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Rotating magnetic field inhibits Aβ protein aggregation and alleviates cognitive impairment in Alzheimer’s disease mice
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作者 Ruo-Wen Guo Wen-Jing Xie +5 位作者 Biao Yu Chao Song Xin-Miao Ji Xin-Yu Wang Mei Zhang Xin Zhang 《Zoological Research》 SCIE CSCD 2024年第4期924-936,共13页
Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation... Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment. 展开更多
关键词 lzheimer’s disease Rotating magnetic field Amyloid-β Cognitive function Alzheimer’s disease animal models
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Earth’s Magnetic Field—The Key to Global Warming 被引量:1
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作者 Bjarne Lorenzen 《Journal of Geoscience and Environment Protection》 2019年第7期25-38,共14页
It is commonly known that the climate debate suffers due to a lack of knowledge about the cause and effect relationship between a number of climatic temperature variations that have occurred in history without being a... It is commonly known that the climate debate suffers due to a lack of knowledge about the cause and effect relationship between a number of climatic temperature variations that have occurred in history without being able to blame human emission of greenhouse gas in any way. Only when we are willing to give up the idea that there is a geodynamo deep inside of the Earth being responsible for the Earth’s magnetic field and when we get back to the idea that the origin of the magnetic field is simply ferromagnetic, will it be possible to establish two different cause and effect connections that are suitable to explain why there is an acknowledged coincidence between climatic temperature variations and an intensive, proportional variation in the strength of the Earth’s magnetic field. Such insight may easily prove to be decisive at a time when many people can no longer differentiate between politics, mass hysteria, presumptions and actual knowledge. When there are requirements that a solution to climatic temperature variations must contain the solution to the coincidence mentioned, two possible scenarios exist. The one possibility (although not very likely) that is suitable to solve the mysterious coincidence is that mainly the northern part of the Atlantic Ocean is heated from within (from the interior of the Earth) and that variations in the Earth’s emission of heat cause primarily all of Europe to have witnessed warm winters for decades. The one possible cause and effect connection may (in theory) be that inner heat in the Earth’s crust can loosen frozen, ferromagnetic structures, thereby drive the Earth’s ferromagnetic, magnetic field to restructure and be reorganised from periodically being a chaotic, magnetic field to periodically being a well-structured, ferromagnetic field. The connection between magnetism and thermal impact is already commonly known. The other and somewhat more likely cause and effect connection is building on Henrik Svensmark’s (and teams) theory that says that variations in the cosmic radiation reaching the Earth depend on the strength of the Sun’s magnetic field and that this radiation contributes to creating aerosols, thereby variations in the cloud formation. Solar storms contribute to temporarily strengthening the Earth’s magnetic field. The question is whether these contributions could also periodically have a long-term effect on the Earth’s magnetic field. In that case, this may explain the reason for the above-mentioned coincidence. 展开更多
关键词 earths magnetic field GEODYNAMO Global WARMING
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Large magnetic-field-induced strains in rare earth polycrystalline Ni-Mn-Ga 被引量:2
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作者 ZHAOZengqi WUShuangxia +3 位作者 WANGFangshu WANGQiang JIANGLiping WANGXinlin 《Rare Metals》 SCIE EI CAS CSCD 2004年第3期241-245,共5页
The magnetic-field-induced strains (MFIS) of polycrystallineNi_(50)Mn_(29)Ga_(21) alloys containing Tb were studied. A large MFIS of -1.10% was obtained undercompressi ve prestress conditions. The addition of Tb can f... The magnetic-field-induced strains (MFIS) of polycrystallineNi_(50)Mn_(29)Ga_(21) alloys containing Tb were studied. A large MFIS of -1.10% was obtained undercompressi ve prestress conditions. The addition of Tb can fine the crystal grains, enhance thebending strength obviously, and make MFIS increase further, indicating that a moderate amount of Tbdoes not hinder twin boundary motion and it conversely makes the material more practical. 展开更多
