Wave packet dynamics in hole Luttinger systems

For hole systems with an effective spin 3/2 we analyzed analytically and numerically the evolution of wave packets with the different initial polarizations. The dynamics of such systems is determined by the $4\times 4$ Luttinger Hamiltonian. We work in the space of arbitrary superposition of light- and heavy-hole states of the "one-particle system". For 2D packets we obtained the analytical solution for the components of wave function and analyzed the space-time dependence of probability densities as well as angular momentum densities. Depending on the value of the parameter $a=k_0d$ ($k_0$ is the average momentum vector and $d$ is the packet width) two scenarios of evolution are realized. For $a>>1$ the initial wave packet splits into two parts and the coordinates of packet center experience the transient oscillations or {\it Zitterbewegung} (ZB) as for other two-band systems. In the case when $a0$ remains almost cylindrically symmetric and the ripples arise at the circumference of wave packet. The ZB in this case is absent. We evaluated and visualized for different values of parameter $a$ the space-time dependence of angular momentum densities, which have the multipole structure. It was shown that the average momentum components can precess in the absence of external or effective magnetic fields due to the interference of the light- and heavy hole states. For localized initial states this precession has a transient character.Comment: 9 pages, 8 gigur

Graphene superlattice with periodically modulated Dirac gap

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under certain conditions. As a result, the gap between conduction and valence minibands disappears. The expressions for the position of these Dirac points in ${\bf k}$-space and threshold value of the potential for their emergence were obtained. At some parameters of the system, we have revealed interface states which form the top of the valence miniband.Comment: 5 pages, 4 figures, accepted to Physical Review

The long-term cyclotron dynamics of relativistic wave packets: spontaneous collapse and revival

In this work we study the effects of collapse and revival as well as {\it Zitterbewegung} (ZB) phenomenon, for the relativistic electron wave packets, which are a superposition of the states with quantum numbers sharply peaked around some level $n_0$ of the order of few tens. The probability densities as well as average velocities of the packet center and the average spin components were calculated analytically and visualized. Our computations demonstrate that due to dephasing of the states for times larger than the cyclotron period the initial wave packet (which includes the states with the positive energy only) loses the spatial localization so that the evolution can no longer be described classically. However, at the half-revival time $t=T_R/2$ its reshaping takes place firstly. The behavior of the wave packet containing the states of both energy bands (with $E_n>0$ and $E_n<0$) is more complicated. At short times of a few classical periods such packet splits into two parts which rotate with cyclotron frequency in the opposite directions and meet each other every one-half of the cyclotron period. At these moments their wave functions have significant overlap that leads to ZB. At the time of fractional revival each of two sub-packets is decomposed into few packets-fractions. However, at $t=T_R$ each of the two sub-packets (with positive or negative energy) restores at various points of the cyclotron orbit, that makes it impossible reshaping of initial wave packet entirely unlike the wave packet which consists of states with energies $E_n>0$ only. Obtained results can be useful for the description of electromagnetic radiation and absorption in relativistic plasma on astrophysics objects, where super high magnetic field has the value of the order $10^8-10^9$T, as well as for interpretation of experiments with trapped ions

Methodological bases for assessing socio-demographic and migration consequences of man-made disasters

The purpose of the research is to develop methodological bases and principles for assessing the socio-demographic (including migration) consequences of man-made disasters. A method of rapid assessment of possible outgoing migration flows that may occur in the event of a man-made emergency of various scales is proposed. The initial data for this method are quantitative statistical register data on housing stock and population, as well as operational data on the scale of destruction obtained using contactless methods of information collection. The author summarizes the legal acts regulating the work on prevention and elimination of consequences of man-made and other emergencies in Russia, as well as establishing the principles for assessing their consequences. The author proposes a rearrangement of the set of consequences of man-made disasters, including three main directions of the impact of emergency situations on various spheres: demographic (including damage to life and health, as well as the migration component), socio-economic, and natural and environmental. Indicators reflecting the consequences of the disaster have been developed for each of th

The Simulated Experimental Design and Study of the Synergistic Treatment of Chicken Manure and Traditional Chinese Medicine Residues on Earthworm Growth and Soil Quality

