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Applied Mathematics and Mechanics(English Edition) 2021年第6期42卷 819-840页

作者： v.v.THAM H.Q.TRANT T.M.TU National Univensity of Ciwil Engineering Giai Phong Road 55Hai Ba Trung DistrictHanoi 100000 Vietnam

This paper presents an analytical solution for the free vibration behavior of functionally graded carbon nanotube-reinforced composite(FG-CNTRC) doubly curved shallow shells with integrated piezoelectric layers. Here, the linear distribution of electric potential across the thickness of the piezoelectric layer and five different types of carbon nanotube(CNT) distributions through the thickness direction are considered. Based on the four-variable shear deformation refined shell theory, governing equations are obtained by applying Hamilton's principle. Navier's solution for the shell panels with the simply supported boundary condition at all four edges is derived. Several numerical examples validate the accuracy of the presented solution. New parametric studies regarding the effects of different material properties, shell geometric parameters, and electrical boundary conditions on the free vibration responses of the hybrid panels are investigated and discussed in detail.

关键词： free vibration four-variable shear deformation refined theory functionally graded carbon nanotube-reinforced composite(FG-CNTRC) piezoelectric material

Second-Harmonic Response in Magnetic Nodal-Line Semimetal Fe_(3)GeTe_(2)

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Chinese Physics Letters 2022年第9期39卷 62-66页

作者： v.D.Esin A.A.Avakyants A.v.Timonina N.N.Kolesnikov E.v.Deviatov Institute of Solid State Physics of the Russian Academy of Sciences ChernogolovkaMoscow District2 Academician Ossipyan Str.142432Russia

We experimentally investigate second-harmonic transverse voltage response to ac electrical current for a magnetic nodal-line semimetal Fe_(3)GeTe_(2)(FGT).For zero magnetic field,the observed second-harmonic voltage behaves as a square of the longitudinal current,as it should be expected for nonlinear Hall *** magnetic field behavior is found to be sophisticated:while the first-harmonic response shows the known anomalous Hall hysteresis in FGT,the second-harmonic Hall voltage is characterized by the pronounced high-field hysteresis and flat(B-independent)region with curves touching at low *** high-field hysteresis strongly depends on the magnetic field sweep rate,so it reflects some slow relaxation *** the lowest rates,it is also accomplished by multiple crossing *** shape of the second-harmonic hysteresis is known for skyrmion spin textures in nonlinear *** skyrmions have been demonstrated for FGT by direct visualization techniques,we can connect the observed high-field relaxation with deformation of the skyrmion ***,the second-harmonic Hall voltage response can be regarded as a tool to detect spin textures in transport experiments.

关键词： harmonic relaxation hysteresis

Biochemical Factors Affecting the Quality of Products and the Technology of Processing Deep-Sea Fish, the Giant Grenadier Albatrossia pectoralis

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Journal of Ocean University of China 2020年第3期19卷 681-690页

作者： PIvNENKO T.N. KARPENKO Yu.v. KRASHCHENKO v.v. POZDNYAKOvA Yu.M. ESIPENKO R.v. Far Eastern State Technical Fisheries University Vladivostok 690087Russia

The composition of muscle tissues of a deep-sea species, the giant grenadier(Albatrossia pectoralis), and a mesopelagic species, the Alaska pollock(Theragra chalcogramma), are compared. Grenadier is proved to have a higher moisture content(91.7%) and lower protein(7.4%) and lipid(0.3%) contents. The factors responsible for the softening and moisture separation during processing of grenadier are identified. Contents of some fractions of non-protein nitrogenous components, including trimethylamine oxide(TMAO) and free amino acids, are clarified. The proportion of the main myofibrillar proteins myosin and actin, which is considered as an indicator of efficiency of structure formation in fish muscle tissue during processing, is almost 20% lower in giant grenadier than in pollock. The effects of endogenous protease, Са^2+-ATPase and transglutaminase on the processes of autolysis, denaturation, and possibility of myofibrillar proteins cross-linking were also studied. The proposed technology of getting a nutritionally balanced, gel-like, ready-to-use foodstuff from grenadier fillet includes its enrichment with pollock muscle tissue and supplementing with a binary structure-forming agent containing collagen and chitosan. Nutritional value of the products is assessed by the method of biological assay and by determining the denaturation changes of myofibrillar proteins. The modes of fine mincing and thermal processing, as well as the shelf-life of the finished product are justified. The developed technology of producing a ready-to-eat food from giant grenadier will allow a more efficient use of this underutilized resource.

