Preformed carbon nanotube thin films (10-20 microm), or buckypapers (BPs), consist of dense and entangled nanotube networks, which demonstrate high electrical conductivity and provide potential lightweight electromagnetic interference (EMI) solutions for composite structures. Nanocomposite laminates consisting of various proportions of single-walled and multi-walled carbon nanotubes, having different conductivity, and with different stacking structures, were studied. Single-layer BP composites showed shielding effectiveness (SE) of 20-60 dB, depending on the BP conductivity within a 2-18 GHz frequency range. The effects on EMI SE performance of composite laminate structures made with BPs of different conductivity values and epoxy or polyethylene insulating layer stacking sequences were studied. The results were also compared against the predictions from a modified EMI SE model. The predicted trends of SE value and frequency dependence were consistent with the experimental results, revealing that adjusting the number of BP layers and appropriate arrangement of the BP conducting layers and insulators can increase the EMI SE from 45 dB to close to 100 dB owing to the utilization of the double-shielding effect.
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http://dx.doi.org/10.1088/0957-4484/20/41/415702 | DOI Listing |
Nano Lett
January 2025
IBM Research─Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland.
The inhomogeneous magnetic stray field of micromagnets has been extensively used to manipulate electron spin qubits. By means of micromagnetic simulations and scanning superconducting quantum interference device microscopy, we show that the polycrystallinity of the magnet and nonuniform magnetization significantly impact the stray field and corresponding qubit properties. The random orientation of the crystal axis in polycrystalline Co magnets alters the qubit frequencies by up to 0.
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January 2025
Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100190, China.
The terahertz (THz) security scanner offers advantages such as non-contact inspection and the ability to detect various types of dangerous goods, playing an important role in preventing terrorist attacks. We aim to accurately and quickly detect concealed objects in THz security images. However, current object detection algorithms face many challenges when applied to THz images.
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January 2025
Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
In this work, a site-selective functionalization strategy is proposed for modifying fluorescent dyes in the plasmonic nanopore, which highlights building optoelectronic dual-signal sensing interfaces at "hotspots" locations to construct multiparameter detection nanosensor. Finite-difference time-domain (FDTD) simulations confirmed the high-intensity electromagnetic field due to plasmonic nanostructure. It is demonstrated that adjusting the distance between the nanopore inner wall and fluorophore prevented the fluorescence quenching, resulting in more than a thirty fold fluorescence enhancement.
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January 2025
NanoScience Technology Center, Department of Materials Science and Engineering, Department of Chemistry, Renewable Energy and Chemical Transformation Cluster, The Stephen W. Hawking Center for Microgravity Research and Education, University of Central Florida, Orlando, FL, 32826, USA.
Since the explosive growth of state-of-the-art electronics and devices raises concerns about electromagnetic pollution, exploring novel and efficient electromagnetic interference (EMI) shielding materials is desirable and crucial. TiCT MXenes hold significant EMI shielding potential due to their inherent characteristics, including lightweight, metal-like conductivities, unique layered structure, and facile processing. Nonetheless, it remains challenging to fabricate TiCT MXenes-based EMI shielding materials with efficient shielding capability and low reflection.
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January 2025
School of Electrical Engineering, University of Tehran, Tehran, 14179-35840, Iran.
This paper introduces an analytical method for studying power transmission through an infinite array of helical-shaped metal particles in a lossy dielectric medium. While the assessment of composite slabs' transmitted power has been extensively researched in the electromagnetic interference (EMI) shielding field, many studies lack an adequate problem description. The primary inadequacy of these studies is the need for an analytical framework.
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