关键词 metal materials magnetic-field-induced strain rare earths Ni-Mn-Ga alloy
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Secular Effect of Geomagnetic Field and Gravitational Waves on Earth’s Satellite Orbits
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作者 M. H. A. Youssef 《Journal of Applied Mathematics and Physics》 2019年第8期1697-1705,共9页
In this work we study the perturbation and the change in the orbital elements due to the earth’s magnetic field and the gravitational waves. The acceleration components are derived in the radial, transverse to it and... In this work we study the perturbation and the change in the orbital elements due to the earth’s magnetic field and the gravitational waves. The acceleration components are derived in the radial, transverse to it and normal to the orbital plane. The equation for the rates of variation of the elements is formed and solved to find the secular variation in the element for polar and equatorial satellites. 展开更多
关键词 GRAVITATIONAL WAVEs earths magnetic field PERTURBATIONs ORBITAL MECHANICs
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Interplay of iron and rare-earth magnetic order in rare-earth iron pnictide superconductors under magnetic field
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作者 杨雷雷 刘大勇 +1 位作者 陈东猛 邹良剑 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期446-453,共8页
The magnetic properties of iron pnictide superconductors with magnetic rare-earth ions under strong magnetic field are investigated based on the cluster self-consistent field method. Starting from an effective Heisenb... The magnetic properties of iron pnictide superconductors with magnetic rare-earth ions under strong magnetic field are investigated based on the cluster self-consistent field method. Starting from an effective Heisenberg model, we present the evolution of magnetic structures on magnetic field in RFeAsO(R = Ce, Pr, Nd, Sm, Gd, and Tb) and RFe_2As_2(R =Eu) compounds. It is found that spin-flop transition occurs in both rare-earth and iron layers under magnetic field, in good agreement with the experimental results. The interplay between rare-earth and iron spins plays a key role in the magneticfield-driven magnetic phase transition, which suggests that the rare-earth layers can modulate the magnetic behaviors of iron layers. In addition, the factors that affect the critical magnetic field for spin-flop transition are also discussed. 展开更多
关键词 iron pnictide superconductors RARE-earth magnetic field spin-flop transition
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Dependence of Gravity Induced Absorption Changes on the Earth’s Magnetic Field as Measured during Parabolic Flight Campaigns
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作者 Werner Schmidt 《Journal of Modern Physics》 2013年第11期1546-1553,共8页
Various spectroscopic experiments performed on the AIRBUS ZERO G—located in Bordeaux, France—in the years 2002 to 2012 exhibit minute optical reflection/absorption changes (GIACs) as a result of gravitational change... Various spectroscopic experiments performed on the AIRBUS ZERO G—located in Bordeaux, France—in the years 2002 to 2012 exhibit minute optical reflection/absorption changes (GIACs) as a result of gravitational changes between 0 and 1.8 g in various biological species such as maize, oats, Arabidopsis and particularly Phycomyces sporangiophores. During a flight day, the AIRBUS ZERO G conducts 31 parabolas, each of which lasts about three minutes including a period of 22 s of weightlessness. So far, we participated in 11 parabolic flight campaigns including more than 1000 parabolas performing various kinds of experiments. During our campaigns, we observed an unexplainable variability of the measuring signals (GIACs). Using GPS-positioning systems and three dimensional magnetic field sensors, these finally were traced back to the changing earth’s magnetic field associated with the various flight directions. This is the first time that the interaction of gravity and the Earth’ magnetic field in the primary induction process in living system has been observed. 展开更多
关键词 MDWs(Micro Dual Wavelength spectrometer) GIAC(Gravity Induced Absorption Change) AIRBUs-300-ZERO-G Parabolic Flight Micro-and Hypergravity Three Dimensional earths magnetic field Global Positioning system(GPs) Google earth
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Chaotic Motion Analysis for a Coupled Magnetic-Flow-Mechanical Model of the Rectangular Conductive Thin Plate
