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The development of heat metering has promoted the development of statistic models for the prediction of heat demand, due to the large amount of available data, or big data. Weather data have been commonly used as input in such statistic models. In order to understand the impacts of direct solar radiance and wind speed on the model performance comprehensively, a model based on Elman neural networks (ENN) was adopted, of which the results can help heat producers to optimize their production and thus mitigate costs. Compared with the measured heat demand, the introduction of wind speed and direct solar radiation has opposite impacts on the performance of ENN and the inclusion of wind speed can improve the prediction accuracy of ENN. However, ENN cannot benefit from the introduction of both wind speed and direct solar radiation simultaneously. [ABSTRACT FROM AUTHOR]

L10 ordered FePt and FePtCu nanoparticles (NPs) with a good dispersion were successfully fabricated by a simple, green, one-step solid-phase reduction method. Fe (acac)3, Pt (acac)2, and CuO as the precursors were dispersed in NaCl and annealed at different temperatures with an H2-containing atmosphere. As the annealing temperature increased, the chemical order parameter (S), average particle size (D), coercivity (Hc), and saturation magnetization (Ms) of FePt and FePtCu NPs increased and the size distribution range of the particles became wider. The ordered degree, D, Hc, and Ms of FePt NPs were greatly improved by adding 5% Cu. The highest S, D, Hc, and Ms were obtained when FePtCu NPs annealed at 750 °C, which were 0.91, 4.87 nm, 12,200 Oe, and 23.38 emu/g, respectively. The structure and magnetic properties of FePt and FePtCu NPs at different annealing temperatures were investigated and the formation mechanism of FePt and FePtCu NPs were discussed in detail. [ABSTRACT FROM AUTHOR]

A majority of the existing magnetodielectric (MD) effects based on spin‐lattice coupling or magnetic transitions are either too weak or far below room temperature, which challenges the potential applications of MD materials. Here, a giant room‐temperature MD coefficient of −62% at 1 Tesla (T) in disordered rutile NiNb2O6 (r‐NiNb2O6) ceramic in terms of the spin‐dependent polaron hopping is demonstrated. The r‐NiNb2O6 exhibits a near‐room‐temperature dielectric relaxation, which is ascribed to the polaron‐hopping‐induced grain polarization. This dielectric relaxation process, strikingly, can be controlled by the external magnetic field (H = 1 T) at 220 K< T< 310 K, achieving a giant MD coefficient of −62% (at 10k Hz) at 298 K. Further systematic investigations on the magnetic, electrical, and magnetoelectric coupling properties attribute the MD effect in r‐NiNb2O6 to a pure response of the spin‐dependent polaron hopping to applied magnetic field. This clearly reveals that the MD effect is subject to a competition among the polaron hopping activation, spin‐lattice coupling, and spin thermal fluctuation. [ABSTRACT FROM AUTHOR]

• Ca 1-1.5 x Sm x □ 0.5 x TiO 3 ceramics designed in terms of A-site donor Sm3+ and A-site vacancy (V A) were prepared by a solid state reaction method. • A-site donor Sm3+ and A-site vacancy (V A) strategy results in the greatly enhanced dielectric breakdown strength. • Ca 1-1.5 x Sm x □ 0.5 x TiO 3 ceramics present the linear dielectric feature with significantly decreased dielectric loss. • High energy storage density (U = 2.0 J/cm3) and energy efficiency (η = 93.7 %) are achieved. Ceramic-based capacitors for energy storage devices require simultaneously high energy density and efficiency. Achieving high electric breakdown field based on linear dielectrics is crucial. Here, A-site Sm3+ doped perovskite Ca 1-1.5 x Sm x □ 0.5 x TiO 3 ceramics with introduced A-site vacancies (V A) were prepared. All Ca 1-1.5 x Sm x □ 0.5 x TiO 3 ceramics crystallize in an orthorhombic structure, with lattice constants a , b , and c linearly decreased. As a result of Sm3+ dopants and V A , the grain size decreased while the ceramics' density was improved. The permittivity decreases from 176 (x = 0) to 135 (x = 0.1), but tan δ is effectively constrained (∼10−4). What's more, the dielectric breakdown strength is significantly improved from 429 kV/cm (x = 0) to 547 kV/cm (x = 0.1) with dielectric linearity is maintained. The optimum energy storage density of 2 J/cm3 (x = 0.02) with ultrahigh energy efficiency of over 93.7 % is achieved, which are superior to many existing linear dielectrics and relaxor ferroelectrics. This work confirms the energy-storage enhancement through chemical modifications and microstructural engineering. [ABSTRACT FROM AUTHOR]

