Spectral properties of a 2D scalar wave equation with 1D-periodic coefficients: application to SH elastic waves

The paper provides a rigorous analysis of the dispersion spectrum of SH (shear horizontal) elastic waves in periodically stratified solids. The problem consists of an ordinary differential wave equation with periodic coefficients, which involves two free parameters $\omega$ (the frequency) and $k$ (the wavenumber in the direction orthogonal to the axis of periodicity). Solutions of this equation satisfy a quasi-periodic boundary condition which yields the Floquet parameter $K$. The resulting dispersion surface $\omega (K,k)$ may be characterized through its cuts at constant values of $K, k$ and $\omega$ that define the passband (real $K$) and stopband areas, the Floquet branches and the isofrequency curves, respectively. The paper combines complementary approaches based on eigenvalue problems and on the monodromy matrix $\mathbf{M}$. The pivotal object is the Lyapunov function $\Delta (\omega ^{2},k^{2}) \equiv 1/2\mathrm{trace}\mathbf{M}=\cos K$ which is generalized as a function of two variables. Its analytical properties, asymptotics and bounds are examined and an explicit form of its derivatives obtained. Attention is given to the special case of a zero-width stopband. These ingredients are used to analyze the cuts of the surface $\omega (K,k).$ The derivatives of the functions $\omega (k)$ at fixed $K$ and $\omega (K)$ at fixed $k$ and of the function $K(k)$ at fixed $\omega$ are described in detail. The curves $\omega (k)$ at fixed $K$ are shown to be monotonic for real $K,$ while they may be looped for complex $K$ (i.e. in the stopband areas). The convexity of the closed (first) real isofrequency curve $K(k)$ is proved thus ruling out low-frequency caustics of group velocity. The results are relevant to the broad area of applicability of ordinary differential equation for scalar waves in 1D phononic (solid or fluid) and photonic crystals.Comment: 35 pages, 4 figure

The Structure of Martian Magnetosphere at the Dayside Terminator Region as Observed on MAVEN Spacecraft

We analyzed 44 passes of the MAVEN spacecraft through the magnetosphere, arranged by the angle between electric field vector and the projection of spacecraft position radius vector in the YZ plane in MSE coordinate system (${\theta}$ E ). All passes were divided into 3 angular sectors near 0{\deg}, 90{\deg} and 180{\deg} ${\theta}$ E angles in order to estimate the role of IMF direction in plasma and magnetic properties of dayside Martian magnetosphere. The time interval chosen was from January 17 through February 4, 2016 when MAVEN was crossing the dayside magnetosphere at SZA ~ 70{\deg}. Magnetosphere as the region with prevailing energetic planetary ions is always found between the magnetosheath and the ionosphere. 3 angular sectors of dayside interaction region in MSE coordinate system with different orientation of the solar wind electric field vector E = -1/c V x B showed that for each sector one can find specific profiles of the magnetosheath, the magnetic barrier and the magnetosphere. Plume ions originate in the northern MSE sector where motion electric field is directed from the planet. This electric field ejects magnetospheric ions leading to dilution of magnetospheric heavy ions population, and this effect is seen in some magnetospheric profiles. Magnetic barrier forms in front of the magnetosphere, and relative magnetic field magnitudes in these two domains vary. The average height of the boundary with ionosphere is ~530 km and the average height of the magnetopause is ~730 km. We discuss the implications of the observed magnetosphere structure to the planetary ions loss mechanism.Comment: 24 pages, 13 figure