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作者 Xinzong Wang Xiaofang Kang Qingguan Lei 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第11期1749-1771,共23页
The chaotic motion behavior of the rectangular conductive thin plate that is simply supported on four sides by airflow andmechanical external excitation in a magnetic field is studied.According to Kirchhoff’s thin pl... The chaotic motion behavior of the rectangular conductive thin plate that is simply supported on four sides by airflow andmechanical external excitation in a magnetic field is studied.According to Kirchhoff’s thin plate theory,considering geometric nonlinearity and using the principle of virtualwork,the nonlinearmotion partial differential equation of the rectangular conductive thin plate is deduced.Using the separate variable method and Galerkin’s method,the system motion partial differential equation is converted into the general equation of the Duffing equation;the Hamilton system is introduced,and the Melnikov function is used to analyze the Hamilton system,and obtain the critical surface for the existence of chaos.The bifurcation diagram,phase portrait,time history response and Poincarémap of the vibration system are obtained by numerical simulation,and the correctness is demonstrated.The results showthatwhen the ratio of external excitation amplitude to damping coefficient is higher than the critical surface,the system will enter chaotic state.The chaotic motion of the rectangular conductive thin plate is affected by different magnetic field distributions and airflow. 展开更多
关键词 Rectangular conductive thin plate CHAOTIC AIRFLOW magnetic field Melnikov function Galerkin’s method
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Ultra-high-field magnetic resonance:Why and when? 被引量:1
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作者 Ewald Moser 《World Journal of Radiology》 CAS 2010年第1期37-40,共4页
This paper briefly summarizes the development of magnetic resonance imaging and spectroscopy in medicine.Aspects of magnetic resonancephysics and-technology relevant at ultra-high magnetic fields as well as current li... This paper briefly summarizes the development of magnetic resonance imaging and spectroscopy in medicine.Aspects of magnetic resonancephysics and-technology relevant at ultra-high magnetic fields as well as current limitations are highlighted.Based on the first promising studies,potential clinical applications at 7 Tesla are suggested.Other aims are to stimulate awareness of the potential of ultra-high field magnetic resonance and to stimulate active participation in much needed basic or clinical research at 7 Tesla or higher. 展开更多
关键词 Alzheimer’s disease Brain tumors CARTILAGE Functional magnetic REsONANCE imaging magnetic REsONANCE magnetic REsONANCE spectroscopy Multiple sCLEROsIs Ultra-high field magnetic REsONANCE methods
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Changes of auditory evoked magnetic fields in patients after acute cerebral infarction using magnetoencephalography 被引量:1
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作者 Zhanyong Sun Chunfeng Song +7 位作者 Jilin Sun Ling Li Yanhong Dong Jianhua Wang Jie Wu Wenzhu Cui Yujin Wu Peiyuan Lv 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第24期1906-1913,共8页
Auditory evoked magnetic fields were recorded from 15 patients with acute cerebral infarction and 11 healthy volunteers using magnetoencephalography.The auditory stimuli of 2 kHz pure tone were binaurally presented wi... Auditory evoked magnetic fields were recorded from 15 patients with acute cerebral infarction and 11 healthy volunteers using magnetoencephalography.The auditory stimuli of 2 kHz pure tone were binaurally presented with an interstimulus interval of 1 second.The intensity of stimuli was 90 dB and the stimulus duration was 8 ms.The results showed that the M100 was the prominent response, peaking approximately 100 ms after stimulus onset in all subjects.It originated from the area close to Heschl’s gyrus.In the patient group,the peak latency of M100 responses was significantly prolonged,and the mean strength of equivalent current dipole was significantly smaller in the affected hemisphere.The three-dimensional inter-hemispheric difference of the M100 positions was increased in the patient group.Our experimental findings suggested that impairment of cerebral function in patients with acute ischemic stroke can be detected using magnetoencephalography with the higher spatial resolution and temporal resolution.Magnetoencephalography could provide objective and sensitive indices to estimate auditory cortex function in patients with acute cerebral infarction. 展开更多