Annelids conspicuously exert influence upon soil physicochemical attributes through their alimentary, burrowing, and excretion endeavors, thereby imparting ramifications upon soil erosion phenomena. Nevertheless, comprehension of the particular repercussions stemming from annelid activities vis-à-vis soil erosion remains circumscribed. The primary objective of this investigation was to scrutinize the synergistic ramifications of gallinaceous fecal matter and remnants of traditional Chinese medicinal substances on annelid proliferation and soil characteristics within a simulated experiment. In order to gauge the impact of annelid activities upon soil hydric distribution, runoff velocity, and soil erosion, a laboratory-simulated precipitation experiment was executed across three incline gradients (5 degrees, 10 degrees, and 15 degrees), featuring a uniform precipitation intensity of 80 mm/h and a 60-minute precipitation duration post-runoff initiation. Findings evinced that annelids significantly heightened soil hydric infiltration and retention. In tanks inhabited by annelids, the increments in soil hydric retention were 93%, 51%, and 70% more elevated than those in control plots at incline gradients of 5 degrees, 10 degrees, and 15 degrees, respectively. Comparatively, earthworm activities led to a 70% reduction in runoff rate at a 5-degree slope, a 13% reduction at 10 degrees, and a 39% reduction at 15 degrees. However, soil erosion rates increased by 42% and 46% at slope gradients of 10 degrees and 15 degrees, respectively. Earthworms, through their feeding and burrowing activities, not only enhanced soil water infiltration but also mitigated surface runoff while contributing to increased soil erosion. This research proffers invaluable perspicacity regarding the influence of subterranean fauna on the vicissitudes of soil erosion processes, furnishing empirical evidence amenable for assimilation into extant soil erosion simulation paradigms or as a substratum for the construction of nascent models

Электронная библиотека Национальной библиотеки Республики Саха (Якутия): основные подходы к созданию

The upgrade project for the Electronic Library of the National Library of the Republic of Sakha (Yakutia) is discussed. The goal is to provide remote access to its digital content, to expand and develop library information services in the digital environment. The e-library enables to improve library services of the republican population and to raise the profile of the library in the modern technological world. The elibrary’s new services emerge at the synthesis of new information technologies (implementation tool) and new approaches to traditional library and bibliographic processes. The user-group oriented segments were designed ("School", "Reading since very birth", "Science in Yakutia", "Electronic publishing house") which enables to meet information demands to the fullest extent possible. The options for using personal accounts, statistical performance indicators, e-library document collection, resources selection and systematization, and grouping methods are characterized in brief. The search instrument makes an important performance indicator; it can be used for every segment and collection and is locked to descriptive metadata fields for all types of resources (formats). The concept of creating Single Library and Information Environment based on the National Library of the Republic of Sakha (Yakutia) provides the organizational and technological prospects for the e-Library.Рассмотрен проект по модернизации информационной системы «Электронная библиотека Национальной библиотеки РС (Я)», цели которой – обеспечение удалённого доступа к электронному контенту, расширение и развитие информационных услуг библиотеки в электронной среде. В данном случае электронная библиотека – это способ усовершенствовать библиотечное обслуживание населения республики и повысить статус библиотеки в современном технологическом мире. Представлены новые сервисы (услуги) электронной библиотеки как результат синтеза информационных технологий (инструмент реализации) и свежего взгляда на традиционные библиотечнобиблиографические процессы. Разработаны сегменты для разных категорий пользователей («Школа», «Читаем с рождения», «Наука Якутии», «Электронное издательство»), что позволяет наиболее полно удовлетворять информационные потребности каждой отдельно взятой группы читателей. Кратко охарактеризованы: варианты использования личного кабинета и основные статистические показатели работы; документный фонд ЭБ, отбор и организация ресурсов, методы группировки. Отмечено, что поисковый инструмент – важный показатель функциональности электронной библиотеки: он работает по всем сегментам и подборкам; ведётся по полям описательных метаданных для всех типов ресурсов (форм представления). Показаны поисковые возможности электронной библиотеки. Организационно-технологическое перспективы формирования представлены концепцией создания единой библиотечно-информационной среды на базе Национальной библиотеки Республики

