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In this study, the effects of different silicon carbide (SiC) particle sizes on the viscosity and curing behavior of alumina (Al 2 O 3) ceramic suspensions were thoroughly investigated. The findings revealed that increasing the size of SiC particles led to a noticeable decrease in the viscosity of the suspension. The Al 2 O 3 ceramic suspension with 0.6 μm SiC powder demonstrated a shallower cure depth and wider excess width compared to the suspension with 1.0 μm SiC powder. Sintering tests demonstrated that the properties of the SiC–Al 2 O 3 ceramics improved at higher sintering temperatures. Moreover, a high-performance honeycomb ceramic was successfully designed and fabricated with a porosity and compressive strength of 30.8 % and 188 MPa, respectively. Finally, the SiC–Al 2 O 3 honeycomb ceramics were effectively applied in heat insulation and oil-water separation applications, demonstrating their remarkable capabilities. [ABSTRACT FROM AUTHOR]

The excellent recyclability of SiC foam renders it an ideal catalyst in the field of photocatalytic degradation, however to further improve its photocatalytic efficiency remains a major challenge in current research. In this regard, a honeycomb-like porous SiC foam was successfully constructed through freeze-drying and polymer-to-ceramic derivation method, with two-dimensional Ti 3 C 2 T x nanosheets anchored on its three-dimensional framework. Their photocatalytic performances were evaluated by the degradation of methylene blue (MB) under visible-light irradiation. All Ti 3 C 2 T x /SiC hybrid foams show superior photocatalytic degradation capability compared with SiC foam, with a highest removal rate (adsorption and degradation) reaching 94.4% for TSF-4, denoting an increasement of 50.4%. Even after five cycles, the removal rate remained at 91.4% with only a slightly loss of 3%, suggesting its excellent recycling performance. These desirable results stem from the unique structural design, in which the porous structure facilitates the contact between catalyst and pollutant, while the Ti 3 C 2 T x /SiC heterojunction promotes effective separation of photogenerated carriers. This work paves the way for the development of lightweight, efficient and easily recyclable photocatalyst for wastewater purification. [ABSTRACT FROM AUTHOR]

To establish a universal and convenient mathematical model for predicting static and dynamic performance of composite sandwich structures, a novel three-dimensional equivalent homogenized model (3D-EHM) is proposed based on variational asymptotic method. The multiscale mechanical analysis of composite hexagonal and re-entrant honeycomb sandwich structures is conducted by 3D-EHM, enabling reasonable transmission of mechanical information at different scales and facilitating accurate predictions of mechanical responses in sandwich structures. The comparison analysis with 3D printing experimental results and 3D finite element model results demonstrates that the 3D-EHM exhibits remarkable precision and computational efficiency in forecasting static displacement distributions and higher-order vibration modes, eliminating the need for time-consuming and expensive experiments. Moreover, the effects of the ply angle of the face sheet and core geometric parameters on the effective properties of composite hexagonal honeycomb sandwich structures are systematically investigated. In summary, 3D-EHM is an effective applied mathematical model for designing and analyzing composite sandwich structures, fully combining the systematicity of variational methods and the asymptotic convergence of asymptotic methods. • A novel three-dimensional equivalent homogenized model (3D-EHM) is proposed. • Calculation accuracy and efficiency in predicting mechanical response are high. • Intrinsic connection between microstructure and macroscopic properties is captured. • 3D-EHM facilitates the tailoring and optimization of the sandwich structure. [ABSTRACT FROM AUTHOR]

Silicon oxycarbide (SiOC) ceramics have been used to fabricate microwave-absorbing metastructures, demonstrating impressive absorption capabilities. However, SiOC ceramic metastructures with excellent performance require simple fabrication processes and appropriate mechanical and electromagnetic properties. In this study, a solvent-free photosensitive polysiloxane preceramic was developed by blending methoxy/hydroxy polysiloxanes with acrylates, with a ceramic yield of over 60% after curing using a novel two-step ultraviolet (UV)/thermal method. The composition and microstructure of SiOC ceramics can be designed by controlling the preceramic composition. Dense, crack-free gyroid-shellular shaped triple periodic minimal surface (GS-TPMS) electromagnetic metastructures were fabricated using digital light processing (DLP) 3D printing technology. By designing the porosity of the GS-TPMS structure to 51%, an effective absorption bandwidth that covers the X-band can be achieved at a thickness of 3.1 mm. The honeycomb structure, with a geometric density of 0.69 g/cm3, exhibited a high compressive strength of 107.05 MPa. This paper presents an efficient approach for the prompt and customized fabrication of lightweight ceramic metastructures with outstanding microwave absorption properties. • A solvent-free polysiloxane/acrylate hybrid preceramics is developed for 3D printing. • The UV/thermal two-stage treatment achieved cross-linking curing of the preceramics. • Multiscale design of SiOC ceramics for enhanced microwave absorption properties. • SiOC ceramic metastructures with effective absorption in the X-band are prepared. [ABSTRACT FROM AUTHOR]

Due to the limitations of the Kramers-Kronig relationship, how to achieve ultra-wide effective absorption bandwidth remains a challenge for typical magnetic-dielectric absorbers. In the present work, we have explored the possibility of obtaining ultra-wide absorption bandwidth in FeSiAl composites with help of efficient electromagnetic (EM) simulation software-Computer Simulation Technology (CST). Flaky FeSiAl powders covered by CeO 2 have been prepared, in which EM parameters can be tuned by filling ratio of FeSiAl/CeO 2 in FeSiAl/CeO 2 -paraffin composites. The filling ratio has an effect on impedance matching and EM parameters by the arrangement of particles in the paraffin. The composite with 30 wt% flaky FeSiAl/CeO 2 achieves an effective absorption bandwidth (EAB) of 6.48 GHz and the optimal microwave absorption efficiency of 1499.3 dB GHz/(wt%⋅m) at 1.9 mm. Integrated with a macroscale honeycomb structural design, the FeSiAl/CeO 2 composites based metastructure exhibits broadband microwave absorption with an EAB of 14.224 GHz covering from 3.776 GHz to 18 GHz and reflection loss of-65.61 dB at 8.5 GHz. The excellent performances of the designed absorber are ascribed to multiple loss by integrating EM parameters of flaky FeSiAl/CeO 2 and the geometry parameters of honeycomb metasrtucture. The present work makes flaky FeSiAl/CeO 2 composites possible to achieve broadband microwave absorption. [ABSTRACT FROM AUTHOR]

Peculiarities of sintering of foamy ceramic filters based on submicron aluminum oxide powders with additions of titanium oxide and manganese dioxide nanopowders are considered. The processes of removal of polymeric and binder paraffin material during sintering have been studied. The physical and mechanical properties of the obtained porous permeable filters with a foamy structure were analyzed in details. At a sintering temperature in an air atmosphere of 1350 °C, sufficiently high physical and mechanical properties were obtained, which made it possible to use the developed filters as catalyst carriers for vehicle exhaust gases. Bench comparative tests have shown that ceramic filters with a foamed structure are promising catalysts for afterburning car exhaust gases instead of ceramic honeycomb blocks of catalyst carriers. The developed technology allows reducing the sintering temperature of porous foam ceramic filters to 1350 °C and replacing expensive high-temperature ceramic heaters with cheaper nickel-chromium ones. [ABSTRACT FROM AUTHOR]

A significant challenge in electrolyte-supported solid oxide fuel cells (SOFCs) pertains to the substantial thickness of the electrolyte, resulting in elevated operational temperatures that hinder commercial viability. In this research, we utilized digital light processing (DLP) 3D printing technology to fabricate ultra-thin honeycomb electrolyte-supported SOFCs and subsequently evaluated their performance. Through the use of ultraviolet absorbers, we achieved a shallow curing depth (60.3 μm), which facilitated the creation of ultra-thin electrolyte samples. We investigated the mechanical properties of electrolytes with various honeycomb structures, finding that the square honeycomb structure exhibited the highest mechanical integrity, with an average failure load of 1.01 N. Finally, we assessed the electrochemical performance, observing a substantial power density of 215.4 mW/cm2, representing a twofold increase compared to the 114 mW/cm2 achieved by the same method in a flat primary cell. [ABSTRACT FROM AUTHOR]

