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Evolutionary status of T Tauri stars

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Research in Astronomy and Astrophysics 2018年第8期18卷 103-110页

作者： olga Eretnova Alexander Dudorov physics Department Chelyabinsk State University

The problem of determining the masses and ages of T Tauri star （TTS） using their evolu- tionary status is discussed. We test four pre-main sequence evolutionary models using well determined observational parameters of 12 binary TTSs and two binary red dwarfs. It is shown that the masses derived using the tracks of all models are in good agreement with flhe masses obtained from the obser- vations of TTSs with masses M 〉 0.7 Me （mean error ε,- 10%）. Low-mass stars with M ≤ 0.7 M⊙ have significantly greater mean error; e - 50% for the tracks of Bressan et al. and Chen et al., and e - 30% for the other tracks. The isochrones of all tested evolutionary models diverge for stars with masses M ≤ 0.7 M⊙. The difference increases with the mass decrease and can reach 10% of Kelvin- Helmholtz time for stars with mass M = 0.2 Me. The ages of most of the considered TTSs are smaller than the Kelvin-Helmholtz time. This confirms their evolutionary status of being pre-main sequence stars.

关键词： stars pre-main sequence stars - stars binaries - Hertzsprung-Russell diagram

Dynamics and genesis of calcic accumulations in soils and sediments of the Argentinean pampa

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International Journal of Sediment Research 2015年第3期30卷 179-189页

作者： Alsu Kuznetsova olga Khokhlova Department of Renewable resources University of Alberta Edmonton Institute of physicochemical and Biological problems of Soil Science RAS puschino

Micromorphology of calcic accumulations(calcite,whewellite and gypsum) and geochemical indices were considered as indicators of genesis and evolution of pedogenic accumulations in soils and paleosediments of the Argentinean *** groups of separate and independent calcic accumulations were studied using scanning electron microscopy:(i) in situ Argiudolls,reflecting the current soil formation;(ii) in the layers of calcrete(locally named tosca).reflecting the past environments and conditions of these layers *** pedogenic gypsum accumulations in Argiudolls were described and possible ways of their formation were *** analyses of morphology of carbonate accumulations and geochemical indices in different horizons of Argiudolls and layers of tosca showed that the tosca is paleopedocomplex with complicated formation *** of current environment on tosca morphology is absent,so it is possible to use these pedofeatures for paleoreconstructions in further studying.

关键词： Carbonate accumulations Gypsum accumulations pedogenic rhizoliths Tosca

Mixed layer in the Sea of Japan:numerical simulation andlong-term data analysis

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Acta Oceanologica Sinica 2005年第1期24卷 76-85页

作者： TRUSENKOVA olga KHRApCHENKOV Fyodor ISHIDA Hajime V.I.Il'ichev pacific Oceanological Institute Russian Academy of Sciences Vladivostok 690041 RussiaV.I.Il'ichev Pacific Oceanological Institute Russian Academy of Sciences Vladivostok 690041 RussiaFaculty of Engineering Kanazawa University Kanazawa 920-8667 Japan

Seasonal variation and topography of the mixed layer in the Sea of Japan are studied by comparison of results from long-term observation data analysis and from numerical simulation with the MHI oceanic model (Shapiro. 1998. Marine Hydrophysical Journal, 6: 26-40). The data are retrieved from Oceanographic A tlas of the Bering Sea, Okhotsk Sea, and Japan/East Sea (Rostov, Rostov, Dmitrieva, et al. 2003. pacific Oceanography, 1(1):70-72). The simulated and long-term patterns are compared. An impact of surface buoyancy flux, wind, and convergence/divergence of surface currents upon the mixed layer in the Sea of Japan is analyzed.

关键词： numerical modeling circuktion of the Sea of Japan mixed layer depth seasonal variation spatial patterns

Current problems of the Diagnostics and Treatment of Sepsis and Burn Injuries: The Modified pathogenetic Concept

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International Journal of Clinical Medicine 2023年第1期14卷 20-33页

作者： olga Kovalenko Lesia Ostapiuk Anatoliy Voloshinovskii Bohomolets National Medical University Kyiv Ukraine pulmonary Health Centre Lviv Ukraine Ivan Franko National University Lviv Ukraine