ТЕОРЕТИЧЕСКИЕ, МЕТОДОЛОГИЧЕСКИЕ И СТАТИСТИЧЕСКИЕ ПРОБЛЕМЫ ИЗУЧЕНИЯ ЭКОЛОГИЧЕСКОЙ МИГРАЦИИ

The increase in the number of natural disasters that has been observed in recent decades around the world under the influence of increasing anthropogenic impact on the environment, not only often causes significant damage to the economy and infrastructure of the territories, but also causes people to die and their mass migrations. In the light of these trends, the environmental situation is increasingly becoming the subject of scientific interest of researchers of various specialties: not only climatologists, but also economists and demographers. However, despite the increasing publication activity, in particular, on problems of population migration caused by climate change and environmental problems, there are significant gaps in the theoretical and methodological aspect. Our analysis of the scientific discourse (mostly English-speaking) showed that the discrepancies concern not only the question of which immigrants should be classified as environmental or climate migrants, but also the very term “environmental migrants”, as well as the legal issue of the necessity and legality of providing such persons of refugee status. It has been established that at the moment “environmental&nbsp;refugees” do not actually have and never had refugee status, either in accordance with the relevant UN Convention or in accordance with the national legislation of any country. The article attempts to systematize and analyze the existing theoretical and methodological approaches to this problem and, on its basis, gives recommendations regarding their application. The features of statistical accounting for environmental migrants are established. The main difficulties of identifying and identifying those migration processes that resulted from changes in the environment are identified, since along with natural factors, a combination of other socio-economic factors, such as low living standards or poverty, often influence decision-making on resettlement. The principles that should be followed when organizing environmental migration statistics at the national level are given. Two groups of existing international sources of quantitative data on environmental migration are described: a bibliographic database containing materials and publications on environmental migration, as well as a database of quantitative data that provide information on the number of displaced persons. The relationship between climate change and the impact on the quality of life of the population has been identified. The negative impact of climate change on the level and quality of life of the population was identified primarily in rural areas, which led to an increase in the scale and deepening of poverty, and also caused the migration of the rural population.El aumento en el número de desastres naturales que se ha observado en las últimas décadas en todo el mundo bajo la influencia del creciente impacto antropogénico en el medio ambiente, no solo a menudo causa daños significativos a la economía y la infraestructura de los territorios, sino que también causa la muerte de personas. y sus migraciones masivas. A la luz de estas tendencias, la situación ambiental se está convirtiendo cada vez más en tema de interés científico de investigadores de diversas especialidades: no solo climatólogos, sino también economistas y demógrafos. Sin embargo, a pesar de la creciente actividad de publicación, en particular sobre los problemas de migración de la población causados por el cambio climático y los problemas ambientales, existen importantes lagunas en el aspecto teórico y metodológico. Nuestro análisis del discurso científico (en su mayoría de habla inglesa) mostró que las discrepancias se refieren no solo a la cuestión de qué inmigrantes deben clasificarse como migrantes ambientales o climáticos, sino también al término “migrantes ambientales”, así como a la cuestión legal de la necesidad y legalidad de proporcionar a tales&nbsp;personas con estatus de refugiado. Se ha establecido que en este momento los "refugiados ambientales" en realidad no tienen y nunca han tenido el estatus de refugiado, ya sea de acuerdo con la Convención de la ONU pertinente o de acuerdo con la legislación nacional de cualquier país. El artículo intenta sistematizar y analizar los enfoques teóricos y metodológicos existentes para este problema y, sobre su base, ofrece recomendaciones sobre su aplicación. Se establecen las características de la contabilidad estadística de los migrantes ambientales. Las principales dificultades para identificar e identificar aquellos procesos de migración que resultaron de cambios en el medio ambiente se identifican, ya que junto con factores naturales, una combinación de otros factores socioeconómicos, como bajos niveles de vida o pobreza, a menudo influyen en la toma de decisiones sobre el reasentamiento. . Se dan los principios que deben seguirse cuando se organizan estadísticas de migración ambiental a nivel nacional. Se describen dos grupos de fuentes internacionales existentes de datos cuantitativos sobre migración ambiental: una base de datos bibliográfica que contiene materiales y publicaciones sobre migración ambiental, así como una base de datos de datos cuantitativos que proporcionan información sobre el número de personas desplazadas. Se ha identificado la relación entre el cambio climático y el impacto en la calidad de vida de la población. El impacto negativo del cambio climático en el nivel y la calidad de vida de la población se identificó principalmente en las áreas rurales, lo que llevó a un aumento en la escala y la profundización de la pobreza, y también causó la migración de la población rural.O aumento do número de desastres naturais que tem sido observado nas últimas décadas em todo o mundo sob a influência do crescente impacto antrópico sobre o meio ambiente, não só causa danos significativos à economia e infra-estrutura dos territórios, mas também faz com que as pessoas morram e suas migrações em massa. À luz dessas tendências, a situação ambiental é cada vez mais tema de interesse científico de pesquisadores de várias especialidades: não apenas climatologistas, mas também economistas e demógrafos. No entanto, apesar da crescente atividade de publicação, em particular, nos problemas de migração populacional causados pelas mudanças climáticas e problemas ambientais, existem lacunas significativas no aspecto teórico e metodológico. Nossa análise do discurso científico (principalmente em inglês) mostrou que as discrepâncias dizem respeito não apenas à questão de quais imigrantes devem ser classificados como migrantes ambientais ou climáticos, mas também ao próprio termo “migrantes ambientais”, bem como à questão legal de migrantes. a necessidade e a legalidade de fornecer a essas pessoas o status de refugiado. Ficou estabelecido que, no momento, os “refugiados ambientais” não têm e nunca tiveram status de refugiado, seja de acordo com a Convenção da ONU ou de acordo com a legislação nacional de qualquer país. O artigo procura sistematizar e analisar as abordagens teóricas e metodológicas existentes para esse problema e, com base nisso, dá recomendações sobre sua aplicação. As características da contabilidade estatística para os migrantes ambientais são estabelecidas. As principais dificuldades de identificar e identificar os processos de migração que resultaram de mudanças no meio ambiente são identificadas, pois juntamente com fatores naturais, uma combinação de outros fatores socioeconômicos, como baixos padrões de vida ou pobreza, muitas vezes influenciam a tomada de decisões sobre o reassentamento. . Os princípios que devem ser seguidos ao organizar as estatísticas de migração ambiental em nível nacional são fornecidos. Dois grupos de fontes internacionais existentes de dados quantitativos sobre a migração ambiental são descritos: uma base de dados bibliográfica contendo materiais e publicações sobre migração ambiental, bem como uma base de dados quantitativos que fornecem informações sobre o número de pessoas deslocadas. A relação entre as mudanças climáticas e o impacto na qualidade de vida da população foi identificada. O impacto negativo da mudança climática no nível e na qualidade de vida da população foi identificado principalmente nas áreas rurais, o que levou a um aumento na escala e aprofundamento da pobreza, e também causou a migração da população rural.Увеличение числа стихийных бедствий, которое наблюдается в последние десятилетия во всем мире под влиянием усиливающегося антропогенного воздействия на окружающую среду, не только часто наносит значительный ущерб экономике и инфраструктуре территорий, но и приводит к гибели людей и их массовой миграции. В свете этих тенденций, экологическая ситуация все чаще становится предметом научного интереса исследователей различных специальностей: не только климатологи, но и экономистов и демографов. Однако, несмотря на растущую публикационную активность, в частности, по проблемам миграции населения, вызванной изменением климата и экологическими проблемами, в теоретико-методологическом аспекте имеются значительные пробелы. Проведенный нами анализ научного дискурса (в основном англоязычного) показал, что расхождения касаются не только вопроса о том, какие иммигранты должны быть классифицированы как экологические или климатические мигранты, но и самого термина “экологические мигранты”, а также юридического вопроса о необходимости и законности предоставления таким лицам статуса беженцев. Установлено, что в настоящее время “экологические беженцы” фактически не имеют и никогда не имели статуса беженца ни в&nbsp;соответствии с соответствующей конвенцией ООН, ни в соответствии с национальным законодательством какой-либо страны. В статье предпринята попытка систематизации и анализа существующих теоретико-методологических подходов к данной проблеме и на ее основе даны рекомендации по их применению. Установлены особенности статистического учета экологических мигрантов. Выявлены основные трудности выявления и идентификации тех миграционных процессов, которые обусловлены изменениями в окружающей среде, поскольку наряду с природными факторами на принятие решений о переселении зачастую влияет сочетание других социально-экономических факторов, таких как низкий уровень жизни или нищета. Принципы, которые следует соблюдать при организации статистики экологической миграции на национальном уровне. Описаны две группы существующих международных источников количественных данных об экологической миграции: библиографическая база данных, содержащая материалы и публикации по экологической миграции, а также база количественных данных, содержащая информацию о числе перемещенных лиц. Выявлена взаимосвязь между изменением климата и воздействием на качество жизни населения. Негативное влияние изменения климата на уровень и качество жизни населения было выявлено прежде всего в сельской местности, что привело к увеличению масштабов и углублению бедности, а также вызвало миграцию сельского населения