关键词 acute cerebral infarction cerebral ischemia magnetOENCEPHALOGRAPHY auditory evoked magnetic fields equivalent current dipole Heschl’s gyrus brain functional impairment nerve injury regeneration neural regeneration
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Extremely low frequency electromagnetic fields stimulation modulates autoimmunity and immune responses:a possible immuno-modulatory therapeutic effect in neurodegenerative diseases 被引量:2
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作者 Fabio Guerriero Giovanni Ricevuti 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第12期1888-1895,共8页
Increasing evidence shows that extremely low frequency electromagnetic fields(ELF-EMFs) stimulation is able to exert a certain action on autoimmunity and immune cells. In the past, the efficacy of pulsed ELFEMFs in ... Increasing evidence shows that extremely low frequency electromagnetic fields(ELF-EMFs) stimulation is able to exert a certain action on autoimmunity and immune cells. In the past, the efficacy of pulsed ELFEMFs in alleviating the symptoms and the progression of multiple sclerosis has been supported through their action on neurotransmission and on the autoimmune mechanisms responsible for demyelination. Regarding the immune system, ELF-EMF exposure contributes to a general activation of macrophages, resulting in changes of autoimmunity and several immunological reactions, such as increased reactive oxygen species-formation, enhanced phagocytic activity and increased production of chemokines. Transcranial electromagnetic brain stimulation is a non-invasive novel technique used recently to treat different neurodegenerative disorders, in particular Alzheimer's disease. Despite its proven value, the mechanisms through which EMF brain-stimulation exerts its beneficial action on neuronal function remains unclear. Recent studies have shown that its beneficial effects may be due to a neuroprotective effect on oxidative cell damage. On the basis of in vitro and clinical studies on brain activity, modulation by ELF-EMFs could possibly counteract the aberrant pro-inflammatory responses present in neurodegenerative disorders reducing their severity and their onset. The objective of this review is to provide a systematic overview of the published literature on EMFs and outline the most promising effects of ELF-EMFs in developing treatments of neurodegenerative disorders. In this regard, we review data supporting the role of ELF-EMF in generating immune-modulatory responses, neuromodulation, and potential neuroprotective benefits. Nonetheless, we reckon that the underlying mechanisms of interaction between EMF and the immune system are still to be completely understood and need further studies at a molecular level. 展开更多
关键词 electromagnetic fields Alzheimer's disease transcranial magnetic stimulation autoimmunity immunomodulation
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Martensitic Transformation and Magnetic-Field-Induced Strain in Ni-Mn-Ga-RE (RE=Tb, Sm) Alloys 被引量:4
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作者 郭世海 张羊换 +2 位作者 赵增祺 李健靓 王新林 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第5期632-635,共4页
The effects of microamount additions of RE (Tb, Sm) on martensitic transition, the magnetic-field-induced strain and the bending strength of highly textured polycrystalline Ni_(48)Mn_(33)Ga_(19) alloy were investigate... The effects of microamount additions of RE (Tb, Sm) on martensitic transition, the magnetic-field-induced strain and the bending strength of highly textured polycrystalline Ni_(48)Mn_(33)Ga_(19) alloy were investigated. The experimental results show that the addition of RE elements decreases the martensitic transformation temperature and the Curie temperature. But the bending strength of Ni-Mn-Ga-RE (RE=Tb, Sm) alloys increases remarkably because of the grain refinement. As a result, Ni-Mn-Ga-RE alloys will be applied practically with higher reliability and stability due to favorable plasticity and toughness. In addition, the replacement of small amounts Ga by Tb or Sm decreases the magnetic-field-induced strain of the alloys at room temperature. 展开更多
关键词 metal materials Ni-Mn-Ga alloy martensitic transformation magnetic-field-induced strain shape memory alloy rare earths
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Effects of Magnetic Field on Fracture of Al-Li Alloy Containing Ce rium
