Hengzongshu/ArticleAgent huggingface dataset:
Philosophy and mathematics go hand by hand from at least the time of Plato. Despite differences in their subject matter, they share their strife for truth and attitude towards deductive reasoning. The paper aims to highlight these points and demonstrate the changes mathematical education underwent in its birthplace, the Egyptian Alexandria, in Late Antiquity, the changes which affected both its content and the way of presentation, influenced by the Neoplatonic method of commentary. The figures discussed in the paper — the mathematicians of the fourth century Pappus, Theon and Hypatia — both actively participated in the process of commenting on the classical works of Euclid, Apollonius, Ptolemy, Aratus, and Diophantus and made their own, although minor and mostly methodological, contributions to arithmetic, geometry, astronomy and harmonics. The points are further illustrated by a selection of fragments from the Neoplatonic Damascius, who in his lost Philosophical history presents us with the whole gallery of philosophical portraits in Athens, Alexandria and elsewhere, such as mysterious and ascetic Isidore, pragmatic Asclepiadotus and Hegias, sober and diligent Marinus, the successor of Proclus, who, unlike his teacher, in his exegeses of the Parmenides thought that the dialogue deals with species rather than gods.
Preliminary results of the SND experiment at the VEPP-2000 e+e− collider are presented. Data corresponding to about 40 pb−1 of integrated luminosity were collected in the e+e− c.m. energy range from 1.05 to 2.00 GeV. The cross sections for e+e− → ωπ0, π+π−4π0, , have been measured.
Fifty-three species of perennial grasses in the genus Elymus L. (Poaceae), which are widespread in Russia, are generally assumed to have three haplome combinations: StH, StY and StHY. The StH-genome species, endemic to Russia, remain the least studied. R. Mason-Gamer and co-authors have previously shown in a series of studies that a molecular phylogenetic analysis of the low-copy gene waxy (GBSS1) sequences significantly complements cytogenetic data on the genomic constitution and evolutionary relationships among both North American and Asian species of the genus Elymus.

To determine the species’ genomic constitution and to evaluate the level of phylogenetic differentiation, we examined the GBSS1 gene in 18 species of Elymus from Siberia and the Russian Far East, including the following 14 endemics: E. charkeviczii, E. jacutensis, E. kamczadalorum, E. komarovii, E. kronokensis, E. lenensis, E. macrourus, E. margaritae, E. subfibrosus, E. sajanensis, E. transbaicalensis, E. peschkovae, E. uralensis, and E. viridiglumis.PCR amplification products of GBSS1 gene fragments (including exons 9–14) were cloned and 6–8 clones per accession were sequenced.

It appears that all the species studied have St and H subgenomic gene variations. The most significant differences between the subgenomic variants St and H were found in intron 13. The H subgenome contains a 21-bp-long deletion in intron 13 in all Elymus genotypes, probably derived from a common ancestor of the H and P genomes. Instead of this deletion, all St subgenomes have a relatively conservative sequence similar to that of the genus Pseudoroegneria, whose ancestor is considered to be the donor of the modern St subgenome for all Elymus species. Cluster phylogenetic analysis revealed differentiation in St and H subgenome sequences into two evolutionary variants: St1 vs. St2 and H1 vs. H2, respectively. Variants of the St and H subgenomes were found homologous to various modern species of the ancestral genera Pseudoroegneria and Hordeum: St1 to P. strigosa, St2 to P. spicata, H1 to H. jubatum, and H2 to H. californicum. The details of the relationships between Russian and North American species of the genus, as well as a number of microevolutionary interconnections in the group of boreal endemic species of Siberia and the Russian Far East were revealed. The new results obtained here are essential for the development of a phylogenetically oriented taxonomic system for the genus Elymus.
To change the wavelength of undulator radiation, variation of the undulator magnetic field amplitude is frequently applied. Another option is changing the undulator period.

A corresponding scheme is described. Both the period and number of periods can be changed. For a set of undulator sections (as in the x-ray free-electron lasers ), the mechanical motion of the periods allows doing without phase shifters between the undulator sections. Magnetic field calculations for some undulator parameters of interest were performed.

