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Analysis of the discrete contact characteristics based on the Greenwood-Williamson model and the localization principle

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Friction 2024年第5期12卷 1042-1056页

作者： Anastasiya A.YAKOVENKO irina G.GORYACHEVA Ishlinsky Institute for Problems in Mechanics RAS Moscow119526Russia

The contact of a rigid body with nominally flat rough surface and an elastic half-space is *** solve the contact problem,the Greenwood-Williamson statistical model and the localization principle are *** developed contact model allows us to investigate the surface approach and the real contact area with taking into account the asperities *** is shown that the mutual influence of asperities changes not only contact characteristics at the macroscale,but also the contact pressure distribution at the *** follows from the results,the inclusion in the contact model of the effect of the mutual influence of asperities is especially significant for studying the real contact area,as well as the contact characteristics at high applied *** results calculated according to the proposed approach are in a good agreement with the experimentally observed effects,i.e.,the real contact area saturation and the additional compliance exhaustion.

关键词： surface roughness elasticity Greenwood-Williamson model localization principle asperity interaction

Early Jurassic Climate Warming in Eastern Siberia: First Macrofloristic Evidence from Irkutsk Basin, Russia

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 1035-1050页

作者： Andrey FROLOV irina MASHCHUK Institute of the Earth's Crust Siberian Branch of the Russian Academy of SciencesIrkutsk664033Russia

Numerous new records of Ferganiella, Podozamites, and Schidolepium, including a new species, Ferganiella ivantsovii sp. nov., are described from the Early Jurassic(Toarcian) Middle Subformation of the Prisayan Formation from the Euro-Sinian paleofloristic region in the Irkutsk Basin, Eastern Siberia, Russia. An analysis of the paleogeographic distribution of Ferganiella and Podozamites shows that both genera were the most diverse and numerous in the East Asian province of the Euro-Sinian region and in the Northern Chinese province of the Siberian region during the Early and Middle Jurassic. These phytochoria were located in the subtropical and temperate subtropical climate zones, which allows us to consider Ferganiella and Podozamites as thermophilic plants, which are important indicators of the Early Toarcian climatic optimum. Their abundance in the Irkutsk Basin thus may indicate Early Toarcian warming;further abundant Schidolepium cones, which produced Araucariacites pollen, typical for Euro-Sinian flora complement the scenario. Thus, the new finds are the first macrofloristic indicators of the Toarcian climatic optimum in the Irkutsk Basin.

关键词： paleobotany Ferganiella Podozamites Schidolepium Toarcian climatic optimum paleobiogeography Siberian paleofloristic region Irkutsk

The Disintegration of a Floating Ferrofluid Layer into an Ordered Drop System in a Vertical Magnetic Field

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2205-2218页

作者： Christina Khokhryakova Konstantin Kostarev irina Mizeva Laboratory of Dispersed System Dynamics Institute of Continuous Media Mechanics UrB RASPerm614018Russia Laboratory of Hydrodynamical Stability Institute of Continuous Media Mechanics UrB RASPerm614018Russia Laboratory of Turbulence Institute of Continuous Media Mechanics UrB RASPerm614018Russia

Magnetic fluids,also known as ferrofluids,are versatile functional materials with a wide range of *** applications span from industrial uses such as vacuum seals,actuators,and acoustic devices to medical uses,including serving as contrast agents for magnetic resonance imaging(MRI),delivering medications to specific locations within the body,and magnetic hyperthermia for cancer *** use of a non-wettable immiscible liquid substrate to support a layer of magnetic fluid opens up new possibilities for studying various fluid flows and related instabilities in multi-phase systems with both a free surface and an *** presence of two deformable boundaries within a ferrofluid layer significantly reduces the critical magnetic field strength required to transform the layer into an organized system of drops or polygonal figures evolving according to the intensity,frequency and direction of the considered magnetic *** paper experimentally investigates this problem by assuming a uniform magnetic field perpendicular to the *** specific subject has not been previously explored *** critical magnetic field intensity required to destabilize the ferrofluid layer is determined based on the layer’s thickness and the fluid’s initial magnetic *** is demonstrated that the critical magnetic field strength needed to disrupt the initially continuous ferrofluid layer increases with the layer’s ***,an increase in the ferrofluid’s magnetic susceptibility results in a decrease in the critical magnetic field *** emerging droplet structures are analyzed in terms of the number of drops,their size,and the periodicity of their *** number of droplets formed depends on the initial thickness of the layer,the presence or absence of a stable rupture in the upper layer,and the rate at which the magnetic field strength is increased to the critical value.A characteristic viscous time is proposed

关键词： Ferrofluid liquid substrate normal field instability ordered droplet structure

Effect of sodium nitroprusside on the microrheological properties of red blood cells in di®erent media

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Journal of Innovative Optical Health Sciences 2024年第5期17卷 23-31页

作者： Petr Ermolinskiy Matvey Maksimov Andrei Lugovtsov Alexey Muravyov irina Tikhomirova Alexander Priezzhev Faculty of Physics M.V.Lomonosov Moscow State University Moscow 119991Russia Faculty of Physical Education K.D.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia Faculty of Natural Sciences K.D.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia

Red blood cell(RBC)aggregation as well as their deformation signi¯cantly affects blood *** processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the *** purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in *** properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,*** study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged *** washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased ***-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.

