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Dispersion characteristics of complex electromechanical parameters of porous piezoceramics

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Journal of Advanced Dielectrics 2022年第2期12卷 14-18页

作者： i.A.Shvetsov M.A.Lugovaya M.G.Konstantinova P.A.Abramov e.i.petrova N.A.Shvetsova A.N.Rybyanets Southern Federal University No.194 Stachky AveRostov-on-Don 344090Russia

in this paper,the results of experimental study of dispersion characteristics of complex electromechanical parameters of ferroelectrically“hard”porous piezoceramics based on PZT composition were *** samples of porous piezoceramics were fabricated using a modified method of burning-out a pore *** complex constants of porous piezoceramics with relative porosity 16%and their frequency dependences were measured using the piezoelectric resonance analysis *** a result of experimental studies,regions of elastic,piezoelectric and electromechanical dispersion,characterized by anomalies in the frequency dependences of the imaginary and real parts of the complex constants of porous piezoelectric ceramics were *** was revealed also that the microstructural features of porous piezoceramics determine the character of frequency dependences of complex electromechanical parameters of porous piezoelectric *** conclu-sion,the microstructural and physical mechanisms of electromechanical losses and dispersion in porous piezoceramics were discussed.

关键词： Porous piezoceramics microstructure dispersion losses complex electromechanical constants

electrochemical synthesis of nanosized iron oxide-alumina system

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Journal of Advanced Ceramics 2016年第1期5卷 70-76页

作者： A.F.DReSVYANNiKOV i.O.GRiGORYeVA L.R.KHAYRULLiNA e.V.petrova Kazan National Research Technological University(KNRTU) Kazan 420015 Russia

An electrochemical method for the synthesis of complex dispersed oxide system Al2O3-Fe2O3, based on the combined aluminum and iron anodic dissolution in aqueous solution containing chloride ions, has been suggested. The phase composition and morphology of Al2O3-Fe2O3 dispersed precipitate have been investigated by means of X-ray fluorescence, X-ray diffraction (XRD), and scanning electron microscopy (SeM). The influence of the electrolysis mode on the characteristics of the synthesized oxide system has been shown. it is found that the direct current (DC) mode allows us to adjust the phase correlation in the precipitate and to obtain a particle size which is two or more times smaller than the particle size of the samples synthesized by means of the alternating current (AC).

关键词： alumina iron oxide mixed oxide system electrochemical synthesis nanoparticles

Kinetics and mechanism of natural wolframite interactions with sodium carbonate

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international Journal of Minerals,Metallurgy and Materials 2019年第11期26卷 1364-1371页

作者： evgeniy Nikolaevich Selivanov Kirill Vladimirovich Pikulin Lyudmila ivanovna Galkova Roza iosifovna Gulyaeva Sofia Aleksandrovna petrova institute of Metallurgy of the Ural Branch of the Russian Academy of Sciences

The kinetics and mechanism of natural wolframite interactions with sodium carbonate during air heating were studied.X-ray phase and X-ray microanalysis were used to establish that the initial monocrystalline wolframite consists of Fe0.5 Mn0.5 WO4 and Fe0.3 Mn0.7 *** thermal analysis showed that the interaction of wolframite with sodium carbonate begins above 450°C with the formation of tungstate,sodium ferrite,iron oxides,and *** experiments on sintering with the subsequent removal of water-soluble compounds(leaching)tracked the change in the structure of *** atomic ratio of Fe/Mn in wolframite does not change up to 600°C,and subsequently decreases to 0.2 during heating,which allows the mechanism of the process to be identified and indicates the greater reactivity of wolframites with an increased proportion of *** analysis with data processing using non-isothermal kinetics established that the interaction of wolframite with sodium carbonate in an air stream proceeds via a two-stage mechanism,wherein the first stage is limited by diffusion(activation energy,e=243 kJ/mol)and the second stage is limited by autocatalysis(activation energy,e=212 k J/mol)due to the formation of a Na2 WO4–Na2 CO3 eutectic.

