Age and isotopic studies of some Pan-African granites from North-Central Nigeria     

O. Van Breemen  R.T. Pidgeon  P. Bowden 《Precambrian Research》1977,4(4):307-319

Twenty-nine Rb-Sr whole-rock isotopic analyses and three U-Pb zircon analyses on foliated granites and largely unfoliated charnockitic rocks indicate that the central part of the Pan-African belt in west Africa was characterised by intense orogenic plutonism. These data and Rb-Sr analyses on muscovite books from late cross-cutting pegmatites indicate that the peak of magmatic activity occurred 610 ± 10 m.y. ago.Initial ⁸⁷Sr/⁸⁶Sr ratios for the granitic and charnockitic rocks are in the range 0.7065–0.7125, and indicate a significantly older crustal component in the magmas.  相似文献   

A note on the equatorial anticyclogenesis     

Vojtěch Vítek  Rewiever O. Zikmunda 《Studia Geophysica et Geodaetica》1974,18(1):83-84

Summary The formative stage of low-latitude anticyclones is studied in terms of the simplified divergence theorem and vorticity equation.  相似文献   

The application of the upward continuity concept to induction studies     

Ebun Oni  O. Agunloye 《Pure and Applied Geophysics》1974,112(5):787-791

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Correlation and spectrum properties of the potential gradient and space-charge density in the atmospheric surface layer     

C. O. Oluwafemi  E. Ungethüm  S. Israelsson  E. Knudsen 《Pure and Applied Geophysics》1974,112(3):533-543

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The shape of a two-dimensional embryo on the basal face of ice in dependence on supersaturation     

Dana Lakomá  Reviewer O. Zikmunda 《Studia Geophysica et Geodaetica》1974,18(3):310-312

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About the Role of Quinones in the Action of Some Polyphenols on the Streaming of Protoplasm in Nitella sp. Cells     

D. J. Stom  G. G. Ivanova  G. V. Bashkatova  T. P. Trubina  O. M. Kozhova 《洁净——土壤、空气、水》1974,2(5):407-412

The concentration of phenols and quinones which stopped the protoplasmic movement in the Nitella cells after 15 min was determined. The quinones (β-naphthoquinone, α-naphthoquinone, p-benzoquinone, o-toluquinone, o-bromanil) stopped the protoplasmic movement in the concentration of (1 3) 10^?4 M, phenols (m-cresol, p-cresol, hydroquinone, guaiacol, phenol, gallic acid, pyrogallic acid, resorcinol) in the concentration of (0.2 5) 10^?2 M, except catechol – 2 10^?3 M. Very high toxicity of catechol and in the prolonged experiments (3 hours) also of hydroquinone is connected with the action of quinonoid productions of its oxidation. This suggestion is confirmed by the experiments:

• – by adding the phenol solutions to Nitella shoots (catechol, hydroquinone, resorcinol) we observed the greatest increase of oxygen absorption in case of catechol (86%), less in case of hydroquinone (38%), and for resorcinol oxygen absorption practically remained on the control level;
• – the action of catechol, hydroquinone and p-benzoquinone did not take place in the presence of glutathione and cysteine (but not cystine and oxidated glutathione);
• – diethyldithiocarbamate as an inhibitor of o-diphenoloxidase reduced the ability of catechol solutions to stop the protoplasmic movement;
• – the low concentrations of benzoquinones were able to stop the protoplasmic movement;
• – for stopping the protoplasmic movement under the prolonged time of incubation from 15 min to 3 hours there was necessary a lower concentration of solutions of hydroquinone and catechol in comparison with resorcinol.

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Ultrametamorphism and melting of a continental margin: The Rio de Janeiro Region,Brazil     

O. H. Leonardos Jr.  W. S. Fyfe 《Contributions to Mineralogy and Petrology》1974,46(3):201-214

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Ernst Cloos, 1898–1974     

O. M. Phillips 《International Journal of Earth Sciences》1974,63(3):1279-1280

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A simple geodetic imaginary experiment and its consequences for weight-determination and determination of systematic errors in geodetic adjustments     

O. Remmer 《Journal of Geodesy》1974,48(2):165-170

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Control of geochemical error through sampling and subsampling diagrams     

C.O. Ingamells 《Geochimica et cosmochimica acta》1974,38(8):1225-1237

Sampling and subsampling diagrams provide a means of visualizing and controlling sampling error during analysis of mixtures, especially those in which a minor constituent contributes heavily to assay values. The model employed refers each sampling problem to an idealized mixture of two constituents which has the same sampling or subsampling characteristics as the real mixture to be sampled. A procedure for calculating and constructing such diagrams depends on appropriate use of both Gaussian and Poisson statistics. The argument is simplified by combining the two statistical models.  相似文献