Porous honeycomb mullite ceramics were controllably fabricated in-situ using stereolithography 3D printing. The effects of the dispersant type and content on the rheological behavior of the mullite precursor slurry were investigated. Additionally, the influence of the debinding atmosphere (air and argon) on the quality of the samples and formation of cracks was also studied. The results indicated that oleic acid (OA), 3-glycidoxypropylthrimethoxysilane (KH560), and disperbyk (BYK111) displayed the capability to create low-viscosity and highly stable slurries. Among these KH560 was proved to be the most effective. The mullite precursor slurry containing 4 wt% KH560 dispersants exhibited a shear thinning behavior. It displayed a viscosity of 0.26 Pa·s at a shear rate of 30 s−1. The mullite ceramic parts displayed good a dimensional resolution at an exposure dose of 5.47 mJ/cm2. During the debinding process, the printed parts were susceptible to cracking and deformation in air, but remained devoid of defects in argon. When the samples were sintered at 1600 °C, the corundum phase transformed almost completely into the mullite phase. The linear shrinkage values were 5.81%, 6.33%, and 10.26% in the O-X, O–Y and O-Z directions, respectively. [ABSTRACT FROM AUTHOR]

In this study, Al 2 O 3 honeycomb sandwich structures with different core geometries (square, triangular, circular) have been fabricated through an additive manufacturing system based on the stereolithography (SLA) method. The debinding procedure was performed under both nitrogen and air atmospheres. The impacts of the debinding atmosphere and core geometry on the densification and mechanical properties were investigated. The stiffness and flexural strength of the ceramics were examined experimentally using an impulse excitation of vibration technique and a three-point bending test, respectively. The specific stiffness and specific strength of the ceramics were also evaluated, with the core geometries taken into consideration. The outcomes showed that higher densification was achieved when the ceramics were exposed to debinding in nitrogen. The stiffness values were found to be similar for the same debinding condition within the honeycomb sandwich structures, irrespective of the core geometry. Notably, the highest specific stiffness (98 MNm/kg) was achieved for the samples subjected to debinding in nitrogen with a square core geometry. Furthermore, ceramics with square cores for debinding in a nitrogen atmosphere also demonstrated the highest performance in terms of specific strength (110 kNm/kg) within the honeycomb structures. This study demonstrated that Al 2 O 3 honeycomb sandwich structures with square cores may be suitable candidates for lightweight-structure demanding applications. [ABSTRACT FROM AUTHOR]

Vitrified-bond diamond composites are materials commonly used for grinding wheels in the grinding process of silicon wafer production. In this study, the mechanism of the in situ honeycomb structure formation in the sintering process of composite materials was explored by changing the binder content without adding a pore-forming agent.The results show when the content of vitrified bond is 55 wt%, the in situ honeycomb structure forms, resulting in a porosity of 60.68 % and bending strength of 23.03 MPa.The X-ray diffraction (XRD), Raman spectroscopy (RS), and thermogravimetry-differential thermal analysis (TG-DTA) results show that no graphitization of diamond grain occurs during sintering. The bonding ability between the vitrified bond and diamond grain, along with the microstructure of vitrified-bond diamond composites, was studied using scanning electron microscopy (SEM). Moreover, the results of energy spectrum analysis (EDS) show that the diffusion and segregation of Na at the interface between the diamond particles and the vitrified bond improve the bonding strength, and the vitrified bond can effectively bond with the diamond particles. Finally, the formation mechanism of the honeycomb structure was elucidated using the surface and interface sintering theory. [ABSTRACT FROM AUTHOR]

• Impact response of stiffened sandwich FGPM doubly-curved shell with re-entrant honeycomb auxetic core is studied. • The interaction between the impactor and shell utilizes equivalent spring-mass (SM) model consisting two-degrees-of freedom. • The facesheets are made from FGPM and the shell structure is modeled by first order shear deformation theory. • The impact performance of re-entrant honeycomb auxetic core is compared with regular hexagonal honeycomb core. Owing to unique deformation behavior and high capacity of energy absorption, auxetic structures have garnered significant research attention. To reveal the energy-absorbing properties of the auxetic structure, the impact response of stiffened sandwich functionally graded porous materials (FGPM) doubly-curved shell with re-entrant honeycomb auxetic core is studied by the established analytical model in the present work. The material properties in the thickness direction of FGPM face sheets are adjusted according to the volume fraction of constituents by power law and exponential law, while the core layer is made of the re-entrant honeycomb auxetic core with negative Poisson's ratio. On the basis of the Hertz theory for elastic impacts and the first-order shear deformation theory (FSDT), an analytical model is developed to study its impact phenomenon. Equations of motion are derived using Hamilton's principle, which are further solved analytically using Navier's technique of assuming unknown variables in the double trigonometric series. The time-dependent contact force is obtained by applying the spring-mass (SM) model consisting two-degrees-of freedom. Afterward, the transverse central displacements of the stiffened sandwich FGPM doubly-curved shell are calculated by adopting the Duhamel integration. The impact force and transverse displacements are compared with the previously published results, indicating that the theoretical results agree with the previously published results. Parametric analyses have been carried out to investigate the effect of variation of various parameters such as volume fraction exponents, radii of principal curvatures, porosity volume fraction, core layer inclined angle on the impact response of the sandwich shell. Additionally, the results show that compared with the traditional hexagonal honeycomb core type, the stiffened sandwich FGPM doubly-curved shell with re-entrant honeycomb core type has significant advantages in impact energy absorption. This work may provide an extensive reference and valuable guidance in the impact design and application of auxetic sandwich shell structures. [ABSTRACT FROM AUTHOR]

We used the honeycomb resonator structure and explored its absorptance response in the visible, ultraviolet, to mid-infrared regions. In this solar spectrum range, the average absorption is greater than 90%. In addition, the spectral absorption is 97.69%, 96.35%, 94.45%, and 96.11% in the respective solar spectrum regions, respectively. In this work, we observed the highest absorption response of the solar spectrum. Further, the KNN regressor model is employed for behavior prediction of the proposed absorber structure and results indicate this model highly predicts the absorption values for lower K values. This proposed model due to its ideal characteristics can be employed for a vast range of applications including performance improvement of solar cells, thermophotovoltaics, and many more. [ABSTRACT FROM AUTHOR]

Recrystallized SiC (R–SiC) honeycomb ceramics were prepared using Al 4 SiC 4 as additives through a two–step sintering process, consisting of pre–nitridation treatment at 1800 °C for 180 min, followed by heat treatment for 60 min at temperatures ranging from 2000 to 2200 °C. The influences of firing temperature on phase compositions, microstructures, porosity, and mechanical properties of honeycomb ceramics were evaluated. The results revealed that AlN, SiC, and C were formed in situ after nitriding at 1800 °C. As the subsequent heat treatment temperature increased from 2000 to 2200 °C, the sublimation rate of submicron SiC increased, as well as AlN solid solubility. AlN diffused into SiC lattice and formed the SiC–AlN solid solution, which accelerated the conversion of 6H–SiC to 4H–SiC. According to first–principles calculations, the formation of solid solution contributed to the sintering process, which performed through the reduction of the surface energy of the grains. In addition, the pore size of specimens increased with elevating the heating temperature, and the distribution transitioned from unimodal to bimodal. Simultaneously, AlN and C activated the SiC lattice and facilitated mass transfer rate. The SiC sintering necks were well–developed at 2200 °C, resulting in the optimized overall performance of SiC honeycomb ceramics with a porosity of 52.7% and compressive strength of 17.98 MPa. [ABSTRACT FROM AUTHOR]

Inspired by the double-helix structure of biological DNA, low-volume fraction and high-strength Al 2 O 3 twisted honeycomb structures with characteristics similar to those of helical structures in the z -axis were prepared by digital light processing 3D printing technology. As the twist angle increased, the compressive strength of the fabricated Al 2 O 3 structure decreased, and the deformation mechanism of the Al 2 O 3 structures gradually changed from stretching-dominated to bending-dominated, which can be predicted by the Gibson–Ashby model. The relationship between the effective elastic modulus and the volume fraction that can be modified by varying the wall thickness was described by the Pabst–Gregorova exponential relationship. The compressive strength of the Al 2 O 3 structure with a twist angle of 0° can reach 62.4 MPa at a volume fraction of 13.3%, providing guidance to optimize lightweight structures of ceramics. [ABSTRACT FROM AUTHOR]

