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Quelques théorèmes de géométrie différentielle globale

Commentarii Mathematici Helvetici (1949-12-01) 22: 271-301 , December 01, 1949

By Lichnerowicz, André

2 Citations

No abstract available

Synthetic experiments in the benzopyrone series

Proceedings of the Indian Academy of Sciences - Section A (1949-11-01) 30: 216-222 , November 01, 1949

By Narasimhachari, N.; Seshadri, T. R.

2 Citations

Summary

A convenient method of providing confirmation of the constitution of carthamidin and isocarthamidin is to convert them into herbacetin and tangeretin. The earlier claim of Bargellini to have prepared herbacetin tetramethyl ether by the oxidation of 2-hydroxy-3:4:6:4′-tetramethoxy chalkone with alkaline hydrogen peroxide could not be supported. This reaction yields the corresponding benzalcoumaranone and not flavonol in agreement with the behaviour of analogous and simpler chalkones having a methoxyl group in the 6-position. An example is described where even a methyl group in that position brings about the same result. However by the action of amyl nitrite and hydrochloric acid carthamidin and isocarthamidin tetramethyl ethers yield the corresponding flavonol derivatives.

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Über die Berechnung der Skalarprodukte ganzer Modulformen

Commentarii Mathematici Helvetici (1949-12-01) 22: 168-199 , December 01, 1949

By Petersson, Hans

9 Citations

No abstract available

Über die komplexen Minimalflächen mit der Gaussschen Krümmung Null

Archiv der Mathematik (1949-07-01) 2: 283-288 , July 01, 1949

By Pinl, Max

3 Citations

No abstract available

Thermal expansion of fluorspar and iron pyrite

Proceedings of the Indian Academy of Sciences - Section A (1949-12-01) 30: 284-294 , December 01, 1949

By Press, D. C.

8 Citations

Summary

The paper describes the measurements of the thermal expansion of crystals of fluorspar and iron pyrite over the range of temperature from 40° C. to 300° C. by a modification of Fizeau’s interference method. In the case of flourspar, the linear coefficient of expansion has been found to increase steadily from 20·9 × 10⁻⁶ to 23·8 × 10⁻⁶ in the range from 40° C. to 260° C. while in the case of pyrite the linear coefficient increases from 9⊙7 × 10⁻⁶ to 11·5 × 10⁻⁶ in the same range. Using the measured values of the coefficents of thermal expansion and the known values of C_v, the Grüneisen constant γ has been evaluated for both the crystals. It is found that γ is not a constant but varies markedly with temperature.

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Dimensionstheorie der Polynomideale

Moderne Algebraische Geometrie (1949-01-01): 95-154 , January 01, 1949

By Gröbner, Wolfgang

Zusammenfassung

Es sei p ein beliebiges Primideal des P-Ringes K [x₁…, x_n], den wir kurz mit o bezeichnen. Der Restklassenring o/p ist ein Integritätsbereich (126.1), welcher den Zahlkörper K, oder genauer einen mit K isomorphen Körper umfaßt; dieser wird von allen denjenigen Restklassen mod p gebildet, welche ein Element aus K enthalten.² Den Quotientenkörper des Restklassenringes o/p nennen wir kurz den Restklassenhörper des Primideals p und bezeichnen ihn mit o_p.