torus
环状体,环状线,环状,环形物
Definitions
- 1
plural to·ri [tawr-ahy]. /ˈtɔr aɪ/.
- : Architecture. a large convex molding, more or less semicircular in profile, commonly forming the lowest molding of the base of a column, directly above the plinth, sometimes occurring as one of a pair separated by a scotia and fillets.
- : Geometry. Rarely an·chor ring .a doughnut-shaped surface generated by the revolution of a conic, especially a circle, about an exterior line lying in its plane.the solid enclosed by such a surface.
- : Botany. the receptacle of a flower.a thickening of the wall membrane in the bordered pits occurring in the tracheid cells of the wood of many conifers.
- : Anatomy. a rounded ridge; a protuberant part.
Examples
If the surface does not have a boundary, like a torus, the first cut must begin and end at the same point.
A hollow torus can be cut twice — once around the tube and then along the resulting cylinder — so by this definition, it has two holes.
That there are two one-dimensional loops from which all others can be built means that the Betti number of the torus in dimension one is 2, the same as the number of Riemann’s cuts.
At each corner of the black marble bases, and touching the torus of the column, the head of a bird or animal has been carved.
The lateral arcades have similar capitals but only one torus.
At this time each pistil loosens from the torus and can be easily removed, especially if some animal touch the hooks.
The slender torus usually distinguished the eight-branch Plantagenet type, and its use here for simple diagonals is an exception.
As time went on profiles deteriorated, sharp prismatic molds succeeding to the virile torus, or molds fluid and vague.