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Measurement of Electrical Resistance of Liquid Electrolytes and Materials Containing Them

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Journal of Electromagnetic Analysis and Applications 2020年第2期12卷 7-14页

作者： Kirill V. Dobrego Mikhail A. Chumachenko Olga V. Boiprav nikolay n grinchik Halina A. Pukhir Belarusian national Technical University Minsk Belarus Belarusian State University of Informatics and Radioelectronics Minsk Belarus A.V. Luikov Heat and Mass Transfer Institute of nAS of Belarus Minsk Belarus

Measurement of the electrical conductivity of electrolytes and heterogeneous materials containing them is accompanied by numerous physical and electrochemical processes, complicating measuring and interpretation of data. As a result, the measurement of the electrical conductivity of such a system is a difficult and not finally resolved problem. The new method of resistance measurement of the electrolytic systems is substantiated and tested on example of heterogeneous electrolytic system “lignin-calcium chloride water solution” in this article. The method is based on measurement of resistance of the electrolytic system at different voltages (DC) on the cell and the consequent approximation of the acquired data taking into consideration volume charges and potential barriers arising on the boarders of electrodes and electrolytic materials. Extrapolation of the resistance to the limiting small current lets one obtain a characteristic value of the active resistance of the electrolytic system. The method is technically simple, inexpensive and has several advantages compared to the methods based on AC measurements.

关键词： Electrolyte Conductivity Conductometry Resistance

Regularities of nanofocusing of the Electromagnetic Field of a Fractal Rough Surface

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Journal of Electromagnetic Analysis and Applications 2019年第8期11卷 117-133页

作者： nikolay n. grinchik Galina M. Zayats Olga V. Boiprav Kirill V. Dobrego Volha A. Prykhodzka A.V. Luikov Heat and Mass Transfer Institute of the national Academy of Sciences of Belarus Minsk Belarus Institute of Mathematics of the national Academy of Sciences of Belarus Minsk Belarus Belarusian State University of Informatics and Radioelectronics Minsk Belarus Belarusian national Technical University Minsk Belarus Belarusian State University Minsk Belarus

A consistent physical and mathematical model of the propagation of electromagnetic waves in an inhomogeneous medium with strong discontinuities of the electromagnetic field at the interface of two media, which is a rough surface, was developed. Mathematical modeling of rough surfaces and their profiles was carried out using fractal geometry, which allows us to display the topology of the object as close as possible to reality. For real heterogeneous rough structures, we have developed a through-counting method that takes into account the continuity of the total current at the interfaces of adjacent media, the effect of induced surface charge and surface current. This approach lets one avoid the necessity to set surface impedances depending on the structure of the field being determined and on the material properties.

关键词： nonstationary Broadening of the Spectral Line Fractal Roughness Surface Charge Surface Current Electromagnetic Wave Soliton-Like Electromagnetic Pulse

Ion-conducting Membranes Based on Bacterial Cellulose nanofibers Modified by Poly(sodium acrylate-co-2-acrylamido-2-methylpropanesulfonic acid)

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Chinese Journal of Polymer Science 2024年第3期42卷 333-343,I0007页

作者： Elizaveta V.Batishcheva nikolay n.Smirnov natalya V.Bobrova Maria P.Sokolova Michael A.Smirnov Institute of Macromolecular Compounds Russian Academy of SciencesBolshoy pr.31Saint Petersburg 199004Russia

Green method for preparation of ion-conducting membranes(ICM) based on bacterial cellulose nanofibers(CnF) modified by a copolymer of sodium acrylate and 2-acrylamido-2-methylpropanesulfonic acid was elaborated. FTIR and nMR data confirmed grafting of polyacrylate onto cellulose surface. Formation of porous structure of the ICM was controlled by SEM and AFM. The maximal ionic conductivity of the membranes reaches 1.5 and 3.1 mS·cm^(-1)(60 ℃ and 98% relative humidity) when they are saturated with water or H_2SO_4(1 mol·L^(-1)) electrolyte,respectively. Prepared ICM was tested as a separator in a symmetrical supercapacitor with electrodes based on polyaniline hydrogel. The assembled cell demonstrate ability to operate at high current density up to 100 A·g^(-1) maintaining specific capacitance 165 F·g^(-1). Maximal specific capacitance of 289 F·g^(-1) was achieved at current density 1 A·g^(-1). Retaining of 90% of initial capacitance after 10000 of charge-discharge cycles proves high electrochemical stability of prepared ICM.

关键词： Bacterial cellulose Ion conductivity Porous membrane Supercapacitor

Self-healable and Robust Film Based on Electroactive Polymer Brush as Electrode for Flexible Supercapacitor

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Chinese Journal of Polymer Science 2024年第8期42卷 1049-1059页

作者： Maria P.Sokolova Vitaly K.Vorobiov nikolay n.Smirnov Ivan S.Kuryndin natalya V.Bobrova Michael A.Smirnov Institute of Macromolecular Compounds Russian Academy of SciencesBolshoy pr.31Saint Petersburg 199004Russia

The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible *** this purpose,the electroconductive polymer brushes(EPB)was *** synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the *** films were prepared by casting of EPB solution with subsequent *** of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA *** was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.

