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High-frequency magnetic properties and core loss of carbonyl iron composites with easy plane-like structures 被引量:1
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作者 Guo-Wu Wang Chun-Sheng Guo +2 位作者 Liang Qiao Tao Wang Fa-Shen Li 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期508-513,共6页
To fully release the potential of wide bandgap(WBG)semiconductors and achieve high energy density and efficiency,a carbonyl iron soft magnetic composite(SMC)with an easy plane-like structure is prepared.Due to this st... To fully release the potential of wide bandgap(WBG)semiconductors and achieve high energy density and efficiency,a carbonyl iron soft magnetic composite(SMC)with an easy plane-like structure is prepared.Due to this structure,the permeability of the composite increases by 3 times(from 7.5 to 21.5)at 100 MHz compared with to the spherical carbonyl iron SMC,and the permeability changes little at frequencies below 100 MHz.In addition,the natural resonance frequency of the composite shifts to higher frequencies at 1.7 GHz.The total core losses of the composites at 10,20,and 30 m T are80.0,355.3,and 810.7 m W/cm^(3),respectively,at 500 k Hz.Compared with the spherical carbonyl iron SMC,the core loss at500 k Hz is reduced by more than 60%.Therefore,this kind of soft magnetic composite with an easy plane-like structure is a good candidate for unlocking the potential of WBG semiconductors and developing the next-generation power electronics. 展开更多
关键词 soft magnetic composite high frequency magnetic property power electronic core loss
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Low frequency acoustic properties of bilayer membrane acoustic metamaterial with magnetic oscillator 被引量:4
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作者 Nansha Gao Hong Hou Yihao Mu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第4期252-257,共6页
A bilayer membrane acoustic metamaterial was proposed to overcome the influence of the mass law on traditional acoustic materials and obtain a lightweight thin-layer structure that can effectively isolate low frequenc... A bilayer membrane acoustic metamaterial was proposed to overcome the influence of the mass law on traditional acoustic materials and obtain a lightweight thin-layer structure that can effectively isolate low frequency noise. The finite element analysis(FEA) results agree well with the experimental results.It is proved that the sound transmission losses(STLs) of the proposed structures are higher than those of same surface density acoustic materials. The introduction of the magnetic mass block is different from the traditional design method, in which only a passive mass block is fixed on the membrane. The magnetic force will cause tension in the membrane, increase membrane prestress, and improve overall structural stiffness. The effects of the geometry size on the STLs are discussed in detail. The kind of method presented in this paper can provide a new means for engineering noise control. 展开更多
关键词 Bilayer membrane acoustic metamaterial Low frequency sound insulation Sound transmission loss Magnet oscillator
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EXTREMELY LOW FREQUENCY MAGNETIC FIELD SUSCEPTIBILITY OF VISUAL DISPLAY UNITS
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作者 傅正财 杜亚平 J.Burnett 《Journal of Shanghai Jiaotong university(Science)》 EI 2001年第2期201-205,共5页
Extremely low frequency (ELF) magnetic field susceptibility is an index of visual display unit (VDU) quality and performance. This paper provided field measured data on the susceptibility for a large variety of VDUs. ... Extremely low frequency (ELF) magnetic field susceptibility is an index of visual display unit (VDU) quality and performance. This paper provided field measured data on the susceptibility for a large variety of VDUs. A test rig was built to study the susceptibility of VDUs to magnetic fields at fundamental and third harmonic frequencies. It was found that the susceptibility level is largely dependent on refresh rate of the VDU and the orientation of the external ELF field. It was also found that the VDU susceptibility is significantly increased in the presence of harmonic frequency magnetic fields. About 30% of the tested samples have susceptibility levels higher than that stated in IEC 1000-4-8 standard. 展开更多
关键词 visual display unit extremely low frequency magnetic field electromagnetic compatibility susceptibility test
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Relations among High-frequency Magnetic Properties and Frequency in Nanocrystalline Fe_(72.5)Cu_1Nb_2V_2Si_(13.5)B_9 Alloy
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作者 Yanzhong ZHANG(Major R & D Lab. for Functional Metal Materials, Research Centre, Shanghai Iron and Steel Research Institute,Shanghai 200940, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1999年第1期83-86,共4页
High-frequency magnetic properties, such as core loss, coercivity and amplitude permeabilityof a newly-developed nanocrystalline Fe72.5Cu1Nb2V2Si13.5B9 alloy in the wide ranges of f =20-103 kHz, Bm = 0.01~0.6 T and Bm... High-frequency magnetic properties, such as core loss, coercivity and amplitude permeabilityof a newly-developed nanocrystalline Fe72.5Cu1Nb2V2Si13.5B9 alloy in the wide ranges of f =20-103 kHz, Bm = 0.01~0.6 T and Bmf = 10~40 (T.kHz) have been measured. A largeamount of experimental data have been fitted by a computer, thus obtaining several expressionsrepresenting the influence of frequency on high-frequency magnetic properties, that are useful inpractical applications. 展开更多
