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Biogenic Amorphous Silica as Filler for Elastomers

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Journal of Renewable Materials 2018年第4期6卷 402-412页

作者： nikolay Dishovsky Petrunka Malinova Ivan Uzunov University of Chemical Technology and Metallurgy-Sofia 8 St.Kliment Ohridski Blv.1756 SofiaBulgaria Institute of General and Inorganic Chemistry Bulgarian Academy of SciencesAcad.G.Bonchev Str.bl.111113 SofiaBulgaria

Natural products from agricultural wastes are finding importance in the polymer industry due to their many advantages such as being lightweight,low cost and environmentally *** the present study the potential of the two types of rice husk ash(RHA)prepared under different conditions as fillers in natural rubber-based elastomer composites was *** fillers were prepared by rice husks incineration and characterized by means of X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM),Brunauer-Emmett-Teller(BET)specific surface area,Hg-porosimetry and *** evaluation involved determining the vulcanization characteristics of the compounds and their physical and mechanical characteristics,resistance to thermal aging as well as the dynamic properties of the vulcanizates containing *** has been found that the ash from rice husk has good potential as filler in elastomers,especially as a substitute for synthetic commercially available *** improves the grip on ice and snow better than standard silica and may be used in formulations for shoe soles used for winter sports,extreme hiking footwear,ski boot soles,winter tire protectors,*** quality depends on the conditions under which rice husk is *** is recommended to run the process at a temperature not higher than 800°*** particular,cases in which the vulcanizates contain biogenic silica have very interesting characteristics like improved modulus at 300%of elongation,lower residual elongation,higher mechanical loss angle tangent at 0°C and lower at 60°C,and are superior to those of the vulcanizates containing commercially available filler Ultrasil?7000 GR.

关键词： Rice husk ash fillers natural rubber mechanical characteristics dynamic properties

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

Tin phosphide-carbon composite as a high-performance anode active material for sodium-ion batteries with high energy density

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Journal of Energy Chemistry 2022年第1期31卷 463-474,I0012页

作者： Zhiqiang Hao nikolay Dimov Jeng-Kuei Chang Shigeto Okada Department of Chemical Engineering Faculty of EngineeringKyushu UniversityFukuoka 816-8580Japan Institute for Materials Chemistry and Engineering Kyushu UniversityFukuoka 816-8580Japan Department of Materials Science and Engineering Chiao Tung University.1001 University RoadHsinchu 30010.TaiwanChina

Tin phosphide(Sn_(4)P_(3))is a promising anode material for sodium-ion batteries because of its relatively large theoretical capacity,appropriate Na^(+) alloying potential,and good cyclic ***,the Sn_(4)P_(3) embedded into a carbon matrix with good rate performance and long cycle life is *** Sn_(4)P_(3)-C composite exhibits excellent rate performance(540 mAh g^(-1) at 5 A g^(-1))and the highest reversible capacity(844 mAh g^(-1) at 0.5 A ^(g-1))among Sn4P3-based anodes reported so *** reversible capacity is as high as 705 mAh g^(-1) even after 100 cycles at 0.5 A g^(-1).Besides,its initial Coulomb efficiency can reach 85.6%,with the average Coulomb efficiency exceeding 99.75%from the 3rd to 100th ***_(2)C_(6)O_(6) is firstly used as a cathode when Sn_(4)P_(3) acts as anode,and the Na-Sn_(4)P_(3)-C//Na_(2)C_(6)O_(6) full cell shows excellent electrochemical *** results demonstrate that the Sn_(4)P_(3)-C composite prepared in this work displays high-rate capability and superior cyclic performance,and thus is a potential anode for sodium ion batteries.

