Biology Reference
In-Depth Information
198
Figure 8-2.
Plots of J
1
2
(x), J
2
2
(x), J
3
2
(x) and J
4
2
(x) for 0 < x < 8.
X-RAY DIFFRACTION PATTERN OF HELICAL LINE
In three-dimension, the equations which define a right-handed helix are:
and
where r is the radius of the helix, and P its pitch. The helical axis is along
the z-axis (Fig. 8-3). For a left-handed helix, the only change is to insert a
minus sign in front of r for the equation of y, i.e.
