Spectroscopic characteristics of new F 2+‐like centers in LiF‐Mg, OH crystals are studied. The role of the divalent Mg impurity in the formation of F 2+ centers in LiF is revealed. By comparison of measured and calculated energy parameters a tentative model and a mechanism for the formation of the centers studied are suggested.
The subject of the research is to study the impact of modern digital technologies on the organization and management of public utilities within the framework of the concept of “smart HCS”, which ensures optimization of municipal budgets, reducing the costs of homeowners for the maintenance of real estate, and, as a result, improving the quality of life of citizens. The purpose of the study is to identify promising areas of digitalization of the housing and communal services sector (hereinafter referred to as HCS), creating comfortable and safe living conditions for citizens using smart technologies adapted to the “smart city” concept. In the course of the study, the methods of scientific analysis were used, including methods of analogies for generalization and comparative analysis of the digitalization of such areas as the “smart” housing sector and the “smart” utility sector. The result of the study is to highlight the most promising areas of digital transformation of the public utilities sector and the positive effect that can be obtained for each participant in this business process. As a conclusion, it should be noted that the active implementation of the concept of “smart HCS” will help in solving such problems as increasing the readiness of management companies and resource supplying organizations to use digital technologies for high-quality provision of public services to the population, intensifying work on the formation of a unified information environment for control and supervision in the field of HCS through the further development of SIS HCS, etc.
Показаны задачи Программы «Цифровая экономика Российской Федерации» в развитии информационной и инновационной инфраструктуры. Рассмотрены факторы, определяющие динамику инновационного развития российской экономики. Дан анализ современного состояния ГСНТИ и сформулированы наиболее актуальные и перспективные направления её модернизации. Представлена макроструктура комплекса работ и мероприятий по модернизации системы информационного обеспечения научно-промышленной сферы, факторы, обеспечивающие становление и развитие Национальной информационной системы, и направления разработки и реализации новой научно-информационной политики развития ВИНИТИ РАН. Констатируется, что масштабная задача воссоздания современной отечественной информационной инфраструктуры носит междисциплинарный и надведомственный характер.
In the presented article we propose a mathematical model for nonlinear response of the polycristalline ferroelectrics, an efficient numerical algorithm for its parameters identification, and finally we deal with the ways of their using in practice. Piezoelectrics and ferroelectrics constitute an important class of materials known owing theirs wide application as sensors and actuators in a large number of devices and components. The control, description, and understanding of piezoelectrics and ferroelectrics behavior present thus an important and difficult undertaking from both the practical and theoretical point of view. The piezoelectric hysteresis is an important property of piezoelectric and ferroelectric materials caused by different physical processes that take place in ferroelectric materials, e.g. domain-wall pinning, defect ordering, etc. Most often hysteresis is undesired in high-precision sensor, actuator and capacitor applications. But leaving out of framework the origin and mechanisms of the piezoelectric hysteresis the necessity of devices rational design forces to develop the specialized CAE systems to be able to simulate and optimize an efficiency of the ferroelectric-based devices, considering both useful and undesirable phenomena. So, finite-element modeling of sensor and actuator devices requires knowledge of the supplementary constitutive relations that are valid at broad range of electric fields, including the cases of irreversible polarization or depolarization process. There are several approaches to deriving the governing relationships, particularly, orientation Jiles–Atherton model, where governing relationships are formulated by increments between some intrinsic and target parameters. At low mathematical complexity this model is based on the transparent physical meanings, allowing to describe the work of electric field rotating the domains, and energy destructing the fixed domain walls. The proposed model represents a nonlinear ordinary differential equation relative to polarization and driving by electric field. Together with incremental theory this model allows to describe the real behavior of the physical object and to determine all needed field features at list for quasistatic process. As many models describing a nonlinear behavior of whole class of polycristalline materials our model depends on the five intrinsic parameters which have a different physical nature, and have influence on the nonlinear hysteretic response of material. Settings of model imply an unambiguous determination of such parameters. Identification of these parameters is a coefficient inverse problem, and for its resolving we have used the experimentally obtained hysteretic loops. At numerical implementation the set of these five parameters minimize a discrepancy functional square depended on experimentally observed and calculated points of hysteretic loop. Due to complexity of the minimized functional behavior on the space of identified parameters the minimization procedure was realized by means of Genetic Algorithm Toolbox MATLAB. The developed numerical method for hysteresis differential operator parameters identification has shown the good efficiency, robustness, and speedy convergence. These parameters then have used for static and modal analysis by finite element package ACELAN that utilizes an incremental theory for describing of irreversible polarization process. Finally we demonstrate some calculation results for non-uniformly polarized piezoceramic elements.
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