The origins of the relaxor behavior and low-temperature dielectric relaxation processes in AgNb 7 O 18 ceramic were studied and a new relaxation mechanism was proposed through combined bond valence energy landscape (BVEL) calculation and equivalent circuit modeling (ECM). The BVEL calculation suggests that the Ag1 displacement subjects to a double-well potential that originates from the anisotropic coordination symmetry and low coordination number at Ag1 site. The relaxor ferroelectric behavior, observed at 200 K ≤ T ≤ 270 K, is sensitive to thermal history and is ascribed to the Ag1 hopping in double-well potential. The temperature dependence of the matrix capacitance (obtained by ECM) is very similar with that of b axis (obtained by in situ XRD) at 123 K < T < 174 K. Therefore, a phase transition being responsible for the low-temperature dielectric relaxation is assumed. The combined BVEL and ECM techniques performed in this work are therefore quite helpful to understand the complicated relaxor phenomena and explore new relaxors. [ABSTRACT FROM AUTHOR]

In situ integration of highly conductive metals into transitional metal oxide electrodes with enabling fast electron transfer kinetics is a plausible technique for improving electrochemical performances of electrode materials. Herein, for the first time, we demonstrate a rational configuration of conductive Ag flakes (FAg) that directly grown on CuO nanorods by in situ chemical approach. The obtained FAg–CuO hybrid electrode demonstrates a superior specific capacitance of 812 F/g at a current density of 2 A/g which is retained of about 110.37% after 5000 cycles. The solid-state asymmetric supercapacitor (ASC) based on FAg–CuO and active carbon is further fabricated. The ASC device similarly demonstrates remarkable performances with a high energy density of 40.02 Wh/kg at a power density of 1095.8 W/kg and also excellent cycling ability with stable capacitances output beyond 5000 cycles. The obtained superior performances are attributed to the rational Ag configurations which could effectively reduce the interfacial barriers and meanwhile enhance the electron transport and ion diffusion, with achieving the high-efficiency utilization for the active materials during Faradaic redox reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trinary-yarn-interlocked tribo/piezoelectric nanogenerator (HNG) is developed. • The HNG is constructed via knitting PTFE around BaTiO 3 /PDMS and AgNW/PDMS yarns. • The HNG exhibits a remarkable output voltage and power density. • This HNG marks breakthrough in harvesting biomechanical and deformation energy. Hybrid tribo/piezoelectric nanogenerator (HNG) is increasingly attracting the extensive attention because of the functional applications e.g. self-powered sensors and bio-motion energy harvesting etc. Although planar HNGs, the most studied currently, boast unrivaled output performances and structural simplicity, their coherent shortcoming e.g. flat/planar configurations still fall short for wearable electronics. To this end, a 3D trinary-yarn-interlocked HNG textile through knitting PTFE yarn around parallel-constructed two functional elastomer yarns i.e. piezoelectric BaTiO 3 /PDMS and triboelectric AgNW/PDMS has been developed. The resulting HNG textile demonstrates an exceptional biomechanical energy harvesting capability with generating a maximum peak power density of 91.6 mW m−2, which several-fold surpasses to the current 2D TENG textiles. The HNG textile can also response sensitively the various external mechanical stimulations by converting different forms of the bio-motion energy (e.g. biomechanical and deformation energy) into electrical signals. What's more, the collected power from the biomechanical/motion energy can sustainably charge commercial capacitors and power LED lights, with achieving a maximum output voltage of approximately 400 V. Most importantly, such a versatile all-in-one HNG possesses the highly structural durability, stability, and reliability during working, which promisingly offers continued bio-motion energy harvesting and enables exerting self-powered wearable sensing devices. This research presents an innovative approach to develop multifunctional, self-powered wearable textiles with high electrical performance, sturdy mechanical characteristics that demonstrate the potentially industrial applications in wearable tech aspects. [ABSTRACT FROM AUTHOR]

