Non-Landau damping of magnetic excitations in systems with localized and itinerant electrons

We discuss the form of the damping of magnetic excitations in a metal near a ferromagnetic instability. The paramagnon theory predicts that the damping term should have the form $\Omega/\Gamma (q)$ with $\Gamma (q) \propto q$ (the Landau damping). However, the experiments on uranium metallic compounds UGe$_2$ and UCoGe showed that $\Gamma (q)$ tends to a constant value at vanishing $q$. A non-zero $\Gamma (0)$ is impossible in systems with one type of carriers (either localized or itinerant) because it would violate the spin conservation. It has been conjectured recently that a non-zero $\Gamma (q)$ in UGe$_2$ and UCoGe may be due to the presence of both localized and itinerant electrons in these materials, with ferromagnetism involving predominantly localized spins. We present microscopic analysis of the damping of near-critical localized excitations due to interaction with itinerant carriers. We show explicitly how the presence of two types of electrons breaks the cancellation between the contributions to $\Gamma (0)$ from self-energy and vertex correction insertions into the spin polarization bubble and discuss the special role of the Aslamazov-Larkin processes. We show that $\Gamma (0)$ increases with $T$ both in the paramagnetic and ferromagnetic regions, but in-between it has a peak at $T_c$. We compare our theory with the available experimental data.Comment: 8 pages including Supplemental Material, version published in Phys. Rev. Let

Principles of Manufacturing of DC On-Board Harness for a Spacecraft Based on 3D Technology

This article describes in detail principles of manufacturing of DC on-board harness for spacecraft based on a new 3D design technology. This technology puts together all activities of on-board harness production, starting from electrical design and up to the final product readiness. Based on the analysis performed we proposed: necessary software, methods of wires and connector contacts connection, applicable wires and connectors available in Russian and European markets, shielding and insulating materials, test methods. The article discusses benefits of lightweight supply buses technology implementation (as compared to bundle of wires), which are: mass reduction, electrical performances stability improvement, lesser capacity between supply lines, better interference immunity, better thermal performances

Technology of 3D Simulation of High-Speed Damping Processes in the Hydraulic Brake Device

This chapter describes a three-dimensional simulation technology for physical processes in concentric hydraulic brakes with a throttling-groove partly filled hydraulic cylinder. The technology is based on the numerical solution of a system of Navier–Stokes equations. Free surface tracking is provided by the volume of fluid (VOF) method. Recoiling parts are simulated by means of moving transformable grids. Numerical solution of the equations is based on the finite-volume discretization on an unstructured grid. Our technology enables simulations of the whole working cycle of the hydraulic brake. Results of hydraulic brake simulations in the counter-recoil regime are reported. The results of the simulations are compared with experimental data obtained on JSC “KBP” test benches. The calculated and the experimental sets of data are compared based on the piston velocity as a function of distance. The performance of the hydraulic brake is studied as a function of the fluid mass and firing elevation of the gun

Non-analytic behavior of 2D itinerant ferromagnets

We consider an ordered ferromagnet in the vicinity of a T=0 transition into a paramagnet. We show that the free energy and the transverse and longitudinal static susceptibilities contain non-analyticities which destroy a continuous second-order transition. Depending on the parameters, the transition either becomes first-order, or occurs via an intermediate spiral phase.Comment: 4 pages, 3 figure

Nonanalytic behavior of two-dimensional itinerant ferromagnets

We consider an ordered ferromagnet in the vicinity of a T=0 transition into a paramagnet. We show that the free energy and the transverse and longitudinal static susceptibilities contain nonanalyticities which destroy a continuous second-order transition. Depending on the parameters, the transition either becomes first-order, or occurs via an intermediate spiral phase

LEGAL BASIS FOR THE DEVELOPMENT OF AN INDUSTRIAL INTERNET PLATFORM IN THE CONTEXT OF DIGITAL TRANSFORMATION

Objective: The purpose of this study is to analyze the experience of using industrial Internet platforms in China and its impact on the regulation of production services of enterprises. The study analyzes the concept of global value chains and examines the distribution of benefits among participating countries as a result of the deepening of the international division of labor.Methods: A combination of research methods, including factorial, comparative, and structural analysis, was used to achieve the research objectives. The main research material consisted of Russian and international statistical data, Russian and international legal frameworks, and comparative legal analysis.Results: Industrial Internet platforms not only promote cooperation between the production party and upstream and downstream enterprises in the value chain but also increase the added value of the production party and smoothen the smile curve.Conclusion: The article combines the concept of proactive artificial intelligence and suggests an innovative direction for the industrial Internet. The development of industrial Internet platforms plays a crucial role in the digital transformation of production processes. This requires a comprehensive legal and regulatory framework to ensure data confidentiality, intellectual property protection, and secure cross-border data transfer

Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons

We discuss the form of the damping of magnetic excitations in a metal near a ferromagnetic instability. The paramagnon theory predicts that the damping term should have the form γ(q,Ω)â̂ Ω/Γ(q), with Γ(q)â̂ q (the Landau damping). However, the experiments on uranium metallic compounds UGe2 and UCoGe showed that Γ(q) is essentially independent of q. A nonzero γ(q=0,Ω) is impossible in systems with one type of carrier (either localized or itinerant) because it would violate the spin conservation. It has been conjectured recently that a near-constant Γ(q) in UGe2 and UCoGe may be due to the presence of both localized and itinerant electrons in these materials, with ferromagnetism involving predominantly localized spins. We present the microscopic analysis of the damping of near-critical localized excitations due to interaction with itinerant carriers. We show explicitly how the presence of two types of electrons breaks the cancellation between the contributions to Γ(0) from the self-energy and vertex correction insertions into the spin polarization bubble. We compare our theory with the available experimental data. © 2014 American Physical Society

Principles of manufacturing of DC on-board harness for a spacecraft based on 3D technology

This article describes in detail principles of manufacturing of DC on-board harness for spacecraft based on a new 3D design technology. This technology puts together all activities of on-board harness production, starting from electrical design and up to the final product readiness. Based on the analysis performed we proposed: necessary software, methods of wires and connector contacts connection, applicable wires and connectors available in Russian and European markets, shielding and insulating materials, test methods. The article discusses benefits of lightweight supply buses technology implementation (as compared to bundle of wires), which are: mass reduction, electrical performances stability improvement, lesser capacity between supply lines, better interference immunity, better thermal performances