349 / | HD | LIQUID CRYSTAL CELLS, ELEMENTS AND SYSTEMS |
167 | DF | WITH SPECIFIED NONCHEMICAL CHARACTERISTIC OF LIQUID CRYSTAL MATERIAL {6} |
177 | DF | .~ Within nematic phase {2} |
179 | DF | .~.~ Twisted (or chiral) nematic or supertwisted nematic {2} |
181 | .~.~.~ Having particular birefringence or retardation |