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Spontaneous magnetization and magnetic domain texture of strontium hexaferrite in equilibrium state

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Rare Metals 2022年第9期41卷 3019-3026页

作者： Dan Liu Si-Da Jiang Li-Chen Wang Ruo-Shui Liu Ming Zhang tong-yun zhao Feng-Xia Hu Ji-Rong Sun Bao-Gen Shen School of Artificial Intelligence Beijing Technology and Business UniversityBeijing100048China Space Environment Simulation Research Infrastructure Harbin Institute of TechnologyHarbin150001China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341000China School of Physics Inner Mongolia University of Science and TechnologyBaotou014010China State Key Laboratory of Magnetism Institute of PhysicsChinese Academy of SciencesBeijing100190China

The spontaneous magnetization and equilibrium domain of SrFeOunder zero external field by micromagnetic simulation and experimental measurements were *** was found that the magnetic moment distribution was extremely sensitive to the grain size of strontium *** critical diameter from single-domain to multi-domain can be controlled by changing the thickness and diameter,which is the key to improve the permanent magnet properties.

关键词： properties. magnetization magnetic

Composition design for (PrNd-La-Ce)2Fe(14)B melt-spun magnets by machine learning technique

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Chinese Physics B 2018年第4期27卷 460-464页

作者： Rui Li Yao Liu Shu-Lan Zuo tong-yun zhao Feng-Xia Hu Ji-Rong Sun Bao-Gen Shen State Key Laboratory of Magnetism Institute of Physics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

Data-driven technique is a powerful and efficient tool for guiding materials design,which could supply as an alternative to trial-and-error *** order to accelerate composition design for low-cost rare-earth permanent magnets,an approach using composition to estimate coercivity（H（cj）） and maximum magnetic energy product（BH）（max） via machine learning has been applied to（PrNd–La–Ce）2Fe（14）B melt-spun magnets.A set of machine learning algorithms are employed to build property prediction models,in which the algorithm of Gradient Boosted Regression Trees is the best for predicting both H（cj） and（BH）（max）,with high accuracies of R^2= 0.88 and 0.89,*** the best models,predicted datasets of H（cj） or（BH）max in high-dimensional composition space can be *** these virtual datasets could provide efficient guidance for materials design,and facilitate the composition optimization of 2：14：1 structure melt-spun *** with magnets＇ cost performance,the candidate cost-effective magnets with targeted properties can also be accurately and rapidly *** data analytics,which involves property prediction and composition design,is of great time-saving and economical significance for the development and application of La Ce-containing melt-spun magnets.

关键词： permanent magnet materials design machine learning property prediction

High performance RE–Fe–B sintered magnets with high-content misch metal by double main phase process

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Chinese Physics B 2020年第10期29卷 494-500页

作者： Yan-Li Liu Qiang Ma Xin Wang Jian-Jun Zhou tong-yun zhao Feng-Xia Hu Ji-Rong Sun Bao-Gen Shen State Key Laboratory of Magnetism Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Science Inner Mongolia University of Science and TechnologyBaotou 014010China University of Chinese Academy of Sciences Beijing 100049China

Double main phase process is applied to fabricate [(Pr, Nd)1 – xMMx]13.8FebalM1.5B5.9 (x = 0.5 and 0.7;M = Cu, Al, Co, and Nb) sintered magnets with high misch metal (MM) content. In comparison to the magnets by single main phase process, the enhanced magnetic properties have been achieved. For magnets of x = 0.7, Hcj increases to 371.9 kA/m by 60.5%, and (BH)max is significantly enhanced to 253.3 kJ/m3 by 56.9%, compared with those of the single main phase magnets of the same nominal composition. In combination with minor loops and magnetic recoil curves, the property improvement of magnets with double main phase method is well explained. As a result, it is demonstrated that double main phase technology is an effective approach to improve the permanent magnetic properties of MM based sintered magnets.

关键词： misch maetal double main phase process magnetic properties coercivity

Magnetic properties of misch-metal partially substituted Nd–Fe–B magnets sintered by dual alloy method

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Chinese Physics B 2018年第7期27卷 521-526页

作者： Jie-Fu Xiong Rong-Xiang Shang Yan-Li Liu Xin zhao Wen-Liang Zuo Feng-Xia Hu Ji-Rong Sun tong-yun zhao Ren-Jie Chen Bao-Gen Shen State Key Laboratory of Magnetism Institute of Physics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China

The misch-metal （MM） partially substituted Nd-Fe-B sintered magnets were fabricated by the dual alloy method, and the crystal structure, microstructure, and magnetic properties were analyzed comprehensively. X-ray diffraction （XRD） reveals that the increasing content of the MM has an inconsiderable effect on the crystallographic alignment of the magnets. Grains of the two main phases are uniformly distributed, and slightly deteriorate on the grain boundary. Due to the diffusion between the adjacent grains, the MM substituted Nd-Fe-B magnets contain three types of components with different Ce/La concentrations. Moreover, the first-order reversal curve （FORC） diagram is introduced to analyze the magnetization reversal process, coercivity mechanism, and distribution of reversal field in magnetic samples. The analysis indicates that there are two major reversal components, corresponding to the two different main phases. The domain nucleation and growth are determined to be the leading mechanism in controlling the magnetization reversal processes of the magnets sintered by the dual alloy method.

