Figure 1.

Sample diffraction patterns from non-crystalline materials. (a) A well aligned polycrystalline specimen of E-DNA [poly(I-I-T).poly(A-C-C) (from Leslie et al., 1980 ▶)]. (b) A low-angle X-ray diffraction pattern from insect flight muscle, showing excellent sampling and d spacings in the range 48–387 Å with a c-axis repeat of 2320 Å (from AL-Khayat et al., 2004 ▶). (c) Wide-angle X-ray diffraction pattern from a sample of a diblock copolymer of oxyethylene (E) and oxybutylene (B) as E₇₆B₃₈ (where the subscripts denote the average numbers of repeat units) that had been crystallized after shearing in the melt (Fairclough et al., 2000 ▶). (d) High-angle X-ray diffraction pattern from magnetically oriented sols of PotatoVirus X, showing a helical repeat of about 34.5 Å (Stubbs et al., 2005 ▶).