Three metal-organic frameworks including Ce-BDC, In-BDC and In/Ce-BDC and corresponding derived CuO/ZnO/In 2 O 3 /CeO 2 catalysts were prepared. The catalyst-loaded cordierite honeycomb ceramic supports were applied in a microreactor for hydrogen production via methanol steam reforming. The In/Ce-BDC-derived catalyst exhibited a methanol conversion rate of 100%, a hydrogen yield of 0.336 mol/h and an energy efficiency of 54% at 300 °C and an inlet methanol flow rate of 0.112 mol/h. Moreover, CO with content lower than 1.5% and catalytic stability of 30 h was recorded. The high specific surface area and superior redox property of the In/Ce-BDC-derived catalyst were characterized. The increased contents of oxygen vacancies and surface oxygen, in collaboration with the improved solid solubility of CuO and ZnO, were associated with the charge exchange induced by the strong interaction between In 2 O 3 and CeO 2 , leading to the excellent catalytic performance of the In/Ce-BDC-derived catalyst. [ABSTRACT FROM AUTHOR]

Na 4 Mn 9 O 18 whiskers were prepared on the wall of cordierite honeycomb ceramics using the molten salt synthesis, and Na 4 Mn 9 O 18 whiskers were grew on channel surface of cordierite honeycomb ceramics to form hierarchical microstructure for catalytic combustion of soot. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to characterize the structural morphology and phase compositions. Na 4 Mn 9 O 18 whiskers with aspect ratio of 24.4 measured by statistics. It was found that the loading rate of the monolithic catalyst reaches 3.588% while the binding rate after sonication almost no change. Whiskers are tightly combined with the cordierite ceramic substrate by the binding strength experiments and EDS analysis. The oxygen temperature-programmed desorption (O 2 -TPD) measurements were performed to investigate the O 2 adsorption property. The catalytic performance of the samples were examined by semi-quantitative thermal gravimetric analysis (TG-DTG) and temperature-programmed oxidation (TPO). The catalyst performance study demonstrates that Na 4 Mn 9 O 18 whiskers decrease the soot combustion temperature apparently. Experiments show the characteristic temperature could be reduced by increasing the catalyst loading. The Na 4 Mn 9 O 18 decreased the ignition temperature of soot particles oxidation, and the cycle stability experiment confirmed that the sample (0h-m-k) has good structural stability and stable catalytic performance. The coarseness of the interface increased because Na 4 Mn 9 O 18 whiskers grew on the cordierite substrate, and the trapping ability improved. Na 4 Mn 9 O 18 is an important type of catalyst which is rarely studied in catalytic oxidation of soot. This catalyst displays good activity and stability in the soot catalytic oxidation. This unique microstructure has potential application in the DPF field. [ABSTRACT FROM AUTHOR]

In this study, PMI foam and aluminum foam are used as reinforcement materials for filling the cells of carbon fiber-reinforced composite square honeycomb sandwiches (CSHSs), forming two new sandwich structures, namely, PMI foam-reinforced CSHS (PRCSHS) and aluminum foam-reinforced CSHS (AFRCSHS). The impact resistance and residual flexural performance of the composites is compared by using low-velocity impact (LVI) and three-point bending (3 PB) experiments. The different impact energy levels of 25 J, 50 J, 65 J, and 100 J are applied. The impact and bending failure process and failure mechanism are analyzed using a combination of industrial computed tomography (ICT) and scanning electron microscopy (SEM). PRCSHS and AFRCSHS are compared for various enhancement effects and their resulting lightweight features. The residual flexural and impact resistance properties of the two sandwiches improved significantly. Compared with CSHS, the maximum impact load of PRCSHS and AFRCSHS increased by 115.6% and 78.9%, respectively. Moreover, the impact energy absorption, residual flexural load, and residual flexural energy absorption increased by 30.9% and 21.3%, 80.7% and 58.5%, and 173.1% and 84.3%, respectively. The PRCSHS was noticeably lightweight, but AFRCSHS was not sufficiently lightweight. The qualitative results of comparison of the two reinforcement materials in this study can be extended to other carbon fiber-reinforced all-composite 2D honeycomb sandwiches. [ABSTRACT FROM AUTHOR]

In this research work, laser powder bed fusion (LPBF) based stainless steel 316L (SS316L) was fabricated and its corrosion behaviour was analysed for the oil-gas piping application. The Field Emission Scanning Electron Microscopy (FESEM) analysis of the LPBF SS316L specimen revealed the presence of 1–2 μ m size honeycomb structure and 2–10 μ m size tabular structures. Nano-size particles in the range of 100 nm–500 nm were formed between the two tabular cells as well as their boundary regions in the LPBF SS316L specimen. The energy-dispersive X-ray spectroscopy (EDS) analysis of the nanoparticle confirmed the presence of Si with a percentage of 1.4% along with 15.9% of Cr and 1.6% of Mo that have the characteristic of dispersion strengthening of the LPBF SS316L specimen. In addition, the δ-ferrite phase was observed in tabular structure boundaries and intercellular regions of solute in the LPBF SS316L specimen. Moreover, among the three crystallographic orientations {001}{101}and {111}, no domination behaviour was observed from the Electron Backscatter Diffraction (EBSD) study. The Transmission Electron Microscopy (TEM) analysis confirmed the presence of nano twin structures that had a span of several nm on the FCC austenite unit cell. These twins came under the {111} category twining that often occurred in FCC metals. A potentiodynamic polarization test was conducted on the LPBF SS316L specimen at five different time periods (i.e., 0, 7, 15, 34 and 56 h) and it was assessed that the 0 and 15 h immersion specimens exhibited superior corrosion resistance compared with other LPBF SS316L specimens. The Nyquist plot revealed that the 0 and 15 h immersion specimens offered the highest resistance value of 1846.1Ω and 1720.3 Ω, respectively against corrosion. The Bode plots of the LPBF SS316L specimen followed a similar trend as the Nyquist plots. [ABSTRACT FROM AUTHOR]

• The nonlocal effects are accounted for when evaluate the equivalent modulus of micro/nano-honeycombs. • For regular hexagonal honeycombs, the smaller the length, the more significant the nonlocal effects. • The present method has a good universality, which is applicable to both macro and micro/nano scale honeycombs. When the structural size of honeycomb enters micro/nano scale, the influence of nonlocal effects on the mechanical responses becomes non-negligible, which should be taken into account when evaluate the mechanical properties of micro/nano-honeycombs. To this end, a novel method for predicting the equivalent elastic moduli of micro/nano-honeycombs is proposed. In this method, the two-phase local/nonlocal model is introduced into the constitutive equations and the analytical solution of the equivalent moduli is derived according to the energy equivalent principle. It is illustrated by the numerical examples that the results of the present method are lower than those of the classical elasticity theory, which is consistent with the phenomena observed in the experiment, effectively showing the nonlocal effects. The magnitude of nonlocal effects can be influenced by the geometrical size of the honeycomb. The smaller the geometric size of the honeycomb is, the more significant the nonlocal effects are. With the increase of the geometrical size of honeycomb, the nonlocal effects gradually weaken, and the numerical values predicted by the present method gradually approach the equivalent moduli values of the macro-scale honeycombs. Hence the present method has a good universality that can be used in both macro and micro/nano scale honeycombs. [ABSTRACT FROM AUTHOR]

We explore the quantum-memory assisted entropic uncertainty (QMA-EU), Jensen-Shannon coherence and entanglement dynamics in a Graphene sheet of disordered electrons in the presence of the intrinsic decoherence. The Graphene sheet containing two sublattices in a two-dimensional honeycomb lattice, which results due to the impurity-potentials interaction of two Dirac points. Entropic uncertainty and logarithmic negativity are used to investigate the generation and preservation of QMA-EU and entanglement under the major factors of Graphene material, including the band structure parameter, the wave numbers as well as the decoherence effect. For the initial uncorrelated two-lattice-point-qubit state, it is found that the lattice-point interactions have high capacity to generated partially/maximally two-lattice-point-qubit entangled and hence the partial/perfect Bob's ability to guessing the outcome of Alice's measurement. The increase of the graphite band structure parameter, the wave numbers enhance the generated lattice-point entanglement and Jensen-Shannon coherence, and hence the quantum memory game has a high prediction accuracy. For the intrinsic decoherence, the ability to generate entanglement, Jensen-Shannon coherence. and guessing the Alice's measurement outcomes weakens. The sudden death-birth phenomenon in the logarithmic-negativity dynamics appears. The increase of the graphite band structure parameter weakens the robustness dynamics against the decoherence effect, while the increase of the wave number operators enhances this robustness. For initial maximally correlated state, the robustness dynamics of the QMA-EU, Jensen-Shannon coherence, and logarithmic-negativity entanglement is very sensitive to the increase of the band structure, wave numbers, and intrinsic decoherence. [ABSTRACT FROM AUTHOR]

