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Nonlinear analysis on dynamic buckling of eccentrically stiffened functionally graded material toroidal shell segment surrounded by elastic foundations in thermal environment and under time-dependent torsional loads

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Applied mathematics and mechanics(English Edition) 2016年第7期37卷 835-860页

作者： D.v.DUNG P.m.vUONG Department of mathematics Mechanics and InformaticsVietnam National University Faculty of Civil and Industrial National University of Civil Engineering

The nonlinear analysis with an analytical approach on dynamic torsional buckling of stiffened functionally graded thin toroidal shell segments is investigated. The shell is reinforced by inside stiffeners and surrounded by elastic foundations in a thermal environment and under a time-dependent torsional load. The governing equations are derived based on the Donnell shell theory with the yon Karman geometrical nonlinearity, the Stein and mcElman assumption, the smeared stiffeners technique, and the Galerkin method. A deflection function with three terms is chosen. The thermal parameters of the uniform temperature rise and nonlinear temperature conduction law are found in an explicit form. A closed-form expression for determining the static critical torsional load is obtained. A critical dynamic torsional load is found by the fourth-order Runge-Kutta method and the Budiansky-Roth criterion. The effects of stiffeners, foundations, material, and dimensional parameters on dynamic responses of shells are considered.

关键词： toroidal shell segment functionally graded material (FGm) stiffened shell,critical static and dynamic torsional load thermal environment

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

Experience gained in analyzing severe accidents for WWER RP using CC SOCRAT

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Frontiers in Energy 2021年第4期15卷 872-886页

作者： S.I.PANTYUSHIN А.v.LITYSHEv A.v.NIKOLAEvA O.v.AULOvA D.L.GASPAROv v.v.ASTAKHOv m.A.BYKOv Non-stationary Thermohydraulics Department OKB Gidropress JSC 142103PodolskRussia

The current Russian regulatory documents on the safety of nuclear power plant(NPP)specify the requirements regarding design basis accidents(DBAs)and beyond design basis accidents(BDBAs),including severe accidents(SAs)with core meltdown,in NPP design(NP-001-15,NP-082-07,and others).For a rigorous calculational justification of BDBAs and SAs,it is necessary to develop an integral CC that will be in line with the requirements of regulatory documents on verification and certification(RD-03-33-2008,RD-03-34-2000)and will allow for determining the amount of data required to provide information within the scope stipulated by the requirements for the structure of the safety analysis report(SAR)(NP-006-16).The system of codes for realistic analysis of severe accidents(SOCRAT)(formerly,thermohydraulics(RATEG)/coupled physical and chemical processes(SvECHA)/behavior of core materials relocated into the reactor lower plenum(HEFEST))was developed in Russia to analyze a wide range of SAs at NPP with water-cooled water-moderated power-generating reactor(WWER)at all stages of the *** to the code and broadening of its applicability are continually being pursued by the code developers(Nuclear Safety Institute of the Russian Academy of Sciences(IBRAE RAN))with OKB Gidropress JSC and other ***,the SOCRAT/В1 code can be used as a base tool to obtain realistic estimates for all parameters important for computational justification of the reactor plant(RP)safety at the in-vessel stage of SAs with fuel *** perform analyses using CC SOCRAT/В1,the experience gained during execution of thermohydraulic codes is applied,which allows for minimizing the uncertainties in the results at the early stage of an accident *** study presents the results of the work performed in 2010–2020 in OKB Gidropress JSC using the CC SOCRAT/В*** have been considered to develop calculational models and analyze SAs using CC *** process,which is cle

关键词： system of codes for realistic analysis of severe accidents(SOCRAT) design basis accidents(DBAs) severe accidents(SAs) computer code(CC) nuclear power plant(NPP)design water-cooled water-moderated(WWER) modeling model safety requirements

Influence of FCA Welding Process Parameters on Distortion of 409m Stainless Steel for Rail Coach Building

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Journal of Iron and Steel Research International 2013年第1期20卷 71-78页

作者： m v venkatesan N murugan B m Prasad A manickavasagam Department of mechanical Engineering Coimbatore Institute of TechnologyCoimbatore 641014TNIndia Integral Coach Factory Indian RailwaysChennai 600038TNIndia

The influence of flux cored arc welding （FCAW） process parameters such as welding current, travel speed, voltage and CO2 shielding gas flow rate on bowing distortion of 409m ferritic stainless steel sheets of 2 mm in thickness was discussed. The bowing distortions of the welded plates were measured using a simple device called profile tracer. An experimental regression equation was developed to predict the bowing distortion and with this equation, it is easy to select optimized process parameters to achieve minimum bowing distortion. It is revealed that the FCAW process parameters have significant influence on bead profile and the bowing distortion.

