Electromagnetic Waves Research Articles

Effects of rock pore and micromorphology on electromagnetic radiation characteristics

Electromagnetic radiation (EMR) is a crucial tool for monitoring and early warning of underground engineering disasters. Investigating the inherent pore characteristics of rocks is essential for a comprehensive understanding of the EMR phenomenon.. The EMR was monitored during various types of rock splitting failures. The pore structure and micromorphology of rocks are studied using quantitative methods such as mercury intrusion porosimetry, fractal analysis, and the Gray Level Co-occurrence Matrix (GLCM). Results indicate that the fractal dimension of red sandstone is significantly lower than the other three rocks. The fractal complexity increases sequentially from red sandstone to marble, granite, and limestone.. As the fractal dimension decreases, the signal waveform characteristics of the four rocks become more complex before the main fracture, with a significant increase in signals during the compaction and elasticity stages.. Higher fractal dimensions lead to a shift in energy and count from elasticity stage to the post-peak stage. The main fracture amplitudes of the four rocks generally exhibited a consistent pattern, following the sequence of granite > marble > limestone > red sandstone. The main fracture amplitude decreases with increasing complexity of the rock's pore micromorphology. Rock pore characteristics affect frequency domain characteristics by influencing rock strength and crack expansion. An increase in the average pore diameter tends to decrease both the main and center frequencies.

Effect of interface structure on microwave absorbing performance and oxidation behavior of SiCf/mullite composites

Interface structure of ceramic matrix composite is crucial for flexural strength, fracture toughness, electromagnetic wave (EMW) absorbing properties, and oxidation resistance. This work prepared the multi-layer C-SiC interfaces in SiCf/mullite composites via a precursor infiltration-pyrolysis process (PIP) combining ball-milling dispersion. The effects of the interface thickness on the flexural strength, toughness, and EMW absorbing performance were investigated. The result shows that the SiCf/mullite with a thickness (t) of 0.32 μm C-SiC interface exhibits excellent flexural strength (154.66 MPa) and strong absorbing performance with a broad effective absorption bandwidth (EAB, RL ≤-10 dB) covering the whole X-band. The composite with a 1.35 μm C-SiC interface significantly improves up to 32.01 MPa·m1/2 in fracture toughness. The oxidation behaviors of SiCf/C-SiC/mullite under 1000°C were also investigated by analyzing the cross-section morphology and fracture models. The C-SiC interface isolated the SiO2 generated on the fiber from the Al2O3 in the matrix. The flexural strength retention rate of the oxidized composite is 82% when the thickness of C-SiC interface is 0.32 μm.

Regulating the phase composition and microstructure of Fe3Si/SiC nanofiber composites to enhance electromagnetic wave absorption

The rational introduction of multi-components to fabricate electromagnetic wave absorbing (EMA) materials with synergistic conductive/dielectric/magnetic losses promises lightweighting and excellent EMA performance, but it remains a challenge. In this work, multicomponent Fe3Si/SiC nanofibre composites with network structure were constructed by electrostatic spinning method and in-situ carbothermal reduction strategy. Design of microstructures and multicomponent modulation by controlling the carbothermal reduction temperature. As a result, the presence of a large number of non-homogeneous interfaces, three-dimensional (3D) conductive network structures and defect structures in Fe3Si/SiC nanofibre composites induces a combination of multiple loss mechanisms that significantly improve the EMA performance. When the filling amount of Fe3Si/SiC in the paraffin transmission matrix is 20 wt%, the maximum effective absorption bandwidth (EABmax) of the fabricated material reaches 5.84 GHz with a thin thickness of 2.02 mm. Moreover, the minimum reflection loss (RLmin) value at 10.96 GHz is as low as −67.57 dB. Meanwhile, the radar cross-section (RCS) simulation verifies that the F-4 peak RCS is reduced to −30.37 dB in the range of −60°<θ < 60°. It indicates that the Fe3Si/SiC nanofiber composites have a good radar-wave dissipation capability in practical applications. In summary, the comprehensive performance of lightweight multicomponent Fe3Si/SiC nanofiber composites can meet the new application requirements and is expected to become an emerging multifunctional wave-absorbing material suitable for harsh environments.