Characterization of the matrix and fusion crust of the recent meteorite fall Ozerki L6

We studied the interior and the fusion crust of the recently recovered Ozerki L6 meteorite using optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy, X-ray diffraction (XRD), magnetization measurements, and Mossbauer spectroscopy. The phase composition of the interior and of the fusion crust was determined by means of SEM, XRD, and Mossbauer spectroscopy. The unit cell parameters for silicate crystals were evaluated from the X-ray diffractograms and were found the same for the interior and the fusion crust. Magnetization measurements revealed a decrease of the saturation magnetic moment in the fusion crust due to a decrease of Fe-Ni-Co alloy content. Both XRD and Mossbauer spectroscopy show the presence of magnesioferrite in the fusion crust. The temperatures of cation equilibrium distribution between the M1 and M2 sites in silicates calculated using the data obtained from XRD and Mossbauer spectroscopy appeared to be in a good consistency: 553 and 479 K for olivine and 1213 and 1202 K for orthopyroxene.Peer reviewe

INFLUENCE OF BIOLOGIC AND SOCIAL FACTORS ON WORKING CAPABILITY OF WORKERS OF BRAINWORK

Questionnaire of 285 teachers of comprehensive schools estimated subjective fatigue and possibilities of restoration of working capacity depending on a number of biological and. social factors. From among studied factors the greatest contribution to efficiency of workers of brainwork is brought by indicators of a state of health, in particular chronic incidence, frequency of diseases in a year and. value judgment of health. The age of the worker and. level of satisfaction of the general and. professional requirements have a certain value

Determination of the dominant factor affecting the change of the phase transition point in thin ferroelectric films

The study was supported by the Russian Foundation For Basic Research, Project № 19-32-50032