Magnetic Technology Research Articles

Development And Application of Magnetic Storage Technology

Magnetic storage technology plays an important role in modern information storage and is the main way of modern information storage. The basic principle is to define the different magnetization states of the magnetic medium as "1" and "0" in the binary, and to realize the storage of information by changing the magnetization state of the magnetic medium. This paper summarizes the basic principle of magnetic storage technology, the characteristics of longitudinal magnetic recording and perpendicular magnetic recording, and their respective advantages. At the same time, this paper also studies the structure, advantages, and development trend of hard disk drives and magnetic random-access memory based on magnetic storage technology. For the frontier of magnetic memory technology, this paper focuses on the physical properties of magnetic Skyrmions and the possibility of magnetic Skyrmions in magnetic memory devices. For the memory using magnetic Skyrmions, topological Hall effect and magnetoresistive effect can be used to complete the writing and reading of information. Finally, this paper is expected to review the importance of magnetic storage technology.

Design, modeling, and validation of a 0.5 kWh flywheel energy storage system using magnetic levitation system

The flywheel energy storage system (FESS) has excellent power capacity and high conversion efficiency. It could be used as a mechanical battery in the uninterruptible power supply (UPS). The magnetic suspension technology is used in the FESS to reduce the standby loss and improve the power capacity. First, the whole system of the FESS with the magnetic levitation system is introduced, and the control diagrams of the charging/discharging processes are developed. Moreover, the force modeling of the magnetic levitation system, including the axial thrust-force permanent magnet bearing (PMB) and the active magnetic bearing (AMB), is conducted, and results indicate that the magnetic forces could stably levitate the flywheel (FW) rotor. The stator part and the FW rotor are analyzed using the FEM model, and the results could satisfy the requirements on stress and strength of the FESS at the rated speed. Then, the control models are established to accomplish the rapid charging/discharging functions of the FESS. Finally, experiments are performed to test the charging/discharging ability, and the results show that an excellent control current could enhance the charging/discharging efficiency so the stable DC link voltage could be outputted at the discharge process. Therefore, the test results prove that the designed FESS could be used as an auxiliary power supply for the UPS when the grid power fails.

Impact of Magnetic Technology for Mitigation Salinity Water Stress on Faba Bean (Vicia Faba L) Growing in Sandy Soil

Impact of Magnetic Technology for Mitigation Salinity Water Stress on Faba Bean (Vicia Faba L) Growing in Sandy Soil

Magnetically Powered Microrobotic Swarm for Integrated Mechanical/Photothermal/Photodynamic Thrombolysis.

Current thrombolytic drugs exhibit suboptimal therapeutic outcomes and potential bleeding risks due to their limited circulation time, inadequate thrombus penetration, and off-target biodistribution. Herein, a photosensitizer-loaded, red cell membrane-encapsuled multiple magnetic nanoparticles aggregate is successfully developed for integrated mechanical/photothermal/photodynamic thrombolysis. Red cell membrane coating endows magnetic particles with prolonged blood circulation and superior biocompatibility. Under a preset rotating magnetic field (RMF), the aggregate with asymmetric magnetic distribution initiates rolling motion toward the blood clot interface, and because of magnetic dipole-dipole interactions, the aggregate tends to self-assemble into longer, flexible chain-like microrobotic swarm with powerful mechanical stir forces, thereby facilitating thrombus penetration and mechanical thrombolysis. Moreover, precise magnetic control enables targeted photosensitizer accumulation, allowing effective conversion of near-infrared (NIR) light into heat and reactive oxygen species (ROS) for thrombus phototherapy. In thrombolysis assays, the weight of thrombi is massively reduced by ≈90%. The work presents a safer and more promising combination of magnetic microrobotic technology and phototherapy for multi-modality thrombolysis.

Magnetization dynamics in skyrmions due to high-speed carrier injections from Dirac half-metals.

Recent developments in the magnetization dynamics in spin textures, particularly skyrmions, offer promising new directions for magnetic storage technologies and spintronics. Skyrmions, characterized by their topological protection and efficient mobility at low current density, are increasingly recognized for their potential applications in next-generation logic and memory devices. This study investigates the dynamics of skyrmion magnetization, focusing on the manipulation of their topological states as a basis for bitwise data storage through a modified Landau-Lifshitz-Gilbert equation (LLG). We introduce spin-polarized electrons from a topological ferromagnet that induce an electric dipole moment that interacts with the electric gauge field within the skyrmion domain. This interaction creates an effective magnetic field that results in a torque that can dynamically change the topological state of the skyrmion. In particular, we show that these torques can selectively destroy and create skyrmions, effectively writing and erasing bits, highlighting the potential of using controlled electron injection for robust and scalable skyrmion-based data storage solutions.