Effect of entropy evolution on electromagnetic response mechanism of carbon-coated medium- and high-entropy oxides

Metal oxides have attracted much attention due to their potential in electromagnetic wave absorption. However, the inherent energy dissipation capabilities of low-entropy metal oxides pose challenges in designing materials with optimal entropy levels. The regulation of entropy structure is anticipated to facilitate the development of novel electromagnetic functional materials featuring abundant active sites, adjustable specific surface area, stable crystal structure, unique geometric compatibility, and distinctive electronic structure. This study compared the electromagnetic loss performance of low, medium, and high entropy metal oxides in carbon matrices. As entropy increases, the number of phases expands, leading to enhanced interface polarization losses and improved impedance matching. However, further increases in entropy result in performance decline due to lattice distortions and mismatches in dielectric constant and magnetic permeability. Experimental data and theoretical analysis reveal that performance enhancement in medium-to high-entropy metal oxides is attributed to their unique morphology and the synergistic effects of multiple metal components, which enhance interfacial and defect polarization mechanisms. Heterogeneous interfaces and lattice defects provide additional polarization sites, aiding in the conversion of electromagnetic energy into heat. The presence of intermediate phases effectively absorbs and dissipates electromagnetic waves, thereby enhancing the overall absorption capability.

In-Situ Surface Modification of Nickel Mesh for Superior Electromagnetic Interference Shielding

Metal mesh, with its inherent conductivity, transparency, and flexibility, has proven to be an exceptional choice for high-performance reflection-dominated electromagnetic interference (EMI) shielding materials, due to its multifunctionality and wide applicability. However, the development of metal-based absorption-enhanced EMI shielding materials characterized by high absorption and low reflection is crucial but remains challenging. Herein, we introduce a novel surface modification strategy for nickel mesh (NM) aimed at augmenting its surface electromagnetic wave absorption through electrochemical surface microstructure alteration and subsequent wet chemical sulphuration. This approach leverages the multiple reflections within the microporous structure and the impedance matching enhancement provided by the magnetic sulfided nickel layer, resulting in the sulphur-treated porous NM (Ni3S2-PNM) achieving an outstanding average EMI SE of 59.6 dB across a broad frequency range of 4 to 40 GHz. The surface electromagnetic wave absorption rate of Ni3S2-PNM has increased from under 1% for unmodified NM to over 60%, significantly reducing the re-reflection of electromagnetic waves back into free space (the average SER value decreases from about 20 dB to 2.2 dB). Characterized by its simplicity and cost-effectiveness, this in-situ surface modification method on bulk industrial-grade NM, enhancing electromagnetic shielding, presents a promising avenue for wider application in electromagnetic protection.

Void fraction measurement of slug flow using electromagnetic wave phase sensor based on optimized hybrid dielectric constant

The void fraction is one of the basic parameters to study the gas-liquid two-phase flow, which has great significance to the transportation of oil pipelines and the design of nuclear reactor cooling towers. However, due to the complex and variable nature of gas-liquid two-phase flow, accurately measurement of the void fraction has remained a challenging task in both scientific research and industrial applications. According to the principle of electromagnetic wave propagation, a coaxial line phase sensor was designed, a hybrid dielectric constant model based on the homogeneous flow was established and a void fraction based on hybrid dielectric constant model was proposed. The experiments were carried out on the high-precision gas-liquid two-phase flow simulation experimental setup at Hebei University, China (70 data points), and the void fraction model was inspected and verified. Five typical hybrid dielectric constant correlations were compared. Introducing the frequency weight, optimizing the hybrid dielectric constant model based on the Series – Parallel correlation, a new void fraction prediction correlation of slug flow was proposed and evaluated. The results indicated that the mean absolute percentage error (MAPE) of the new void fraction correlation is 1.02 % and the all of the relative errors are within ±5 % error band.

