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本文基于频率跨度较大的单极性长持续时间雷电流波,就如何拓宽自积分式Rogowski线圈测量带宽及如何增大电流测量范围的问题展开研究。针对脉冲电流波具有波前部分快速变化与波尾部分缓慢变化的特点,在对不同脉冲电流波频谱分析的基础上,设计了锰锌(Mn-Zn)和镍锌(Ni-Zn)铁氧体作为磁芯的自积分式Rogowski线圈,对不同频率跨度的脉冲电流波进行测量。对比测量结果,得到以下结论:镍锌铁氧体作为磁芯,磁导率越高,线圈下限频率越低,低频响应越好,而高频部分的响应越差;磁导率相同的锰锌铁氧体和镍锌铁氧体磁芯,饱和磁通越大,线圈所能准确测量的电流幅值越大。 相似文献
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AbstractAsphalt-based composites have the ability to heal themselves.without the aid of external influences (energy supply or material supplement), the self-healing ability of asphalt mixture is quite limited. In this paper, the efficiency of self-healing of asphalt mixture with Ni-Zn ferrite powders was analyzed based on the concept of microwave heating. We focused on assessing the characteristics of polyurethane (PU), base or styrene-butadiene-styrene (SBS) modified asphalt and its mixtures. The recovery rate of stiffness modulus and the fatigue life extension ratio were adopted to evaluate the self-healing efficiency of asphalt mixture. The analysis results proved that Ni-Zn ferrite powders can promote the self-healing ability of asphalt mixture significantly, the fatigue life extension ratio of 50% damaged ferrite-filled asphalt mixture can reach 1.33. 相似文献
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软磁铁氧体纳米超微粉及其热动力学性质的研究进展 总被引:5,自引:0,他引:5
综述耻近年来软磁铁氧体纳米粉的制备方法及热动力学性质的研究进展。软磁铁氧体纳米的制备主要采用共沉淀法。溶胶-凝胶法,水热法,微乳液法等湿化学方法。软磁铁氧体中阳离子的热稳定性,组成与空位及阳离子分布的关系,电性能等是目前人们对软磁铁氧体热动力学研究中所感兴趣的几个方面。 相似文献
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主要介绍了上海宝钢磁业发展有限公司批量生产的高频、高居里温度、超高磁导率锰锌软磁铁氧体材料BRL15K的工艺技术及材料特性。 相似文献
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基于M型锶六角铁氧体的高各向异性场,采用HFSS软件设计了中心频率在28.2GHz的自偏置边导模隔离器。仿真结果表明,在28.2GHz附近,插入损耗为6dB,隔离度大于38dB,20dB以下隔离带宽约为3.5GHz。采用传统固相反应法制备SrM六角铁氧体材料基片并用丝网印刷工艺实现基片上的微带电路,根据设计的结构参数制备了自偏置边导模隔离器。测试结果表明,该自偏置隔离器在27~29GHz范围内,表现出强烈的非互易性,插入损耗小于10dB,最大隔离度大于45dB。由于不需要外加偏置磁场,器件实现了小型化,宽频带,仿真与实测吻合得较好。 相似文献
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A novel three-phase, double-percolating composite with a ferromagnetic phase (NiZn ferrite) and metallic inclusion (nickel) embedded in the polyvinylidene fluoride matrix is prepared by a simple hot-molding method. The large ferrite particles in the composite not only act as magnetic phase, endowing the composite with high initial permeability, but also present as a high-volume fraction discrete (nonpercolating) phase, confining polymer and metallic particles into a continuous double-percolating structure of low volume fractions. The increase in the content of the magnetic nickel particles compensates the decrease in the content of the NiZn ferrite, hence a stable initial permeability with an enhanced dielectric constant has been observed. The dielectric losses of the composites were reduced compared with the previous works. 相似文献
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Rekha Rani Sangeeta Singh J. K. Juneja K. K. Raina Chandra Prakash 《Journal of Electroceramics》2014,32(2-3):141-145
For the present study, two phase ceramic (ferroelectric-ferrite) composites using La substituted lead zirconate titanate (PLZT) and Ni-Zn ferrite (NZF) with compositional formula x Ni0.8Zn0.2Fe2O4-(1-x) Pb0.99La0.02Zr0.65Ti0.35O3 (x?=?0, 0.05, 0.10 and 0.15) were synthesized by conventional solid state reaction route. From X-ray analysis, it was confirmed that no chemical reaction took place between individual phases. Dielectric properties were studied as a function of temperature and frequency. Decrease in dielectric constant and increase in dielectric loss was observed with increasing ferrite content. Anomalous behavior in paraelectric region was observed for all the composite samples (x?=?0.05, 0.10 and 0.15) at low frequencies. To study ferroelectric and ferromagnetic properties, P-E and M-H hysteresis loops were recorded respectively. Effect of electric field on magnetization was studied for all composite samples to confirm magnetoelectric coupling. 相似文献
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针对微波铁氧体移相器的工作原理和磁路特点,对作为磁轭的软磁铁氧体材料的基本参数与尺寸、温度稳定性、磁导率及其频谱特性、激活能、应力敏感性等的要求进行了分析. 相似文献
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Multifunctional dielectric composites with electromagnetic and flexible properties for RF applications were investigated. A kind of low loss flexible dielectric and magnetic composite with SrTiO3 (STO) ultrafine particles and NiZn ferrite (NZO) ultrafine particles embedded in a Thermoplastic Polyolefin Elastomer (POE) matrix was fabricated using the extrusion technology. The dielectric and magnetic properties of the as-prepared composites with different volume fraction of ceramic fillers were studied. The results indicate that when the volume of the ceramic fillers is fixed, the permittivity of the composites increase while the dielectric loss, permeability and magnetic loss decrease with the increasing of the ratio of STO to NZO. The cut-off frequencies of the composites are all above 1 GHz. The good frequency stability of the electromagnetic properties within a wide frequency range was observed. All the composites show very good flexibilities. With the increasing of the volume fraction of ceramic fillers, the tensile strength and elongation decrease. The obtained multifunctional flexible magnetic-dielectric composites are good candidates for the applications of the capacitor-inductor integrating devices in RF communications such as electromagnetic interference filters and antennas. 相似文献