Bulletin of the Russian Academy of Sciences: Physics最新文献

As a part of the first-stage experimental stations at the SKIF Center for Shared Use, a unique station 1–3 “Fast Processes” is being created, designed to study detonation, shock wave processes, as well as processes of reaction of materials to pulsed thermal or mechanical influence. The station will include three sections: the “Plasma” section, designed to study the processes of reaction of materials to pulsed thermal and mechanical loads; section “Dynamic processes, main building”, which is supposed to study shock wave processes and section “Dynamic processes, separate building”, intended for studying detonation and shock wave processes. To conduct experiments at stations 1–3, five coordinate X-ray detectors of various types are being developed. We described in detail the characteristics of the detectors and the status of development.

We studied the magnetic properties of Co₇₃Fe₄Si₁₂B₁₁ ferromagnetic microwires in initial amorphous and crystalline state achieved by thermal treatment with direct current. A microwire in amorphous state is found to be characterized with quasilinear hysteresis loop with small coercive force less than 0.05 kA/m. Once crystallized, the microwire loses its soft magnetic properties, its hysteresis loop radically expands, and the coercive force becomes equal to 15 kA/m.

The authors study diffractive optical elements manufactured via contact printing on a dichromated gelatin and direct laser writing on photoresist. The elements modify the point-spread function for three-dimensional super resolution fluorescence microscopy. It is shown that both elements produce two-lobed rotating light fields that can be used for three-dimensional nanoscopy. Results from the subdiffractive localization of fluorescent labels are presented, and the accuracy of coordinate reconstruction is determined.

Differential scanning calorimetry (DSC) is used to study the phase transformations of four amorphous metal alloys based on transition metals Fe and Ni with additives of Si and C. The temperature dependences of the heat flux upon phase transformations are measured along with changes in the mass and specific heat capacity of amorphous alloys. Two phase transformations associated with the temperature of glass transition and complete crystallization are identified. The relative volume of the crystalline fraction of alloys heated to 1000°C is calculated. It is concluded there are nanocrystalline phases between the first and second phase transitions at heating rates of 0.1°C/s.

Confocal optical microscopy data with a resolution of 1 μm on the spatial heterogeneity of a vitrified film prepared from a melt powder of an anisometric europium(III) β-diketonate complex are presented. It has been shown that the heterogeneity caused by crystalline inclusions in the amorphous structure of the film, leads to a temperature memory effect, when the film can be in different states at the same temperature.

The author considers three types of resonance of a classical coherent electromagnetic wave with the same carrier frequency as a quantum anharmonic oscillator, based on algebraic perturbation theory. The corresponding effective operators of the dipole moment of the anharmonic oscillator are obtained, allowing the polarization of the excited medium under the considered resonance conditions to be calculated. Some possibilities are established for the creation of nonlinear effects.

A study is performed of the magneto-optical Faraday effect of magnetic fluids based on MFe₂O₄ particles (M = Fe, Ni, Co) in which sodium oleate is used as dense surfactant. This allows Faraday rotation to be obtained at a low volume concentrations of these particles (0.25–0.5%). Rotation depends linearly on the strength of the magnetic field (500–1000 G), which is unsaturated up to 4000 G. The maximum effect is achieved for magnetic fluids based on CoFe₂O₄.

A methodology and a system are developed for complex remote diagnostics of insulation elements of high-voltage equipment of substations and power transmission lines, including suspended and through-pass insulators and supports. The system is based on the principle of simultaneously measuring and subsequently analyzing characteristics of partial discharges with high-frequency (400–800 MHz) and acoustic (30 kHz) sensors. The system is used to examine more than 50 specimens of polymer (LC 70/35) and porcelain (IOS 110/400) insulators in their operating mode. Amplitude-phase diagrams of partial discharge parameters are obtained that can be used to determine the type and degree of influence a defect has on the insulation. Features of defects are studied for 35 and 110 kV electrical networks.

Permalloy rod-shaped anisotropic nanoparticles have been used to study orientational relaxation in a polymethylsiloxane magnetic fluid. A magneto-rheological effect has been observed at different magnitudes and frequencies of the impact of a magnetic field, and the time of structural relaxation after removal of the field has been estimated.

The authors investigate the possibility of controlling the parameters of random number sequences using a continuous wavelet transform. It is shown that changing the energy of the scales of the continuous wavelet transform can increase the probability of passing the NIST LongestRun, FFT, and Runs tests. The possibility of increasing the probability of passing tests is demonstrated for different sizes of the studied experimental sequence of random numbers.