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作者 刘兵 王西宁 陈铮 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第1期69-72,共4页
The effects of magnetic field on fracture feature and microstructure of Al-Li a lloys containing Ce were investigated. Experiment results show that the fracture features and the microstructures are changed with the m... The effects of magnetic field on fracture feature and microstructure of Al-Li a lloys containing Ce were investigated. Experiment results show that the fracture features and the microstructures are changed with the magnetic field. The fract ure surface of the alloys is mainly quasi-cleavage without applying magnetic fi eld. With a magnetic field, the fracture of quasi-cleavage changes to more second ary cracks and less quasi-cleavage plates on fracture surface. Grains become thinner and uniform with applying magnetic field. The influence of magnetic f ield on atom diffusion was discussed. 展开更多
关键词 metal materials magnetic field fracture f eature microstructure few-body physics rare earths
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Relationship Between Magnetic Field-Induced Entropy Change and Magnetic Field
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作者 Dong Qiaoyan Zhang Hongwei +3 位作者 Shen Juelian Sun Jirong He Shuli Shen Baogen 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第4期I0011-I0011,共1页
The ingots with the composition oi LaFe13-x Six ( 1.2 〈 x 〈 2.2) were prepared by arc-melting, and subsequently homogenized by annealing for a long time. The sample was mainly composed of a single NaZn13-type phas... The ingots with the composition oi LaFe13-x Six ( 1.2 〈 x 〈 2.2) were prepared by arc-melting, and subsequently homogenized by annealing for a long time. The sample was mainly composed of a single NaZn13-type phase. The dependence of magnetization on the magnetic field was measured at different temperatures for LaFe13- xSix ( 1.2 ≤ x ≤ 2.2) compound, and the entropy change (△S) was calculated using Maxwell relation. The variation of AS with H was discussed according to both the Landau second-order phase transition theory and the scaling law under mean-field approximation. The results show that the relation of △S ∝ H^2/3 is satisfied for the LaFe13-x Six compounds. The parameters obtained by the simulation of peak value of entropy change can be used to determine the degree of first-order magnetic phase transition. The present work may be useful for the research of the magnetic refrigeration. 展开更多
关键词 La(Fe si 13 compound entropy change magnetic field Curie temperature rare earths
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Electric, Magnetic and Gravitation Field of the Earth
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作者 Alexander Ivanchin 《Journal of Geoscience and Environment Protection》 2017年第12期66-79,共14页
In the article a theory of the origin of the magnetic field of the Earth (MFE) caused by the phenomenon of ferromagnetism in the mantle has been proposed. Due to the pressure the mantle substance changes from the diel... In the article a theory of the origin of the magnetic field of the Earth (MFE) caused by the phenomenon of ferromagnetism in the mantle has been proposed. Due to the pressure the mantle substance changes from the dielectric state to the metal one. As a result, there appear free electrons, whose magnetic moment leads to the formation of the magnetic field of the Earth. The above phase transition manifests itself by the Moho. It is proposed that not only the measurement of the dipole component of the magnetic field be made, as it is done nowadays, but also that of the quadrupole and octapole components. These measurements will provide information on the origin of the MFE and its distribution through the Earth volume. It has been shown that the electric field of the Earth (EFE) cannot be produced by the movement of the mobile charges in principle. The EFE is produced by bound electrons. A hypothesis has been proposed that the electric constant has different values for the proton-proton, electron-electron and proton-electron interactions. The relative value of this difference is quite small of the order of 10-28 and, for this reason, it has not been found experimentally. The difference in the interaction results in gravitation, the attraction of the electroneutral masses. Gravitation is a variety of electrostatics. As a result of this difference, the electrons are gravitationally stronger attracted to the electroneutral mass than the protons. The gravitating mass attracts surplus electrons, which lead to the formation of the EFE. In the atmosphere around the negatively charged Earth there are positive charges screening the Earth charge. This state is equilibrium;the positive charge of the atmosphere cannot penetrate into the condensed substance and neutralize the surplus negative charge of the Earth, which would increase the system energy. 展开更多