Microwave absorbing (MA) materials with yolk-shell structures have been extensively studied in impedance matching. However, the impedance matching achieved by the complementary effect of the core and the shell does not determine the reflection of the microwaves upon the occurrence at the first incidence. The interaction between the outer layer of materials and the electromagnetic waves significantly impacts the MA properties of materials. In this study, the impedance matching improvement method of the shell structure was further explored by preparing CoFe 2 O 4 @HCN (honeycomb carbon with N-doping) through the hydrothermal method followed by hydrolysis, polymerization, etching, and annealing. The resulting structure with heteroatoms doping provided the novel CoFe 2 O 4 @HCN with excellent impedance matching and multiple loss mechanisms contributing to MA process. The absorber with a filler loading of 40% exhibited an RL min of −68.03 dB with a matching thickness of 2.5 mm. The efficient absorbing bandwidth reached 5.92 GHz (a change from 11.92 to 17.84 GHz) at 1.99 mm thickness. Interestingly, these findings look promising for future synthesis and application of yolk-shell structure microwave absorbers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical architected materials achieve enhanced mechanical properties. • A deep learning approach based on an attention-based diffusion model is capable of providing both, forward and inverse predictions. • We discover hierarchical microstructure candidates for a specified nonlinear mechanical response. • We demonstrate single-shot end-to-end performance in both forward/inverse directions across the entire deformation regime. • Biologically inspired materials design for high-throughput discovery specifically for diverse nonlinear constitutive relationships is provided. Inspired by natural materials, hierarchical architected materials can achieve enhanced properties including achieving tailored mechanical responses. However, the design space for such materials is often exceedingly large, and both predicting mechanical properties of complex hierarchically organized materials and designing such materials for specific target properties can be extremely difficult. In this paper we report a deep learning approach using an attention-based diffusion model, capable of providing both, forward predictions of nonlinear mechanical properties as a function of the hierarchical material structure as well as solving inverse design problems in order to discover hierarchical microstructure candidates for a specified nonlinear mechanical response. We exemplify the method for a system of compressively loaded four-hierarchy level materials derived from a family of honeycomb structures, where patterns of distributed buckling events are unitary deformation events that control small- and large-scale deformation behavior. Our model offers exquisite single-shot end-to-end performance in both forward and inverse directions across the entire range of deformation regime, and is capable of rapidly discovering multiple solutions that satisfy a design objective in accordance with the known physical behavior elucidated by, and validated with, coarse-grained simulations. The model provides an effective way towards biologically inspired materials design for high-throughput discovery in order to achieve diverse nonlinear constitutive relationships. [ABSTRACT FROM AUTHOR]

• A novel composite auxetic sandwich plate was fabricated. • Modal experiments were conducted to research the free vibration behaviours. • Moduli of composite reentrant honeycomb core were deduced. • Effects of relative density and dimensions on natural frequencies were studied. The free vibration behaviours of carbon fiber composite sandwich plates with reentrant honeycomb cores were explored by experiment, theory and finite element method (FEM) in present study. The composite sandwich plates with reentrant honeycomb cores were designed and fabricated through hot-press and secondary forming technology. The modal characteristics of composite auxetic honeycomb sandwich plates were tested under simply supported boundary conditions. Furthermore, the influences of relative densities and dimensions on the natural frequencies of composite auxetic honeycomb sandwich plates were studied. The equivalent moduli of the unit cell of reentrant hexagonal core were deduced. The free vibration control equation was derived to gain the natural frequencies of the sandwich plates by Zig-Zag theory. The theoretical results of the natural frequencies were obtained and compared with the experimental results and finite element calculation results. The results showed that the theory and FEM could estimate the natural frequencies of this kind of sandwich plates accurately. The natural frequencies of the sandwich plates raised as the increasing of relative densities and influenced by dimensions of the core. [ABSTRACT FROM AUTHOR]

A nanometric Rh overlayer exhibits excellent three-way catalytic activity under stoichiometric conditions. However, dynamic changes in the air-to-fuel (A/F) ratio under experimental conditions deteriorates the catalytic activity caused by the lack of oxygen storage/release capability of Rh. In this study, we first report that the surface modification of the Rh overlayer by a small amount of Ce using a sequential metal deposition technique based on the pulsed arc-plasma method enhances its three-way catalytic activity under A/F perturbation conditions. X-ray photoelectron spectroscopy and X-ray absorption fine structure measurements revealed that the redox behavior of the surface Ce contributed to an oxygen storage/release and buffered the A/F change. The Ce-modified Rh overlayer with a metal honeycomb structure exhibited high activity for the three-way catalytic reaction even under A/F perturbation conditions at high space velocity. This novel catalytic converter is expected to be significantly process and energy saving compared to the conventional catalytic converter. Thus, the oxygen storage/release performance, heat resistance, and low-temperature activity can be improved by controlling the surface composition. [Display omitted] • Sequential metal deposition technique based on pulsed arc-plasma method. • Surface of the Rh overlayer was modified by a small amount of Ce. • Redox behavior of the Ce contributed to an oxygen storage/release. • Ce-modified Rh overlayer exhibited high activity for three-way catalytic reaction. [ABSTRACT FROM AUTHOR]

The highest incidence of death in systemic sclerosis due to pulmonary disease raises the need for early detection and treatment. The study aim is the assessment of interstitial pulmonary disease by Multi Detector High Resolution CT (MDCT) and finds its relationship with the other disease parameters and the Pulmonary Function tests (PFT). A prospective cross-sectional study was performed in Assiut University Hospitals from May 2018 to January 2020 and included 62 consecutive SSc female patients. Demographic, clinical, Laboratory, PFT and MDCT assessment were conducted for all participants. The coarseness of fibrosis was 8.32 (range 0.0–17), the average proportion of ground-glass opacification was 28.3% (range, 0.0%–75%). Honey-comb pattern was seen in (52.5%). Mean Extent of disease was 46.25 ± 3.7 (range 5–81). Restrictive deficit found in 42 patients. Significant relation was found between the extent of disease and the percentage predicted FVC (r = 0.373, p 0.018) and FEV1/FVC (r = 0.593, p 0.000) and coarseness of fibrosis and proportion of ground glass opacification correlated inversely with VC (r = −0.385, p = 0.014, r = −0.376, p = 0.017 respectively), Rayanud's phenomena, modified Rodnan Skin Score and Medsger's general are positively correlated with MDCT disease extent. Scoring of systemic sclerosis (SSc) related interstitial lung disease (SSc-ILD) could be applicable as one of the important tools for disease assessment. [ABSTRACT FROM AUTHOR]

Aluminum honeycomb is newly introduced in the tether-net launcher device to attenuate the large recoil force and impact generated on the platform. The stress–strain of aluminum honeycomb is first obtained through the quasi-static compression experiment to study the mechanical properties. The compression simulation model is then established using the crushable foam plasticity model. By comparing the simulation and experiment results, the error of plateau stage force is 0.33%, which validates the accuracy of the simulation model. After that, the internal ballistic responses of the launcher are gained by the equivalent classical interior ballistic equations. The dynamic launch model is built through the integration of the above models. It is verified by the dynamic launch experiment, with the average recoil error being 5.9%. Finally, the recoil performance of the launcher with or without aluminum honeycomb buffer is studied. The results show that aluminum honeycomb can reduce the average launch recoil force by 17.23%, with little effect on launch velocity, demonstrating good energy absorption ability. [ABSTRACT FROM AUTHOR]

Structural formations of metal-organic frameworks (MOFs) are predominately composed of empty space pockets inside a honeycomb structure assembled of organic linkers and metal ions, with the exception of a few small pockets of filled spaces. However, these extraordinary filled pockets provide a valuable resource as its applications when it comes through in various active areas. Recently, taking advantage of the rare combination of porosity, high surface area, and charge conductivity incorporated in MOFs applications such as electronic sensors, charge storage devices, electrocatalysts, and others previously outside the scope, but now has been developed. This review envisioned a scenario by presenting a piece of individual and collective established studies and investigations during the last few years for carbon dioxide reduction (CO 2 R) as MOF-based composites adjacent with semiconductor, photosensitizer, and conductive photo-electrocatalysts are discussed. Various strategies have been discussed to improve photo-electrocatalysts' performance by synthesis, bandgap engineering, and mobilizing the catalyst surface for optimizing yield. Moreover, the reaction mechanisms to drive the MOF, operational, improve stability, and evaluation approaches are summarized. To end with a discussion, actual limitations, future perspectives, and concerns are addressed in this review. [ABSTRACT FROM AUTHOR]

