Autoresonant excitation of Bose-Einstein condensates

Controlling the state of a Bose-Einstein condensate driven by a chirped frequency perturbation in a one-dimensional anharmonic trapping potential is discussed. By identifying four characteristic time scales in this chirped-driven problem, three dimensionless parameters $P_{1,2,3}$ are defined describing the driving strength, the anharmonicity of the trapping potential, and the strength of the particles interaction, respectively. As the driving frequency passes the linear resonance in the problem, and depending on the location in the $P_{1,2,3}$ parameter space, the system may exhibit two very different evolutions, i.e. the quantum energy ladder climbing (LC) and the classical autoresonance (AR). These regimes are analysed both in theory and simulations with the emphasis on the effect of the interaction parameter $P_{3}$. In particular, the transition thresholds on the driving parameter $P_{1}$ and their width in $P_{1}$ in both the AR and LC regimes are discussed. Different driving protocols are also illustrated, showing efficient control of excitation and de-excitation of the condensate

Resonant control of solitons

It is shown that the effect of "scattering on resonance" can be used to control envelope solitons in the driven nonlinear Schrödinger equation. The control occurs by the frequency modulated driving with multiple crossing of the resonant frequency of the soliton. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved

Dag Hammarskjold and concept formation of peacemaking operations

© Medwell Journals, 2015. Actuality of the problem to be investigated depends on the circumstances that the armed conflicts have become widespread in the modern world. To settle up them the UNO carries out the peacemaking operations and the study of the process of formatting the peacemaking operation concept provides today an optimal policy of its fulfillment. The study aims at investigating the formation process of the concept of the peacemaking operations and the role of the Secretary General of the United Nations D. Hammarskjold there. The study deals with the formation process of the concept of peacemaking operations major contribution to which was made by the second UN Secretary General Dag Hammarskjold who was holding the post in the period of the years 1953-1961. The researcher considers, the attempts of forming international armed forces for the response to threatening to international peace and security. By way of the example of settlement of the conflicts in the Middle-East and the Congo the basic principles of peacemaking concept of Hammarskjöld are stated. The materials of the study may be useful in the process of discussion of a possible concept reformation of peacemaking operations of the UNO

Research of the thorium purification at monazite refinement processes

This paper is aimed to the research of the thorium purification processes at monazite refinement processes. We have investigated different solution containing thorium with different mix of rare-earth elements. It was found that the application of cation resin is well- recommended if we want to reach the highest yields of thorium purification process

Phase equilibrium liquid-vapor in three-component system UF6-IF5-BrF3 at complete mutual components solubility

The results of studying phase equilibrium liquid-vapor at 353,15 K in the system of uranium hexafluoride, iodine pentafluoride, bromine trifluoride have been presented. The dependences of saturated vapor pressure on condensed phase composition, the results of analysis of studied system deviation from error-free behavior, the data on equilibrium vapor phase are give

Anomalous autoresonance threshold for chirped-driven Korteweg-de-Vries waves

Large amplitude traveling waves of the Korteweg-de-Vries (KdV) equation can be excited and controlled by a chirped frequency driving perturbation. The process involves capturing the wave into autoresonance (a continuous nonlinear synchronization) with the drive by passage through the linear resonance in the problem. The transition to autoresonance has a sharp threshold on the driving amplitude. In all previously studied autoresonant problems the threshold was found via a weakly nonlinear theory and scaled as α3/4,α being the driving frequency chirp rate. It is shown that this scaling is violated in a long wavelength KdV limit because of the increased role of the nonlinearity in the problem. A fully nonlinear theory describing the phenomenon and applicable to all wavelengths is developed. © 2015 American Physical Society

Dynamics of Solitons and Quasisolitons of Cubic Third-Order Nonlinear Schr\"odinger Equation

The dynamics of soliton and quasisoliton solutions of cubic third order nonlinear Schr\"{o}dinger equation is studied. The regular solitons exist due to a balance between the nonlinear terms and (linear) third order dispersion; they are not important at small $\alpha_3$ ($\alpha_3$ is the coefficient in the third derivative term) and vanish at $\alpha_3 \to 0$. The most essential, at small $\alpha_3$, is a quasisoliton emitting resonant radiation (resonantly radiating soliton). Its relationship with the other (steady) quasisoliton, called embedded soliton, is studied analytically and in numerical experiments. It is demonstrated that the resonantly radiating solitons emerge in the course of nonlinear evolution, which shows their physical significance

Autoresonance in a Dissipative System

We study the autoresonant solution of Duffing's equation in the presence of dissipation. This solution is proved to be an attracting set. We evaluate the maximal amplitude of the autoresonant solution and the time of transition from autoresonant growth of the amplitude to the mode of fast oscillations. Analytical results are illustrated by numerical simulations.Comment: 22 pages, 3 figure