关键词 magnetic field of the earth ELECTRIC field of the earth GRAVITATIONAL field of the earth
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Pressure Tuning of Magnetism and Drastic Increment of Thermal Conductivity under Applied Magnetic Field in HgCr_2S_4
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作者 顾川川 陈绪亮 +4 位作者 沈晨 凌浪生 皮雳 杨昭荣 张裕恒 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第6期137-140,共4页
HgCr2S4 is a typical compound manifesting competing ferromagnetic (FM) and antiferromagnetic (AFM) exchanges as well as strong spin-lattice coupling. Here we study these effects by intentionally choosing a combina... HgCr2S4 is a typical compound manifesting competing ferromagnetic (FM) and antiferromagnetic (AFM) exchanges as well as strong spin-lattice coupling. Here we study these effects by intentionally choosing a combination of magnetization under external hydrostatic pressure and thermal conductivity at various magnetic fields. Upon applying pressure up to 10 kbar at 1 kOe, while the magnitude of magnetization reduces progressively, the AFM ordering temperature TN enhances concomitantly at a rate of about 1.5 K/kbar. Strikingly, at lO kOe the field polarized FM state is found to be driven readily back to an AFM one even at only 5kbar. In addition, the thermal conductivity exhibits drastic increments at various fields in the temperature range with strong spin fluctuations, reaching about 30% at 50 kOe. Consequently, the results give new experimental evidence of spin-lattice coupling. Apart from the colossal magnetoeapacitance and colossal magnetoresistance reported previously, the findings here may enable new promising functionalities for potential applications. 展开更多
关键词 of on as Is AFM in Pressure Tuning of magnetism and Drastic Increment of Thermal Conductivity under Applied magnetic field in HgCr2s4
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High-precision chaotic radial basis function neural network model:Data forecasting for the Earth electromagnetic signal before a strong earthquake
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作者 Guocheng Hao Juan Guo +2 位作者 Wei Zhang Yunliang Chen David AYuen 《Geoscience Frontiers》 SCIE CAS CSCD 2022年第1期364-373,共10页
The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and irregularities.The change tendency may be related to the occurrence of earthquake disasters... The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and irregularities.The change tendency may be related to the occurrence of earthquake disasters.Forecasting of the underlying intensity trend plays an important role in the analysis of data and disaster monitoring.Combining chaos theory and the radial basis function neural network,this paper proposes a forecasting model of the chaotic radial basis function neural network to conduct underlying intensity trend forecasting by the Earth’s natural pulse electromagnetic field signal.The main strategy of this forecasting model is to obtain parameters as the basis for optimizing the radial basis function neural network and to forecast the reconstructed Earth’s natural pulse electromagnetic field data.In verification experiments,we employ the 3 and 6 days’data of two channels as training samples to forecast the 14 and 21-day Earth’s natural pulse electromagnetic field data respectively.According to the forecasting results and absolute error results,the chaotic radial basis function forecasting model can fit the fluctuation trend of the actual signal strength,effectively reduce the forecasting error compared with the traditional radial basis function model.Hence,this network may be useful for studying the characteristics of the Earth’s natural pulse electromagnetic field signal before a strong earthquake and we hope it can contribute to the electromagnetic anomaly monitoring before the earthquake. 展开更多
关键词 earths natural pulse electromagnetic field Chaos theory Radial Basis Function neural network Forecasting model
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Numerical Solution for a Similar Flow between Two Disks in the Presence of a Magnetic Field
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作者 Sajjad Hussain Muhammad Anwar Kamal +3 位作者 Farooq Ahmad Muhammad Ali Muhammad Shafique Sifat Hussain 《Applied Mathematics》 2013年第8期1163-1167,共5页
