| 释义 |
ionization2|ˌaɪənaɪˈzeɪʃən|
[f. ion + -ization.]
1. The state of being ionized, or the process of ionizing.
1891G. F. Fitzgerald in Rep. Brit. Assoc. Adv. Sci. 1890 327, I object to the term dissociation as applied to the ions in an electrolyte... I would..appeal to both sides to adopt some neutral term such as ‘ionisation’ to express the state of ions in electrolytes. 1898Nature 8 Dec. 142/1 The measurements of the ionisation produced by Röntgen rays in fourteen gases showed that the ionisation was connected with the chemical composition in a very simple manner. 1908Westm. Gaz. 13 Mar. 2/1 Paulsen urges that the aurora is due to an immense ionisation of the upper layers of the air. 1926A. S. Eddington Internal Constitution of Stars i. 10 In the actual conditions of a star the ionisation is not quite complete. 1938R. W. Lawson tr. Hevesy & Paneth's Man. Radioactivity (ed. 2) i. 12 This kind of ionization of a gas, in which the ions initially produced gain sufficient energy by their acceleration in the electric field to produce fresh ions by collision, is called ‘ionization by collison’. 1947Glasstone Elem. Physical Chem. xiii. 422 It is essential to distinguish between ‘dissociation’ and ‘ionization’... The term ‘ionization’ applies to the total number of ions, irrespective of whether they are free or are held in ion-pairs. 1962Newnes Conc. Encycl. Electr. Engin. 161/2 The ionization of an atom by the removal of an outermost electron (or electrons) requires a definite amount of energy.
2. Med. = cataphoresis a.
1908Practitioner June 785 The modern zinc mercury ionisation treatment is a very definite way of directly applying powerful drugs to a diseased area. 1909[see iontophoresis]. 1934E. P. Cumberbatch Lect. Med. Electr. iii. 32 Ionization is a form of treatment in which ions possessing therapeutic properties are made to migrate into the body by the agency of electro-motive force. 1944E. B. Clayton Electrotherapy xi. 171 The patient should receive the ionisation reclining on a couch. 1960B. Savage Pract. Electrotherapy iv. 63 Histamine ionization is used whenever there is need for a marked increase in local circulation.
3. Comb.: ionization chamber, an instrument for measuring the intensity of ionizing radiation by collecting and measuring the charge on the ions which the radiation produces in a volume of gas; ionization constant Physical Chem. = dissociation constant (dissociation 2); ionization current, an electric current arising out of the movement, under the influence of an electric field, of ions and electrons produced in a gas; ionization energy = ionization potential; ionization gauge, an instrument for measuring the pressure in an evacuated vessel by ionizing the residual gas and measuring the resulting ionization current; ionization potential, the potential difference through which an electron must be accelerated in an electron impact experiment, or the energy required, to remove an electron in its lowest energy state from an atom or molecule of a gas.
1904Phil. Mag. VIII. 721 In Rutherford's experiment..the radioactive material was scattered over the floor of the ionization chamber. 1919J. A. Crowther Ions, Electrons & Ionizing Radiations ii. 15 The gas under investigation is contained in a metal box which is connected to earth... The box and its electrodes forms what is known as an ionization chamber. 1945Electronic Engin. XVII. 405 These experiments were carried out by means of ionisation chambers, like most of the early investigations on cosmic rays. 1966McGraw-Hill Encycl. Sci. & Technol. VI. 92/1 If the voltage is too low, the electron avalanche never builds up, and the [Geiger] counter operates only as an ionization chamber (a device which gives the total ionization produced in the gas) or proportional counter, in which the output pulses are much smaller.
1904T. S. Moore in R. A. Lehfeldt Electro-Chem. I. ii. 101 For binary electrolytes, in comparing the ionisation-constants, we are comparing the concentration necessary to produce a given degree of dissociation. 1924J. R. Partington in H. S. Taylor Treat. Physical Chem. I. xi. 538 The ionization constant of water..increases very rapidly at lower temperatures, passing through a maximum about 218°. 1972Moeller & O'Connor Ions in Aqueous Systems iv. 74 Inasmuch as numerical values for ionization constants are available for many weak acids and bases, it is possible to calculate ion concentrations in solutions containing these substances under a variety of conditions.
1902Phil. Mag. IV. 375 The time taken to pass over 100 divisions of the scale is taken by a stop-watch. The rate of movement is a measure of the ionization-current between the plates. 1956Hine & Brownell Radiation Dosimetry i. 18 The determination of dose in roentgens requires the measurement of an ionization current under saturation conditions.
1928F. J. Fuchs tr. Gerlach's Matter, Electr., Energy v. 69 On account of its large diameter and high ionization energy.., this singly charged helium atom appropriates to itself very rapidly a second electron. 1940Glasstone Text-bk. Physical Chem. i. 52 The ionization energy is the work required to remove an electron from its lowest level to infinity. 1973Sci. Amer. Feb. 91/1 Each kind of atom has a different ionization energy depending on the number of protons, neutrons and electrons it has.
1934Physical Rev. XLV. 611/2 The pressure within the vacuum chamber as recorded by an ionization gauge..is often less than 10-6 mm Hg. 1966McGraw-Hill Encycl. Sci. & Technol. VII. 253/2 In another type of ionization gage, the gas is ionized by high-energy alpha particles emitted by a radioactive source such as radium.
1914Phil. Mag. XXVIII. 753 (heading) Note on the ionization potential of mercury vapour. 1927Physical Rev. XXIX. 287 The second ionization potential of lithium, the amount of work required in order to remove one further electron from the singly ionized lithium atom, Li+, in the normal state 1S, has not been directly determined by the method of electron impact. 1935J. N. Friend Text-bk. Physical Chem. II. viii. 362 Upon raising the P.D. still more, gaseous ionisation occurs, the lowest potential producing this being known as the ionisation potential. 1950W. J. Moore Physical Chem. x. 262 The alkali metals have low ionization potentials; the inert gases, high ionization potentials. 1972C. E. Brion in A. Maccoll Mass Spectrometry iii. 61 PES [sc. photoelectron spectroscopy] is a detector of direct photoionisation and as a result has proved to be the best and most prolific source of both inner and outer ionisation potentials. |