关键词： wolframite structure sodium carbonate sintering thermal analysis kinetics

The forecast of fire impact on Pinus sylvestris renewal in southwestern Siberia

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Journal of Forestry Research 2021年第5期32卷 1911-1919页

作者： Stanislav NSannikov Nelly SSannikova irina Vpetrova Olga e.Cherepanova Botanical Garden of the Ural Branch of Russian Academy of Science 202a8 Marta St.Yekaterinburg 620144Russia

Simulation of fire impact on forest floor renewal in pine forests was based on predictions for 2100 by the Canadian Climate Centre for increase in temperatures of by4.5℃and total precipitation by 14%in the West Siberian pre-forest-steppes and empirical regression relationships between them and the degree of burnt forest floor,as well as amount of Pinus sylvestris *** was predicted that by 2100,pine regeneration on fire prone sites under the canopy of the dominant forest type will increase by 29-54%compared to the 1980 s but on adjacent open sites,regeneration will decrease twice as *** means that the regeneration potential and pine population stability in pre-forest-steppes will become as poor as it is today.

关键词： Fire Forecast Stability Population Mathematical model Seeds imitation model Undergrowth

Some Remarks to Numerical Solutions of the equations of Mathematical Physics

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American Journal of Computational Mathematics 2013年第3期3卷 205-210页

作者： Ludmila petrova Department of Computational Mathematics and Cybernetics Moscow State University Moscow Russia

The equations of mathematical physics, which describe some actual processes, are defined on manifolds (tangent, a companying or others) that are not integrable. The derivatives on such manifolds turn out to be inconsistent, i.e. they don’t form a differential. Therefore, the solutions to equations obtained in numerical modelling the derivatives on such manifolds are not functions. They will depend on the commutator made up by noncommutative mixed derivatives, and this fact relates to inconsistence of derivatives. (As it will be shown, such solutions have a physical meaning). The exact solutions (functions) to the equations of mathematical physics are obtained only in the case when the integrable structures are realized. So called generalized solutions are solutions on integrable structures. They are functions (depend only on variables) but are defined only on integrable structure, and, hence, the derivatives of functions or the functions themselves have discontinuities in the direction normal to integrable structure. in numerical simulation of the derivatives of differential equations, one cannot obtain such generalized solutions by continuous way, since this is connected with going from initial nonintegrable manifold to integrable structures. in numerical solving the equations of mathematical physics, it is possible to obtain exact solutions to differential equations only with the help of additional methods. The analysis of the solutions to differential equations with the help of skew-symmetric forms [1,2] can give certain recommendations for numerical solving the differential equations.

关键词： Two Systems of Reference Nonintegrable Manifolds and integrable Structures Solutions of Two Types Discrete Transitions Observable Formations

eight-Regularity of Types of Crop Capacity Structure of Winter Wheat

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Journal of Agricultural Science and Technology(B) 2011年第2期1卷 285-296页

作者： N. N. petrova The Byelarussian State Agricultuarl Academy Gorki City 213410 Russia

The elements of crop capacity structure of 13 summer characteristics in 33 winter wheat varieties, qualitative three-regularity and quantitative eight-regularity are investigated through the application of systematic approach. The principle of triadness applied in a language, in a genetic code and other codes is used, i.e. the logic homology is employed. The purpose are （1） to show the use of a systematic approach to the analysis of elements of crop capacity structure of winter wheat; （2） to analyze efficiency, the years of harvests and winter hardiness; （3） to find the way of selection and varieties assessment in terms of the elements efficiency. The quantitative compatibility as the highest with the sign ＂＋＂ and the lowest with the sign ＂-＂ in terms of elements efficiency gives eight types of crop capacities. The type of crop capacity structure ＂＋＋＋＂ can serve as a full （higher） measure of a variety adaptableness and optimality of technologies. The triad of three characteristics as a type-＂＋＋＋＂ in which the first sign is the quantity of ears （Qe）; the second is a quantity of grains （QG）; the third is the weight of grains （WG） creates the highest level of crop capacity.

关键词： Category of triadness eight-regularity crop capacity efficiency quantity of ears in 1 m^2 (Qe) quantity of grains in anear (QG) weight of 1 000 grains (WG) winter wheat.

