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Synthesis of crystalline perovskite-structured SrTiO_3 nanoparticles using an alkali hydrothermal process

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International Journal of Minerals,Metallurgy and Materials 2016年第1期23卷 109-115页

作者： u.K.N.Din T.h.T.Aziz M.M.Salleh A.A.umar Institute of Microengineering and Nanoelectronics (IMEN) Universiti Kebangsaan Malaysia

We report an experimental route for synthesizing perovskite-structured strontium titanate （SrTiO3） nanocubes using an alkali hydrothermal process at low temperatures without further heating. Furthermore, we studied the influence of heating time （at 180℃） on the crystallinity, morphology, and perovskite phase formation of SrTiO3. The SrTiO3 powder, which is formed via nanocube agglomeration, transforms into cubic particles with a particle size of 120--150 nm after 6 h of hydrothermal sintering. The crystallinity and percentage of the perovskite phase in the product increased with heating time. The cubic particles contained 31.24at% anatase TiO2 that originated fi＇om the precursor. By varying the weight ratio of anatase TiO2 used to react with the strontium salt precursor, we reduced the anatase-TiO2 content to 18.8at%. however, the average particle size increased when the anatase-TiO2 content decreased.

关键词： strontium titanate nanoparticles anatase hydrothermal synthesis

Influence of surface liquid segregation on corrosion behavior of semi-solid metal high pressure die cast aluminium alloys

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中国有色金属学会会刊：英文版 2010年第S3期20卷 837-841页

作者： E.P.MASuKu h.MLLER u.A.CuRLE P.C.PISTORIuS Materials Science and Manufacturing Council for Scientific Industrial ResearchPretoriaSouth Africa Department of Materials Science and Engineering Carnegie Mellon UniversityPittsburghUSA

The corrosion behavior(in chloride medium) of the surface layer of SSM-hPDC plates of alloys 7075-T6 and 2024-T6 was compared with that of the wrought alloys 7075-T6 and *** testing was performed in deaerated 3.5%NaCl *** separate tests,the open-circuit potential was monitored in aerated 3.5% NaCl for 30 min after *** electrochemical tests show that there is no significant difference in the pitting potential of the wrought alloys and that of the Cu-enriched surfaces of the SSM-hPDC alloys.

关键词： semi-solid metal(SSM) forming wrought aluminium alloys alloy 7075 alloy 2024 corrosion surface liquid segregation

Asymmetric Magnetization Reversal Probed by Recoil Loop Measurements in an Exchange Biased La0.67Sr0.33MnO3/La0.33Ca0.67MnO3 Bilayer Film

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Chinese Physics Letters 2008年第1期25卷 278-281页

作者：王志宏 h.-u.hABERMEIER G.CRISTIANI 孙继荣沈保根 State Key Laboratory of Magnetism Institute of Physics Chinese Academy of Sciences PO Box 603 Beijing 100080 Max-Planck-Institut fur Festkoperforschung Heisenbergstrasse 1 D-70569 Stuttgart Germany

We exploit the recoil loop measurements to study La0.07 Sr0.33 Mn O3/La0.33 Ca0.67 Mn O3 bilayer film. the asymmetric magnetization reversal in an exchange-biased It is found that the recoil curve encloses a marked area only in the second quadrant of the hysteresis loop, and the recoil susceptibility in the descending branch of the major loop is evidently higher than that in the ascending branch. The study indicates that the exchange anisotropy of a unidirectional nature and an orientation deviated from the easy axis of the ferromagnetic layer plays a crucial role in creating the reversal asymmetry.

关键词： hYSTERESIS LOOPS ANISOTROPY MAGNETS

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同步辐射高分辨率衍射光束线的设计(英文)

光学精密工程 2007年第12期15卷 1900-1907页

作者： u Pietsch O h Seeck Faculty of Physics Siegen UniversityD-57068 SiegenGermany hASYLAB at DESY D-22603 HamburgGermany

介绍了第三代同步辐射高分辨率X射线衍射光束线的总体设计。给出了高分辨率衍射的基本原理并描述了获得确定光子能量的近平行高强度X射线光束线所必需的光学元件。特别是用X射线动力学理论,解释了双晶及四次反射晶体单色器。作为一个实... 详细信息

