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Inclined loading conditions cannot be avoided and strongly influence the mechanical response of honeycomb structures. In present study, deformation modes as well as dynamic responses of hexagonal honeycomb structures undergoing non-ideal oblique impact loadings have been investigated considering as significant parameters of the load angle (ranging from 0 to 10°) and the impact velocity (ranging from 3 to 70 m/s). Some new deformation phenomena and response modes have been observed. Evident influence of asynchronous loading as well as impact speed on the deformation mode evolution has been determined. Corresponding mode classification maps were constructed. The present study provides a significant advancement to the comprehensive understanding of the dynamic response of honeycombs, which could be used to develop more valuable guidelines for design purposes in cellular energy absorbing devices. [ABSTRACT FROM AUTHOR]

In this paper, we synthesize honeycomb structure titanium dioxide (TiO 2) grafted with carbon fiber (CF) composites (CF/TiO 2) for flexible supercapacitors (SCs), which evidently boosts specific surface areas (SSA) of CF. In addition, we put forward an effective strategy for enhancing conductivity of TiO 2 relying on construction of oxygen defects in NaBH 4 solution. Amazingly, the reduced-TiO 2 supporting on CF electrode (CF /R–TiO 2) obtains from optimum conditions (2 M 4h) and exhibits the highest specific capacitance of 115.2 F g−1 at 1200 mA g−1, suggesting ultra-utilization of R–TiO 2 for SC. Interestingly, its capacitance retention still remains 98.37% after 10000 cycles, which declares prominent cycling stability. Furthermore, we conduct density functional theory (DFT) analysis to reveal the enhancement mechanism of R–TiO 2. With the reduction process, Fermi energy (E F) can obviously move conduction band (CB), which indicates increments of electronic conductivity of TiO 2. Moreover, the aqueous symmetric SC based on CF/R–TiO 2 (CF/R–TiO 2 -SC) expresses a high energy density of 49.6 Wh kg−1 at a power density of 1440 W kg−1. Meanwhile, the all-solid-state flexible supercapacitor (CF/R–TiO 2 -AFSC) further presents favorable flexibility in tested bending angles. Our results demonstrate that CF/R–TiO 2 is provided with introduction of oxygen defects and honeycomb structure, which might have tremendous potential for SC. [Display omitted] • Honeycomb structure TiO 2 with oxygen defects was designed for supercapacitors. • Oxygen defects were introduced into TiO 2 by one-step NaBH 4 reduction. • Flexible CF/R–TiO 2 -SC exhibited the remarkable energy density of 48.4 Wh kg−1. • The CF/R–TiO 2 -AFSC could show favorable flexibility. [ABSTRACT FROM AUTHOR]

• The electronic structure of Sb honeycomb layer on Ag(111) is calculated with relativistic DFT. • The formation of the honeycomb structure and its stability are studied by performed Monte Carlo simulations. • The bands crossing E F loose the surface weight away from K point, so that they are not localized in the Sb adlayer in the net Brillouin zone. The electronic structure of the Sb layer on Ag(111), recently reported to have a flat (√3 × √3) honeycomb structure similar to that of graphene [Y. Shao et al. , Nano Lett. (2018) 18:2133–9], is studied by means of relativistic DFT calculations. In accordance with earlier results, a flat free Sb monolayer is found to be metastable, as follows from the existence of an imaginary phonon mode. The layer spontaneously reconstructs into a buckled honeycomb structure, which leads to the metal-to-nonmetal transition. It is suggested therefore that the formation of a flat Sb honeycomb layer becomes possible just because of the substrate-induced tensile strain, which results in the stabilization of the structure. The binding (adsorption) energy per Sb atom for the honeycomb structure is found to be rather strong, 4.61 eV, which can be explained by a significant lateral attraction between Sb adatoms. The formation of the honeycomb structure and its stability are studied by performed Monte Carlo simulations within the lattice-gas model either with account for trio interactions, or with some effective energy parameters. The SOC only slightly changes the band structure of the system, but, due to pronounced downward shift of the cone-like band in vicinity of K point, leads to the second surface band crossing E F. A detailed analysis of the localization of the wave functions indicates that the bands crossing E F loose the surface weight away from K point, so that they are not localized in the Sb adlayer in the net Brillouin zone. Left: The snapshots and related LEED patterns obtained in the course of Monte Carlo simulations, Right: The band structure of the honeycomb Sb monolayer on Ag(111). The localization of the wave functions for a few characteristic states is illustrated by electron density distributions shown in inserts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-folded honeycomb structure (SHS) was fabricated via stimuli-responsive materials. • Origami-inspired design for SHSs with energy-absorption properties was established. • Relationship of design, structure, and compression performance was elucidated. • Energy-absorption of 5-layered SHS was 6.67 times higher than that of 1-layered SHS. • Damage factor for protected object was successfully removed via pre-straining. The origami technique has been employed in the medical, space, and agricultural industries owing to its low cost and ease of use. In particular, the use of stimuli-responsive materials to automate origami fabrication has garnered interest. In this study, self-folded honeycomb structures (SHSs) were fabricated using the self-folding technique. A sheet of paper undergoes self-folding without human intervention via the physicochemical reactions between the paper and printing solution. Six SHSs with different mechanical properties were fabricated. The relationship between the design and structural parameters was examined. The energy-absorption performance of the structure improved by a factor of 15.2 on employing the optimal parameters. A consistent relationship between the design and compression performance was also discussed. By applying stacking technology, the energy-absorption performance increased by an average of 1753 N·mm per layer. The application of a pre-strain eliminated the compressive force peak that could damage the protected object, while maintaining 90 % of the energy-absorption performance. The proposed technology shows potential for the fabrication of tailored energy absorbers using stimuli-responsive materials, providing a groundbreaking technology for the packaging industry. [ABSTRACT FROM AUTHOR]

One of the advantages of emerging additive manufacturing is providing opportunities to build parts with complex geometries. The microstructure and compressive response of Hastelloy X Ni-based superalloy honeycomb lattiaces fabricated by laser powder-bed fusion additive manufacturing is evaluated. The microstructural studies indicated that the as-built sample consisted of submicron cells with random orientations embedded in columnar austenite grains. The STEM-EDS observations revealed that the cell walls contained dense dislocation tangles rich in Mo and Cr elements compared to the cell interior. After the heat treatment at 1175 °C for 2 h, the partial recrystallization via twinning-assisted nucleation mechanism replaced some columnar grains with equiaxed ones. In addition, EBSD investigations illustrated that the recrystallized grains retained the texture of the parent grains, leading to the reduction of recrystallization kinetics through the creation of low-mobility boundaries. Upon the compression testing, the honeycomb samples showed stretch-dominated type behavior. The fractography results indicated that the initiation of cracks from the outer and inner surfaces of the honeycomb's walls was the failure mechanism of both as-built and heat trated honeycomb samples. Moreover, the compressive performance of the samples was slightly improved after heat treatment. [ABSTRACT FROM AUTHOR]

