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Two different Tuned liquid dampers (TLDs) were installed on the floors of a three-floor structure. The TLD natural frequencies were tuned to the first two resonance frequencies of the structure, and its base was subjected to harmonic excitation. The excitation frequency of the sweep tests ranged from 0.8 to 3.2 Hz, and the mass ratio for all the simulations was constant and equalled 2%. The FVM/FEM method was used to solve the fluid-structure coupling, and the maximum displacement of the three floors were obtained. The dissipated energy by damping force was used to study the coupling mechanism of TLD and multilayer structure. Findings indicated that the scheme of the multiple-TLD design was stable and effective, which ensured that the structure-TLD system under the same mass ratio had no local adverse effects. The proportion of positive work time of tank hydrodynamic force is the intuitive embodiment of TLD damping performance. The frequency doubling effect generated by the sloshing nonlinearity in TLD has been confirmed for use in the vibration control of higher-order modes of structures. On the premise of constant mass ratio, it is suggested to adopt a multi-TLD damping system, in which each damper is installed at the height of the maximum displacement of each structural mode. [ABSTRACT FROM AUTHOR]

In this study, Al-doped ZnO/Ag/WO3 (AZO/Ag/WO3)multilayer films were fabricated on polyethylene terephthalate (PET) substrates using the magnetron sputtering technique. A two-step magnetron sputtering process was employed to deposit WO3, effectively preventing insulation in the AZO/Ag/WO3 multilayer film caused by silver oxidation. The optical properties of the AZO/Ag/WO3 multilayer films can be adjusted by varying the thickness of AZO and WO3 layers. The optimal AZO/Ag/WO3 multilayer film demonstrates a maximum figure-of-merit of 1.74 × 10− 2 Ω−1, with an average visible light transmittance of 81.1% and a sheet resistance of 7.04 Ω sq− 1. When applied in transparent flexible heaters, the AZO/Ag/WO3 multilayer films exhibit rapid thermal response, stable and controllable heating performance at low operating voltage, indicating exceptional thermal properties and high conductivity. The two-step magnetron sputtering deposition of external oxide layers to prevent the oxidation of silver is cost-effective and can be utilized to create high-performance oxide/metal/oxide transparent electrodes. [ABSTRACT FROM AUTHOR]

Nanochitin was developed to effectively utilize crab shells, a food waste product, and there is ongoing research into its applications. Short nanowhiskers were produced by sonicating partially deacetylated nanochitin in water, resulting in a significant decrease in viscosity due to reduced entanglement of the nanowhiskers. These nanowhiskers self-assembled into a multilayered film through an evaporation technique. The macro- and nanoscale structures within the film manipulate light, producing vibrant and durable structural colors. The dried cast film exhibited green and purple stripes extending from the center to the edge formed by interference effects from the multilayer structure and thickness variations. Preserving structural colors requires maintaining a low ionic strength in the dispersion, as a higher ionic strength reduces electrostatic repulsion between nanofibers, increasing viscosity and potentially leading to the fading of color. This material's sensitivity to environmental changes, combined with chitin's biocompatibility, makes it well-suited for food sensors, wherein it can visually indicate freshness or spoilage. Furthermore, chitin's stable and non-toxic properties offer a sustainable alternative to traditional dyes in cosmetics, delivering vivid and long-lasting color. [ABSTRACT FROM AUTHOR]

Ultrasound imaging for bone is a difficult task in the field of medical ultrasound. Compared with other phase array techniques, the synthetic aperture (SA) has a better lateral resolution but a limited imaging depth due to the limited ultrasonic energy emitted by the single emitter in each transmission. In contrast, the virtual source (VS) synthetic aperture allows a simultaneous multi-element emission and could provide a higher ultrasonic incident energy in each transmission. Therefore, the VS might achieve a high imaging quality at a deeper depth for bone imaging than the traditional SA. In this study, we proposed the virtual source phase shift migration (VS-PSM) method to achieve ultrasonic imaging of the deeper bone defect featured in the multilayer structure. The proposed VS-PSM method was validated using standard soft tissue phantom and printed bone phantom with artificial defects. The image quality was evaluated in terms of contrast-to-noise ratios (CNR) and amplitudes of scatters and defects at different imaging depths. The results showed that the VS-PSM method could achieve a high imaging quality of the soft tissues with a significant improvement in the scattering amplitude and without a significant sacrifice of the lateral and axial resolution. The PSM was superior to the DAS in suppressing the background noise in the images. Compared with the traditional SA-PSM, the VS-PSM method could image deeper bone defects at different ultrasonic frequencies, with an average improvement of 50% in CNR. In conclusion, this study demonstrated that the proposed VS-PSM method could image deeper bone defects and might help the diagnosis of bone disease using ultrasonic imaging. [ABSTRACT FROM AUTHOR]

