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

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

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Glial decline and loss of homeostatic support rather than inflammation defines cognitive aging

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Neural Regeneration Research 2022年第3期17卷 565-566页

作者： Alexei Verkhratsky Natalia Lazareva alexey Semyanov Faculty of Biology Medicine and HealthThe University of ManchesterManchesterUK Achucarro Center for Neuroscience IKERBASQUEBasque Foundation for ScienceBilbaoDepartment of NeurosciencesUniversity of the Basque Country UPV/EHU and CIBERNEDLeioaSpain Sechenov First Moscow State Medical University MoscowRussia Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of SciencesFaculty of BiologyMoscow State UniversityMoscowRussia

The preservation of cognitive longevity and arresting the pandemic of senile dementia engulfing the modern world is arguably the major challenge faced by biomedical research in the 21st *** is the leading risk factor for neurodegenerative diseases and vascular dementia,and yet there is a clear distinction between physiological and pathological brain aging.

关键词： inflammation senile aging

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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

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The evolution of eccentricity in the eclipsing binary system AS Camelopardalis

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Research in Astronomy and Astrophysics 2018年第1期18卷 113-118页

作者： Valentina Kozyreva Anatoly Kusakin alexey Bogomazov M.V.Lomonosov Moscow State University P.K.Sternberg Astronomical Institute National Space Agency Fesenkov Astrophysical Institute

In 2002,2004 and 2017 we conducted high precision CCD photometry observations of the eclipsing binary system AS *** analysis of the light curves from 1967 to 2017（our data ＋ data from the literature） we obtained photometric elements of the system and found a change in the system＇s orbital eccentricity of ？e = 0.03 ± *** change can indicate that there is a third companion in the system in a highly inclined orbit with respect to the orbital plane of the central binary,and its gravitational influence may cause the discrepancy between observed and theoretical apsidal motion rates of AS Cam.

关键词： binaries:close binaries:eclipsing stars:individual(AS Cam)

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Assessment of the Design Displacement Values at Seismic Fault Crossings and of Their Excess Probability

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Journal of Mountain Science 2011年第2期8卷 228-233页

作者： STROM Alexander IVASCHENKO alexey KOZHURIN Andrey Institute of Geospheres Dynamics of Russian Academy of Sciences Institute of Oceanology of Russian Academy of Sciences Geological Institute of Russian Academy of Sciences

Line structures such as pipelines that cross active faults should be designed to retain leak-tightness if the design displacement (Ddesign) occurs. Principal approaches to the Ddesign and rupture kinematics assessment are described. They are based on relationships between earthquake magnitude, rupture length and displacement, and on the detailed field data on a specific fault that crosses the pipeline route. Since the future offset at the crossing may exceed the design value, the probability of a displacement occurrence where the safety of the structure can not be ensured should be estimated. Assessment method on such event probability is described and exemplified through active fault studies carried out at several pipeline projects in Russia.

关键词： Active Fault Surface Rupture Design Displacement Pipeline Sakhalin Island

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Evaluation of opening of fractures in the Logovskoye carbonate reservoir, Perm Krai, Russia

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Petroleum Research 2021年第2期6卷 137-143页

作者： Dmitriy A.Martyushev alexey Yurikov Department of Oil and Gas Technologies Perm National Research Polytechnic UniversityPerm614990Russia WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerth6151Australia

The development of naturally fractured carbonate reservoirs is extremely challenging. Such reservoirshave a dual pore structure consisting of low-permeable matrix with large pore volume and highpermeable fractures constituting main paths for fluid flow. Productivity of wells drilled in such formations tends to decrease rapidly due to the drop in the reservoir pressure and closure of ***, it is crucial to monitor opening of fractures for the effective development of carbonate reservoirs. Three methods for monitoring of opening of fractures including tracer indicators method,Warren and Root method and Victorin’s empirical relation, are applied in the Logovskoye oil reservoir, acarbonate Tournaisian-Famennian formation in Upper Kama Region, Perm Krai, Russia. The threemethods provide reliable estimation of the opening of fractures, which match the reported laboratorydata obtained on thin sections of core samples. The limitations of each method are also discussed. Thetracer indicator method is time-consuming, the Warren and Root method includes hydrodynamic studiesand requires shutdown of wells influencing the oil production, and the application of Victorin’s relationrequires estimation of initial opening and current compressibility of fractures, which can be done usinganalysis of cores or tracer indicators studies. The appropriate method for monitoring of opening offractures should be chosen according to available resources, time, and economic targets of the development project.

