检索结果-内蒙古大学图书馆

Incorporation of lead containing TV tube glass waste in aluminous porcelain

学校读者我要写书评

暂无评论

Incorporation of lead containing TV tube glass waste in alum...

作者： Santos, Talita Faria Paes, Herval Ramos Holanda, José Nilson França Post-Graduate Program in Materials Science and Engineering - PPGECM Universidade Estadual do Norte Fluminense - UENF Campos dos Goytacazes RJ28013-602 Brazil Laboratory of Advanced Materials - LAMAV Universidade Estadual do Norte Fluminense - UENF Campos dos Goytacazes RJ28013-602 Brazil

The aim of this work was to study the incorporation of lead containing TV tube glass waste as a method to provide alternative raw material for aluminous electrical porcelain. For this purpose, aluminous porcelain formulations containing up to 30 wt.% of TV tube glass waste as a replacement for traditional flux material (sodium feldspar) were pressed and fired in air at 1300 ºC using a fast-firing cycle (11 Ω.cm have high potential to work as electrical insulator material. This use of lead containing TV tube glass waste can contribute greatly to reducing the environmental impacts related to it, and also save the sources of non-renewable raw materials used in the electrical porcelain sector. © 2017 Universidade Federal de Sao Carlos. All rights reserved.

关键词： Glass

High pressure effects on non-fluorinated BiS2-based superconductors La1−xMxOBiS2 (M = Ti and Th)

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Fang, Y. Yazici, D. Jeon, I. Maple, M.B. Materials Science and Engineering Program University of California San Diego San DiegoCA92093 United States Center for Advanced Nanoscience University of California San Diego San DiegoCA92093 United States Department of Physics University of California San Diego San DiegoCA92093 United States

Layered LnOBiS2 compounds with Ln = La, Ce, Pr, Nd, and Yb can be rendered conducting and superconducting via two routes, substitution of F for O or the tetravalent ions Ti, Zr, Hf, and Th for trivalent Ln ions. Electrical resistivity measurements on non-fluorinated La0.80Ti0.20OBiS2 and La0.85Th0.15OBiS2 superconductors were performed between ∼1.5 K and 300 K and under pressure up to 2.4 GPa. For both compounds, the superconducting transition temperature Tc, which is ∼2.9 K at ambient pressure, gradually increases with pressure to 3.2-3.7 K at ∼1 GPa, above which it is suppressed and the superconducting transitions become very broad. Measurements of the normal state electrical resistivity of the two compounds reveal discontinuous changes of the resistivity as a function of pressure at ∼0.6 GPa, above which metallic-like electrical conduction is suppressed with increasing pressure. Surprisingly, above 1.3 GPa, semiconducting-like behavior reappears in La0.80Ti0.20OBiS2. This study reveals a new high-pressure phase of La1−xMxOBiS2 containing the tetravalent ions M = Ti, Th which does not favor superconductivity. In contrast, application of pressure to fluorinated LaO0.5F0.5BiS2 produces an abrupt tetragonal-monoclinic transition to a metallic phase with an enhanced Tc. These results demonstrate that the response of the normal and superconducting properties of LaOBiS2-based compounds depends strongly on the atomic site where the electron donor ions are substituted. Copyright © 2018, The Authors. All rights reserved.

关键词： Lanthanum compounds

Overcharge Self-Regulated Li-ion Battery Based on LiFePO4 via a Solid State Combined Cathode

学校读者我要写书评

暂无评论

Overcharge Self-Regulated Li-ion Battery Based on LiFePO4 vi...

MRS Advances

Safety is one of the most crucial problems faced by the lithium-ion battery (LIBs) industry. In this work, we propose a strategy to avoid overcharging of a battery via the application of a solid-state combined cathode. The goal of this research is to produce LIBs with overcharge self-regulation capabilities. In order to achieve self-regulation functionality, 1,4-di-tert-butyl-2,5-dimethoxybenzene (DBB) is added to as-synthesized LiFePO4, post synthesis. DBB has a trigger voltage of 3.9 V. When this voltage is reached, DBB forms a reduced ion that is released into the electrolyte from the cathode side. The DBB ion transfers to the anode side where it oxidizes and transfers back to the cathode side. This process forms a redox shuttle and consumes the extra charges keeping the voltage at a safe level (i.e. 3.9 V). The DBB redox shuttle protects the LiFePO4-based LIBs with working voltage between 3.4 and 3.5 V. The cycleability of assembled batteries is tested using an Arbin Tester. © 2017 materials Research Society.

