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Control of chaotic oscillations of a satellite

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Applied Mathematics and Mechanics(English Edition) 2007年第7期28卷 893-900页

作者： Alexey Bobtsov Nikolay Nikolaev olga Slita Department of Control Systems and informatics Saint-Petersburg State University of Information Technologies Mechanics and OpticsKronverksky Ave.49Saint-Petersburg197101Russia

Analytical conditions and practical methods of their realization are proposed to solve a problem of a command signal tracking for a nonlinear disturbed system. Nonlinear disturbed plants consisting of linear dynamic block and nonlinear block in feedback are considered. Nonlinear part of the plant and disturbance are unknown and bounded. The paper illustrates a possibility of applications of proposed algorithms to control libration angle of satellite.

关键词： adaptive control chaotic behaviour satellite control nonlinear stabilization nonlinear control output control

influence of polyolefin fibers on the strength and deformability properties of road pavement concrete

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第4期6卷 407-417页

作者： olga Smirnova Alexey Kharitonov Yuriy Belentsov Department of Constructing Mining Enterprises and Underground Structures Saint-Petersburg Mining UniversitySaint Petersburg 199106Russia Department of Technology of Building Materials and Metrology Saint-Petersburg State University of Architecture and Civil EngineeringSaint Petersburg 190005Russia Department of Building Materials and Technologies Emperor Alexander I St.Petersburg State Transport UniversitySaint Petersburg 190031Russia

influence of the type and quantity of polyolefin fibers on the strength properties(compression strength, tensile strength in bending, strength in uniaxial tension), the deformation properties(elastic modulus, Poisson’s coefficient) and the abrasion resistance of cement concrete with water-to-cement ratio within 0.31 e0.55 were stated in the *** ways of fibers introduction into fresh concrete were investigated. it was shown that the fibers introduction method and procedure of mixing are the ways to improve the fibers uniform distribution in fresh concrete. The increase of the bending tensile strength and the uniaxial tensile strength of concrete with fibers reinforcement in comparison with the reference concrete was observed with the water-to-cement ratio decrease. The increase of uniaxial tensile strength at age of 28 days for concrete with macrofibers in amount of4.5 kg/m^3 was 23% and 29%;for macrofibers in quantity of 3 kg/m^3 was 19% and 26% with water-cement ratio equal to 0.49 and 0.31, respectively. The maximum reduction of abrasion in the range of 7.5%e10% was observed in concrete with water-to-cement ratio within0.44 e0.55 for all investigated types of fibers. The influence of fibers on the concrete abrasion with lower W/C ratio was negligible. The results can contribute to the rational use of modified polyolefin fibers in road pavement concrete.

关键词： Road pavement concrete Polyolefin fibers Strength Elastic modulus Abrasion Water-to-cement ratio

GLOBAL EXiSTENCE,UNiQUENESS,AND STABiLiTY FOR A NONLiNEAR HYPERBOLiC-PARABOLiC PROBLEM iN PULSE COMBUSTiON

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Acta Mathematica Scientia 2012年第1期32卷 41-74页

作者： olga Terlyga Hamid Bellout Frederick Bloom Fermi National Laboratory Department of Mathematical Sciences Northern Illinois University

A global existence theorem is established for an initial-boundary value prob- lem, with time-dependent boundary data, arising in a lumped parameter model of pulse combustion; the model in question gives rise to a nonlinear mixed hyperbolic-parabolic sys- tem. Using results previously established for the associated linear problem, a fixed point argument is employed to prove local existence for a regularized version of the nonlinear problem with artificial viscosity. Appropriate a-priori estimates are then derived which imply that the local existence result can be extended to a global existence theorem for the regularized problem. Finally, a different set of a priori estimates is generated which allows for taking the limit as the artificial viscosity parameter converges to zero; the corresponding solution of the regularized problem is then proven to converge to the unique solution of the initial-boundary value problem for the original, nonlinear, hyperbolic-parabolic system.

关键词： pulse combustion hyperbolic-parabolic system global existence regularity

Quantum Yang-Baxter equation and constant R-matrix over Grassmann algebra

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第10期6卷 1065-1079页

作者： DUPLiJ Steven KOTULSKA olga SADOVNiKOV Alexander Department of Physics and Technology V.N. Karazin Kharkov National University Svoboda Sq. 4 Kharkov 61077 UkraineDepartment of Physics and Technology V.N. Karazin Kharkov National University Svoboda Sq. 4 Kharkov 61077 UkraineDepartment of Physics and Technology V.N. Karazin Kharkov National University Svoboda Sq. 4 Kharkov 61077 Ukraine

Constant solutions to Yang-Baxter equation are investigated over Grassmann algebra for the case of 6-vertex R-matrix. The general classification of all possible solutions over Grassmann algebra and particular cases with 2,3,4 generators are studied. As distinct from the standard case, when R-matrix over number field can have a maximum 5 nonvanishing elements, we obtain over Grassmann algebra a set of new full 6-vertex solutions. The solutions leading to regular R-matrices which appear in weak Hopf algebras are considered.