The mechanical behaviors of honeycomb cores subjected to out-of-plane compressive loading were studied based on the deformation of cell walls. Four types of honeycomb structures, with and without panels, were experimentally, theoretically, and numerically investigated, respectively. In addition to the deformation of outer sidewalls, the stereovision three-dimensional digital image correlation (3D-DIC) method was first applied to determine the deformation process of the inner sidewalls. A coaxial 3D-DIC was developed to obtain the full-field displacements and strain distributions of the inner sidewalls. The compression strength of the structures was predicted successfully by the theoretical elastic buckling strength. Moreover, the onset of the damage process was simulated with finite element calculations, which agreed well with experimental data. Therefore, this study provides a better understanding on the behavior of honeycomb structures from the deformation of outer and inner surfaces. [ABSTRACT FROM AUTHOR]

The synthesis of IrI 3 at high pressure in its layered honeycomb polymorph is reported. Its crystal structure is refined by single crystal X-ray diffraction. Faults in the honeycomb layer stacking are observed by single crystal diffraction, synchrotron powder diffraction, and transmission electron microscopy. A previously unreported "hyperhoneycomb" polymorph of IrI 3 (β -IrI 3), is also reported - Its structure in space group Fddd is determined by single crystal XRD. Both materials are highly-resistive diamagnetic semiconductors, consistent with a low spin d 6 configuration for Ir(III). The two- and three-dimensional Ir arrays in these polymorphs of IrI 3 are analogous to those found in the α- and β- polymorphs of Li 2 IrO 3 , although the Ir electron configurations are different. IrI 3 may be of future interest in the fabrication of new quantum materials. IrI 3 has been synthesized in both its previously reported layered form and in a previously unreported polymorphic form by a solid-state high-pressure method. Both of the crystal structures are refined by single crystal XRD. Their structural, physical, and optical absorption properties are characterized, which are consistent with the d 6 configuration of Ir(III) and their calculated electronic band structures. [Display omitted] • Honeycomb layered α-IrI 3 is successfully synthesized at a moderately high pressure. • A new IrI 3 polymorph with a 3D hyperhoneycomb structure is formed and discovered. • Both polymorphs are measured to be highly resistive diamagnetic semiconductors. [ABSTRACT FROM AUTHOR]

Honeycomb 3D graphene-like Co 9 S 8 nanocrystallines were successfully synthesized using cobalt and Na 2 S·9H 2 O as starting materials without a template via a simple hydrothermal route. The composition, structure, morphology, and catalytic activity of the as-prepared Co 9 S 8 were characterized by investigation of XRD, SEM, EDS, XPS, GC–MS and HPLC. It was found that an appropriate concentration of inexpensive NaHCO 3 play a critical role for the formation of honeycomb Co 9 S 8 nanocrystallines. On the other hand, Co 9 S 8 acted as a catalyst in the hydrothermal reaction, producing formic acid reduced from NaHCO 3 as high as 3680 mg/L. It indicates that the present study not only proposes a simple way of honeycomb Co 9 S 8 synthesis, but also provides a potential approach to CO 2 reduction. [ABSTRACT FROM AUTHOR]

Crashworthiness optimization of aircraft and automotive structures has become one the main research targets for their respective leading industries. The following research proposes a new design of an aircraft’s vertical strut. The design consists of a hollow aluminum square tube with a glass-fiber reinforced polymer honeycomb-shaped inner structure. Size and shape surrogate-based optimization techniques are used, with the thicknesses of both materials, cell size and cell shape as design variables. The objective function chosen for the single-objective optimization is the specific energy absorption, while the metrics for the multi-objective optimization are the peak force, mass, absorbed energy and the specific energy absorption. An improvement of 22% of the specific energy absorption with low peak force values is obtained from the single-objective optimization by significantly changing all design variables. Two Pareto fronts have been obtained from the multi-objective optimization confronting, the specific energy absorption against the peak force and the mass against the energy absorbed. When compared to the baseline model, the optimized models show substantial improvement, increasing the specific energy absorption by 65% or reducing the peak force by over 55%. It has been observed an important effect of the cell shape on the model’s performance. [ABSTRACT FROM AUTHOR]

Honeycomb structures, inspired from bee honeycombs, had found widespread applications in various fields, including architecture, transportation, mechanical engineering, chemical engineering, nanofabrication and, recently, biomedicine. A major challenge in this field is to understand the unique properties of honeycomb structures, which depended on their structures, scales and the materials used. In this article, we presented a state-of-the-art review of the interdisciplinary efforts to better understand the design principles for products with honeycomb structures, including their fabrication, performance (e.g., mechanical, thermal and acoustic properties) as well as optimization design. We described how these structural perspectives have led to new insights into the design of honeycomb structures ranging from macro-, micro- to nano-scales. We presented current scientific advances in micro- and nano-technologies that hold great promise for bioinspired honeycomb structures. We also discussed the emerging applications of honeycomb structures in biomedicine such as tissue engineering and regenerative medicine. Understanding the design principles underlying the creation of honeycomb structures as well as the related scientific discovery and technology development is critical for engineering bioinspired materials and devices designed based on honeycomb structures for a wide range of practical applications. [ABSTRACT FROM AUTHOR]

This study proposed an effective structure for the cathode of SOFC to reduce resistance, the honeycomb structure with dual porosity (micro and macro pores). A Sm 0.5 Sr 0.5 CoO 3−δ (SSC)–Sm 0.2 Ce 0.8 O 2−δ (SDC) composite cathode for solid oxide fuel cells, with a noble honeycomb structure comprising of nano and micro-sized pores, was fabricated by electrostatic slurry spray deposition (ESSD). The macro-pores distribute in the whole film with size range of 5–20 μm and micro-pores were formed throughout the skeleton with the size under 1 μm. This dual porosity composite cathode from interface to surface of the electrode was deposited by electrostatic slurry spray deposition (ESSD). Its electrochemical property was evaluated using electrochemical impedance spectroscopy and turned out to be enhanced compared to a conventional porous structure of cathode. The polarization resistances were significantly decreased with increasing measurement temperature. [ABSTRACT FROM AUTHOR]

Honeycomb composite structures are increasingly being used in the aviation and aerospace industries. For convenient quality evaluation of such advanced composites, several kinds of non-contact non-destructive testing techniques are widely used and are proving to be promising tools for the integrity assessment of honeycomb composites. In this study, the detection performance of air-coupled ultrasonic pulse compression C-scan, lock-in thermography and X-ray digital radiography methods for the characterisation of typical defects in honeycomb composite structures is analysed. For this purpose, three honeycomb composite samples with simulated inclusions or disbonds are prepared and experiments are conducted using the different methods. The contrast-to-noise ratio (CNR) is used to evaluate the image quality and a typical threshold method is used to determine the minimum detectable defect size using the specific testing method. In addition, the features of the different methods are summarised. Finally, the advantages and limitations of the three non-contact non-destructive testing techniques for the evaluation of honeycomb composites are discussed based on the experimental results and basic conclusions are also drawn for the preferred approach in inspecting for particular defect types. [ABSTRACT FROM AUTHOR]

Experimental results on the detection of latent water in a honeycomb fiberglass structure using terahertz thermography are presented. These data are compared with data that were obtained using active infrared thermography. [ABSTRACT FROM AUTHOR]