Flexible pressure sensors based on paper have attracted considerable attention owing to their good performance, low cost, and environmental friendliness. However, effectively expanding the detection range of paper-based sensors with high sensitivities is still a challenge. Herein, we present a paper-based resistive pressure sensor with a sandwich structure consisting of two electrodes and three sensing layers. The silver nanowires were dispersed deposited on a filter paper substrate using the vacuum filtration coating method to prepare the electrode. And the sensing layer was fabricated by coating carbon nanotubes onto a mulberry paper substrate. Waterborne polyurethane was introduced in the process of preparing the sensing layers to enhance the strength of the interface between the carbon nanotubes and the mulberry paper substrate. Therefore, the designed sensor exhibits a good sensing performance by virtue of the rational structure design and proper material selection. Specifically, the rough surfaces of the sensing layers, porous conductive network of silver nanowires on the electrodes, and the multilayer stacked structure of the sensor collaboratively increase the change in the surface contact area under a pressure load, which improves the sensitivity and extends the sensing range simultaneously. Consequently, the designed sensor exhibits a high sensitivity (up to 6.26 kPa−1), wide measurement range (1000 kPa), low detection limit (~1 Pa), and excellent stability (1000 cycles). All these advantages guarantee that the sensor has potential for applications in smart wearable devices and the Internet of Things. [ABSTRACT FROM AUTHOR]

Flexible strain sensors capable of acquiring tiny mechanical signals and attaching to various irregular surfaces are becoming prevalent in physiological measurement, soft robotics, and human‐machine interaction. However, the advancement of flexible strain sensors is substantially impeded by the intrinsic compromise between sensitivity and the range of detectable signals. Inspired by the multilayer structure of nacre in nature, a carbon nanotubes (CNTs)/graphene (GR)/graphene (GR)/thermoplastic polyurethane (TPU) mat (CGGTM) is prepared by electrospinning and high‐pressure spraying technology. By designing a multilayer structure with mutually non‐interfering conductive networks, the resulting CGGTM possesses a low detection limit (0.05% strain), high sensitivity (gauge factor, GF > 152537), large detection range (up to 364% strain), fast response/recovery time (80 ms/100 ms), and excellent cyclic durability (up to 1000 cycles). Furthermore, the CGGTM also exhibits satisfactory triboelectric performances when assembled into a triboelectric nanogenerator (TENG, 3 × 3 cm2), including high triboelectric output (open‐circuit voltage Voc = 135.4 V, short‐circuit current Isc = 1.25 µA) and power density (88 mW m−2), enabling reliable power supply, self‐powered sensing, and pulse monitoring capability. Finally, CGGTM is successfully applied to the collection of biological signals and multi‐gesture motion recognition assisted by machine learning algorithms, which holds promise for intelligent interaction with gestures in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] A composite material with a high potential for absorbing electromagnetic waves (EMW) was obtained by selecting poly (vinylidene fluoride) (PVDF) as the matrix, MXene as the conductive filler, and cobalt ferrite (CoFe 2 O 4) as the magnetic filler. A layer-by-layer assembly strategy involved hot pressing and sequential blade coating, followed by vapor-induced phase separation, was used to implement the preparation of PVDF/MXene/CoFe 2 O 4 (PMC) composites. The process facilitates the formation of a well-organized multilayer porous framework, providing a gradient of positive conductivity, negative magnetism, and porosity within the composites. Incorporating distinct multilayer, porous, and gradient structures into a single composite led to exceptional impedance matching (Z), with an area percentage of up to 8.4 % in the optimal range of 0.8 to 1.2. Furthermore, the multiple interfaces formed by the various components, multilayer structure, and porous configuration significantly enhanced the EMW attenuation capability, with the attenuation constant reaching as high as 274. Consequently, the PMC composite demonstrated outstanding performance with a minimal reflection loss (RL min) of −56.5 dB, a specific RL min of 23.5 dB/mm, and the broadest effective absorption bandwidth of 3.2 GHz. The combination of the competitive EMW absorption capability, low density, flexibility, adequate tensile strength, and amphiphilic Janus surface may significantly broaden the application scenarios of PMC composites. [ABSTRACT FROM AUTHOR]