Multi-material fused deposition modelling of structural–functional integrated absorber with multi-scale structure possessing tunable broadband microwave absorption

Designing and manufacturing advanced structural microwave absorbers is one of the most feasible methods to address the growing electromagnetic stealth and protection challenges in both military and civilian domains. To this end, under the application context of structural–functional integration, a series of nanocomposites with varying ratios were prepared using multi-walled carbon nanotubes (MWCNTs) and inexpensive thermoplastic polypropylene as raw materials. The dispersion of nanofillers, rheological properties, thermal properties, and mechanical properties were evaluated. The research found that the impedance matching factor of the electromagnetic wave absorbers plays a more critical role in determining the material’s absorption capacity compared to the loss factor. Simple structural layering by changing the composition and design can effectively increase the effective absorption bandwidth (EAB) of the absorbers, with microwave attenuation primarily arising from conductive loss, interfacial polarization, dipole polarization, and multiple reflections. Finally, a multi-scale quasi-honeycomb absorber was fabricated using multi-material 3D printing with a structured design. Both simulation and experimental results showed consistent trends, demonstrating low sensitivity to the incident azimuth angle. This research features simplicity, low cost, and strong design capability, providing a new strategy for the preparation of functionally graded materials with potential applications in electromagnetic wave absorption.

Wireless transmission method of electromagnetic wave of cross screw signal

Abstract Based on the near-bit azimuthing gamma measuring instrument developed by Changqing Drilling Company, this paper uses comsol multiphysics(COMSOL) numerical simulation software to build the electromagnetic wave wireless transmission model of cross-bolt signal while drilling. By using finite element method and a large amount of calculation and analysis, the influence law of source distance, drill wire conductivity, borehole and mud conductivity and other parameters on the response characteristics is obtained. The simulation modeling method presented in this paper and the conclusions obtained have important guiding significance for further optimizing and upgrading the near-bit wireless short-pass device and better understanding and mastering the signal transmission law of this kind of instrument.

Defect design and vacancy engineering of NiCo2Se4 spinel composite for excellent electromagnetic wave absorption

Vacancy engineering presents an appealing method for modifying the electronic structure of spinel architectures. However, based on well-defined vacancy concentrations, how to design anionic vacancies to modulate electromagnetic parameters as well as electromagnetic wave absorption (EMA) properties is less studied. Here, NiCo2Se4 spinel structures were prepared using different selenization methods, and the Se vacancy defect concentration was controlled by changing the annealing temperature, thus regulating the EMA properties. Among them, the design of the hollow structure effectively enhanced the EMA performance. Moreover, the increase of Se vacancy concentration increases the conductivity loss while regulating the electronic structure, and also acts as an unsaturated site to induce the formation of dipoles to optimize the polarization loss. The effective absorption bandwidth (EAB) of NiCo2Se4-130 reaches 8.48 GHz at 2.4 mm at the highest Se vacancy concentration. This work establishes a direct relationship between vacancy concentration and the electromagnetic wave dissipation capability, offering valuable insights for the development of advanced EMA materials.

The first results of the hydrogen cyanide (HCN) interferometer measuring experimental research apparatus for electromagnetic science (ERAES) for hypersonic vehicle plasma in near space.

The formation of a plasma sheath on the surface of spacecraft or satellites during high-speed atmospheric entry is a significant factor that affects communication and radar detection. Experimental research apparatus for electromagnetic science can simulate this plasma sheath and study the interaction mechanisms between electromagnetic waves and plasma sheaths. Electron density is a crucial parameter for this research. Therefore, in this paper, a HCN heterodyne interferometer has been designed to measure the electron densities of the device, which range from 1 × 109 to 3 × 1013cm-3 and the pressure ranges from 50 to 1500Pa. The light source is a HCN laser with a wavelength of 337 µm, which exhibits higher spatial resolution compared to microwave interferometers. The interferometer is configured as a Mach-Zehnder interferometer, which generates an intermediate frequency through the Doppler shift achieved by a rotating grating. The spatial and temporal resolution of the HCN interferometry reach ∼14mm and 100 µs, respectively. Antenna-coupled ALGaN/GaN-HEMT detectors have been utilized, as they possess higher sensitivity-with a typical reduction factor responsivity of around 900 V/W-than VDI planar-diode Integrated Conical Horn Fundamental Mixers in HCN interferometry. Recently, the initial results of the HCN interferometer designed for ERAES have been obtained during an experimental campaign, demonstrating a phase resolution of up to 0.04π.