РИФЕЙСКИЙ МАГМАТИЗМ, ПРЕДШЕСТВУЮЩИЙ РАСКРЫТИЮ УРАЛЬСКОГО ПАЛЕООКЕАНА: ГЕОХИМИЯ, ИЗОТОПИЯ, ВОЗРАСТ, ГЕОДИНАМИЧЕСКИЕ СЛЕДСТВИЯ

The rocks from different stages of the geodynamic evolution have been preserved in the Urals. In its geologic history, the least studied is the transition period between continental rifting and the beginning of oceanic spreading. This article presents the geochemical data on the Sr-, Nd-isotopes, zircon U-Pb (SHRIMP) ages for the MesoNeoproterozoic igneous rocks and associated ores from the Bashkir meganticlinorium (BMA) on the Urals western slope. A Large Igneous Province (LIP) formed there as a result of mantle plume activity during the Middle Riphean (1380–1350 Ma). Later on (1200–1100 Ma), short-term rifting took place, as evidenced by the Nazyam graben, which was followed by the complete break-up of the continental crust. For magmatic rocks in the age range of 1750–1200 Ma, the evolition of chemical composition OIB-type → E-MORB →N-MORB is observed. The εNd(t) values for the igneous rocks and the associated BMA ores vary from negative (–6) to positive ones (+5), and thus give evidence of the lithosphere mantle depletion with time. These facts and the Sr-isotope ratios for the magmatic rocks from the subsequent evolution stages confirm that the oceanic basin to the east of the East European platform started to open at the end of the Middle Riphean. For the Vendian-Cambrian, some traces of orogenes (Timanian stage) are observed. The development of the Uralian Paleozoic ocean started in the Ordovican and continued up to the Late CarboniferousPermian.Урал – одна из немногих структур, в которой сохранились породы всех стадий геодинамической эволюции. Наименее изученным в его геологической истории является период, переходный от континентального рифтинга к океаническому спредингу. В статье представлены новые данные по геохимии, изотопии Sr и Nd, U-Pb (SHRIMP) возрасту цирконов магматических пород и связанных с ними руд Башкирского мегантиклинория (западный склон Южного Урала), имеющих мезонеопротерозойский возраст. В среднем рифее (1380–1350 млн лет) здесь была сформирована крупная изверженная провинция (LIP) как возможный результат активности мантийного плюма. Затем (около 1100 млн лет) имел место полный разрыв континентальной коры, и краткое время существовала рифтовая структура (Назямский грабен). Для магматических пород с возрастом 1750–1100 млн лет фиксируется геохимическая эволюция составов: OIB →E-MORB→ N-MORB. При этом εNd изменяется от отрицательных (–6) до положительных значений (+5), указывая на обеднение литосферной мантии со временем. Эти факты, наряду с поведением изотопов Sr для пород всех последующих стадий эволюции Урала, указывают на то, что океаническое пространство к востоку от Восточно-Европейской платформы открылось в конце среднего рифея. В венде – кембрии присутствуют признаки орогенных событий (Тиманский этап). С ордовика началось развитие Уральского палеозойского океана, существовавшего до верхнего карбона – ранней перми

Определение фоновых изотопных отношений биодоступного стронция для рудника бронзового века новотемирский

To assess the mobility and provenance of ancient populations, it is necessary to compare their 87Sr/86Sr isotopic ratios with the local bioavailable strontium baseline (background), characteristic of each specific location or potential provenance region of an individual or artifact. Its definition requires a comprehensive approach to the analysis of heterogeneous samples («proxies») characterizing the ecosystem of the archaeological site under study, the identification of the most suitable proxies, as well as the unification and standardization of the sampling and analytic protocols. A pilot study is presented devoted the definition of the local range of bioavailable strontium by the example of the Novotemirskiy Bronze Age mine (Southern Urals). 87Sr/86Sr isotope ratios were determined in surface and underground water, bedrock (serpentinite), clay from the mine wall, and steppe polecat’s bone, as well as in grass and a bivalve shell from the lake. The lowest range of strontium isotope ratios relative to each other is characteristic of surface and groundwater, shell and grass, which allows them to be used to determine the combined baseline of bioavailable strontium. Multi-proxy (surface and underground water, grass and a bivalve shell) local bioavailable strontium baseline for the Novotemirskiy ancient mine (Southern Urals) is 0,7096 ± 0,0003 (2σ, n = 5). © 2021 Russian Academy of Sciences, Institute of Archaeology. All rights reserved.Работа выполнена при финансовой поддержке РНФ, проект No 20-18-00402 «Миграции человеческих коллективов и индивидуальная мобильность в рамках мультидисциплинарного анализа археологической информации (бронзовый век Южного Урала)», в ЮУрГУ (НИУ) (Д. В. Киселева – геохимическая интерпретация, П. С. Анкушева – археологическая документация и аналитика; Т. Г. Окунева, А. В. Касьянова – измерения проб и стандартных образцов; Е. С. Шагалов, М. Н. Анкушев – отбор проб и геологическая характеристика)