Abstract This work introduces a silent speech interface (SSI), proposing a few-layer graphene (FLG) strain sensing mechanism based on thorough cracks and AI-based self-adaptation capabilities that ...overcome the limitations of state-of-the-art technologies by simultaneously achieving high accuracy, high computational efficiency, and fast decoding speed while maintaining excellent user comfort. We demonstrate its application in a biocompatible textile-integrated ultrasensitive strain sensor embedded into a smart choker, which conforms to the user’s throat. Thanks to the structure of ordered through cracks in the graphene-coated textile, the proposed strain gauge achieves a gauge factor of 317 with <5% strain, corresponding to a 420% improvement over existing textile strain sensors fabricated by printing and coating technologies reported to date. Its high sensitivity allows it to capture subtle throat movements, simplifying signal processing and enabling the use of a computationally efficient neural network. The resulting neural network, based on a one-dimensional convolutional model, reduces computational load by 90% while maintaining a remarkable 95.25% accuracy in speech decoding. The synergy in sensor design and neural network optimization offers a promising solution for practical, wearable SSI systems, paving the way for seamless, natural silent communication in diverse settings.
This paper is concerned with application problem of optimal control to a class of dynamic advertising models with multiple delays. Here, a dynamic model with state and control delays is introduced to ...describe the impacts of advertising delayed and memory effects on the evolution of brand goodwill. In the decentralized and centralized systems, the optimal advertising strategies of supply chain members are presented by utilizing the nonzero-sum differential game governed by differential equation with multiple delays in state and control variables. Special effort is made to analyse the geometrical shapes of advertising strategy and provide the optimal decision structure of supply chain system. Furthermore, nonzero-sum stochastic differential game is applied to explore the dynamic advertising decision problems of supply chain system with the multiple delays and stochastic cases. Finally, numerical examples are exploited to illustrate the effectiveness of the proposed results.
Dielectric metasurfaces have shown prominent applications in nonlinear optics due to strong field enhancement and low dissipation losses at the nanoscale. Chalcogenide glasses are one of the ...promising materials for the observation of nonlinear effects thanks to their high intrinsic nonlinearities. Here, we demonstrate, experimentally and theoretically, that significant second harmonic generation (SHG) can be obtained within amorphous Selenium (Se)-based chalcogenide metasurfaces by exploiting the coupling between lattice and particle resonances. We further show that the high-quality factor resonance at the origin of the SHG can be tuned over a wide wavelength range using a simple and versatile fabrication approach. The measured second harmonic intensity is orders of magnitude higher than that from a dewetted Se film consisting of random Se nanoparticles. The achieved conversion efficiency in the resonance region is of the order of 10
which is comparable with direct bandgap materials and at least two orders of magnitude higher than that of conventional plasmonics- and Si-based structures. Fabricated via a simple and scalable technique, these all-dielectric architectures are ideal candidates for the design of flat nonlinear optical components on flexible substrates.
Developing cost-effective, active and robust electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in the same electrolyte still remains a crucial ...challenge for boosting the efficient conversion of sustainable energy resources. Here, based upon rapid solidification and the dealloying inheritance effect, a eutectic-derived self-templating strategy is reported to fabricate hierarchically porous Mo-doped Ni–Fe oxide nanowires for catalyzing overall water splitting. The advanced catalyst exhibits a remarkably low overpotential (only requires an overpotential of 231 mV for 10 mA cm −2 ) and low Tafel slope (39 mV dec −1 ) towards the OER in 1 M KOH. Comparing with the Ni–Fe oxide without Mo-doping, the Mo-doped Ni–Fe oxide nanowires show enhanced activities towards the HER with 84 mV less overpotential to drive a current density of 10 mA cm −2 . Strikingly, an alkaline electrolyzer assembled by using the Mo-doped Ni–Fe oxide nanowires as both the anode and the cathode consumes a cell voltage as low as 1.62 V (at 10 mA cm −2 ). The exceptional properties of the catalyst can be ascribed to its well-designed hierarchically porous nanowire network, and enhanced electric conductivity profiting from the remaining Ni metal in the oxide, as well as the synergistic effect of Mo and the Ni–Fe system. These favorable factors concurrently contribute to the boosted active surface area, facilitated electron/electrolyte transport, and accelerated reaction kinetics of water splitting.
For lithium ion batteries (LIBs), low electronic conductivity of CuO leads to rapid capacity decay and poor structural stability. Herein, we successfully fabricate three-dimensional CuO nanoflake ...arrays coated Cu foam by facile and efficient electrochemical oxidation. When being applied as anode material for LIBs, the CuO electrodes deliver stable reversible capacities of 523.9 mA h g−1 at 0.5 A g−1, 376.1 mA h g−1 at 1.0 A g−1 and 322.7 mA h g−1 at 2.0 A g−1 with high coulombic efficiency (>99%) after 100 cycles. A long cycle life of up to 400 cycles at 2.0 A g−1 is also achieved with the retention capacity of 193.5 mA h g−1. Moreover, the electrode exhibits excellent rate capability and can regain its original capacities as reversing to the low current densities. Noticeably, on-line differential electrochemical mass spectrometry and in situ Raman measurements confirm the formation of solid electrolyte interface film and the conversion mechanism for the CuO electrodes, respectively. The superior lithium storage performance can be attributed to the favorable nanoflake structures with high surface area and the perfect electrical contact between CuO and Cu substrate.
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•We fabricate CuO nanoflakes coated Cu foam by in situ electrochemical oxidation.•The CuO electrodes deliver stable reversible capacities at high current densities.•The CuO electrodes exhibit a long cycle life of up to 400 cycles at 2.0 A g−1.•In situ Raman measurement confirms the conversion mechanism for CuO electrodes.