[Display omitted] • We fabricated carbonate apatite honeycomb scaffolds with vertical uniaxial channels. • At 4 weeks post implantation, all honeycomb scaffolds augmented new bone. • The augmentation happened close to the top surface of the scaffold. • In the following 8 weeks, the height and amount of new bone increased. • HC300 resisted compression from fasciae at 12-weeks post implantation. • Honeycomb structure is inherently suitable for vertical bone augmentation. Cases of intractable dental implant require vertical bone augmentation; however, the predicted bone height and volume are difficult to obtain. In vertical bone augmentation, the contact surface between the scaffold and the bone is limited to the bottom face of the scaffold. Furthermore, the strength decrease caused by scaffold resorption leads to collapse of the augmented site, leading to a decrease in the bone volume and height. To promote bone ingrowth, we fabricated carbonate apatite (i.e., bone mineral) honeycomb (HC) scaffolds with uniaxial channels vertically penetrating the scaffold. Furthermore, we controlled the scaffold resorption rate, eventually the endurability for compression, and the bone height and volume by controlling the strut thickness. The channel aperture was controlled to be 230–260 μm to promote bone ingrowth. Furthermore, the strut thicknesses of the HC scaffolds were adjusted to 100, 200, and 300 μm to control the scaffold resorption; these scaffolds were designated as HC100, HC200, and HC300, respectively. At 4 weeks post-implantation on rabbit calvarium, all scaffolds had already vertically augmented new bone close to the top surface of the scaffold. In the following 8 weeks, the height and amount of new bone in all scaffolds increased. Notably, HC300 was resorbed synchronously with new bone formation, allowing it to endure the compression from the fasciae for 12 weeks post-implantation. Furthermore, HC300 formed larger-diameter blood vessels than those of HC100 and HC200. The HC scaffolds surpassed the various combined scaffolds and growth factors or stem cells in the ability for vertical bone augmentation. Thus, the HC structure is inherently suitable for vertical bone augmentation. Notably, the HC scaffolds with 300-μm-thick struts enhanced both new bone formation and angiogenesis. This study revealed a structurally suitable design for achieving an outstanding outcome in vertical bone augmentation. [ABSTRACT FROM AUTHOR]

A novel network interlacing ZrC-VC ceramic coating was prepared by a pioneering spillover permeation. With the increase of Zr content in the blind vias, the content of ZrC in the coating and the density of the coating all decrease. The density of the coating on C/C–ZrC–SiC substrate is obviously higher than that on C/C substrate. The linear ablation rate of the novel ceramic coated C/C–ZrC–SiC composites was −0.06 μm/s with about 20 and 1.56 times reduction than C/C composites and C/C–ZrC–SiC composites respectively. The improved ablation resistance was attributed to a dense honeycomb ZrO 2 layer filled with liquid vanadium oxide in the ablation center and the improved thermal radiation. [ABSTRACT FROM AUTHOR]

Although honeycomb is a kind of lightweight structural material with great potential, its specific strength is not always able to meet the requirements, especially in the weight-sensitive field. Inspired by the bionic idea of cuttlebone, the curved-wall configuration design is proposed to strengthen the buckling impedance of honeycomb, which can effectively prevent the premature occurrence of buckling failure mode induced by thin walls. Compared with the straight-wall honeycomb materials of the same geometric size, the probability of buckling failure in curved-wall honeycomb materials proposed in this paper is reduced by more than 22 %. Moreover, to achieve the preparation of curved-wall configuration, a processing strategy that uses stretching process to prepare ultralight carbon fiber honeycomb (Carbcomb) material is firstly introduced. Compared to the Hexcel Corporation's aluminum honeycomb with a density of 21 kg/m3, for the Carbcomb, the specific compressive strength and specific shear strength along both the L and W directions respectively improved by 57 %, 61 % and 77 %. In addition, the minimum density of fabricated Carbcomb (14.6 kg/m3) is less than that of the Hexcel's products (16 kg/m3), and the research findings fill the gap of the carbon fiber honeycomb material in low density areas (10 ∼ 30 kg/m3). More importantly, this process which does not require much manual operation can effectively avoid the problems of unstable mechanical properties, difficult mass production and high preparation cost of the existing carbon fiber structural parts. This curved-wall configuration design and fabricated approach widens the potential of carbon fiber honeycomb as a structural material, and makes it possible for lower cost and higher efficiency in aerospace and transportation applications. [ABSTRACT FROM AUTHOR]

Real-time thermal deformation monitoring plays a crucial role in calibrating phase signals and maintaining satellite performance for large spaceborne antennas. The inverse finite element method (iFEM) represents a promising shape-sensing methodology applicable to monitor the three-dimensional displacement of structures through surface-measured strain. However, the high-accuracy reconstruction of large-scale structures involves a large number of inverse elements, which leads to the low level of computational efficiency. To address this issue, a displacement-gradient-based variable-size iFEM is proposed in this paper. According to the characteristics of deformation, this method optimizes the size of each inverse element to reduce the number of inverse elements required, which improves real-time performance and maintains the high accuracy of reconstruction. The real-time performance of the proposed method is verified by conducting a simulation test on a large-scale honeycomb antenna. According to the simulation results, the variable-size iFEM is applicable to achieve the same accuracy of reconstruction using fewer inverse elements than conventional iFEM. An experimental test is performed and the optimal variable-size discretization that balances accuracy and efficiency is determined. The results show that the maximum error of reconstructed displacement is less than 7.3 % and the reconstruction time is in no excess of 0.1 s. [ABSTRACT FROM AUTHOR]

Tandem design is promising to improve the undesired compressive behavior of honeycomb for the long-stroke demand. Therefore, a novel tandem honeycomb, named tandem face-centered hierarchical honeycomb (TFCHH), is developed to achieve the perfect load-bearing process. The deformation mechanism of TFCHH is revealed by the compressive experiments, which dissipates energy by progressive folding and demonstrates a multi-stage plateau response. The numerical research is conducted to explore the compressive properties of TFCHH. It is observed that the energy absorption and load-bearing stability of TFCHH is 23.04 % and 38.24 % higher than those of integrated face-centered hierarchical honeycomb. To approach the perfect load-bearing behavior of TFCHH, the matching strategy of hierarchy order and relative density is investigated to fully exploit the compressive potential of hierarchical honeycomb components. As a result, the optimal load-bearing capacities of hierarchical honeycomb components with the hierarchy order from 1 to 3 are obtained when the relative densities are 16.6 %, 15.0 %, and 11.2 %. The customized design on the load-bearing behavior of TFCHH demonstrates that altering the stacking sequence can control the deformation sequence of hierarchical honeycomb components, and adjusting the composition proportion can tailor the effective stroke of the desired plateau stress. By establishing the theoretical relationship between the plateau force and configuration parameters, it is found that the load-bearing behavior of TFCHH is accurately predicted with the dynamic correction coefficient of 1.4. [Display omitted] • A face-centered hierarchical strategy is proposed to develop a novel tandem honeycomb. • The perfect load-bearing behavior is approached by the matching design of hierarchy order and relative density. • Multi-stage load-bearing behavior is customized by controlling the stacking sequence and composition proportion. • Theoretical relationship between multi-platform forces and structural parameters is established accurately. [ABSTRACT FROM AUTHOR]

• Hierarchical honeycomb panel absorbed 9.6% more energy, needing 4.8% more for perforation than AuxHex sandwich panel. • Front sheet failed through ductile shearing; core crushed, back sheet plugs detached after impact. • Back sheet deflection 12–15% higher, indicating longer contact and force disparity during impact. Honeycomb sandwich panels (HSPs) are extensively employed across various industries owing to their outstanding strength and capacity for energy absorption. Despite their widespread use, the potential of additively manufactured (AM) honeycombs in ballistic protection remains relatively unexplored. This study aims to comprehensively assess the energy absorption performance of two distinct HSP configurations, namely AuxHex and Hierarchical, through high-velocity impact tests spanning velocities ranging from 220 to 270 m/s. The high-velocity impact experiments are conducted using a single-stage pneumatic gun, complemented by simulations executed via Abaqus/Explicit. Our findings reveal that the hierarchical HSP demonstrated a notable 9.6 % enhancement in energy absorption compared to panels featuring an AuxHex honeycomb. Interestingly, the hierarchical panels also necessitated 4.8 % more energy for perforation. In terms of failure mechanisms, both sheets of the HSPs experienced ductile shearing, with the formation of characteristic petal-like structures. Concurrently, the honeycomb core underwent fragmentation on the side facing the projectile, while plugs were ejected from the back sheet. Moreover, our analysis indicates that the residual deflection of the back sheet surpassed that of the striking sheet by 15–20 %. This disparity can be attributed to prolonged contact duration and variations in interaction forces between the sheets. Overall, this investigation provides valuable insights into the energy absorption capabilities of AM honeycomb-based HSPs under high-velocity impact conditions, shedding light on their potential for enhanced ballistic protection in various applications. [ABSTRACT FROM AUTHOR]