关键词： giant grenadier Alaska pollock myosin actin proteases ATPase transglutaminase softening structure formation ready-to-eat foodstuffs

A novel multi-scale μCT characterization method to quantify biogenic carbonate production

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Geoscience Frontiers 2024年第6期15卷 43-56页

作者： v.Chandra R.Sicat F.Benzoni v.vahrenkamp v.Bracchi Physical Sciences and Engineering King Abdullah University of Science and TechnologyThuwalSaudi Arabia visualization Core Lab King Abdullah University of Science and TechnologyThuwalSaudi Arabia Biological and Environmental Science and Engineering King Abdullah University of Science and TechnologyThuwalSaudi Arabia Department of Earth and Environmental Sciences University of Milano-BicoccaMilanItaly Saudi Aramco DhahranSaudi Arabia

Biogenic carbonate structures such as rhodoliths and foraminiferal-algal nodules are a significant part of marine carbonate production and are being increasingly used as paleoenvironmental indicators for predictive modeling of the global carbon cycle and ocean acidification ***,traditional methods to characterize and quantify the carbonate production of biogenic nodules are typically limited to two-dimensional analysis using optical and electron *** micro-computed tomography(lCT)is an excellent tool for 3D analysis of inner structures of geomaterials,the trade-off between sample size and image resolution is often a limiting *** this study,we address these challenges by using a novel multi-scale lCT image analysis methodology combined with electron microscopy,to visualize and quantify the carbonate volumes in a biogenic calcareous *** applied our methodology to a foraminiferal-algal nodule collected from the Red Sea along the coast of NEOM,Saudi *** lCT and SEM image analyses revealed the main biogenic carbonate components of this nodule to be encrusting foraminifera(EF)and crustose coralline algae(CCA).We developed a multi-scale lCT analysis approach for this study,involving a hybrid thresholding and machine-learning based image *** utilized a high resolution lCT scan from the sample as a ground-truth to improve the segmentation of the lower resolution full volume lCT scan which provided reliable volumetric quantification of the EF and CCA ***,the EF and CCA layers contribute to approximately 65.5%of the studied FAN volume,corresponding to 69.01 cm3 and 73.32 cm3 respectively,and the rest is comprised of sediment infill,voids and other minor ***,volumetric quantification results in conjunction with CT density values,indicate that the CCA layers are associated with the highest amount of carbonate production within this foraminiferal-algal *** methodology developed for t

关键词： Crustose coralline algae Foraminifera μCT Image analysis Machine learning Marine carbonate factory

Modeling corrosion behavior of gas tungsten arc welded titanium alloy

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中国有色金属学会会刊：英文版 2007年第4期17卷 676-680页

作者： M. Balasubramanian v. Jay abalan v. Balasubramanian Department of Mechanical Engineering Maamallan Institute of Technology Anna University Department of Manufacturing Engineering Anna University Department of Manufacturing Engineering Annamalai University

The pitting corrosion characteristics of pulse TIG welded Ti-6Al-4v titanium alloy in marine environment were explained. Besides the rapid advance of titanium metallurgy, this is also due to the successful solution of problems associated with the development of titanium alloy welding. The preferred welding process of titanium alloy is frequently gas tungsten arc(GTA) welding due to its comparatively easier applicability and better economy. In the case of single pass GTA welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. The benefit of the process is utilized to obtain better quality titanium weldments. Four factors, five levels, central composite, rotatable design matrix are used to optimize the required number of experiments. The mathematical models have been developed by response surface method(RSM). The results reveal that the titanium alloy can form a protective scale in marine environment and is resistant to pitting corrosion. Experimental results are provided to illustrate the proposed approach.

关键词：钛合金脉冲电流钨电极惰性气体保护焊腐蚀行为

Peat Accumulation and Early Carboniferous Environments of the Kizel Coal Basin,the Urals,Russia

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Acta Geologica Sinica(English Edition) 2022年第3期96卷 1098-1112页

作者： Serge v.NAUGOLNYKH Geological Institute of Russian Academy of Sciences Pyzhevsky per.7119017 MoscowRussia

The lithological and geochemical composition and conditions of formation of the coal-bearing deposits of the Kizel Coal Basin in the Perm region of the Urals(central Russia)are described using the two most representative sections,Gubakha-Stary Most and Krestovaya Mountain,based on a detailed“layer-by-layer”*** characteristics of the Lower Carboniferous paleosols from fossil paleosol(FPS-)profiles of the studied region are *** attention is paid to the parent vegetation of the coal-forming processes,based on an analysis of both plant macrofossils and *** peat accumulation in conditions of permanent incoming of clastic material from the Paleo-Urals to the Kizel Basin was probably effective only in more or less stable environments,when the accumulated organic matter produced by plant mortmass was not dissolved by clastic ***,the conditions of coal-forming are reconstructed as a forest swamp,where the main dominants are represented by lycopodiopsids of the order Lepidodendrales,predominantly Lepidodendron *** plants in particular were the source of the initial organic matter for the peat(and later coal)of the Kizel Coal Basin.

