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Chinese Physics B 2018年第2期27卷 607-612页

作者： sh Khandanjou M Ghoranneviss sh Saviz M Reza Afshar Plasma Physics Research Center Science and Research Branch Islamic Azad University Department of Materials Engineering Science and Research Branch Islamic Azad University

In the present investigation, Ni_（50）Ti_（25）Al_（25）（at.%） mechanically alloyed powder is deposited on carbon steel *** the coating process, the substrate is heated to temperature ranging from room temperature to 400℃. The microstructure, porosity, microhardness, adhesion strength, and corrosion behavior of the coating are investigated at different substrate temperatures. Results show that coating porosity is lower on high temperature surface. Microhardness and adhesion strength of the deposition layer on the substrate without preheating have lower values than with preheating. The polarization test result shows that corrosion performance of the coating is dependent on micro cracks and porosities and the increasing of substrate temperature can improve the quality of coating and corrosion performance.

关键词： Ni50Ti25Al25 coating air plasma spray planetary ball milling inter-metallic compounds corrosion resistance

Solving two-dimensional Volterra-Fredholm integral equations of the second kind by using Bernstein polynomials

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Applied Mathematics(A Journal of Chinese Universities) 2017年第1期32卷 68-78页

作者： M.sh.dahaghin sh.Eskandari Department of Mathematics Shahrekord University Shahrekord Iran

In this paper, we present a numerical method for solving two-dimensional VolterraFredholm integral equations of the second kind（2DV-FK2）. Our method is based on approximating unknown function with Bernstein polynomials. We obtain an error bound for this method and employ the method on some numerical tests to show the efficiency of the method.

关键词： Volterra approximating approximate variational proof iterative uniformly exact wavelet inequality

Ethnocultural heritage of the North-Eastern Caucasus as a factor of eco-tourism development

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Journal of Mountain Science 2024年第8期21卷 2810-2824页

作者： Zaburaeva Khava sh. Complex Research Institute named after Kh.I.Ibragimov of the Russian Academy of Sciences Grozny 366002Russia

The North-East Caucasus is a multi-ethnic mountain macroregion with a rich cultural heritage,insufficiently studied in the context of the ecotourism *** fill this gap and identify promising directions of environmentally safe forms of tourism,the author used in-depth review of modern literature to investigate the features of ecological tourism and the problems of preserving ethno-cultural heritage,and used historical and comparative-geographical methods to analyze the development of the tangible and intangible cultural heritage of the indigenous peoples of the North-Eastern Caucasus in different historical periods and to identify the geographical peculiarities of the distribution of historical and cultural monuments(tower buildings),pilgrimage sites and centers of traditional crafts and *** part of the planned expeditions,the author personally visited some historical monuments and handicraft centers for a deeper study of ethno-cultural *** cartographic method made it possible to visualize the *** results of the research show that the ethnocultural heritage of the North-East Caucasus is formed by material(historical and cultural monuments)and immaterial elements of culture(language,customs,traditions,ethnic identification)of those peoples,who live *** ethnocultural heritage is considered as the most important factor in the development of the tourism *** is revealed that this region has a large potential for development in various areas of *** highest concentration of religious buildings focused in mountainous *** tower structures were erected in mountainous and high-altitude *** ancient times to the present day there have been preserved various types of crafts and trades(pottery,metalworking,burka making,jewelry making,carpet weaving,gold embroidery,wood and stone carving,etc.),which can become objects of *** ethnocultural heritage of the North-East Caucasus needs to be preserved a

关键词： Mountainous districts Sustainable development Prospects Stone Towers Folk crafts

Two-dimensional analysis of a negative differential conductance gate transistor as a THz emitter

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Plasma Science and Technology 2017年第4期19卷 15-22页

作者： sh RAHMATALLAHPUR A ROSTAMI S KHORRAM Photonics and Nanocrystal Research Lab.(PNRL) Faculty of Electrical and Computer EngineeringUniversity of TabrizTabriz 51666-14761Iran Photonics Group Research Institute for Applied Physics and Astronomy(RIAPA)University of TabrizTabriz 51664-14761Iran

We investigate plasma modes in a transistor including a negative differential conductance in the gate. The analytical results show that the plasma wave generation is substantially influenced by the lateral direction （width of the transistor）, gate leakage current and ＇viscosity. The injection from the gate （opposed to the gate leakage current） can improve the plasma oscillations and their amplitude with respect to ordinary transistors. We also estimate, which to our best knowledge has been derived for the first time, the total power emitted by the transistor and the emitted pattern which qualitatively gives reasonable agreement with the experimental data. The results show that the radiated power depends on various parameters such as drift velocity, momentum relaxation time, gate leakage current and especially the lateral direction. A negative gate current enhances the power while the gate leakage current decreases the power.