Facile process for cost-effective layer-by-layer rGO/SiO2 structure for high microwave absorption

This study introduces a cost-effective and eco-efficient method for fabricating an advanced microwave absorber using a layer-by-layer rGO and SiO2 structure. The rGO/SiO2 composite, synthesized via modified Hummer's and Stöber methods, demonstrates remarkable microwave absorption properties. The resultant porous structure, characterized by an SBET of 294.89 m2/g, enables multiple reflections and scatterings of electromagnetic waves. At a sample thickness of 3.8 mm, the material achieves a reflection loss (RL) of −47.43 dB at 12.56 GHz and an effective absorption bandwidth (EAB) of 11.04 GHz. For a 6 mm thick sample, an exceptionally high EAB of 12.72 GHz is observed, maintaining a high RL of −42.32 dB. These results demonstrate that the rGO/SiO2 material is a promising candidate for applications in electromagnetic wave absorption, offering a simple, scalable solution for mitigating electromagnetic pollution and enhancing military stealth technologies.

Preparation and research of high electromagnetic wave transmission type concrete in 5G frequency band

In urban areas with many buildings, the transmission of 5G signals can be greatly absorbed or reflected, leading to decreased effectiveness of transmission. To address the issues mentioned above, the functional admixture formed by the mixture of nanocrystalline cellulose (NCC) and diammonium hydrogen phosphate (DAP) is added into concrete in this study, the electromagnetic transmission performance (ETP) and mechanical properties of concrete are enhanced simultaneously for the first time, and the electromagnetic transmission coefficient of concrete is doubled. When NCC and DAP are mixed, the electromagnetic transmission coefficient of concrete improved by 117.65%-124.35%, among which, when 0.5wt% DAP and 4wt% NCC are mixed, the electromagnetic transmission coefficient of concrete is the highest, and some frequency bands are as high as 70%, meeting the requirements of electromagnetic wave transmitting materials. In addition, the compressive strength of concrete containing 4wt% NCC and 0.5wt% DAP increases by 24.3% compared to concrete containing only 4wt% NCC.

Multi-heterogeneous interfaces boost dielectric polarization in PBA-derived Co/MnO@NC ternary composites for electromagnetic wave absorption

The elaborate construction of multi-component composites has been deemed as a promising strategy to enhance dielectric polarization response capability in the preparation of highly efficient microwave absorbers. However, the rational design and integration of homogeneous composites with diverse components continues to pose a great challenge. Herein, we propose a straightforward self-assembly-carbonization strategy for fabricating Co/MnO@NC ternary composites derived from CoMn-Prussian Blue Analogous precursors, featuring enriched heterogeneous interfaces and balanced magneto-electric coupling synergy. The ternary composites effectively introduce diverse dissipation mechanisms, including interfacial polarization behavior originated from the constructed heterogeneous interfaces, dipole polarization relaxation triggered by atomic defects, and optimized magnetic loss ability from well-dispersed metallic Co species. Benefiting from these advantages, the Co/MnO@NC composites demonstrate superior electromagnetic wave absorption performances, with a minimum reflection loss value of -61.37 dB at the thickness of 3.5 mm and effective frequency absorption bandwidth of 6.32 GHz, covering the full Ku-band. Furthermore, power loss density and radar cross-section simulations validate that the Co/MnO@NC ternary composites possess exceptional microwave signal attenuation abilities, with a maximum radar cross-section reduction value of up to 27.98 dBm2 at 0°. Such outstanding absorption properties exceed those of most currently reported ternary composites and exhibit significant potential to replace conventional ferromagnetic-based absorbers. This work offers a straightforward strategy to fabricate ternary composites with excellent electromagnetic wave attenuation properties and sheds novel insights into the dissipation mechanisms.

Thermal distribution and viscous heating of electromagnetic radiative Eyring–Powell fluid with slippery wall conditions

The research examines the intricate between Eyring-Powell microfluidic heat transfer, electromagnetic radiation and viscous heating in a Riga slippery device as applied in heat exchangers, cooling systems, biomedical devices, energy generation, polymer processing, and others. The viscoelastic property of the fluid is characterized by the Eyring-Powell Cauchy fluid model with shear-thickening and shear-thinning phenomena that are useful in several heat transport processes and thermal management. The developed governing model is taken from the constitutive relations and conservation principles and solved via an adaptive partition weighted residual method. The essential fluid term sensitivities are systematically investigated on the flow and thermal distribution characteristics. An appropriate validation and comparison of results is done and found to agree quantitatively, this confirmed the correctness of the presented outcomes. The results reveal the significant impact of the thermofluidic terms interaction on the viscous flowing fluid and thermal behaviour. As seen, slip conditions momentously increase the flow rate gradients for about 1.7% to 2.4% close to the boundary wall and consequently raise the microfluidic thermal propagation rates with 3.7% non-Newtonian fluid and thickness of the boundary layer. Moreover, the thermal gradient and distribution complexities are modulated within the fluid regime due to radiation and Lorentz force.

