IEEE Transactions on Magnetics最新文献

{"title":"Characterization of spatial homogeneous regions in tissues with concordex.","authors":"Kayla C Jackson, A Sina Booeshaghi, Ángel Gálvez-Merchán, Lambda Moses, Tara Chari, Alexandra Kim, Orhan Hosten-Mittermaier, Lior Pachter","doi":"10.1101/2023.06.28.546949","DOIUrl":"10.1101/2023.06.28.546949","url":null,"abstract":"<p><p>The rapid advancement of spatially resolved transcriptomics (SRT) technologies has facilitated exploration of how gene expression varies across tissues. However, identifying spatially variable genes remains challenging due to confounding variation introduced by the spatial distribution of cell types. We introduce a new approach to identifying spatial domains that are homogeneous with respect to cell-type composition that facilitates the decomposition of gene expression patterns by cell-type and spatial variation. Our method, called concordex, is efficient and effective across technological platforms and tissue types, and using several biological datasets we show that it can be used to identify genes with subtle variation patterns that are missed when considering only cell-type variation, or spatial variation, alone. The concordex tool is freely available at https://github.com/pachterlab/concordexR.</p>","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"24 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11275758/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84732967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel OrbiTran Magnetically Geared Rotating Electrical Machine","authors":"Oleg Molokanov","doi":"10.1109/TMAG.2025.3580223","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3580223","url":null,"abstract":"This article presents a novel electrical machine topology with a built-in magnetic gear (MG), combining concepts from cycloidal MGs and rolling-rotor machines (RMMs). It enables electromechanical conversion in both motor and generator modes. To overcome the complex rotation typically associated with cycloidal gears, the high-speed (HS) and low-speed (LS) rotors are mechanically decoupled. The HS rotor performs translational motion along a small orbit, which inspired the name “OrbiTran.” A 2-D FEM model with a gear ratio of 60 was developed, demonstrating a torque density of 114 kN<inline-formula> <tex-math>$cdot $ </tex-math></inline-formula>m/m3 under relatively low thermal load on the stator windings, which typically corresponds to natural convection cooling. It was also demonstrated that the proposed machine can continuously operate at maximum torque density with negligible torque ripples. Since the component of the machine responsible for electromechanical conversion relies on reluctance torque, and PMs are naturally shielded from armature magnetic fields, the proposed device is expected to exhibit a high degree of fault tolerance. Despite its many advantages, proposed topology still inherits significant radial imbalances from the cycloidal MG, and the RMM it is based on.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 8","pages":"1-11"},"PeriodicalIF":2.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mutual Inductance of Multilayer Spiral-Inductor Clusters for Small-Form-Factor Wireless Power Transfer (μWPT)","authors":"Joshua S. Benjestorf;Julio V. Urbina;Akhlesh Lakhtakia","doi":"10.1109/TMAG.2025.3579931","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3579931","url":null,"abstract":"Spiral inductors are commonly used in wireless power transfer (WPT) systems due to their simplicity and low cost, but their large physical size poses challenges for <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>WPT systems (i.e., WPT systems with small form factors). To address these challenges, multilayer spiral-inductor clusters (MSICs) are employed to increase the mutual inductance between the transmitting and receiving couplers for acceptably high power-transfer efficiency. This article uses the Neumann formula, first, to derive an exact analytical expression for the equivalent inductance <inline-formula> <tex-math>$L_{N}^{mathrm { Eq1}}$ </tex-math></inline-formula> of an MSIC of N layers and, second, to conceptualize a mutual inductance <inline-formula> <tex-math>$M_{N}^{dy}(g)$ </tex-math></inline-formula> between two MSICs that are separated by an air gap g and derive an exact analytical expression for it. These novel expressions were verified experimentally within 1% margin of error and can be easily applied to design <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>WPT systems.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 8","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromagnetic Analysis of YASA Axial Flux Motor Using Harmonic Modeling Considering Non-Linear Core Permeability","authors":"Manh-Dung Nguyen;Jun-Won Yang;Duy-Tinh Hoang;Kyung-Hun Shin;Jang-Young Choi","doi":"10.1109/TMAG.2025.3578655","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3578655","url":null,"abstract":"This study presents a 2-D harmonic modeling (HM) approach for analyzing the non-linear permeability of the core in a yokeless and segmented armature (YASA) axial flux motor. The proposed method formulates Maxwell’s equations in cylindrical coordinates using complex Fourier series and the Cauchy product, effectively addressing local saturation effects. To validate the model, a 3-D finite element method (FEM) analysis was conducted, demonstrating good agreement with the proposed approach. In particular, the HM approach reduces computational time by up to 30 times compared to conventional FEM simulations, making it a promising tool for motor pre-design and optimization in high-value applications that require 3-D analysis.