关键词： Carbonates Well tests Tracer indicators Warren and Root method Indicator injection

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Stress dependence of elastic wave dispersion and attenuation in fluid-saturated porous layered media

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Science China Earth Sciences 2023年第11期66卷 2622-2634页

作者： Fubin CHEN Zhaoyun ZONG Xingyao YIN alexey STOVAS National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China Laoshan Laboratory Qingdao 266580China Centre for Exploration Geophysics Curtin UniversityGPO Box U1987PerthWA 6845Australia Department of Geoscience and Petroleum Norwegian University of Science and Technology(NTNU)Trondheim 7031Norway

The fluid-saturated porous layered(FSPL)media widely exist in the Earth's subsurface and their overall mechanical properties,microscopic pore structure and wave propagation characteristics are highly relevant to the in-situ ***,the effect of in-situ stress on wave propagation in FSPL media cannot be well explained with the existing *** fill this gap,we propose the dynamic equations for FSPL media under the effect of in-situ stress based on the theories of poroacoustoelasticity and anisotropic *** loss mechanism is considered to account for the stress-dependent wave dispersion and attenuation induced by global wave-induced fluid ***'s elastic anisotropy parameters are used to represent the anisotropy of the skeleton.A plane-wave analysis is implemented on dynamic equations yields the analytic solutions for fast and slow P waves and two S *** results show that the elastic anisotropy parameters significantly determine the stress dependence of wave *** tortuosity and permeability have remarkable effects on fast and slow P-wave velocity curves and the corresponding attenuation peaks but have little effect on S-wave *** difference in velocities of two S waves occurs when the FSPL medium is subjected to horizontal uniaxial stress,and the S wave along the stress direction has a larger velocity,which implies that the additional anisotropy other than that induced by the beddings appears due to horizontal ***,the predicted velocity results have the reasonable agreement with laboratory *** equations and results are relevant to a better understanding of wave propagation in deep strata,which provide some new theoretical insights in the rock physics,hydrocarbon exploration and stress detection in deep-strata shale reservoirs.

关键词： Fluid-saturated porous layered(FSPL)media In-situ stress Theory of poroacoustoelasticity Wave equation Wave dispersion and attenuation

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Nanoscopic imaging of oxidized graphene monolayer using tip-enhanced Raman scattering.

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Nano Research 2018年第12期11卷 6346-6359页

作者： Joseph M.Smolsky alexey V.Krasnoslobodtsev Department of Physics University of Nebraska at Omaha6001Dodge StreetOmaha NE 68182USA

Tip-enhanced Raman scattering (TERS) can be used for the structural and chemical characterization of materials with a nanoscale resolution, and offers numerous advantages compared to other forms of imaging. We use TERS to track the local structural features of a CVD-grown graphene monolayer. Ag nanoparticles were added to AFM probes using ion-beam sputtering in order to make them TERS-active. Such modification provides probes with large factors of enhancement and good reproducibility. TERS measurements on graphene show an emergence of a defect-induced D-Raman band and a strain-induced shoulder of the graphene’s G-band. Comparison of TERS results with micro-Raman for oxidized graphene suggests that local oxidation occurs with the introduction of sp3 defects, under TERS conditions.

关键词： graphene Raman spectroscopy tip-enhanced Raman scattering graphene oxidation

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Mapping of Landslides and Other Catastrophic Processes in the Area of the Beichuan City(Sichuan Province,China) after the Earthquake of May 12~th 2008

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地学前缘 2009年第S1期16卷 72-73页

作者： alexey Petrasov Sergeev Institute of Environmental Geoscience Russian Academy of Sciences

The Wenchuan earthquake of 2008 in the Sichuan Province(China)is one of the most destructive earthquakes in recent *** killed about 89 thousand people and caused considerable economic *** the first phase of research the main objective was in detailed image interpretation and mapping of the territory of a key site around Beichuan City,at the initial stage of adaptation of the natural-technical environment after the catastrophic *** this purpose we used

关键词： landslides Beichuan dammed lake geomorphological mapping

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Topology of triple-point metals

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Chinese Physics B 2019年第7期28卷 54-72页

作者： Georg W.Winkler Sobhit Singh alexey A.Soluyanov Microsoft Quantum Microsoft Station Q University of California Santa Barbara California 93106-6105 USA Department of Physics and Astronomy Rutgers University Piscutuwny New Jersey 08854 USA Institute of Physics University of Zurich. Winterthurerstrasse 190 8057 Zurich Switzerland Department of Physics. St. Petersburg State University St. Petersburg 199034Russia

We discuss and illustrate the appearance of topological fermions and bosons in triple-point metals where a band crossing of three electronic bands occurs close to the Fermi *** bosons appear in the phonon spectrum of certain triple-point metals, depending on the mass of atoms that form the binary triple-point *** first provide a classification of possible triple-point electronic topological phases possible in crystalline compounds and discuss the consequences of these topological phases, seen in Fermi arcs, topological Lifshitz transitions, and transport *** we show how the topological phase of phonon modes can be extracted and proven for relevant ***,we show how the interplay of electronic and phononic topologies in triple-point metals puts these metallic materials into the list of the most efficient metallic thermoelectrics known to date.

关键词： topological metals topological phonons electronic structure thermoelectrics

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