[Display omitted] • PLA/TPU filament for 3D printing was obtained by a screw extruder. • Continuous carbon fiber reinforced PLA/TPU honeycomb structure was prepared. • The self-sensing of strain and damage during cyclic compression was investigated. • The self-sensing of temperature change of honeycomb structure was achieved. Polylactic acid/thermoplastic polyurethanes (PLA/TPU) filament for 3D printing was prepared by screw extruder, and continuous carbon fiber-reinforced PLA/TPU honeycomb structure was fabricated by continuous fiber 3D printer, and the self-sensing performance of the structure during cyclic compression was investigated. The results show that the strain and damage can be sensed by the change of electrical resistance in the honeycomb structure during cyclic compression at small-strain (ε = 0.04) and large-strain (ε = 0.4). Meanwhile, the temperature monitoring of the honeycomb structure can be realized by the change of electrical resistance in the honeycomb structure. This study provides the possibility for developing and applying 3D printed continuous carbon fiber composite smart structures and structural health monitoring. [ABSTRACT FROM AUTHOR]

This paper reports the effect of temperatures (30℃ to 80℃, with incremental steps of 5℃) and orientations of the glass fibers (0°, 30°, 45°, 60° and 90°) on the dynamic properties (the loss factors and the natural frequencies) of polypropylene honeycomb sandwich composites. The impulse technique has been employed to calculate the natural frequency and loss factor of the sandwich specimens under different temperatures. The natural frequency and loss factor values have also been calculated theoretically using Blevins's formulae for natural frequency, and Yim et al.'s transverse shear effect, respectively. The values of damping loss factor and the natural frequency/stiffness are the maximum at 0° fiber orientation in the skins of the sandwich specimen. The loss factor of the same oriented specimen increases sharply with the increase in temperature. The main reasons for the above are the higher in-plane strength of skins and lower transverse shear strength of the honeycomb core. Hence, the 0° fiber oriented sandwich specimen is more desirable than the other fiber oriented specimens at all temperatures. A good agreement is observed between the experimental and theoretical values. [ABSTRACT FROM AUTHOR]

In this paper, by using the piezoelectric material, the active aeroelastic flutter characteristics and vibration control of supersonic sandwich panels with different honeycomb interlayers, resting on an elastic foundation, are studied. Classical beam theory along with the Winkler-Pasternak foundation model, and the quasi-steady first order supersonic piston theory are employed in the formulation of the structural theory and aerodynamic loading, respectively. Hamilton's principle in conjunction with the generalized Fourier expansions and Rayleigh-Ritz (RR) method are used to develop the dynamical model of the structural systems in the state-space domain. The aeroelastic flutter bounds are obtained via the p-method. The classical Runge-Kutta integration algorithm is then used to calculate the open-loop aeroelastic response of the system under different loading excitations. Finally, two classical control strategies, including direct proportional feedback and linear-quadratic regulator (LQR) optimal control scheme, are used to actively suppress the closed loop system response, while increasing the flutter aerodynamic pressure. [ABSTRACT FROM AUTHOR]

In this paper, the honeycombed top-porous/bottom-tubular TiO 2 nanotube arrays (TiO 2 NTs) were prepared by a facile two-step anodization method. The structural parameters of honeycombed TiO 2 NTs can be well controlled by adjusting the voltages in the second-step anodization process, and the honeycombed TiO 2 NTs showed much enhanced photocatalytic activity than the conventional 1-step TiO 2 NTs. [ABSTRACT FROM AUTHOR]

A novel strategy to prepare thick nanofibrous scaffolds with controlled pore size and graded porosity by electrospinning was developed. Taking advantage of the self-assembling properties of bimodal nanofibers, it was possible to grow columns of pores with mm height. The use of a honeycomb microstructured collector allows the control of the pore diameter from 80 to 360 µm. With increasing sample thickness, the columns of pores begin to merge creating a gradient in pore diameter of up to several hundreds of microns. These scaffolds should be ideal for tissue engineering applications. [ABSTRACT FROM AUTHOR]

We demonstrated a facile approach for synthesizing three-dimensional (3D), honeycomb-structured graphene scaffold in the solid flame of a (0.5+ k ) Zn+ k CuO+(CH 2 -CHCl)n reaction system. FESEM-based analyses of the acid purified porous graphene samples revealed that the synthesized graphene had a 3D, honeycomb-like structure with cell sizes of 20–100 nm and wall thicknesses of 1–3 nm. The specific surface area of the graphene sample prepared in the solid flame was about ~1043 m 2 /g). [ABSTRACT FROM AUTHOR]

Simple monatomic amorphous 2D models with Honeycomb structure are obtained from 2D simple monatomic liquids with Honeycomb interaction potential (Rechtsman et al., Phys. Rev. Lett. 95, 228301 (2005)) via molecular dynamics (MD) simulations. Models are observed by cooling from the melt at various cooling rates. Temperature dependence of thermodynamic and structural properties including total energy, mean ring size, mean coordination number is studied in order to show evolution of structure and thermodynamics upon cooling from the melt. Structural properties of the amorphous Honeycomb structures are studied via radial distribution function (RDF), coordination number and ring distributions together with 2D visualization of the atomic configurations. Amorphous Honeycomb structures contain a large amount of structural defects including new ones which have not been previously reported yet. Cooling rate dependence of structural properties of the obtained amorphous Honeycomb structures is analyzed. Although amorphous graphene has been proposed theoretically and/or recently obtained by the experiments, our understanding of structural properties of the system is still poor. Therefore, our simulations highlight the situation and give deeper understanding of structure and thermodynamics of the glassy state of this novel 2D material. [ABSTRACT FROM AUTHOR]

An innovative design, alternative to the conventional metal supported fuel cells (MSC) is proposed. This new design of Solid Oxide Fuel Cell (SOFC), comprises a 200 μm layer of a honeycomb-metallic framework with hexagonal cells which supports a 250 μm layer of electrolyte. Each hexagonal cell is further functionalized with a thin 5–10 μm of Ni–YSZ anode. This new design allows a reduction of ∼65% of the metallic supporting material, rendering performances over 300 mW cm −2 under pure hydrogen at 850 °C, with an OCV of ∼1.1 V. [ABSTRACT FROM AUTHOR]

Fuel efficiency and occupant safety are two of the most important concerns in the automotive industry nowadays. Encouraged by the importance of this field of study, this research attempts an improvement in the crashworthiness of a vehicle crash absorber. This component consists in a square hollow steel tube filled with a honeycomb structure made of glass-fiber reinforced polyamide. Surrogate-based optimization techniques are used. The three objective functions chosen — mass, absorbed energy and peak load — are approximated by two different models: multivariate adaptive regression splines and Gaussian process (kriging). The thickness of both parts, the shape of the honeycomb and its height are selected as design variables. Two preliminary analyses of the specimen are performed: the computation of the interaction effect and a comparison of a hollow tube with the specimen. From the results of multi-objective crashworthiness optimization two Pareto frontiers are obtained, one for the absorbed energy and mass, and another one for the absorbed energy and peak load. The results achieved show great improvements on all objective functions compared to the original design. The peak load is reduced by 37% on a specimen with similar mass and absorbed energy, and the specific energy absorbed is increased by 39.5% for a specimen with a similar peak load to the one from the initial model. [ABSTRACT FROM AUTHOR]