• L 1 0 ordered FePt and FePtC films were fabricated by electric treatment. • L 1 0 ordering phase transition doesn't need any heat treatment. • L 1 0 ordering phase transition can manipulate in a very short time. • The maximum values of H c and S of FePtC films are larger than those of FePt films. • FePtC films treated at higher voltage can get higher H c and S and smaller grain size. [Display omitted] We successfully fabricated L 1 0 ordered FePt and FePt-C(30 vol %) films without heat treatment by using electric treatment. The magnetic properties and structure of L 1 0 FePt and FePtC films with different applied voltage and treatment time(t) have been investigated. With the increase of t , the out-of-plane coercivity (H c) and chemical order parameter(S) of FePt films increase first and then decrease. The maximum values of H c and S of FePtC films are larger than those of FePt films treated at 30 V. FePtC films treated at higher applied voltage show excellent (001) texture, higher H c , S , smaller grain size and better perpendicular magnetic anisotropy. Electric treatment will not like thermal treatment which causes excessive grain growth. This study provides a new method for the ordering of other alloy thin films except for heat treatment. [ABSTRACT FROM AUTHOR]

The optical properties of silicon-on-insulator (SOI) samples, modified in Si thin film by multiple-time Si+ self-ion-implantation followed by annealing, have been well investigated. The SOI materials implanted by single energy can obtain many kinds of luminous centers, while the larger density appears in the samples implanted by multiple energy. After annealing at 700 °C, the sample implanted three times forms a luminescence peak with high luminescence intensity and narrow peak width near 0.8 eV. It is speculated that this peak is D1 peak and multiple implantation combined with high temperature annealing can promote the formation of D1 line luminous center in SOI. • The optical properties of silicon-on-insulator samples. • The large density appears in the multiple energy injection samples. • The D1 line appears near 0.8 ev. • Multiple injection combined with high temperature annealing can promote the formation of D1 line. [ABSTRACT FROM AUTHOR]

Achieving single-phase full-spectrum white light (SFWL) phosphors is a central goal in the optical field because they simplify white-LEDs assembly and avoid long-term color instability. Despite many approaches are developed, current SFWL phosphors still suffer from chromaticity drift due to inconsistent thermal quenching of multiple emitting centers. Herein, an absolutely structural disorder strategy is established to develop a single-emitting center-based SFWL phosphor. Precisely controlling the flux added induces a structural translation from the absolutely ordered Y 0.75 Ta 0.25 O 1.75 :Bi 3+ to the absolutely disordered Y 0.785 Ta 0.215 O 1.715 :Bi 3+ , as directly identified by STEM-HAADF analyses. Structural disorder enables Y 0.785 Ta 0.215 O 1.715 :Bi 3+ to produce SFWL with the FWHM of 6194 cm -1 (175 nm) by employing a single activator site, a 1352 cm -1 increase compared to the cyan-emitting Y 0.75 Ta 0.25 O 1.75 :Bi 3+ despite Bi 3+ occupies two lattice positions. This single-emitting center-based SFWL, coupled with minimal thermal expansion of the unit cell and inapparent spectral overlap of excitation and emission bands, ensure zero-chromaticity shift with elevated temperature. A prototype white-LEDs using Y 0.785 Ta 0.215 O 1.715 :Bi 3+ as a single luminescent layer generates warm white light without perceptible CIE coordinates shift under various currents or after extremely long-term continuous operation. This work highlights the potential of structural disorder in designing SFWL phosphors with exceptional color stability., (© 2024 Wiley‐VCH GmbH.)

