Adsorption of Hydroxyethyl Cellulose Selenium Nanoparticles during Their Formation in Water

Two previously unknown phenomena were observed in studying the reduction of selenious acid with ascorbic acid in an aqueous hydroxyethyl cellulose solution: (1) formation of nanoparticles of amorphous Se⁰ with uniform particle size distribution and mean particle radius of 15 ± 4 nm and (2) adsorption of more than 3000 macromolecules on these nanoparticles with formation of spherical nanostructures.     

Structure of ketoenamine derivatives of 5,5-dimethyl-2,4-hexanedione

Conclusions The addition of amines to 5,5-dimethyl-2,4-hexanedione goes preferentially at the acetyl group as the less sterically hindered.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1795–1800, August, 1979.The authors express their gratitude to A. I. Kol't-sov for assistance in the interpretation of the PMR spectra.     

On the two approaches to the data analysis of the Cassini interplanetary relativity experiment

We compare two theoretical approaches to the data analysis of the Cassini relativity experiment based on the Doppler tracking and the time delay technique that were published correspondingly by Kopeikin et al. [S.M. Kopeikin, A.G. Polnarev, G. Schäfer, I.Yu. Vlasov, Phys. Lett. A 367 (2007) 276] and by Bertotti et al. [B. Bertotti, N. Ashby, L. Iess, Class. Quantum Grav. 25 (2008) 045013]. Bertotti et al. believed that they found a discrepancy with our paper and claimed that our analysis was erroneous. The present Letter elucidates, however, that the discrepancy is illusory and does not exist. The two techniques give the same result making it evident that the numerical value of the PPN parameter γ measured in the Cassini experiment is indeed affected by the orbital motion of the Sun around the barycenter of the solar system.     

Antineutrino background from spent-fuel storage in sensitive searches for θ 13 at reactors

Sensitive searches for antineutrino oscillations in the atmospheric mass-parameter region much discussed in recent years are based on accurate comparison of the inverse-beta-decay positron spectra measured in two (or more) detectors, far and near, stationed, e.g., at about 1000 and about 100 m from the reactor(s). We show that antineutrinos emitted from the stored irradiated fuel can distort in a different way the soft part of positron spectra measured in the far and near detectors and thus mimic (or hide) the oscillation signal. The text was submitted by the authors in English.     

Components of antineutrino emission in nuclear reactor

New ?_ee scattering experiments aimed at sensitive searches for the ν_e magnetic moment and projects to explore small mixing angle neutrino oscillations at reactors require a better understanding of the reactor antineutrino spectrum. Six components which contribute to the total ?_e spectrum generated in a nuclear reactor are considered. They are beta decays of the fission fragments of ²³⁵U, ²³⁹Pu, ²³⁸U, and ²⁴¹Pu and decays of beta emitters produced as a result of neutron capture in ²³⁸U and in accumulated fission fragments which perturb the spectrum. For antineutrino energies of less than 3.5 MeV and for each of the four fissile isotopes, the time evolution of ?_e spectra is given during fuel irradiation and after the irradiation is stopped. The relevant uncertainties are estimated. Small corrections to the ILL spectra are considered.     

Effect of noise on the relaxation to an invariant probability measure of nonhyperbolic chaotic attractors

We study the influence of external noise on the relaxation to an invariant probability measure for two types of nonhyperbolic chaotic attractors, a spiral (or coherent) and a noncoherent one. We find that for the coherent attractor the rate of mixing changes under the influence of noise, although the largest Lyapunov exponent remains almost unchanged. A mechanism of the noise influence on mixing is presented which is associated with the dynamics of the instantaneous phase of chaotic trajectories. This also explains why the noncoherent regime is robust against the presence of external noise.     

Neutrino geophysics at baksan: On searches for antineutrinos and radiogenic-heat sources in the interior of the earth

Antineutrinos produced in the Earth (geoneutrinos) carry information that is of crucial importance for the understanding of the origin and evolution of our planet. It is shown that the Baksan Neutrino Observatory of the Institute for Nuclear Research (Moscow, Russian Academy of Sciences) may become one of the best laboratories for studying geoneutrinos with the aid of a large scintillation spectrometer. The article also presents a brief history of the development of concepts of the Earth as a source of antineutrinos—it dates back to 1960, spanning a period of nearly 45 years (1960–2004).