• Bubble behavior and fluid distribution were studied in a honeycomb microreactor. • The complete breakup of bubbles benefits the fluid distribution uniformity. • The growth rate of pressure drop increases with U G due to the local pressure drop. • A new pressure drop correlation of honeycomb microreactor was developed. The bubble breakup dynamics and fluid distribution in a honeycomb microreactor with chemical reaction were visually investigated. The bubble split and collide behavior in multistage divergent-convergent branching structures were observed and studied. It was demonstrated that the bubble breakup at bifurcations relies dramatically on the collision behavior of the bubble pairs at the downstream convergence. Four bubble flow regimes were observed at the convergence: no collision, collision-slipping, squeezing-slipping, and blockage-slipping. The non-uniformity of the fluid distribution mainly stems from uneven breakup of bubbles at the upstream bifurcation, the lack of bubble breakup, the feedback effects of downstream and the manufacturing errors. Furthermore, the variation of pressure drop in a honeycomb microreactor was explored. The overall pressure drop was found to increase by the local pressure drop, whereas reduced with the increased absorption capacity of liquid phase. Taking these impact factors into account, a modified Lockhart-Martinelli pressure drop model was developed. [ABSTRACT FROM AUTHOR]

[Display omitted] • In situ FZC honeycomb spheres for cellulase direct adsorption and immobilization. • ZIF-8 components of the carrier regulate secondary structure of cellulase. • Thermal activation of immobilized enzyme was reported. • Application of immobilized cellulase in biomass saccharification. This paper presents a promising heterogeneous biocatalyst-immobilized cellulase system, which can facilitate the targeted catalytic conversion of biomass to reducing sugars. Magnetic Zeolite Imidazole Framework-8/chitosan (Fe 3 O 4 /ZIF-8/CS, FZC) hybrid honeycomb microspheres were synthesized to immobilize cellulase using an in-situ growth strategy. The enhancement of immobilization efficiency induced by each constituent of the composite carrier was explored. This exploration was grounded in varying combinations of components within the honeycomb composite spheres, revealing the indispensability of ZIF-8. Through in-situ assembly, the composite material presents a microsphere with an internal honeycomb structure and multilevel pores. Effective immobilization, temperature-responsive conformational change, and cyclic stability were achieved due to the scaling effect of the channel, extensive specific surface area, and abundant amino group interactions enable immobilized enzymes to maintain excellent performance under challenging operating conditions, demonstrating an enhanced structure-performance relationship. With the obtained immobilized cellulase, we achieved a high load (461.67 mg/g) of cellulase and a significant reducing sugar yield (328.39 mg/g) from corncob waste. In addition, we investigated the enhancement effect of thermal activation on the immobilized enzyme activity of composite carrier. The results showed that the appropriate heat treatment was conducive to the activation of FZC immobilized enzyme with a reducing sugar yield 1.61 times higher than that of the control. The strategy provided in this study promotes the development of immobilized biocatalysts and provides a useful reference for the further design of biocatalytic systems. [ABSTRACT FROM AUTHOR]

• A novel composite auxetic reentrant honeycomb structure is designed and fabricated. • The one-stage light gas gun and diffuser-type shock tube were utilized to generate and propagate exponential decaying shock wave. • The effect of gradient form on impact resistance performance was experimentally and numerically investigated. • The effect of relative density of composite reentrant honeycomb structure was analyzed and investigated. The researches on dynamic responses of underwater impulsive loading have been conducted. However, the previous study mainly concentrated on metal sandwich structure and fixed supported boundary. The relative research on composite auxetic re-entrant honeycomb structure and simply supported boundary are rarely. In this paper, the effect of the gradient form and relative density on impact resistance performance of composite auxetic re-entrant honeycomb structure was experimentally and numerically investigated. The one-stage light gas gun was applied to provide initial kinetic energy of the fly plate, and the diffuser-type shock tube was utilized to generate and propagate exponential decaying shock wave. The pressure–time curve was respectively amplified and recorded by the charge amplifier and oscilloscope. The response speed, final deflection of rear panel and failure mode of cores and panels were used to evaluate impact resistance of composite auxetic re-entrant honeycomb structures. Moreover, acoustic-structure interaction algorithm was applied to simulate impact course of specimens in Abaqus/Explicit. The results between experiment and numerical simulation exhibited good consistency. The results indicated that the positive gradient form could excessively slow down response speed of rear panel by dissipating energy of shock wave, and the average gradient demonstrated smaller final displacement of rear panel and less failure compared with graded structures. [ABSTRACT FROM AUTHOR]

[Display omitted] • A GKNS with re-entrant cells has an ultimate elastic strain (UES) > 70 %. • UES of the GKNS depends slightly on temperature. • UES of the GKNS becomes lower when having a transversal periodic boundary. • UES is tunable by adjusting the layout and the size of cells in a GKNS. The programmable nature of graphene kirigami enables it highly applicable in the development of stretchable nanodevices. In this study, we employed molecular dynamics simulations to investigate the large deformation behavior of a structured graphene kirigami nano-spring (GKNS) with re-entrant honeycombs. During a uniaxial test, the elastic deformation can be categorized into two stages based on the applied load level. Stage I exhibits a maximal strain (ε Ystart) exceeding 50 % under low loading conditions, while stage II demonstrates a strain (ε Yend) surpassing 70 % at a high hardening rate. Both ε Ystart and ε Yend are greater than those observed in GKNS with transversal periodic boundary conditions. Furthermore, increasing the length or decreasing the width of bars within GKNS with cells of identical shape leads to an increase in both ε Ystart and ε Yend values. Ambient temperature has minimal impact on ε Ystart and ε Yend however, higher temperatures result in lower hardening rates due to weakened carbon–carbon bonds within GKNS structures. Additionally, variations in cell/void arrangement within structured GKNS affect both ε Ystart and ε Yend values, whereas widening the GKNS structure leads to reduced hardening rates. The findings presented herein provide valuable insights for designing nanodevices that necessitate significant deformations. [ABSTRACT FROM AUTHOR]

Aluminium honeycombs serve as a primary core material for energy absorption in various transportation and structural applications, with particular emphasis on their superior strength in the out-of-plane direction. However, conventional fabrication methods rely on adhesive bonding of aluminium strips, revealing poor bond strength under collapse stress. Premature structural failure arises from adhesive failure and subsequent debonding of cell walls, occurring before the aluminium strips fail. Addressing this, an innovative approach utilizing friction stir seam, and spot welding has been introduced to overcome adhesive bonding limitations. Welded joints exhibit a remarkable tenfold increase in strength compared to adhesive bonds. Notably, welded honeycombs demonstrate 32–37% higher crushing strength and an 80–84% increase in specific energy absorption capacity over adhesive-bonded variants. Collapse mechanisms involve pure buckling in seam-welded honeycombs without weld region failure, while spot-welded honeycombs display a combination of bending-shear and spot tearing, particularly evident with wider weld spacing. Obtaining longitudinal loading on seam-welded honeycomb walls is advantageous because of its 57% higher normalized maximum load capacity compared to the shear-tensile strength obtained for spot-welded walls. This study marks a significant advancement in the existing manufacturing route for honeycombs in achieving superior crushing performance. [Display omitted] • Adhesive-bonded honeycombs exhibited adhesive failure and debonding during crushing. • Novel fabrication methods for aluminium honeycomb using friction stir (FS) seam and spot welding are presented. • Lap-shear failure mechanism varied in spot welds with different plunge depth. • FS welded honeycombs demonstrated 80–84% superior crushing performance. • Higher pitch in FS spot-welded honeycomb caused tearing due to asymmetric folding. [ABSTRACT FROM AUTHOR]