ОРГАНИЧЕСКАЯ АРХИТЕКТУРА: В ГАРМОНИИ С ЧЕЛОВЕКОМ И ПРИРОДОЙ

This article is devoted to three components of the organic totality: human, architecture and environment. For many years people have evolved to the environment and were an integral part of it, dwelt in harmony and unity with nature, but due to the current established processes of urbanization there is a rupture of the connection between man and environment. For this reason, urban residents may feel uncomfortable in the urban space and try to move closer to human-nature environment. One of the main tasks of modern architecture is the revival and reunification of previously lost connection of the integral system “man-environment”. Since XIX-XX centuries the rethinking of the relationship between man and nature began and it gave a push to the latest ideas in the field of architecture. It led to the beginning of organic and harmonious fusion of man, architecture and nature. The goal of this article is to identify the fusion characteristics of architecture and landscape to prove necessity to arrange the person to environmental conditions as close as possible and, therefore, comfortable conditions to the natural environment. Analyzed the state of the metropolis’ architecture and the results of environmental impact on the human, there are factors that negatively affect to psychological and physical health in the urban environment. As well the urgency of individual housing is revealed. According to the principles of the organic approach solutions of architectural urban space changes are presented.Статья посвящена вопросам органической целостности трех составляющих компонентов - человека, архитектуры и ландшафта. Одной из главных задач современной архитектуры является возрождение и воссоединение ранее утерянной связи целостной системы «человек-окружающая среда». Основные цели данной статьи заключаются в выявлении особенностей и принципов слияния архитектуры и ландшафта, а также в обосновании необходимости расположения человека в максимально приближенные, а следовательно, комфортные условия естественной природной среды. Выявлены факторы, негативно влияющие на психологическое и физическое состояние человека в условиях городской среды. Также выявлена и обоснована актуальность индивидуального строительства. На основании органического подхода представлены решения изменения архитектуры городского пространства

On the effective shear speed in 2D phononic crystals

The quasistatic limit of the antiplane shear-wave speed ('effective speed') $c$ in 2D periodic lattices is studied. Two new closed-form estimates of $c$ are derived by employing two different analytical approaches. The first proceeds from a standard background of the plane wave expansion (PWE). The second is a new approach, which resides in $\mathbf{x}$-space and centers on the monodromy matrix (MM) introduced in the 2D case as the multiplicative integral, taken in one coordinate, of a matrix with components being the operators with respect to the other coordinate. On the numerical side, an efficient PWE-based scheme for computing $c$ is proposed and implemented. The analytical and numerical findings are applied to several examples of 2D square lattices with two and three high-contrast components, for which the new PWE and MM estimates are compared with the numerical data and with some known approximations. It is demonstrated that the PWE estimate is most efficient in the case of densely packed stiff inclusions, especially when they form a symmetric lattice, while in general it is the MM estimate that provides the best overall fitting accuracy.Comment: 13 pages, 9 figure

Influence Functional State on Special Preparedness in Rock Climbing

Рукопись поступила в редакцию: 21.09.2023. Принята к публикации: 20.10.2023.Received: 21.09.2023. Accepted: 20.10.2023.В статье рассматривается проблема непропорциональности в более высоком значении ЧСС при лазании относительно беговых нагрузок при более низком уровне потребления кислорода. Целью исследования является определение влияния функционального состояния на специальную подготовленность скалолазов. В исследовании приняли участие дети в возрасте 8–12 лет, находящиеся на спортивно-оздоровительном этапе подготовки, обоего пола в количестве 24 человек. Для оценки напряжения регуляторных систем использовалась методика оценки вариабельности сердечного ритма (ВСР). В исследовании использован метод расчета специальной подготовленности, позволяющий учитывать количество наиболее сложных пройденных спортсменом боулдеринговых трасс за время тренировки и их количество. Конечный балл в большей степени зависит от сложности пролезаемой трассы. Установлено, что при лазании на простых трассах (ниже 6А по международной классификации) не наблюдается выраженных напряжений регуляторных систем организма. При росте специфических физических нагрузок в скалолазании (уровень трасс 6А‑6В) спортсмены сталкиваются с физическими усилиями требующих развития координационных и физических возможностей, несравнимых с предыдущим уровнем (трассы 5А‑5С). Также этот уровень предполагает большее психологическое напряжение. При дальнейшем усложнении специфических нагрузок в скалолазании (уровень трасс 6С) наблюдается адаптация занимающихся к предъявляемым психофизическим усилиям. Делается вывод, что постепенное возрастание значения функционального резерва ритма сердца свидетельствует об адаптации мышц рук по типу развития дыхательных способностей, к важнейшим из которых относятся возрастание значения капилляризации тканей, роста числа митохондрий и увеличение миоглобина в мышечных волокнах выполняющих специфическую работу в скалолазании.The article deals with the problem of disproportionality in a higher heart rate value when climbing relative to running loads at a lower level of oxygen consumption. The aim of the study is to determine influence of functional state on the special climbing preparedness. Study involved children aged 8–12 years in recreation stage of preparation, both sexes in the number of 24 people. To assess the voltage of regulatory systems was used a method for assessing heart rate variability. The study used a method for calculating special preparedness, which allows taking into account the number of the most difficult bouldering routes passed by an athlete during training and their number. The final score depends more on the complexity of the route. It was found that there are no pronounced stresses of the regulatory systems of the body on simple trails (below 6A according to the international classification). With the growth of specific physical loads in rock climbing (the level of trails 6A‑6B), athletes face physical efforts requiring the development of coordination and physical capabilities incomparable with the previous level (trails 5A‑5S). Also, this level implies more psychological stress. In further complication of specific loads in rock climbing (6C level of trails) is observed the adaptation to the psychophysical efforts. It is concluded that with the growth of functional reserve the heart rhythm increases the adaptation of hands muscles to greater oxygen absorption. Increases tissue capillarization, number of mitochondria and myoglobin in muscle fibers performing specific work in climbing

