| 释义 |
con·cen·tra·tion
\ˌkän(t)sən.ˈtrāshən also -änˌsen-\ noun
(-s)
Etymology: com- + Latin centrum + English -ation
1. : the act or action of concentrating: as
a. : the bringing to a common center; especially : the assembling of troops in an area often as a prelude to military action
b. : a directing of the attention or of the mental faculties toward a single object
c. : an increasing of strength (as of a solute or a gas in a mixture) or a purifying (as of a mineral in ore) by partial or total removal of diluents, solvents, admixed gases, extraneous material, or waste (as by evaporation, diffusion, or selective flotation)
d. : the centering of a student's program of study in one department or field of learning in which he does work of advanced grade — compare distribution 1c
2. : a result of concentrating : a concentrated mass or thing: as
a. pharmacy : a crude active principle of a vegetable usually in the form of a powder or resin
b. : a group of artillery shells fired on a particular area within a limited time — compare barrage
3. of a solution, mixture, or dispersion : the relative content of a component (as dissolved or dispersed material) that may be expressed in percentage by weight or by volume, in parts per million, or in grams per liter : strength
4. : density 1
5. : a card game for two or more players in which a pack of cards is laid out card by card face down and at random, the skill of the game consisting of remembering the position of such cards as are briefly turned up in play — called also memory |