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 9","pages":"1-12"},"PeriodicalIF":1.9,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manipulating the FMR Frequency of YIG Nanostrips With Exchange Bias","authors":"Wen Huang;Yong Ren;Xiaoyu Li;Min Chen;Yan Zhang;Fang Xu;Guixiang Liu;Bo Dai","doi":"10.1109/TMAG.2025.3578784","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3578784","url":null,"abstract":"Microwave ferrite devices are now widely utilized across various scenarios, often requiring the application of an external bias field to manipulate their operational frequency. As ferrite devices continue to shrink in size, there is increasing interest in leveraging the exchange bias effect to regulate frequency within a smaller volume. In the study, our research focuses on exploring an optimum method that manipulates the ferromagnetic resonance (FMR) frequency of thin yttrium iron garnet (YIG)/IrMn bilayer nanostrips. Through theoretical analysis and simulations, our model demonstrates the successful adjustability of YIG film’s FMR frequency from 0 to 30 GHz, which offers valuable insights for designing miniaturized, frequency-adjustable microwave ferrite devices.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 8","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Grain Boundary Diffusion on the Coercivity, Thermal Stability, and Magnetization Reversal of Sintered Nd–Fe–B Permanent Magnets","authors":"Suo Bai;Yanrui Shi;Bangchen Li;Jizhong Zhao;Yongfeng Li;Zhubai Li;Qian Zhao;Shilin Luo","doi":"10.1109/TMAG.2025.3578188","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3578188","url":null,"abstract":"Grain boundary diffusion considerably enhances the coercivity of sintered Nd–Fe–B permanent magnets and optimizes their microstructures. Herein, we fabricated these magnets with a nominal composition of Nd30.25Fe68.22M0.59B0.94 (M represents Cu, Co, Zr, Ga, and Al) via powder metallurgy. Terbium fluoride powder served as the diffusion source in grain boundary diffusion. After the diffusion, the coercivity of the magnets substantially increased. Moreover, the temperature coefficient of coercivity (<inline-formula> <tex-math>$beta $ </tex-math></inline-formula>) considerably improved in the temperature range of <inline-formula> <tex-math>$25~^{circ }$ </tex-math></inline-formula>C–<inline-formula> <tex-math>$150~^{circ }$ </tex-math></inline-formula>C. The considerable enhancement in coercivity and its <inline-formula> <tex-math>$beta $ </tex-math></inline-formula> is attributed to the formation of Tb-rich (Nd, Tb)2Fe14B phases with high magnetocrystalline anisotropy in the outer layers of the main phase grains. This optimizes the grain boundary structure and reduces surface defects of the main phase grains during grain boundary diffusion, increasing the coercivity, weakening the exchange coupling effect, and suppressing magnetization reversal. The recoil loops and thermal activation reflect this suppression, possibly owing to the exchange coupling effect among the Nd2Fe14B main phase grains or the (Nd, Tb)2Fe14B main phase grains with a core-shell structure as well as between the core and shell of the (Nd, Tb)2Fe14B main phase grains. These synergistic effects enhance the nucleation field for reverse domains on the main phase surface and reduce the activation volume. Consequently, coercivity is enhanced, effectively suppressing magnetization reversal and thermal fluctuations. This ensures high remanence, thermal stability, and demagnetization resistance in the Nd–Fe–B permanent magnets, thereby enhancing the reliability and efficiency of permanent-magnet motors in long-term operation.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 7","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144536457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topology Optimization of Annular Lorentz Force Actuator for Non-Contact Annular Electromagnetic Stabilized Spacecraft","authors":"Mingxuan Song;He Liao;Zijie Wu;Haoxiang Yuan","doi":"10.1109/TMAG.2025.3578529","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3578529","url":null,"abstract":"As the core actuator to ensure the high-precision attitude control of the non-contact annular electromagnetic stabilized spacecraft, the annular Lorentz force actuator (ALFC) plays a pivotal role in control system due to its advantages of rapid response and high accuracy. This study proposes a topology optimization to transcend the traditional design paradigms. First, a solid isotropic material with penalization (SIMP)-based optimization model is constructed, which incorporating magnetic flux density distribution into the objective function and establishing a material interpolation model for annular magnetic circuits and coil configurations. Second, the method of moving asymptotes (MMAs) algorithm is employed to solve the non-convex optimization problem. Finally, through finite element simulations, the optimization results are quantitatively assessed, ultimately identifying a novel ALFC structure that satisfies both precision and intensity requirements for engineering applications, which provides a novel design paradigm for non-contact annular electromagnetic stabilized spacecraft.