Zirconate-based dielectric ceramics are potential materials for base metal electrode multilayer ceramic capacitors (BME-MLCCs) due to their exceptional chemical and thermal stability, as well as excellent dielectric properties. In this work, (Sr0.7Ca0.3)1.02(Zr0.95−xTi0.05Mnx)O3+δ (SCZTM, 0 ≤ x ≤ 0.05) ceramics with two coexisting phases were prepared using a solid-state reaction method in a reducing atmosphere. This study investigates the impact of Mn doping on sintering temperature, microstructure, and electrical properties of SCZTM ceramics. Mn doping can reduce the sintering temperature from 1450 to 1300 °C. The impact of Mn doping on the structure and phonon vibration is minimal, resulting in a negligible effect on the intrinsic loss. The valence states of Mn ions and defects were characterized by X-ray photoelectron spectroscopy (XPS) and thermally stimulated depolarization current (TSDC) analysis. The results demonstrate the significant role of Mn doping in nonintrinsic loss. Due to the decrease in the concentration of oxygen vacancies (VO⋅⋅), SCZTM (x = 0.01) ceramics exhibit attractive properties: resistivity (ρ) = 8.93×1014 Ω·cm, dielectric constant (εr) = 36.16, dielectric loss (tanδ) = 2.43×10–4, temperature dependence of dielectric constant (τε) = 15.44 ppm/°C (@−55–200 °C, 1 MHz), Q×f = 30,257 GHz (@6.12 GHz), and temperature coefficient of resonant frequency (τf) = –9.9 ppm/°C. SCZTM (x = 0.01) ceramic powders were used to successfully fabricate Ni-based multilayer ceramic capacitors (MLCCs) with a high insulation resistance of IR ≥ 39.6 TΩ, an ultralow dielectric loss of tanδ = 0.2×10–4, and a wide operating temperature range (temperature coefficient of capacitance (Tcc) = 10.88 ppm/°C, @−55–200 °C, 1 MHz). SCZTM ceramics exhibit properties that make them suitable for use as BME-MLCC materials with potential market applications.

Introduction. Numerous researchers of the reliability of building structures pay attention to hardness, an important characteristic of the structural material. It is determined by indentation — pressing the tip of the tool into the surface. The advantages of dynamic indentation methods and the distribution of stress intensity on the surface and inside the sample are investigated. However, the condition of layered materials on impact has been poorly studied. The objective of the presented work is to consider indentation for a two-layer sample and determine the sensitivity of the top layer to the strength of the substrate. This will allow us to identify significant characteristics of the strength properties of homogeneous and heterogeneous structures.Materials and Methods. An elastoplastic model of material behavior and a shock indentation scheme were used, which took into account the masses of the indenter and the striker coupled by linear springs. The surface of the indenter was conical, the opening angle was 120°. The impact was simulated in the MATLAB system. Finite element model in Ansys APDL was used to verify the data and analyze the results of the experiment. Traditional models of elasticity theory were used for calculations. The behavior of the material in the zone of plastic deformation was described using the options of multilinear isotropic hardening and the von Mises plasticity criterion.Results. The results of comparing three versions of varying the level of yield strength in the bottom layer are presented: when the yield strength in the bottom layer is half as high as the top one, equal to it, and twice as high. Displacements at different observation points for samples with a top layer of 2 mm and 1 mm were analyzed. In the first case, under horizontal shear, the displacement indices inside the sample did not change if the yield strength level was twice lower or higher than in the top one. If these indicators were equal, the difference became noticeable. In the second case (layer 1 mm), the difference in displacement was visible at all observation points. Thus, it can be reasonably concluded that a structure with a smaller top layer is more sensitive to impact. In the course of the research, it became known that vibrations associated with the transition to the plasticity zone occurred in the 2 mm zone, and elastic damping vibrations occurred below this zone. We solved the classification problem for the top layer of the material with changing characteristics of the base. The indicator for comparison was the Brinell hardness (HB) in the range of 200–600. The results were processed using a neural network and visualized in the form of graphs. The accuracy of its calculations was 98%.Discussion and Conclusion. To determine the strength properties of homogeneous structures, it is sufficient to characterize the speed of displacement inside the sample. For an inhomogeneous structure, additional parameters should be introduced — displacements on the surface and inside the sample at fixed observation points. An integrated approach to determining the strength properties of an inhomogeneous structure improves the accuracy of calculations, and the use of neural networks increases their speed.

In the process of grain storage, the use of low-temperature grain storage technology can effectively reduce grain losses during storage and ensure grain quality, which is of great significance for maintaining a stable grain supply. Radiative cooling materials, as a new energy-free cooling technology, achieve cooling by radiating heat in the form of electromagnetic waves into outer space. This approach can address issues associated with traditional cooling methods, such as high energy consumption and high chemical oxygen demand (COD) emissions, offering a green and environmentally friendly new approach to low-temperature grain storage. This paper explained the working principle of polymer-based radiative cooling materials and systematically introduced the composition and selection criteria of polymer-based radiative cooling systems. It also categorized and summarized polymer-based radiative cooling materials according to their structural characteristics. The existing problems with different structured radiative cooling materials, as well as future research directions, were also analyzed. This provides a certain research framework for applying radiative cooling materials to grain storage facilities to achieve low-temperature grain storage.

The hot-rolled microstructure of medium Mn steel has coarse grains and severe elemental segregation, resulting in low strength and plasticity. Constructing a multiphase structure, refining the microstructure, and regulating elemental segregation enhance the mechanical properties. In this study, liquid nitrogen treatment created a layered distribution of austenite and martensite. Warm rolling was then used to reduce layer thickness and refine grain structure. After liquid nitrogen and warm rolling treatments, the strength and plasticity of medium Mn steel increased to 1270 MPa and 23.3%, respectively, far exceeding the hot-rolled state (724 MPa, 12.8%). Warm rolling also triggers austenite reverted transformation (ART) and introduces high-density dislocations, further improving austenite stability. This strengthening effect is higher than that from intercritical annealing alone. Improved austenite stability delays the transformation induced plasticity (TRIP) effect, preventing brittle fracture and enhancing deformation coordination between layers, significantly increasing the plastic deformation capacity of medium Mn steel.

