Electromagnetic wave absorbing materials are of great importance in electromagnetic protection, electronic communication, and military stealth applications. However, achieving the synergistic optimization of high-temperature resistance, lightweight characteristics, and broadband absorption remains a significant challenge. In this work, a perovskite-type solid solution absorbent, (BaxSryLa1-x-y)(TixMn1-x)O3 (BSLTM), was synthesized through a two-step solid-state reaction and subsequently fabricated into a BSLTM/Al2O3 coating using Al2O3 as the substrate. The phase composition and microstructure of the BSLTM/Al2O3 composite coatings were confirmed by X-ray diffraction and scanning electron microscopy analyses. Complex permittivity measurements indicate that the dominant high-temperature loss mechanisms arise primarily from electrical conductivity loss and polarization loss. With a coating thickness of 2.1 mm, the BSLTM/Al2O3 coating with x = 0.6 achieves an effective absorption bandwidth (RL <=-10 dB) of 2.27 GHz in the frequency range of 8.43-10.70 GHz, along with a minimum reflection loss of-22.8 dB at 700 degrees C. By modulating multiple polarization mechanisms to synergistically enhance both dielectric and conductive losses, this strategy imparts the BSLTM/Al2O3 coating with outstanding high-temperature microwave absorption performance, highlighting its strong potential for improving the stealth capability and survivability of aircraft.

Microstructure construction and multicomponent strategies are essential for microwave absorption materials, which require a broad effective absorption bandwidth (EAB, RL < -8dB) and thin thickness. Herein, a resin-based patch filled with Ba3Co2Fe24O41 (Co(2)Z) and carbonyl iron powders (CIP) was prepared using air spraying, where the composited absorbent Co(2)Z@CIP was synthesized by mechanical ball milling. With the mass percentage of the absorbent fixed at 70 wt%, the influence of the mass ratio between Co(2)Z and CIP on microwave absorption was investigated. The composition of Co(2)Z and CIP resulted in a significant reduction in magnetic loss and dielectric loss while minimizing the weakening of magnetic polarization, thus facilitating impedance matching. Under these interactions, the resin-based patch with a Co(2)Z:CIP ratio of 1:1 realized an EAB of 5.6 GHz (7.4-13 GHz) at a thickness of 1.7 mm, covering the whole X band. Furthermore, the EAB could cover the C2 and Ku bands at the thickness of 2.1 mm and 1.3 mm, respectively. RCS simulation demonstrate the excellent signal suppression within a wide range of incident angles. The design strategy effectively meets the requirements of modern radar stealth.

This study reports the in-situ grown ceramic coatings on AZ31 magnesium alloy via a micro-arc oxidation (MAO) process under a constant current mode in an alkaline electrolyte containing alumina sol. Structure characterizations and property analyses were performed, and the related mechanisms were also discussed. The results reveal that aluminum oxide is uniformly dispersed within the coating rather than aggregated within the micropores of the ceramic coating. Moreover, the sizes of the micropores are significantly reduced during the reflow process following discharge breakdown when alumina sol is incorporated into the electrolyte. Compared with the coating without alumina sol (6.12 % porosity), the porosity of the ceramic coating fabricated with 7.5 ml/L alumina sol addition decreases to 1.90 %, demonstrating a pronounced reduction in porosity. Additionally, the ceramic coating prepared with 2.5 ml/L alumina sol exhibits a minimum corrosion current density of 5.342 x 10-9 A/cm2, indicating enhanced corrosion resistance for MAO ceramic coating fabricated using alumina sol modified electrolyte.