Numerous advantages of the new undulators (fixed gap, strong dependence of the undulator radiation wavelength on the period, relatively low field amplitude variation, and variable number of periods) look very attractive. The prospects for this new type of undulators are discussed.
In this paper, we use a fully coupled model for 3D planar fracture propagation within a poroelastic reservoir in order to analysis the non-symmetry of the fracture as it develops in a 3-layer reservoir with different compressive stresses in each layer. We demonstrate that the fracture predominantly develops in the layer with the lower compressive stress until it gets arrested due to the equality of the total leakoff to the volume of pumped fluid.
A test facility for experimental simulation of transient heat loads in ITER divertor with the use of high power electron beam is developed at the Budker Institute of Nuclear Physics. This report presents an experimental study of the absorption of the electron beam with an incident heat power flux of 10-50 GW/m2 on the area of about 2 cm2 of a tungsten target. The electron beam has duration of 0.1-0.3 ms and electron energy of 80-95 keV, Diagnostics for measuring of the beam parameters on the target are briefly discussed. Results of measurement of the beam profile and calorimetry of beam energy deposited in tungsten sample at ELM-like heat load are presented.
The article raises issues related to written fixation of the oral Mennonite language called Plautdietsch. The Mennonites – members of one of the Protestant churches, established first in Holland and northern Germany – changed their place of residence over the centuries. The Mennonite language emerged in Prussia and later in Ukraine, where their large colonies had lived. Being a striking feature of this specific ethno-confessional community, Plautdietsch was and still is used almost exclusively in oral communication and does not have any established written standard. The phonology of Plautdietsch may be identified, in general, as Low German, although there is a number of significant phonological features are not characteristic of Low German area. Now the Plautdietsch native speakers live all over the world: in Canada, Germany, Russia, in particular, in Siberia, where their own, yet unstable, written standard of the language is being formed. One of the main problems concerning its fixation is caused by the complicated vocalism and high instability observed in the pronunciation of many vowels and diphthongs, the main source of difficulties preventing elaboration of the means for writing. In this paper, we focus on these unstable features of the vocal system. It provides a brief overview of currently available written samples of Plautdietsch, produced in Canada, Germany, and Russia. Some of them are based on the Latin alphabet and norms of the German spelling. Others, on the contrary, depart from it, using specific letter combinations, unknown earlier, introducing geminates (double consonants), refusing to spell nouns with a capital letter or to use umlauts (for technical convenience). Developments and tentative approaches of some Germanists from Russia who introduced their own ways of writing Plautdietsch in their research papers are presented. As an illustration, the samples of such a graphic system, elaborated by the linguist from Novosibirsk I. A. Kanakin (1940–2018), are given. They were not published and are kept in the personal archive of the author of the article. Our own principle of writing is presented too, and this as a part of the project implementation – compiling and publishing a small handbook for reading in this language, which is addressed to children, whose native language is Plautdietsch and who study literary German at school. Taking this into account, the most appropriate ad-hoc solution seems to use a form of writing that is close to German spelling and is accepted today in Germany.
The results of thermodynamic calculations for a water-rock system in the Upper Jurassic deposits of the Arctic regions of Western Siberia are presented. In the area under investigation the groundwaters have been identified with mineralization up to 63.3 g/L and various chemical composition and genesis. Despite the long interaction with the rock (150-160 ma) equilibrium with endogenous minerals (albite, microcline and anorthite) is practically not observed. At the same time, groundwaters are in equilibrium with clay minerals and micas, such as: Caand Na-montmorillonites, kaolinite, paragonite, margarite, illite, muscovite and Mg-chlorite. The establishment of a balance of groundwater with primary aluminosilicate minerals is also affected by interactions with carbonate minerals. The differences in composition of groundwater in equilibrium with certain aluminosilicates and carbonates indicate that the mineral changes are formed from a solution of a strictly defined chemical composition in an appropriate geochemical environment.
The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics.

The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources.

A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology.
A quasi-classical approximation is constructed to describe the eigenvalues of the magnetic Laplacian on a compact Riemannian manifold in the case when the magnetic field is given by a non-exact 2-form.

For this, the multidimensional WKB method in the form of the Maslov canonical operator is applied. In this case, the canonical operator takes values in sections of a non-trivial line bundle.