介绍了第三代同步辐射高分辨率X射线衍射光束线的总体设计。给出了高分辨率衍射的基本原理并描述了获得确定光子能量的近平行高强度X射线光束线所必需的光学元件。特别是用X射线动力学理论,解释了双晶及四次反射晶体单色器。作为一个实例,介绍了将于2009年开始在德国汉堡运行的一个新的同步辐射源PETRAⅢ的高分辨率衍射( highRes)光束线的设置情况。通过优化光学部件,对微米尺寸光束,q空间的分辨减小到Δq=10-5nm-1,光通量大于1011cts/s。

关键词：同步辐射衍射光束线高分辨率

Investigation ofmodified zinc borate glasses doped with BaO as a nuclear radiation-shieldingmaterial

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Radiation Detection Technology and Methods 2018年第2期2卷 101-107页

作者： h.A.Saudi S.u.El-Kameesy Department of Physics Faculty of Science(Girls’Branch)Al-Azhar UniversityCairoEgypt Department of Physics Faculty of ScienceAin Shams UniversityCairoEgypt

Background Radiation protection and detection have been a main interest for *** prepared glass samples were subjected to experimental investigations to evaluate their mechanical and attenuation *** a consequence,the values of the mass attenuation coefficient,total electronic cross section,the effective atomic number and an effective electron number were determined and utilized to assess the shielding effectiveness of the investigated glass *** mass attenuation coefficients of these samples were calculated theoretically using WinXcom *** Preparation of glass of borate with zinc and barium can withstand shock,heat and corrosion to be used as a radiation *** Glass samples were prepared by melt quenching *** and molar volume measurements were obtained by applying the Archimedes *** hardness was measured by using a microhardness tester(Leco AMh 100,uSA)for sample *** thermal behavior of the glass samples was investigated by differential scanning calorimetry(DSC).Also,by using a scintillator detector(1.5″×1.5″NaI(Tl))exposed to ^(232)Th,^(137)Cs and ^(60)Co gamma ray sources with accuracy range 0.12%.Results The investigated glasses have relatively good gamma ray attenuation properties,water resistance ability and thermal stability with increasing barium ***,they can be used in containers for keeping radioactive waste and radioactive *** The changes in the molar volume and density show approximately opposite linear ***,μm is dependent on the chemical compositions of glass samples and energy of gamma *** agreement between the experimentally obtained mass attenuation coefficient values and the corresponding theoretical predictions based on the known WinXcom program was ***,the effect of gamma irradiation on this glass is minor because its impact on the hardness values and dissolution rate is extremely small.

关键词： Borate glasses Shielding properties hardness Durabil

The spin-isospin decomposition of the nuclear symmetry energy from low to high density

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Chinese Physics C 2020年第5期44卷 114-118页

作者： Wenmei Guo M.Colonna V.Greco u.Lombardo h.-JSchulze Department of Physics Anhui Normal UniversityWuhu 241000China Laboratori Nazionali del Sud(INFN) Via S.Sofia 6295123 CataniaItaly Dipartimento di Fisica e Astronomia Via S.Sofia 6495123 CataniaItaly INFN Sezione di CataniaVia S.Sofia 6295123 CataniaItaly

The energy per particle BA in nuclear matter is calculated up to high baryon density in the whole isospin asymmetry range from symmetric matter to pure neutron *** results,obtained in the framework of the Brueckner-hartree-Fock approximation with two-and three-body forces,confirm the well-known parabolic dependence on the asymmetry parameterβ=(N?Z)/A(β^2 law)that is valid in a wide density *** investigate the extent to which this behavior can be traced back to the properties of the underlying interaction,aside from the mean field approximation,the spin-isospin decomposition of BA is *** indications suggest that theβ^2 law could be violated at higher densities as a consequence of the three-body *** raises the problem that the symmetry energy,calculated according to theβ^2 law as a difference between BA in pure neutron matter and symmetric nuclear matter,cannot be applied to neutron *** should return to the proper definition of the nuclear symmetry energy as a response of the nuclear system to small isospin imbalance from the Z=N nuclei and pure neutron matter.