Conventional polymer matrix microwave absorbing (MA) composites often struggle to balance lightweight with high load-bearing capacity. Inspired by the bract-shell structure of jackfruit, we introduces an armored shell design on the outer layer of aligned aerogels, significantly enhancing mechanical strength while preserving their intrinsic excellent impedance matching and microwave attenuation. At the microscopic level, a heterogeneous interface structure was constructed by growth of 0D Mo2C on 2D graphite nanosheets (GN). At the macroscopic level, an GN@Mo2C oriented aerogel was fabricated within a modified 3D integrated hollow E-glass fabric using ice-templating. The aerogel was then backfilled with 9802 resin/hollow glass microsphere (HGM) slurry to produce the final GN@Mo2C/E-glass composite. By controlling the supercooling process at different depths within the cold trap, the dispersion of GN@Mo2C in the sodium carboxymethyl cellulose (CMC) framework was optimized, achieving full-band coverage in X-Ku. The synergistic effect of GN@Mo2C interfacial stress dispersion/enhanced force conduction of vertically oriented aerogel sheets/resin-aerogel interlocking and interface modification, the flexural strength of the composite increased from 8.02 MPa to 81.75 MPa, while maintaining excellent mechanical after annealing. Additionally, the composite exhibited outstanding thermal insulation and flame retardancy. This work provides an effective strategy for the integrated MA and load bearing multifunctional composite.

The integration of carbon nanotube (CNT) with magnetic particles offers a highly effective strategy for developing materials with superior electromagnetic (EM) wave absorption performance. In this study, we successfully synthesized coral-like Co/CNT assembly structures via a facile hydrothermal-oxygen assisted chemical vapor deposition (CVD) strategy. Thereinto, CNTs were grown in-situ on coral-like Co, forming well-organized CNT arrays that encapsulate the coral-like Co and realizing the mutual anchoring between coral-like Co and CNT. To elucidate the role of the CVD atmosphere in modulating the morphology and composition of the resulting structures, a systematic investigation was conducted. The results depict that when O2 was introduced, urchin-like Co(CO3)0.5(OH)center dot 0.11 H2O transformed to Co/CNT assembled structures, because O2 suppresses the rapid reduction of the precursor into large Co particles, thereby enhancing the catalytic efficiency of Co and facilitating the in-situ growth of CNT on coral-like Co. Three-dimensional (3D) architecture of the coral-like Co/CNT assembly structure, along with the synergistic interaction between coral-like Co and CNTs, numerous Co-CNT heterogeneous interfaces, and abundant lattice defects, collectively facilitates multiple EM wave absorption mechanisms of coral-like Co/CNT assembly structures-including interface polarization, dipole polarization, conductive loss, magnetic loss, and multiple scattering-thereby significantly enhancing overall EM wave absorption performance. As a consequence, at an optimal thickness of 2.2 mm, the minimal reflection loss (RLmin) of coral-like Co/CNT assembly structures reaches an impressive -39.08 dB, and when the thickness is 1.92 mm, the EAB reaches 4.01 GHz.

Material consist of carbon nanotube (CNT) and magnetic nanoparticles could enhance its electromagnetic (EM) wave absorption performance by integrating the characteristics of relevant materials, showing notable potential in EM wave loss. In this study, an innovative H2-free, low-temperature CVD strategy is developed to rationally design 3D hierarchical assembled Co/CNT structures as high-performance EM wave absorbers, utilizing ethanol (C2H5OH) as carbon source and urchin-like Co(CO3)0.5(OH)& sdot;0.,,H2O nanoparticles as the catalytic precursor. Significantly, in 3D hierarchical assembled Co/CNT structures, Co nanospheres-encapsulating CNTs are in-situ grown on coral-like Co in an array arrangement, which not only facilitates electron transport between the two components but also generates numerous heterointerfaces, thereby enhancing conductive loss, which greatly amplifies EM wave attenuation. Owing to the advantages of special 3D hierarchical assembled structure, abundant heterogeneous interfaces, hybrid of dielectric/magnetic components and coral-like Co-CNT array conductive network, multiple loss modes are manifested in the EM wave absorption process, involving conductive loss, dipole polarization, interface polarization, multiple scattering, magnetic loss, and good impedance matching, boosting EM wave absorption. The graphitization degree of CNTs and the crystallinity of Co are controlled by varying the CVD temperature of 3D hierarchical assembled Co/CNT structure, thereby effectively regulating the EM parameters and EM wave dissipation properties. At a synthesis temperature of 650 degrees C, an EM wave absorption of -31.65 dB and an effective bandwidth of 3.91 GHz are achieved with filler loading of 15 wt%. The preparation of this 3D hierarchical assembled Co/CNT structures just requires a low temperature, obviating the requirement for H2 and nanoscale catalysts. Furthermore, it possesses a distinctive layered assembly configuration and demonstrates superior EM wave absorption performance even under lowloading conditions. Such characteristics render it applicable in the aerospace domain, including scenarios like the absorbing coatings on aircraft surfaces and the absorbents utilized for honeycomb impregnation.

