Quantum Fluctuations in FexMn1 – xSi with Inclusion of the LDA + U + SO Calculations of the Electronic Structure

Physics of the Solid State - Quantum spin fluctuations are studied in chiral helicoidal FexMn1 – xSi ferromagnets on the basis of the direct calculations of the electronic...     

Boiling Water Reactor with a Combined Moderator for Utilization of Reactor Grade Plutonium

Physics of Atomic Nuclei - The article presents the concept of a channel-type reactor with a combined cooled moderator. The moderator consists of ceramic beryllium oxide and a liquid...     

A New Approach to Estimation of the Thermal Conductivity of Titanium Alloys

Crystallography Reports - The thermal conductivities of seven titanium alloys (VT1-0, VT18U, VT20, IMI834, Ti6242S, Ti6Al4V, and Ti6Al7Nb) have been measured. According to the data obtained, the...     

Two-Laser Thermal Lens Spectrometry with Signal Back-Synchronization

A two-laser dual-beam thermal lens spectrometer based on continuous-wave lasers, which implements the mode with signal back-synchronization, is developed with the aim to develop instrumentation for thermal lens spectrometry. This mode offers a potentially higher sensitivity of measurements in comparison with the lock-in mode of thermal lens measurements and variation of conditions depending on the measurement medium (solvent, or dispersed system, or solids). The wider possibilities of the back-synchronization mode in thermal lens spectrometry both for solving problems of chemical analysis and in some related fields are shown.     

Magnetic-field-induced displacive phase transition in IV–VI compounds

The present work calculates the structural phase transition temperature (T_c) in a system with interband electron-phonon interaction in a strong magnetic field, assuming the temperature dependence of the soft-mode frequency to be due to anharmonicities. The results of the calculation are compared with the experiment on Pb_1?xGe_xTe.     

Dipole relaxation in weak and strong fields

The process of dipole relaxation in a homogeneous dielectric is studied on the basis of a two-state dipole model. The external field is not assumed to be weak. Two types of applied electric fields are considered: a linearly increasing field, and a field which changes by steps. At the present time pulsed electric fields have found wide application in electron-ion technology.Translated from Izvestiya VUZ. Fizika, No. 1, pp. 95–100, January, 1972.     

Far infrared and millimetre dielectric response of incommensurate and ferroelectric K2SeO4

Dielectric response of K₂SeO₄ in the spectral region 5–460cm^–1 was determined using transmissivity and reflectivity measurements as a function of temperature between 80 and 300K. The spectral features above 20cm^–1 are interpreted using results of lattice vibrational analysis in three known commensurate phases. The low-frequency dielectric anomaly in the incommensurate phase can be roughly described by critical slowing-down of a Debye relaxation given rise to by the overdamped infrared active phason mode which softens at the incommensurate-commensurate transition.     

Solutions of the Vlasov equation in Lagrange coordinates

We show that the method of “finite-size” particles is a discrete model of the Vlasov equation but in a different (effective) interaction potential. We calculate the effective potential explicitly in the most interesting case of the Coulomb interaction. We find the equations of motion of particles of “finite size” for the Gaussian form factor. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 151, No. 1, pp. 138–148, April, 2007.     

Phase Transition in Vertex-Reinforced Random Walks on {\mathbb{Z}} with Non-linear Reinforcement

Vertex-reinforced random walk is a random process which visits a site with probability proportional to the weight w _k of the number k of previous visits. We show that if w _k ∼ k ^α, then there is a large time T ₀ such that after T ₀ the walk visits 2, 5, or ∞ sites when α < 1, = 1, or > 1, respectively. More general results are also proven.