204 research outputs found
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 educationΠ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΠ΅ Π±ΡΠ»ΠΈ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Ρ Π²ΠΈΠ΄Ρ ΡΠΈΠ·ΠΊΡΠ»ΡΡΡΡΠ½ΠΎ-ΠΎΠ·Π΄ΠΎΡΠΎΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΉ, ΠΈΡ
ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ ΠΈ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΠΎΡΠ³Π°Π½ΠΈΠ·ΠΌ ΡΡΡΠ΄Π΅Π½ΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠΎΠ»ΠΎΠ΄Π΅ΠΆΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΎΠ½Π½ΠΎ-ΠΌΠ΅ΡΠΎΠ΄ΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π°ΡΠΏΠ΅ΠΊΡΡ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΠΎΠ·Π΄ΠΎΡΠΎΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΉ Π² Π²ΡΡΡΠΈΡ
ΡΡΠ΅Π±Π½ΡΡ
Π·Π°Π²Π΅Π΄Π΅Π½ΠΈΡ
VΠ ΠΡΠΆΠ½Π°ΡΠΎΠ΄Π½Π° Π½Π°ΡΠΊΠΎΠ²ΠΎ-ΠΏΡΠ°ΠΊΡΠΈΡΠ½Π° ΠΊΠΎΠ½ΡΠ΅ΡΠ΅Π½ΡΡΡ Β«Π§ΠΈΡΡΠ° Π²ΠΎΠ΄Π°. Π€ΡΠ½Π΄Π°ΠΌΠ΅Π½ΡΠ°Π»ΡΠ½Ρ, ΠΏΡΠΈΠΊΠ»Π°Π΄Π½Ρ ΡΠ° ΠΏΡΠΎΠΌΠΈΡΠ»ΠΎΠ²Ρ Π°ΡΠΏΠ΅ΠΊΡΠΈΒ»
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 theΒ 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) underΒ 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
Significant influence of metal surface morphology on photon emission from a local tunnel junction at ambient conditions
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.Π Π°Π±ΠΎΡΠ° Π²ΡΠΏΠΎΠ»Π½Π΅Π½Π° ΠΏΡΠΈ ΡΠΈΠ½Π°Π½ΡΠΎΠ²ΠΎΠΉ ΠΏΠΎΠ΄Π΄Π΅ΡΠΆΠΊΠ΅ ΠΠΈΠ½ΠΈΡΡΠ΅ΡΡΡΠ²Π° Π½Π°ΡΠΊΠΈ ΠΈ Π²ΡΡΡΠ΅Π³ΠΎ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ Π ΠΎΡΡΠΈΠΉΡΠΊΠΎΠΉ Π€Π΅Π΄Π΅ΡΠ°ΡΠΈΠΈ (Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ²Π΅Π½Π½ΠΎΠ΅ Π·Π°Π΄Π°Π½ΠΈΠ΅ β FSNM-2021-0011) ΠΈ Π ΠΎΡΡΠΈΠΉΡΠΊΠΎΠ³ΠΎ ΡΠΎΠ½Π΄Π° ΡΡΠ½Π΄Π°ΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΡ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ (ΠΏΡΠΎΠ΅ΠΊΡ Π Π€Π€Π 20-48-596006 Ρ_ΠΠΠ¦_ΠΠ΅ΡΠΌΡΠΊΠΈΠΉ ΠΊΡΠ°ΠΉ)
Topology of the spaces of Morse functions on surfaces
Let be a smooth closed orientable surface, and let be the space of
Morse functions on such that at least critical points of each
function of are labeled by different labels (enumerated). Endow the space
with -topology. We prove the homotopy equivalence where is one of the manifolds , and the point in dependence on the sign of ,
and is the universal moduli space of framed Morse
functions, which is a smooth stratified manifold. Morse inequalities for the
Betti numbers of the space are obtained.Comment: 15 pages, in Russia
- β¦