关键词 Cu1Nb2V2Si B9 Alloy Relations among High-frequency magnetic Properties and frequency in Nanocrystalline Fe kHz FE Si
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Magnetic field enhanced radio frequency ion source and its application for Si-incorporation diamond-like carbon film preparation
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作者 Jiping YIN Qing WANG +3 位作者 Xinlong WU Chunyu CHENG Dechun BA Zeng LIN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第2期79-86,共8页
Various ion sources are key components to prepare functional coatings,such as diamond-like carbon(DLC)films.In this article,we present our trying of surface modification on basis of Si-incorporation diamond-like carbo... Various ion sources are key components to prepare functional coatings,such as diamond-like carbon(DLC)films.In this article,we present our trying of surface modification on basis of Si-incorporation diamond-like carbon(Si-DLC)produced by a magnetic field enhanced radio frequency ion source,which is established to get high density plasma with the help of magnetic field.Under proper deposition process,a contact angle of 111°hydrophobic surface was achieved without any surface patterning,where nanostructure SiC grains appeared within the amorphous microstructure.The surface property was influenced by ion flow parameters as well as the resultant surface microstructure.The magnetic field enhanced radio frequency ion source developed in this paper was useful for protective film applications. 展开更多
关键词 magnetic field enhanced radio frequency ion source Si-incorporation diamond-like carbon film MICROSTRUCTURE HYDROPHOBICITY protective film
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Meniscus Behavior in Electromagnetic Soft-Contact Continuous Casting Round Billet Mold 被引量:19
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作者 DENG An-yuan WANG En-gang HE Ji-cheng 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第4期13-16,共4页
Using molten Pb-Sn-Bi alloy, the meniscus shape under high frequency magnetic field of φ100 mm round billet caster was investigated. The effect of some parameters on meniscus shape was studied. The results show that ... Using molten Pb-Sn-Bi alloy, the meniscus shape under high frequency magnetic field of φ100 mm round billet caster was investigated. The effect of some parameters on meniscus shape was studied. The results show that for a mold with 12 segments, the meniscus shape is relatively stable. With increasing power input, the menis- cus height increases with intensification of fluctuation. For the given caster, the reasonable power input is about 70 kW. The coil should be near to the top of mold and/or the initial meniscus should be near to the center of the coil. The lower the frequency, the higher is the meniscus height. With increasing frequency, the free surface is more flattened and meniscus becomes more stable. In practice, the power input should be increased simultaneously with frequency. The optimal frequency is about 20 kHz. 展开更多
关键词 continuous casting soft-contact mold meniscus behavior high frequency magnetic field
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Combined Effects of 50 Hz Magnetic Field and Magnetic Nanoparticles on the Proliferation and Apoptosis of PC12 Cells 被引量:2
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作者 JIA Hong Li WANG Chao +4 位作者 LI Yue LU Yan WANG Ping Ping PAN Wei Dong SONG Tao 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第2期97-105,共9页
Objective To investigate the bioeffects of extremely low frequency (ELF) magnetic field (MF) (50 Hz, 400 μT) and magnetic nanoparticles (MNPs) via cytotoxicity and apoptosis assays on PC12 cells. Methods MNPs... Objective To investigate the bioeffects of extremely low frequency (ELF) magnetic field (MF) (50 Hz, 400 μT) and magnetic nanoparticles (MNPs) via cytotoxicity and apoptosis assays on PC12 cells. Methods MNPs modified by SiO2 (MNP-SiO2) were characterized by transmission electron microscopy (TEM), dynamic light scattering and hysteresis loop measurement. PC12 cells were administrated with MNP-SiO2 with or without MF exposure for 48 h. Cytotoxicity and apoptosis were evaluated with MTI- assay and annexin V-FITC/PI staining, respectively. The morphology and uptake of MNP-SiO2 were determined by TEM. MF simulation was performed by Ansoft Maxwell based on the finite element method. Results MNP-SiO2 were identified as -20 nm (diameter) ferromagnetic particles. MNP-SiO2 reduced cell viability in a dose-dependent manner. MF also reduced cell viability with increasing concentrations of MNP-SiO2. MNP-SiO2 alone did not cause apoptosis in PC12 cells; instead, the proportion of apoptotic cells increased significantly under MF exposure and increasing doses of MNP-SiO2. MNP-SiO2 could be ingested and then cause a slight change in cell morphology. Conclusion Combined exposure of MF and MNP-SiO2 resulted in remarkable cytotoxicity and increased apoptosis in PC12 cells. The results suggested that MF exposure could strengthen the MF of MNPs, which may enhance the bioeffects of ELF MF. 展开更多
关键词 Extremely low frequency magnetic field magnetic nanoparticles CYTOTOXICITY APOPTOSIS MORPHOLOGY
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Numerical simulation of applied electromagnetic field and electromagnetic force in all-position welding 被引量:1