The constructed approximation is demonstrated for the example of the Dirac magnetic monopole on the two-dimensional sphere.
The invariant mass spectrum of the ${\ensuremath{\eta}}^{\ensuremath{'}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ final state produced in two-photon collisions is obtained using a $673\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected in the vicinity of the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. We observe a clear signal of the ${\ensuremath{\eta}}_{c}(1S)$ and measure its mass and width to be $M({\ensuremath{\eta}}_{c}(1S))=(2982.7\ifmmode\pm\else\textpm\fi{}1.8(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2.2(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}0.3(\mathrm{\text{model}}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and $\ensuremath{\Gamma}({\ensuremath{\eta}}_{c}(1S))=({37.8}_{\ensuremath{-}5.3}^{+5.8}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2.8(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}1.4(\mathrm{\text{model}}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$. The third error is an uncertainty due to possible interference between the ${\ensuremath{\eta}}_{c}(1S)$ and a nonresonant component. We also report the first evidence for $\ensuremath{\eta}(1760)$ decay to ${\ensuremath{\eta}}^{\ensuremath{'}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$; we find two solutions for its parameters, depending on the inclusion or not of the $X(1835)$, whose existence is of marginal significance in our data. From a fit to the mass spectrum using coherent $X(1835)$ and $\ensuremath{\eta}(1760)$ resonant amplitudes, we set a 90% confidence level upper limit on the product ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}\mathcal{B}({\ensuremath{\eta}}^{\ensuremath{'}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})$ for the $X(1835)$.
Apart from a lot of fundamental interest, vector Bessel beams are widely used in optical manipulation, material processing, and imaging. However, the existing description of such beams remains fragmentary, especially when their scattering by small particles is considered. We propose a general classification of all existing vortex Bessel beam types in an isotropic medium based on the superposition of transverse Hertz vector potentials. This theoretical framework contains duality and coordinate rotations as elementary matrix operations and naturally describes all relations between various beam types. This leads to various bases for Bessel beams and uncovers a different beam type with circularly symmetric energy density. We also discuss quadratic functionals of the fields (such as the energy density and Poynting vector) and derive orthogonality relations between various beam types. Altogether, it provides a comprehensive reference of all properties of Bessel beams that may be relevant for applications. Next, we generalize the formalism of the Mueller scattering matrices to arbitrary Bessel beams accounting for their vorticity. Finally, we implement these beams in the adda code---an open-source parallel implementation of the discrete dipole approximation. This enables easy and efficient simulation of Bessel beam scattering by particles with arbitrary shape and internal structure.
We propose and demonstrate that a gamma-gamma collider with W_gg < 12 GeV can be added to the European XFEL with a minimal disruption to its main program. High-energy photons will be obtained by Compton scattering of 0.5 micron laser photons on the existing 17.5 GeV electron beams. Such a gamma-gamma collider would be an excellent place for the development and application of modern technologies: powerful lasers, optical cavities, superconducting linacs, and low-emittance electron sources -- as well as training the next generation of accelerator physicists and engineers. The physics program would include spectroscopy of C=+ resonances in various J^P states b\bar{b}, c\bar{c}, four-quark states, quark molecules and other exotica) in a mass range barely scratched by past and not covered by any current or planned experiments. Variable circular and linear polarizations will help in the determination of quantum numbers and measurement of polarization components of the gamma-gamma cross section (\sigma_\perp, \sigma_\parallel, \sigma_0, \sigma_2).
The high mortality rate that accompanies cancer spurs the search for new methods that can be used to treat malignant neoplasms. In addition to chemotherapy, electrophysical techniques for tumor treatment appear rather promising.

The results of in vitro exposure of A549 human lung adenocarcinoma cells to cold atmospheric plasma (CAP) are hereby presented. A gas-discharge device that generates a sequence of streamers propagating along a stream of inert gas in the ambient air was used. In the zone where the plasma jet came into contact with the target object, there were high-intensity electric fields and high plasma concentrations, while the gas temperature changed by less than a degree. In this study, we compared the cytotoxic effect of CAP in helium and argon. Direct irradiation of cells by CAP with U = 4.2 kV for 30-120 s was shown to reduce cell viability by 25%.

Variation of the amplitude of the AC voltage in the plasma device in argon within a range of 3.8-5.6 kV did not significantly alter the cell death rate. Further optimization of the modes of CAP generation in gas-discharge devices with various geometries for the trea.
Several examples of the comparative variable-temperature and variable-pressure studies of the small-molecule organic crystals are discussed. Selected systems represent the crystals with nonspherical flexible molecules / molecular fragments and with different types of intermolecular interactions, ranging from van der Waals interactions to hydrogen bonds of various types (OH…O, NH…OH, NH…O=C).

A special attention is payed to the studies of solid drugs (polymorphs of paracetamol), amino acids (polymorphs of glycine, L-serine, D,L-serine), and dipeptides (glycilglycine and glycilglycine hydrate) by structural, spectroscopic and calorimetric techniques.

The anisotropy of structural distortion within the range of stability of the same phase, as well as the phase transitions induced by changes in temperature or pressure are discussed.
The authors of this scientific paper examine the current situation in the Russian Federation associated with the pollution of water and the atmospheric resources, with the problem of production and consumption waste accumulation, and draw their attention to the imperfection of statistical information, which does not allow for an objective assessment of the environmental situation. The quality of natural resources is not improving despite the statistical decrease in emissions and discharges of pollutants.

The article is devoted to the analyses of the 'green' investment processes in Russia. The author's definition of 'green' investment is given.

They concluded an inconsistency of the economic development in the Russian Federation with the principles of sustainability and the 'green' economy. It is necessary to intensify investment activities to protect the natural environment, in order to change the situation. At present, the share of the environmental investments in all national economic capital investments is negligible - less than 1%. The sluggish dynamic of investment processes led to insufficient commissioning of the main environmental funds. Recently, the situation has worsened in connection with the sequestration of the national project 'Ecology' due to the pandemic problems.
Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate.