Polymer dispersed liquid crystals (PDLC) and polymer stabilised cholesteric liquid crystals (PSCLC) are an indispensable class of electrically switchable materials, which have been widely applied in the fabrication of efficient and systematic smart windows. And doping nanoparticles in PDLC films can greatly improve their properties. In this study, PDLC films doped with zirconia nanoparticles were prepared by polymerisation-induced phase separation (PIPS) method, PSCLC films with nematic liquid crystals as the main part (reflecting wavelengths in the range of 400–600 nm) were prepared by UV curing method, and a novel optical switch was developed by combining these two liquid crystal films. The optimal bilayer sample was developed through a comparative analysis of properties among samples with varying formulations for each liquid crystal layer. This study represents a novel advancement in PSCLC and nanoparticle-doped PDLC bilayer structures, showcasing fully actuatable properties in the visible wavelength range. These structures exhibit excellent electro-optical properties and demonstrate stable, sustainable performance that can be regenerated. The findings underscore the potential of PDLC and PSCLC for applications in smart curtains and flexible materials, opening up new avenues for innovative technological applications. [ABSTRACT FROM AUTHOR]

The development of flexible piezoresistive sensors has increasingly attracted widespread attention due to their various potential applications in wearable devices, human–machine interfaces, and health monitoring systems. Developing high‐performance sensors that can accurately monitor movement and human health monitoring is very necessary. This study uses silver nanoparticles, MXene, and polypyrrole to prepare conductive fabrics based on various fabrics through layer‐by‐layer encapsulation. Finally, conductive fabrics with different layers were encapsulated to prepare a multilayer fiber sensor. Next, the series piezoresistive performance of sensors made of different fabric materials and sensors with different layers were tested. The experimental results show that the sensor prepared has the best performance when the selected fabric material is mulberry silk and the number of layers of the fabric is five. After testing, the sensitivity of the sensor is 4.9029 at low strain and 0.7901 at high strain. Moreover, it exhibits good stability during 1600 compression‐release cycles and temperatures range from −20 to 60°C. The designed sensor performs well in motion and human physiological signal monitoring. This study provides new ideas and references for the design and research of multilayer fiber sensors. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Cereals, Oils & Foods is the property of Science & Technology of Cereals, Oils & Foods Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As porous materials, textiles have been widely used in noise reduction and control engineering due to the advantages of lightweight and easy processing. In this work, the effects of structural factors and physical properties of woven jute fabrics on sound absorption were investigated. Woven jute fabrics with different warp and weft density, thickness, areal weight, and bulk density are employed for acoustical impedance tube measurement, and the warp and weft flexural rigidity, and air permeability of woven jute fabric were measured. The relationship between structural characteristics and sound absorption properties was studied, which has provided good reference for the design of fabric texture. Furthermore, multilayered structure was also constructed by facile plying-up method, followed by the evaluation on the effects of various layering configuration, and then for improved sound absorption. This investigation has mainly focused on woven factors and physical properties, which is benefit to the fabrication of woven jute fabrics with optimal structural details for enhanced sound absorption. [ABSTRACT FROM AUTHOR]

In this paper, the authors present the ability to control a white organic light-emitting diode's (WOLED) color temperature and radiation intensity. The architecture is proposed and a WOLED structure is developed based on the host-guest system. The function of the guest component is performed by a red ambipolar fluorescent emitter based on quinoxaline (CTQTC), and the host material is mCP (donor component of the exciplex mCBP: PO-T2T). Electroluminescence recombination occurred on the blue exciplex/electroplex mCP-PO-T2T and the guest CTQTC emitter. The emission intensity of the CTQTC emitter does not depend on the applied voltage, unlike the other bands of the emission spectra. The additional WOLED emission maximum is in the spectrum's green region due to the electrometric nature of the TAPC hole transport layer. The color temperature of the developed WOLED varied from 3000 to 4000 K in the applied voltage range from 8 to 14V, corresponding to warm and cold white color. The device also exhibits a maximum brightness of 2968 cd/m2 and a maximum external quantum efficiency of 4.07%. [ABSTRACT FROM AUTHOR]

[Display omitted] Compared with layered materials such as graphite and transition metal disulfide compounds with highly anisotropic in-plane covalent bonds, it is inherently more challenging to obtain independent metallic two-dimensional films with atomic thickness. In this study, PtNi layered metallene nanobowls (LMBs) with multilayer atomic-scale nanosheets and bowl-like structures have been synthesized in one step using structural and electronic effects. The material has the advantage of catalyzing pH-universal hydrogen evolution reaction (HER). Compared with Pt/C, PtNi LMBs exhibited excellent HER activity and stability under all pH conditions. The overpotentials of 10 mA cm−2 at 0.5 M H 2 SO 4 , 1.0 M phosphate buffer and 1.0 M KOH were 14.8, 20.3, and 34.0 mV, respectively. Under acidic, neutral and alkaline conditions, the HER Faraday efficiencies reach 98.97%, 98.85%, and 99.04%, respectively. This study provides an example for the preparation of unique multilayer nanobowls, and also provides a basic research platform for the development of special HER materials. [ABSTRACT FROM AUTHOR]

