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Effect of Anti-Diffusion Oxide Layer on Enhanced Thermal Stability of Magnetic Tunnel Junctions

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Chinese physics Letters 2006年第4期23卷 932-935页

作者：张宗芝赵慧 Cardoso S. Freitas p.p. Department of Optical Science and Engineering State Key Laboratory for Advanced Photonic Materials and Devices Fudan University Shanghai 200433 INESC-MN R. Alves Redol 9 1000 and Physics Department IST Av. Rovisco Pals 1096 Lisbon Portugal

Magnetic tunnel junctions （MTJs） with one proper oxidized FeOx layer placed between the Al oxide barrier and the top CoFe pinned layer show large tunnelling-magnetoresistance （TMR） signals as high as 39% after anneal at 380℃. The increased TMR signal may originate from the as-deposited Fe/FeOx （non-magnetic） layers changing to Fe＋magnetic FeOy layer （some Fe3O4 and mostly other kind of magnetic Fe oxide） after high temperature anneal. The maximum TMR value （TMR ） and the corresponding temperature Ts where the TMRmax occurs upon annealing are closely associated with the oxidation time of the AlOx and FeOx layers, too long oxidation for the Fe layers is detrimental for the TMR value. In addition to the enhanced AlOx barrier quality upon anneal, the improved thermal stability is also attributed to the Mn diffusion retardation by the presence of the FeOx layer which acts as an antidiffusion layer. For MTJs without the interposed FeOx layer, the TMR signal reduction at 300℃ originates from the Mnlr/CoFe partially decoupling and CoFe/AlOx interface polarization loss due to the significant Mn diffusion.

关键词： ROOM-TEMpERATURE MAGNETORESISTANCE INTERFACE BARRIERS DIFFUSION

Sensor location in concrete slabs with various layout of opening using modified ‘FEMS-COMAC’ approach

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Earthquake Engineering and Engineering Vibration 2020年第1期19卷 205-222页

作者： H.Vosoughifar p.Manafi Department of Civil and Environmental Engineering University of Hawaii at ManoaHonoluluUSA Department of Civil Engineering South Tehran BranchIslamic Azad UniversityTehranIran

Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSp) in slabs with various opening positions is the most important issue in structural health monitoring(SHM) to increase reliability. In this study, a novel approach of OSp was evaluated to obtain the number and placement of sensors using examination of the closed loop performance. The nonlinear finite element(NFE) was used to discretize the mechanism behavior of slab. Multi-Objective Optimization based on the coordinate modal assurance criterion(COMAC) and cost considerations was considered in the optimization processes. All of the analysis, discretization and optimization process was designed and developed as a novel approach in Matlab by the author under the name ‘FEMS-COMAC’(FEM analysis of slab with COMAC). The points in the finite element method(FEM) mesh were classified as line by line information along the slab. The OSp in each line was optimized according to the objective function. The slabs with various width, thickness, aspect ratio and opening position were selected as case studies. The results of the OSp using the COMAC algorithm around the slab openings were compared with the novel ‘FEMS-COMAC’ method. The statistical analysis according Mann-Whitney criteria shows that there were significant differences between them in some of the case studies(mean p-value=0.54).

关键词： two-way concrete slabs openings OSp MAC COMAC

Toluene Alkylation to Selective Formation of p-Xylene over Co-Crystalline ZSM-12/ZSM-5 Catalyst

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Journal of Natural Gas Chemistry 2007年第1期16卷 37-41页

作者： p.N.Joshi p.S.Niphadkar p.A.Desai R.patil V.V.Bokade Catalysis Division National Chemical LaboratoryPune-411008India

The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 （MTW）/ZSM-5 co-crystalline zeolite in 40：60 proportions have been synthesized by the same molar gel composition, but at different temperatures and periods than that of ZSM-12 and ZSM-5, separately. All the prepared samples are characterized by XRD, SEM, BET, and XRF. The activity of toluene alkylation was investigated with a mixture of toluene and methanol as a feed over the ZSM-12, ZSM-12/ZSM-5 co-crystalline, ZSM-5, and physical mixture of ZSM-12/ZSM-5. From characterization, it is observed that the ZSM-12/ZSM-5 co-crystalline material is different from that of ZSM-12, ZSM-5, and their physical mixture. Further, the ZSM-12/ZSM-5 co-crystalline zeolite produces the highest content of xylene and has better selectivity for p-xylene than ZSM-12, ZSM-5, and their physical mixture.

