The demand for bio-inspired neuromorphic systems drives research on artificial neuronal devices with dual excitatory/inhibitory capabilities. Although perovskite memristors show promise, interfacial barriers and rapid ion migration hinder modulation. This study addresses these challenges through atomic-scale cathode engineering, developing perovskite-based memristor (Au/Ni1-rGO/MAPbI3/ITO) with nickel single-atom modified reduced graphene oxide (Ni1-rGO) cathode. The Ni-O configuration of Ni1-rGO with a single Ni atom anchored on rGO, modulates the electronic properties of rGO, reducing Schottky barrier via energy band alignment for bipolar current symmetry and spatially confining iodide ion migration through a high diffusion energy barrier (2.912 eV), conferring 780 ms relaxation. The device achieves 1,000 distinct conductance states and emulates interlayer connections and bidirectional signal transmission in feedback neuronal networks. We demonstrate neuromorphic functionalities: unsupervised competitive learning exceeds 50% clustering accuracy, while cooperative learning solves NP-hard problem 6× faster than simulated annealing, establishing an atomic-engineered approach for high-efficiency neuromorphic hardware.

To overcome the drawback of the brittle borides formed in the stainless steel joint brazed using Ni-based filler metals and further improve the mechanical properties of the joint， a small amount of Cu powders are added into the BNi-2 filler metal to suppress the formation of brittle borides in the joints. The 304 stainless steels are brazed using the BNi-2 and BNi-2 with Cu as filler metals， respectively. The influences of holding time， brazing temperature， and Cu content on the microstructure and mechanical properties of the brazed joints are investigated. The results indicate that for the BNi-2 filler metal， increasing the brazing temperature and time are favorable for reducing the boride content formed in the joint center. In addition， increasing the brazing temperature and time can accelerate the intergranular diffusion of borides， thereby leading to a degradation of joint shear strength. For the BNi-2 filler metal with Cu， when the Cu content is 1%（mass fraction，the same below）， the borides in the joint center are inhibited remarkably， forming a full Ni-based solid solution in the joint center. The joint shear strength obtained is （713.9±16.4） MPa， which is 19% higher than that of the joint without Cu additive. The joint failure occurs at the base metal/filler metal interface， recognized as a ductile fracture. However， when the Cu content increases to 5%， the borides reprecipitate in the joint center， resulting in the reduction of shear strength. In this case， the joint failure evolves to a composite mode with the co-existence of ductile and brittle fracture.

Diamond brazing is a critical joining technique for advanced thermal management and cutting applications, where joint reliability primarily depends on the resulting interlayer. In this study, first-principles calculations were conducted to investigate the effects of multi-element interaction on phase compatibility and interfacial adhesion in the AgCuSnTi/diamond brazing system. Adsorption and charge-transfer characteristics of Ag, Cu, Sn, and Ti atoms on diamond were first examined, revealing that Ti exhibited the strongest electronic interaction and acted as the primary wetting agent that enhanced interfacial bonding. To capture the compositional complexity of the interlayer, major phases were doped with additional filler elements. The calculated formation energies and mechanical parameters demonstrated strong composition dependence, with certain doped configurations compromising thermodynamic and mechanical stability. Moreover, layer-specific segregation at the diamond interface indicated that interface-closest segregation severely weakened bonding strength and facilitated premature fracture. Electronic structure and charge density analyses clarified the bonding disruption mechanisms. These results could advance the understanding of microstructure-property relationships in carbon-based materials brazed with AgCuSnTi fillers.

Proton exchange membrane (PEM) water electrolysis is an exceptionally appealing technology that facilitates the acquisition of environmentally friendly and sustainable hydrogen fuel. The multi-valent properties and unique structural flexibility make perovskite a promising contender for addressing the sluggish kinetics of the acidic oxygen evolution reaction (OER) in PEM with less use of precious metals. However, the intrinsic active configurations of these perovskite catalysts are always unpredictable, posing a challenge for us to gain a profound comprehension of their catalytic mechanisms and use them for targeted design of efficient catalysts. This review presents a comprehensive summary of the active structures of various perovskite-type electrocatalysts employed for acidic OER in the past five years, classifying them into crystal metal-oxygen octahedral structure (C-BO6), amorphous counterparts (A-BOx), and their derivative structures. Furthermore, it discusses the utilization of theoretical calculations and advanced characterization techniques to identify active sites in perovskite-type electrocatalysts, aiming to enhance our understanding of the acidic OER mechanism. Finally, it delivers the outstanding concerns surrounding perovskite-type electrocatalysts in acidic OER and outline some potential direction.