关键词： Constant solution Grassmann algebra Regularity R-matrix

The influence of Poly(Vinyl Alcohol)on Oil Release Behavior of Polylactide-Based Composites Filled with Linseed Cake

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Journal of Renewable Materials 2020年第4期8卷 347-363页

作者： olga Mysiukiewicz Mateusz Barczewski Joanna Szulc Division of Polymer Processing Institute of Material TechnologyPoznan University of TechnologyPoznan61-138Poland Departament of Food industry Technology and Engineering Faculty of Chemical Technology and EngineeringUTP University of Science and TechnologyBydgoszcz85-326Poland

in order to limit the negative impact of industry on natural environment,ecological alternatives to conventional polymers are being *** of the most popular“green”polymers is polylactide,which can also be successfully applied as a matrix of *** application of ground linseed cake as a filler for polylactide-based composites is in line with the idea of Circular Economy,and moreover it provides a modifying effect on the polymer by increasing its crystallinity and reducing its *** effect is caused by the presence of linseed oil which can be released to the polymeric matrix in a non-controlled *** order to control the miscibility of the oil and the polymer,we modified the filler particles with poly(vinyl alcohol)before introducing it to the *** concluded that poly(vinyl alcohol),which does not mix with oil,encapsulated the active ingredients inside the filler *** evaluated the mechanical properties of the composites containing 5,10,20 and 30 wt%of the filler in a static tensile stress and by means of dynamic mechanical thermal *** and thermal properties were tested using differential scanning calorimetry as well as thermogravimetric ***’microstructure was evaluated by Scanning Electron *** was found that modifying the oil-rich filler with poly(vinyl alcohol)helps to reduce its release to the matrix and thus limits the plasticizing effect of linseed *** result was in accordance with our hypothesis.

关键词： Polylactide poly(vinyl alcohol) waste filler oil release

Performance of low temperature Microbial Fuel Cells(MFCs)catalyzed by mixed bacterial consortia

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Journal of Environmental Sciences 2017年第2期29卷 284-292页

作者： olga Tkach Thangavel Sangeetha Spiridonova Maria Aijie Wang State Key Laboratory of Urban Water Resources and Enuironment(SKLUWRE) Harbin Institute of TechnologyHarbin 150090China. Key Laboratory of Environmental Biotechnology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Krasnoyarsk State institution of Railway Vehicles Krasnoyarsk 660028Russia

Microbial Fuel Cells（MFCs） are a promising technology for treating wastewater in a sustainable manner. in potential applications, low temperatures substantially reduce MFC performance. To better understand the effect of temperature and particularly how bioanodes respond to changes in temperature, we investigated the current generation of mixed-culture and pure-culture MFCs at two low temperatures, 10°C and 5°C. The results implied that the mixed-culture MFC sustainably performed better than the pure-culture（Shewanella） MFC at 10°C, but the electrogenic activity of anodic bacteria was substantially reduced at the lower temperature of 5°C. At 10°C, the maximum output voltage generated with the mixed-culture was 540–560 m V, which was 10%–15% higher than that of Shewanella MFCs. The maximum power density reached 465.3 ± 5.8 m W/m^2 for the mixed-culture at10°C, while only 68.7 ± 3.7 m W/m^2 was achieved with the pure-culture. it was shown that the anodic biofilm of the mixed-culture MFC had a lower overpotential and resistance than the pure-culture MFC. Phylogenetic analysis disclosed the prevalence of Geobacter and Pseudomonas rather than Shewanella in the mixed-culture anodic biofilm, which mitigated the increase of resistance or overpotential at low temperatures.

关键词： Microbial fuel cell Psychrophilic bacteria Shewanella Low temperature Bioelectrochemical

Scheimpflug imaging of the Anterior Eye Segment during Standardized Accommodation Stimulation in Patients with Emmetropia, Myopia and Hypermetropia

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Open Journal of Ophthalmology 2023年第1期13卷 73-82页

作者： olga i. Rozanova irkutsk Branch of S. Fyodorov “Eye Microsurgery” Federal State institution of Ministry of Health of Russian Federation Ir-kutsk Russia