关键词： ZSM-12 ZSM-5 co-crystalline toluene alkylation p-xylene

Androgen receptor functions in prostate cancer development and progression

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Asian Journal of Andrology 2014年第4期16卷 561-564页

作者： Steven p Balk Division of Hematology-Oncology Beth Israel Deaconess Medical Center Harvard Medical School Boston MA USA.

The androgen receptor （AR） is critical for the normal development ofprostate and for its differentiated functions. The consistent expression of AR in prostate cancer （pCa）, and its continued activity in pCa that relapse after androgen deprivation therapy （castration-resistant prostate cancer （CRpC））, indicate that at least a subset of these genes are also critical for pCa development and progression. This review addressed AR regulated genes that may be critical for pCa, and how AR may acquire new functions during pCa development and progression.

关键词： @@

A New Thermodynamic Calculation Method for Binary Alloys: part I: Statistical Calculation of Excess Functions

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Journal of Materials Science & Technology 2002年第3期18卷 237-241页

作者： XingqiuCHEN p.Rogl 等 SchoolofMaterialsandMetallurgy NortheasternUniversityShenyang110004China InstitutfuerphysikalischeChemie UniversitaetWienWahringerstrαβe42A-1090WienAusria

The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for calculating the formation heat of binary alloys. A calculation method of excess thermodynamic functions for binary alloys, the formulas of integral molar excess properties and partial molar excess properties for solid ordered or disordered binary alloys have been developed. The calculated results are in good agreement with the experimental values.

关键词： Binary alloy Thermodynamic Excess functions Enthalpy

Free torsional vibration of cracked nanobeams incorporating surface energy effects

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Applied Mathematics and Mechanics(English Edition) 2017年第2期38卷 217-230页

作者： R. NAZEMNEZHAD p. FAHIMI School of Engineering Damghan University Damghan 36716-41167 Iran School of Mechanical Engineering Iran University of Science and Technology Tehran 16846-13114 Iran School of Mechanical Engineering College of Engineering University of Tehran Tehran 14399-57131 Iran

This paper investigates surface energy effects, including the surface shear modulus, the surface stress, and the surface density, on the free torsional vibration of nanobeams with a circumferential crack and various boundary conditions. To formulate the problem, the surface elasticity theory is used. The cracked nanobeam is modeled by dividing it into two parts connected by a torsional linear spring in which its stiffness is related to the crack severity. Governing equations and corresponding boundary conditions are derived with the aid of Hamilton＇s principle. Then, natural frequencies are obtained analytically, and the influence of the crack severity and position, the surface energy, the boundary conditions, the mode number, and the dimensions of nanobeam on the free torsional vibration of nanobeams is studied in detail. Results of the present study reveal that the surface energy has completely different effects on the free torsionl vibration of cracked nanobeams compared with its effects on the free transverse vibration of cracked nanobeams.

关键词： torsional vibration cracked nanobeam surface energy

A high-capacity viologen-based anolyte for high energy density neutral pH aqueous redox-flow batteries

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Journal of Energy Chemistry 2023年第3期78卷 222-231,I0007页

作者： Anubhav Kumar Bijay p.Tripathi Department of Materials Science and Engineering Indian Institute of Technology DelhiHauz KhasNew Delhi 110016India