Designing absorbers with structural support to achieve ultra-wideband and wide-angle absorption properties is crucial for addressing the growing concern of electromagnetic pollution. In this study, a strategy is proposed to further broaden the bandwidth of structural absorbers by applying different materials to different structures and then nesting these different structures. Six composite materials were prepared using Ni and rGO as absorbers, and a dual honeycomb nested structure was fabricated using 3D printing technology. The minimum reflection loss (RL) of the two types of composite materials was −19.3 dB and −15.8 dB, respectively, with effective absorption bandwidths (EAB) of 4.6 GHz and 4.4 GHz, demonstrating mechanical compatibility and electromagnetic substitutability. The dual honeycomb nested structure utilized a multiscale design approach, achieving broadband absorption up to 14.27 GHz and compressive strength of 5.92 MPa. Furthermore, stable frequency response of transverse electric (TE) waves was observed within an incident angle range of 0°–40°, while absorption frequencies exceeded 12 GHz as transverse magnetic (TM) waves incident angle varied from 0° to 60°, highlighting wide-angle absorption characteristics. The dual composite preparation strategy of materials and structures for absorber fabrication provides a new perspective for further expanding the bandwidth of absorbers. [ABSTRACT FROM AUTHOR]

• The models for thermal conductivity tensor of two types honeycombs are proposed. • Impact of the wall uniformity within honeycomb on the thermal property is quantified. • Honeycomb ETC's max anisotropic porosity reduces as thermal conductivity ratio rises. The effective thermal conductivity (ETC) is a critical parameter for simulating macroscopic heat transfer processes in composite materials, which estimation is particularly critical where the thermal conductivity of the composite phases is completely different. The huge difference in thermal conductivity of the composite phases makes their volume fraction modulation a classical way to reach the desired thermal conductivity. Nevertheless, the typical manufacturing process of honeycomb cellular structures allows various degrees of stretching of the structure, leading to various honeycomb geometries. In these 'real' structures some of the honeycomb wall sides are twice as thick as other parts, modifying the symmetry of the system with respect to honeycomb with uniform wall side thickness. A noticeable example of these composites is that of a hexagonal metallic honeycomb structure filled with phase change material (PCM) which is a widely utilized material in the field of thermal storage and thermal management by exploiting the heat absorbed/released by the PCM phase during its melting/solidification. While the thermal response of a PCM composite during a thermal cycle is not only defined by thermal conductivity (but also by cell size), this represents the basis for the with the optimization of a system based on a composite PCM. For this reason, in this study, steady-state simulations of heat transfer in unit honeycomb cells in different directions perpendicular to the cell axis are conducted to quantify the impact of morphology on the thermal property of the different wall types within honeycomb structures. The results demonstrate that in both SHS and DHS, the porosity exhibiting maximum anisotropy of ETC decreases as the thermal conductivity ratio increases. Moreover, simple predictive models for calculating the ETC in all directions are proposed for each type of honeycomb, considering a wide range of porosity and thermal conductivity ratio, with a relative error limited to 2 %. [Display omitted] [ABSTRACT FROM AUTHOR]

While sodium hypochlorite (NaClO) has long been used to disinfect drinking water, concerns have risen over its use due to causing potentially hazardous byproducts. Catalytic ozonation with metal-free catalysts has attracted increasing attention to eliminate the risk of secondary pollution of byproducts in water treatment. Here, we compared the disinfection efficiency and microbial community of catalytic ozone with a type of metal-free catalyst fluorinated ceramic honeycomb (FCH) and NaClO disinfectants under laboratory- and pilot-scale conditions. Under laboratory conditions, the disinfection rate of catalytic ozonation was 3∼6-fold that of ozone when the concentration of Escherichia coli was 1 × 106 CFU/ml, and all E. coli were killed within 15 s. However, 0.65 mg/L NaClO retained E. coli after 30 min using the traditional culturable approach. The microorganism inactivation results of raw reservoir water disinfected by catalytic ozonation and ozonation within 15 s were incomparable based on the cultural method. In pilot-scale testing, catalytic ozonation inactivated all environmental bacteria within 4 min, while 0.65 mg/L NaClO could not achieve this success. Both catalytic ozonation and NaClO-disinfected methods significantly reduced the number of microorganisms but did not change the relative abundances of different species, i.e., bacteria, viruses, eukaryotes, and archaea, based on metagenomic analyses. The abundance of virulence factors (VFs) and antimicrobial resistance genes (ARGs) was detected few in catalytic ozonation, as determined by metagenomic sequencing. Some VFs or ARGs, such as virulence gene ' FAS-II ' which was hosted by Mycobacterium_tuberculosis , were detected solely by the NaClO-disinfected method. The enriched genes and pathways of cataO 3 -disinfected methods exhibited an opposite trend, especially in human disease, compared with NaClO disinfection. These results indicated that the disinfection effect of catalytic ozone is superior to NaClO, this finding contributed to the large-scale application of catalytic ozonation with FCH in practical water treatment. [Display omitted] • Catalytic O 3 by FCH improves disinfection ratio of E. coli over O 3 about 3∼6-fold. • Catalytic O 3 kills more organisms and unchanges the relative abundance of species. • Catalytic O 3 and NaClO exhibit different effects on the number of VFs and ARGs. • Catalytic O 3 can especially eliminate Mycobacterium_tuberculosis with VF FAS-II. • Catalytic O 3 rather than NaClO can completely eradicate genes of human diseases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bioinspired design was used to ceramic materials via DIW technique. • Polysilazane (PSZ) based ceramic materials were printed by DIW 3D printing. • B 4 C-based honeycomb ceramic 3D structures were printed by PSZ/B 4 C ink. • B 4 C-based honeycomb ceramic was impregnated by epoxy resin for armor structures. B 4 C ceramic holds enormous application potential in the lightweight armors. In order to simplify the design of armor materials, 3D printed B 4 C-based honeycomb ceramic via DIW technique with high solid content were fabricated using printing ink with B 4 C powder, BYK-2070 dispersant, BAC solvent, PSZ adhesive and DCP cross-linking agent. The role of each constituent and the printing parameters of such honeycomb ceramic were investigated. In addition, epoxy resin was employed to impregnate PSZ-modified B 4 C-based honeycomb ceramic to prepare three-dimensional structure hybrid composites with excellent mechanical strength (172 MPa of flexural strength, 4.95 KJ/m2 of impact strength) and physiochemical properties (7.52 % of open porosity, 5.5 % of water absorption, 1.35 g/cm−1 of density, and 5.2 GPa of hardness). The exceptional performances of the three-dimensional structure hybrid composite come from the bioinspired structure design, new chemical bonds (such as the formation of B–C, C–N and Si–B bonds) formed in the ceramic material and cross-linking reaction occurred during curing between epoxy resin and PSZ. The findings in this study provide an effective strategy for the fabrication of B 4 C-based composites with controllable structures and mechanical performances and exhibit the potential application in complex armor structures. [ABSTRACT FROM AUTHOR]

High temperatures can significantly diminish the efficiency of solar photovoltaic panels, emphasizing the critical need for effective thermal management strategies. While the use of phase change material has shown promise in this regard, issues arise from non-uniform temperature distribution within the phase change material, limiting its overall effectiveness. This paper introduces an innovative solution by incorporating a novel honeycomb-like aluminum structure into the phase change material tank, aiming to address these challenges. Numerical investigations explore various configurations involving different phase change material volumes and aluminum honeycomb grid thicknesses. The honeycomb structure proves effective in preventing the formation of a single high-temperature melting pool, ensuring a more uniform distribution of melting zones throughout the phase change material. Compared to scenarios without the honeycomb structure, the proposed design achieves an additional 10 °C reduction in photovoltaic cell temperature, translating to a noteworthy 0.57% improvement in panel efficiency. This enhancement is particularly significant given the baseline low efficiency of the photovoltaic panel, which stands at 14.7%. Furthermore, the study reveals that increasing the thickness of the aluminum grid contributes to enhanced temperature uniformity, reducing the maximum temperature by up to 4 °C. The findings underscore the potential of the proposed honeycomb structure. • A novel aluminum honeycomb structure is proposed for photovoltaic panel thermal management. • Compared to panels cooled without the honeycomb, it achieves a 10 °C temperature reduction. • The structure enhances photovoltaic panel efficiency by 0.57%. • Uniform temperature distribution and melting zones are achieved in the phase change material zone. • Improved thermal management enhances efficiency, prolongs panel lifespan, and ensures system reliability. [ABSTRACT FROM AUTHOR]