Background: The deep understanding of pathogenesis is a key moment in the formation of the modern strategy of modern medicine. We conducted the thorough analysis of the microscopic processes occurring in the bodies of patients with purulent-septic complications. The modified pathogenetic concept of the diagnostic and treatment model of diseases with septic complications is presented. The obtained information about the mechanisms of origin and development of these diseases is fundamentally important for finding the modern effective methods of treating patients. The aim of the research is to modify treatment tactics for patients with sepsis and burn injuries based on the modified pathogenetic concept using modern diagnostics, i.e. the method of fluorescence spectroscopy (MFS) and biomarkers. Materials and Methods: The proposed modified pathogenetic concept of the diagnostic and treatment model of diseases with purulent-septic complications along with standard methods was used successfully for effective treatment of 15 patients with sepsis and 25 with burn injuries. Results: 3 main scenarios of behaviour of spectral-fluorescence characteristics of patients with sepsis are illustrated. Spectral-fluorescence markers of sepsis were studied, which are informative 24 to 48 hours before the appearance of obvious clinical and laboratory signs of significant changes in the general somatic status of patients. Conclusions: The proposed diagnostic and therapeutic approach is new and fundamentally important for diagnostics and monitoring of the process of treatment of patients with purulent-septic diseases and burn injuries. An in-depth understanding of the dynamics of septic complications and the corresponding changes of the main markers of these diseases during treatment is especially relevant. The use of infusion therapy with solutions of donor albumin as an effective pathogenetic treatment is scientifically justified.

关键词： purulent-Inflammatory Diseases Sepsis Modified pathogenetic Diagnostic and Treatment Model Method of Fluorescent Spectroscopy Biomarkers Albumin Infusion

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

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：量子论 Yang-Baxter方程 R矩阵规则性

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

Sex,but not age and bone mass index positively impact on the development of osteochondral micro-defects and the accompanying cellular alterations during osteoarthritis progression

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Chronic Diseases and Translational Medicine 2022年第1期8卷 41-50页

作者： Angelos Kaspiris Efstathios Chronopoulos Elias Vasiliadis Lubna Khaldi Dimitra Melissaridou Ilias D.Iliopoulos olga D.Sawidou Laboratory of Molecular pharmacology Division for Orthopaedic ResearchSchool of Health SciencesUniversity of PatrasPatrasGreece Second Department of Orthopaedic Surgery School of MedicineNational and Kapodistrian University of Athens"Konstantopoulio"General HospitalAthensGreece Third Department of Orthopaedic Surgery "KAT"General Hospital and Medical SchoolUniversity of AthensAthensGreece Department of pathology "Agios Savvas"Athens Cancer Hospital-NHSAthensGreece First Department of Orthopaedic Surgery School of MedicineNational and Kapodistrian University of Athens"ATTIKON"University General HospitalAthensGreece Department of Orthopaedic Surgery "Rion"University Hospital and Medical SchoolSchool of Health SciencesUniversity of PatrasPatrasGreece

Background:Osteoarthritis(ΟΑ)is characterized by cartilage breakdown and subchondral ***-fractures of the calcified tissues have been,also,detected,but their exact role has not been elucidated *** study was to examine the frequency of cracks during OA progression and to correlate them with the underlying cellular modifications and matrix metalloproteinase-2(MMp-2)expression using histological/immunohistological ***:Overall,20 patients and 3 controls(9 specimens per patient),aged 60-89 years,diagnosed with hip/knee OA were *** development of cracks was examined in 138 sections,whereas the expression of MMp-2 was examined in 69 additional ***:Based on Mankin score,three groups of OA severity were analyzed:Group I(mild)was constituted of sections with score 1-5 while Groups II(moderate)and III(severe)with score 6-7 and greater or equal to 8,*** characteristics did not reveal any association between the number of microdefects and age or body mass index(BMI).Cartilage micro-cracks were increased during moderate and severe OA,while bone cracks were increased during mild and severe *** knee OA,cartilage cracks were not correlated with Mankin score,whereas in hip OA they appeared association with severity *** cracks were positively correlated with matrix apoptotic osteocytes and osteoblastic cells,but not with ***-2 immunostaining was increasing by OA severity in the osteochondral ***,MMp-2 was expressed on the microcracks’wall mainly in Group ***:Our data displayed that bone cracks during primary OA stages,represent an early adaptative mechanism aiming to maintain cartilage *** of bone defects and concomitant increase of apoptotic osteocytes activated an abnormal remodeling due to osteoblastic activity,in which MMp-2 played a pivotal role,leading to subchondral sclerosis promoting further osteochondral deformities.

关键词： demographic characteristics matrix metalloproteinase-2 micro-cracks osteoarthritis