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作者 牛雪娟 李亮玉 +1 位作者 姜旭东 岳建锋 《China Welding》 EI CAS 2013年第3期42-45,共4页
All-position welding is an important technology in energy sources, chemical, shipbuilding and other industries. When welding current is larger than 200 A, the molten metal tends to flow down due to the force of gravit... All-position welding is an important technology in energy sources, chemical, shipbuilding and other industries. When welding current is larger than 200 A, the molten metal tends to flow down due to the force of gravity. In order to "push" the molten metal into the weld, a new kind of U-frame excitation model, which could produce electromagnetic force to balance the gravity of the molten pool, was designed. The related parameters of the excitation model were simulated by Maxwell 3D, and the relationships between the parameters and the magnetic induction intensity were analyzed. Finally, the electromagnetic force in the molten pool was calculated, and the appropriate parameters of the U-frame excitation model were determined. The results of the simulation verify the feasibility of the all-position welding excitation model. 展开更多
关键词 all-position welding electromagnetic force high frequency alternating magnetic field
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Homeopathy--A Regulation Therapy Healing Hypo- or Hyper-functions of Pathological Pathways by Magnetic Photons according to the Resonance Principle
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作者 Lenger Karin 《Journal of Life Sciences》 2017年第2期53-64,共12页
Since Lenger's detection of magnetic photons in homeopathic remedies by magnetic resonance the mystery of homeopathy comes to a solution. Homeopathy is a regulation therapy curing hypo- and hyper-functions of patholo... Since Lenger's detection of magnetic photons in homeopathic remedies by magnetic resonance the mystery of homeopathy comes to a solution. Homeopathy is a regulation therapy curing hypo- and hyper-functions of pathological pathways. It reacts according to the principle of resonance. The fundamental principles of homeopathy as proving, symptom picture, curing according to the Law of Similars and the production of homeopathic remedies over the Avogadro number by repeated dilution and succussion are explained to have the same frequencies so that the resonance principle can work. Pathological pathways are cured by using their highly potentized substrates, inhibitors and enzymes, given daily or each second day. This is in contradiction to the normal applied homeopathy. The efficacy of homeopathy now has a scientific base and is completely explained by applying biochemical and biophysical laws. 展开更多
关键词 magnetic photons resonance principle magnetic frequencies homeopathic remedies homeopathic healing.
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Electromagnetic Environmental Impact of 500-kV Double -Circuit Transmission Lines
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作者 Qi Jianzhao, Zhang Guohua, Wu Xiaoyan Hebei Electric Power Design & Research Institute Zhang Jianping 《Electricity》 2011年第1期24-28,共5页
The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environm... The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environmental impact factors of the fields were evaluated. By optimizing the phase sequence, the frequency electric intensity and magnetic field strength can be reduced. Within a distance of 25 m from the center of the transmission line, the power frequency electric intensity and magnetic field strength fall off sharply with the distance increase. Finally, the best phase sequence and the minimum ground clearance of the transmission lines were obtained to meet the requirements of the least impact on envionment. 展开更多
关键词 transmission line frequency electric field intensity frequency magnetic field strength
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Effects of extremely low frequency magnetic field on anxiety level and spatial memory of adult rats 被引量:2
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作者 HE Li-hua SHI Hong-mei +3 位作者 LIUTong-tong XU Ying-chun YE Kang-ping WANG Sheng 《Chinese Medical Journal》 SCIE CAS CSCD 2011年第20期3362-3366,共5页
Background As the widespread use of electric devices in modern life, human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever. Over the past decades, a substantial number ... Background As the widespread use of electric devices in modern life, human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever. Over the past decades, a substantial number of epidemiological and experimental studies have demonstrated that ELF MF (50 Hz) exposure is associated with increased risk of various health effects. The present study examined the effects of chronic exposure to ELF MF on anxiety level and spatial memory of adult rats. Methods The 50-Hz ELF MF was used during the whole experimental procedures and the value of magnetic field (MF) was set to 2 mT. Adult rats were divided randomly to control, MF 1 hour and MF 4 hours group. Anxiety-related behaviors were examined in the open field test and the elevated plus maze; changes in spatial learning and memory were determined in Morris water maze aRer 4 weeks of daily exposure. Results Rats in MF 4 hours group had increased anxiety-like behaviors with unaltered locomotor activity. In the Morris water maze test, rats had reduced latency to find the hidden platform and improved long-term memory of former location of platform without changes in short-term memory and locomotor activity. Conclusion Chronic ELF MF exposure has anxiogenic effect on rats, and the promoting effects on spatial learning and long-term retention of spatial memory. 展开更多