Enabling magnetic resonance imaging of hollow-core microstructured optical fibers via nanocomposite coating

Optical fibers are widely used in bioimaging systems as flexible endoscopes capable of low-invasive penetration inside hollow tissue cavities. Here, we report on the technique which allows magnetic resonance imaging (MRI) of hollow-core microstructured fibers (HC-MFs), paving the way for combing MRI and optical bioimaging. Our approach is based on Layer-by-Layer assembly of oppositely charged polyelectrolytes and magnetite nanoparticles on the inner core surface of HC-MFs. Incorporation of magnetite nanoparticles into polyelectrolyte layers renders HC-MFs visible for MRI and induces the red-shift in their transmission spectra. Specifically, the transmission shifts up to 60 nm have been revealed for the several-layers composite coating along with the high-quality contrast of HC-MFs in MRI scans. Our results shed light on marrying fiber-based endoscopy with MRI that opens novel possibilities for minimally invasive clinical diagnostics and surgical procedures in vivo.Comment: 11 pages, 6 figure

Genetic diversity of potato varieties bred in Russia and near-abroad countries based on polymorphism of SSR-loci and markers associated with resistance R-genes

The genetic diversity of potato varieties from the VIR collection was analyzed based on microsatellite analysis. These varieties have been bred in Russia and near-abroad countries since the 1931. Application of 14 highly polymorphic nuclear microsatellites (SSR) enabled the complete discrimination of all 113 varieties. Additionally, we have studied these varieties for the distribution of 8 DNA markers associated with three R-genes involved in the control of resistance to two quarantine objects: the potato wart Synchytrium endobioticum and golden potato cyst nematode Globodera rostochiensis, which occur locally in some regions of the Russian Federation. All the analyzed varieties with resistance to S. endobioticum pathotype 1 revealed the diagnostic marker Nl-251400 of the Sen1 gene and a few susceptible cultivars lost this diagnostic fragment. The tested markers of the H1 and Gro1-4 genes, which confer resistance to G. rostochiensis pathotype Ro1 revealed different predictiveness. In the molecular screening of potato varieties, it is better to use several markers of these genes. Results of molecular screening using six markers of the H1 and Gro1-4 genes allowed us to detect 6 haplotypes in the tested subset. Five haplotypes include varieties with different combinations of the markers tested, the majority (87.9 %) of these varieties were highly resistant or moderately resistant to G. rostochiensis. The most numerous haplotype H1/0 included 76 varieties, which did not possess any marker; 96.1 % of these varieties were susceptible to G. rostochiensis. Predictive associations between haplotype content, wart and nematode resistance, pedigree and ‘variety age’ are discussed

Open and Hidden Charm Production in 920 GeV Proton-Nucleus Collisions

The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B spectrometer covers negative values of xF up to xF=-0.3 and a broad range in transverse momentum from 0.0 to 4.8 GeV/c. The studies presented in this paper include J/psi differential distributions and the suppression of J/psi production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.Comment: 5 pages, 9 figures, to be published in the proceedings of the 6th International Conference on Hyperons, Charm & Beauty Hadrons (BEACH04), Chicago, IL, June 27 - July 3, 200