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A bstract A method for measuring the average longitudinal polarization of the electron beam at an electron-positron collider operating near the J / ψ resonance is proposed. The method utilizes the differential cross-section of J / ψ → Λ → p π − Λ → p ¯ π + decay. It can be used to measure the average longitudinal polarization of electrons with the statistical precision better than 10 −3 at a Super Charm-Tau factory operating at the luminosity of 10 35 cm −2 s −1 . The method is discussed in the context of the weak mixing angle measurement in the same experiment.

A series of benzotriazole, cyclic amides and pyrimidine derivatives, containing 2,6-di-tert-butyl-phenol fragments, were synthesized. The redox properties of obtained compounds were studied using the cyclic voltammetry on a platinum electrode in acetonitrile. The oxidation potentials of all substances were comparable to those of BHT. The obtained compounds were tested for their antibacterial activity, and N-(2-(3,5-di-tert-butyl-4-hydroxyphenyl)-2-oxoethyl)isatin (32 μg/mL) exerted good activity against Staphylococcus aureus.

In this work, a series of thiosemicarbazones with phenol fragments were used as starting compounds for the synthesis of new effective antioxidants containing both a phenol substituent and a heterocyclic fragment: thiazole and thiazolidinone. To determine the most stable conformation of thiosemicarbazone, a potential energy scan was used, along with NOESY NMR spectroscopy data. A number of thiazole derivatives were obtained due the interaction of thiosemicarbazones with several bromoketones: bromoacetophenone, bromodimedone, and bromoacetylcoumarin. The product yields varied from 71 to 94%. Thiazolidinone derivatives were obtained through the reaction between thiosemicarbazones and chloroacetic acid or maleic anhydride with good yields of 82–95%. The antioxidant activities of all the products were determined in vitro: the radical cation scavenging activity was estimated using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate), while the ferric reducing capacity was determined using the ferricyanide/Prussian blue method. It was found that the antioxidant activity of most synthesized substances in both tests exceeds the activity of 4-methyl-2,6-di-tert-butylphenol, while derivatives with a fragment of 2,6-di-tert-butylphenol have the highest activity.

The Pot, Atom, and Step Economy (PASE) approach is based on the Pot economy principle and unites it with the Atom and Step Economy strategies; it ensures high efficiency, simplicity and low waste formation. The PASE approach is widely used in multicomponent chemistry. This approach was adopted for the synthesis of previously unknown hydroxyquinolinone substituted chromeno[2,3-b]pyridines via reaction of salicylaldehydes, malononitrile dimer and hydroxyquinolinone. It was shown that an ethanol-pyridine combination is more beneficial than other inorganic or organic catalysts. Quantum chemical studies showed that chromeno[2,3-b]pyridines has potential for corrosion inhibition. Real time 1H NMR monitoring was used for the investigation of reaction mechanism and 2-((2H-chromen-3-yl)methylene)malononitrile was defined as a key intermediate in the reaction.

This paper presents a method for preparing data for machine learning for semantic segmentation of informative classes in images based on clustering for solving problems of space monitoring of impact areas. A classification of clustering methods by various criteria is given. The choice of hierarchical clustering methods as the most effective for working with clusters of arbitrary structure and shape is substantiated. A general scheme for calculating a clustering model is given, which includes, in addition to the clustering itself, procedures for data tiling, estimating the optimal clustering parameters, registering objects, and assessing the quality of the obtained data. A scheme for preparing data for machine learning is shown, including the construction of a reference markup, calculation of a clustering model, markup correction, and testing the obtained clustering models for different informative classes on new images.

Landfill biogas contains large amounts of toxic and harmful impurities and may be a source of microbiological contamination of both the complex municipal waste landfill itself and adjacent territories. This paper uses modern biotechnologies designed to protect the environment to study the quantitative and qualitative composition of biogas for harmful factors, as well as for harmful substance removal from biogas. An assessment was made of air purification in the premises near landfills and adjacent territories using green plantations and a biological system based on an apparatus–biological complex for purification from microbiological contamination. The data obtained in our laboratory studies show that such apparatus–biological complexes can reduce the negative influence on the personnel and workers at operative points and on the inhabitants of adjacent territories by air purification.

The article describes the design of a digital model of an HPC system for processing data from the Super Charm-Tau factory electron-positron collider of the \"megascience\" class. This model is developed using the AGNES multiagent modeling platform. The model includes intelligent agents that mimic the behavior of the main subsystems of the supercomputer, such as a task scheduler, computing clusters, data storage system, etc. This model allows calculating the parameters of the computing system necessary for processing and storing the results of operation of the Super Charm-Tau factory after its commissioning.

The processes in polymer films based on polypropylene containing fluorinated additives during modification of films in corona discharge plasma are studied. The chemical composition, relief, adhesion and deformation properties of the film surface before and after modification in plasma were studied using the methods of X-ray photoelectron spectroscopy and atomic force microscopy. It has been established that in films under the influence of corona discharge plasma migration of the fluoropolymer additive to the surface occurs. In this case, the chemical composition and structure of the film changes, and local structures containing oxygen, fluorine and carbon atoms are formed on the surface. Local structures have an electrical resistance that is different from the electrical resistance of the surface of the original film. Plasma modification leads to an improvement in the elastic and adhesive properties of the polypropylene film surface.

A covering code, or a covering, is a set of codewords such that the union of balls centered at these codewords covers the entire space. As a rule, the problem consists in finding the minimum cardinality of a covering code. For the classical Hamming metric, the size of the smallest covering code of a fixed radius is known up to a constant factor. A similar result has recently been obtained for codes with insertions and for codes with deletions. In the present paper we study coverings of a space for the fixed length Levenshtein metric, i.e., for insertions and deletions. For and , we prove new lower and upper bounds on the minimum cardinality of a covering code, which differ by a constant factor only.

At the Unique Scientific Facility NEVOD (MEPhI), a large coordinate-tracking detector based on drift chambers for investigations of muon bundles generated by ultrahigh energy primary cosmic rays is being developed. One of the main characteristics of the bundle is muon multiplicity. Three methods of reconstruction of multiple events were investigated: the sequential search method, method of finding the straight line and method of histograms. The last method determines the number of tracks with the same zenith angle in the event. It is most suitable for the determination of muon multiplicity: because of a large distance to the point of generation of muons, their trajectories are quasiparallel. The paper presents results of application of three reconstruction methods to data from the experiment, and also first results of the detector operation.