The earliest reckoning books existing in the Persian language

Two reckoning books edited recently in Teheran help to form an image of the hitherto almost unknown astronomer and mathematician Ab$\text{u}$ Ja'far Muh. b. Ayy$\text{u}$b $\text{T}\text{?}$abar$\text{i}$ who lived in $\text{A}$mul near the Caspian during the Saljuq period and observed from 1068 to 1092 A.D. The first of the said books is a textbook of Hindi reckoning similar to al-Nasaw$\text{i}$'s reckoning book (1029); the second one teaches mental calculation and application of both methods to everyday problems, much in the line of Ab$\text{u}$ al-Waf$\text{a}$'s reckoning book (c. 980 A.D.). Both texts are on a rather elementary level and include some errors, but they reveal their author as a skilled teacher and expound some interesting problems not found elsewhere. Moreover, they deserve our attention as the most ancient existing arithmetic treatises in the Persian language known so far.     

Über Defektbegriffe in der Theorie der meromorphen Funktionen

Ohne Zusammenfassung     

Die Sublimation und thermische Zersetzung von TeJ4 und die Existenz von TeJ2 in der Gasphase

The Sublimation and the Thermal Decomposition of TeJ₄ and the Existence of TeJ₂ in the Gaseous Phase The sublimation and the decomposition of TeJ₄ have been investigated. For the sublimation and the decomposition reactions and the values of enthalpy and entropy were derived (see ?Inhaltsübersicht”?). The existence of TeJ₂ in the gaseous phase was demonstrated by equilibrium measurements and chemical transport experiments.     

Fluoreszenz von 4,4′-disubstituierten 1,3-Diphenyl-2pyrazolinen mit Donator-Akzeptor-Substituen

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Experimental determination of electron distribution functions in degenerate GaAs at high electric fields

The change of the optical absorption due to applied electric fields up to 450 V/cm was measured on n-type GaAs having a carrier concentration of 10¹⁸ cm^?3 at 77 K. The fundamental absorption in degenerate n-type semiconductors is proportional to the number of unoccupied places in the conduction band at an energy, which is determined by the phonon energy and the bandstructure. Hence, the measured change in absorption allows the evaluation of the distribution function. Results are given as a function of the energy above the conduction band edge, which was determined assuming parabolic bands.     

Zerfällung topologischer Gruppen

Ohne Zusammenfassung