The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Dongming Tang - One of the best experts on this subject based on the ideXlab platform.
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coxfey c composites with tunable atomic ratios for excellent electroMagnetic absorption properties
Scientific Reports, 2015Co-Authors: Hualiang Lv, Guangbin Ji, Haiqian Zhang, Meng Li, Yue Zhao, Baoshan Zhang, Dongming Tang, Youwei DuAbstract:The shell on the nano-Magnetic absorber can prevent oxidation, which is very important for its practical utilization. Generally, the nonMagnetic shell will decrease the integral Magnetic Loss and thus weaken the electroMagnetic absorption. However, maintaining the original absorption properties of the Magnetic core is a major challenge. Here, we designed novel and facile CoxFey@C composites by reducing CoxFe3−xO4@phenolic resin (x = 1, 0.5 and 0.25). High saturation magnetization value (Ms) of CoxFey particle, as a core, shows the interesting Magnetic Loss ability. Meanwhile, the carbon shell may increase the integral dielectric Loss. The resulting composite shows excellent electroMagnetic absorption properties. For example, at a coating thickness of 2 mm, the RLmin value can reach to −23 dB with an effective frequency range of 7 GHz (11–18 GHz). The mechanisms of the improved microwave absorption properties are discussed.
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CoxFey@C Composites with Tunable Atomic Ratios for Excellent ElectroMagnetic Absorption Properties
Scientific reports, 2015Co-Authors: Haiqian Zhang, Yue Zhao, Baoshan Zhang, Zhongzheng Zuo, Dongming TangAbstract:The shell on the nano-Magnetic absorber can prevent oxidation, which is very important for its practical utilization. Generally, the nonMagnetic shell will decrease the integral Magnetic Loss and thus weaken the electroMagnetic absorption. However, maintaining the original absorption properties of the Magnetic core is a major challenge. Here, we designed novel and facile CoxFey@C composites by reducing CoxFe3−xO4@phenolic resin (x = 1, 0.5 and 0.25). High saturation magnetization value (Ms) of CoxFey particle, as a core, shows the interesting Magnetic Loss ability. Meanwhile, the carbon shell may increase the integral dielectric Loss. The resulting composite shows excellent electroMagnetic absorption properties. For example, at a coating thickness of 2 mm, the RLmin value can reach to −23 dB with an effective frequency range of 7 GHz (11–18 GHz). The mechanisms of the improved microwave absorption properties are discussed.
Jinyeong Moon - One of the best experts on this subject based on the ideXlab platform.
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Direct in-situ Measurement of Magnetic Loss in Power Electronic Circuits
IEEE Transactions on Power Electronics, 2021Co-Authors: Jinyeong MoonAbstract:Timing skew between measurement channels can introduce an unacceptable error in power Loss measurement and is difficult to quantify, rendering precise in-situ measurement of Magnetic Loss essentially unattainable. This article rams the issue head-on by presenting the mathematical model for the timing skew and developing two methods based on the model to realize in-situ direct Magnetic Loss measurement. The mathematical model is first established to analyze the effects of timing skew on the measured Magnetic Loss in a dc–dc converter. The first method, called intersection method, illustrates how to unravel the entangled relationship between the actual timing skew and real Magnetic Loss in the circuit with the aid of the mathematical model. The second method, called derivative method, builds on the intersection method and greatly enhances the accuracy and the repeatability of the Loss measurement. Our novel approach for in-situ Magnetic Loss measurement is verified in simulation and experiment with a conventional dc–dc step-down buck converter under various operating conditions and design parameters.
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Novel Methods for In-situ Direct Magnetic Loss Measurement in a DC-DC Converter
2020 IEEE Applied Power Electronics Conference and Exposition (APEC), 2020Co-Authors: Jinyeong MoonAbstract:Timing skew between measurement channels can introduce an unacceptable error in power Loss measurement, making in-situ Magnetic Loss measurement one of the most difficult engineering problems. This paper develops a mathematical model and provides two novel methods to realize insitu direct Magnetic Loss measurement. The mathematical model is first established to study the effects of timing skew on the measured/observed Magnetic Loss in a DC-DC converter. The first method, called Intersection method, is proposed and analyzed in detail. This method will illustrate how the actual timing skew and actual Magnetic Loss in circuit can be obtained with the aid of the mathematical model. The second method, called Derivative method, will be shown that it greatly enhances the accuracy and repeatability of the same measurements. The proposed methods are verified in simulation and experimentally validated in a conventional step-down DC-DC buck converter under various operating conditions and design parameters.
Tong Xue - One of the best experts on this subject based on the ideXlab platform.