Redox-ﬂow batteries(RFBs)are a promising energy storage technology with remarkable scalability and safety for storing vast amounts of renewable energy and mitigating outputﬂuctuations of renewable power *** demonstrate a neutral pH aqueous RFB using a custom-designed 1’,1’’’,1’’’’’-(benzene-1,3,5-triyltris(methylene))tris(1-(3-(trimethyl ammonio)propyl)-[4’’,4’’’-bipyridine]-1,1’-diium)nonachloride(BTTMpB)as a 3 e-storage *** custom design with the high polarization in charge density has led to the excellent water solubility of 4.0 M in H_(2)O(321.6 A h L^(-1))and 2.4 M in 2.0 M NaCl(192.9 A h L^(-1)).The density functional theory(DFT)calculations and electrochemical experiments have shown 3 e-storage response of BTTMpB with a diffusion coefﬁcient of 3.1×10^(-6)cm^(2) s^(-1)and rate con-stant of 1.6×10^(-2)cm s^(-1) for theﬁrst reduction *** synthesized anolyte was paired with(Ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte enabling a 0.92 V aqueous RFB with 125.9 W h L^(-1)theoretical energy *** aqueous RFB has an excellent cycling performance from 10-30 m A cm^(-2),energy efﬁciency up to 80%,capacity retention of 99.96%per cycle at 20 m A cm^(-2),and a high demonstrated energy density of 29.1 W h L^(-1).

关键词： Energy storage Aqueous redox-ﬂow battery Redox-active organic material Viologen derivative Solvation energy

Entropy generation analysis from the time-dependent quadratic combined convective flow with multiple diffusions and nonlinear thermal radiation

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Chinese Journal of Chemical Engineering 2023年第1期53卷 46-55页

作者： p.M.patil Bharath Goudar Department of Mathematics Karnatak UniversityPavate NagarDharwad 580003India Wrangler Dr.D.C.pavate Institute of Mathematical Sciences Karnatak UniversityDharwad 580003India

Diffusions of multiple components have numerous applications such as underground water flow, pollutant movement, stratospheric warming, and food processing. particularly, liquid hydrogen is used in the cooling process of the aeroplane. Further, liquid nitrogen can find applications in cooling equipment or electronic devices, i.e., high temperature superconducting(HTS) cables. So, herein, we have analysed the entropy generation(EG), nonlinear thermal radiation and unsteady(time-dependent) nature of the flow on quadratic combined convective flow over a permeable slender cylinder with diffusions of liquid hydrogen and nitrogen. The governing equations for flow and heat transfer characteristics are expressed in terms of nonlinear coupled partial differential equations. The solutions of these equations are attempted numerically by employing the quasilinearization technique with the implicit finite difference approximation. It is found that EG is minimum for double diffusion(liquid hydrogen and heat diffusion)than triple diffusion(diffusion of liquid hydrogen, nitrogen and heat). The enhancing values of the radiation parameter R_(d) and temperature ratio θ_(w) augment the fluid temperature for steady and unsteady cases as well as the local Nusselt number. Because, the fluid absorbs the heat energy released due to radiation, and in turn releases the heat energy from the cylinder to the surrounding surface.

关键词： Unsteady flow Entropy Radiation Quasilinearization technique Numerical analysis Quadratic combined convection

Nonlinear mixing-based terahertz emission in inclined rippled density plasmas

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Chinese physics B 2023年第6期32卷 384-390页

作者： K Gopal A p Singh S Divya Rajdhani College Department of Physics&ElectronicsUniversity of DelhiNew DelhiIndia Computational plasma Dynamics Laboratory Rajdhani CollegeDepartment of Physics&ElectronicsUniversity of DelhiNew DelhiIndia

We propose to investigate the THz field generation using nonlinear mixing mechanism of laser beat wave with inclined rippled density *** laser pulses with frequencies(ω_(1),ω_(2)) and wave vectors(k_(1),k_(2)) co-propagate and resultant laser beat wave forms at beat frequency(ω_(1)-ω_(2)).Laser beat wave imparts a nonlinear force on the ambient electrons and pushes them outward with nonlinear velocity v_(NL).Coupling of induced density perturbation and nonlinear velocity v_(NL)generates nonlinear currents at laser beat frequency that further generates electromagnetic field E_((ω_(1)-ω_(2))) in terahertz(THz)*** the present scheme,density ripples are introduced at an angle with respect to laser propagation and flat Gaussian index(f) is introduced in laser field profile that transform curved top of Gaussian field envelope into flat top field *** combined effect of flat laser pulses with inclined density ripples in plasmas shows 10-fold enhancement in THz field amplitude when flat-Gaussian index(f) varies from 1 to ***,the THz field intensifies when density ripples inclination increases upto a certain angle and then decreases.

关键词： terahertz inclined ripple flat laser laser plasma interaction