| 释义 |
semi-ˈaxis
[semi- 7 b.]
The half of the axis of an ellipse, etc.
1743Phil. Trans. XLII. 360 The Semiaxis of the Spheroid. 1816Playfair Nat. Phil. II. 215 If a fixed star had an annual parallax that was sensible, it would appear to describe an ellipsis, of which the greater semi-axis was equal to that parallax. 1866Herschel Fam. Lect. Sci. v. §40. 213 The period of their mutual circulation may be stated at about ninety-six years, and the semiaxis of their mutual ellipse in angular measure at 4{pp}·8. 1867Smyth Sailor's Word-bk., Mean Distance, the average distance of a planet from the sun; it is equal to half the longer axis of the ellipse, and hence is..termed the semi-axis-major. |