Diagnostics of Sensory Ataxia in Patients with Sensory Predominant Chronic inflammatory Demyelinating Polyneuropathy from Republic of Sakha (Yakutia) and Krasnoyarsk Region

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Journal of Biosciences and Medicines 2016年第7期4卷 36-44页

作者： Т. Е. Popova N. А. Shnayder M. М. petrova А. А. Таppakhov T. Ya. Nikolaeva e. e. Konnikova Krasnoyarsk State Medical University Named after Professor V.F. Voino-Yasenetsky Krasnoyarsk Russia M.K. Ammosov North-eastern Federal University Yakutsk Russia

Materials and Methods: A group of healthy volunteers (24 people) and patients with SP-CiDP from Republic of Sakha (Yakutia) (42 people) and Krasnoyarsk region (87 people). Diagnostics Methods: Clinical neurologic, neurophysiological. Results: The results of stabilometry research of patients with SP-CiDP have revealed area expansion of pressure centre in phase eO and eC with deflection PC forward by anteropulsion type among patients with SP-CiDP from Republic of Sakha (Yakutia). Also in the Yakut group has been noted to have severer clinical course in comparison with inhabitants of Krasnoyarsk region. Conclusion: The method of computer stabilometry allows estimating objectively presence and degree of manifestation of sensitive ataxia in patients with SP-CiDP.

关键词： Sensory Predominant Chronic inflammatory Demyelinating Polyneuropathy (SP-CiDP) Diagnostics Sensory Ataxia Stabilometry

Telbivudine vs tenofovir in hepatitis B e antigen-negative chronic hepatitis B patients: OPTiMA roadmap study

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World Journal of Hepatology 2016年第32期8卷 1402-1413页

作者： Zahari Krastev Diana petrova iskren Kotzev Mustafa Kemal Celen Meryl Mendelson Richa Chandra Priti Pandey Kamal Hamed Clinic of Gastroenterology St.Ivan Rilsky University HospitalMedical University Department of Gastroenterology University Hospital Alexandrovska Clinic of Hepatogastroenterology University Hospital St Marina infectious Disease Clinic Dicle University Novartis Pharmaceuticals Corporation East Hanover Novartis Healthcare Pvt. Ltd.

AiMTo make efficacy and safety comparison of telbivudine-raodmap and tenofovir-roadmap in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. MeTHODSThis was the first prospective, randomised, two-arm, open-label, non-inferiority study in HBeAg-negative CHB patients that compared telbivudine and tenofovir administered as per roadmap concept. Patients were treated up to 24 wk and, depending on virologic response, continued the same therapy or received add-on therapy up to 104 wk. eligible patients received an additional 52 wk of treatment in the extension period (i.e., up to 156 wk). Patients who developed virologic breakthrough (VB) while on monotherapy also received add-on therapy. The primary efficacy endpoint was the rate of patients achieving hepatitis B virus (HBV) DNA ReSULTSA total of 241 patients were randomised. Non-inferiority of telbivudine arm to tenofovir arm was demonstrated at week 52 (± 7 d window), with over 91% of patients in each treatment arm achieving HBV DNA level CONCLUSiONefficacy was shown for both telbivudine-roadmap and tenofovir-roadmap regimens in HBeAg-negative CHB patients over 156 wk. Telbivudine arm was associated with renal improvement.

关键词： Chronic hepatitis B Glomerular filtration rate Telbivudine Tenofovir Roadmap concept

enhanced potato tuber penetration of carboxin via ultradeformable liposomes

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Food Bioscience 2022年第6期50卷 201-209页

作者： Leysan A.Vasileva Gulnara A.Gaynanova irek R.Nizameev Anna A.petrova Marsil K.Kadirov Tatyana A.Gorshkova Lucia Ya.Zakharova Arbuzov institute of Organic and Physical Chemistry FRC Kazan Scientific Center of RAS8 Arbuzov str.Kazan420088Russian Federation Kazan institute of Biochemistry and Biophysics FRC Kazan Scientific Center of RAS2/31 LobachevskyKazan420111Russian Federation

For the first time,a nanoformulated fungicide carboxin was obtained to solve the problem of infection of potato tubers with fungi *** of carboxin in ultra-deformable liposomes protects it from degradation by sunlight,increases solubility in water and penetration through potato *** fluorescent probes,rhodamine B and fluorescein,were used for optimization of original composition and for visualization of the transfersome localization in potato tubers,*** was encapsulated in lipid formulations with further evaluation of encapsulation efficiency,substrate release rate in vitro,and penetration through the Strat-M®membrane using Franz *** fluorescent microscopy,it was revealed that transfersomes penetrate through the periderm and enter cortex of potato *** the extraction it was shown that potato tubers weighing 100 g included 32 mg of carboxin after the transfersome *** inclusion of carboxin in transfersomes made it possible to increase the maximum concentration of carboxin in water from 0.57 mmol L−1 to 2.8–3.8 mmol L−1,i.e.,5–7 times.

关键词： Transfersomes Tween 20 Carboxin Adjuvant Potato tuber Franz cell