关键词 extremely low frequency magnetic field ANXIETY spatial memory Morris water maze test open field test
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Parametric Instability of a Liquid Metal Sessile Drop Under a High Frequency Amplitude-Modulate Magnetic Field
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作者 LEI Zuo-sheng ZHANG Li-jie +4 位作者 CHEN Chao-yue GUO Jia-hong REN Zhong-ming FAUTRELLE Yves ETAY Jecqueline 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2012年第S1期491-494,共4页
The parametric instability behavior of a liquid mercury sessile drop under high frequency Amplitude-Modulate Magnetic Field(AMMF),i.e.a high frequency magnetic field(carder wave)modulated by a low frequency sine wave(... The parametric instability behavior of a liquid mercury sessile drop under high frequency Amplitude-Modulate Magnetic Field(AMMF),i.e.a high frequency magnetic field(carder wave)modulated by a low frequency sine wave(modulate wave),is investigated experimentally.The free surface contour of the mercury drop is observed by a CCD camera while varying the frequency and amplitude of the high frequency AMMF.At a given frequency and amplitude,the edge deformations with an azimuthal wave numbers(modes n=3,4,5,6)were excited. 展开更多
关键词 high frequency Amplitude-Modulate magnetic Field liquid metal sessile drop parametric instability
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Novel and Simple Calorimetric Methods for Quantifying Losses in Magnetic Core and GaN Transistor in a High Frequency Boost Converter
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作者 Wenbo Wang Frans Pansier +1 位作者 Sjoerd de Haan J.A.Ferreira 《Chinese Journal of Electrical Engineering》 2016年第2期68-75,共8页
In design and implementation of a boost converter,information on loss characteristics of switching devices and magnetic materials is a prerequisite,especially in high frequency applications.To gather such information,... In design and implementation of a boost converter,information on loss characteristics of switching devices and magnetic materials is a prerequisite,especially in high frequency applications.To gather such information,testing and accurate loss quantification is needed.Previous methods for measuring magnetic core loss are either only suitable for sinusoidal wave excitations or cannot separate winding loss from inductor loss.In addition,existing loss measurement approaches on the newly introduced GaN transistors are not satisfactory.In this paper,we present a new method to distinguish winding loss from inductor loss under practical excitations.This method utilizes a converter to generate the actual excitation waveforms and uses a calorimetric setup to quantify the losses.By splitting up the inductor in a converter into an air-core inductor and a magnetic-core inductor,both equipped with exactly the same winding structure,the air-core inductor loss can be used as the reference of the magnetic-core inductor winding loss.In this way,losses in the magnetic core can be determined in the actual operating condition of a converter in which the inductor is to be used.Moreover,a simple calorimetric approach for obtaining loss information of GaN transistors are is also presented.Both methods require simple setup and are easy and convenient to execute.The methods work well in assessing different high frequency magnetic core materials and measuring losses in GaN transistors at 1MHz. 展开更多
关键词 Core loss measurement practical excitation high frequency magnetic material practical excitation transistor loss measurement calorimetric method
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Load shedding scheme for an interconnected hydro-thermal hybrid system with SMES 被引量:1
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作者 D. TYAGI Ashwani KUMAR Saurabh CHANANA 《Frontiers in Energy》 SCIE CSCD 2012年第3期227-236,共10页
The frequency of based on the load pattern the power system varies of the consumers. With continuous increase in the load, the frequency of the system keeps decreasing and may reach its minimum allowable limits. Furth... The frequency of based on the load pattern the power system varies of the consumers. With continuous increase in the load, the frequency of the system keeps decreasing and may reach its minimum allowable limits. Further increase in the load will result in more frequency drop leading to the need of load shedding, if excess generation is not available to cater the need. This paper proposed a methodology in a hybrid thermal-hydro system for finding the required amount of load to be shed for setting the frequency of the system within its minimum allowable limits. The load shedding steps were obtained based on the rate of change of frequency with the increase in the load in both areas. The impact of superconducting magnetic energy storage (SMES) was obtained on load shedding scheme. The comparison of the results was presented on the two-area system. 展开更多
关键词 critical load frequency response load shedding multi-area system rate of change of frequency superconducting magnetic energy storage (SMES) device
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