High-entropy alloy nanoparticles (HEANs) possessing regulated defect structure and electron interaction exhibit a guideline for constructing multifunctional catalysts. However, the microstructure-activity relationship between active sites of HEANs for multifunctional electrocatalysts is rarely reported. In this work, HEANs distributed on multi-walled carbon nanotubes (HEAN/CNT) are prepared by Joule heating as an example to explain the mechanism of trifunctional electrocatalysis for oxygen reduction, oxygen evolution, and hydrogen evolution reaction. HEAN/CNT excels with unmatched stability, maintaining a 0.8V voltage window for 220 h in zinc-air batteries. Even after 20 h of water electrolysis, its performance remains undiminished, highlighting exceptional endurance and reliability. Moreover, the intrinsic characteristics of the defect structure and electron interaction for HEAN/CNT are investigated in detail. The electrocatalytic mechanism of trifunctional electrocatalysis of HEAN/CNT under different conditions is identified by in situ monitoring and theoretical calculation. Meanwhile, the electron interaction and adaptive regulation of active sites in the trifunctional electrocatalysis of HEANs were further verified by density functional theory. These findings could provide unique ideas for designing inexpensive multifunctional high-entropy electrocatalysts., Competing Interests: Competing interests statement:The authors declare no competing interest.

Wearable electronics with flexible, integrated, and self-powered multi-functions are becoming increasingly attractive, but their basic energy storage units are challenged in simultaneously high energy density, self-healing, and real-time sensing capability. To achieve this, a fully flexible and omni-healable all-hydrogel, that is dynamically crosslinked PVA@PANI hydrogel, is rationally designed and constructed via aniline/DMSO-emulsion-templated in situ freezing-polymerization strategy. The PVA@PANI sheet, not only possesses a honeycombed porous conductive mesh configuration with superior flexibility that provides numerous channels for unimpeded ions/electron transport and maximizes the utilization efficiency of pseudocapacitive PANI, but also can conform to complicated body surface, enabling effective detection and discrimination of body movements. As a consequence, the fabricated flexible PVA@PANI sheet electrode demonstrates an unprecedented specific capacitance (936.8 F g -1 ) and the assembled symmetric flexible all-solid-state supercapacitor delivers an extraordinary energy density of 40.98 Wh kg -1 , outperforming the previously highest-reported values of stretchable PVA@PANI hydrogel-based supercapacitors. What is more, such a flexible supercapacitor electrode enables precisely monitoring the full-range human activities in real-time, and fulfilling a quick response and excellent self-recovery. These outstanding flexible sensing and energy storage performances render this emerging PVA@PANI hydrogel highly promising for the next-generation wearable self-powered sensing electronics., (© 2023 Wiley-VCH GmbH.)

Thin, flexible, and electrically conductive films are in demand for electromagnetic interference (EMI) shielding. Two-dimensional NbSe 2 monolayers have an electrical conductivity comparable to those of metals (10 6 -10 7 S m -1 ) but are challenging for high-quality and scalable production. Here, we show that electrochemical exfoliation of flake NbSe 2 powder produces monolayers on a large scale (tens of grams), at a high yield (>75%, monolayer), and with a large average lateral size (>20 μm). The as-exfoliated NbSe 2 monolayer flakes are easily dispersed in diverse organic solvents and solution-processed into various macroscopic structures (e.g., free-standing films, coatings, patterns, etc.). Thermal annealing of the free-standing NbSe 2 films reduces the interlayer distance of restacked NbSe 2 from 1.18 to 0.65 nm and consequently enhances the electrical conductivity to 1.16 × 10 6 S m -1 , which is superior to those of MXenes and reduced graphene oxide. The optimized NbSe 2 film shows an EMI shielding effectiveness (SE) of 65 dB at a thickness of 5 μm (>110 dB for a 48-μm-thick film), among the highest in materials of similar thicknesses. Moreover, a laminate of two layers of the NbSe 2 film (2 μm thick) with an insulating interlayer shows a high SE of 85 dB, surpassing that of the 20-μm-thick NbSe 2 film (83 dB). A two-layer theoretical model is proposed, and it agrees with the experimental EMI SE of the laminated NbSe 2 films. The ability to produce NbSe 2 monolayers on a tens of grams scale will enable their diverse applications beyond EMI shielding.

