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Structural, Dielectric, and magnetic Properties of Ba-Doped multiferroic Bismuth Ferrite

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Acta metallurgica Sinica(English Letters) 2015年第8期28卷 958-964页

作者： Rubayyat mahbub Takian Fakhrul.md Fakhrul Islam mehedi Hasan Arman Hussain m.A.matin m.A.Hakim Department of Glass and Ceramic Engineering Bangladesh University of Engineering and Technology Department of materials and metallurgical Engineering Bangladesh University of Engineering and Technology

The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi1-xBaxFeO3 samples. Bi1-xBaxFeO3 samples（x = 0.1, 0.2 and 0.3） were synthesized by the conventional solid-state reaction method using nano-powders of Bi2O3, Fe2O3, and BaCO3. Thereafter, field emission scanning electron microscope and X-ray diffraction（XRD） techniques were used to examine the structure and phase of the samples. Phase analysis by XRD indicated that the single-phase perovskite structure was formed with possible increment in lattice parameter with increasing Ba doping. Complex permeability（u＇iand u＇＇i） measured using impedance analyzer confirmed the increase in magnetic property with increasing Ba doping. Finally, dielectric constant（k） was analyzed as a function of temperature at different frequencies. Dielectric constant as high as 2900 was attained in this research for Bi0.8Ba0.2FeO3 sample due to reduction in leakage current at this composition.

关键词： multiferroic Bismuth ferrite Dielectric Complex permeability

Influence of the wakes of rotating spokes on the performance of a turbine exhaust diffuser

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Journal of Thermal Science 2010年第3期19卷 206-210页

作者： m.Kuschel J.R.Seume Institute of Turbomachinery and Fluid Dynamics Leibniz University HannoverD-30167 HannoverGermany

The design of turbine exhaust diffusers is still commonly based upon conservative design charts which do not consider the influence of the components installed upstream such as the last turbine *** on investigations with different spoke wheels which approximate the blade wakes of the last turbine stage,the influence of a rotating bladed disc on the flow in a exhaust diffuser is *** pressure recovery for an annual diffuser with 15° half cone angle and the 5 mm spoke wheel used in the model test is very high and nearly independent on the rotational speed and the corresponding Strouhal *** a 20° annual diffuser,the pressure recovery increases with Strouhal number

关键词： turbine exhaust diffuser rotating wakes separation

New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

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Plasma Science and Technology 2007年第6期9卷 690-694页

作者： Ph.ROBIN-JOUAN m.YOUSFI AREVA T & D High Voltage Switchgear Research Centre 130 rue L.BLUM 69611 VilleurbanneFrance University of Toulouse LAPLACE-UMR 5213 CNRSUPS118 Route de Narbonne31062 Toulouse Cedex 9France

The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure, namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively. Based on solving a multi-term electron Boltz- mann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions. The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K. These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

关键词： breakdown electric field hot dissociated SF6 high voltage gas-circuit-breaker

Simultaneous photoinduced generation of Fe^(2+) and H_2O_2 in rivers:An indicator for photo-Fenton reaction

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Journal of Environmental Sciences 2016年第9期28卷 34-38页

作者： Khan m.G.mostofa Hiroshi Sakugawa Institute of Surface-Earth System Science Tianjin University Graduate School of Biosphere Science Department of Environmental Dynamics and ManagementHiroshima University

The photo-Fenton reaction is a key source of the highly reactive hydroxyl radical（HOU） that is produced by the reaction of simultaneous photo-induced generation of Fe^（2＋）-dissolved organic matter（DOm） with H_2O_2 in sunlit surface waters as well as in the treatment of organic pollutants in the advanced oxidation processes（AOPs）.Concentrations of both H_2O_2 and Fe^（2＋）-DOm were dependent on time and total solar intensity flux,and their levels were highest in the diurnal samples collected at noon compared with the samples collected during the period before sunrise and after sunset.H_2O_2 and Fe^（2＋）-DOm concentrations during monthly readings were also found higher in comparison with the diurnal samples,shortly before sunrise or after sunset.A π-electron bonding system is formed between Fe and the functional groups in DOm（Fe-DOm）,through electron donation from the functional groups of DOm to an empty d-orbital of *** π-electron is loosely bound and is highly susceptible to a rapid excitation upon light exposure that will provide better understanding of the formation of aqueous electrons,superoxide radical anions,H_2O_2 and finally,photo-Fenton reactions,*** results imply that simultaneous generation of H_2O_2 and Fe^（2＋）-DOm upon sunlight exposure during the daytime is most likely to be the key photo-Fenton reaction pathway,taking place in surface waters.