关键词： misch-metal first order reversal curve the dual alloy method magnetization reversal process

Lorentz transmission electron microscopy studies on topological magnetic domains

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Chinese Physics B 2018年第6期27卷 47-61页

作者： Li-Cong Peng Ying Zhang Shu-Lan Zuo Min He Jian-Wang Cai Shou-Guo Wang Hong-Xiang Wei Jian-Qi Li tong-yun zhao Bao-Gen Shen Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

Lorentz transmission electron microscopy（TEM） is a powerful tool to study the crystal structures and magnetic domain structures in correlation with novel physical properties. Nanometric topological magnetic configurations such as vortices, bubbles, and skyrmions have received enormous attention from the viewpoint of both fundamental science and potential applications in magnetic logic and memory devices, in which understanding the physical properties of magnetic nanodomains is essential. In this review article, several magnetic imaging methods in Lorentz TEM including the Fresnel and Foucault modes, electron holography, and differential phase contrast（DPC） techniques are discussed, where the novel properties of topological magnetic domains are well addressed. In addition, in situ Lorentz TEM demonstrates that the topological domains can be efficiently manipulated by electric currents, magnetic fields, and temperatures, exhibiting novel phenomena under external fields, which advances the development of topological nanodomain-based spintronics.

关键词： in situ Lorentz TEM magnetic vortices magnetic bubbles magnetic skyrmions

Hydrogen sulfide reduces oxidative stress in Huntington's disease via Nrf2

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Neural Regeneration Research 2025年第6期20卷 1776-1788页

作者： Zige Jiang Dexiang Liu Tingting Li Chengcheng Gai Danqing Xin Yijing zhao Yan Song Yahong Cheng tong Li Zhen Wang Department of Physiology School of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong ProvinceChina Department of Medical Psychology and Ethics School of Basic Medicine SciencesCheeloo College of MedicineShandong UniversityJinanShandong ProvinceChina Department of Neurosurgery Surgery Qingdao Municipal HospitalQingdaoShandong ProvinceChina

The pathophysiology of Huntington's disease involves high levels of the neurotoxin quinolinic acid. Quinolinic acid accumulation results in oxidative stress, which leads to neurotoxicity. However, the molecular and cellular mechanisms by which quinolinic acid contributes to Huntington's disease pathology remain unknown. In this study, we established in vitro and in vivo models of Huntington's disease by administering quinolinic acid to the PC12 neuronal cell line and the striatum of mice, respectively. We observed a decrease in the levels of hydrogen sulfide in both PC12 cells and mouse serum, which was accompanied by down-regulation of cystathionine β-synthase, an enzyme responsible for hydrogen sulfide production. However, treatment with NaHS(a hydrogen sulfide donor) increased hydrogen sulfide levels in the neurons and in mouse serum, as well as cystathionine β-synthase expression in the neurons and the mouse striatum, while also improving oxidative imbalance and mitochondrial dysfunction in PC12 cells and the mouse striatum. These beneficial effects correlated with upregulation of nuclear factor erythroid 2-related factor 2 expression. Finally, treatment with the nuclear factor erythroid 2-related factor 2inhibitor ML385 reversed the beneficial impact of exogenous hydrogen sulfide on quinolinic acid-induced oxidative stress. Taken together, our findings show that hydrogen sulfide reduces oxidative stress in Huntington's disease by activating nuclear factor erythroid 2-related factor 2,suggesting that hydrogen sulfide is a novel neuroprotective drug candidate for treating patients with Huntington's disease.

关键词： apoptosis cystathionine-β-synthase nuclear factor erythroid 2-related factor 2 Huntington's disease hydrogen sulfide mitochondrion neuroplasticity oxidative stress quinolinic acid reactive oxygen species

Regulation and function of endoplasmic reticulum autophagy in neurodegenerative diseases

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Neural Regeneration Research 2025年第1期20卷 6-20页

作者： Xiu-yun zhao De-En Xu Ming-Lei Wu Ji-Chuan Liu Zi-Ling Shi Quan-Hong Ma Department of Neurology and Clinical Research Center of Neurological Disease the Second Affiliated Hospital of Soochow UniversitySuzhouJiangsu ProvinceChina Institute of Neuroscience&Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases Soochow UniversitySuzhouJiangsu ProvinceChina Department of Neurology Jiangnan University Medical CenterWuxiJiangsu ProvinceChina