Constructing three-dimensional (3D) hierarchical bimetallic pseudocapacitive materials with abundant opening channel and heterojunction structures is rather promising but still challenging for high-performance supercapacitors. Herein, a self-sacrifice-template epitaxial growth strategy was proposed for the first time to construct 3D hierarchical bimetallic pseudocapacitive material. By using this strategy, NiCo 2 O 4 nanowires (NiCo 2 O 4 NW) arrayed randomly to form a porous shell via in-situ epitaxial growth fully enclosing a MnO 2 tube core, forming multiple transport channels and nano-heterojunctions between MnO 2 and NiCo 2 O 4 NW, which facilitates electron transfer, i.e. exhibiting high electronic conductivity than any single component. As a result of the self-sacrifice-template epitaxial growth method, special hollow tectorum-like 3D hierarchical structure with considerable inter-nanowire space and hollow interior space enables easy access of electrolyte to NiCo 2 O 4 NW surface and MnO 2 core, thereby resulting in highly exposed redox active sites of MnO 2 core and NiCo 2 O 4 NW shell for energy storage. Comprehensive evaluations confirmed MnO 2 @NiCo 2 O 4 NW was a supercapacitor electrode candidate, delivering a superior energy density of 106.37 Wh kg -1 . Such performance can be ascribed to the synergistic coupling effect of 3D hierarchical tube and nano-heterojunction structures. The proposed self-sacrifice-template epitaxial growth strategy provides important guidance for designing high-performance energy storage materials., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The detrimental growth of lithium dendrites and unstable solid electrolyte interphase (SEI) inhibit the practical application of lithium-metal batteries. Herein, atomically dispersed cobalt coordinate conjugated bipyridine-rich covalent organic framework (sp 2 c-COF) is explored as an artificial SEI on the surface of the Li-metal anode to resolve these issues. The single Co atoms confined in the structure of COF enhance the number of active sites and promote electron transfer to the COF. The synergistic effects of the Co─N coordination and strong electron-withdrawing cyano-group can adsorb the electron from the donor (Co) at a maximum and create an electron-rich environment, hence further regulating the Li + local coordination environment and achieving uniform Li-nucleation behavior. Furthermore, in situ technology and density functional theory calculations reveal the mechanism of the sp 2 c-COF-Co inducing Li uniform deposition and promoting Li + rapid migration. Based on these advantages, the sp 2 c-COF-Co modified Li anode exhibits a low Li-nucleation barrier of 8 mV, and excellent cycling stability of 6000 h., (© 2023 Wiley-VCH GmbH.)

This paper studies the distributed interval state estimation problem for cyber-physical systems with bounded disturbance and random stealthy attacks. Since conventional interval observers cannot complete the task of real-time monitoring system under random attacks, an attack-resistant distributed interval observer is designed by using attack frequency and interval attack estimation. Using the designed observer, upper- and lower-bounding estimation error systems are modeled by positive interconnected systems with hybrid deterministic and random bounded inputs. To explicitly attenuate the effect of disturbance and attacks, the resulting deterministic positive error system between upper- and lower-bounding estimates is formulated. By linear programming, the results of interval observer design and l ∞ -gain optimization are proposed. The remote monitoring of vehicle lateral dynamic is given for numerical verification of the results., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 ISA. Published by Elsevier Ltd. All rights reserved.)