Recent Updates on the Management of Split-thickness Skin Graft Donor Sites.

This article is a narrative review of split-thickness skin graft donor site (STSG-DS) management since the international guidelines were created in 2018. Although many new interventions have been developed, there is a lack of quality, multicentered clinical trials to produce updated evidence-based recommendations. Electronic databases, including Google Scholar, Web of Science, Medline, and PubMed, were searched by two independent researchers for literature regarding STSG-DS management published from 2018 through 2022, using specific terms in the text, title, and abstract. The primary endpoint assessed was STSG-DS healing, as measured by wound epithelialization. Thirty-one articles were selected, including three systemic review/meta-analyses, five case series, 14 randomized controlled clinical trials, six observational studies, and three nonrandomized trials. Novel interventions for STSG-DS management included in this article describe applications of human amniotic membranes, acellular dermal matrices, cell suspensions and growth factors, biomaterials, electromagnetic radiation, and natural products. Various interventions have shown promise for STSG-DS management since the creation of the 2018 international guidelines; however, studies with more standardized protocols and endpoints are needed to produce up-to-date, evidence-based recommendations and improve outcomes for patients undergoing split-thickness skin grafting.

Millimeter wave radiation to measure blood flow in healthy human subjects

Objective.Peripheral Artery Disease (PAD) is a progressive cardiovascular condition affecting 8-10 million adults in the United States. PAD elevates the risk of cardiovascular events, but up to 50% of people with PAD are asymptomatic and undiagnosed. In this study, we tested the ability of a device, REFLO (Rapid Electromagnetic FLOw), to identify low blood flow using electromagnetic radiation and dynamic thermography toward a non-invasive PAD diagnostic.Approach.During REFLO radio frequency (RF) irradiation, the rate of temperature increase is a function of the rate of energy absorption and blood flow to the irradiated tissue. For a given rate of RF energy absorption, a slow rate of temperature increase implies a large blood flow rate to the tissue. This is due to the cooling effect of the blood. Post-irradiation, a slow rate of temperature decrease is associated with a low rate of blood flow to the tissue. Here, we performed two cohorts of controlled flow experiments on human calves during baseline, occluded, and post-occluded conditions. Nonlinear regression was used to fit temperature data and obtain the rate constant, which was used as a metric for blood flow.Main results.In the pilot study, (N= 7) REFLO distinguished between baseline and post-occlusion during the irradiation phase, and between baseline and occlusion in the post-irradiation phase. In the reliability study, (N= 5 with 3 visits each), two-way ANOVA revealed that flow and subject significantly affected skin heating and cooling rates, while visit did not.Significance.Results suggest that MMW irradiation can be used to distinguish between blood flow rates in humans. Utilizing the rate of skin cooling rather than heating is more consistent for distinguishing flow. Future modifications and clinical testing will aim to improve REFLO's ability to distinguish between flow rates and evaluate its ability to accurately identify PAD.

A clean bamboo-based carbon-iron multi-interface complex for electromagnetic radiation attenuation and thermal insulation

Civilian electromagnetic wave (EMW) absorbers are urgently needed to solve the excessive electromagnetic (EM) radiation energy pollution. Biomass, such as wood and bamboo, has a wide range of sources, is porous, and is suitable for forming functional composites. However, the diverse composition and microstructure directly affect the EM and thermal properties of conversion composites, and the corresponding influencing mechanisms are unclear. Here, a series of iron-containing biochar-based composites (CFBs) were synthesized by in-situ pyrolysis of impregnated flattened bamboo sliced veneers with Fe(acac)3 dimethylformamide (DMF) solutions. The components and microstructures were pre-regulated through moisture-heat coupling softening, flattening and slicing treatments. Excellent EMW absorption performance with a |RLmin| value as large as 33.03 dB was obtained for CFB-0.8 at a fixed thickness of 1.15 mm, along with the widest effective frequency bandwidth as large as 4.08 GHz. Besides, In addition, CFB-0.8 has stable Joule heating performance (0.9V, 79.7 °C), and its in-plane thermal conductivity is 31.4 times that of flattened bamboo (0.62 W m−1 K−1). These are attributed to the rich heterojunction interfaces, electromagnetic attenuation caused by structures (porous structure scattering, nanoscale effects), deep absorption mechanisms caused by defects (lattice defects, electric field concentration, non-uniform carbonization structures), and thermal conversion. This work provides theoretical and experimental data for developing EMW absorption materials and new ideas for the high-value utilization of biomass materials and the continuation of their carbon fixation life.