Numerical solutions are obtained for non-steady, incompressible fluid flow between two parallel disks which at time t are separated by a distance H(1-αt)1/2 and a magnetic field proportional to B0(1-αt) -1/2 is appl... Numerical solutions are obtained for non-steady, incompressible fluid flow between two parallel disks which at time t are separated by a distance H(1-αt)1/2 and a magnetic field proportional to B0(1-αt) -1/2 is applied perpendicular to the disks where H denotes a representative length, BO denotes a representative magnetic field and α-1 denotes a representative time. Similarity transformations are used to convert the governing partial differential equations of motion in to ordinary differential form. The resulting ordinary differential equations are solved numerically using SOR method, Richardson extrapolation and Simpson’s (1/3) Rule. Our numerical scheme is straightforward, efficient and easy to program. 展开更多
关键词 Numerical solution similar FLOW NEWTONIAN Fluid magnetic field Reynold’s Number
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Origin of Magnetic Fields of Stellar Objects in the Universe Based on the 5D Projection Theory
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作者 Peter C. W. Fung K. W. Wong 《Journal of Modern Physics》 2017年第4期668-746,共79页
Beginning with a 5D homogeneous universe [1], we have provided a plausible explanation of the self-rotation phenomenon of stellar objects previously with illustration of large number of star samples [2], via a 5D-4D p... Beginning with a 5D homogeneous universe [1], we have provided a plausible explanation of the self-rotation phenomenon of stellar objects previously with illustration of large number of star samples [2], via a 5D-4D projection. The origin of such rotation is the balance of the angular momenta of stars and that of positive and negative charged e-trino pairs, within a 3D &otimes;1D?void of the stellar object, the existence of which is based on conservation/parity laws in physics if one starts with homogeneous 5D universe. While the in-phase e-trino pairs are proposed to be responsible for the generation of angular momentum, the anti-phase but oppositely charge pairs necessarily produce currents. In the 5D to 4D projection, one space variable in the 5D manifold was compacted to zero in most other 5D theories (including theories of Kaluza-Klein and Einstein [3] [4]). We have demonstrated, using the Fermat’s Last Theorem [5], that for validity of gauge invariance at the 4D-5D boundary, the 4th space variable in the 5D manifold is mapped into two current rings at both magnetic poles as required by Perelman entropy mapping;these loops are the origin of the dipolar magnetic field. One conclusion we draw is that there is no gravitational singularity, and hence no black holes in the universe, a result strongly supported by the recent discovery of many stars with masses well greater than 100 solar mass [6] [7] [8], without trace of phenomena observed (such as strong gamma and X ray emissions), which are supposed to be associated with black holes. We analyze the properties of such loop currents on the 4D-5D boundary, where Maxwell equations are valid. We derive explicit expressions for the dipolar fields over the whole temperature range. We then compare our prediction with measured surface magnetic fields of many stars. Since there is coupling in distribution between the in-phase and anti-phase pairs of e-trinos, the generated mag-netic field is directly related to the angular momentum, leading to the result that the magnetic field can be expressible in terms of only the mechanical variables (mass M, radius R, rotation period P)of a star, as if Maxwell equations are “hidden”. An explanation for the occurrence of this “un-expected result” is provided in Section (7.6). Therefore we provide satisfactory answers to a number of “mysteries” of magnetism in astrophysics such as the “Magnetic Bode’s Relation/Law” [9] and the experimental finding that B-P graph in the log-log plot is linear. Moreover, we have developed a new method for studying the relations among the data (M, R, P) during stellar evolution. Ten groups of stellar objects, effectively over 2000 samples are used in various parts of the analysis. We also explain the emergence of huge magnetic field in very old stars like White Dwarfs in terms of formation of 2D Semion state on stellar surface and release of magnetic flux as magnetic storms upon changing the 2D state back to 3D structure. Moreover, we provide an explanation, on the ground of the 5D theory, for the detection of extremely weak fields in Venus and Mars and the asymmetric distribution of magnetic field on the Martian surface. We predict the equatorial fields B of the newly discovered Trappist-1 star and the 6 nearest planets. The log B?&minus;?log P graph for the 6 planets is linear and they satisfy the Magnetic Bode’s relation. Based on the above analysis, we have discovered several new laws of stellar magnetism, which are summarized in Section (7.6). 展开更多
