A small parameter approach for few-body problems

A procedure to solve few-body problems is developed which is based on an expansion over a small parameter. The parameter is the ratio of potential energy to kinetic energy for states having not small hyperspherical quantum numbers, K>K_0. Dynamic equations are reduced perturbatively to equations in the finite-dimension subspace with K\le K_0. Contributions from states with K>K_0 are taken into account in a closed form, i.e. without an expansion over basis functions. Estimates on efficiency of the approach are presented.Comment: 17 pages, 1 figur

The types of physical health-improving technologies and their application in higher education

In this work, we determined the types of physical health-improving technologies, their content and influence on the organism of student young people, and considers the organizational-methodical aspects of modern health technologies in higher educationВ данной работе были определены виды физкультурно-оздоровительных технологий, их содержание и влияние на организм студенческой молодежи, а также рассмотрены организационно-методические аспекты современных оздоровительных технологий в высших учебных заведения

Probing guided monolayer semiconductor polaritons below the light line

In this work, we demonstrate an approach to study exciton-polaritons supported by transition metal dichalcogenide monolayers coupled to an unstructured planar waveguide below the light line. In order to excite and probe such waves propagating along the interface with the evanescent fields exponentially decaying away from the guiding layer, we employ a hemispherical ZnSe solid immersion lens (SIL) precisely positioned in the vicinity of the sample. We visualize the dispersion of guided polaritons using back focal (Fourier) plane imaging spectroscopy with the high-NA objective lens focus brought to the center of SIL. This results in the effective numerical aperture of the system exceeding an exceptional value of 2.2 in the visible range. In the experiment, we study guided polaritons supported by a WS2 monolayer transferred on top of a Ta2O5 plane-parallel optical waveguide. We confirm room-temperature strong light-matter coupling regime enhanced by ultra-low intrinsic ohmic and radiative losses of the waveguide. Note that in the experiment, total radiative losses can be broadly tuned by controlling SIL-to-sample distance. This gives a valuable degree of freedom for the study of polariton properties. Our approach lays the ground for future studies of light-matter interaction employing guided modes and surface waves

Effects of limited introgressions from Triticum timopheevii Tausch. into the genome of bread wheat (Triticum aestivum L.) on physiological and biochemical traits under normal watering and drought

Alien hybridization in cereals is used for comparative investigations of genome structure and evolution as well as for extracting useful genes from the wild gene pool. The tetraploid species Triticum timopheevii has long been used as a source of genes for resistance to fungal diseases. Line 821 was developed on the genetic background of cultivar Saratovskaya 29 (S29), which is drought-resistant but is very susceptible to diseases and carries big introgressions in 2A and 2B chromosomes and a small introgression in the subtelomeric region of 5A chromosome. The two genotypes were compared for the parameters associated with direct and indirect reaction of the photosynthetic apparatus to water stress. In flag leaves of 821 line, an increased transpiration rate and stomatal conductance (1.6 times the value in optimal watering and 1.2 times the value under water deficit) and, correspondingly, reduced water use efficiency were found compared to the initial cultivar. Additionally, the actual effectiveness and electron transport rate of photosystem II and chlorophyll and carotenoid content were reduced as well as the total antioxidant capacity (approximately three-fold) under water stress. Under the same conditions, lipoxygenase activity was increased two-fold. On the whole, water deficit tolerance was decreased in the line in comparison with the parental cultivar and was accompanied by leaf senescence. Thus, it may be supposed that 2A, 2B and 5A chromosomes of the drought-tolerant cultivar S29 carry important genetic factors responsible for reaction to water stress in wheat plants

Physiological responses to water deficiency in bread wheat (Triticum aestivum L.) lines with genetically different leaf pubescence

Studying the relationship between leaf pubescence and drought resistance is important for assessing Triticum aestivum L. genetic resources. The aim of the work was to assess resistance of common wheat genotypes with different composition and allelic state of genes that determine the leaf pubescence phenotype. We compared the drought resistance wheat variety Saratovskaya 29 (S29) with densely pubescent leaves, carrying the dominant alleles of the Hl1 and Hl3 genes, and two near isogenic lines, i: S29 hl1, hl3 and i: S29 Hl2aesp, with the introgression of the additional pubescence gene from diploid species Aegilops speltoides. Under controlled conditions of the climatic chamber, the photosynthetic pigments content, the activity of ascorbate-glutathione cycle enzymes and also the parameters of chlorophyll fluorescence used to assess the physiological state of the plants photosynthetic apparatus were studied in the leaves of S29 and the lines. Tolerance was evaluated using the comprehensive index D, calculated on the basis of the studied physiological characteristics. The recessive state of pubescence genes, as well as the introduction of the additional Hl2aesp gene, led to a 6-fold decrease in D. Under the water deficit influence, the fluorescence parameters profile changed in the lines, and the viability index decreased compared with S29. Under drought, the activity of ascorbate peroxidase, glutathione reductase and dehydroascorbate reductase in the line i: S29 hl1, hl3 decreased 1.9, 3.3 and 2.3 times, in the line i: S29 Hl2aesp it decreased 1.8, 3.6 and 1.8 times respectively, compared with S29. In a hydroponic greenhouse, line productivity was studied. Compared with S29, the thousand grains mass in the line i: S29 hl1, hl3 under water deficit was reduced. The productivity of the line i: S29 Hl2aesp was significantly reduced regardless of water supply conditions in comparison with S29. Presumably, the revealed effects are associated with violations of cross-regulatory interactions between the proteins of the trichome formation network and transcription factors that regulate plant growth and stress response

Neutron-3H and Proton-3He Zero Energy Scattering

The Kohn variational principle and the (correlated) Hyperspherical Harmonics technique are applied to study the n-3H and p-3He scattering at zero energy. Predictions for the singlet and triplet scattering lengths are obtained for non-relativistic nuclear Hamiltonians including two- and three-body potentials. The calculated n-3H total cross section agrees well with the measured value, while some small discrepancy is found for the coherent scattering length. For the p-3He channel, the calculated scattering lengths are in reasonable agreement with the values extrapolated from the measurements made above 1 MeV.Comment: 13 pages, REVTEX, 1 figur

Layered Synthesis of Workpieces by the Method of Mig-Pulse Surface with the Use of Austenitic Metal-Core Wire with Nitrogen

Works were carried out on the synthesis of a workpiece using metal-cored wire with nitrogen (0,322 wt. %) using the mig-pulse-technology. It was possible to obtain a defect-free dense deposited metal with high strength and plastic characteristics.Работа выполнена при финансовой поддержке Министерства науки и высшего образования Российской Федерации (государственное задание № FSNM-2021-0011) и Российского фонда фундаментальных исследований (проект РФФИ 20-48-596006 р_НОЦ_Пермский край)

Topology of the spaces of Morse functions on surfaces

Let $M$ be a smooth closed orientable surface, and let $F$ be the space of Morse functions on $M$ such that at least $\chi(M)+1$ critical points of each function of $F$ are labeled by different labels (enumerated). Endow the space $F$ with $C^\infty$-topology. We prove the homotopy equivalence $F\sim R\times{\widetilde{\cal M}}$ where $R$ is one of the manifolds ${\mathbb R}P^3$, $S^1\times S^1$ and the point in dependence on the sign of $\chi(M)$, and ${\widetilde{\cal M}}$ is the universal moduli space of framed Morse functions, which is a smooth stratified manifold. Morse inequalities for the Betti numbers of the space $F$ are obtained.Comment: 15 pages, in Russia