Bestimmung von Löschquerschnitten durch Lebensdauermessungen am Natrium-32 P-Zustand

The natural lifetime of the sodium resonance state has been measured using the phase-shift method. By addition of molecular gases the lifetime is shortened because of the nonradiative decay induced in collisions with molecules. The cross sections for such quenching collisions are obtained for various gases from an analysis of the dependence of the effective lifetime on the gas pressures.     

Beiträge zur Grenzflächenchemie der Polyorganosiloxane

Ohne ZusammenfassungWir danken den Herren Dr.Gölitz und Dr.de Montigny für ihre Hilfe bei der Präparierung der organofunktionellen Siloxane. Bei der Herstellung der übrigen Präparate und der Auswertung der Messungen unterstützte uns Frl.Edith Geselle.     

Zur Halbwertszeit des 1,49 MeV-Niveaus im Co57

For the halflife of the 1,49 MeV state in Co⁵⁷ an upper limit of 3,0 × 10^?10 sec. has been found.     

X-rays from antiprotonic helium in helium gas

X-ray transitions to the 4F, 3D, and 2P atomic levels of p?He have been observed with antiprotons stopped in He gas at 4 and 1.1 atm NT. The population by radiative transitions of the 3D level in gas Y_M(4atm) = (28±14)% and Y_M(1.1 atm) = (43±22)% exceeds by more than one order of magnitude that measured in liquid He. The annihilation width of the 3D level Γ^a_3D = 2.8±1.0 × 10^?3eV is determined from the ratio between the numbers of X-rays feeding and depopulating the 3D level. The strong-interaction shift of the 2P level ε(2P) = ?14±6 eV is obtained by inputting the $\text{p}\text{He}$ experimental X-ray yields into a cascade calculation, the results of which are in good agreement with well-established data from muonic, pionic, and kaonic helium.     

Trennung der Fraktion „Vorlauf” vom rohen Pfefferminzöl

The static parameters of a column for rectification of crude peppermint oil were established theoretically and experimentally by using a model mixture of cineole and menthole. The isobaric equilibrium diagram was studied atp=3999 N/m² (30 Torr).     

Considérations sur les gradients généralisés de G. Fichera et E. De Giorgi

Résumé Dans notre ? Cours de Varenna ? (15–25 Ao?t 1954) nous avons comparé les notions de dérivé et d'intégrant, eu particulier dans la théorie des fonctions de cellule. Parmi les exemples examinés figurent au chapitre IV les gradients généralisés deG. Fichera et d'E. De Giorgi. Dans la présente note nous établissons quelques résultats qui y étaient formulés seulement comme conjectures. à Mauro Picone pour son 70^mo anniversaire.     

Phosphorescence properties and kinetics of the lowest triplet state T1 of a series of pyrene derivatives as obtained by ODMR techniques

The experimental results of an ODMR investigation of the radiative and nonradiative properties of the lowest electronically excited triplet state T₁ of a series of pyrene derivatives are presented. The paper gives the highly resolved phosphorescence spectra of 1,2-benzopyrene, naphtho-(2′, 3′ ; 1,2)-pyrene, anthraceno-(2′, 3′; 1, 2)-pyrene, 1,2:6,7-dibenzo-pyrene, 1,2-benzonaphtho-(2′, 3′; 6, 7)-pyrene and 1,2; 4,5-dibenzo-pyrene along with vibrational analyses and — in part — symmetry assignments. The correlation know from the literature between triplet energies and the ZFS-parameter D is discussed in terms of character orders. Three of the molecules exhibit an unusual deactivation behaviour similar to that of 3,4-benzo-pyrene where the out-of-plane level is not the slowest level. Several possibilities to explain this unexpected behaviour are discussed.