Commercially thin microwave absorbing materials (MAM) often rely on a high proportion of magnetic metal powder as absorbents, leading to excessive loss, impedance mismatch, and high density. LiNb0.8Ti0.25O3, which has attracted attention in the fields of microwave devices and microwave communications due to its high microwave dielectric constant and low loss characteristics, was therefore incorporated as a high-permittivity phase with traditional microwave absorbers to effectively tailor the complex permittivity of the composites. In this study, LiNb0.8Ti0.25O3 and carbonyl iron powders were composited, and resin-based MAM coatings were prepared via air spraying. The performance of the coating was investigated under the premise of significantly reducing density. Electromagnetic parameters, hysteresis loops, and electromagnetic simulations were employed to comprehensively analyze the electromagnetic response mechanisms and absorption performance of the materials. The combination of dielectric powders and magnetic powders enabled tunable magnetic loss and narrowband dielectric resonance while exhibiting specific dielectric dispersion. This approach facilitated the optimization of impedance matching, achieving absorption peaks at specific thicknesses and frequencies (e.g., RLmin of -53.51 dB at 4.28 GHz with a thickness of 2.9 mm). Additionally, the synergy between dielectric and magnetic responses resulted in an enhanced effective absorption bandwidth, reaching 5.77 GHz (12.23-18 GHz) at 1.2 mm and covering the entire Ku-band. This study provides valuable insights for researchers aiming to achieve further breakthroughs in absorption performance through the incorporation of functional composites based on metallic powders and other strong electromagnetic response powders.

High-temperature microwave-absorbing materials are crucial for achieving radar stealth in high-speed equipment. In response to this necessity, we investigated xLa0.9Sr0.1MnO3/(1-x)Ba3.75La9.5Ti18O54 composite ceramics under variable temperatures, where x ranges from 20-50wt%. X-ray diffraction analysis indicates the coexistence of La0.9Sr0.1MnO3 and Ba3.75La9.5Ti18O54 when x ranges from 20-30wt%, transforming into a perovskite-structured solid solution with a higher proportion of La0.9Sr0.1MnO3. Variable-temperature direct current conductivity reveals a controllable transition from dielectric behavior to semiconductor behavior, resulting in the dielectric properties of composite ceramics shifting from low-loss to high loss characteristics. For x values ranging from 20wt% to 40wt%, there consistently exists a corresponding temperature and frequency range ensuring specific absorption performance. Notably, the composite ceramic with x=30wt% and a thickness of 1.1mm demonstrates an effective absorption bandwidth (RL<-10dB) of 1.75GHz within the temperature range of 400-600℃. These findings suggest that composite ceramics comprising La0.9Sr0.1MnO3 and Ba3.75La9.5Ti18O54 hold promise as high-temperature microwave-absorbing materials.

High-temperature microwave-absorbing materials are crucial for achieving radar stealth in high-speed equipment. In response to this necessity, we investigated xLa(0.9)Sr(0.1)MnO(3)/(1-x)Ba3.75La9.5Ti18O54 composite ceramics under variable temperatures, where x ranges from 20 to 50 wt%. X-ray diffraction analysis indicates the coexistence of La0.9Sr0.1MnO3 and Ba3.75La9.5Ti18O54 when x ranges from 20 to 30 wt%, transforming into a perovskite-structured solid solution with a higher proportion of La0.9Sr0.1MnO3. Variable-temperature direct current conductivity reveals a controllable transition from dielectric behavior to semiconductor behavior, resulting in the dielectric properties of composite ceramics shifting from low-loss to high-loss characteristics. For x values ranging from 20 wt% to 40 wt%, there consistently exists a corresponding temperature and frequency range ensuring specific absorption performance. Notably, the composite ceramic with x=30 wt% and a thickness of 1.1 mm demonstrates an effective absorption bandwidth (RL<-10 dB) of 1.75 GHz within the temperature range of 400-600degree celsius. These findings suggest that composite ceramics comprising La0.9Sr0.1MnO3 and Ba3.75La9.5Ti18O54 hold promise as high-temperature microwave-absorbing materials.

