| 释义 |
retarded, ppl. a.|rɪˈtɑːdɪd|
[f. retard v. + -ed1.]
1. a. Checked: impeded; delayed.
1810Crabbe Borough xxiii. 320 The timid girls..Dip the small foot in the retarded brine. 1815J. Smith Panorama Sci. & Art I. 398 Retarded motion is when the velocity continually decreases. 1871Darwin Desc. Man II. xvii. 259 Male birds have acquired ornamental plumes at the cost of retarded flight. 1899Allbutt's Syst. Med. VII. 765 The first fits occur during retarded dentition.
b. Psychol. Orig., applied to children whose mental or educational progress lags behind that of their contemporaries to a significant degree; later extended to anyone with a measured intelligence less than some value that is itself below the average, esp. when attributed to impaired learning or maturation in childhood and youth. Hence ellipt. as n.
1895G. E. Shuttleworth Mentally-Deficient Children ii. 19 Such children are also described as ‘backward’, or of ‘retarded mental development’—terms corresponding to the ‘Enfants arriérés’ of French writers..and the ‘Tardivi’ of the Italians. 1910J. D. Heilman (title) A clinical study of one thousand retarded children in the public schools of Camden, New Jersey. 1919L. M. Terman Measurement of Intelligence i. 24 (heading) The intelligence of retarded children usually overestimated. 1937C. L. Burt Backward Child iv. 79 In the following pages, the word ‘retarded’ will be used to mean any child whose educational ratio falls below 85 per cent. 1951H. Loewy Retarded Child (rev. ed.) i. 14 Retarded children can be put into two broad classifications from the teaching point of view: (1) The child with a mental defect. (2) The mentally defective child. 1956H. Michal-Smith Mentally Retarded Patient p. vii, The mentally retarded of all ages are subject to illness as are other people. 1960Tansley & Gulliford Educ. Slow Learning Children ii. 44 If his reading age is two years below his mental age he is considered retarded and special efforts must be made to get him ‘working to capacity’. 1967Brussel & Cantzlaar Chamber's Dict. Psychiatry 144 A mentally retarded person is one whose intelligence quotient..is below 70. 1973La Cruz & La Veck (title) Human sexuality and the mentally retarded. 1975Balthazar & Stevens Emotionally Disturbed, Mentally Retarded vi. 87 Critical statements of the value of psychotherapy for the retarded. 1979Books & Bookmen Jan. 43/1 Of those who could be given reliable intelligence tests, thirty-two per cent were defective, with an IQ below fifty, and thirteen per cent were retarded, with an IQ between fifty and seventy. Fifty-five per cent were subnormal or normal, ie, with IQs above seventy.
2. Physics. Applied to parameters of an electromagnetic radiation field in which allowance is made for the finite speed of propagation of the radiation, so that the potential due to a distant source is expressed in terms of the state of the source at some time in the past.
1920Physical Rev. XV. 312 (heading) Note on the retarded potentials. 1929Mason & Weaver Electromagn. Field iv. 283, {ob}ρ{cb}, the so-called ‘retarded value’ of ρ, is given by {ob}ρ{cb} = ρ(x, y, z, t–r/c). 1941C. A. Coulson Waves viii. 141 We call t–r/c the retarded time. 1962Corson & Lorrain Introd. Electromagn. Fields xiv. 493 The retarded position [z] is less than z by a factor of 1/{ob}1 + (v/c){cb}. 1974Encycl. Brit. Macropædia VI. 660/2 The exact potentials corresponding to a point charge..are not obtained by substituting the total charge for the volume integral indicated in the retarded potentials. The problem arises because of the finite velocity of field propagation, so that the integral of the retarded charge density over space is not in general equal to the total charge. 1975D. M. Cook Theory Electromagn. Field xiv. 402 A potential of this form is referred to as a retarded potential because the potential at time t is determined by the state of the charge at the so-called retarded time t′. |