A model able to predict the delamination mechanisms of composite honeycomb structures under thermal loading is presented. The use of a simulation software for some applications may not be sufficient to obtain the results expected; hence, the interest in developing modular calculation codes which would allow one to determine the rigidity matrix of a honeycomb panel, the deformation of its members, the field of shear strains, strains, and stresses in the panel plane on varying the physical parameters and checking the strength of each layer and of the entire panel. In order to test the reliability of the program developed, the results obtained are compared with those given in the literature. A specific model of Young's modulus under thermal loads is proposed, which takes into consideration the heat flux function, the thermal conductivity, the convection heat-transfer coefficients of the surrounding area inside and outside the panel, the exchange area in contact with air, the thickness of the honeycomb core, the upper and lower skins, and the adhesive layer. To verify the fracture strength of each panel, the Tsai-Wu criterion is used. [ABSTRACT FROM AUTHOR]

We built the honeycomb networks of misfit dislocations by combining angular dislocations. Two different models of the disorder in the dislocation network are explored, the random shifts of nodes and random sources of distortion. The displacement fields of disturbed dislocation networks are used to simulate the X-ray diffraction patterns by Monte Carlo method. We find that substantial disorder is needed for random shifts to be experimentally observable as diffuse scattering. The model of random distortion sources produces comparable diffuse scattering with the dislocation network looking closer to the initial perfect structure. The diffraction patterns due to distorted honeycomb dislocation networks are compared with the ones due to triangular networks of straight dislocations. The disorder parameters of the latter networks can be chosen to produce diffraction patterns similar to the former. [ABSTRACT FROM PUBLISHER]

A new design of an optical isolator based on photonic transitions in the interbands of a honeycomb structure that generates a dual negative refraction in a photonic crystal is presented. The involved photonic transition is associated to the perturbation of the dielectric constant of the medium. The band structure is determined using the plane wave method where the transmission spectra, field profile, and mode amplitudes are obtained by applying the finite difference time domain method. Due to the time-dependent perturbation of the refractive index of the medium that constitutes the dual negative refraction, asymmetric transmission mechanism is achieved for one of the desired modes, demonstrating optical isolation. Using the dual negative refraction effect in photonic crystal structure, the optical isolation is reported for only one of the desired optical modes. It is anticipated that the proposed mode conversion mechanism can be employed for designing ultrahigh-speed optical interconnections. The proposed optical isolator model is expected to have a significant impact on designing ultrahigh-speed integrated optical platforms. [ABSTRACT FROM AUTHOR]

With booming development of 5G communications and electronic devices, electromagnetic waves (EMWs) radiation pollution has aroused much concern on public, and great efforts are being made to develop the high-performance electromagnetic interference shielding (EMI SE) materials. However, inherent deficiencies of traditionally processing technology restrain the current materials to fabricate desirable architectures for SE applications. Herein, taking full advantages of 3D printing in free-construction, architected honeycombs featuring lightweight and high-efficient EMI SE are designed with polylactic acid (PLA) as matrix, and graphene nanosheets and carbon nanotubes hybrids (GNs/CNTs) as functional fillers. The optimal printed material shows a high electrical conductivity up to 110.8 S/m and outstanding EMI SE property of 53.5 dB, far exceeding the standard of commercially shielding materials (20 dB). More encouragingly, this work makes a deep insight into the intrinsic connection of porous structure of 3D-printed components on shielding mechanism, which reveals that as the pore size is far less than a certain proportion of incident wavelength (λ/5), the components exhibit a good reconcilability on the lightweight (0.4–1.0 g/cm3) and high-performance EMI SE (35–45 dB). From fundamental materials to desirable components, this breakthrough lays a solid foundation for the free-construction of diversified architectures in EMI SE applications. [Display omitted] • The strong conductive networks are constructed by the hybridization of graphene nanosheets and carbon nanotubes. • The hybrid networks endow the 3D-printed components with superior electromagnetic interference shielding (∼53.5 dB). • The diameter of porous structures should be less than the 1/5 of incident wavelength (λ) to shield electromagnetic waves. • The 3D-printed honeycombs exhibit a good reconcilability on lightweight and electromagnetic interference shielding. [ABSTRACT FROM AUTHOR]

The structural design of gradient is universally considered to be an effective approach to improve the performance of cellular materials. In this study, the selective laser melting (SLM) was used to fabricate honeycomb components with different gradient configurations and gradient values. The influences of configurations and gradients on the manufacturability, microstructure evolution, and compression behavior were comprehensively investigated. The numerical simulation was conducted to study the deformation mechanism of honeycombs with different configurations. Results revealed that the small wall-thickness caused pore defect and reduced the relative material density of honeycomb components. The variation of the cooling rate of different building parts led to different size of grains. Different configurations and gradients greatly affected the compression behavior of gradient honeycombs. The symmetric positive gradient (SP) configuration exhibited the most excellent compression performance with the highest mean crushing strength, densification strain and CEF. With the increase of gradient values, the compression strength of gradient honeycombs greatly decreased, while the densification strain enhanced visibly. The elevation of gradient values also obviously increased the energy absorption capacity of honeycomb structures, up to 20.41%. The effect of the structure relative density on the compression properties was studied by the numerical simulation. With the increase of the structure relative density, the specific compression strength and the specific energy absorption apparently rose. • Continuous gradient honeycomb structures were fabricated by selective laser melting. • Four different gradient configurations and gradient values were designed. • Microstructure was studied and closely related to the deformation mode. • Increase of gradient values notably improved the energy absorption capacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The synthesis of Ni-Co LDH/G composite was largely optimized by microwave method. • Honeycomb structure guarantee its excellent electrochemical property. • Orbitals hybridization effect of composite contribute to the enhanced rate property. Nickel cobalt layered double hydroxide (Ni-Co LDH) is an exciting new electrode material because of its high theoretical capacity and redox activity. However, the complicated synthesis process and the intrinsically low conductivity impede its large-scale commercial application. Hence, a high-efficiency microwave liquid synthesis method was employed to rapidly prepare honeycomb-structured Ni-Co LDH nanosheets on graphene (Ni-Co LDH/G) composite, within minutes range of synthesis time. By introducing graphene, the poor intrinsic conductivity of the Ni-Co LDH could be ameliorated by hybridization effect, as reveled by density functional theory calculations, thus enhancing the rate capability greatly: Ni-Co LDH/G composite retained 87.1% of capacity at high rate, whereas only 50.5% was retained for Ni-Co LDH. In addition, the hybrid supercapacitor with Ni-Co LDH/G//activated carbon could deliver a high energy density of 40.6 Wh kg−1 at 400 W kg−1, along with a stable cycling lifespan with 83.2% of capacity retention after 10,200 cycles. These encouraging findings highlight that microwave synthesis could be an efficient route to engineer coordinating Ni-Co LDH/G composite for advanced electrode materials in supercapacitors. [ABSTRACT FROM AUTHOR]