关键词： terahertz emitter solid state plasma two-dimensional analysis negative differentialconductance

IMPORTANCE OF MOIST AMBIENT AND ITS HELICAL ENHANCEMENT EFFECT TO STORM INTENSITY

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Journal of Hydrodynamics 2004年第6期16卷 743-755页

作者： Al-FALAHI Fadha sh. Key Laboratory of Mesoscale Severe Weather Ministry of Education Department of Atmospheric Sciences Nanjing University Nanjing 210093 China

A crucial issue in evolution of severe storm, such as typhoon and even singlesupercell, is to diagnose and predict the sudden intensifying in storm. This paper describes anattempt to investigate the influence and effect of ambient moisture in the development of storm. Itwas mainly through a dynamic way to detect the helical enhancement by ambient moisture. It was foundthat the correlation between the ambient moistness and the intensity of rotating convective cellscan be well analyzed by helicity dynamics. The correlation between environmental streamwisevorticity (i. e. helicity) and vertical velocity (storm updraft or downdraft) is a powerfulindicator to catch favorable or unfavorable conditions for storm evolution. For this purpose, athree-dimensional non-hydrostatic storm-scale model, Advanced Regional Prediction System CARPS) wasemployed in order to numerically simulate a well-documented case of Del City supercell storm indifferent kinds of environmental moistness. Moreover, such different kinds of ambient moistenvironment and the resultant different morphologies and evolutions in the storm clearlydemonstrated that the abundant moistness in the environment that the storm embedded significantlystrengthens tbe storm intensity. In fact, the storm is embedded in much moist environment andtherefore larger instability propagates faster than the one in the drier air. It further producesstronger low-level mesocyclone with a much longer lifetime. The stronger convection and twist in theupdraft indicates that helical enhancement effect by moisture lead to stronger tornadic activity insevere storm.

关键词： moist ambient intensity of storm helical enhancement

A More Accurate Reconstruction Method for Detecting Large-Depth Defects in Plates Using sh Guided Waves

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Acta Mechanica Solida Sinica 2021年第2期34卷 174-183页

作者： Yihui da Qi Li Bin Wang Dianzi Liu Zhenghua Qian State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China School of Engineering University of East AngliaNorwich NR47TJUK

The inspection of thickness thinning defects and corrosion defects is greatly significant for the health prediction of plate *** main aim of this research is to propose a novel and effective approach to achieve the accurate and rapid detection of arbitrary defects using shear horizontal(sh)guided waves,particularly for large-depth and complex *** proposed approach combines the quantitative detection of Fourier transform with a reference model-based strategy to improve the accuracy of large-depth defect *** the shallow defect profile is theoretically constructed by inverse Fourier transform of the product of reflection coefficients and integral coefficients of reference models,the unknown large-depth defect can be initially assessed using the relevant information from a predefined reference *** iteratively updating the integral coefficients of reference models,the accuracy of reconstruction of large-depth defects is much *** achieve the converged defect profile,a termination criterion,the root mean square error,is applied to guarantee the construction of defects with a high level of ***,the hybrid finite element method is used to simulate the propagation of sh guided waves in plates for calculating the reflection coefficients of plates with ***,to demonstrate the capability of the developed reconstruction method for defect detection in terms of accuracy and efficiency,three types of large-depth defect profiles,i.e.,a rectangular flaw,a double-rectangular flaw and a complex flaw,are *** show that the discrepancy between the predicted defect profile and the real one is quite small,even in the largest-depth defect case where the defect depth is equal to 0.733 times the plate thickness,the minimal difference is *** is noted that the fast convergence of the proposed approach can be achieved by no more than ten updates for the worst case.

