| 释义 |
isopleth|ˈaɪsəʊplɛθ|
[ad. Gr. ἰσοπληθ-ής equal in quantity, f. πλῆθος multitude, quantity.]
1. [ad. G. isoplethe (C. A. Vogler Anleitung zum Entwerfen graph. Tafeln (1877) i. 7).] A line (either imaginary or on a map or diagram) connecting points for which some chosen quantity has the same value, the points (if on a diagram) being defined by two variables of which one is usually distance and the other either distance or time.
1909in Cent. Dict. Suppl. 1911N. Shaw Forecasting Weather 4 Isobars are isopleths of pressure, isotherms are isopleths of temperature, and so on. 1935Geogr. Jrnl. LXXXV. 145 Isopleths of population density are drawn. 1950Conrad & Pollak Methods in Climatol. (ed. 2) iii. 69 The curves z= const., called isopleths, thus show the relationship of the two variables x and y only for selected values of the third variable z, which is constant for each curve. 1957G. E. Hutchinson Treat. Limnol. I. ix. 630 Three days later a still more striking deflection of the oxygen isopleths downward at the upper end of the basin was noted. 1971Sci. Amer. Sept. 92 (caption) Mean radiation of the earth is portrayed by isopleths..that give the net radiation in terms of calories per square centimeter per minute.
2. Physical Chem. A line or surface (in a diagram) joining points that represent mixtures of the same composition.
1924G. Edgar in H. S. Taylor Treat. Physical Chem. I. ix. 400 Assume a complex containing 60 per cent phenol to be warmed from 10° to 70°; the process can be followed by drawing a line of equal concentrations, ab, called an isopleth. 1950W. J. Moore Physical Chem. vi. 136 Let us follow the sequence of events as the pressure is gradually reduced along the line of constant composition, or isopleth, xx′. 1951J. E. Ricci Phase Rule iii. 59 The representation of the melting point region may be completed by a constant composition section, the isopleth shown in Fig. 3–12.
Hence ˈisoplethal |-pliːθəl| a., carried out or occurring at constant composition.
1924G. Edgar in H. S. Taylor Treat. Physical Chem. I. ix. 411 The general diagram..may be used to illustrate the effect of isothermal and isoplethal changes. 1951J. E. Ricci Phase Rule ix. 189 Isoplethal or Synthetic Methods. These involve the measurement of the temperature of phase transition or of the curve of a miscibility gap, upon complexes of known composition. |