scholarly journals Facile synthesis and microwave absorption investigation of activated carbon@Fe3O4 composites in the low frequency band

RSC Advances ◽  
2018 ◽  
Vol 8 (41) ◽  
pp. 23048-23057 ◽  
Author(s):  
Pengfei Yin ◽  
Yu Deng ◽  
Limin Zhang ◽  
Ning Li ◽  
Xing Feng ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electromagnetic Wave ◽  
Hydrothermal Method ◽  
Microwave Absorption ◽  
Frequency Band ◽  
Low Frequency ◽  
Frequency Range ◽  
Facile Synthesis

Activated carbon@Fe3O4 composites with good electromagnetic wave absorbing performances in the low frequency range were synthesized via a hydrothermal method.

scholarly journals Enhanced Magnetic Microwave Absorption at Low‐Frequency Band by Ferrite Assembled Microspheres with Controlled Components and Morphologies

2021 ◽  
Author(s):  
Mengqiu Huang ◽  
Xuefeng Yu ◽  
Lei Wang ◽  
Jiwei Liu ◽  
Wenbin You ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Frequency Band ◽  
Low Frequency

Facile synthesis and enhanced microwave absorption properties of anthracite-based carbon/Ni3Fe/NiO ternary composites

2020 ◽  
Vol 44 (33) ◽  
pp. 13962-13970
Author(s):  
Hengdong Ren ◽  
Jialin Ma ◽  
Jun Zhou ◽  
Xiangfeng Shu ◽  
Zhenying Liu ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Microwave Radiation ◽  
Low Frequency ◽  
Microwave Absorber ◽  
Facile Synthesis ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Radiation Method ◽  
Microwave Radiation Method

A low-frequency microwave absorber was synthesized by using a microwave radiation method.

scholarly journals Reduced graphene oxide decorated with octahedral NiS2/NiS nanocrystals: facile synthesis and tunable high frequency attenuation

RSC Advances ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 5550-5556 ◽  
Author(s):  
Min Lu ◽  
Na Gao ◽  
Xiao-Juan Zhang ◽  
Guang-Sheng Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Microwave Absorption ◽  
High Frequency ◽  
High Frequency Range ◽  
Frequency Range ◽  
Facile Synthesis ◽  
Reduced Graphene ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Reduced graphene oxide (RGO) decorated with octahedral NiS2/NiS nanocrystals were fabricated and they possessed an excellent microwave absorption performance in the high frequency range.

scholarly journals Flicker-noise. Features, diversity and management

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
A.S. Matsaev
Keyword(s):  
Frequency Band ◽  
Flicker Noise ◽  
Low Frequency ◽  
Frequency Range ◽  
High Frequencies ◽  
Radio Electronics ◽  
Fractional Noises

The article refers to the field of research of noise fluctuations or flicker-noises in electronic amplifiers. The variety of flicker-noise in the energy and frequency dimension is shown, that the manifestation of flicker-noise is not limited to ultra-low frequency range, but under certain conditions can extend to medium and high frequencies. Some areas of radio electronics exposed or using flicker-noise properties are illuminated. It is shown that flicker-noises have a limit level of build-up in accordance with the energy and frequency band forming its thermal and fractional noises. It is shown that for electronic amplifiers flicker-noise is impractical to approximate the simplified ratio of 1/f. Methods of elimination or leveling of flicker-noise are given.

Dynamic analysis and vibration reduction of articulated silicone gel column with varying geometry

2021 ◽  
pp. 1-13
Author(s):  
Ji-Hou Yang ◽  
Xiao-Dong Yang ◽  
Qing-Kai Han ◽  
Jinguo Liu
Keyword(s):  
Frequency Band ◽  
Vibration Reduction ◽  
Low Frequency ◽  
Vibration Absorber ◽  
Frequency Range ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Silicone Gel ◽  
Resonance Frequencies ◽  
Reduction Effect

