| 释义 |
additive, a. and n.|ˈædɪtɪv|
[ad. L. additīv-us, f. addit- ppl. stem of add-ĕre to add; see -ive.]
A. adj.
a. Characterized by, or tending to, addition; to be added.
1699in Phil. Trans. XXI. 352 Additive Ratio is that whose Terms are dispos'd to Addition, that is, to Composition. 1751Chambers Cycl. s.v., Suppose the line ac divided in the points b and x, the ratio between ab and bx is additive; because the terms ab and bx compose the whole ax. 1833Sir J. Herschel Astron. v. 202 The quantity by which the true longitude of the earth differs from the mean longitude..is additive during all the half-year. 1840Carlyle Heroes iv. (1858) 279 The general sum of such work is great; for..all of it is additive, none of it subtractive.
b. Chem. Applied to a product, process, etc., characterized by addition (see addition n. 7).
1872Jrnl. Chem. Soc. XXV. 1008 Aromatic additive compounds. 1875Bloxam Chem. (ed. 3) 84 The carbonates may be expressed either by additive formulæ, showing the bases which combine with carbonic acid to produce them, or by substitutive formulæ. 1876Jrnl. Chem. Soc. XXIX. i. 338 The Laws which regulate Direct Additive Reactions. 1899M. M. P. Muir Wand. Atoms 101 Compounds..that are produced by the addition of an atom, or atoms, to the molecules of a compound..are named additive compounds. 1906Jrnl. Chem. Soc. XC. i. 729 The oxidation of amines is initially an additive process.
c. Of a process of colour reproduction in which the primary colours are superimposed one upon another.
1906E. J. Wall tr. König's Natural-Color Photogr. ii. 71 The additive methods of three-colour photography by optical synthesis. 1932Hardy & Perrin Princ. Optics xiv. 314 Colors combined in this manner obey the laws governing the addition of stimuli. This is therefore called the additive method of combining colors. 1935Discovery July 190/1 We can recompose colour either by adding primary coloured lights to black (by projection on to a screen in a dark room), or by subtracting primary coloured lights from a white light..containing all colours... Processes can thus be classified as additive or subtractive.
d. Examples of other technical uses.
1931L. H. C. Tippett Meth. Statistics iv. 67 The Additive Nature of χ2. A useful property of χ2 is that several values can be added together. 1939Brit. Jrnl. Psychol. July 14 If mild mental impairment were inherited by multiple Mendelian additive factors, the sibs should regress towards the norm. 1946C. E. Weatherburn First Course Math. Statist. 177 (heading) Additive property of chi-square. 1959P. B. Medawar in Listener 17 Dec. 1068/2 The word ‘additive’ refers to a particular pattern of co-operation or interaction between genes. An additive pattern of interaction implies (amongst other things) that there will be no such thing as hybrid vigour in respect of intelligence.
B. n. Something that is added; esp. (in various technical uses) a substance added (to a mixture, alloy, etc.) in order to impart specific qualities to the resulting product. Now esp. a substance added to food: see food additive s.v. food n. 8.
1945Electronic Engin. XVII. 516/1 The use of the monomeric styrene..as an additive to the solution of the polymer in solvent. 1948Economist 31 July 192/2 The supply of ‘additives’ for petroleum products. 1949E. A. Nida Morphology (ed. 2) iv. 103 Such bound forms are..nonclitics—additives, replacives, subtractives. 1950U.S. Congr. House Delaney Rep., Select Comm. Chemicals in Food (1951) 838 The use of additives which lead to a significant decrease in nutritive value should not be permitted. 1959Times 27 Apr. (Suppl. Rubber Ind.) p. viii/3 In road building it is a valuable additive to road surfacing materials. 1969Times 3 Mar. 5/6 The Swann committee..is considering the question of the possible dangers of additives in animal foods. 1984M. Hanssen E for Additives 8 So that foods can be moved from country to country within the Common Market, a list of additives that are generally recognised as safe has been introduced.
Add:[B.] 2. Comb. additive-free.
1975Business Week 17 Mar. 82/2 But these additive-free materials are difficult for converters to handle. 1982D. Canter et al. Cranks Recipe Book (1985) 12 James More-Molyneux, whose ready response resulted in Loseley becoming one of the largest suppliers of additive-free yoghourt and ice-cream for the whole of the south of England. 1990D. Mabey et al. Thorsons Organic Consumer Guide i. i. 27 Organic food should be additive-free, but not all additive-free produce is organic.
▸ Genetics. Designating genes whose effects on the phenotype are cumulative, with no one allele or gene being dominant or epistatic; of or relating to the effects of such a gene.
[1912Amer. Naturalist 46 311 This is exactly what Mendelian theory calls for on the assumption that several factors, each alike in effect, their effects being additive, are responsible for the parental differences.] 1936Amer. Naturalist 70 66 Many of the quantitative genes appear to be additive. 1939Brit. Jrnl. Psychol. July 14 If mild mental impairment were inherited by multiple Mendelian additive factors, the sibs should regress towards the norm. 1988M. Levitan Textbk. Human Genetics (ed. 3) xv. 342 The number of dermal ridges (in fingerprints) appears to be similarly determined by a relatively small number of additive loci. 2004J. R. Gillespie Mod. Livestock & Poultry Production (ed. 7) ix. 193 Heritability is the proportion of the total variation (genetic and environmental) that is due to additive gene effects. |