• Co/Carbon (Co/C) composites were prepared by facile hydrothermal and calculation process. • Modulating permeability of Co/C is achieved by adjusting the amount of Co2+. • The obtained Co/C composite exhibits a bandwidth of 5.8 GHz at a low thickness of 1.8 mm. • The electromagnetic simulated honeycomb made by Co/C shows an ultrabroad bandwidth of 11.6 GHz. [Display omitted] Confronting with increasing electromagnetic pollution, traditional microwave absorbing materials have their limitations, such as low yield and long preparation periods. At the same time, it is well established that electromagnetic simulation is an effective technology to enhance work efficiency, which can quickly explore the impedance matching conditions and electromagnetic characteristics to improve absorbing performance. Honeycomb structure has been widely used in the field of microwave absorption due to its light weight, high strength and heat resistance. This structure also possesses the advantages of multiple scattering, which is beneficial to microwave attenuation. In this work, Co/carbon (Co/C) particles with effective absorption bandwidth (EAB) (the band corresponding to the reflection loss value less than −10 dB) of 5.8 GHz were synthesized by a simple hydrothermal method. Whereupon through the high-frequency structure simulator (HFSS) electromagnetic simulation, Co/C absorbers with honeycomb structure were macroscopically designed, achieving an ultra-broad effective absorption bandwidth of 11.6 GHz. Herein, the effective combination of electromagnetic simulation and honeycomb structure design greatly improves the absorption bandwidth of Co/C. This work paves the way for designing microwave absorption materials with broad effective absorption bandwidth. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrothermal scanners have limited bandwidth due to a large thermal time constant. • Scanner's thermal and inertial mass is reduced using the honeycomb support structure. • As a result, an increase in both bandwidth and efficiency of a scanner is demonstrated. • A sample two-photon 3D images of pollen grain are taken on benchtop system. Design and testing of a low-mass electrothermal vertical scanning mirror for fast axial scanning during multi-photon microscopy is presented. The mirror makes use of a novel honeycomb mechanical support structure to substantially reduce both thermal and inertial mass relative to mirror size. At the same time, undesirable mirror curvature due to residual thermal stress is controlled without adversely affecting the image quality. In addition, the support structure makes the complete mirror area usable which otherwise is not possible in devices that rely on isotropic silicon etching. A high actuator efficiency with static displacement per unit power of 2.08 μm/mW was achieved due to the reduced thermal capacitance at the actuator legs, when using a 700 nm thin structural layer of SiO 2. The resulting scanning mirror achieves open loop time constant as small as 3.42 ms with both thermal and mechanical bandwidths exceeding 100 Hz. Mirror surface non-idealities related to the mirror structure and their influence on image quality are discussed. Sample 3D multi-photon images captured by performing remote scanning in both lateral and axial direction on a benchtop testbed are presented. The efficacy of remote axial scan is ascertained by comparisons with images obtained by moving specimens relative to the objective. [ABSTRACT FROM AUTHOR]

More than 110,000,000 tons of mismanaged plastics were to be produced in 2020. Polymers are favored in the preparation of thermally conductive materials due to their excellent comprehensive properties. However, most polymers fabricated for thermally conductive materials are difficult to degrade in the natural environment. To alleviate the increasingly severe environmental problems, we reported a novel eco-friendly material with high thermal conductivity, which was composited of chitosan microspheres (CSM) and hydroxyl-functionalized hexagonal boron nitride (OH-h-BN) nanoplatelets. Utilizing their significant difference in scales, the OH-h-BN nanoplatelets were arranged between each CSM. Their overall structure was similar to the honeycomb: CSM were honeycomb cores, and OH-h-BN nanoplatelets were honeycomb network. The routine-structure OH-h-BN/CS nanocomposites were only 0.94 ± 0.02 W·m−1·K−1 at 50 wt% in thermal conductivity. However, the OH-h-BN/CSM nanocomposites with honeycomb structure can reach 5.66 ± 0.32 W·m−1·K−1 in the same loading, for enhancement of 502% and 1914% than OH-h-BN/CS nanocomposites and pure CS, respectively. [Display omitted] • Chitosan microspheres (CSM) were reported as the substrate for heat conduction. • OH-h-BN/CSM nanocomposites possess the particular honeycomb network structures. • The thermal conductivity of OH-h-BN/CSM nanocomposites can reach 5.66 W·m−1·K−1. [ABSTRACT FROM AUTHOR]

In order to efficiently evaluate and design honeycomb structures with excellent energy-absorbing ability, in-plane dynamic response and multi-objective optimization of negative Poisson's ratio (NPR) honeycomb structures with sinusoidal curve are performed in this work. By establishing the in-plane impact finite element model, the deformation modes and in-plane dynamic responses of the sinusoidal NPR honeycomb structures under different impact velocities are detailed studied. And the geometric parameters (e.g., the amplitude and period) of the sinusoidal curve that affect the energy absorption performance of the structure are analyzed. Combining the optimal latin hypercube design method with the double-points infilling criterion, the high-precision adaptive Kriging models of the peak crush force (PCF) and the specific energy absorption (SEA) with respect to the amplitude and period are constructed. And then, a multi-objective crashworthiness optimization is carried out by non-dominated sorting genetic algorithm (NSGA-II). The Pareto optimal solution set is gained and the final compromise solution is then obtained based on the fitness function. The optimized results show the PCF of the sinusoidal NPR honeycomb structure decreases by 30.53%, while the SEA increases by 38.55%. It indicates that the optimized sinusoidal honeycomb structure has better energy absorption performance than the conventional concave hexagonal honeycomb. The results can provide some important design guidance for other honeycomb energy-absorbing structures. [ABSTRACT FROM AUTHOR]

• Rubber-based composite films with different heterogeneous architectures were achieved. • Honeycomb structure Ti 3 C 2 T x /NR composite films were obtained after DCP curing. • Vulcanization treatment is more conducive to the enhancement of EMI shielding. • Mechanical properties of the crosslinked composite films were accordingly increased. The high performance Ti 3 C 2 T x MXene/natural rubber (NR) composite films with brick–mortar and honeycomb structure are successfully fabricated by a facile pressured-extrusion filtration process and the subsequent curing treatment. The microstructure of the Ti 3 C 2 T x MXene/NR composite films with heterogeneous architectures changed from brick-mortar to honeycomb structures after vulcanization reaction. The brick–mortar structure Ti 3 C 2 T x /NR composite film possesses superior EMI shielding performance with the shielding effectiveness (SE) of 57.1 dB and excellent mechanical properties of a tensile strength of 28.5 MPa. It's interesting to note that both EMI shielding and mechanical properties of the composite films with honeycomb structure showed significant improvement after curing process compared with those of brick–mortar counterparts, which exhibit the ultrahigh EMI SE of 63.5 dB and optimal mechanical tensile strength of 39.5 MPa. We believe that this work will provides a new idea for the production of high-performance rubber-based EMI shielding materials. [ABSTRACT FROM AUTHOR]