关键词： Cathodes

Binding a hopfion in chiral magnet nanodisk

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Liu, Yizhou Lake, Roger K. Zang, Jiadong Department of Electrical and Computer Engineering University of California RiversideCA92521 United States Department of Physics and Materials Science Program University of New Hampshire DurhamNH03824 United States Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sci-ences Beijing100190 China

Hopfions are three-dimensional (3D) topological textures characterized by the integer Hopf invariant QH. Here, we present the realization of a zero-field, stable hopfion spin texture in a magnetic system consisting of a chiral magnet nanodisk sandwiched by two films with perpendicular magnetic anisotropy. The preimages of the spin texture and numerical calculations of QH show that the hop-fion has QH = 1. Furthermore, another non-trivial state that includes a monopole{antimonopole pair (MAP) is also stabilized in this system. By applying an external magnetic field, hopfion and MAP states with the same polarization can be switched between each other. The topological transition between the hopfion and the MAP state involves a creation (annihilation) of the MAP and twist of the preimages. Our work paves the way to study non-trivial 3D topological spin textures and stimulates more investigations in the field of 3D spintronics. Copyright © 2018, The Authors. All rights reserved.

关键词： Textures

Subsurface damage (SSD) assessment in ground Silicon Carbide (SiC)

学校读者我要写书评

暂无评论

Subsurface damage (SSD) assessment in ground Silicon Carbide...

Optical Design and Fabrication, OFT 2017

作者： Lambropoulos, John C. Salzman, Sivan Smith, Thomas R. Xu, Jing Pomerantz, Michael Shanmugam, Prithiviraj Davies, Matthew A. Taylor, Lauren L. Qiao, Jie University of Rochester Materials Science Program United States University of Rochester Dept. of Mechanical Engineering United States Laboratory for Laser Energetics RochesterNY United States University of North Carolina at Charlotte CharlotteNC United States Rochester Institute of Technology Center for Imaging Science RochesterNY United States

We assess subsurface damage in ground Silicon Carbide, by measurement of roughness evolution and material removal rate in sub-aperture finished spots, or by estimates via material property figures of merit or abrasive... 详细信息

ISBN: (纸本)9781943580316

关键词： Silicon carbide

Z2classification for a novel antiferromagnetic topological insulating phase in three-dimensional topological Kondo insulator

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Li, Huan Zhong, Yin Liu, Yu Luo, Hong-Gang Song, Hai-Feng College of Science Guilin University of Technology Guilin541004 China Center for Interdisciplinary Studies Key Laboratory for Magnetism and Magnetic Materials of the MoE Lanzhou University Lanzhou730000 China Institute of Applied Physics and Computational Mathematics Beijing100088 China Software Center for High Performance Numerical Simulation China Academy of Engineering Physics Beijing100088 China Beijing Computational Science Research Center Beijing100084 China

Antiferromagnetic topological insulator (AFTI) is a topological matter that breaks time-reversal symmetry. Since its proposal, explorations of AFTI in strong-correlated systems are still lacking. In this paper, we show for the first time that a novel AFTI phase can be realized in three-dimensional topological Kondo insulator (TKI). In a wide parameter region, the ground states of TKI undergo a second-order transition to antiferromagnetic insulating phases which conserve a combined symmetry of time reversal and a lattice translation, allowing us to derive a Z2-classification formula for these states. By calculating the Z2index, the antiferromagnetic insulating states are classified into (AFTI) or non-topological antiferromagnetic insulator (nAFI) in different parameter regions. On the antiferromagnetic surfaces in AFTI, we find topologically protected gapless Dirac cones inside the bulk gap, leading to metallic Fermi rings exhibiting helical spin texture with weak spin-momentum locking. Depending on model parameters, the magnetic transitions take place either between AFTI and strong topological insulator, or between nAFI and weak topological insulator. By varying some model parameters, we find a topological transition between AFTI and nAFI, driving by closing of bulk gap. Our work may account for the pressure-induced magnetism in TKI compound SmB6, and helps to explore richer AFTI phases in heavyfermion systems as well as in other strong-correlated systems. Copyright © 2018, The Authors. All rights reserved.

关键词： Antiferromagnetism

Reconfigurable mid-infrared hyperbolic metasurfaces using phase-change materials

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Folland, T.G. Fali, A. White, S.T. Matson, J.R. Liu, S. Aghamiri, N.A. Edgar, J.H. Haglund, R.F. Abate, Y. Caldwell, J.D. Department of Mechanical Engineering Vanderbilt University NashvilleTN37212 United States Department of Physics and Astronomy University of Georgia AthensGA30602-2451 United States Department of Physics and Astronomy Vanderbilt University NashvilleTN37235 United States Interdisciplinary Materials Science Program Vanderbilt University NashvilleTN37212 Department of Chemical Engineering Kansas State University ManhattanKS66506 United States