Near-field radiative heat transfer (NFRHT) between multilayer graphene/hBN heterostructures has been demonstrated to exceed the blackbody limit due to the coupling mechanism of surface plasmon polaritons and hyperbolic phonon polaritons, opening the door to applications in thermal management, thermophotovoltaics, and nanoscale metrology. Recent studies have shown that adding vacuum layers within multilayer structures can effectively promote surface modes and thus enhance NFRHT. However, the influence of vacuum layers on NFRHT between multilayer graphene/hBN heterostructures has not been investigated. Moreover, the influence of vacuum layers on coupled resonance modes excited in multilayer structures is worth discussing. In this work, we study the NFRHT based on multilayer graphene/vacuum/hBN/vacuum structures. The results show that as the gap distance increases from 20 nm to 100 nm, the NFRHT of three-cell and six-cell configurations is enhanced, while that of unit-cell configuration is suppressed. The potential mechanism can be identified as the excitation of surface plasmon-phonon polaritons (SPPPs) and hyperbolic plasmon-phonon polaritons (HPPPs) in multilayer structures. The enhancement factor of the six-cell configurations is up to 4.82 when the gap distance is 80 nm. Moreover, the influences of the chemical potential of graphene and the layer thickness on the NFRHT are discussed. The interesting results in this work indicate the perspectives for future near-field research involving coupling of SPPPs and HPPPs, and shed new light on high-performance devices introducing vacuum layers based on near-field radiative heat transfer. [ABSTRACT FROM AUTHOR]

Theoretically calculated IR absorption spectra of Ti/SiO2/Si3N4/n+-Si structures with an island surface layer were used to show that the absorption maximum broadened and shifted to longer wavelength as the n+-Si island size increased with a constant period of their placement on the surface. This peak was probably associated with excitation of plasmon oscillations in the surface island layer. A structure with an island size of 3 μm and a period of 6 μm was shown to absorb ~99% of the incident radiation at a wavelength practically equal to the period (6.2 μm). Other absorption bands at ~4 μm and 9.0–9.5 μm arose regardless of the island size and were associated with absorption in the SiO2 layer. A layer of undoped silicon of thickness up to 200 nm located between the Ti substrate and SiO2 layer slightly reduced the intensity and half-width of the plasmon absorption maximum. [ABSTRACT FROM AUTHOR]

This paper presents the extension of the monolayer snow model of a semi-distributed hydrological model (HYDROTEL) to a multilayer model that considers snow to be a combination of ice and air, while accounting for freezing rain. For two stations in Yukon and one station in northern Quebec, Canada, the multilayer model achieves high performances during calibration periods yet similar to the those of the monolayer model, with KGEs of up to 0.9. However, it increases the KGE values by up to 0.2 during the validation periods. The multilayer model provides more accurate estimations of maximum SWE and total spring snowmelt dates. This is due to its increased sensitivity to thermal atmospheric conditions. Although the multilayer model improves the estimation of snow heights overall, it exhibits excessive snow densities during spring snowmelt. Future research should aim to refine the representation of snow densities to enhance the accuracy of the multilayer model. Nevertheless, this model has the potential to improve the simulation of spring snowmelt, addressing a common limitation of the monolayer model. [ABSTRACT FROM AUTHOR]

Chemical compatibility of water‐soluble azo‐dye photoalignment materials opens up new possibilities of thin‐film optical devices fabrication with advanced characteristics combining several polymerizable liquid crystal layers into multilayer structures of broadband quarter or half wave retarders. However when the azodye photoalignment layer is placed in‐between two layers of polymerizable liquid crystal significant increase of dye absorption is observed. Analysis of this 'Absorption Problem' concludes azodye inter‐layer field is the cause of polarization and cis‐trans equilibrium change. New water‐soluble azo‐dye photoalignment material AmA‐2522 is suggested as perspective problem solution. [ABSTRACT FROM AUTHOR]

The dissimilar metal welding joint is connected by the metallurgical bond of intermetallic compounds at the interface, which easily causes stress concentration at the interface and cracks continuously along the interface, resulting in low reliability in impact environments. A novel multi-layer plug and bolt connection for TC4/7A52 dissimilar metal butt joints is proposed in this manuscript and analyzes the influence mechanism of the structural design on impact toughness. The impact toughness of the Ti/Al composite butt joint is 30.3 J/cm2, which is 2.6 times that of the 7A52 BM. The layered toughening design significantly reduces stress concentrations for the butt joint at impact for the Ti/Al composite butt joint. Upon impact, the Ti/Al composite butt joint does not fracture continuously at the V-notch and exhibits significant macroscopic plastic deformation. For the microstructure of each TC4 and 7A52 layer in the impact fracture, more intragranular slip systems are activated and show a higher dislocation density. Therefore, this structural design can enable dissimilar metals to absorb more impact energy during the impact process.

