Results 21 to 30 of about 9,159 (190)

Giant Tunability of Individual Magnetic Skyrmion Size via an Oscillating Local Magnetic Field

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Magnetic skyrmions hold great promise as memory and computing elements in future spintronic devices. Despite the demonstration of various devices, techniques for addressable and high‐precision manipulation of individual skyrmions remain scarce.
Cai‐Hong Xie   +13 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  

The Research and Design of Coil Tuning Module in MRI [PDF]

open access: yes, 2016
在成像过程中,射频线圈的工作状态对成像质量影响很大。射频线圈的共振频率和阻抗随着样品的放入会发生改变,造成信噪比和Q值的下降影响成像的质量,而产生的信号反射严重时会损坏功率模块,所以每次成像前后都需对射频线圈进行调谐。传统的调谐采用的是手动操作、上位机显示的方法,操作不便捷,速度较慢。设计一个便于观察的手动调谐检测装置是一个改进的方案,而使用自动调谐不仅不需要人的参与,而且对调谐速度和精度都有一个大的提升。 本文首先回顾了核磁共振的历史和发展,对核磁共振现象及磁共振成像机理进行了阐述 ...
戴奇成
core  

Composite‐Field Annealing Enables Superior High‐Temperature Noise Stability in Fluxgate Sensors With Co‐Rich Amorphous Microwires

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Fluxgate sensors with Co‐rich amorphous microwires, widely used for their low noise in magnetic field measurements, encounter significant challenges in high‐temperature environments such as well drilling and geological exploration. Prolonged thermal aging degrades the performance of Co‐rich amorphous microwires, resulting in increased noise ...
Lining Pan   +10 more
wiley   +1 more source

长宁地区岩石圈磁场磁偶极子反演研究

open access: yesDizhen xuebao
四川长宁地区平均点距间隔2 km的952个测点测得的岩石圈磁场空间分布结果显示,长宁背斜内东西部存在显著的磁场分布差异,且该差异可能与地震活动区域相关,例如:背斜内部对应岩石圈磁场正值区域,背斜边界对应负值区域;背斜的西北边界区域对应最显著的岩石圈磁场负值,背斜东北侧以岩石圈磁场正值分布为主,背斜南侧以岩石圈磁场负值为主。基于上述岩石圈磁场数据,我们构建了区域磁偶极子反演的技术途径以开展磁偶极子源的反演研究。具体途径为:将化极后的长宁背斜岩石圈磁场进行快速傅里叶变换 ...
Xiaotao Wu, Bin Chen, Chao Dong
doaj   +1 more source

Study on Spatiotemporally Encoded Multi-slice Ultrafast Magnetic Resonance Imaging [PDF]

open access: yes, 2016
单扫描磁共振成像技术凭借其良好的时间分辨率,近年来在扩散成像、实时动态三维成像、功能成像等生物医学领域得到广泛应用。在单扫描磁共振成像方法中,回波平面成像(EPI)是最常用的一种方法,但其在高场条件下,对磁场不均匀及化学位移效应十分敏感。基于时空编码的单扫描磁共振成像新方法对不均匀磁场及化学位移伪影有很好的鲁棒性,并延续了EPI良好的时间分辨率。尽管具有这一优势,但时空编码方法使用的线性扫频脉冲(Chirp脉冲)特定吸收率(SAR)较大,在多层成像中,过大的SAR值将限制其临床应用。为了减少SAR值 ...
张婷
core  

Multifunctionality of Magnetic La(Fe, Si/Al)13‐Based Materials: Negative Thermal Expansion and Magnetocaloric Effect

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT In recent years, the field of magnetic materials has witnessed a paradigm shift from single‐function applications to multifunctional integration, driven by the growing demand for smart materials in advanced technologies. Among various magnetic systems, La(Fe, Si/Al)13‐series materials have emerged as particularly promising candidates due to ...
Irfan Liaquat   +2 more
wiley   +1 more source

纵磁结构真空灭弧室的三维磁场数值分析

open access: yesGaoya dianqi, 1999
根据单积分法原理编制了一套三维磁场计算软件,对杯状纵磁、1/2匝线圈纵磁、四极纵磁三种结构的真空灭弧室自生纵向磁场进行了三维数值分析,给出磁场的总体分布以及几个主要参数对磁场分布的影响,并且对其中两种结构的磁场进行实际测量,验证了该软件计算的准确性.
付军   +4 more
doaj  

Investigation on optimal thermoeconomic and thermodynamic performances of the refrigeration cycles using ferromagnetic or Gd-based material as the working substance [PDF]

open access: yes, 2016
当今社会,能源紧缺和环境污染问题日益突出,探寻节能环保的新制冷技术正吸引着越来越多的注意力。具有高效节能、绿色环保、噪音小、结构紧凑的室温磁制冷技术是一种很有潜力的新一代制冷技术的备选。目前,室温磁制冷仍有几大指标需要突破。一是提高制冷机的制冷功率,二是提高制冷机的制冷温跨,三是提高制冷机的热经济性能。当今室温磁制冷发展的两大方向:其一是探索具有高磁热特性的室温磁制冷材料,其二是研制制冷性能指标优的室温磁制冷机。本学位论文是要在提高室温磁制冷机循环的热力学性能和热经济性能方面作出新的有益贡献 ...
徐志超
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

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