Vol 193, No 6 (2023)

The breakdown of gauge symmetry within Grand Unified Theories (GUTs) can result in supersymmetric (SUSY) extensions of the Standard Model (SM) at low energies, which allows the electroweak scale to be almost stabilized. The gauge coupling unification, Higgs sector, and restrictions on the sparticle spectrum are considered in the framework of several SUSY extensions of the SM. Possible manifestations of these SUSY models and existing experimental limits are also discussed.

Investigations carried out in recent years on the development of models and computer programs for predicting and analyzing the physical properties of polymers are described. The method for constructing diagrams of compatibility of water permeability and the glass transition temperature, density, the thermal expansion coefficient, the cohesion energy, etc. is analyzed. Computer synthesis of network polymers and the possibility of predicting the thermal expansion coefficient of materials based on polyvinyl chloride and the elastic modulus of composites with a number of aromatic polymers are considered. The effect of a solvent (plasticizer) on strength and viscosity is analyzed. Considerable attention is paid to the use of self-oscillations excited during deformation of polymer films in actuators of nanomechanical devices. The calculation of the viscosity of dispersions of spherical nanoparticles with an adsorption polymer layer in a polymer melt and in a low-molecular liquid is carried out. The principles of predicting the coefficients of molecular packing of amorphous-crystalline polymers and their solvents are stated, and the influence of the chemical structure of heat-resistant thermoplastics on friction against steel is also estimated.

Very high accuracy and sensitivity have become attainable by modern instruments for experimental measurements of physical quantities in various scientific fields. Yet it is still impossible to completely eliminate the influence of instrumental effects on the result. The measured values of a physical quantity inevitably differ, sometimes significantly, from the true ones. The question therefore arises of restoring the true distributions from the measured ones, taking the specific features of the experiment and the characteristics of scientific instruments into account. Different approaches are in use based on a mathematical model of the instrument and the formulation of the deconvolution problem. We describe this problem, key ideas and methods for its solution, and features and implementation details using the example of elementary particle physics and space physics experiments.