Related Experiment Video

Updated: Jun 20, 2026

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
06:24

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

Published on: October 31, 2019

Feedback-induced first-order Freedericksz transition in a nematic film

P Y Wang, H J Zhang, J H Dai

    Optics Letters
    |September 11, 2009
    PubMed

    More Related Videos

    Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light07:56

    Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

    Published on: September 20, 2017

    Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets06:26

    Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

    Published on: May 15, 2017

    Related Concept Videos

    Atomic Nuclei: Nuclear Relaxation Processes01:23

    Atomic Nuclei: Nuclear Relaxation Processes

    In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis. This...
    ¹H NMR: Interpreting Distorted and Overlapping Signals01:02

    ¹H NMR: Interpreting Distorted and Overlapping Signals

    Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
    As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
    Dielectric Polarization in a Capacitor01:31

    Dielectric Polarization in a Capacitor

    The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
    Induced Electric Dipoles01:28

    Induced Electric Dipoles

    A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
    Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
    Thermal Sigmatropic Reactions: Overview01:16

    Thermal Sigmatropic Reactions: Overview

    Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
    Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...
    Atomic Nuclei: Nuclear Spin State Population Distribution01:14

    Atomic Nuclei: Nuclear Spin State Population Distribution

    Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.