关键词 5D Projection Theory Fermat’s Last Theorem Perelman’s Mappings self-Rotation Dipolar magnetic field of stars LAWs of sTELLAR magnetism LAWs of sTELLAR Angular Momentum magnetic Bode’s Law NON-EXIsTENCE of Gravitational singularity semion state of Atoms in sTELLAR surface magnetic storm Planetary magnetic field Maxwell Equations at 4D-5D Boundary magnetic fields of the Trappist-1 system
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Magnetic Structure of the Earth’s Crust in the White Sea Region
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作者 Lyubov Bakunovich Mikhail Nilov +1 位作者 Nikolay Sharov Boris Belashev 《International Journal of Geosciences》 2021年第11期1007-1020,共14页
The geological structure of the White Sea area and the surrounding land areas has been well studied in the framework of individual case studies. There are a number of local models of the deep structure of the Earth’s... The geological structure of the White Sea area and the surrounding land areas has been well studied in the framework of individual case studies. There are a number of local models of the deep structure of the Earth’s crust available. We propose a uniform assessment of deep crustal bodies responsible for long-period (regional) magnetic anomalies and consider their correlation with surface structures. The aim of the study is to build a three-dimensional magnetic model of the Earth’s crust in the White Sea region using aeromagnetic data and modeling technologies of the Integro software package. The model is formed on the basis of a digital map of the anomalous magnetic field reduced to the pole. The sources of magnetic anomalies are considered to be located in the Earth’s crust. The 3D distribution of the relative magnetic susceptibility of rocks was obtained by solving the inverse problem of <span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">magnetic survey. To separate the magnetic sources by frequency and depth, it was necessary to continue the magnetic field of the model upward and to calculate the TDR derivatives, which determine the lateral boundaries of the sources of positive magnetic field anomalies. 2D distributions of magnetic sources of the model for vertical and horizontal sections with depths of 10, 15 and 20 km are analyzed. The correlation between the surface and deep structures of magnetic sources of the Earth’s crust in the region is shown.</span> 展开更多
关键词 White sea earths Crust Anomalous magnetic field Effective magnetic sus-ceptibility 3D Model
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Constraining evolution of magnetic field strength in the dissipation region of two BL Lac objects
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作者 Xu-Liang Fan Da-Hai Yan +1 位作者 Qing-Wen Wu Xu Chen 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第12期351-356,共6页
With the assumption that the optical variability timescale is dominated by the cooling time of the synchrotron process for BL Lac objects,we estimate time dependent magnetic field strength of the emission region for t... With the assumption that the optical variability timescale is dominated by the cooling time of the synchrotron process for BL Lac objects,we estimate time dependent magnetic field strength of the emission region for two BL Lac objects.The average magnetic field strengths are consistent with those estimated from core shift measurement and spectral energy distribution modelling.Variation of magnetic field strength in the dissipation region is discovered.Variability of flux and magnetic field strength shows no clear correlation,which indicates the variation of magnetic field is not the dominant reason of the variability origin.The evolution of magnetic field strength can provide another approach to constrain the energy dissipation mechanism in jets. 展开更多
关键词 BL Lacertae objects:general BL Lacertae objects:individual(s50716%PLUs%714 BL Lacertae) galaxies:magnetic fields
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