The presence of the effect of thermally activated delayed fluorescence (TADF) in organic light-emitting materials (emitters), manifested in the "collecting" of triplet excitons in organic semiconductor complexes that do not contain noble metals, creates excellent prerequisites for the application of TADF materials in the technology of manufacturing organic light-emitting diodes (OLED). The significant progress in solving theoretical and technical problems, achieved in the process of development of highly efficient TADF materials, paves the way for the formation of the future of organic electronics. This review presents the analyses of the nature of the long-term fluorescence generation mechanism at the molecular level and the up-to-date strategies for designing TADF donor-acceptor materials, as well as exciplex intermolecular complexes. Special attention is focused on the analysis of TADF emitter ambipolar materials with a highly twisted, rigid molecular structure, which reveal a tendency towards the multi-channel emission mechanisms and their implementation in a variety of OLED structure architectures.

Magnetic levitation systems are known for their inherent nonlinearities and complexities, posing significant challenges to conventional control methods. This study aims to develop an advanced control strategy that addresses these challenges by utilizing type-2 fuzzy CMAC (Cerebellar Model Articulation Controller) and Elman neural networks. The motivation behind this research is to enhance the stability, accuracy, and robustness of magnetic levitation systems, which are crucial for precision applications. Our proposed hybrid approach leverages the adaptive capabilities of type-2 fuzzy logic to manage uncertainties and external disturbances, while the dynamic learning ability of the Elman neural network effectively captures the system’s behavior to provide robust feedback control. The type-2 fuzzy CMAC approximates the desired control actions, and the Elman neural network refines the control dynamics, resulting in a synergistic effect that significantly improves system performance. Experimental results demonstrate the superiority of the proposed method over traditional control techniques, highlighting improved stability and accuracy under varying conditions. This research provides a promising solution for the control of complex, nonlinear magnetic levitation systems and suggests potential for broader applications in advanced control engineering.

To obtain high-frequency SAW devices, the interdigital transducer electrodes are prepared narrower and the electrode spacing is smaller, which leads to higher cost and lower reliability of high-frequency SAW devices. In this paper, two other interdigital electrode parallel layout structures are designed based on the traditional IDT flat layer layout structure, and the influence of the three different IDT electrode layout structures on the SAW device of LiNbO3/Diamond/Si multilayer structure is studied by COMSOL Multiphysics. The results show that the designed multi-layer structure SAW device can successfully excite SAW with superior performance, and the parallel layout structure of the interdigital electrode can reduce the lateral size of SAW device, which provides a new idea and direction for the miniaturization of the SAW devices.

Flexible pressure sensors based on paper have attracted considerable attention owing to their good performance, low cost, and environmental friendliness. However, effectively expanding the detection range of paper-based sensors with high sensitivities is still a challenge. Herein, we present a paper-based resistive pressure sensor with a sandwich structure consisting of two electrodes and three sensing layers. The silver nanowires were dispersed deposited on a filter paper substrate using the vacuum filtration coating method to prepare the electrode. And the sensing layer was fabricated by coating carbon nanotubes onto a mulberry paper substrate. Waterborne polyurethane was introduced in the process of preparing the sensing layers to enhance the strength of the interface between the carbon nanotubes and the mulberry paper substrate. Therefore, the designed sensor exhibits a good sensing performance by virtue of the rational structure design and proper material selection. Specifically, the rough surfaces of the sensing layers, porous conductive network of silver nanowires on the electrodes, and the multilayer stacked structure of the sensor collaboratively increase the change in the surface contact area under a pressure load, which improves the sensitivity and extends the sensing range simultaneously. Consequently, the designed sensor exhibits a high sensitivity (up to 6.26 kPa−1), wide measurement range (1000 kPa), low detection limit (~1 Pa), and excellent stability (1000 cycles). All these advantages guarantee that the sensor has potential for applications in smart wearable devices and the Internet of Things.

The harsh radiation environment of Jupiter imposes significant constraints on the shield design of spacecraft. Due to these constraints, traditional aluminum shields cannot meet the radiation shielding requirements needed for the exploration of Jupiter. In this paper, the design for a highly efficient radiation shield structure is proposed that utilizes a combination of high-Z/low-Z elements. A typical exploration orbit of Jupiter is selected, and the energetic particle radiation environment is calculated using the D&G83 model. The Geant4 toolkit is used to evaluate the shielding performance of materials, and quantitative simulations are performed to analyze the shielding efficiency of bilayer and trilayer shield structures under an areal density constraint of 4.5 g/cm2. Based on the simulations, an optimal shield structure is determined. The simulation results show that the integral electron flux with energy greater than 3 MeV is approximately three orders of magnitude greater than that of geostationary orbit with an orbit of 4000 km at the perijove and 5420000 km at the apojove, resulting in an enormous total dose effect. The optimal shield structure is a bilayer structure that comprises of a tantalum outer layer with a density of 3.5 g/cm2 and a polyethylene inner layer with a density of 1.0 g/cm2. This shield has the ability to reduce the total radiation dose to 1559 Gy per year, which is 32 % lower than that of traditional aluminum shields. Findings in this research are critical for design of radiation shields, and can be used for performing reliability analyses and predicting the lifespan of spacecraft during the development process. [ABSTRACT FROM AUTHOR]

