| 释义 |
ˈup-stroke
Also upstroke.
[up- 2 + stroke n.1]
1. dial. The upshot, end, or conclusion.
1828–in Eng. Dial. Dict. (Yks., Lancs., Derby, Linc.).
2. A stroke delivered upwards.
1828Gardener's Mag. III. 30 The air which enters from the valves by the up-stroke of the bellows. 1883Encycl. Brit. XVI. 447/2 When the up-stroke is being made..the piston is forced to make part of a revolution.
3. The upward stroke of a pen, etc.
1848Dickens Dombey lix, [She] clutches the money tight until a receipt..is duly signed, to the last up-stroke. 1856Mrs. Browning Aur. Leigh i. 847 Some upstroke of an alpha and omega. 1898Allbutt's Syst. Med. V. 822 In the irritable heart of young adults the upstroke in the sphygmogram is brisk and high.
4. Physiol. The part of a nerve impulse when the action potential is becoming more positive.
1974Nature 4 Jan. 69/2 The upstroke of the action potential is considered the result of a Hodgkin cycle. 1979Sci. Amer. Sept. 65/2 The depolarizing upstroke of the action potential is produced mainly by the inflow of sodium ions into the terminal. |