| 释义 |
eutrophic, a. and n.|juːˈtrɒfɪk|
[f. next + -ic.]
A. adj.
1. Med. Tending to promote nutrition.
2. Of a lake, swamp, etc.: (over-)rich in organic or mineral nutrients and having as a result an excessive growth of algæ and other plants, with depletion of oxygen and consequent extinction of animal life; spec. (see quot. 1931). Hence eutrophiˈcation, the process of becoming eutrophic.
1931R. N. Chapman Animal Ecol. xvi. 305 The eutrophic type of lake is characterized by the paucity or absence of oxygen in the bottom waters. 1947A. D. Hasler in Ecology XXVIII. 383/1 Enrichment of water, be it intentional or unintentional, is called eutrophication... In this paper eutrophication will be interpreted in the broadest sense; namely, lake enrichment owing to any and all nutritive substances. Ibid. 390/1 Eleven oligotrophic and dystrophic lakes have taken on eutrophic characteristics since comparatively recent times. Most rapid eutrophication has taken place in regions where there are deposits of postglacial clay;..the process has been accelerated by ‘cultural influences’ such as effluents from flax retting plants,..barnyards, fertile soil, urban settlements. 1959J. Clegg Freshwater Life (ed. 2) Pl. 2 (caption) An evolved lake in which eutrophic conditions occur. Ibid. xix. 317 Large reservoirs..exhibit all the characteristics of a typical eutrophic lake. 1967Technology Week 23 Jan. 70/3 Lake Erie's eutrophication. 1968Observer 17 Nov. 9/4 Decaying plant matter consumes all the oxygen in the water, which becomes lifeless... This process of ‘eutrophication’ (or over-fertilisation) has overtaken at least 40 lakes in Britain and the US. 1970Nature 11 Apr. 101/1 The characteristic of a eutrophic lake is the way in which the bottom layers are depleted of oxygen during the summer as organic matter sinks to the bottom and decays. 1970Motor Boat & Yachting 16 Oct. 25/1 Eutrophication (dense growth of weed) tends to occur in enclosed areas of water.
B. n. A eutrophic medicine.
1884Syd. Soc. Lex. s.v., The chief eutrophics are mercurials, the preparations of iodine, bromine, etc. |