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nanocasting synthesis of fe3o4 htc nanocapsules and their superior electroMagnetic properties
RSC Advances, 2016Co-Authors: Zhihong Yang, Tong XueAbstract:Magnetic nanocapsules with Fe3O4 nanorods as the core and hydrothermal carbon (HTC) as the shell have been synthesized using a nanocasting method. Due to the strong shape anisotropy of the nanorods, the nanocapsules exhibit a higher coercivity and increased resonance at the high frequency range. Benefiting from the improvement of dielectric Loss and Magnetic Loss at high frequency, the Fe3O4@HTC nanocapsule composites show superior microwave attenuation properties.
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Nanocasting synthesis of Fe3O4@HTC nanocapsules and their superior electroMagnetic properties
RSC Advances, 2016Co-Authors: Zhihong Yang, Tong XueAbstract:Magnetic nanocapsules with Fe3O4 nanorods as the core and hydrothermal carbon (HTC) as the shell have been synthesized using a nanocasting method. Due to the strong shape anisotropy of the nanorods, the nanocapsules exhibit a higher coercivity and increased resonance at the high frequency range. Benefiting from the improvement of dielectric Loss and Magnetic Loss at high frequency, the Fe3O4@HTC nanocapsule composites show superior microwave attenuation properties.
Haiqian Zhang - One of the best experts on this subject based on the ideXlab platform.
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coxfey c composites with tunable atomic ratios for excellent electroMagnetic absorption properties
Scientific Reports, 2015Co-Authors: Hualiang Lv, Guangbin Ji, Haiqian Zhang, Meng Li, Yue Zhao, Baoshan Zhang, Dongming Tang, Youwei DuAbstract:The shell on the nano-Magnetic absorber can prevent oxidation, which is very important for its practical utilization. Generally, the nonMagnetic shell will decrease the integral Magnetic Loss and thus weaken the electroMagnetic absorption. However, maintaining the original absorption properties of the Magnetic core is a major challenge. Here, we designed novel and facile CoxFey@C composites by reducing CoxFe3−xO4@phenolic resin (x = 1, 0.5 and 0.25). High saturation magnetization value (Ms) of CoxFey particle, as a core, shows the interesting Magnetic Loss ability. Meanwhile, the carbon shell may increase the integral dielectric Loss. The resulting composite shows excellent electroMagnetic absorption properties. For example, at a coating thickness of 2 mm, the RLmin value can reach to −23 dB with an effective frequency range of 7 GHz (11–18 GHz). The mechanisms of the improved microwave absorption properties are discussed.
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CoxFey@C Composites with Tunable Atomic Ratios for Excellent ElectroMagnetic Absorption Properties
Scientific reports, 2015Co-Authors: Haiqian Zhang, Yue Zhao, Baoshan Zhang, Zhongzheng Zuo, Dongming TangAbstract:The shell on the nano-Magnetic absorber can prevent oxidation, which is very important for its practical utilization. Generally, the nonMagnetic shell will decrease the integral Magnetic Loss and thus weaken the electroMagnetic absorption. However, maintaining the original absorption properties of the Magnetic core is a major challenge. Here, we designed novel and facile CoxFey@C composites by reducing CoxFe3−xO4@phenolic resin (x = 1, 0.5 and 0.25). High saturation magnetization value (Ms) of CoxFey particle, as a core, shows the interesting Magnetic Loss ability. Meanwhile, the carbon shell may increase the integral dielectric Loss. The resulting composite shows excellent electroMagnetic absorption properties. For example, at a coating thickness of 2 mm, the RLmin value can reach to −23 dB with an effective frequency range of 7 GHz (11–18 GHz). The mechanisms of the improved microwave absorption properties are discussed.
Jianbo Wang - One of the best experts on this subject based on the ideXlab platform.
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microwave permeability spectra of flake shaped fecunbsib particle composites
Journal of Applied Physics, 2008Co-Authors: Liang Qiao, Fusheng Wen, Jianqiang Wei, Jianbo WangAbstract:The effective permeability of flake-shaped FeCuNbSiB particles/nonMagnetic matrix composition in high frequency was measured and calculated. In contrast to the relatively larger size and irregular shape particles, the flake particles have higher permeability. The results are attributed to the different Magnetic Loss mechanisms. According to the skin-effect criterion, we find that the Magnetic Loss in flake particles is mainly caused by the natural resonance, compared with the eddy current effect in the larger size and irregular shape particles. Using the shape anisotropy, the flake soft Magnetic particles overcome the difficulty of the relatively small intrinsic anisotropies and increase the natural resonant frequencies to the gigahertz range, leading to the higher real part and imaginary part of the permeability. The resonance peak of flake particles was simulated using the combination of the Landau–Lifshitz–Gilbert equation and Bruggeman’s effective medium theory considering a random spatial distributio...