| 释义 |
balanced, ppl. a.|ˈbælənst|
[f. as prec. + -ed.]
1. lit.
a. Poised; so arranged, placed, or adjusted with a counterpoise, as to remain in equilibrium.
1611Cotgr., Balancé, Ballanced, weighed, peised. 1667Milton P.L. iv. 1000 The pendulous round Earth with ballanc't Aire In counterpoise. 1814Scott Ld. of Isles iii. xv, Loose crags..chance-poised and balanced, lay.
b. spec. Of a rudder or of the control surface of an aeroplane: see quots.
1869Daily News 12 June, The Cerberus has a balanced rudder. 1874S. J. P. Thearle Naval Archit. (Adv. Sci. ser.) iv. xx. 340 The balanced rudder revolves about an axis so situated that about two-thirds the area of the rudder is on the aft, and the remaining one-third on the fore side of the axis. 1920Flight 5 Aug. 867/2 The aeronautical engineer needs some simple rule for the design of balanced control surfaces. 1922Flight XIV. 344/1 Balanced ailerons are fitted to the top plane only. Ibid. The tail plains [sic]..consist of..two balanced elevators hinged to the stabiliser, and a balanced rudder. 1950Gloss. Aeronaut. Terms (B.S.I.) i. 34 Balanced surface, a control surface in which the aerodynamic hinge moment opposing rotation has been reduced by so shaping it that part of the surface is forward of the hinge, or by fitting it to a balance tab, or by other means.
2. Having the opposed parts or tendencies so adjusted as to produce equilibrium or equality.
1592Daniel Compl. Rosam. (1717) 47 Thus stood I ballanc'd equally precise, Till my frail Flesh did weigh me down to Sin. 1727Swift Balance Eur. Wks. 1755 III. ii. 128 Now Europe's balanc'd, neither side prevails. 1870Jebb Sophocles' Electra Introd. 10 Contending and almost balanced claims. 1877Ruskin Laws Fesole i. ii, Every system is imperfect which pays more than a balanced and equitable attention to any one of the three skills.
3. a. Well arranged or disposed; stable in character by due proportion of parts.
1624Quarles Sion's Sonn. (1717) 349 The ruby portals of thy ballanc'd words Send forth a welcome relish. 1836J. Gilbert Chr. Atonem. iii. (1852) 60 Neither can it..operate with any weight upon a justly balanced mind. 1878T. Sinclair Mount 83 The birth of a balanced artist.
b. spec. Dietetics. Containing a suitable proportion of each type of nutriment required for adequate nutrition.
1908Sci. Amer. Suppl. 24 Oct. 267/2 The early summer dinner..of lamb and peas with a salad, bread and butter, and a little fruit perhaps, makes a good example of a well-balanced meal. 1912Delineator LXXX. 45 Problem of supplying a properly balanced menu. 1917Ladies' Home Jrnl. Nov. 56/2 She can't understand what is meant by a ‘balanced meal’. 1936Discovery Apr. 98/2 A balanced diet, not merely a copious one is indicated.
4. Logic. (See quot.)
1849Abp. Thomson Laws Th. §71 The middle [term] is said to be balanced when it is distributed in both premisses alike. The extremes of the conclusion are balanced when both alike are distributed. 1870Bowen Logic viii. 258 Moods..balanced as respects both Terms and Propositions.
5. Naut. Reefed with a balance-reef (see balance v. 16).
1750in Essex (Salem, Mass.) Inst. Hist. Coll. (1910) XLVI. 96 We were obliged to hand the jibb and lay too under ballanced mainsail. 1762–9[see balance v. 16]. 1802A. Ellicott Jrnl. 26 Nov. (1803) 256 We had to heave too under a ballanced main-sail.
6. Other techn. uses.
1902G. S. Newth Text-Bk. Inorg. Chem. (ed. 9) i. x. 88 Reactions of this order are known as reversible or balanced actions. 1904Goodchild & Tweney Technol. & Sci. Dict. 38/1 Balanced Steps, the method of arranging the steps of geometrical stairs to increase the going (width) at the small ends of the winders, and to give a better falling line to the handrail. 1918W. H. Eccles Wireless Teleg. (ed. 2) 489 Balanced Detectors, a term applied to an arrangement of opposed rectifying detectors for reducing the effects of strong Xs in receiving apparatus. 1924Roget Dict. Electr. Terms 17/1 Balanced load, a load in a three-wire system which is equally shared by the two sides, or in a polyphase system, where it is equally shared by the various phases. Ibid., Balanced modulator. 1929Wilson & Webb Mod. Gramophones & Electr. Reproducers ix. 180 There is no permanent magnetic pull on the armature when no signal is passing through the coil. This type is therefore known as a ‘balanced armature’. 1930Phillips & Tutt Mod. Gas Fitting xi. 341 The ‘Balance’ radiator is so called in that the air inlet and combustion products outlets are made continuous and ‘balanced’. 1933Edgcumbe & Ockenden Indust. Electr. Measuring Instr. xiii. 279 A strictly ‘balanced’ circuit is one in which the currents, voltages, and phase displacements are the same for each phase. 1938Fritsch & Salisbury Plant Form & Function v. 49 A mixture of ions in solution in such proportions that they exert no toxic effect is called a balanced solution. 1940L. Hartshorn Radio Freq. Meas. iii. 48 The potential of one terminal is always as much above that of the screen (earth) as that of the other is below it. This is known as the balanced condition. 1944Hackh's Chem. Dict. (ed. 3) 96/1 Balanced reaction, a reaction which can be made to proceed in either direction by variation of either temperature, pressure or concentration of the reactants. 1955Archit. Rev. CXVII. 93/2 Balanced-flue gas heaters are provided in the kitchens and serve the sink, lavatory basin and bath.
Add:7. Computing. Of a binary tree: such that for each node the left and right subtrees are of equal or approximately equal size, as measured by the number of levels or the number of nodes in each.
1962Symposium Symbolic Lang. Data Processing 156 A Balanced Tree is accomplished by filling the levels of the tree to completion, i.e., no new levels are to be initiated as long as there are vacant catenae available in the preceding level. 1973C. W. Gear Introd. Computer Sci. vii. 285 A balanced tree leads to fewer operations on the average if any item is equally likely to be referenced. 1976N. Wirth Algorithms plus Data Struct. iv. 195 The rule is expressed as a recursive procedure as part of Program 4.3 which reads the input file and constructs the perfectly balanced tree. 1984R. L. Kruse Data Struct. & Program Design v. 221 The algorithm..produces a binary search tree that is not always completely balanced. |