Carrier mobility and density are intrinsically important in nanophoto/electronic devices. High-dielectric-constant coupled polarization-field gate ferroelectrics are frequently studied and partially capable in achieving large-scale tuning of photoresponse, but their light absorption and carrier density seem generally ineffective. This raises questions about whether a similarly high-dielectric-constant paraelectric gate dielectric could enable tuning and how the principles involved could be established. In this study, by deliberately introducing lattice defects in high-dielectric-constant paraelectric, cubic BaTiO 3 (c-BTO) was explored to fabricate MoS 2 photodetectors with ultrahigh detection ability and outstanding field-effect traits. An organic-metal-based spin-coating cum annealing method was used for the c-BTO synthesis, with an optimized thickness (300 nm), by introducing lattice defects properly but maintaining a large dielectric constant (55 at 1k Hz) and low dielectric loss (0.06 at 1k Hz), which renders the enhanced visible-light region absorption. As a result of the synergistically enhanced mobility and photoabsorption, the MoS 2 /BTO FET exhibits promising merits, for example, on/off ratio, subthreshold swing, and mobilities for high-performance photodetectors with excellent responsivity (600 AW -1 ) and detectivity (1.25 × 10 12 Jones). Thus, this work facilitates the establishment of a lattice defect induced sub-bandgap absorption landmap for synergistically enhanced photoresponse for high-performance photodetector exploration.

For most of the non-Gaussian statistical models, the data being modeled represent strongly structured properties, such as scalar data with bounded support (e.g., beta distribution), vector data with unit length (e.g., Dirichlet distribution), and vector data with positive elements (e.g., generalized inverted Dirichlet distribution). In practical implementations of non-Gaussian statistical models, it is infeasible to find an analytically tractable solution to estimating the posterior distributions of the parameters. Variational inference (VI) is a widely used framework in Bayesian estimation. Recently, an improved framework, namely, the extended VI (EVI), has been introduced and applied successfully to a number of non-Gaussian statistical models. EVI derives analytically tractable solutions by introducing lower bound approximations to the variational objective function. In this paper, we compare two approximation strategies, namely, the multiple lower bounds (MLBs) approximation and the single lower bound (SLB) approximation, which can be applied to carry out the EVI. For implementation, two different conditions, the weak and the strong conditions, are discussed. Convergence of the EVI depends on the selection of the lower bound, regardless of the choice of weak or strong condition. We also discuss the convergence properties to clarify the differences between MLB and SLB. Extensive comparisons are made based on some EVI-based non-Gaussian statistical models. Theoretical analysis is conducted to demonstrate the differences between the weak and strong conditions. Experimental results based on real data show advantages of the SLB approximation over the MLB approximation.

Lattice disorder has emerged as a novel strategy to realize visible-light photocatalytic activity, but many existing studies often involved reduction states simultaneously. Photocatalysts based on only the lattice disorder but without the reduction states are still quite lacking and challenging. To this end, we explored a new type of lattice disorder in terms of the surface atom nonstoichiometry strategy in BaTiO 3 . Well-dispersed tetragonal BaTiO 3 nanocrystals with a uniform size (∼20 nm) and cuboid morphology were hydrothermally synthesized through controlling over t -butylamine and oleic acid. HRTEM coupled with structural evolution analysis reveals the existence of a Ti-rich layer on BaTiO 3 nanocrystals with surface atom disorder, which gives an overall Ti/Ba ratio of 1.50:1. This is mainly dominated by the oriented adsorption between oleic acid and surface Ba 2+ of the nucleus during solution reaction. Such a surface disorder and Ti-rich nonstoichiometry effect could facilitate the enhanced visible-light absorption with a wavelength span of 400-700 nm that enables the superior visible-light photocatalytic property, which is not subject to the reduction states. This work demonstrates a first white material presenting a new type of lattice disorder that would be helpful for a wide range of photocatalyst explorations., Competing Interests: The authors declare no competing financial interest.