关键词： symmetry energy nuclear interaction spin-isospin decomposition nuclear matter

Wavelet analysis of stagnation point flow of non-Newtonian nanofluid

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Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1211-1226页

作者： M.hAMID M.uSMAN R.u.hAQ4 Z.h.KhAN Wei WANG School of Mathematical Sciences Peking UniversityBeijing 100871China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Department of Electrical Engineering Bahria UniversityIslamabad 44000Pakistan State Key Laboratory of hydraulics and Mountain River Engineering College of Water Resource & HydropowerSichuan UniversityChengdu 610065China Key Laboratory of Advanced Reactor Engineering and Safety Ministry of Education Tsinghua UniversityBeijing 100084China

The wavelet approach is introduced to study the influence of the natural convection stagnation point flow of the Williamson fluid in the presence of thermophysical and Brownian motion effects. The thermal radiation effects are considered along a permeable stretching surface. The nonlinear problem is simulated numerically by using a novel algorithm based upon the Chebyshev wavelets. It is noticed that the velocity of the Williamson fluid increases for assisting flow cases while decreases for opposing flow cases when the unsteadiness and suction parameters increase, and the magnetic effect on the velocity increases for opposing flow cases while decreases for assisting flow cases. When the thermal radiation parameter, the Dufour number, and Williamson’s fluid parameter increase, the temperature increases for both assisting and opposing flow cases. Meanwhile, the temperature decreases when the Prandtl number increases. The concentration decreases when the Soret parameter increases, while increases when the Schmidt number increases. It is perceived that the assisting force decreases more than the opposing force. The findings endorse the credibility of the proposed algorithm, and could be extended to other nonlinear problems with complex nature.

关键词： Williamson nanofluid heat and mass transfer stagnation point flow assisting and opposing flow Chebyshev wavelet method

Effects of an Intense Laser Field and hydrostatic Pressure on the Intersubband Transitions and Binding Energy of Shallow Donor Impurities in a Quantum Well

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Chinese Physics Letters 2011年第7期28卷 254-257页

作者： u.Yesilgul F.ungan E.Kasapoglu h.Sari I.Sökmen Department of Physics Cumhuriyet University58140 SivasTurkey Department of Physics Dokuz Eylül University35160 IzmirTurkey

We have calculated the intersubband transitions and the ground-state binding energies of a hydrogenic donor impurity in a quantum well in the presence of a high-frequency laser field and hydrostatic *** calculations are performed within the effective mass approximation,using a variational *** conclude that the laser field amplitude and the hydrostatic pressure provide an important effect on the electronic and optical properties of the quantum *** to the results obtained from the present work,it is deduced that(i)the binding energies of donor impurity decrease as the laser field increase,(ii)the binding energies of donor impurity increase as the hydrostatic pressure increase,(iii)the intersubband absorption coefficients shift toward lower energies as the hydrostatic pressure increases,(iv)the magnitude of absorption coefficients decrease and also shift toward higher energies as the laser field *** is hopeful that the obtained results will provide important improvements in device applications.

关键词： method hydrostatic donor

Dual solutions in MhD stagnation-point flow of Prandtl fluid impinging on shrinking sheet

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Applied Mathematics and Mechanics(English Edition) 2014年第7期35卷 813-820页

作者： N.S.AKBAR Z.h.KhAN R.u.hAQ S.NADEEM Department of Basic Science & humanities College of Electrical & Mechanical Engineering(CEME) National University of Sciences and Technology Islamabad 46000 Pakistan School of Mathematical Sciences Peking University Department of Mathematics University of Malakand Khyber Pakhtunktwo 18800 Pakistan Department of Mathematics Quaid-i-Azam University Islamabad 44000 Pakistan

The present article investigates the dual nature of the solution of the magneto- hydrodynamic （MhD） stagnation-point flow of a Prandtl fluid model towards a shrinking surface. The self-similar nonlinear ordinary differential equations are solved numerically by the shooting： method. It is found that the dual solutions of the flow exist for cer- tain values of tile velocity ratio parameter. The special case of the first branch solutions （the classical Newtonian fluid model） is compared with the present numerical results of stretching flow. The results are found to be in good agreement. It is also shown that the boundary layer thickness for the second solution is thicker than that for the first solution.

关键词： stagnation-point flow shrinking sheet Prandtl fluid magnetohydrody-namic (MhD) dual solution shooting method