Abstract—Since the stability of functional properties of a transparent conducting three-layer structure ZnO:Ga/Ag/ZnO:Ga is important for practical application, we studied its long-term durability and thermal stability in air environment. It has been demonstrated that after prolonged interaction with the air environment at room temperature (for ~1000 days) and further heat treatment in air at temperatures of up to 450°C (for up to 10 h), the three-layer structure retains its integrity and is characterized by a low sheet resistance Rs = 2.8 Ohm/sq at average transmittance in the visible range Tav = 82.1%. [ABSTRACT FROM AUTHOR]

The dependence of the electrical resistance of a volumetric homogeneous conductor on the area of electrical contacts has been studied by computer modeling methods. To describe this dependence, simple analytical models are proposed, which are suitable for engineering calculations. The problem of resistance of a multilayer structure with a small contact is considered and solved. [ABSTRACT FROM AUTHOR]

The presence of the effect of thermally activated delayed fluorescence (TADF) in organic light-emitting materials (emitters), manifested in the "collecting" of triplet excitons in organic semiconductor complexes that do not contain noble metals, creates excellent prerequisites for the application of TADF materials in the technology of manufacturing organic light-emitting diodes (OLED). The significant progress in solving theoretical and technical problems, achieved in the process of development of highly efficient TADF materials, paves the way for the formation of the future of organic electronics. This review presents the analyses of the nature of the long-term fluorescence generation mechanism at the molecular level and the up-to-date strategies for designing TADF donor-acceptor materials, as well as exciplex intermolecular complexes. Special attention is focused on the analysis of TADF emitter ambipolar materials with a highly twisted, rigid molecular structure, which reveal a tendency towards the multi-channel emission mechanisms and their implementation in a variety of OLED structure architectures. [ABSTRACT FROM AUTHOR]

We present an innovative methodology for the synthesis of MXene membranes through a dual-stage process involving etching and subsequent thermal self-crosslinking. A molar ratio of 1 (Al3+):9 (F−) using HCl/LiF was employed to convert raw Ti3AlC2 (MAX phase) into MXene within 48 h at 40 °C. This procedure predominantly yielded monolayers distinguished by diameters exceeding 500 nm, elevated crystallinity and a high overall yield. Advanced characterization techniques, including FESEM, TEM, HRTEM, AFM, XPS, and FTIR, were utilized. Instrumental analysis confirmed the formation of MXene exhibiting a single-flake morphology with diameters exceeding 500 nm. These monolayers were intact and continuous, with smooth peripheries and a uniform thickness of 2.1 nm. The surfaces were predominantly composed of carbon (C), oxygen (O), and titanium (Ti) atoms, interconnected by chemical bonds such as C–Ti–O, C–Ti–OH, C–C, C–O, and Ti–O. In the subsequent phase, vacuum filtration facilitated the assembly of a self-supporting MXene membrane. Thermal treatment at 170 °C for 30 h resulted in the reinforcement of C–Ti–O bonds within the nanosheets, increasing their prevalence to 43.14 % and 19.47 %, respectively. This thermal regulation reduced the interlayer d-spacing from 4.33 to 3.54 Å, which significantly improved the gas separation efficiency beyond the Knudsen diffusion limit, as demonstrated by the αH2/CF4 value exceeding 23.0.

Inspired by “crimped” collagen fiber, which induce a low-level load region within the hierarchical structures of ligaments and tendons, this study introduces a braiding technology aiming at characterizing nonlinear mechanical behavior. Samples of the developed artificial ligament with a multilayer braided structure were fabricated and tested. Alterations in the number of braiding layers, wales, and courses significantly affect the mechanical properties of the artificial ligaments. Specifically, the toe length exhibited an increase of up to 104.58 %, while the linear stiffness exhibited variations concomitant with changes in these parameters. Additionally, a mathematical model to describe the relationship between the toe length and linear stiffness was developed based on the braiding parameters and material properties of the fibers. Alternative fibers were employed and tested to demonstrate a consistency with the mathematical model. The correlation coefficients were calculated as 0.9644 for the toe length and 0.9203 for the linear stiffness. Lastly, this study mimics the mechanical behavior of the human medial collateral ligament (MCL) by integrating the artificial ligament into a bio-fidelity knee model with a joint stiffness of 1.77 Nm/deg, resulting in a high degree of similarity with human knee in valgus-varus, further affirming the utility and applicability of this study.