关键词： Sodium nitroprusside nitric oxide red blood cells RBC aggregation diffuse light scattering laser diffractometer

When Fleeing Matters:Differences in Escape Behaviours of Three Northeast Asian Anurans

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Asian Herpetological Research 2024年第1期15卷 41-48页

作者： Yoonjung YI Zoljargal PUREVDORJ irina MASLOVA Yikweon JANG Amaël BORZÉE Laboratory of Animal Behaviour and Conservation College of Life SciencesNanjing Forestry UniversityNanjing 210037JiangsuChina Division of EcoScience and Department of Life Sciences Ewha Womans UniversitySeoul 03760Republic of Korea Department of Biology School of MathematicsMongolian State University of EducationUlaanbaatar 210648Mongolia Department of Forest and Environmental Resources Chungnam National UniversityDaejeon 34134Republic of Korea Federal Scientific Center of the East Asia Terrestrial Biodiversity Far Eastern Branch of Russian Academy of SciencesVladivostok 690022Russia

Prey species may have their own optimal escape strategy to balance predation risks and the energetic cost of *** species have an advantage when maintaining a short fleeing distance,while others may favour an earlier escape based on microhabitat,size,or body ***,we examined the escape behaviour of the three syntopic Northeast Asian anuran species:Mongolian toads(Strauchbufo raddei),Amur brown frogs(Rana amurensis),and Japanese treefrogs(Dryophytes japonicus)in Mongolia,Russia,China and DPR *** examined flight initiation distance(FID;the distance from a potential predator to the point when the individual starts to flee)and distance fled(DF;distance between flight initiation and flight termination points)of each species and the effects of microhabitat,sex,and body *** raddei and *** had a longer FID than ***,and *** also had a longer DF than *** trends remained similar when dividing FID and DF by a size proxy(snout-vent length)for all *** suggests that the treefrog *** used a strategy to stay immobile even when they were detected,and the toad *** reacted quicker and more sensitively to predators despite the presence of *** *** had a significantly longer FID than males suggesting that females are more sensitive to predation risk in this species,but body size was not significant for any of the three *** results indicate that the three sympatric species have different escaping strategies,likely related to differences in physiology and crypticity.

关键词： amphibian distance fled escape behaviour flight initiation distance predation

Changes in renal function and morphological variations of kidney diseases in rheumatoid arthritis patients

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Asian Journal of Urology 2024年第2期11卷 304-310页

作者： Yan Tang Yuliya Varavko Raisa Aringazina irina Menshikova College of Medical Technology Yongzhou Vocational Technical CollegeYongzhouChina Department of Internal Diseases Propaedeutics Irkutsk State Medical UniversityIrkutskRussian Federation Department of Internal Diseases No.1 Non-Commercial Joint-Stock Society“West Kazakhstan Marat Ospanov Medical University”AktobeKazakhstan Department of Hospital Therapy No.1 I.M.Sechenov First Moscow State Medical University of Ministry of Health of Russian Federation(Sechenov University)MoscowRussian Federation

Objective:Rheumatoid nephropathy is one of the most severe extra-articular manifestations of rheumatoid arthritis(RA)associated with a very unfavorable *** study aimed to identify changes in renal function and morphological variations of kidney diseases in RA ***:The study enrolled patients(126 patients)between 18 and 55 years of age with a confirmed active RA of more than 12 *** patient underwent the following range of laboratory and instrumental research methods:general clinical analysis of blood and urine,performing urinalysis according to Nechiporenko method;determining daily proteinuria;determining the blood content of glucose,urea,creatinine,uric acid,total bilirubin,liver transaminase level,ionogram,lipidogram,and coagulogram;determining the blood content of rheumatoid factor,anti-streptolysin O,and C-reactive protein;and X-ray of the joints of hands and *** function was examined by estimating glomerular filtration rate,tubular reabsorption index,and renal functional *** studying the morphological changes in the kidneys under ultrasound examination,renal biopsy was performed in 31 patients with RA with urinary syndrome(proteinuria more than 0.3 g per day and hematuria).Results:Nephropathy in RA is characterized by impaired renal function and manifested by an increased blood creatinine and a decrease in glomerular filtration rate and renal functional *** morphological variations of nephropathy at RA,mesangial proliferative glomerulonephritis prevails,accounting for 48.4%of *** disorders include the secondary amyloidosis(29.0%of patients),tubulointerstitial nephritis(16.1%),membranous glomerulonephritis(3.2%),and focal-segmental glomerulosclerosis(3.2%).Conclusion:Kidney damage is a common systemic manifestation of RA with a long and active course,a major nephropathy trigger.