Micron-carbon particles with polymorphous concave polyhedron have been easily prepared via high-efficiency spray drying-carbonization process, which is aimed at boosting dielectric polarization toward the feature of high the real part of the complex permittivity accompanied with low level dielectric loss for achieving ultrathin absorber. In addition, the effect of geometry on the microstructure and microwave absorption (MA) performances was systematically studied for the first time. A minimum reflection loss (RLmin) of -55.07 dB under ultrathin thickness of 1.23 mm and a broad effective absorption bandwidth (<-10 dB) of 4.0 GHz at 1.3 mm were obtained for composites filled with polymorphous concave polyhedral carbon particles, meanwhile the loading contents have been reduced from 30 wt% spherical filler to 22.5 wt% polymorphous concave polyhedral filler. Optimized MA performance with strong loss and ultrathin thickness has been identified as attenuation mechanism dominated by interference cancellation and assisted by dielectric loss for the first time. This work not only provides an insight to realize engineering applications of carbonaceous absorbents but also reveals the intrinsic attenuation mechanism of microwave absorbing materials.

To improve crack propagation issues of bituminous mixtures in an eco-friendly way, steel slag (SS) and waste ferrite were partially substituted for aggregate and filler in the bituminous mixtures to enhance the self-healing performance (SHP) of the mixture through microwave heating (MH). Firstly, the electromagnetic parameters of ferrite filler (FF) and SS were tested by the vector network analyzer. Secondly, the thermal conductivity (TC) of ferrite filler bituminous mixtures (FFBM) and steel slag bituminous mixtures (SSBM) was tested based on the transient plane source. Subsequently, the MH surface temperature was measured on FFBM and SSBM, and the MH efficiency and uniformity were analyzed. Finally, the SHP of two types of bituminous mixtures under different conditions was analyzed. The results revealed that both FF and SS have significant magnetic loss, and the absorption performance of FF is better at the same frequency and thickness. The TC of SSBM is higher than FFBM, but due to the porous characteristics of SS, it tends to stabilize. The MH efficiency of FFBM is lower due to its volume ratio, but it has better uniformity. The self-healing rate of SSBM is higher at 40 s MH time, but FFBM can obtain a higher self-healing rate by extending the heating time. This work contributes to understand the difference between different types of suction materials self-healing of bituminous mixtures under MH.

Reduced graphene oxide (rGO) nanosheets and ZnO filled ZnAl2O4 composites (rGO/ZnO/ZnAl2O4 composites) were fabricated by hot-pressing sintering process in-situ reactions for the purpose of microwave absorption applications. The effects of ZnO and rGO content on the mechanical, dielectric and microwave absorption properties were systemically investigated. The results show that the porosity and microhardness increase with increasing the absorbent content, while the flexural strength presents an opposite trend. In addition, the dielectric properties present an overall increase trend with increasing the absorbent content. Because of the favorable impedance matching and the optimal microwave attenuation, the rGO/ZnO/ZnAl2O4 composite with 1 vol% rGO and 8 vol% ZnO demonstrates minimum reflection loss of -44.5 dB at 10.1 GHz and effective ab-sorption bandwidth of 3.8 GHz in 8.2-11.8 GHz and 12.2-12.4 GHz as the thickness is 2.2 mm. The synergistic effects of interfacial polarization, dipole polarization, conductance loss, and multiple scattering result in the outstanding microwave absorption properties for the investigated rGO/ZnO/ZnAl2O4 composite, which indicates their potential candidates for the microwave absorbing materials with broad bandwidth and strong absorption.