Force-electric characteristics of model rock-filled concrete under uniaxial compression with different curing ages and rock-filled ratios

By analyzing the force-electric properties of rock-filled concrete under uniaxial compression, the precursor information and characteristics of deformation and failure of rock-filled concrete can be mastered, and the reliability and safety of rock-filled concrete structures at an early age can be ensured. This study investigated four variations of model rock-filled concrete, each with a distinct rock-filled ratio. Using the two-electrode alternating current test method, we analyzed the electrical resistivity properties of rock-filled concrete under uniaxial compression at various curing ages (1 d, 3 d, 7 d, 14 d, and 28 d). Additionally, the microscopic pore structure was examined using low-field nuclear magnetic resonance technology. The results showed that with increasing curing age or rock-filled ratio, the compressive strength and electrical resistivity of rock-filled concrete showed a nonlinear growth trend. In contrast, the porosity showed a nonlinear decrease, with the internal pore structure gradually becoming more refined. A mathematical model was established to describe the electrical resistivity of rock-filled concrete at various curing ages and rock-filled ratios. During uniaxial compression, the electrical resistivity of rock-filled concrete followed a pattern of rapid decline, slow decline, stable, and slow increase with strain. These phases corresponded to the development of internal pores and cracks and changes in the crack resistance performance of the rockfill skeleton in the concrete. Moreover, a mathematical equation was formulated to elucidate the relationship among the damage variable, the rock-filled ratio, and the electrical resistivity of model rock-filled concrete, thereby enabling the prediction of the extent of damage to the model rock-filled concrete under stress conditions.

Magnetic properties and large low-field magnetocaloric effect of RFe2Si2 (R = Ho, Tm) compounds

Nowadays, magnetic refrigerant technology has drawn much attention for its environmental friendliness. Those magnetic materials possessing giant low-field magnetocaloric effect (MCE) performance are of great importance for practical applications, especially at low temperatures. Herein, we present a detailed study on polycrystalline magnetocaloric compounds HoFe2Si2 and TmFe2Si2. HoFe2Si2 exhibits a transition from antiferromagnetic to paramagnetic phase at 2.2 K, while no long-range magnetic ordering is observed in TmFe2Si2 even temperature down to 2 K. For both compounds, they showed large low-field magnetic entropy change (−ΔSM) with the peak values of 10.6 and 7.9 J kg−1 K−1 under field change of 0–2 T for HoFe2Si2 and TmFe2Si2, respectively, which is comparable or even larger than some low-temperature magnetocaloric materials. In addition, the characteristic of second-order magnetic transitions of both compounds were confirmed on basis of Arrott plots and mean-field theory criterion. The low magnetic ordering temperatures, large low-field MCE performance along with the feature of second order phase transition for HoFe2Si2 and TmFe2Si2 indicate that both compounds are promising candidate for magnetic refrigerant materials at liquid helium temperature.

Enhanced exchange bias in all-oxide heterostructures with cation-ordered ferrimagnetic double-perovskite

The realization and control of exchange bias (EB) are highly desirable for spintronic applications. All-oxide heterostructures comprised of ferromagnetic and antiferromagnetic/multiferroic oxides provide an ideal platform to enable the electric-field control of EB, promising for energy-efficient memory and logic devices. However, the low block temperature (TB) and small bias field (HEB) hinder further advances towards room-temperature applications. Here, we report an alternative approach to enhance the interface-induced EB by using ferrimagnetic double-perovskite with B-site cation ordering. In heterostructures comprised of double-perovskite Sr2FeReO6 (SFRO) and LaFeO3 (LFO), a high TB (about 250 K) and large HEB are observed, which is significantly larger than the counterparts with LFO and ferromagnetic oxides. Further analysis suggests that the cation-ordering and ferrimagnetic spin structure of the double-perovskite could contribute significantly to the enhanced exchanged bias when interfacing with G-type antiferromagnets. Our results open a new avenue for developing all-oxides heterostructures for future magnetic technologies.