关键词： Tin phosphide Sodium-ion batteries Sn_(4)P_(3) Conversion Alloy

Mechanisms of cast structure and stressed state formation in Hadfield steel

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China Foundry 2016年第6期13卷 433-442页

作者： Dmitri Gorlenko Konstantin Vdovin nikolay Feoktistov Nosov Magnitogorsk State Technical University Magnitogorsk Russia

The paper describes the investigation of mechanisms of cast structure formation in Hadfield steel depending on the changes in the cooling rate of a casting in the following two temperature ranges： crystallization temperature（1,200-1,390 ℃） and the temperature of excessive phase separation（560-790 ℃）. Changes in the cooling rate of the crystallization temperature range from 1.1 to 25.0 ℃s^-1 result in the reduction of the average size of austenite grains from 266 to 131 μm. At the same time, the magnitude of developing shrinkage stresses changes from ＋195 to 0 MPa. When the cooling rate is higher than 16 ℃^-1, no shrinkage stresses are formed in the casting. Changes in the cooling rate of the casting in the temperature range of the excessive phase separation influence the number of phases, their morphology and chemical composition, the values of phase stresses, and the possibility of martensitic transformation. Changing in the cooling rate from 0.24 to 5.46 ℃^-1 results in the decrease of the amount of the excessive phase from 14.8% to 2.1%, which is composed of eutectic and carbides depending on the cooling rate, their quantitative ratio and morphology change. Such changes in the microstructure are reflected on the changes of value of developing phase stresses. When the cooling rate is 0.24 ℃^-1, it is ＋100 MPa, while the increase of the cooling rate to 1.4 ℃^-1 results in the decrease of tensile stresses to 0 MPa and their qualitative stresses change to compressive ones. Further increase of the cooling rate results in the increase of the value of compressive stresses. When the cooling rate is 5.5 ℃^-1, their value reaches-92 MPa. Martensite forming in the structure of Hadfield steel is possible if the cooling rate of the casting in the range of excessive phase separation is less than 0.25 ℃^-1.

关键词： Hadfield steel crystallization austenite excessive phase stress

A new species of the genus Micryletta(Anura,Microhylidae) from Hainan Island, China

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Zoological Research 2021年第2期42卷 234-240页

作者： Jian-Huan Yang nikolay A.Poyarkov Kadoorie Conservation China Kadoorie Farm and Botanic GardenTai PoHong Kong SARChina Faculty of Biology Department of Vertebrate ZoologyMoscow State UniversityMoscow 119234Russia Laboratory of Tropical Ecology Joint Russian-Vietnamese Tropical Research and Technological CenterHanoiVietnam

DEAR EDITOR,We report on a new amphibian species of the genus Micryletta from Hainan Island, China, based on morphological and molecular analyses. The new species, Micryletta immaculata sp. nov., is diagnosed by a combination of the following morphological characters: medium-sized within genus(SVL23.3–24. mm in males, n=3;27.7–30.1 mm in females, n=2).

关键词： nov. Island new

Influence of non-equilibrium reactions on the optimization of aerothrust aeroassisted maneuver with orbital change

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Chinese Journal of Aeronautics 2020年第8期33卷 2133-2145页

作者： nikolay AELISOV Sergey AISHKOV Igor ALOMAKA Valentin GSHAKHOV Department of Space Engineering Samara National Research UniversitySamara 443086Russia Inter-University Department of Space Research Samara National Research UniversitySamara 443086Russia Department of Aircraft Construction and Design Samara National Research UniversitySamara 443086Russia