Honeycomb structures are commonly adopted due to their superior energy absorption capacity. In this study, a new bionic glass sponge–type honeycomb structure (BSH) with a quadrilateral octagonal mesh microstructure inspired by the sea sponge structure was proposed. The in-plane crushing performance of the BSH with different geometrical parameters under different crushing speeds was investigated by ABAQUS/Explicit. The numerical findings suggested that the BSH displayed stronger energy absorption in contrast to the square, hexagonal and hierarchical honeycombs at both quasi-static and dynamic crushing conditions. More plastic hinges and more unit walls involved in deformation resulted in a high energy absorption capacity. In addition, three typical deformation modes of the BSH under different loading speeds were discussed, and the empirical model to predict the plateau stress of the BSH was established based on the shock wave theory. Finally, the effect of boundary segmentation parameter m on crushing performance was also illustrated. The energy absorption capacity reaches a maximum at m = 3 for quasi–static loading, whereas at m = 5 for dynamic loading. These findings provide valuable insights into the optimization of bionic honeycombs. [ABSTRACT FROM AUTHOR]

In this study, the nonlinear vibration behaviours of foam-filled honeycomb sandwich cylindrical shells (FHSCSs) are investigated theoretically and experimentally. Initially, a time-domain minimum residual (TDMR) method is first adopted for the analysis of nonlinear free and forced vibrations of the FHSCSs, which is based on a dynamical model developed, with the effective material parameters of the foam-filled honeycomb core being obtained by employing the Gibson method and the Hamilton equivalence technique. Based on the high-order shear deformation shell principle and von Karman's theory, the nonlinear natural frequencies and resonant responses are solved using the Broyden iterative approach and TDMR method. Furthermore, several literature results are utilized for the rough verification of such a method. Meanwhile, the FHSCS specimens are made manually and comprehensive tests with various base excitation energies are undertaken to provide a thorough validation of the current method. It can be found that the largest calculation errors of natural frequencies and resonant responses are 4.9 and 12.3%, respectively. Finally, the influences of the core form and base excitation amplitudes on the nonlinear vibration behaviours of the FHSCSs are examined. It can be noticed that the foam-filled FHSCS structure exhibits a more excellent anti-vibration capability compared to the non-foam-filled structure. The solving method, fabrication technique, and valuable findings in the current study highlight the path for the design and implementation of such advanced shells. [ABSTRACT FROM AUTHOR]

The low stiffness resulting from substantial core porosity within the re-entrant honeycomb sandwich panel can be addressed by introducing rib-reinforcements. To investigate its static and vibration characteristics, an energy-based 2D equivalent-homogenization model (2D-EHM) was derived through asymptotic analysis of the leading terms in the governing equations considering the energy-related characteristics. The accuracy of the constructed model for predicting the elastic bending performance of the sandwich panel was verified by comparing the results of a three-point bending experiment with 3D-printed specimens. Comparative analysis with a 3D FE model demonstrates that the 2D-EHM exhibits maximum errors of only 4.65% and 6.46%, respectively, in analyzing static deformation and natural frequency while improving computational efficiencies by up to 59- and 173-folds. Parameter analysis reveals that the performance of SP-RRH is minimally affected by the reinforcement-to-honeycomb wall thickness ratio. However, its performance is compromised when the honeycomb walls align in an equilateral triangle with the reinforcing walls. Comparing specific stiffness as well as static and vibration characteristics of sandwich panels with different core configurations (including traditional and diamond reinforced re-entrant honeycombs) shows that inclusion of rib reinforcements enhances deformation resistance and natural frequencies through increased specific stiffness. These findings provide valuable insights for optimizing design of re-entrant honeycomb sandwich panels. [Display omitted] • VAM-based 2D model of SP-RRH accurately validated against 3D-FEM results. • Equivalent stiffness obtained via asymptotic analysis of unit cell's energy functional. • The tailorability of the unit cell facilitates the customization of its properties. • Rib-reinforcing walls enhance deformation resistance of sandwich panels. • The performance of SP-RRH is influenced by equilateral triangular cellular structure. [ABSTRACT FROM AUTHOR]

Thin-walled edge cutting angle (TWECA) refers to a unique trait of honeycomb core materials in the course of cutting, which is also a main influencing factor for the surface quality of machining. To validly overcome machining defects, making accurate TWECA prediction during the cutting process is necessary. In this study, a TWECA model for various kinds of thin-walled edges was proposed. Firstly, the thin-walled edges composing honeycomb cores were classified and unified based on the structural features of the cores, which lays the foundation for the modeling of honeycomb core architecture as well as the TWECA prediction. Then, the geometric relationships between tool and various types of thin-walled edges during contact were analyzed, and the differences in TWECAs of thin-walled edges in different tool feed directions were explored. Finally, the TWECA model accuracy was validated by using the tool mark characteristics on the machined surface as the research target. As demonstrated by findings of this research, our model achieves accurate TWECA forecasting during cutting process, thus providing a theoretical foundation for the requirements of low-damage and high-quality machining. [ABSTRACT FROM AUTHOR]

The commercialization of Li–S batteries is severely hampered by the electrically insulated nature of S and the discharge product Li 2 S, the shuttle effect of lithium polysulfides (LiPSs), and the slow redox kinetics between Li 2 S 2 /Li 2 S. Herein, a composite of Co–Ni bimetallic selenide nanoparticles embedded in honeycomb porous carbon (Co–Ni–Se@C) is prepared and used as a multifunctional interlayer on the separator to solve the above-mentioned challenges in Li–S batteries. The Co–Ni–Se@C composite with high electrical conductivity can not only accelerate Li+ and electronic transfer but also have good chemisorption and catalytic activity for LiPSs, which can maximize the utilization of sulfur active material. As expected, Li–S batteries assembled with Co–Ni–Se@C-PP separator exhibit excellent electrochemical performance, including high initial discharge capacity of 1245 mAh g−1 at 0.2 C, superior long cycling stability with a 0.066 % decay per cycle at 1.0 C, and an excellent rate capacity of 674 mAh g−1 at 5.0 C. In addition, a satisfactory capacity of 1174 mAh g−1 is achieved with a high sulfur loading of 3.7 mAh g−1 and a low E/S ratio of 10 μL mg−1. This work provides a new insight into the application of bimetallic selenides in high-performance Li–S batteries. • Co–Ni bimetallic selenides are embedded into honeycomb carbon matrices as the multifunction interlayer for Li–S batteries. • The Co–Ni–Se@C modified layer offers active sites for effective adsorption-diffusion-conversion of lithium polysulfides. • The Co–Ni–Se@C interlayer can reactivate the inactive polysulfides during cycling. • The cells with Co–Ni–Se@C interlayer exhibits high discharge capacity and good cycling stability. [ABSTRACT FROM AUTHOR]

• A central self-similar strategy is proposed to develop bio-inspired honeycombs. • Central self-similar degradable polymer honeycombs are additively manufactured. • The interaction effect of different connections between the two walls can promote EA. • Theoretical models of the proposed central self-similar honeycombs are built. At present, improving the energy absorption capacity of lightweight degradable polymer honeycombs is crucial for one of the future engineering applications and bio-inspired strategy based on hierarchy is considered an efficient method for designing honeycomb structures. To improve the energy absorption performance and stability of polymer honeycombs, this study develops three central self-similar bio-inspired honeycombs combining the microstructure of horsetails and designs different connections between the two walls and connecting structures for the central self-similar honeycombs. Bio-inspired honeycombs are fabricated using toughened polylactic acid (PolyMax™ PLA) through fused deposition modelling and subjected to axial compression tests. The finite element (FE) models of the bio-inspired honeycombs are developed to simulate the axial compression process and verified with experimental results. Results show that the connecting structures distributed on the outer wall of the central self-similar honeycombs considerably improve the energy absorption performance of the bio-inspired honeycombs. In the double-cell honeycombs, connecting structures interact with the cell walls, leading to the formation of more folding lobes on the cell walls and increased cell wall utilisation. Furthermore, the effects of geometrical parameters on the energy absorption performance of the bio-inspired honeycombs are investigated. Suitable connecting structure size and cell wall thickness can improve the energy absorption performance and stability of the honeycombs. In addition, the theoretical calculation models of the three bio-inspired honeycombs are established, and the errors with the FE calculation results are within 6 %, which verifies the accuracy of the theoretical models. [Display omitted] [ABSTRACT FROM AUTHOR]