G-quadruplex embedded in semi-CHA reaction combined with invasive reaction for label-free detection of single nucleotide polymorphisms

G-quadruplex/thioflavin T (G4/THT) is one of the ideal label-free fluorescent light-emitting elements in the field of biosensors due to its good programmability and adaptability. However, the unsatisfactory luminous efficiency of single-molecule G4/THT limits its more practical applications. Here, we developed a G4 embedded semi-catalytic hairpin assembly (G4-SCHA) reaction by rationally modifying the traditional CHA reaction, and combined with the invasive reaction, supplemented by magnetic separation technology, for label-free sensitive detection of single nucleotide polymorphisms (SNPs). The invasive reaction enabled specific recognition of single-base mutations in DNA sequences as well as preliminary signal cycle amplification. Then, magnetic separation was used to shield the false positive signals. Finally, the G4-SCHA was created for secondary amplification and label-free output of the signal. This dual-signal amplified label-free biosensor has been shown to detect mutant targets as low as 78.54 fM. What's more, this biosensor could distinguish 0.01 % of the mutant targets from a mixed sample containing a large number of wild-type targets. In addition, the detection of real and complex biological samples also verified the practical application value of this biosensor in the field of molecular design breeding. Therefore, this study improves a label-free fluorescent light-emitting element, and then proposes a simple, efficient and universal label-free SNP biosensing strategy, which also provides an important reference for the development of other G4/THT based biosensors.

The structural, electronic and magnetic properties of [formula omitted] anti-perovskite

A comprehensive exploration of the structural, electronic, and magnetic attributes of anti-perovskite Fe3ZnC carbides was carried out using Density Functional Theory (DFT) and Monte Carlo Simulation (MCS). These anti-perovskite materials possess a unique structure where cation and anion positions are interchanged within the perovskite framework. Our study involves a comparative analysis of the electronic band structures and density of states (DOS) for Fe3ZnC, considering prior theoretical and experimental research. Understanding these anti-perovskite materials' band structures and DOS is pivotal for their effective utilization in magnetic sensors and magnetic refrigeration applications. Our results indicate that Fe3ZnC displays ferromagnetic metallic behavior, particularly when applying the Generalized Gradient Approximation (GGA). Notably, there is a significant overlap between the valence (VB) and conduction (CB) bands. Furthermore, MCS predicts a second-order ferromagnetic-to-paramagnetic transition in the anti-perovskite Fe3ZnC compound, characterized by a notably high Curie temperature. These insights advance our understanding of these materials, paving the way for their effective utilization in magnetic technologies.

Research Progress of Magnetic Flocculation in Water Treatment

As people’s material quality of life continues to improve, water resources become subjected to varying degrees of contamination. As one of the most commonly utilised agents in water treatment, a flocculant exhibits a diverse range of forms and a vast scope of applications. However, the application of flocculants gives rise to a series of issues, including the use of large doses, the formation of sludge, the difficulty of recycling flocculants, and other concerns. The development of new flocculation technology has become a crucial step in enhancing the purification of wastewater and reducing environmental pollution. Magnetic flocculation can be classified into two main categories: magnetic seeds flocculation and magnetic flocculation. This paper presents an overview of the factors influencing magnetic flocculation, including the type of magnetic seeds, magnetic seeds particle size, and other pertinent considerations. Furthermore, the classification of magnetic flocculants in the process of magnetic flocculation is discussed. This includes the types of magnetic flocculant, namely, inorganic composite magnetic flocculants, organic composite magnetic flocculants, and biological composite magnetic flocculants. Inorganic composite magnetic flocculants are inexpensive and simple to produce; however, their dosage is considerable, and the resulting floc is not tightly formed, which impairs the efficacy of flocculation. The use of organic composite magnetic flocculants requires a smaller dosage and exhibits a strong flocculating ability; however, it may possess toxic properties and potentially cause harm to the water body. The biological composite magnetic flocculant exhibits high efficiency and no pollution, yet it is subject to stringent environmental conditions, displays poor stability, and is applicable to a relatively limited range of treatment scenarios. Furthermore, the integration of magnetic flocculation technology with other techniques is classified and summarised in diverse contexts, and the prospective research focus and direction of magnetic flocculants are proposed.

Exploring Weak Magnetic Signal Characteristics of Pipeline Welds: Insights into Stress Non-Uniformity Effects.