关键词： Rheumatoid nephropathy Secondaryrenal amyloidosis Mesangial proliferative glomerulonephritis Renal functional reserve

Formation of Water Quality of Surface Water Bodies Used in the Material Processing

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Fluid Dynamics & Materials Processing 2024年第4期20卷 815-828页

作者： Tatyana Lyubimova Anatoly Lepikhin Yanina Parshakova irina Zayakina Alibek Issakhov Laboratory of Computational Fluid Dynamics Laboratory Institute of Continuous Media Mechanics UB RASPerm614068Russia Laboratory of Land Hydrology Problems Mining Institute UB RASPerm614000Russia Department of Theoretical Physics Perm State UniversityPerm614990Russia Department of Mathematical and Computer Modeling Al-Farabi Kazakh National UniversityAlmaty050040Republic of Kazakhstan

In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required *** in many regions of the world,there is an acute problem of providing industry with water of a required *** solution is an urgent and difficult *** water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors,and is often significantly heterogeneous not only in the water area,but also in *** a rule,the water supply of large industrial enterprises is located along the river *** are the most important nodes of river *** the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water *** recent years,thanks to the data of satellite images,the interest of researchers in the phenomenon of mixing the waters of merging rivers has *** nature of the merger is influenced by the formation of transverse *** the framework of this work,a study of vorticity,as well as the width of the mixing zone,depending on the distance from the confluence,the speeds of the merging rivers and the angle of confluence was carried *** the consumer properties of water are largely determined by its chemical and physical indicators,the intensity of mixing,determined largely by the nature of the secondary circulation,is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing *** characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties,but also for organizing an effective monitoring system for confluence zones.

关键词： Water for material processing water quality formation of transverse circulation

Selection of shaped charges parameters for producing aluminum particles with velocities in the range of 2.5-16 km/s

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Defence Technology（防务技术） 2024年第8期38卷 126-135页

作者： Vladimir I.Kolpakov Sergey V.Fedorov Ekaterina P.Vinogradova irina A.Bolotina Bauman Moscow State Technical University Moscow 105005Russia

Testing rocket and space technology objects in ground conditions for resistance to the impact of meteoroids and fragments of space debris can be carried out using shaped charges. To substantiate the design parameters of shaped charges that ensure the formation of aluminum particles in a wide velocity range(from 2.5 to 16 km/s), numerical modeling of the formation process was carried out within the framework of a two-dimensional axisymmetric problem of continuum mechanics using three different computing codes to increase the reliability of the results. The calculations consider shaped charges with a diameter of 20-100 mm with aluminum liners of various shapes. It is shown that the formation of particles with velocities close to the lower limit of the considered range is ensured by gently sloping segmental liners of degressive thickness. To form higher-velocity particles with velocities over 5 km/s, it is proposed to use combined liners, the jet-forming part of which has the shape of a hemisphere of constant thickness or the shape of a semi-ellipsoid or semi-superellipsoid of rotation of degressive thickness.

关键词： Space debris Meteoric impact Explosion Shaped charge High-velocity aluminum element Segmental liner Combined liner Numerical simulation

Detection and evaluation of different morphological forms of Mycoplasma hominis in human semen

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Asian Journal of Andrology 2024年第1期26卷 71-76页

作者： Elizaveta Bragina Tatyana Sorokina Avtandil Chogovadze Yulia Shevchenko Vyacheslav Chernykh Olga Barkhatova irina Rakovskaya Research Centre for Medical Genetics Moscow 115522Russia A.N.Belozersky Institute of Physico-Chemical Biology Lomonosov Moscow State University Moscow 119992Russia Reprolab Limited Liability Company Moscow 119333Russia N.I.Pirogov Russian National Research Medical University Moscow 117997Russia Federal Government Budgetary Institution"National Research Center for Epidemiology and Microbiology Named after Honorary Academician N.F.Gamaleya of the Ministry of Health of the Russian Federation" Moscow 123098Russia

Recently discovered microcolonial forms of Mycoplasma hominis(***)and their impact on human spermatogenesis are *** spermatozoa of 125 fertile men(sperm donors;from Reprobank[Reproductive Tissue Bank,Moscow,Russial)and of 93 patients with fertility problems(from the Federal State Budgetary Institution"Research Centre for Medical Genetics[RCMG]",Moscow,Russia)were *** colonies of *** and microcolonies were detected by molecular biological methods,culture of bacteria,and transmission electron *** unique structure of microcolonial cells,in which the cytoplasmic cylinder is surrounded by concentric electron-dense and electron-light layers with a periodicity of 12-14 nm,and the ability of microcolonial cells to attach to spermatozoa are *** patients with lower sperm quality,microcolonies of *** were detected 2.5 times more frequently than classical *** detection of microcolonies in the ejaculate and the frequent isolation of microcolonies from sperm samples of patients with fertility problems suggest that microcolonial cells may be one cause of infertility.

关键词： ejaculate fertility Mycoplasma hominis spermatogenesis transmission electron microscopy