关键词： Polymer brush Polyaniline Flexible supercapacitor Self-healing Electroconducting film

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超表面:塑造光子学的未来

Science Bulletin 2024年第11期69卷 1607-1611页

作者： nikolay L.Kazanskiy Svetlana n.Khonina Muhammad A.Butt Samara national Research University Samara 443086Russia

A metasurface, often abbreviated as MS, represents a thin, artificially crafted surface consisting of an assembly of subwavelength structures that interact with light in distinct manners. Typically,smaller than the wavelength of the light they engage with, these structures empower precise management of light properties such as polarization, phase, and amplitude.

关键词： precise abbreviated 光子学

The biosynthetic pathway of the hallucinogen mescaline and its heterologous reconstruction

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Molecular Plant 2024年第7期17卷 1129-1150页

作者： Paula Berman Luis Alejandro de Haro Ana-Rita Cavaco Sayantan Panda Younghui Dong nikolay Kuzmich Gabriel Lichtenstein Yoav Peleg Hila Harat Adam Jozwiaki Jianghua Cai Uwe Heinig Sagit Meir Ilana Rogachev Asaph Aharoni Department of Plant and Environmental Sciences Weizmann Institute of ScienceRehovot 7610001Israel Life Sciences Core Facilities Weizmann Institute of ScienceRehovot 7610001Israel The Maurice and Vivienne Wohl Institute for Drug Discovery Weizmann Institute of ScienceRehovot 7610001Israel Present address:Department of Cell and Metabolic Biology Leibniz Institute of Plant BiochemistryWeinberg 306120 Halle(Saale)Germany Department of Molecular&Cellular Pharmacology University of Miami Miler School of MedicineMiamiFL 33136USA Department of Botany and Plant Sciences University of California RiversideRiversideCA 92521USA Laboratory of Plant Hormones and Development Regulation of Chongqing School of Life SciencesChongqing UniversityChongqing 401331China

Mescaline,among the earliest identified natural hallucinogens,holds great potential in psychotherapy ***,despite the existence of a postulated biosynthetic pathway for more than half a century,the specific enzymes involved in this process are yet to be *** this study,we investigated the cactus Lophophora williamsii(Peyote),the largest known natural producer of the phenethylamine *** employed a multi-faceted approach,combining de novo whole-genome and transcriptome sequencing with comprehensive chemical profiling,enzymatic assays,molecular modeling,and pathway engineering for pathway *** identified four groups of enzymes responsible for the six catalytic steps in the mescaline biosynthetic pathway,and an n-methyltransferase enzyme that n-methylates all phenethylamine intermediates,likely modulating mescaline levels in ***,we reconstructed the mescaline biosynthetic pathway in both nicotiana benthamiana plants and yeast cells,providing novel insights into several challenges hindering complete heterologous mescaline *** together,our study opens up avenues for exploration of sustainable production approaches and responsible utilization of mescaline,safeguarding this valuable natural resource for future generations.

关键词： mescaline Lophophora williamsi Peyote biosynthetic pathway de novo genome sequencing mo-lecular modeling

Regularities of nanofocusing of the Electromagnetic Field of a Fractal Rough Surface

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3,6-Bis-β-Dicarbonylsubstituted Carbazoles Bearing n-Spacers and Their Eu(III) Complexes as Immunofluorescent Labelling Agents

Journal of Electromagnetic Analysis and Applications（电磁分析与应用期刊） 2019年第8期

作者： nikolay n.grinchik Galina M.Zayats Olga V.Boiprav Kirill V.Dobrego Volha A.Prykhodzka

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International Journal of Organic Chemistry 2024年第1期14卷 20-31页

作者： Dmitry E. Pugachev Georgy V. Zatonsky Tatyana S. Kostryukova Anna G. Shubina nikolay V. Vasiliev Department of Biological Microanalysis FGUP State Research Institute of Biological Engineering Moscow Russia Department of Theoretical and Applied Chemistry State University of Education Mytishchi Russia

new reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu3+ ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.

关键词： Fluorescence Immunoassay Fluorinated β-Diketones Carbazole Europium Complexes Streptavidin nanodispersions

Preface: Modern studies of variable stars

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Research in Astronomy and Astrophysics 2019年第3期19卷 1-2页

作者： nikolay n.Samus Sheng-Bang Qian Institute of Astronomy Russian Academy of Sciences Yunnan Observatories Chinese Academy of Sciences

In this Mini-Volume, seven papers written on the basis of talks selected from those presented at the scientific conference "Modern studies of variable stars," commemorating Prof. M. A. Svechnikov(1933–2011), are published. The conference covered a variety of variable-star topics; the papers in this Mini-Volume deal with close, mainly eclipsing, binaries, Herbig Be stars and stellar molecular masers, with an accent on stellar catalogs of different kinds. We briefly review the contents of these papers.

关键词： stars variable-stars binaries-ISM general