Weak magnetic detection technology can detect stress concentration areas in ferromagnetic materials. However, the stress non-uniform characteristics of pipeline welds lead to significant differences in stress distribution range and values between inner wall welds and outer wall welds. This discrepancy makes it crucial to further evaluate the impact of stress non-uniformity on magnetic signals. To study the magnetic signal characteristics under the influence of residual stress in weld seams, a magneto-mechanical analytical model was established based on the magnetic charge theory and the distribution characteristics of residual stress in the weld seam. The magneto-mechanical relationship and magnetic signal distribution characteristics at the inner and outer wall welds of the pipeline are calculated. Furthermore, the effects of different excitation intensities on the amplitude growth characteristics of magnetic signals are analyzed and compared. To verify the analysis model, weld detection experiments with different excitation intensities were designed. The results show that both the peak-to-valley values of the normal component and the peak values of the tangential component of the outer wall weld are lower than those of the inner wall weld. Conversely, the peak-to-valley width of the normal component and the peak width of the tangential component are greater than those of the inner wall weld. Additionally, the rate of increase in weak magnetic signal amplitude decreases in a first-order exponential relationship with increasing excitation intensity. The average decay rates of the normal and tangential component amplitude growth rates for the inner wall weld are 34.03% and 27.9%, respectively, while for the outer wall weld, they are 31.75% and 28.01%, respectively. This study contributes to the identification and quantitative assessment of weak magnetic signals in inner and outer wall welds.

Towards High-Quality MRI Reconstruction With Anisotropic Diffusion-Assisted Generative Adversarial Networks And Its Multi-Modal Images Extension.

Recently, fast Magnetic Resonance Imaging reconstruction technology has emerged as a promising way to improve the clinical diagnostic experience by significantly reducing scan times. While existing studies have used Generative Adversarial Networks to achieve impressive results in reconstructing MR images, they still suffer from challenges such as blurred zones/boundaries and abnormal spots caused by inevitable noise in the reconstruction process. To this end, we propose a novel deep framework termed Anisotropic Diffusion-Assisted Generative Adversarial Networks, which aims to maximally preserve valid high-frequency information and structural details while minimizing noises in reconstructed images by optimizing a joint loss function in a unified framework. In doing so, it enables more authentic and accurate MR image generation. To specifically handle unforeseeable noises, an Anisotropic Diffused Reconstruction Module is developed and added aside the backbone network as a denoise assistant, which improves the final image quality by minimizing reconstruction losses between targets and iteratively denoised generative outputs with no extra computational complexity during the testing phase. To make the most of valuable MRI data, we extend its application to support multi-modal learning to boost reconstructed image quality by aggregating more valid information from images of diverse modalities. Extensive experiments on public datasets show that the proposed framework can achieve superior performance in polishing up the quality of reconstructed MR images. For example, the proposed method obtains average PSNR and mSSIM values of 35.785dB and 0.9765 on the MRNet dataset, which are at least about 2.9dB and 0.07 higher than those from the baselines.

Perpendicular magnetization switching of RuO2(1 0 0)/[Pt/Co/Pt] multilayers

Current-induced perpendicular magnetization switching holds great potential for high-density magnetic storage technology. We report the growth of perpendicularly magnetized [Pt/Co/Pt] multilayers on a collinear altermagnet RuO2(100) thin films. The current-induced effective magnetic field was determined through anomalous Hall effect loop measurements with current applied along the [010] or [001] direction of RuO2(100). Magnetization switching was successfully achieved with the assistance of an in-plane magnetic field. Furthermore, by adjusting the nominal top Pt thickness of the [Pt/Co/Pt] multilayers, we could change the polarity of the current-induced magnetization switching, demonstrating an effective manipulation of spin polarization direction in RuO2/[Pt/Co/Pt]. These results provide a practical approach to the development of perpendicular magnetic devices based on RuO2 and have advanced the study of spin-splitting altermagnets.

Fluid Dynamics Performance and Energy Consumption Analysis of a New-Type of Reciprocating Plate Column Based on Electro-Permanent Magnet Technology

Fluid Dynamics Performance and Energy Consumption Analysis of a New-Type of Reciprocating Plate Column Based on Electro-Permanent Magnet Technology

Fusion PCAM R-CNN of Automatic Segmentation for Magnetic Flux Leakage Defects.

