| 释义 |
▪ I. ultracentrifuge, n.|ʌltrəˈsɛntrɪfjuːdʒ|
[f. ultra- 2 c + centrifuge n.]
A very high-speed centrifuge, now usu. generating over 100,000g, used to separate small particles and large molecules in a liquid and to determine their sedimentation rate (and hence their size).
1924Svedberg & Rinde in Jrnl. Amer. Chem. Soc. XLVI. 2678 In analogy with the naming of the ultra⁓microscope and ultra-filtration apparatus we propose the name ultra-centrifuge for this apparatus. 1939Ann. Reg. 1938 374 The ultracentrifuge showed the presence in plant juices of carbohydrates of well-defined molecular weight. 1948New Biol. V. 33 Tiny air-driven turbine ultra-centrifuges which rotate at speeds up to 5,000 revolutions per second, giving forces equal to half a million times that of gravity, will stratify many of the finest cell inclusions. 1968New Scientist 3 Oct. 6/3 A pilot plant for enriching uranium by the ultracentrifuge method. 1978H. McLeave Borderline Case (1979) xiii. 132 The laboratory..had everything, including..several ultracentrifuges.
Hence ˌultracentrifugal (stress variable) a., involving or employing an ultracentrifuge; ˌultracentrifugally (stress variable) adv., by means of an ultracentrifuge; with respect to the ultracentrifuge.
1930Jrnl. Amer. Chem. Soc. LII. 2904 The ultracentrifugal study of gelatin solutions has been fruitful in revealing the heterogeneous nature of the sols. 1943Jrnl. Exper. Med. LXXVII. 460 Gratia and Paillot had reported polyhedral bodies and ultracentrifugally purified material from jaundiced blood to be serologically unrelated to ultracentrifugally purified material from the blood of normal silkworms. 1953Jrnl. Amer. Chem. Soc. LXXV. 67/2 Recently they succeeded in preparing an electrophoretically and ultracentrifugally homogeneous mucoprotein. 1962M. Rabaey in A. Pirie Lens Metabolism Rel. Cataract 310 Ultracentrifugal analysis permitted us to classify this protein as a member of the so-called group of β-crystallins. 1977Lancet 8 Oct. 742/1 A typical ultra⁓centrifugal scan and the distribution of IgE in the corresponding fractions is shown.
▪ II. ultraˈcentrifuge, v.
[f. prec. n.: cf. centrifuge v.]
trans. To spin in an ultracentrifuge. Chiefly as ultraˈcentrifuged ppl. a., ultraˈcentrifuging vbl. n. Also ˌultracentrifuˈgation, the action or process of ultracentrifuging.
1934Proc. Soc. Exper. Biol. & Med. XXXI. 707 (heading) Effect of ultracentrifuging on Paramecium. 1936Trans. Faraday Soc. XXXII. 301 In this case again, analogous to those of viscometry and ultracentrifugation, the dilutest solutions yield the clearest result. 1946Nature 5 Oct. 488/2 Virus can be separated by differential ultracentrifuging into fractions with widely different properties. 1947Ann. Rev. Microbiol. I. 364 Ultracentrifuged concentrates of virus. 1971Nature 18 June 447/1 The extract was spun at 25,000g for 20 min to remove large particles before being subjected to ultracentrifugation at 105,000g for 90 min to sediment out the microsomes and membrane fractions. 1974Ibid. 13 Dec. 605/2 The injection of adult mice with ultracentrifuged heterologous γ globulin induces immunological unresponsiveness to a subsequent injection of the globulin. 1977Lancet 8 Oct. 742/1 The distribution of radioactivity in a radiolabelled (125I) myeloma IgE preparation ultracentrifuged under identical conditions. |