In order to avoid the stress shielding phenomenon in orthopedic bionic bone implantation, it is necessary to consider the design of mechanical compatible implants imitating the host bone. In this study, we developed a novel cancellous bone structure design method aimed at ensuring the mechanical compatibility between the bionic bone and human bone by means of computer-aided design (CAD) and finite element analysis technology (specifically, finite element modeling (FEM)). An orthogonal lattice model with volume porosity between 59% and 96% was developed by means of CAD. The effective equivalent elastic modulus of a honeycomb structure with square holes was studied by FEM simulation. With the purpose of verifying the validity of the cancellous bone structure design method, the honeycomb structure was fabricated by selective laser sintering (SLS) and the actual equivalent elastic modulus of the honeycomb structure was measured with a uniaxial compression test. The experimental results were compared with the FEM values and the predicted values. The results showed that the stiffness values of the designed structures were within the acceptable range of human cancellous bone of 50–500 MPa, which was similar to the stiffness values of human vertebrae L1 and L5. From the point of view of mechanical strength, the established cellular model can effectively match the elastic modulus of human vertebrae cancellous bone. The functional relationship between the volume porosity of the nylon square-pore honeycomb structure ranging from 59% to 96% and the effective elastic modulus was established. The effect of structural changes related to the manufacture of honeycomb structures on the equivalent elastic modulus of honeycomb structures was studied quantitatively by finite element modeling. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2) is a widely used biomaterial. It is a great challenge to confer antibacterial and antithrombotic properties to TiO 2 while maintaining its cell affinity. Here, we developed a new strategy to achieve the above goal by comprehensively controlling the chemical cues and geometrical cues of the surface of TiO 2. Using colloidal etching technology and UV irradiation treatment, we obtained the photofunctionalized nano-micro-honeycomb structured TiO 2. The honeycomb structured increased the photocatalytic activity of TiO 2 , which endowed TiO 2 with photo-induced superhydrophilicity to inhibit bacterial adhesion. The high photocatalytic activity also induced the strong photocatalytic oxidation of TiO 2 surface organic adsorbates to suppress fibrinogen and platelet attachment. In addition, owing to the micropore trapping-isolation effect on the bacteria and the nano-frames' contact guidance effect on the growth and spreading of platelet pseudopods, the honeycomb structure also shows a considerable inhibiting effect on bacterial and platelet adhesion. Therefore, due to the controlled chemical and geometrical cues' synergistic effect, the photo-functionalized TiO 2 honeycomb structure shows excellent bacterial-adhesion resistance and antithrombotic properties. More importantly, the photo-functionalized TiO 2 honeycomb did not inhibit the adhesion and growth of endothelial cells (ECs) after culturing for 3 d, indicating a good cell affinity that the traditional antifouling surfaces do not possess. [Display omitted] • TiO 2 honeycomb structures with micro-pores and nano-frames were fabricated. • TiO 2 Honeycomb showed improved antibacterial/ anticoagulant ability and cell affinity. • Photofunctionalized TiO 2 honeycomb showed excellent antibacterial/ anticoagulant ability and good cell affinity. • The synergistic effect of photofunctionalized TiO 2 and honeycomb structure on bacterial, platelets, and cells' adhesion was discussed. [ABSTRACT FROM AUTHOR]

Since brittle intermetallic compounds can form during soldering of nickel-based alloys, the microhardness in the area of the solder material is increased. This can be observed when joining thin-walled honeycomb structures. They are used as stationary component in sealing systems of gas turbine engines. Both the increase in the microhardness and the volume fraction of the solder material are assumed to threaten the integrity of the rotating sealing component if contact (rubbing) between the two components occurs during engine operation. To predict the impact of the solder material on the structure-property relationship of the nickel-based honeycomb structure, a micromechanical modelling approach is presented in this work. The three-dimensional micromechanical modelling approach comprises a composite of two distinct materials, the cell-wall and the solder material. The constitutive behaviour of the ductile cell-wall material is modelled with a crystal plasticity approach. A purely elastic material behaviour is assumed for the brittle solder material. For an efficient simulation, the investigated domain is restricted to the unit cell of the honeycomb composite. The studies show that with increasing volume fraction of the solder material, both thermal and mechanical loads of the honeycomb composite increase significantly, raising the likelihood of damage to the material of the rotating sealing component. [ABSTRACT FROM AUTHOR]

Cellular solids are known to exhibit size effects, i. e. differences in the apparent effective elastic moduli, when the specimen size becomes comparable to the cell size. The present contribution employs direct numerical simulations (DNS) of the mesostructure to investigate the influences of porosity, shape of pores, and thus material distribution along the struts, and orientation of loading on the size effects and effective moduli of regular honeycomb structures. Beam models are compared to continuum models for simple shear, uniaxial loading and pure bending of strips of finite width. It is found that the honeycomb structure exhibits a considerable anisotropy of the size effects and that honeycomb structures with circular pores exhibit considerably stronger size effects than those with hexagonal pores (and thus straight struts). Positive (stiffening) size effects are observed under simple shear and negative (softening) size effects under bending and uniaxial loading. The negative size effects are interpreted in terms of the stress-gradient theory • Systematic study of size effects in honeycomb structures under shearing, uniaxial loading and bending. • Comparison between beam models and fully resolved structures. • Considerable influence of pore shape on size effect. • Anisotropic size effects. • Interpretation of negative size effects in terms of stress-gradient theory. [ABSTRACT FROM AUTHOR]

Surface engineering of polymeric membranes can induce subtle changes in membrane properties and enhance their performance. Numerous membrane surface modification methods have been developed to improve the material performance. However, these methods can be complex, thus limiting their practical applications. Herein, we present a simple method for fabricating membranes with honeycomb surfaces by controlling the polymer molecular weight (M w). Spirobisindane-based intrinsically microporous poly(ether-ether-ketone) (iPEEK-SBI) homopolymers with low and high M w s were synthesized and used to prepare organic solvent nanofiltration (OSN) membranes. The significant effects of polymer M w on its physical properties, membrane morphology, and OSN performance were systematically investigated. iPEEK showed excellent solution processability, high Brunauer–Emmett–Teller surface area, and remarkable thermal stability. Three mechanically flexible OSN membranes exhibiting honeycomb surfaces with different honeycomb cell sizes were prepared using iPEEK-SBI homopolymers with low M w s at concentrations of 27–39 wt% in N -methyl-2-pyrrolidone. By contrast, the use of iPEEK-SBI homopolymers with high M w s yielded membranes with flat surfaces. The M w cutoffs of the membranes were fine-tuned in the range of 408–772 g mol−1 by adjusting the dope solution concentration. Although the M w cutoffs were unaffected by polymer M w , the membranes derived from the polymer with low M w exhibited substantially higher solvent permeance (18%–26%) than that of the high M w membrane prepared at the same dope solution concentration. Stable performance was demonstrated over seven days of continuous cross-flow filtration and a six-month aging of the membranes. This work shows the importance of surface engineering for OSN membranes by adjusting polymer M w. These findings open a new avenue for fine-tuning the properties of OSN membranes. Image 1 • Membranes prepared using intrinsically microporous poly(ether-ether-ketone). • Polymer molecular weight affects physical properties and membrane morphology. • Flat vs. honeycomb membrane surfaces studied via computational fluid dynamics. • Dope solution concentration affects honeycomb structure and Feret diameter. • Honeycomb surface demonstrate high thermal stability and stable performance. [ABSTRACT FROM AUTHOR]

• Thermo-mechanical buckling analysis of a honeycomb plate is studied. • Quasi-3D hyperbolic shear deformation theory which accounts for stretching effect have been used. • Influences of geometrical parameters, hygrothermal conditions, and different material parameters are explored. Halpin-Tsai and extended rule of mixture (ERM) schemes are used to evaluate the effective material properties of composite face sheets of a micro-scaled sandwich rectangular plate, to assess its thermo-elastic buckling behavior, in the current paper. For more details, it should be added that under evaluation model, which is resting on a Pasternak elastic foundation, is a honeycomb micro structure which is made of Nomex or Glass Phenolic and, to integrity, is patched with two same composite layers including graphene nanoplatelets (GNPs) dispersed through Epoxy resin. Great novelty of quasi-3D hyperbolic shear deformation theory (QHSDT) which accounts for stretching effect, virtual displacement principle, and modified couple stress theory (MCST) produced a good motivation to hire it to extract equations related to the current sandwich micro plate. Finally, variations of critical loads of thermal and mechanical buckling considered in figures and tables to examine the effect of different parameters' changes on them. As an example, based on acquired results, the sensitivity of thermo-mechanical critical buckling loads to the internal aspect ratio of honeycomb core ϕ 0 and force intensity distributions is proved where force intensity enhancement is caused critical buckling load reduction. [ABSTRACT FROM AUTHOR]