Magnetic leakage detection technology plays an important role in the long-oil pipeline. Automatic segmentation of defecting images is crucial for the detection of magnetic flux leakage (MFL) works. At present, accurate segmentation for small defects has always been a difficult problem. In contrast to the state-of-the-art MFL detection methodologies based on convolution neural network (CNN), an optimization method is devised in our study by integrating mask region-based CNN (Mask R-CNN) and information entropy constraint (IEC). To be precise, the principal component analysis (PCA) is utilized to improve the feature learning and network segmentation ability of the convolution kernel. The similarity constraint rule of information entropy is proposed to be inserted into the convolution layer in the Mask R-CNN network. The Mask R-CNN optimizes the convolutional kernel with similar weights or higher similarity, meanwhile, the PCA network reduces the dimension of the feature image to reconstruct the original feature vector. As such, the feature extraction of MFL defects is optimized in the convolution check. The research results can be applied in the field of MFL detection.

Non-destructive inspection method for egg freshness evaluation via low-field nuclear magnetic resonance technology

Non-destructive inspection method for egg freshness evaluation via low-field nuclear magnetic resonance technology

Investigation on the influences of CaO on tar of biomass model compounds by Boltzmann-Monte Carlo-Percolation (BMCP) model

CaO have been widely used in biomass thermal conversion processes to deal with tar of biomass. The influences of the CaO on the function groups or intermediates of the bio tars are crucial because strategies on refining bio tars can be determined. The pyrolysis experiments of three typical model compounds, lignin, cellulose, hemicellulose, are carried out in a multi-stage tube followed by a cold trap. The influence of CaO can be analyzing the products distribution and components obtained from Nuclear Magnetic Resonance and Gas Chromatography-Mass Spectrometry technologies with and without CaO-loaded honeycombs. As the adsorbed matters on CaO-loaded honeycombs are hardly to be analyzed, the Boltzmann-Monte Carlo-Percolation model is introduced to make further investigations on the possible influence of CaO. The experimental results suggest that generations of unsaturated structures are inhibited by CaO, and the comparison of simulation and experimental results suggest that aliphatic carbon-centered radicals rather than oxygen-centered radicals are adsorbed and stabilized by CaO.

Study on early hydration and pore structure evolution of cement paste containing graphene oxide

Graphene oxide (GO) significantly enhances cement hydration. This study investigates the effects of GO on the early hydration and pore structure evolution of cement paste by examining its impact on the setting time and mechanical properties of cement-based materials. In situ monitoring of the hydration process and microstructural changes was conducted using low-field nuclear magnetic resonance technology. The findings reveal that GO's nucleation effect accelerates cement hydration, reducing the setting time and increasing both the hydration rate and degree. Moreover, hydration products utilize GO as a template, leading to adjusted morphologies and enhanced interlinking of C–S–H gels. This results in a marked reduction in porosity and a denser microstructure within the cement paste. Consequently, the early mechanical properties of the cement paste are improved, with a significant increase in flexural strength observed at 72 hours. These results suggest that GO, which is cost-effective, size-controllable and suitable for mass production, holds great potential for applications in cement-based materials.

Development of a new technological scheme of the carousel milking platform based on the principles of magnetic levitation

The Carousel, the most capital–intensive and loaded milking unit, is a rotating platform that carries a large mechanical load. Its own weight, combined with the weight of the animals being moved, can reach 1200 kg per milking place or more. To reduce friction in the wheeled systems of high-loaded vehicles, large-sized assemblies and mechanisms of machinery and equipment, including agricultural machinery and aggregates, the use of magnetic suspension technology is promising. The research was carried out in order to develop a new technological scheme of a levitating rotating milking platform Carousel based on the principles of magnetic levitation. The creation of a fundamentally new resource-saving design of the Carousel milking platform based on the principles of magnetic levitation in order to increase its reliability and reduce operating costs due to the exclusion of wear on the propellers of the rail-wheel system is possible. A new scheme of a rotating milking platform Carousel using permanent magnet magnetic suspension technology without the use of wheel thrusters is proposed. Its force calculation was performed in the main mode of steady motion with the platform fully filled with animals and partially filled at the beginning and end of the milking cycle of animals, obtaining basic equations for determining the necessary repulsive forces in horizontal and vertical magnetic assemblies providing magnetic levitation (suspension) and lateral stabilization (centering) of the rotating platform.