关键词： Large-depth defect sh guided wave Iterative strategy Reference model Hybrid FEM

Effect of porosity on active damping of geometrically nonlinear vibrations of a functionally graded magneto-electro-elastic plate

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Defence Technology（防务技术） 2022年第6期18卷 891-906页

作者： L.sh Esayas Subhaschandra Kattimani Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India

This paper investigates the effect of porosity on active damping of geometrically nonlinear vibrations(GNLV)of the magneto-electro-elastic(MEE)functionally graded(FG)plates incorporated with active treatment constricted layer damping(ATCLD)*** perpendicularly/slanted reinforced 1-3 piezoelectric composite(1-3 PZC)constricting *** constricted viscoelastic layer of the ATCLD is modeled in the time-domain using Golla-Hughes-Mc Tavish(GHM)*** types of porosity distribution in the porous magneto-electro-elastic functionally graded PMEE-FG plate graded in the thickness *** the coupling effects among elasticity,electrical,and magnetic fields,a three-dimensional finite element(FE)model for the smart PMEE-FG plate is obtained by incorporating the theory of layer-wise shear *** geometric nonlinearity adopts the von K arm an *** study presents the effects of a variant of a power-law index,porosity index,the material gradation,three types of porosity distribution,boundary conditions,and the piezoelectric fiber’s orientation angle on the control of GNLV of the PMEE-FG *** results reveal that the FG substrate layers’porosity significantly impacts the nonlinear behavior and damping performance of the PMEE-FG plates.

关键词： Nonlinear vibration Magneto-electro-elastic(MEE)plates Active treatment constricted layer damping(ATCLD) Porosity distribution Porous functionally graded

Plasmon-enhanced solar water splitting with metal oxide nanostructures： A brief overview of recent trends

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Frontiers of Materials Science 2018年第3期12卷 207-213页

作者： Timur sh. ATABAEV Department of Chemistry School of Science and Technology Nazarbayev University Astana 010000 Kazakhstan

In the last decade, the surface plasmon resonance-enhanced solar water splitting （SWS） has been actively investigated for improved hydrogen production. In this mini-review, we briefly introduce the mechanisms for plasmon-enhanced SWS and then review some representative studies related to these mechanisms. In addition, we also briefly discuss how metal oxide geometry affects the SWS activity in combined metalsemiconductor nanostructures. Finally, we summarize the recent discoveries and proposed a future vision for plasmon-enhanced SWS with metal oxide nanostructures.

关键词： surface plasmon resonance solar water splitting nanostructures noble metals metal oxides

Kerosene-alumina nanofluid flow and heat transfer for cooling application

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Journal of Central South University 2016年第4期23卷 983-990页

作者： M.Mahmoodi sh.Kandelousi Department of Aerospace Engineering Malek-Ashtar University of Technology Department of Mechanical Engineering Babol University of Technology

Kerosene-alumina nanofluid flow and heat transfer in the presence of magnetic field are studied. The basic partial differential equations are reduced to ordinary differential equations which are solved semi analytically using differential transformation method. Velocity and temperature profiles as well as the skin friction coefficient and the Nusselt number are determined analytically. The influence of pertinent parameters such as magnetic parameter, nanofluid volume fraction, viscosity parameter and Eckert number on the flow and heat transfer characteristics is discussed. Results indicate that skin friction coefficient decreases with increase of magnetic parameter, nanofluid volume fraction and viscosity parameter. Nusselt number increases with increase of magnetic parameter and nanofluid volume fraction while it decreases with increase of Eckert number and viscosity parameter.

关键词： magnetic field nanofluid heat transfer differential transformation method

Analysis of maximum pressure in VVER1000/V446 reactor containment for LOCA and MSLB

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Nuclear Science and Techniques 2017年第9期28卷 109-118页

作者： sh. sheykhi S. Talebi Department of Energy Engineering and Physics Amirkabir University of Technology (Tehran Polytechnic) 424 HafezAvenue Tehran 15875-4413 Iran

The highest thermal-hydraulic pressure in the containment occurs when reactor coolant in the first loop and steam in the secondary loop discharge simultaneously,and when the maximum amount of energy from reactor unit enters to containment volume. In this paper, we investigate temperature and pressure variations in the VVER 1000 containment compartments owing to concurrent break in the pipelines of the primary and secondary loops. A two-phase, multicellular model is applied in the presence of non-condensable gases. Convection and conduction through the main heat structures inside the containment are also considered. The predicted results agree well with available data. Maximum values of pressure and temperature in the containment are then calculated and compared to the design values. If LOCA and MSLB occur simultaneously, the maximum pressure would exceed the design value and integrity of the containment would be threatened.

关键词：压力分析失水事故反应堆控制容积最大能量压力变化模型应用内部控制