The mass production of clean hydrogen fuels via (photo)electrochemical water splitting calls for highly efficient, cost-effective, and eco-friendly catalysts. Herein, a facile and scalable strategy, ...namely, dealloying, is advanced to fabricate mesoporous ternary layered double hydroxides (LDHs) containing Co, Ni, and Fe for highly efficient oxygen evolution and overall water splitting, based upon elaborate design of precursors and accurate control of the dealloying process. The Co1Ni2Fe1-LDH exhibits remarkable catalytic properties toward oxygen evolution reaction in 1 M KOH, for instance low overpotentials (only requires 240.4 mV on glass carbon electrode, and 228.5 mV on Ni foam to drive 10 mA cm–2), a small Tafel slope (38.6 mV dec–1), as well as excellent stability (lasts 45 h for 10 mA cm–2 without deactivation). Surprisingly, a symmetric alkaline electrolyzer constructed with Co1Ni2Fe1-LDH serving as the catalyst for both cathode and anode requires only 1.65 V to drive 10 mA cm–2. The distinguished features of the catalysts lie in the combined effects of the unique LDH structure with large interlayer spaces, the 3D porous structure, and the synergistic interplay of the metal species, concurrently contributing to the fully exposed active sites, accelerated electrolyte penetration and charge/ion transfer, as well as the well-promoted reaction kinetics. The consolidation of the electrocatalytic merits and the facile, economical fabrication route endows the ternary CoNiFe-LDHs as promising catalysts for the generation of renewable energy resources.
Highly sensitive and efficient biosensors play a crucial role in clinical, environmental, industrial, and agricultural applications, and tremendous efforts have been dedicated to advanced electrode ...materials with superior electrochemical activities and low cost. Here, we report a three-dimensional binder-free Cu foam-supported Cu2O nanothorn array electrode developed via facile electrochemistry. The nanothorns growing in situ along the specific direction of have single crystalline features and a mesoporous surface. When being used as a potential biosensor for nonenzyme glucose detection, the hybrid electrode exhibits multistage linear detection ranges with ultrahigh sensitivities (maximum of 97.9 mA mM–1 cm–2) and an ultralow detection limit of 5 nM. Furthermore, the electrode presents outstanding selectivity and stability toward glucose detection. The distinguished performances endow this novel electrode with powerful reliability for analyzing human serum samples. These unprecedented sensing characteristics could be ascribed to the synergistic action of superior electrochemical catalytic activity of nanothorn arrays with dramatically enhanced surface area and intimate contact between the active material (Cu2O) and current collector (Cu foam), concurrently supplying good conductivity for electron/ion transport during glucose biosensing. Significantly, our findings could guide the fabrication of new metal oxide nanostructures with well-organized morphologies and unique properties as well as low materials cost.
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Recently, hyaluronic acid (HA) hydrogels have been extensively researched for delivering cells and drugs to repair damaged tissues, particularly articular cartilage. However, the in ...vivo degradation of HA is fast, thus limiting the clinical translation of HA hydrogels. Furthermore, HA cannot bind proteins with high affinity because of the lack of negatively charged sulfate groups. In this study, we conjugated tunable amount of sulfate groups to HA. The sulfated HA exhibits significantly slower degradation by hyaluronidase compared to the wild type HA. We hypothesize that the sulfation reduces the available HA octasaccharide substrate needed for the effective catalytic action of hyaluronidase. Moreover, the sulfated HA hydrogels significantly improve the protein sequestration, thereby effectively extending the availability of the proteinaceous drugs in the hydrogels. In the following in vitro study, we demonstrate that the HA hydrogel sulfation exerts no negative effect on the viability of encapsulated human mesenchymal stem cells (hMSCs). Furthermore, the sulfated HA hydrogels promote the chondrogenesis and suppresses the hypertrophy of encapsulated hMSCs both in vitro and in vivo. Moreover, intra-articular injections of the sulfated HA hydrogels avert the cartilage abrasion and hypertrophy in the animal osteoarthritic joints. Collectively, our findings demonstrate that the sulfated HA is a promising biomaterial for the delivery of therapeutic agents to aid the regeneration of injured or diseased tissues and organs.
In this paper, we conjugated sulfate groups to hyaluronic acid (HA) and demonstrated the slow degradation and growth factor delivery of sulfated HA. Furthermore, the in vitro and in vivo culture of hMSCs laden HA hydrogels proved that the sulfation of HA hydrogels not only promotes the chondrogenesis of hMSCs but also suppresses hypertrophic differentiation of the chondrogenically induced hMSCs. The animal OA model study showed that the injected sulfated HA hydrogels significantly reduced the cartilage abrasion and hypertrophy in the animal OA joints. We believe that this study will provide important insights into the design and optimization of the HA-based hydrogels as the scaffold materials for cartilage regeneration and OA treatment in clinical setting.
Purpose
To analyze how family resilience mediates the relationship between childhood trauma and psychological resilience in undergraduate nursing students.
Design and Methods
A cross‐sectional survey ...design was used to investigate 698 nursing undergraduate students (mean age: 18.77 ± 0.86 years) using the Childhood Trauma Questionnaire, Family Resilience Assessment Scale, and Connor–Davidson Resilience Scale. The mediating effect of family resilience was estimated using structural equation modeling and the bootstrap method.
Findings
Both childhood trauma and family resilience were associated with psychological resilience. Family resilience showed a partial mediating effect between childhood trauma and psychological resilience, accounting for 21.5% of the total effect.
Practice Implication
Our findings may help inform family interventions to improve the psychological resilience of nursing students, especially for those with childhood trauma experience.
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