The endoplasmic reticulum,a key cellular organelle,regulates a wide variety of cellular *** reticulum autophagy,one of the quality control systems of the endoplasmic reticulum,plays a pivotal role in maintaining endoplasmic reticulum homeostasis by controlling endoplasmic reticulum turnover,remodeling,and *** this review,we briefly describe the endoplasmic reticulum quality control system,and subsequently focus on the role of endoplasmic reticulum autophagy,emphasizing the spatial and temporal mechanisms underlying the regulation of endoplasmic reticulum autophagy according to cellular *** also summarize the evidence relating to how defective or abnormal endoplasmic reticulum autophagy contributes to the pathogenesis of neurodegenerative *** summary,this review highlights the mechanisms associated with the regulation of endoplasmic reticulum autophagy and how they influence the pathophysiology of degenerative nerve *** review would help researchers to understand the roles and regulatory mechanisms of endoplasmic reticulum-phagy in neurodegenerative disorders.

关键词： autophagy endoplasmic reticulum endoplasmic reticulum autophagy endoplasmic reticulum quality control system endoplasmic reticulum receptors endoplasmic reticulum-associated degradation neurodegeneration neurodegenerative disease selective autophagy unfolded protein response

Impact of Startup Strategy and Buffer Tank Volume on the Compressor Inlet State for a 3-MW sCO2 Brayton Cycle

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Journal of Thermal Science 2025年第1期34卷 159-175页

作者： zhao Decai WANG Bo Key Laboratory of Advanced Energy and Power Institute of Engineering Thermophysics(IET)Chinese Academy of Sciences (CAS) University of Chinese Academy of Sciences

The supercritical carbon dioxide（sCO2） Brayton cycle system has become an emerging and highly promising method of thermal power conversion due to its efficiency advantage,system compactness,and excellent adaptability of the heat *** the low carbon sCO2Brayton cycle testbed with cycle output power approaching 3 MW,a relatively detailed dynamic simulation model of the entire system is constructed to explore the dynamic response characteristics of the system with different startup strategies and different buffer tank volumes during the startup *** simulation results indicate that the smaller the volume of the buffer tank,the more rapid and obvious the parameter fluctuation in the buffer tank during the *** the allowable relative deviation limit of density is 5%,then the ratio of the buffer tank volume to the volume of the entire closed loop should not be lower than 36.80%.The strategy of simultaneous temperature and speed increase during turbine bypass start can effectively reduce the fluctuation of compressor inlet parameters and reach the steady-state more *** paper provides the recommended matching table for the opening of the turbine bypass valve（TBV） and the main regulating valve（MGV） to reduce the parameter fluctuation during the bypass *** effectiveness of the proposed turbine bypass and bypass switching startup strategy is verified by simulation,which may be used as a reference for test bench's future debugging and operation.

关键词： buffer tank dynamic characteristic dynamic model sCO2 Brayton cycle startup strategy

Reverse modulation of defect density of Ce-MOF-808 by solventassisted ligand exchange for dicyclopentadiene hydrogenation

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Science China Chemistry 2025年

作者： Danfeng zhao Fajie Hu Rushuo Li Xinmeng Xu zhaokun Wang Zuoshuai Xi Jun tong Xiubing Huang Ge Wang Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory of Function Materials for Molecule & Structure Construction School of Materials Science and Engineering University of Science and Technology Beijing

Defect engineering is a pivotal strategy for tailoring the electronic structure and physicochemical properties of catalysts, yet the straightforward manipulation of defect density in porous materials presents a current challenge. In this work, we achieved precise control over the coordination unsaturated site（CUS） content and pore architecture of Ce-MOF-808 by employing 2-fluorobenzoic acid（2-FBA） as a modifier. Leveraging the p Kadisparities among three ligands（1,3,5-tricarboxylic benzoic acid,formic acid, and 2-FBA）, we preserved the spn topology of Ce-MOF within an aqueous system, while realizing partial substitution of the auxiliary ligands and saturation of the CUS. The amount of 2-FBA was negatively correlated with the number of ligand defects, and the consequent decrease in Ce3+content and the increase in the number of ligand linkages also induced crystal structure transformation. The modulation of the defect structure was correlated with the catalytic performance of dicyclopentadiene（DCPD） hydrogenation reaction, in which Ce-MMF0.15, constructed by the modulation of 0.15 mol amount of 2-fluorobenzoic acid, exhibited an optimal ligand defect density and micro-mesoporous structure, enabling almost complete conversion of DCPD at 100 ℃ and 2 MPa. This article also elucidates the correlation between the regulation of defect density and the accessibility of frustrated Lewis pair（FLP） active sites, guiding the application of novel porous intrinsic FLP materials in hydrogenation catalysis.

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