Thermal equilibration between two quantum systems

Two identical finite quantum systems prepared initially at different temperatures, isolated from the environment, and subsequently brought into contact are demonstrated to relax towards Gibbs-like quasi-equilibrium states with a common temperature and small fluctuations around the time-averaged expectation values of generic observables. The temporal thermalization process proceeds via a chain of intermediate Gibbs-like states. We specify the conditions under which this scenario occurs and corroborate the quantum equilibration with two different models.Comment: 10 pages, 9 figures, including supplementary materia

Mathematical model of composite fibre-glass aramide-wired cord rheological properties

This paper describes the rheological properties of composite fibre-glass aramide-wired cords which, in its turn, are applied in large-sized structures for space systems. Based on experimental data a new mathematical model describing creeping and relaxation of composite cords is proposed. This model defines the operation time of the composite cords to be 15 years

Calculation method for cable-beam shell structures

This paper presents a calculation method suitable for cable-beam shell structures. It is based on both nonlinear finite element and force density methods. The main idea is to define the solution sequence for stress - strain state problem of above mentioned structures by nonlinear finite element method. Every successive solution involves the previous one as an initial estimate in convergent domain. To find an initial estimate for the first solution a force density method is used. The proposed method is tested on a new large space umbrella reflector

Disturbance impulse effects on large umbrella space reflector dynamics

Large umbrella space antennas are essential for communication, monitoring and observation of Earth and space objects. Despite investigations devoted to space antenna dynamics, the disturbance impulse shape effect on the root mean square error of spacecraft antenna reflecting surface has not been studied. This paper overcomes this gap describing disturbance impulse impact on root mean square error of spacecraftantenna reflecting surface relative to paraboloid via nonlinear finite element method. Based on numerical results root mean square dependency on disturbance time for rectangular and sine impulses was calculated. This approach could be applied in studying antenna reflecting surface response on disturbance impulse for different types of perspective large space antennas

Quantum machine using cold atoms

For a machine to be useful in practice, it preferably has to meet two requirements: namely, (i) to be able to perform work under a load and (ii) its operational regime should ideally not depend on the time at which the machine is switched-on. We devise a minimal setup, consisting of two atoms only, for an ac-driven quantum motor which fulfills both these conditions. Explicitly, the motor consists of two different interacting atoms placed into a ring-shaped periodic optical potential -- an optical "bracelet" --, resulting from the interference of two counter-propagating Laguerre-Gauss laser beams. This bracelet is additionally threaded by a pulsating magnetic flux. While the first atom plays a role of a quantum "carrier", the second serves as a quantum "starter", which sets off the "carrier" into a steady rotational motion. For fixed zero-momentum initial conditions the asymptotic carrier velocity saturates to a unique, nonzero value which becomes increasingly independent on the starting time with increasing "bracelet"-size. We identify the quantum mechanisms of rectification and demonstrate that our quantum motor is able to perform useful work.Comment: simplified notations, extended figure captions; 16 pages, 6 figure

DEVELOPMENT OF DIRECTIONS OF SCIENTIFIC RESEARCH IN PEDAGOGICAL UNIVERSITY OF WESTERN SIBERIA IN THE 1930s

Цель. Статья посвящена актуальной в условиях современной политико-экономической реальности теме истории педагогики. Предметом анализа выступает процесс развития научных направлений в педагогических исследованиях, связанных с политическими и экономическими реформами в период первых пятилеток в Новосибирской, Омской, Томской, Тюменской, Барнаульской областях. Автор ставит целью охарактеризовать направления научно-педагогических исследований, проводимых в 1930-х гг. в педагогических вузах Западной Сибири.Метод или методология проведения работы. Основу исследования образует контент-анализ архивных документов, а также историографический, ретроспективный, сравнительно-сопоставительный, хронологический методы, детерминированные факторами исторического развития общества, что позволяет сформировать более объективный взгляд на рассматриваемую проблему.Результаты. Результаты работы заключаются в том, что автор показывает аргументы и преемственность развития научно-педагогических исследований, проводимых в педагогических вузах Западной Сибири. Результаты исследования могут расширить представления о данном историческом периоде развития нашей страны, позволят глубже понять не только эволюционную преемственность современных подходов в организации педагогического образования, но и историческую значимость деятельности системы педагогического образования в целом.Область применения результатов. Выводы могут быть применены в сфере социально-педагогического проектирования и прогнозирования в процессе модернизации педагогического образования в современных условиях.Purpose. The article is devoted to the subject of the history of pedagogy, which is topical in the current political and economic reality. The subject of the analysis is the process of development of scientific directions in pedagogical studies related to political and economic reforms during the first five-year plans in the Novosibirsk, Omsk, Tomsk, Tyumen, Barnaul regions. The author aims to characterize the directions of scientific and pedagogical research conducted in the 1930s. in pedagogical universities of Western Siberia.Methodology. The basis of the research is the content analysis of archival documents, as well as historiographic, retrospective, comparative-comparative, chronological methods determined by factors of the historical development of society, which allows to form a more objective view of the problem under consideration.Results. The results of the work consist in the fact that the author shows the arguments and continuity of the development of scientific and pedagogical research conducted in the pedagogical universities of Western Siberia. The results of the research can broaden the understanding of this historical period of our country’s development, will allow us to understand more deeply not only the evolutionary continuity of modern approaches in the organization of pedagogical education, but also the historical significance of the activity of the system of pedagogical education as a whole.Practical implications. Conclusions can be applied in the field of socio-pedagogical design and forecasting in the process of modernization of pedagogical education in modern conditions

Thermomechanical analysis of large deployable space reflector antenna

In this article results of large reflector thermal condition forecast using modern numerical simulation methods are presented. The results of thermal analysis are complemented with stress-strain analysis results of the whole structure under thermal loads

The applicability of acoustic emission method to modeling the endurance of metallic construction elements

Acoustic emission method is the most effective nondestructive inspection technique of construction elements. This paper considers the expanded applicability of acoustic emission method to modeling the damage and the remaining operational life of building structures, including the high-ductile metals. The modeling of damage accumulation was carried out to predict endurance using acoustic emission method