In this study, novel honeycomb structures with twisted feature were designed and manufactured by laser powder bed fusion (LPBF). The manufacturability, microstructure evolution of LPBFed honeycomb components with twisted feature were studied. The influence of twist angle on the compressive behavior of components was experimentally investigated and the underlying mechanism was revealed using FE simulation. Results revealed that the material relative density of LPBFed components was reduced with the increase of twist angle, caused by the enlarging overhanging area. Different cooling rate of melt pool at different parts along the building direction resulted in different microstructures. The twist angle significantly affected the compressive behaviors of honeycomb structures. When the cell number along each side was 3, the honeycomb structure with 30° twist angle exhibited the most uniform stress distribution under compression, leading to the highest specific compressive strength and energy absorption ability. The influence of cell number and wall thickness on compressive properties of honeycomb structures with 30° twist angle were investigated through finite element simulation, and results revealed that the structure with 0.75 mm wall thickness and 3 unit cells along each side showed the highest specific energy absorption ability. • Bio-inspired honeycomb structures with twist feature were designed and made by LPBF. • The effect of twist angle on microstructures of LPBFed components was studied. • The compression behaviors of components with different twist angle were studied. • FE simulation was used to study stress distributions of structures under compression. [ABSTRACT FROM AUTHOR]

The processing of high-precision aerospace parts requires not only ultra-precision machine tools, but also high-efficiency processing. However, in order to realize high-efficiency processing, besides optimizing the system and process parameters, some subversive research can also be done on the machine tool structure. In this paper, the lightweight research is mainly carried out on the structure of machine tool worktable. The traditional workbench is very "heavy" and "slowness". If the traditional workbench is subverted and reformed to reduce the weight, the processing efficiency will be improved qualitatively. Therefore, this paper studies the lightweight worktable of CFRP (carbon fiber reinforced polymer) in combination with the biological "honeycomb" shape. At first, the tensile, bending, compressive and laminar shear analysis of CFRP were carried out, and the comprehensive parameters were obtained. Simultaneously, the theoretical research and the honeycomb structure simulation and verification of CFRP worktable are carried out. The results show that the HACT (honeycomb arrangement of circular tubes) is 18.51% better than the SACT (straight arrangement of circular tubes) and 45.05% better than the OW (original worktable) by comparing and analyzing the weight of the three modes (HACT, SACT and OW). The actual weight of bionic honeycomb lightweight worktable is 1100 kg, while the simulation result is 1080.25 kg, with an error of 1.8%. Meanwhile, it is analyzed that the original workbench weight of the five-axis machining center is 2023 kg, while the simulation result is 1998.6 kg, with an error of 1.2%. The lightweight degree is reduced by 45.05%. However, the actual lightweight degree has been reduced by 45.63%. The error between simulation and actual is less than 1.3%. This kind of structural transformation has brought forward cutting-edge innovations to the machine tool processing industry. It provides a reference scheme for related enterprises in the future equipment renovation. [ABSTRACT FROM AUTHOR]

The development of asymmetric supercapacitors with good cycle stability and high energy density is becoming increasingly a research focus of energy storage systems. Herein, this work has reported a novel method to prepare CuCo 2 S 4 /Co-MOF (metal-organic framework) electrode materials. The electrochemical properties of materials are studied by changing the electrodeposition temperature. CuCo 2 S 4 -45, CuCo 2 S 4 /Co-MOF obtained at an electrodeposition temperature of 45 °C, has a microstructure of a multi-layer sheet-like two-dimensional ultra-thin honeycomb, which can shorten the diffusion path between ions/electrons. In addition, the specific capacitance of CuCo 2 S 4 -45 can reach 2879 F g−1 at 1 A g−1 as well as the capacity retention rate is 80.3% (2312 F g−1 at 20 A g−1). Asymmetric supercapacitor CuCo 2 S 4 -45//AC using activated carbon (AC) has excellent cycle stability (maintains 82.02% after 10,000 cycles), the energy density of 63.6 W h kg−1 at power density of 700 W kg−1. The results show that the material has great practical value. • Designed synthesis of copper-cobalt-sulfur electrode materials. • The CuCo 2 S 4 /CO-MOF has a 2D multilayer ultra-thin honeycomb structure. • The electrode materials exhibited high electrochemical performance with brilliant cyclicability. [ABSTRACT FROM AUTHOR]

Single-phase polycrystalline Li 2 PdO 3 has been synthesized at 640 ̊C in oxygen for the first time under ambient pressure. X-ray and neutron diffraction analyses show that the sample possesses a monoclinic layered structure belonging to the C 2/ m space group. Rietveld refinements of neutron powder diffraction data indicate ~10% Li–Pd site exchange and DIFFaX modelling manifest ~2% stacking faults present within LiPd 2 layers. A band gap of ~2.23 eV was calculated for the golden Li 2 PdO 3 using absorbance measurements. Thermogravimetric analysis of the sample shows that Li 2 PdO 3 is stable up to 730 ̊C under oxygen. A Curie tail is observed at low temperature magnetic measurements (T < 50K), yielding an effective moment of 0.038 μ B, possibly due to spin ½ impurities. • Single phase Li2PdO3 was synthesized and its crystal structure was elucidated. • Stacking Fault modeling yielded a density of ~2% occurring perpendicular to LiPd 2 layers. • A band gap of ~2.23 eV was calculated for Li 2 PdO 3 using UV–Vis absorbance. • Thermogravimetric analysis showed that Li 2 PdO 3 is stable up to 730 ̊C under oxygen. • Temperature <50 K, a Curie tail is yielded an effective moment of 0.038 μ B. [ABSTRACT FROM AUTHOR]

An analytical model is developed to investigate the in-plane mechanical properties of a thin-walled honeycomb structure. Nonlinear constitutive relations of honeycombs are presented based on in-plane large deformation analysis of a beam; elastic and plastic behaviors are both considered. These relations reflect the dependence of the equivalent stress, equivalent Young's modulus, and equivalent Poisson's ratio on deformation. Numerical simulation results indicate the effectiveness of the proposed method. Paramatric study is then conducted to investigate the effects of structural and material parameters on the honeycomb structure which is valuable for honeycomb structure design. • A theoretical model is developed to investigate the elastic-plastic behavior of a thin-walled honeycomb structure. • In-plane tension and compression analyses were carried out to reveal nonlinear constitutive relations of beams. • The modified factors are presented which depend on the shape and deformation of the honeycomb. • The proposed model can achieve a range of Poisson's ratio and Young's modulus values by parameters design. [ABSTRACT FROM AUTHOR]