关键词： bowing distortion ferritic stainless steel flux cored arc welding statistical model rail coach distortion measurement

Joint effect of quasicrystalline icosahedral and L1_(2)-strucutred phases precipitation on the grain structure and mechanical properties of aluminum-based alloys

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Journal of materials Science & Technology 2021年第28期87卷 196-206页

作者： A.G.mochugovskiy N.Yu.Tabachkova m.Esmaeili Ghayoumabadi v.v.Cheverikin A.v.mikhaylovskaya National University of Sciences and Technology“mISIS” 119049Leninskiy Ave.4MoscowRussia Prokhorov General Physics Institute of the Russian Academy of Sciences MoscowRussia

Dispersoid hardening is a key factor in increasing the recrystallization resistance and mechanical strength of non-heat treatable aluminum-based *** and Zr are the main elements that form dispersoids in commercial Al-based *** this work,the annealing-induced precipitation behavior,the grain structure,and the mechanical properties of Al-3.0 mg-1.1 mn and Al-3.0 mg-1.1 mn-0.25 Zr alloys were *** microstructure and the mechanical properties were significantly affected by annealing regimes after casting for both *** research demonstrated a possibility to form high-density distributed quasicrystalline-structured I-phase precipitates with a mean size of 29 nm during low-temperature annealing of as-cast *** manganese-bearing precipitates of I-phase increased recrystallization resistance and significantly enhanced the mechanical strength of the alloys *** estimated strengthening effect owing to I-phase precipitation was 150 *** to the formation of L1_(2)-structured Al3Zr dispersoids with a mean size of 5.7 nm,additional alloying with Zr increased yield strength by about 90 *** L1_(2)-phase strengthening effect was estimated through the dislocation bypass looping and shearing mechanisms.

关键词： Aluminum alloy Quasicrystals Dispersoid hardening Recrystallization mechanical properties

Chemoselective Dehydrogenation of 3-[2-(3,4-Dihydro-1-naphthalenyl)ethyl]imidazolidine-2,4-diones: a New and Convenient Synthesis of 13,16-Diazaequilenin analogs

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Chinese Journal of Chemistry 2004年第10期22卷 1196-1199页

作者： PARIHAR J.A RAmANA m.m.v Department of Chemistry University of Mumbai Santacruz (E) Mumbai-400098 IndiaDepartment of Chemistry University of Mumbai Santacruz (E) Mumbai-400098 India

The synthesis of the title compounds starting with the chemoselective dehydrogenation of 3-[2-(3,4-dihydro-1-naphthalenyl)ethyl]imidazolidine-2,4-diones has been described.

关键词： chemoselective dehydrogenation imide reduction intramolecular cyclization 13,16-diazasteroid

Erosion corrosion control of 6061 aluminum alloy in multi-phase jet impingement conditions with eco-friendly green inhibitor

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Chinese Journal of Chemical Engineering 2020年第2期28卷 340-347页

作者： m.Lavanya v.Ramachandra murthy Padmalatha Rao Department of Biotechnology Manipal Institute of TechnologyManipal Academy of Higher EducationManipalKarnatakaIndia Department of Chemistry Manipal Institute of TechnologyManipal Academy of Higher EducationManipalKarnatakaIndia

Erosion corrosion performance of 6061 aluminum alloy in simulated sea water slurry was investigated under multi-phase jet impingement conditions. The main objective of the work is to study erosion–corrosion of a material with engineering application and mitigate it using eco-friendly green inhibitor. Experiments were performed with the sand concentration of 0.3% and 0.3 μm size. The effect of temperature and flow rate on the performance of inhibitor was explored. Electrochemical methods were adopted for erosion-corrosion measurements. Experiments revealed that starch could mitigate erosion-corrosion with a maximum reduction efficiency of 58% at temperature of 303 K and flow rate of 4 L·min–1. Inhibition efficiency decreased with increase in flowrate and temperature. EIS spectrum demonstrated that the corrosion process in the presence on inhibitor was both charge transfer and mass transfer controlled. A key role of hydrodynamics in the performance of corrosion inhibitor was confirmed by the present study.