MOF-derived metal oxides with hollow porous nanocube structure realize ultra-wideband, lightweight, and anticorrosion microwave absorber

High density, skin effect, and environmental instability are significant limitations that restrict the application of metal-based microwave absorbers in achieving lightweight, high performance, and long service life. This study broke from traditional methods for preparing a microwave absorber Mn2O3-Fe3O4@PPy (polypyrrole) by employing an innovative annealing process to convert metal into metal oxide by the introduction of metal organic framework (MOF), which effectively achieving a more lightweight absorber material with hollow porous nanocube structure. Subsequently, PPy was coated onto the metal oxide surface to form a core-shell structure by a situ chemical oxidation synthesis method. The combination of metal oxide of the hollow porous nanocube structure and the core-shell structure formed by highly conductive PPy shell significantly enhanced heterogeneous interfaces and electromagnetic (EM) wave reflection. Excellent dielectric loss and impedance matching contributed evidently to the ultra-wideband EM wave absorption performance. It was demonstrated that, with a filling amount of only 20 wt%, the prepared Mn2O3-Fe3O4@PPy achieved an effective bandwidth (EAB) of 10.0 GHz at a thickness of 3.08 mm, with EABmax reaching 13 GHz. At a filling amount of only 10 wt%, the reflection loss (RL) was −62.13 dB, achieving an EAB of 7.4 GHz at 2.98 mm thickness, with EABmax reaching 11.4 GHz. Furthermore, the proposed strategy incorporating metal oxide and PPy enhanced corrosion resistance with higher charge transfer resistance.

Synergistic effects of nitrogen/oxygen co-doping in 3D mesoporous carbon nanospheres for enhanced microwave absorption

Mesoporous carbon nanospheres have attracted significant attention in the microwave absorption (MA) field due to the broad benefits provided by their mesoporous structure. This study presents a facile hard template strategy to construct distinctive 3D N/O co-doped mesoporous carbon nanospheres (NOCS). The high surface area, abundant mesopores, and high nitrogen (N) doping levels, with proper defects on the surface provide multiple sites to absorb electromagnetic waves (EMW). Mesoporous carbon nanospheres achieve significant reflection loss (RL) of −48.19 dB and extensive effective absorption bandwidth (EAB) up to 5.52 GHz. Moreover, computer simulation technology (CST) demonstrated that all simulated Radar cross-section (RCS) values were below 20 dB m2. Thus, this work holds significant promise for effective microwave absorbers using mesoporous carbon nanospheres.

Construction of a highly ordered SiC nanofiber@C fiber heterojunction hybrid with a fuzzy grass-like structure for enhanced microwave absorbing performance

Carbon fibers (Cf) materials with excellent dielectric loss are increasingly attracting attention in the field of microwave absorption. However, the inherent high conductivity of carbon materials usually causes impedance mismatch, which seriously limits their widespread applications in the field of electromagnetic wave (EMW) absorption. To solve this problem, a highly ordered SiC nanofiber@C fiber (SiCnf@Cf) heterojunction hybrid with a fuzzy grass-like structure was fabricated through a simple chemical vapor deposition (CVD) method. Providing a heterogeneous interface on the surface of carbon fibers not only improves their impedance matching capabilities but also enhances their interfacial loss capability. As a result, a minimum reflection loss (RLmin) for SiCnf@Cf heterojunction hybrid is −44.04 dB at 13.6 GHz with a thickness of 1.2 mm, and a maximum effective absorption bandwidth (EABmax) is 3.44 GHz with a thin thickness of 1.1 mm. Furthermore, it also exhibits outstanding thermal insulation performance, which make it a potential candidate for heat-insulating applications. And due to its lightweight and soft characteristics, it perfectly meets the needs of wearable flexible absorbing materials. Therefore, this study not only provides a straightforward for preparing EMW-absorbing materials with exceptional performance, but also offers a solution for improving the thermal stability of the carbon-based material.