Results 11 to 20 of about 4,798 (162)

Configuration Optimization Design of Magnetic Circuit for Large Magnetostrictive Devices Based on TbDyFe Alloy

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Reliable operation of high‐performance magnetostrictive devices, composed of the giant magnetostrictive material (GMM), that is, the TbDyFe alloy, critically depends on an optimally tailored bias magnetic field. Sufficient intensity and uniformity are essential to induce the ideal initial strain in the GMM, enabling peak reciprocating output ...
Jinan Yu   +12 more
wiley   +1 more source

The FPGA Design of 0.5T Joint MRI System Console [PDF]

open access: yes, 2015
核磁共振成像是目前医学影像中应用最为广泛的新成像技术之一,原理是在磁场中利用线圈发出射频脉冲激发质子发生共振,从而产生磁共振信号,采集并传至计算机进行数据处理最终成像。核磁共振成像技术能够快速、准确获得人体各部位阻值症状信息,具有对比度高、成像参数多、无电离辐射伤害等优点。 磁共振成像仪器主要由主控计算机、控制台、射频功率放大器、梯度功率放大器、射频线圈、梯度线圈、磁体和温控等模块组成。其中,控制台是整个仪器的核心模块,它负责系统中各个模块间的通信、射频脉冲信号和梯度信号的产生 ...
姚凯文
core  

Fermi Surface Structure Revealed by Quantum Oscillations in Half‐Heusler Semimetal LuAuSn

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The Fermi surface structure in the half‐Heusler semimetallic compound LuAuSn was systematically investigated using quantum oscillation studies of high‐quality single crystals and first‐principles calculations. Clear bulk quantum oscillation signals were observed for multiple complementary physical properties, including magnetization, Hall ...
Yue Lu   +12 more
wiley   +1 more source

开关柜工频磁场计算及壳体屏蔽效能分析

open access: yesGaoya dianqi, 2023
文中基于电磁场基本理论,建立了开关柜工频磁场数学模型,采用有限元法对开关柜的磁感应强度进行了计算,分析了壳体、壳体厚度和磁导率等对开关柜磁感应强度分布和屏蔽效能的影响,并研究了开关柜柜外母排长度对磁感应强度分布的影响,结果表明:开关柜外壳和隔板对工频磁场具有明显的屏蔽作用,增大壳体磁导率和厚度均可提高开关柜整体的屏蔽效能,但当壳体磁导率大于1 000和厚度超过3 mm时,屏蔽效能增长幅度较小;柜外母排长度对开关柜周围磁场分布影响较小,但对柜体顶部磁场分布的影响较大 ...
王岩   +4 more
doaj  

Numerical Simulation And Experiment Study On Magnetoacoustic Emission with Magnetic Induction [PDF]

open access: yes, 2015
铝合金板材具有高强度、低密度、强耐腐蚀、高断裂韧性和良好的高低温特性等优点,是制造宇宙飞船、运载火箭、飞机、舰船、坦克、装甲车和高速列车的主要材料。然而,由于加工工艺限制,铝合金板材在生产过程中不可避免地存在分层、夹杂、裂纹和氧化膜等缺陷。无损检测技术是一种在不破坏待测物材质与性能前提下实现构件质量检测的技术,目前已在许多领域成为确保产品质量和可靠性的强制性措施。 本文研究的感应式磁声发射无损检测方法是利用线圈在导体感应出的涡流在静态磁场的作用下会受到洛仑兹力的作用使导体发生机械振动,进而产生磁声信号 ...
李超
core  

Study of the pitch change of carbon coils during their growth [PDF]

open access: yes, 2012
In the present paper, carbon coils (CCs) were prepared by CVD. Their morphology, particularly pitch changes of the carbon coils prepared in different conditions were observed.
Dupré, L.   +5 more
core   +1 more source

Highly Anisotropic TbCo11Ti: Phase Evolution, Microstructure and Magnetic Properties

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Among the 1:12‐type compounds, TbCo11Ti stands out due to its high Curie temperature and pronounced magnetocrystalline anisotropy. However, its magnetic behavior at room temperature and its phase evolution process have not been clearly established.
Wei Chen   +11 more
wiley   +1 more source

太阳风局部加速的磁流体力学过渡特征 [PDF]

open access: yes, 1981
本文讨论了轴对称磁力线管中太阳风从亚声速和亚阿尔文速度加速到超声速和超阿尔文速度的过程。考虑到流动和场的二维效应以后,除去临界声速线 M~2=1 以外,还有临界阿尔文速线 M_A~2=1 和M~2+M_A~2=1。这时,磁力线管中存在三次过渡,使磁流体力学方程组的类型从椭圆型变为双曲型,再变为椭圆型,最后变为双曲型。由于日冕中的典型声速和阿尔文速度具有相同的量级,而且人们对磁力线管的急剧膨胀很有兴趣,这就需要讨论二维磁流体力学方程组的自(冫合)解 ...
胡文瑞
core  

Enhanced Low‐Frequency Microwave Absorption and Corrosion Resistance of FeSiAl Using Low‐Melting‐Point Glass Phase Coatings

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT This study developed a FeSiAl@LMPGP composite material to address the demand for low‐frequency electromagnetic absorption. Through controllable heat treatment, FeSiAl particles and PbO nanoparticles self‐assembled into a high‐density Mott–Schottky heterointerface structure, which exhibited a significant built‐in electric field (BIEF) effect ...
Yuqi Wang   +5 more
wiley   +1 more source

地磁场中竖直套管周围磁场分布规律研究

open access: yesShiyou jixie, 2015
目前钻调整井、加密井和丛式井已经成为各油田增产增效的重要措施。井网密度的增大导致井间距的减小,邻井套管产生的磁干扰影响愈发显著。为此,采用圆柱坐标系,建立了套管在地磁场磁化的磁场模型,从水平磁化场和竖直磁化场2方面研究了地磁场中竖直套管周围磁场分布规律。研究结果表明,半径小于0.5 m的范围内,水平磁化场Hh检测出区别,Hh的极大值出现在0°和180°方位线上,随着半径增大,磁场强度迅速衰减为地磁场大小,Hh的极小值出现在90°和270°方位线上,随着半径增大,磁场强度迅速增大为地磁场大小 ...
张端瑞   +4 more
doaj  

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