| 释义 |
sequential, a.|sɪˈkwɛnʃəl|
[f. late L. sequentia sequence n.: see -al1.]
1. a. That follows as a sequel to. Of two or more things: Forming a sequence.
1854Chamb. Jrnl. II. 82 A brief resumé of these thronging reminiscences must necessarily precede the telling of the story sequential to them. 1899Allbutt's Syst. Med. VIII. 209 Mental action, though disorderly and not sequential to the question put. 1906Hibbert Jrnl. Oct. 219 These two books, while not sequential, are closely related.
b. Path. Following as a secondary affection; occurring as a sequela to a previous disease.
1822–29Good's Study Med. (ed. 3) V. 230 Sequential Labour..Sequential, or after-pains as they are ordinarily called. 1904Brit. Med. Jrnl. 10 Sept. 606 Inflammatory œdema is brought under the heading of phlegmonous laryngitis, primary and sequential.
c. Resultant, consequent.
1899W. M. Davis in Geog. Jrnl. (R.G.S.) XIV. 487 ‘Initial’ is therefore a term adapted to ideal rather than to actual cases, in treating which the term ‘sequential’ and its derivatives will be found more appropriate. 1900J. Orr in U.P. Mag. Feb. 62/2 With these divisions of opinion on the nature of the Church are connected many sequential differences.
d. sequential induction (Biochem.): the formation in sequence of a group of related enzymes, consequent upon the induction of the first enzyme of the series (see quot. 1953).
1953M. Cohn et al. in Nature 12 Dec. 1096/2 We..propose the following terms and designations... The exposure of an organism to a single inducer which is also a substrate may result in the induction of a sequence of enzymes, since the metabolism of the primary, exogenous inducer gives rise to the formation of a succession of intermediary metabolites each of which in turn serves as an inducer for the enzyme which converts it into the next member of the metabolic chain. This phenomenon is termed ‘sequential induction’ (simultaneous or successive adaptation). 1968H. Harris Nucleus & Cytoplasm vi. 118 We have glimpses of this kind of organization in the phenomenon of ‘sequential induction’ (induction en chaîne) of enzymes in bacteria. 1971Bacteriol. Rev. XXXV. 89/2 A sequential induction is characterized by a shift in the chemical nature of the inducer.
2. a. That is characterized by the regular sequence of its parts; continuous.
1844‘A. Wallbridge’ (title) The Sequential system of Musical Notation: a proposed new method of writing Music. Second edition. 1849(title) The sequential book of church music. No. 1. 1862S. Lucas Secularia 67 If the history of man has been in the main sequential. 1879Carpenter Mental Phys. i. viii. 346 The complete engrossment of the consciousness by a particular series of Cerebral changes..enables those changes to proceed with more sequential regularity. 1887Pall Mall Gaz. 8 Nov. 4/2 There is in this country ‘no sequential teaching’.
b. Computers. Of, pertaining to, or designating various aspects of a computer system and its control programming that operate or are utilized serially; sequential search, a search through a data list or file that is carried out serially.
1951Proc. IRE XXXIX. 276/2 Sequential control, the manner in which instructions to a digital computer are set up in sequence and are fed consecutively to the computer during the solution of a problem. 1964T. W. McRae Impact of Computers on Accounting iii. 53 A computer..carries out each of these operations in automatic sequence under the control of the computer programme. This particular characteristic is known as ‘sequential processing’. 1965Information & Control VIII. 159 (heading) Discrete sequential search. 1969P. B. Jordain Condensed Computer Encycl. 447 Once written, a sequential file has to be read in the same order (or sometimes in the inverse order) in which it has been written. 1970O. Dopping Computers & Data Processing x. 133 The magnetic tape can be called a sequential access memory, or serial access memory, because the records must be written and read in sequence. 1973C. W. Gear Introd. Computer Sci. ii. 44 We refer to the set of input cards as a sequential data set because it is possible to read a card only after the preceding card has been read. 1979J. E. Rowley Mechanised In-House Information Syst. i. 26 Any search must process the complete tape, from start to end, seeking matches between terms, i.e. a sequential search.
3. Pertaining to sequency of thought. rare— 1.
1853Ruskin Stones Ven. III. ii. 38 God..has given to the man whom he means for a student, the reflective, logical, sequential faculties.
4. Mus. Of the nature of a sequence.
1889H. A. Harding Analysis of Form 5 A sequential passage leads to an inverted dominant pedal point. 1891Prout Counterpoint (ed. 2) 100 The sequential character of the treble and tenor is maintained in the added alto part.
5. Television.
a. Of or pertaining to the normal method of scanning a television image, in which all the lines are traversed in the same direction, with a rapid, blanked fly-back after each.
1940Chambers's Techn. Dict. 759/1 Sequential scanning, scanning in which the spot traverses each line in the same direction, returning rapidly from the end of one line to the beginning of the next. 1942Electronics Apr. 164/1 System 2 employs sequential scanning in order to eliminate interline flicker. 1966G. H. Hotson Television Receiver Theory i. 5 A sequential raster..would be set up by drawing 625 lines one under the other. 1967H. A. Cole Basic Television iii. 26 Provided that the rate of sequential scanning is high enough, the eye can be successfully ‘tricked’, by reason of the persistence of its vision, into believing that a very rapidly renewed image on the viewing screen has in fact been there all the time.
b. Of, pertaining to, or designating various systems of colour television in which picture information for the primary colours is transmitted successively in quantities corresponding to a dot, line, or field. Cf. dot- (also field-, line-) sequential system s.v. dot n.1 5 f, field n. 21, line n.2 32.
1947Electronics Jan. 72/2 The sequential system is characterized by the fact that the transmitted signal contains information about one primary color only at any instant of time. 1951Proc. IRE XXXIX. 1195/1 In the case of field-sequential or line-sequential presentation, step-wise switching from color to color is desired. In the case of dot-sequential presentation, sine-wave switching by circular deflection with uniform angular velocity is preferred. 1975D. G. Fink Electronics Engineers' Handbk. xx. 12 The field sequential system employs a monochrome television camera, with a color-scanning disk mounting near the focal plane... The video signal derived from the camera tube thus consists of sequential color fields in the order that the primary light filters appear in front of the camera tube.
6. sequential circuit (Electronics), a logic circuit whose output depends on the order or timing of the inputs.
1954D. A. Huffman in Jrnl. Franklin Inst. CCLVII. 165 In a circuit having secondary relays, the possibility of a ‘memory’ exists since the states of operation may not uniquely determine the output transmissions. A circuit having secondary relays will be called a sequential circuit. 1969J. J. Sparkes Transistor Switching iv. 93 In combinational and sequential circuit diagrams it is usual to use special symbols. 1975D. G. Fink Electronics Engineers' Handbk. xxiii. 41 In some cases problems exist in sequential circuits when a circuit action depends critically on which relay or logic element completes its operations first.
Hence seˈquentially adv.; seˈquentialism rare (see quot. 1848); sequentiˈality, the quality of being sequential.
1656[see sequence n. 3]. 1848‘A. Wallbridge’ Council of Four Advt., Sequentialism: The new Musical Reform. Preparing for publication, the third edition of the Sequential System of Musical Notation. 1855Fraser's Mag. LI. 168 What common-place man..has not dreams more lively and more sequentially evolved than this cento of wire-drawn reflections? 1883Harper's Mag. LXVIII. 158 The story is remarkable for its fresh naturalness and sequentiality. 1891Prout Counterpoint (ed. 2) 45 We may now employ the same figure—especially sequentially—for several bars. |