To address the issue of excessively high joining temperatures of silicon carbide(SiC)ceramics in the traditional nano-infiltrated transient eutectic(NITE)method,a method utilizing spark plasma sintering(SPS)diffusion bonding with a SiC-based interlayer containing YF3 powder was proposed to reduce the joining temperature.The effects of joining temperature,holding time,and YF3 content on the microstructure and mechanical properties of the joints were investigated.The results indicate that increasing the joining temperature and holding time significantly enhances the densification of the interlayer powder and improves the mechanical properties of the joints.The interlayer is primarily composed of 3C-SiC,along with phases such as Si-rich SiC1-x,C-rich SiC1+x,YxCy,and YxSiyCz.The phase composition of the joints is influenced by the joining process.With increasing YF3 content,YxSiyCz initially forms,followed by the precipitation of YxCy and a decrease in the amount but an increase in the size of YxSiyCz.Consequently,the densification and strength of the joints first increase and then decrease,while the hardness gradually increases.Under the optimal joining process(1 750 ℃/10 min/5％YF3),the hardness of the interlayer reaches 2 013.1 HV±74.1 HV,comparable to that of the base material.The room-temperature shear strength is 181.9 MPa±55.2 MPa,and fracture occurs within the base material.

Due to the inherent brittleness and joining challenges of Si3N4 ceramics, this study explored the application of TiZrHfTa refractory high-entropy alloy (RHEA) as interlayer to enhance diffusion bonding performance and mechanical reliability through spark plasma sintering (SPS). Si3N4/TiZrHfTa/Si3N4 joints with two different thicknesses of interlayers (100 mu m and 30 mu m) were investigated for microstructure evolution, mechanical properties and joining mechanism. The highest joint shear strength of 312.6 +/- 3.2 MPa was achieved when bonded at 1600 degrees C for 10 min with a 30 mu m interlayer. The results indicated an optimal interlayer thickness promotes the complete transformation of the silicide reaction layer into a high-entropy nitride layer. When the interlayer was reduced from 100 mu m to 30 mu m, the reaction layer, which was dominated by (TiZrHfTa)Si, became dominated by the high entropy nitride (TiZrHfTa)N, which is the main reason for the higher performance of the joints with 30 mu m interlayer.

The Mo-14Re/Inconel 625 alloy joint brazed using traditional BNi-2 or Cu interlayers generally exhibited unsatisfactory bonding strength and cracks due to a large mismatch of coefficient of thermal expansion (CTE) between the base materials. In this study, Mo-14Re and Inconel 625 were brazed using two routes: 1) One-step brazing with Au-Ni paste achieved a shear strength up to 547.9 MPa, due to the predominance of high-strength and ductile Au(s,s) in the brazed joint; 2) Two-step brazing with Ti-Zr-Cu-Ni filler and Nb interlayer, which regulated the formation of the brittle intermetallic compounds and residual stress, produced a crack-free brazed joint.

Copper-clad ceramic plate is an important heat dissipation component in an insulate-gate bipolar transistor(IGBT),which is composed of high thermal conductivity ceramic and pure copper connection.Active metal brazing is an important way to realize high-performance manufacturing of copper-clad plate.The low-expansion Y2O3 particles were used to enhance the Ag-Cu-Ti-based composite brazing alloy for connecting AlN and copper.The effect of brazing process(brazing temperature and holding time)and Y2O3 content in the brazing alloy on the microstructure and mechanical properties of the joint was systematically studied.The mechanism of joint formation was clarified,and the relationship between the microstructure and mechanical properties of the joint was established.The results show that increasing brazing temperature or extending holding time is beneficial to forming a uniform and dense brazing structure.Appropriate Y2O3 content(1%-3%)in the brazing alloy can refine the grain,alleviate the thermal mismatch of the joint,and improve the joint performance,but too much Y2O3(4%-5%)will lead to particle agglomeration and welding defects.The shear strength of AlN/Cu joint obtained by Ag-Cu-Ti+3%Y2O3 composite brazing alloy at 850℃/10 min is 275 MPa,which is the highest value reported in the literature.This study provides theoretical and technological guidance for high-performance manufacturing of an IGBT copper-clad ceramic plate.

The preparation of N-doped conductive SiC ceramics through conventional solid-state sintering typically requires extremely high temperatures and additional nitrogen solid solution treatments. To overcome this limitation, pre-synthesized N-doped SiC nanopowder containing 1 wt.