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 8","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electronic Interface Design Considerations for Biomagnetic Sensing Using TMR Sensors","authors":"Huxi Wang;Meraj Ahmad;Asfand Tanwear;Negin Ghahremani Arekhloo;Siming Zuo;Kianoush Nazarpour;Hadi Heidari","doi":"10.1109/TMAG.2025.3577734","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3577734","url":null,"abstract":"We present a comprehensive design methodology for the electronic interface of a tunneling magnetoresistance (TMR) sensor, which plays a crucial role in determining the detectivity of biomagnetic measurement systems. A theoretical noise model is developed that links sensor detectivity to key design parameters such as the Wheatstone bridge configuration, sensor biasing, and analog front-end (AFE) noise performance. The model is based on a detailed characterization of the TMR sensor and accurately predicts the influence of bias voltage and resistance mismatches on the power supply rejection ratio (PSRR). It shows that the full Wheatstone bridge configuration achieves superior detectivity and that the PSRR can degrade from near-infinite values to approximately 28 dB under a background magnetic field of <inline-formula> <tex-math>$5~mu $ </tex-math></inline-formula> T. Guided by this model, the sensor system is optimized in terms of bridge configuration, bias conditions, and AFE design. Experimental validation confirms a detectivity of 7.4 pT/<inline-formula> <tex-math>$surd $ </tex-math></inline-formula> Hz at 1 Hz and an integrated rms noise of 20 pT within the 5–100 Hz band, under both near-zero and <inline-formula> <tex-math>$5~mu $ </tex-math></inline-formula> T magnetic fields. These results surpass those of previously reported TMR-based sensor systems operating in similar frequency bands and under comparable working conditions. The findings highlight the importance of a systematic and integrated approach to electronic interface design for TMR sensors, which supports the development of biomagnetic sensing systems capable of operating without extensive magnetic shielding.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 8","pages":"1-12"},"PeriodicalIF":2.1,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dimensionless Analysis of Axial Magnetic Force and Stiffness in Cylindrical Permanent Magnets and Coils","authors":"Kai Meng;Wei Yuan;Yangkai Chen;Xidong Liu;Fengxiang Shao;Yuxi Liu","doi":"10.1109/TMAG.2025.3577540","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3577540","url":null,"abstract":"This article establishes an equivalent model between cylindrical permanent magnets and solenoids. Based on the magnetic charge theory and Coulomb’s model, an expression for the axial magnetic force is derived, and then the dimensionless axial magnetic force formula. Through further differentiation, the dimensionless axial stiffness formula is obtained. An in-depth analysis is conducted on the impact of dimensionless parameters on axial stiffness. The process of dimensionless calculations eliminates interference caused by differences in unit systems, revealing the intrinsic relationship between magnetic stiffness and the geometric and material properties of the magnets. This provides a theoretical basis for the optimization of electromagnetic device design and holds extensive application value in both engineering and scientific research fields.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 7","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144536517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Sensitive Direct Measurement of Magnetostriction and Stress Response in Near-Zero Magnetostrictive Microwires","authors":"Javier Moya;Manuel Vázquez","doi":"10.1109/TMAG.2025.3577435","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3577435","url":null,"abstract":"The evaluation of magnetostriction in amorphous alloy materials, particularly in the form of microwires, has traditionally relied on indirect methods utilizing inverse magnetoelastic effects to determine the saturation magnetostriction constant, <inline-formula> <tex-math>$lambda _{mathrm {s}}$ </tex-math></inline-formula>. In this study, we report direct magnetostriction measurements using a home-made apparatus capable of determining the engineering magnetostriction, <inline-formula> <tex-math>$lambda _{mathrm {e}}$ </tex-math></inline-formula>, with high sensitivity down to than <inline-formula> <tex-math>$delta l/l_{o}= 10^{-9}$ </tex-math></inline-formula> as a function of the applied field, <inline-formula> <tex-math>$lambda _{mathrm {e}}(H$ </tex-math></inline-formula>), and its stress-dependent, <inline-formula> <tex-math>$lambda _{mathrm {e}}(sigma $ </tex-math></inline-formula>), and magnetization, <inline-formula> <tex-math>$lambda _{mathrm {e}}(M$ </tex-math></inline-formula>), behaviors. Measurements were conducted on in-water-quenched amorphous microwires, including Co-based microwires with vanishing magnetostriction, as well as in a highly magnetostrictive microwire. In addition, the indirect method was used to calculate saturation magnetostriction constant, <inline-formula> <tex-math>$lambda _{mathrm {s}}$ </tex-math></inline-formula>, using the complementary hysteresis loops under applied stress. For Fe-rich Fe75Si10 B15 microwires, <inline-formula> <tex-math>$lambda _{mathrm {s}}= 31.2times 10^{-6}$ </tex-math></inline-formula> was determined. In contrast, for Co-rich microwires, the (Co94Fe6)15Si15B10 alloy exhibited near-zero positive magnetostriction with <inline-formula> <tex-math>$lambda _{mathrm {s}}= 9.7times 10^{-8}$ </tex-math></inline-formula>, while (Co95Fe5)15Si15B10 displayed a slight negative magnetostriction <inline-formula> <tex-math>$lambda _{mathrm {s}}= - 17times 10^{-8}$ </tex-math></inline-formula>. The behavior of magnetostrictive strain under mechanical stress in near-zero magnetostrictive alloys, as observed from direct measurements, shows significant differences compared to indirect measurements found in the literature. Direct measurement of magnetostriction in amorphous microwires provides the magnetostriction value of the material according to its stress state, essential for accurately quantifying magnetostriction in sensors during operation, ensuring more precise and dependable results.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 8","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}