As a preventive maintenance method, microwave self-healing is an effective method for early repairing small cracks in asphalt mixture, reducing maintenance costs and prolonging service life. However, asphalt mixtures containing aggregate-type wave-absorbing agents have a common problem of uneven heating. Asphalt mixture was prepared by partially replacing the limestone filler with ferroferric oxide (Fe3O4, FO), and the healing performance under microwave heating was studied. The rheological properties of asphalt mortars with FO and the fluidity of conventional asphalt mortars were studied by dynamic shear rheometer (DSR). Then, the magnetostatic properties and electromagnetic parameters of FO fillers were analyzed by vibrating sample magnetometer (VSM) and vector network analyzer (VNA). Finally, the semicircular bending (SCB) samples were studied by the breaking-microwave healing experiment. The results show that FO fillers have obvious ferromagnetism, and they mainly rely on magnetic loss for energy conversion. FO is beneficial to the improvement of high temperature rheological properties of asphalt mortar but not to low temperature rheological parameters; the replacement ratio of FO to limestone filler should not exceed 50%. The flow healing behavior of asphalt mortar is greatly affected by temperature, which is the fundamental reason for the self-healing of asphalt mixture. The heating efficiency of the asphalt mixture containing FO filler is significantly improved under microwave irradiation; the FO filler has a slightly negative effect on the initial strength of SCB samples but can significantly improve the healing rate after microwave.

Transition-metal phosphides have been investigated for microwave absorption applications owing to their excellent conduction loss and magnetic property. In this study, novel composites comprised of porous Al2O3 matrix loaded with FexCoyP (FexCoyP/Al2O3) were prepared by vacuum impregnation, hydrothermal, and low -temperature phosphatizing methods. The experimental results show that FexCoyP is uniformly deposited on the surface of porous Al2O3 ceramic, and the FexCoyP transforms from needle-like to particle-like structures as the Fe/Co ratio increases from 1:3 to 3:1. The minimum reflection loss (RLmin) of FeCo3P/Al2O3 composite reaches-26.19 dB at 12.4 GHz with a matching thickness of 2.6 mm, and the maximum effective absorption bandwidth (EAB) achieves 4.2 GHz in the whole X-band at 3.2 mm thicknesses. This study confirmed that the porous FexCoyP/Al2O3 composites are potential candidates for microwave absorption applications, and their microwave absorption properties can be enhanced by adjusting the ratio of Fe to Co.

Modern electronic information technology has led social life into inevitable electromagnetic pollution, making microwave absorbing materials more and more important. Herein, dielectric-conductive ZnO/C hybrid composite absorbents were prepared by two-step carbonization with ZnO powders and glucose as critical materials. The electrical conductivity, complex permittivity, and reflection loss were analyzed to study the dielectric and microwave absorption properties. Results show that the prepared ZnO/C composite absorbents exist in the form of rod-like ZnO dispersed in the irregular block carbon, and the complex permittivity of the composite absorbents can be adjusted via varying the carbonization temperature. The minimum reflection loss of −25.64 dB is achieved at 1.8 mm thickness for the composite absorbent with 50 wt.% absorbent content as the final carbonization temperature is 750 °C, and the optimum effective absorption bandwidth is 2.21 GHz at 9.64–11.85 GHz. The excellent microwave absorption properties of ZnO/C composite absorbents are attributed to the combination actions of dipole polarization, conductance loss, and interface polarization, which is significant for the purposeful design of superior microwave-absorbing materials with dielectric and conductive absorbents.

