Influence of layer and anisotropic fluctuations of the refractive index on the beyond-the-horizon SHF propagation in the troposphere over the sea when there is an evaporation duct

On the basis of the invariant imbedding method the disturbance theory for complex constants of propagation is proposed. This approach allows us to consider the influence of layer and anisotropic fluctuations of refractive index on the beyond-the-horizon propagation in the adiabatic approximation with the existence of an evaporation duct. Finally, the authors consider some examples of the calculations and investigate stochastic effects connected with the interaction between fluctuating and regular waveguides.     

Modification of magnetic anisotropy in metallic glasses using high-energy ion beam irradiation

Heavy ion irradiation in the electronic stopping power region induces macroscopic dimensional change in metallic glasses and introduces magnetic anisotropy in some magnetic materials. The present work is on the irradiation study of ferromagnetic metallic glasses, where both dimensional change and modification of magnetic anisotropy are expected. Magnetic anisotropy was measured using Mössbauer spectroscopy of virgin and irradiated Fe₄₀Ni₄₀B₂₀ and Fe₄₀Ni₃₈Mo₄B₁₈ metallic glass ribbons. 90 MeV ¹²⁷I beam was used for the irradiations. Irradiation doses were 5×10¹³ and 7.5×10¹³ ions/cm². The relative intensity ratios D ₂₃ of the second and third lines of the Mössbauer spectra were measured to determine the magnetic anisotropy. The virgin samples of both the materials display in-plane magnetic anisotropy, i.e., the spins are oriented parallel to the ribbon plane. Irradiation is found to cause reduction in magnetic anisotropy. Near-complete randomization of magnetic moments is observed at high irradiation doses. Correlation is found between the residual stresses introduced by ion irradiation and the change in magnetic anisotropy.     

The optical module of Baikal-GVD

In April 2015, the first cluster of Baikal-GVD was deployed in Lake Baikal and put into operation. It comprises eight strings. Each string consists of 24 optical modules. An optical module is a detection element of Baikal-GVD; it includes a Hamamatsu R7081-100 photomultiplier tube with a high quantum sensitivity. We describe the design of the optical module, the front-end electronics, and the laboratory characterization and calibration.     

Simplex optimization method for illumination design

A modified simplex optimization method is developed for the design of illumination systems. The simplex method is a judicious choice for illumination optimization because of its robustness and convergence properties. To optimize the simplex method, its four parameters are adjusted dependent on the dimensionality of the space to converge with fewer iterations. This work is presented for the end game, when the optimizer is converging on a local optimum rather than searching for it. Up to a 37% reduction in the number of computations is realized. An example using a compound parabolic concentrator is compared between the standard and the modified simplex methods, providing over 22% improvement in the end game.     

Synthesis of hydroxybiphenyls

Cyclohexylphenols were converted into hydroxybiphenyls via dehydration over large-scale palladium catalysts. The process involves slow reaction of the substrate with active centers of the catalyst with subsequent fast product formation and hydrogen desorption.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1337–1339.Original Russian Text Copyright © 2004 by Kuznetsova, Postnova, S. Koshel, Lebedeva, Yunkova, G. Koshel.     

Exact finite range CCBA results for the reaction 24Mg(d,p)25Mg at 14 and 15 MeV

The differential cross-sections for the ${}^{24}\text{Mg(d, p)}{}^{25}\text{Mg}\text{5}\text{2}{}^{\mathrm{+}}\text{(}\text{g.s.}\text{)}$ reactions at E_d = 15 Mev and $\text{7}\text{2}{}^{\mathrm{+}}\text{(1.61}\text{MeV state}\text{)}$ reaction at E_d = 14 and 15 MeV have been calculated using the full finite range CCBA code OUKID. It is shown that finite range effects are very important for these light ion reactions and that the deuteron D-state makes a negligible contribution at these energies.     

Parametric resonance with a point-vortex pair in a nonstationary deformation flow

The movement of a pair of point vortices with arbitrary intensities, embedded in a nonstationary shear and rotational flow, is studied. The expression for the vorticity center is shown to be reduced to a Riccati equation. In the particular case of harmonic oscillations, parametric resonance, which results in unbounded motion of the vortex pair, is found and analyzed. Using the fast oscillation averaging, an analytical estimate for the main zone in the parametric space is obtained. With the help of numerical calculations, the reliability of the estimate is asserted and a family of the minor zones is obtained.     

Composition and Properties of Aqueous Fluoroplastic Dispersion for Deposition of Metal–Polymer Coatings

Russian Journal of Applied Chemistry - Formulation of an aqueous dispersion of F-40 tetrafluoroethylene–ethylene copolymer for applying metal–polymer coatings by cathodic...     

Silicon nanocrystal synthesis by implantation of natural Si isotopes

Implantations of pure , , and into SiO₂ can provide significant insight into the formation of silicon nanocrystals (Si-nc) and their light emission properties. Si-nc produced with different fractions of the heavier Si isotopes have been characterized by Raman and photoluminescence spectroscopy. Weak Stokes shifts of the Si-nc phonon peaks indicate that both the implanted Si and the native Si from the SiO₂ substrate contribute to Si-nc nucleation. The Raman measurements also indicate that the Si isotopic composition of the Si-nc is similar to the Si isotopic fraction of the implanted SiO₂. The Si-nc photoluminescence (PL) spectra are shifted towards the blue with increasing Si isotope mass, an indication that the increase of the Si-nc effective mass enhances the excitonic bandgap. Measurements from samples implanted with heavy isotopes at high Si excess concentrations indicate that the Si-nc isotope fraction evolves with annealing time such that the heaviest Si isotope are more concentrated in the vicinity of the Si-nc/SiO₂ interface, which can modify the energy states involved in the radiative transitions associated with Si-nc.