关键词： Erosion-corrosion Green-inhibitor Electrochemical studies Aluminum alloy Simulated sea water

A photometric study of two neglected eclipsing binaries

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Research in Astronomy and Astrophysics 2021年第7期21卷 192-198页

作者： v.Kudak m.Fedurco v.Perig S.Parimucha Laboratory of Space Researches Uzhhorod National UniversityUzhhorodDaleka Str.2A88000Ukraine Institute of Physics Faculty of ScienceUniversity of P.J.SafarikKosicePark Angelinum 904001Slovakia

We present the first BvR photometry,period variation and photometric light curve analysis of two poorly studied eclipsing binaries,v1321 Cyg and CR *** were carried out from November 2017 to January 2020 at the observatory of Uzhhorod National *** variations were studied using all available early published as well as our minima *** used the newly developed ELIS a code for the light curve analysis and determination of photometric parameters for both *** found that v1321 Cyg is a close detached eclipsing system with a low photometric mass ratio of q=0.28 which suggests that the binary is a post-mass transfer *** significant period changes in this system are *** Tau is,on the other hand,a semi-detached system where the secondary component almost fills its Roche *** detected a long-term period increase at a rate of 1.49 × 10^(-7) d yr^(-1),which supports mass transfer from the lower mass secondary component to the more massive primary.

关键词： binaries:close binaries:eclipsing stars:individual(v1321 Cyg CR Tau)

Photoelectrochemical activity of ZnO:Ag/rGO photo-anodes synthesized by two-steps sol-gel method

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Chinese Physics B 2022年第5期31卷 691-702页

作者： D Ben Jemia m Karyaoui m A Wederni A Bardaoui m v martinez-Huerta m Amlouk R Chtourou Laboratory of Nanomaterials and Renewable Energy Systems LANSER Research and Technology Center of EnergyBorj-Cedria Science and Technology ParkBP 952050 Hammam-LifTunisia Faculty of Science of Tunis University of Tunis El ManarTunisia Laboratory of Physics of materials and Nanomaterials Applied to the Environment(LaPhymNE) Faculty of Sciences of GabesCite ErriadhUniversity of Gabes6079 GabesTunisia lnstitute of Catalysis and Petrochemistry CSICin MadridSpain Laboratory of Nanomaterials Nanotechnology and Energy(L2NE)University of Tunis El ManarTunisia

This work investigated the influence of silver plasmon and reduced graphene oxide(r GO)on the photoelectrochemical performance(PEC)of Zn O thin films synthesized by the sol-gel *** physicochemical properties of the obtained photo-anodes were systematically studied by using several characterization *** x-ray diffraction analysis showed that all samples presented hexagonal wurtzite structure with a polycrystalline *** and energy dispersive x-ray(EDX)studies confirmed the existence of both Ag and r GO in Zn O:Ag/r GO thin *** estimated grain size obtained from scanning electron microscopy(SEm)analysis decreased with Ag doping,then increased to a maximum value after r GO *** Uv-vis transmission spectra of the as-prepared Zn O:Ag and Zn O:Ag/r GO thin films have shown a reduction in the visible range with a redshift at the absorption *** bandgaps were estimated to be around 3.17 e v,2.7 e v,and 2.52 e v for Zn O,Zn O:Ag,and Zn O:Ag/r GO,***,the electrical measurements revealed that the charge exchange processes were enhanced at the Zn O:Ag/r GO/electrolyte interface,accompanied by an increase in the(PEC)performance compared to Zn O and Zn O:Ag ***,the photocurrent density of Zn O:Ag/r GO(0.2 m A·cm^(-2)) was around 4 and 2.22 times higher than photo-anodes based on undoped Zn O(0.05 m A·cm^(-2)) and Zn O:Ag(0.09 m A·cm^(-2)),***,from the flat band potential and donor density,deduced from the mott-Schottky,it was clear that all the samples were n-type semiconductors with the highest carrier density for the Zn O:Ag/r GO photo-anode.

关键词： zinc oxide reduced graphene oxide silver doping sol-gel photoelectrochemical performance