We report the first search for a stable, doubly strange six-quark state in ϒ→SΛ[over ¯]Λ[over ¯] decays based on a sample of 90×10^{6}ϒ(2S) and 110×10^{6}ϒ(3S) decays collected by the BABAR experiment.

No signal is observed, and 90% confidence level limits on the combined ϒ(2S,3S)→SΛ[over ¯]Λ[over ¯] branching fraction in the range (1.2-1.4)×10^{-7} are derived for m_{S}<2.05 GeV. These bounds set stringent limits on the existence of such exotic particles.
This paper is devoted to experimental investigation of formation of precessing vortices pair in a vortex chamber with a cylindrical working area.

Flow structure was registered by means of a high-speed visualization technique. Quantitative measurements characterizing the vortex properties were carried out using a 2D particle image velocimetry (PIV) technique synchronized with wall pressure measurements.

The results show that two symmetrical precessing helical vortices are present downstream of the tangential nozzles. The phase-averaged analysis confirms the presence of large-scale twin vortex structure that visualized by small air bubbles dissolved in water.
We search for lepton-number- and baryon-number-violating decays using data recorded with the Belle detector at the KEKB asymmetric-energy collider.

Analysis of 921 fb⁻¹ of data, equivalent to (841±12)×10⁶ τ⁺τ⁻ events, to search for specific decay channels.

In the absence of a signal, 90% confidence-level upper limits are set on the branching fractions in the range (1.8-4.0)×10⁻⁸, setting world's first limits on some channels and improving existing limits by an order of magnitude for others.
We study the free boundary problem for a plasma-vacuum interface in ideal incompressible magnetohydrodynamics. Unlike the classical statement when the vacuum magnetic field obeys the div-curl system of pre-Maxwell dynamics, to better understand the influence of the electric field in vacuum we do not neglect the displacement current in the vacuum region and consider the Maxwell equations for electric and magnetic fields. Under the necessary and sufficient stability condition for a planar interface found in [Trakhinin Y. arXiv:1812.08675], we prove an energy a priori estimate for the linearized constant coefficient problem. The process of derivation of this estimate is based on various methods, including a secondary symmetrization of the vacuum Maxwell equations, the derivation of a hyperbolic evolutionary equation for the interface function and the construction of a degenerate Kreiss-type symmetrizer for an elliptic-hyperbolic problem for the total pressure.
The paper describes a computational program developed in MatLab Simulink, that performs calculation of electric power generated by photoconverters for various missions of nanosatellites in low Earth orbit (LEO). Electric power generated by nanosatellite’s solar panels was estimated for polar LEO of 450 km altitude for two versions of the satellite’s static orientation. The results show how orientation maneuver at the Earth’s surface point affects power generated by the satellite’s solar panels.
The work explores the three-dimensional structure of the near field of a quasi-two-dimensional turbulent jet. The jet stream forms at an outflow from the rectangular channel with aspect ratio B/h equal to 1:2.5 into the channel, formed by two plane-parallel plates.

The experiments were carried out for a wide range of Re number from 2 000 to 20 000. The measurements were performed using Tomographic PIV method with high time resolution.

It is shown that for the whole investigated range of Re number in the near-field of the quasi-two-dimensional jet, there are formed secondary flows, caused by the presence of longitudinal vortex structures in the flow.
Existence of the density limit in the helicon plasma sources is critically revisited. The low- and high-frequency regimes of a helicon plasma source operation are distinguished. In the low-frequency regime with $\omega \sqrt{\omega_{ci}\omega_{ce}}$, an appropriate limit is given by the Shamrai-Taranov criterion. Both these criteria are closely related to the phenomenon of the coalescence of the helicon wave with the Trivelpiece-Gould mode. We argue that theoretical density limits are not achieved in existing devices but might be met in the future with the increase of applied rf power.
The word 'melanin' refers to a group of high molecular weight, black and brown pigments formed through the oxidation and polymerization of phenolic compounds. This pigment is present in all kingdoms of living organisms, but it remains the most enigmatic pigment in plants. The poor solubility of melanin in particular solvents and its complex polymeric nature significantly constrain its study. Plant melanin synthesis is mostly associated with the enzymatic browning reaction that occurs in wounded plant tissues. This reaction occurs when, due to the disruption of cellular compartmentation, the chloroplast-located polyphenol oxidases release from the chloroplast and interact with their vacuolar substrates to produce o-quinones, which in turn polymerize to melanin. Furthermore, the presence of melanin in intact seed tissues has been demonstrated by diagnostic physicochemical tests. Unlike the well-studied enzymatic browning reaction, little is known about how melanin is formed in seeds. Recent data have shown that it is a tightly controlled genetic process that involves many genes, among which the genes encoding polyphenol oxidases might be key. The present article aims to provide an overview of the current knowledge on melanin in plants and to discuss future perspectives on its study in light of recent findings.