Understanding of the biomechanics of the accommodative apparatus in the eyes with different refraction is important for solving the problems of theoretical and practical ophthalmology. Purpose: To determine the changes of anterior eye segment dimensions during accommodation response in normal eyes and in patients with myopia, hypermetropia. Methods and Material: 116 eyes (56 patients aged from 18 to 30 years, refraction from -2.0 to + 2.0 D) were examined. All the patients underwent a full ophthalmological examination. The ocular anterior segment was imaged using a rotational Scheimpflug camera Pentacam HR (Oculus, Wetzlar, Germany) under non- and 3.0 D of accommodative demands. The statistical data were represented as the mean value ± standard deviation (M ± SD). The Shapiro-Wilk test was used to assess the normality distribution. Wilcoxon test was used for comparison. Results: Results showed an increase in the optical density of the crystalline lens, a pupil diameter decrease and changing of the iris profile during accommodation in all patients. An increase in the total corneal aberrations and decrease in the corneal spherical aberration were revealed only in emmetropic eyes. Conclusions: The accommodative response is a multicomponent process. Scheimpflug visualization revealed the differences in the accommodative response in normal and ametropic eyes.

关键词： Eye Accommodation Scheimpflug imaging Pupil Response

A simple method to model the reduced environment of lake bottom sapropel formation

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Chinese Journal of Oceanology and Limnology 2017年第4期35卷 956-966页

作者： olga L.GASKOVA Vera D.STRAKHOVENKO Nadezhda i.ERMOLAEVA Eugene Yu.ZARUBiNA Ekaterina A.OVDiNA V.S.Sobolev institute of Geology and Mineralogy Siberian Branch of the Russian Academy of Sciences Novosibirsk State University institute for Water and Environmental Problems Siberian Branch of the Russian Academy of Sciences

The Kambala and Barchin brackish lakes （Baraba steppe, southern West Siberia） contain an organic-rich sapropel layer that was formed in oxygen-depleted waters. We measured the bulk sediment elemental composition, the water chemistry and determined the mineralogical composition and predominant biota species （Diatoms and Cyanobacteria in phytoplankton community respectively） in the lakes. The result indicates that the first lake has a siliceous type of sapropel and the second a carbonaceous one. A computer thermodynamic model was developed for chemical interaction in water-bottom sediment systems of the Kambala and Barchin Lakes. The surface sodium bicarbonate waters are supersaturated with respect to calcite, magnesite （or low Mg-calcite）, quartz and chlorite with minor strontianite, apatite and goethite （pH 8.9-9.3, Eh 0.3 V）. Nevertheless, it is shown that during sapropel deposition, deep silt waters should be anoxic （Eh〈0 V）. The virtual component CH20 has been used to create an anoxic environment suitable for pyrite formation due to the biotic community impact and abiotic reduction. Thermodynamic calculation has shown that silt water is not necessarily euxinic （anoxic and sulfidic）. Depending on Eh, sulfate sulfur can dominate in solution, causing the formation of gypsum together with pyrite. An attempt was made to find a reason for solution supersaturation with respect to Ca and Mg ions due to their complexation with humic acids.

关键词： brackish lakes sapropel sediments mineral composition silica calcite thermodynamic calculations

Expansion of Juniperus sibirica *** a response to climate change and associated effect on mountain tundra vegetation in the Northern Urals

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Journal of Mountain Science 2020年第10期17卷 2339-2353页

作者： Andrey A.GRiGORiEV Yulia V.SHALAUMOVA olga V.EROKHiNA Svetlana Yu.SOKOVNiNA Elizaveta i.VATOLiNA Martin WiLMKiNG institute of Plant and Animal Ecology UB RAS Laboratory of Geoinformation TechnologyEkaterinburgRussia institute of industrial Ecology UB RAS Laboratory of Mathematical Modeling in Ecology and MedicineEkaterinburgRussia institute of Plant and Animal Ecology UB RAS Laboratory of Vegetation and Mycobiota BiodiversityEkaterinburgRussia institute of Plant and Animal Ecology UB RAS Laboratory of Dynamics of Arctic EcosystemsLabytnangiRussia Department of Forest Taxation and Forest Management Institute of Forest and Nature ManagementUral state Forest Engineering UniversityEkaterinburgRussia institute for Botany and Landscape Ecology Greifswald UniversityGreifswaldGermany

Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently *** studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern Ural mountains,*** structure analysis of the dominant shrub Juniperus sibirica *** to support ongoing upslope advance of shrubs,a process particularly active in the second half of the 20 th *** found a close connection between the expansion of shrub vegetation and the general change in climatic conditions of the cold season(months with mean airtemperature below 0°Сfrom November to March).in general,the greatest influence on the distribution of *** is exerted by the climate conditions of the beginning(November-January)and the end(March)of the cold *** increasing elevation,the correlation coefficients between the establishment of *** shrubs and the precipitation of the beginning of the cold season increased,and reached maximum values at the top elevation level of the study ***,the upwards shift of *** into typical mountain tundra does not lead to changes in the ecological structure of vegetation at this stage,but simply a decrease in the area of mountain tundra.

关键词： Juniperus sibirica Expansion Tundra Vegetation Plant communities Climate changes Northern Ural mountains