Читать книгу Liquid Crystals - Iam-Choon Khoo - Страница 55

We now consider the process of director axis reorientation by an external static or low‐frequency field. Optical field effects are discussed in Chapter 6. The following examples will illustrate some of the important relationships among the various torques and dynamical effects discussed in the preceding sections. We will consider the magnetic field as it does not involve complicated local field effects and other electric phenomena (e.g. conduction). The electric field counterparts of the results obtained here for the magnetic field can be simply obtained by the replacement of Δχ ^m H ² by ΔεE ² (cf. Eqs. [3.26] and [3.29]).