The process flow for production of tinplate is usually comprising electroplating, reflowing, passivation, and oiling to form a multilayer structure with excellent comprehensive performance. There are some differences between the edge and center of tinplate due to the edge effect during electroplating and passivation. The microstructure and composition of the multilayer at the edge and center of tinplate were compared using scanning electron microscope (SEM), ultraviolet-visible spectrophotometer, electrochemical workstation, X-ray photoelectron spectroscope (XPS), and glow discharge spectroscope (GDS). The results showed that the various layers at the edge of tinplate was nonuniform in morphology and composition. As compared with the center of tinplate, the content of each component in the metallic tin layer, tin alloy layer, and passivate layer were higher at the edge, indicating that the tin coating at the edge of tinplate was oxidized more seriously. [ABSTRACT FROM AUTHOR]

Phase-transition materials, in particular chalcogenide glassy semiconductors and Ge–Sb–Te system materials, are of interest for application in optical information-processing technologies. The uniqueness of these materials lies in the fact that they have a low-energy, and fast and reversible phase transition, which leads to a significant change in the refractive index in the infrared region of the optical spectrum. The model calculations carried out in the work make it possible to investigate the transformation of the optical properties in multilayer structures consisting of SiO2, Si, Si3N4 layers and the active layer of a phase transition material when its phase state changes. The aim of these studies is to fulfill the condition of the lowest optical losses during the transmission and reflection of radiation of 1550 nm in such structures in the case of amorphous and crystalline states of the active layer, respectively. As a result, a nine-layer structure "SiO2//111 nm Si/277 nm SiO2/ 111 nm Si/251 nm SiO2/10 nm Ge2Sb2Se4Te/241 nm SiO2/110 nm Si/276 nm SiO2/112 nm Si//SiO2", which satisfies the specified conditions to the greatest degree, is designed. [ABSTRACT FROM AUTHOR]

The direct decomposition of toluene-containing humidified air at large flow rates was studied in two types of reactors with dielectric barrier discharge (DBD) features in ambient conditions. A scalable large-flow DBD reactor (single-layer reactor) was designed to verify the feasibility of large-flow plasma generation and evaluate its decomposition characteristics with toluene-containing humidified air, which have not been investigated. In addition, another large-flow DBD reactor with a multilayer structure (two-layer reactor) was developed as an upscale version of the single-layer reactor, and the scalability and superiority of the features of the multilayer structure were validated by comparing the decomposition characteristics of the two reactors. Consequently, the large-flow DBD reactor showed similar decomposition characteristics to those of the small-flow DBD reactor regarding applied voltage, flow velocity, flow rate, and discharge length, thus justifying the feasibility of large-flow plasma generation. Additionally, the two-layer reactor is more effective than the single-layer reactor, suggesting multilayer configuration is a viable scheme for further upscaled DBD systems. A high decomposition rate of 59.5% was achieved at the considerably large flow rate of 110 L/min. The results provide fundamental data and present guidelines for the implementation of the DBD plasma-based system as a solution for volatile organic compound abatement.

This paper proposes a nondestructive testing (NDT) method for the inspection of corrosion in rivets used in an aircraft. The NDT system uses an ultrasonic sensor coupling with a membrane that allows the ultrasonic wave propagates through to the inspecting rivet. The measured signal is then analyzed by a spiking neural network (SNN), a neural network that mimics the biological neurons for efficient detection of the corrosion in rivet. Compared to the conventional deep neural network, SNN is low energy consumption and can be implemented on a compact SNN accelerator chip, making them better run on a compact NDT system and general edge computing applications. We have tested the proposed SNN model on different sizes of corrosion in rivets (i.e., 30–70% of cross-section area) and at different depths from the surface (i.e., 1.0–2.0 mm). The proposed SNN model achieves about 95.4% accuracy with a small number of rivet samples (i.e., four rivet with corrosion) for training. [ABSTRACT FROM AUTHOR]

During this study, the resistivity of electrically conductive structures 3D-printed via fused filament fabrication (FFF) was investigated. Electrical resistivity characterisation was performed on various structural levels of the whole 3D-printed body, starting from the single traxel (3D-printed single track element), continuing with monolayer and multilayer formation, finalising with hybrid structures of a basic nonconductive polymer and an electrically conductive one. Two commercial conductive materials were studied: Proto-Pasta and Koltron G1. It was determined that the geometry and resistivity of a single traxel influenced the resistivity of all subsequent structural elements of the printed body and affected its electrical anisotropy. In addition, the results showed that thermal postprocessing (annealing) affected the resistivity of a standalone extruded fibre (extruded filament through a printer nozzle in freefall) and traxel. The effect of Joule heating and piezoresistive properties of hybrid structures with imprinted conductive elements made from Koltron G1 were investigated. Results revealed good thermal stability within 70 °C and considerable piezoresistive response with a gauge factor of 15–25 at both low 0.1% and medium 1.5% elongations, indicating the potential of such structures for use as a heat element and strain gauge sensor in applications involving stiff materials and low elongations. [ABSTRACT FROM AUTHOR]