关键词： paleobotany palynology coal lithology paleogeography viséan Urals

The role of GRP81 lactate receptor in synaptic transmission regulation: does it enhance endocytosis?

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Neural Regeneration Research 2022年第12期17卷 2657-2658页

作者： Sergei v.Fedorovich Tatsiana v.Waseem Department of Biochemistry Belarusian State UniversityMinskBelarus Independent researcher MinskBelarus

The brain is an expensive tissue in terms of energy *** composes about 2%of body mass and consumes about 20%of all oxygen and calories(Fedorovich and Waseem,2018).For neurons,glucose is the primary energy substrate,although they are able to use ketone bodies,pyruvate and lactate(Fedorovich and Waseem,2018).All these compounds can be metabolized directly in the Krebs cycle,bypassing ***,they are often termed non-glycolytic energy *** of all potential non-glycolytic substrates,lactate is the most physiological(Magistretti and Allaman,2018).Ketone bodies could reach concentrations in blood plasma and cerebrospinal fluid which are sufficient to meet metabolic demands of neurons only under specific non-physiological conditions,e.g.,ketogenic diet and starvation,or during *** contrast,the normal plasma level of lactate is about 1.5 mM and can reach 20 mM during intensive physical exercise.

关键词： ketone glycol cycle

A Model of Irregular Impurity at the Surface of Nanoparticle and Catalytic Activity

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Communications in Theoretical Physics 2012年第7期58卷 55-58页

作者： I.v.Blinova v.v.Gusarov I.Yu.Popov St.Petersburg National Research University of Information Technologies Mechanics and OpticsKronverkskiy49St.Petersburg 197101Russia St.Petersburg State Technological Institute (Technical University) Moskovskiy26St.Petersburg 190013Russia

A problem of nanocatalyst improvement is considered. The existence of irregularities at the surface of nanoparticle leads to the increasing of the surface/volume ratio and, correspondingly, to the improvement of the catalytic activity. But this impurity gives one an additional effect due to the change of the electronic density at the surface. We suggest simple model for the description of this effect. The model allows one to find the discrete spectrum of the Schrdinger operator for nanoparticle. Due to this impurity induced bound states the electron density increases near the surface. It leads to the increase of the catalytic activity of nanoparticles with surface impurities.

关键词： semi-infinite crystal operator spectrum impurity catalytic activity nanoparticle

Dynamics of acousto-rheological properties of polymerized materials on their solidification

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Rare Metals 2007年第S1期26卷 1-4页

作者： RIMLYAND v I BAKHANTSOv A v STARIKOvA v N Physics Department Automation of Physical and Technical Measurements LaboratoryPacific National University

An automated system was designed to study in a continuous regime the rheological properties of the care polymeric compositions using the damped vibration *** a parallel mode measurements of rheological and acoustic characteristics of the care compositions were made on the basis of epoxy *** of shear modulus,viscosity,the sound speed,and the damping coefficient as functions of polymerization were *** of spectral characteristics of acoustic signals in the polymerization were *** of the experimental results obtained reveals that the dynamics of the variation of acoustic and rheological properties is significantly *** major change of acoustic characteristics occurs in the initial stage of the solid state formation when a transition from a liquid-to-gel like state takes *** characteristics vary dramatically at the crossover from a high-viscosity to solid *** the frequency dependencies of an acoustic signal a number of essential features were observed.

关键词： viscosity acoustic properties shear modulus polymerization composition

Kuedinskie Kluchiki, a Unique Middle Permian Biota Locality as a Key-point for Reconstruction of Late Paleozoic Terrestrial Ecosystems of the Urals, Russia

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 850-866页

作者： Serge v.NAUGOLNYKH Geological Institute of Russian Academy of Sciences Pyzhevsky per.7119017 MoscowRussia

Field work focused on the Kuedinskie Kluchiki locality, Perm region, Urals, Russia, which contains a rich assemblage of diverse fossil organisms including higher plants(equisetophytes, pteridosperms, ginkgophytes, conifers, vojnovskyans) represented by stems, leaves and reproductive organs;invertebrates(mollusks, arthropods), and tetrapods(temnospondyl amphibians, seymouriamorphs, cotylosaurs, synapsids, diapsids), as well as bony fishes. General characteristics of the taxonomical composition of the Kuedinskie Kluchiki locality are given. A new peltaspermalean pteridosperm taxon, Compsopteris longipinnata sp. nov., and a voltzialean conifer Archaeovoltzia kuedensis sp. nov. are described. General considerations on the paleoecologic and paleogeographic conditions of the Kuedinskie Kluchiki locality origin are given.

关键词： paleobotany paleoecology taxonomy Lagerst?tten new taxa peltasperms conifers Wordian Cis-Urals