| 释义 |
ˌtetrakis-hexaˈhedron
[f. Gr. τετράκις four times + hexahedron.]
A solid figure contained by twenty-four equal triangular planes, having the appearance of a cube with a low pyramid raised on each of its six faces. (In Cryst. belonging to the isometric system.) In Geom. the name is specially applied to the figure when the pyramids are of such a height that all the adjacent faces are equally inclined to each other, so that the figure meets the sphere circumscribing the fundamental cube at fourteen points. Also called tetrahexahedron (b), cube-pyramidion, and fluoroid.
1878Gurney Crystallogr. 86 A four-faced cube, or more technically a tetrakishexahedron. 1887Athenæum 10 Sept. 345/2 The new crystals are sharply defined cubes, of which some have the edges replaced by faces of the rhombic dodecahedron or of a tetrakishexahedron. 1895Story-Maskelyne Crystallogr. 195–6 The tetrakis-hexahedron..presents the aspect of a cube each face of which is surmounted by an obtuse pyramid, and it may, on this account, be termed the cube-pyramidion... The figure is a twenty-four-faced isoscelohedron. |