Abstract To improve vibration reduction effect in low-frequency band of dynamic vibration absorber (DVA), a novel type of articulated silicone gel column (SGC) is introduced in the design of the tuned dynamic vibration absorber. The nonlinear variation of frequency of SGC with varying geometry is obtained by both finite element simulation and experiments. The most sensitive mode is located, which has wider frequency range by varying the geometry. The polynomial fitting is used to describe nonlinear relation between frequency and geometry. By tuning the geometry, the equivalent stiffness and then resonance frequencies can be manipulated to behave as an active vibration absorber. The vibration reduction experiment of SGC vibration absorbers is investigated. It is found that SGC has better vibration reduction effect in low-frequency band. The experimental results in the current design demonstrate that the vibration reduction effect can reach 94.03% when tuning SCG to the first order main resonance. The dimensions and material parameters of SGC should be altered for specific frequency range and vibration strength.

Facile synthesis of 3D Ni@C nanocomposites derived from two kinds of petal-like Ni-based MOFs towards lightweight and efficient microwave absorbers

Nanoscale ◽  
2021 ◽  
Author(s):  
Pengshu Yi ◽  
Zhengjun Yao ◽  
Jintang Zhou ◽  
Bo Wei ◽  
Ruiyang Tan ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Microwave Absorption ◽  
High Efficiency ◽  
Facile Synthesis ◽  
Microwave Absorbers ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption

The development of lightweight and high-efficiency microwave absorption materials has attracted wide attention in the field of electromagnetic wave absorption. Herein, two kinds of petal-like Ni-based MOFs were grown on...

scholarly journals Frequency response and self-noise of the MET hydrophone

2018 ◽  
Vol 7 (2) ◽  
pp. 443-452 ◽  
Author(s):  
Dmitry L. Zaitsev ◽  
Svetlana Y. Avdyukhina ◽  
Maksim A. Ryzhkov ◽  
Iliya Evseev ◽  
Egor V. Egorov ◽  
...  
Keyword(s):  
Frequency Response ◽  
Experimental Model ◽  
Frequency Band ◽  
Mass Production ◽  
Low Frequency ◽  
Experimental Results ◽  
Noise Model ◽  
Frequency Range ◽  
Molecular Electronic ◽  
Methods And Techniques

Abstract. An electrochemical hydrophone based on the principles of molecular electronic transfer (MET) has been described. The paper presents theoretical and experimental results for the sensitivity and the level of self-noise determination for the MET hydrophone (METH) in the frequency range of 0.02–200 Hz, which determines the fields of acceptance of the devices being developed. An experimental model has been developed by using a force-balancing feedback. Different methods and techniques for its calibration have been developed. The experimental device with 0.75 mV Pa−1 sensitivity flat in the frequency band 0.02–200 Hz has been presented. It has been demonstrated that in the ultra-low-frequency range METH noise could be much lower than the standard Wenz noise model. Easy to produce, cheap and suitable for mass production, the MET hydrophone could be in demand in marine and land acoustic research.

Microwave Behavior of α-Fe/Fe3B/Y2O3 and ε-Fe3N/Y2O3 Resin Composites in GHz Range

2004 ◽  
Vol 449-452 ◽  
pp. 769-772 ◽  
Author(s):  
K. Machida ◽  
J.R. Liu ◽  
M. Itoh
Keyword(s):  
Electromagnetic Wave ◽  
Microwave Absorption ◽  
Resin Composites ◽  
Frequency Range ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Melt Spun

Nanocompositesα-Fe/Fe3B/Y2O3 and ε-Fe3N/Y2O3 were prepared by a melt-spun technique, and the subsequent hydrogenation, oxidation and nitrogenation treatments, respectively. The effective electromagnetic wave absorption (RL<-20 dB) was obtained in a frequency range of 2.7-6.5 GHz on resin composites of 80 wt% α-Fe/Fe3B/Y2O3 powders, with thickness of 6-3 mm; the ε-Fe3N/Y2O3 resin composites exhibited good microwave absorption properties in the 0.6-4.4 GHz range.

Sign in / Sign up

Export Citation Format

Share Document