± 0.1^c

20.5 ± 0.0^b

4.8 ± 0.0^f

29.6 ± 0.2^g

15.3 ± 0.0^h

79.3

94.0 ± 0.8^hi

41.2 ± 0.4^de

46.6 ± 0.8^ghi

22.4 ± 0.6^cde

14.8 ± 0.1^ab

47.0 ± 0.0^f

52.4 ± 0.1 ^g

16.7 ± 0.0^j

31.4 ± 0.0ⁱ

24.5 ± 0.0 ^m

72.4

96.1 ± 0.6ⁱ

42.7 ± 1.4^e

48.1 ± 0.2^ijk

21.1 ± 0.2^ab

14.3 ± 0.1^a

60.2 ± 0.1 ^m

98.8 ± 0.1ⁱ

24.1 ± 0.0 ^l

35.7 ± 0.0 ^m

26.0 ± 0.0^o

65.4

37.3 ± 0.2^b

36.6 ± 0.6^ab

39.9 ± 1.2^a

22.2 ± 0.7^bcd

17.0 ± 0.4^c

56.5 ± 0.2 ^k

24.2 ± 0.2^d

3.7 ± 0.0^c

2.2 ± 0.1^c

9.1 ± 0.0^b

92.0

50.3 ± 0.2^c

38.4 ± 1.0^bcd

44.7 ± 0^efg

24.4 ± 0.4^f

17.4 ± 0.4^c

46.2 ± 0.0^d

22.6 ± 0.1^Ad

5.0 ± 0.0^g

28.1 ± 0.1^f

15.0 ± 0.0^g

80.8

65.3 ± 0.3^de

37.4 ± 1.5^abc

47.7 ± 0.9^hij

23.0 ± 0.2^de

14.8 ± 0.5^ab

49.8 ± 0.1^g

56.0 ± 0.0^h

17.7 ± 0.0^k

31.0 ± 0.1^h

25.5 ± 0.0ⁿ

67.5

77.2 ± 0.3^f

35.2 ± 0.7^ab

50.1 ± 0.2^kl

21.0 ± 0.1^ab

14.5 ± 0.3^a

58.5 ± 0.0^l

102.2 ± 0.3^j

24.1 ± 0.0^l

33.7 ± 0.2^k

22.6 ± 0.0 ^l

63.2

27.1 ± 0.2^a

33.6 ± 0.4^a

41.6 ± 0.9^abc

22.9 ± 0.3^de

17.7 ± 1.0^c

40.4 ± 0.1^b

25.6 ± 0.2^e

3.9 ± 0.0^d

1.3 ± 0.0^a

11.7 ± 0.0^d

91.3

37.7 ± 0.1^b

36.1 ± 1.1^ab

43.2 ± 0.6^cde

23.6 ± 0.4^ef

16.5 ± 0.9^bc

37.6 ± 0.2^a

19.8 ± 0.0^b

4.5 ± 0.0^e

23.6 ± 0.2^d

13.2 ± 0.0^f

83.2

56.8 ± 0.1^cd

34.0 ± 0.1^a

49.6 ± 0.7^jkl

23.5 ± 0.4^ef

14.4 ± 0.3^a

54.0 ± 0.0ⁱ

56.1 ± 0.3^h

17.7 ± 0.1^k

34.3 ± 0.1^l

20.2 ± 0.0^k

62.0

67.4 ± 0.4^e

35.4 ± 0.5^ab

50.7 ± 0.6^l

20.5 ± 0.1^a

14.3 ± 0.0^a

61.7 ± 0.2ⁿ

103.3 ± 1.3^k

25.3 ± 0.2^m

35.6 ± 0.1^m

22.6 ± 0.0^l

62.1