| 释义 |
cnicnode Math.|ˈnɪknəʊd|
[f. L. cnīcus, cnēcus safflower = Gr. κνῆκος a plant of the thistle kind + L. nodus knot, node.]
A conical point, a point where tangents form a cone of the second order. Also ˈcnictrope (see trope), the reciprocal of a cnicnode.
1869Cayley Math. Papers (1893) VI. 330, I take account of conical and biplanar nodes, or, as I call them, cnicnodes, and binodes. Ibid. 334 Consider a surface having the cnicnode C = 1, and the reciprocal surface having the cnictrope C′ = 1. 1870Ibid. (1894) VII. 246 There may be on the nodal curve points which, in the classification of the surfaces, must be counted as cnicnodes. 1887Encycl. Brit. XXII. 669/1 As regards isolated singularities, it will be sufficient to mention the point singularity of the conical point (or cnicnode) and the corresponding plane singularity of the conic of contact (or cnictrope). |