The spaceplane is perspective vehicle due to wide maneuverability in comparison with a space capsule. Its maneuverability is expressed by the larger flight range and also by a possibility to rotate orbital inclination in the atmosphere by the aerodynamic and thrust forces. Orbital plane atmospheric rotation maneuvers can significantly reduce fuel costs compared to rocket-dynamic non-coplanar maneuver. However, this maneuver occurs at Mach numbers about 25, and such velocities lead to non-equilibrium chemical reactions in the shock wave. Such reactions change a physicochemical air property, and it affects aerodynamic coefficients. This paper investigates the influence of non-equilibrium reactions on the aerothrust aeroassisted maneuver with orbital *** approach is to solve an optimization problem using the differential evolution algorithm with a temperature limitation. The spaceplane aerodynamic coefficients are determined by the numerical solution of the Reynolds-averaged Navier-Stokes equations. The aerodynamic calculations are conducted for the cases of perfect and non-equilibrium gases. A comparison of optimal trajectories,control laws, and fuel costs is made between models of perfect and non-equilibrium gases. The effect of a chemically reacting gas on the finite parameters is also evaluated using control laws obtained for a perfect gas.

关键词： Atmospheric entry Boundary value problem Computational fluid dynamics Differential evolution Flight mechanics Non-equilibrium flow Spaceplane

A new insight into the nature of seasonal variations in coordinate time series of GPS sites located near active faults

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Frontiers of Earth Science 2016年第3期10卷 560-569页

作者： Sergey V. TROFIMENKO Victor G. BYKOV nikolay V. SHESTAKOV nikolay N. GRIB Hiroaki TAKAHASHI Institute of Tectonics and Geophysics Far Eastern Branch Russian Academy of Sciences Khabarovsk 680000 Russia North-Eastern Federal University Neryungri 678960 the Republic of Sakha (Yakutia) Russia Institute for Applied Mathematics Far Eastern Branch Russian Academy of Sciences Vladivostok 690041 Russia Far Eastern Federal University Vladivostok 690041 Russia Institute of Seismology and Volcanology Graduate School of Science Hokkaido University Sapporo 060-0810 Japan

This study provides new insights into the nature of seasonal variations in coordinate time series of GPS sites located near active faults and methods of their modeling. Monthly averaged coordinate time series were analyzed for several pairs of collocated GPS sites situated near the active fault intersection area, in close proximity to the central part of the northern boundary of the Amurian plate and the vicinity of the San Andreas Fault zone. It is concluded that the observed seasonal variations are best described by a breather function which is one of the solutions of the well-known sine-Gordon equation. The obtained results suggest that, in this case, the source of seasonal variations may be caused by the appearance of solitary strain waves in the fault intersection system, which may be qualitatively treated as standing waves of compression-extension of the geological medium. Based on statistical testing, the limits of applicability of the suggested model have been established.

关键词： space geodetic surveys oscillatory move-ments of crustal blocks seasonal variations Amurianmicroplate

Current approaches to the management of patients with cirrhotic ascites

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World Journal of Gastroenterology 2019年第28期25卷 3738-3752页

作者： Dmitry Victorovich Garbuzenko nikolay Olegovich Arefyev Department of Faculty Surgery South Ural State Medical University Chelyabinsk 454092 Russia Department of Pathological Anatomy and Forensic Medicine South Ural State Medical University Chelyabinsk 454092 Russia

This review describes current approaches to the management of patients with cirrhotic ascites in relation to the severity of its clinical manifestations. The PubMed database, the Google Scholar retrieval system, the Cochrane Database of Systematic Reviews, and the reference lists from related articles were used to search for relevant publications. Articles corresponding to the aim of the review were selected for 1991-2018 using the keywords:“liver cirrhosis,”“portal hypertension,”“ascites,”“pathogenesis,”“diagnostics,” and “treatment.” Uncomplicated and refractory ascites in patients with cirrhosis were the inclusion criteria. The literature analysis has shown that despite the achievements of modern hepatology, the presence of ascites is associated with poor prognosis and high mortality. The key to successful management of patients with ascites may be the stratification of the risk of an adverse outcome and personalized therapy. Pathogenetically based approach to the choice of pharmacotherapy and optimization of minimally invasive methods of treatment may improve the quality of life and increase the survival rate of this category of patients.

关键词： Liver cirrhosis Ascites Diuretics Large volume paracentesis Peritoneovenous shunting Transjugular intrahepatic portosystemic shunting

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