关键词： Photo-Fenton reaction Fe^(3+) Fe^(2+) Dissolved organic matter H_2O_2 Light

A Search on Dirac Equation

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Chinese Physics Letters 2007年第11期24卷 3024-3027页

作者： m. Kocak, B. Gonül Department of Engineering Physics Faculty of Engineering University of Gaziantep 27310 Gaziantep Turkey

The solutions, in terms of orthogonal polynomials, of Dirac equation with analytically solvable potentials are investigated within a novel formalism by transforming the relativistic equation into a Schrodinger-like one. Earlier results are discussed in a unified framework, and some solutions of a large class of potentials are given.

关键词： coated conductor buffer layer self-epitaxy CeO2

Numerical Study of Greenhouse Nocturnal Heat Losses

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Journal of Thermal Science 2011年第4期20卷 377-384页

作者： F.Berroug E.K.Lakhal m.El Omari m.Faraji H.El Qarnia Laboratoire d'Automatique de l'Environnement et Procédés de Transfert UniversitéCadi AyyadFacultédes Sciences Semlalia-Département de PhysiqueMarrakech-MarocAffiliéau CNRSTURAC 28 Laboratoire de Physique des materiaux MicroelectroniqueAutomatique et TechniqueDepartement de PhysiquesFaculte des Sciences Ain ChockUniversite Hassan IICasablanca-Maroc

In this study we quantify and analyze different components of nocturnal losses from a heated greenhouse with the presence of vegetation for typical winter weather conditions in marrakesh-morocco,using a non linear model,based on the greenhouse heat and mass *** was found that 12% of the total input heat was dissipate as a sensible and latent leakage losses,66% was lost by convective exchange through air-inner *** gain of energy at the inner-cover is dissipated at the outer-cover by radiation(66%)and convection(34%).This results point toward some practical measures to reduce heat losses:increasing air tightness,using covering materials with low-emissivity in the long wave band or putting up an external thermal curtain should provide significant energy savings.

关键词： Greenhouse energy balance heat losses numerical analysis.

Effect of coolant inhibitors on AZ91D

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Rare metals 2004年第3期23卷 255-259页

作者： I.m.Baghni WUYinshun ZHANGWei LIJiuqing mechanicalEngineeringDepatartment EngineeringCollegeofTajouraLibya CorrosionandProtectionCenter UniversityofScienceandTechnologyBeijingBeijing100083China

The inhibition effects of sodium vanadate along with inorganic coolantinhibitors were examined on corrosion of AZ91D in ASTm D1384-80 corrosive water by polarizationmeasurements. The galvanic corrosion of AZ91D coupled to 3003, 6063, and 356 Al alloys were alsotested. An effective combination of inhibitors containing (but not limited to) sodium vanadate,silicate, and nitrate was proposed for inhibition of AZ91D and prevention of galvanic corrosion.

关键词： failure and protection of materials inhibitors potentiodynamicpolarization coolant AZ91D magnesium alloy

Generalized Second Law of Thermodynamics in Wormhole Geometry with Logarithmic Correction

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Chinese Physics Letters 2011年第7期28卷 55-58页

作者： Faiz-ur-Rahman Salahuddin m.Akbar Centre for Advanced mathematics and Physics National University of Sciences and Technology(NUST)IslamabadPakistan

We construct various cases for validity of the generalized second law(GSL)of thermodynamics by assuming the logarithmic correction to the horizon entropy of an evolving *** is shown that the GSL is always respected fo... 详细信息

关键词： correction thermodynamics horizon

IDENTIFICATION OF STIFFNESS COEFFICIENTS OF LAmINATED COmPOSITE PLATES

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中国有色金属学会会刊：英文版 1997年第3期7卷 46-50页

作者： Wang, XC Shen, XP Yuichiro, m Xu, BY N CHINA UNIV TECHNOL BEIJING 100041PEOPLES R CHINA TSING HUA UNIV DEPT MECH ENGNBEIJING 100084PEOPLES R CHINA IBARAKI UNIV DEPT ENGNHITACHIIBARAKI 316JAPAN

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ＩＤＥＮＴＩＦＩＣＡＴＩＯＮＯＦＳＴＩＦＦＮＥＳＳＣＯＥＦＦＩＣＩＥＮＴＳＯＦＬＡＭＩＮＡＴＥＤＣＯＭＰＯＳＩＴＥＰＬＡＴＥＳ①ＷａｎｇＸｉａｏｃｈｕｎ，ＳｈｅｎＸｉｎｐｕ，ＭａｓｕｄａＹｕｉｃｈｉｒｏ，ＸｕＢｉｎｇｙｅＮｏｒｔｈＣｈｉｎａＵｎｉｖｅ...

关键词： inverse analysis composite laminated plate stiffness coefficient