Metasurfaces offer the potential to control light propagation at the nanoscale for applications in both free-space and surface-confined geometries1-3. Existing metasurfaces frequently utilize metallic polaritonic4 elements with high absorption losses5, and/or fixed geometrical designs that serve a single function. Here we overcome these limitations by demonstrating a reconfigurable hyperbolic6 metasurface comprising of a heterostructure of isotopically enriched hexagonal boron nitride (hBN)7-10 in direct contact with the phase-change material (PCM) vanadium dioxide (VO2)11-14. Spatially localized metallic and dielectric domains in VO2 change the wavelength of the hyperbolic phonon polaritons (HPhPs) supported in hBN by a factor 1.6 at 1450cm-1. This induces in-plane launching, refraction and reflection of HPhPs in the hBN, proving reconfigurable control of in-plane HPhP propagation at the nanoscale15. These results exemplify a generalizable framework based on combining hyperbolic media and PCMs in order to design optical functionalities such as resonant cavities, beam steering, waveguiding and focusing with nanometric control. Copyright © 2018, The Authors. All rights reserved.

关键词： III-V semiconductors

Application of free surface synthetic schlieren method in determining surface tension from a light floating object

学校读者我要写书评

暂无评论

Journal of Physics: Conference Series 2019年第1期1380卷

作者： C Pathommapas S Yapo E Seesomboon N Pussadee Master's Degree Program in Teaching Physics Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Science Department Udomdarunee School Sukhothai 52000 Thailand Department of Mechanical Engineering Faculty of Engineering Chiang Mai University Chiang Mai 50200 Thailand Plasma and Beam Physics Research Facility Department of Physics and Materials Science Chiang Mai University Chiang Mai 50200 Thailand Thailand Center of Excellence in physics Commission on Higher Education 328 Si Ayutthaya Road Bangkok 10400 Thailand

Free surface synthetic schlieren (FS-SS) is a liquid surface topography visualization technique relying on apparent dot pattern displacement due to liquid surface deformation. It has gained attention in the fluid visualization field due to its relatively simple and inexpensive setup. One of the most powerful features of the FS-SS technique is the 3D topography of deformed liquid surface, in which submillimeter scale changes can be readily observed in great detail. The visualization of liquid meniscus at the solid interface is proposed in this study to calculate surface tension by equating the surface tension force with weight of light, floating object with circular geometry. It was found that surface tensions of liquids are much greater than anticipated, suggesting that the effect of buoyant force of displaced liquid due to deformed interface cannot be neglected. When the buoyant force is included, the calculated surface tension of liquids are within 10% of the reference values.

关键词：

Room-temperature lasing action in GaN quantum wells in the infrared 1.5 µm region

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Ho, V.X. Al tahtamouni, T.M. Jiang, H.X. Lin, J.Y. Zavada, J.M. Vinh, N.Q. Department of Physics Center for Soft Matter and Biological Physics Virginia Tech BlacksburgVA24061 United States Materials Science & Technology Program College of Arts & Sciences Qatar University Doha2713 Qatar Department of Electrical and Computer Engineering Texas Tech University LubbockTX79409 United States Department of Electrical and Computer Engineering New York University BrooklynNY11201 United States

Large-scale optoelectronics integration is strongly limited by the lack of efficient light sources, which could be integrated with the silicon complementary metal-oxide-semiconductor (CMOS) technology. Persistent efforts continue to achieve efficient light emission from silicon in the extending the silicon technology into fully integrated optoelectronic circuits. Here, we report the realization of room-temperature stimulated emission in the technologically crucial 1.5 µm wavelength range from Er-doped GaN multiple-quantum wells on silicon and sapphire. Employing the well-acknowledged variable stripe technique, we have demonstrated an optical gain up to 170 cm-1 in the multiple-quantum well structures. The observation of the stimulated emission is accompanied by the characteristic threshold behavior of emission intensity as a function of pump fluence, spectral linewidth narrowing and excitation length. The demonstration of room-temperature lasing at the minimum loss window of optical fibers and in the eye-safe wavelength region of 1.5 µm are highly sought-after for use in many applications including defense, industrial processing, communication, medicine, spectroscopy and imaging. As the synthesis of Er-doped GaN epitaxial layers on silicon and sapphire has been successfully demonstrated, the results laid the foundation for achieving hybrid GaN-Si lasers providing a new pathway towards full photonic integration for silicon optoelectronics. Driven by the strong need for cheap and integrable Si-based optoelectronic devices for a wide range of applications, continuing endeavors have been made to develop structures for light emission, modulation, and detection in this material system. Recent breakthroughs including the demonstration of a high-speed optical modulator in Si,1-2 photodetectors3, and waveguides4 have brought the concept of transition from electrical to optical interconnects closer to realization. However, the base for silicon photonics, namely, a group IV la

关键词： Semiconductor quantum wells