Magnesium alloy is an important engineering material with many excellent physical and chemical properties,which has broad application prospects in the fields of aerospace, transportation, electronic communications, biomedicine,energy, etc. However, the application of magnesium alloy is limited by its high chemical activity, so surface treatment is required to avoid corrosion. Micro-arc oxidation（MAO） leads the working area from the Faraday area to the high-voltage discharge area,which overcomes the defects of anodic oxidation and greatly improves the overall properties of magnesium alloys. Based on the research status in China and abroad, the effects of electrolyte, particle additives and electrical parameters（current mode, voltage,current density, duty cycle, frequency and oxidation time） on the corrosion resistance, wear resistance and biological properties of the films were introduced emphatically. Then, key issues such as regulation orientation, ceramic film toughening,performance matching optimization and energy utilization were proposed. In addition, the solutions adopted by the researchers to the above problems were discussed, and the rationality was analyzed accordingly. Finally, in view of the existing problems,the future development of MAO technology of magnesium alloys was discussed.MAO films are known for higher thickness, dense structure and ceramic phase, which usually shows excellent corrosion resistance and wear resistance compared to other types of films. However, due to the film-forming characteristics of MAO process, there is inevitably a certain porosity in the ceramic films. To increase film density, researchers have explored the use of nanoparticles in the electrolyte, which can be deposited onto the film by electrophoretic adsorption or electromigration under a strong electric field. In fact, ceramic films can be brittle and prone to fatigue and peel off during wear. To address this issue,increasing the toughness can enhance the energy absorption capacity of the films and prevent the rapid crack propagation. At present, there has been little research on the toughening of magnesium alloy ceramic films, which can be deepened in the future.Studies were also made to introduce a lubricating phase, such as graphite, to enhance anti-friction performance of the films. It has been found that the single factor experiment may not accurately capture the influence of process parameters on films, which is due to the interaction between variables. Therefore, the relationship between the process parameters and the film properties is nonlinear, and when a certain critical value is exceeded, the film properties will deteriorate. In addition, magnesium alloys are commonly used in biological applications, where there are also checks and balances between biological properties, such as degradation rates and bacterial inhibition. Therefore, optimizing the matching between properties is key to improving the overall performance of the films.Due to the complexity of MAO process, there is no complete explanation of the film formation mechanism. Thus, basic research should be further strengthened to explore the thermodynamics and kinetics of film formation. In recent years, the research direction tends to solidify, and there is little research with substantial innovation. Therefore, it is urgent to establish a richer and more scientific research system on the basis of the previous work. Last but not least, energy consumption is also an important factor that can hardly be ignored in future industrialization. Reducing energy consumption without sacrificing the quality of the film will both reduce costs and uphold the concept of sustainable development.

The heterostructure and hierarchical morphology of carbonaceous absorbents play an important role in the construction of high-performance electromagnetic wave absorbing materials. Herein, novel micron-scale hard carbon particles with morphology heterogeneity were developed as lightweight superior electromagnetic wave absorbents via a facile and ecofriendly process. The as-prepared hard carbon particle composed of pseudographite and a highly disordered region shows a unique heterostructure. Concurrently, constructing a multilevel geometric shape and size can cause a decrease of the percolation threshold and an excellent balance between polarization and conduction loss, which enhances the electromagnetic wave absorption significantly. The composites (thickness d = 2.36 mm) filled with morphology-heterogeneity hard carbon particles (15 wt %) achieve an excellent electromagnetic wave absorption with a minimum reflection loss of -78.0 dB at 10.2 GHz and effective absorption bandwidth (<-10 dB) of 3.1 GHz (8.8-11.9 GHz). Compared to the traditional carbonaceous absorbents with complex microstructures and/or multiple chemical components, this work presents a feasible idea for the development of an efficient carbonaceous absorbent to realize practical applications.

Ethnopharmacological relevance: Hard antler extract, a well-known traditional Chinese medicine, has diversified functions of immune-modulatory, anti-oxidation, anti-inflammatory and anti-stress. However, the effect of HAE on hormone receptor-positive breast cancer has not been studied.Aim of the study: To investigate the anti-tumor effects of hard antler extract on MCF-7 cells and 7,12 dimethylbenz (a) anthracene (DMBA)-induced mammary tumors and to explore its potential mechanism.Methods: We tested the effects of HAE prepared by sequential enzymatic digestion on the hormone receptor-positive breast cancer cell lines MCF-7. Cell viability, mammosphere formation, migration, invasion and signaling were measured. We also tested the effects of HAE on breast cancers induced in rats by intragastric administration of DMBA, measuring the time of tumor occurrence, tumor size, number and body weight of rats. In addition, the influence of HAE treatment on extracellular matrix, epithelial-mesenchymal transition (EMT) process and the PTEN/Akt signaling were examined by immunohistochemistry, immunofluorescence, RT-PCR and Western blot assays.Results: We found out that HAE inhibited the number of cancer stem cells (CSCs), as well as the migration and invasion of breast cancer cells. HAE also promoted significant increases in E-cadherin expression accompanying reduced expression levels of matrix metalloproteinase (MMP)-9, Vimentin, Slug, Snail and Twist. Besides these, HAE restrained tenascin-C (TNC), integrinαVβ1 expression, and the growth of tumor without any liver and lung injury.Conclusion: Our study showed that HAE inhibits hormone receptor-positive breast cancer through PTEN/AKT signaling pathways. In addition, HAE may inhibit hormone receptor-positive breast cancer by TNC/integrinαVβ1 signaling in the extracellular matrix (ECM).