Single-phase polycrystalline Li 2 PdO 3 has been synthesized at 640 ̊C in oxygen for the first time under ambient pressure. X-ray and neutron diffraction analyses show that the sample possesses a monoclinic layered structure belonging to the C 2/ m space group. Rietveld refinements of neutron powder diffraction data indicate ~10% Li–Pd site exchange and DIFFaX modelling manifest ~2% stacking faults present within LiPd 2 layers. A band gap of ~2.23 eV was calculated for the golden Li 2 PdO 3 using absorbance measurements. Thermogravimetric analysis of the sample shows that Li 2 PdO 3 is stable up to 730 ̊C under oxygen. A Curie tail is observed at low temperature magnetic measurements (T < 50K), yielding an effective moment of 0.038 μ B, possibly due to spin ½ impurities. • Single phase Li2PdO3 was synthesized and its crystal structure was elucidated. • Stacking Fault modeling yielded a density of ~2% occurring perpendicular to LiPd 2 layers. • A band gap of ~2.23 eV was calculated for Li 2 PdO 3 using UV–Vis absorbance. • Thermogravimetric analysis showed that Li 2 PdO 3 is stable up to 730 ̊C under oxygen. • Temperature <50 K, a Curie tail is yielded an effective moment of 0.038 μ B. [ABSTRACT FROM AUTHOR]

Here, we show a facile and one-step electrospinning strategy to fabricate multi-region scaffolds that display two main fibrillar microstructure arrays: honeycomb-like (HC) and randomly-oriented (RO), which are joined by an interface that aims to facilitate a smooth physical transition between them. Relevant design parameters including macropore size, fiber diameter, piezoelectric and mechanical properties were investigated. Our results show that polycaprolactone (PCL)-based scaffolds exhibited macropores in the HC and interface regions that could be tailored (from 867 ± 74 to 424 ± 27 μm and from 101 ± 10 to 80 ± 10, respectively) by increasing the electrospun polymer volume, while their fiber diameter distribution was not altered in a significant manner. Moreover, the local mechanical properties of these scaffolds changed in a discreet fashion according to each region's geometry, ensuring physical properties gradation from the RO to the HC zones. The versatility of this scaffold fabrication method was extended to the use of polyvinylidine fluoride (PVDF): while the macrostructural and mechanical properties were preserved, different fiber size distribution between the RO (353 ± 53 nm) and HC (251 ± 37 nm) regions as well as dissimilar fiber orientation were found, correlating with a variation in the piezoelectricity (β-phase fraction) within the scaffold. This fabrication technique could represent another alternative to engineer biocompatible multi-tissue systems with tunable structure and mechanics. Image 1 • A macroporous interface was found beneficial for moderate mechanical changes. • Different macropore size and fiber alignment in the same multi-region material. • Honeycomb-like structures favored the appearance of β-phase in PVDF materials. [ABSTRACT FROM AUTHOR]

Graphene oxide has been proven to be a promising anti-penetrant shield for Mg alloys against their over-rapid biodegradation, but the weak interfacial bonding between graphene oxide and Mg alloy is the main obstacle for effective protection. In this study, magnesium oxide (MgO) nanoparticles are coated on reduced graphene oxide (RGO) surface and then introduced in AZ61 alloy by laser melting, expecting to strengthen the interfacial bonding between Mg matrix and RGO. The results reveal that MgO acts as an interfacial bridge between Mg matrix and RGO and constructs nanoscale-contact and distortion areas with RGO. Moreover, MgO and α-Mg form a semi-coherent interfacial structure, in which an orientation relationship of MgO (‾200)//α-Mg (‾110‾2) and a small planar disregistry of 7.5% are detected. These interfacial characteristics indicate strong bonding at both the RGO/MgO and MgO/α-Mg interfaces, which thereby strengthens the protective capability of RGO. Compared with AZ61-RGO composite and AZ61 alloy, the AZ61-RGO/MgO composite present 13.3% and 34.0% decreases in corrosion rate, respectively. Meanwhile, the compressive strength and hardness of AZ61 alloy are also enhanced owing to the strengthened interfacial bonding. These findings demonstrate that the RGO/Mg interfacial strengthening is a promising candidate for improving the degradation behavior of Mg alloys. Unlabelled Image • A honeycomb structure with α-Mg grains encapsulated by RGO/MgO formed. • A semi-coherent structure formed at the interface of MgO/α-Mg. • Nanoscale-contact interfaces and distortion area formed at the RGO/MgO interface. • Stable honeycomb structure effectively acquiring a higher corrosion resistance the degradation of Mg alloys. [ABSTRACT FROM AUTHOR]

• 3D honeycomb-like MoSe 2 /rGO is designed and prepared as excellent Na+ stroage materials. • The honeycomb structure facilitates the fast Na+ transfer while buffer the volume expansion. • MoSe 2 /rGO exhibits outstanding cycle stability and excellent rate capacility. Transition metal dichalcogenides (TMDs) caused widespread concern because of their possess graphite-like two-dimensional structure, which allows Na+ reversible de-intercalation between the interlayers and contributes high theoretical capacity. However, the poor conductivity and structural instability greatly limited their application to sodium ion batteries (SIBs). Herein, three-dimensional (3D) honeycomb MoSe 2 /rGO nanocomposites with outstanding sodium ion storage performance were prepared. The MoSe 2 /rGO combined the advantages of MoSe 2 and rGO. The typical layered structure of MoSe 2 provide Na+ diffusion pathways and sufficient active sites, while the rGO increase conductivity and alleviate structural change during Na+ insertion/extraction process. The stable discharge capacity of MoSe 2 /rGO reaches 300 mAh g−1 at 0.1 A g−1 and retains 247 mAh g−1 after 100 times. It retains a high capacity of 214.7 mAh g−1 at 1 A g−1 and shows outstanding rate capability. The MoSe 2 /rGO//AC hybrid sodium-ion capacitors (HSIC) achieves a high capacitance of 56.7 F g−1 at 0.1 A g−1, it exhibits an energy density of 87.7 W kg−1 at a power density of 208.8 W h kg−1 and retains 50.5 W h kg−1 when it increases to 1051.4 W kg−1. The article brings up a novel opinion for designing porous TMDs based composites as ideal energy storage materials. [ABSTRACT FROM AUTHOR]

This work reports on a study regarding the plasmonic properties of a honeycomb-like structure that is formed by silver and gold nanoparticles. A honeycomb structure is proposed, and its plasmonic characteristics under the irradiation of a plane-wave light are numerically calculated, with several parameters being varied, including the radius of the nanoparticles, the separation between adjacent nanoparticles, and the polarization of the incident light. In the honeycomb, highly localized electric fields created by the oscillation of surface electrons are observed, and the associated electromagnetic hot spots are revealed in the vicinity of the noble metals. The results demonstrate that localized electric fields can be generated in the honeycomb-like structure, due to the plasmonic coupling between the metallic nanoparticles, and the hot spots can be adjusted by varying the values of the nanoparticles' radius, the separation, as well as the incident light's polarization. The plasmonic characteristics of the metal–nanoparticle honeycomb structure revealed in this study may be useful in the designs of plasmonic devices that utilizes localized, intensive electromagnetic hot spots. • Plasmonic properties of a honeycomb formed by metallic nanoparticles are studied. • Highly localized electric fields, and electromagnetic hot spots are observed. • Hot spots can be adjusted by varying nanoparticles' radius and separation. • Polarization of incident light can also affect hot spots' characteristics. [ABSTRACT FROM AUTHOR]