Magnetic isotope effect in the photochemical reduction of uranyl nitrate

A magnetic isotope effect was found in the photochemical reduction of uranyl nitrate by p-methoxyphenol. The initial²³⁸U/²³⁵U ratio equal to 8.93±0.008 was altered during the reaction to 8.945±0.008-8.970±0.005 in the reaction product, namely, uranium tetrafluoride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1902–1903, August, 1990.     

Matrix hodoscopes for the Oka (Protvino) and NA62 (SPS,CERN) experimental setups

The matrix hodoscope of the OKA experimental setup and a prototype of the hodoscope for the NA62 experiment are described. The design of both hodoscopes is presented. The requirements for the hodoscope prototype are listed, and the efficiency and the time resolution obtained on the basis of experimental data are quoted.     

Effect of nickel on the magnetic state of dysprosium in Dy<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Ni<Subscript>x</Subscript>-Ni bilayer films

This paper reports on the results of investigations into the temperature and spectral dependences of the magnetic circular dichroism in Dy_1?xNi_x-Ni bilayer films prepared through thermal sputter deposition of components under ultrahigh vacuum. The distribution of the components over the layer thickness is examined by Auger spectroscopy. The nickel content x in Dy_1?xNi_x layers varies from 0.005 to 0.06. It is shown that, in the temperature range 80–300 K, the contribution made to the magnetic circular dichroism by a Dy_1?xNi_x layer in a bilayer film with a nickel content higher than the threshold value is approximately equal to the magnetic circular dichroism observed in an isolated Dy_1?xNi_x film at temperatures below the temperature of the phase transition to a ferromagnetic state (～100 K). This phenomenon is explained by magnetic ordering in the Dy_1?xNi_x layer of the bilayer film due to the combined effect of two factors, namely, the incorporation of nickel into a dysprosium layer and the presence of a continuous nickel sublayer in the film.     

Femtosecond dynamics of relaxation of photoexcited meso-tetraferrocenylporphyrin in the nonprotonated and diprotonated forms (Fc4PH2 and Fc4PH42+)

The relaxation of the Q¹(—*) excited state of the nonprotonated Fc₄PH₂ and diprotonated Fc₄PH₄ ²⁺ forms of meso-tetraferrocenylporphyrin was studied by femtosecond laser absorption spectroscopy. Transition from the Q¹(—*) state to the charge-transfer state was shown to occur within 208±10 fs for Fc₄PH₂ and 9±3 ps for Fc₄PH₄ ²⁺. A fast vibrational relaxation with a characteristic time of 120—140 fs was found for both forms. The relaxation time of Fc⁺—P^– charge-transfer state for Fc₄PH₂ was 17±4 ps.