All-solid-state Li-ion batteries (ASSLIBs) hold promises in addressing the safety issues of liquid electrolyte batteries, garnering widespread interest. The development of ASSLIBs critically depends on the discovery of inorganic solid-state electrolytes (ISSEs) with high Li-ion conductivity and good electrochemical stability. Herein, we propose a machine learning (ML)-assisted hierarchical screening strategy to rapidly and accurately identify promising ISSE candidates from a pool of 20,717 Li-containing materials. A pre-screening was conducted based on a series of criteria, followed by the application of ML technique to develop predictive models aimed at identifying materials with high ionic conductivity. Data on Li-ion conductivity of various ISSEs was compiled from literatures to create a supportive database of 468 samples for the ML strategy. Different algorithms were tested for both classification and regression tasks to maximize the accuracy of the ML prediction. Moreover, the electrochemical window was evaluated for the identified candidates. Ab initio molecular dynamics simulation was conducted to determine the Li-ion transport properties of the screened materials. Ultimately, three candidates, namely Li3BiS3, Li5BiS4, and Li10ZnP4S16, were identified as promising due to their high Li-ion conductivity at room temperature. Their chemical reactivity with common cathodes were assessed to evaluate their compatibility. This work will be expected to advance the discovery of novel ISSEs for ASSLIBs.

All-solid-state Li-ion batteries (ASSLIBs) have attracted great attention due to their intrinsic safety and high potential energy density. To realize ASSLIBs, the development of solid-state electrolytes (SSEs) with favorable electrochemical stability and high Li-ion conductivity is of utmost significance. Compared to trial-and-error searches, theoretical computation-based methods are recognized as a powerful tool for accelerating the exploration of SSEs. However, the development of appropriate descriptors is often the first hurdle toward implementing accurate and meaningful screening process. Here we quantified the structural properties pertaining to low Li-ion migration barriers and performed a high-throughput screening of 3119 Li-containing halides obtained from the Materials Project (MP) database to search for promising SSEs. After excluding previously reported SSEs, three candidate materials, Li4ZrF8, Li3ErBr6, and Li2ZnI4 with crystal structure exhibiting 3D diffusion pathway were obtained. Subsequent theoretical calculations of these materials were performed to evaluate their thermodynamic stability, chemical/electrochemical stability, and ionic conductivity. The three halide materials appeared to be promising SSE candidates due to their robust thermodynamical stability against cathodes, and high ionic conductivity. This research provides a new insight and a systematic quantitative understanding of the relationship between the structural properties and Li-ion migration barriers, which can motivate future computational studies on new fast-ion conductors and accelerate the discovery of high ionic conductivity SSEs for the use in ASSLIBs.

To achieve low‐stress and small‐deformation welding of thin‐walled structures for the fourth‐generation nuclear power plants, GH3535 superalloy is welded to itself using electron beam welding (EBW). The microstructure and mechanical properties of the GH3535 superalloy joints are characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), hardness, and tensile tests. A macro‐defect‐free GH3535 superalloy joint could be obtained using 22 mA welding beam current under 65 kV welding voltage with 300 mm min−1 welding speed. Different sub‐grain solidification morphologies are observed at the weld zone because of the influence of composition undercooling on the solidification process of the weld pool. The M6C type carbides formed in the weld zone and heat‐affected zone (HAZ) take place eutectic transformation under the action of thermal cycles. The eutectic transformation of M6C has no significant effect on the strength of HAZ, whereas this phenomenon is beneficial to hinder the dislocation movement in the weld zone, thereby promoting the tensile strength of the joint. The Vickers hardness of weld zone and HAZ are 250.6 and 252 HV0.5, remarkably lower than that of the base metal (261.2 HV0.5), due to the grain coarsening in those zones. The tensile strength of the GH3535 superalloy joint reached 791 MPa, ≈93.5% that of the base metal, with the fracture occurred in the weld zone.

Machine vision systems that consist of cameras and image-processing components for visual inspection and identification tasks play a critical role in various intelligent applications, including pilotless vehicles and surveillance systems. However, current systems usually possess a limited dynamic range and fixed photoresponsivity, restricting their capability of gaining high-fidelity images when encoding a high-contrast scene. Here, it is shown that a photovoltaic memristor incorporating two antagonistic photovoltaic junctions can autonomously adjust its response to varying light stimuli, enabling the amplification of shadows and inhibition of highlight saturation. Due to the dynamic photodoping effect at the p-n junction with an asymmetrical profile, the photocurrent polarities of the antagonistic memristor can be changed as the light intensity increases. The light-intensity-dependent switchable photovoltaic behaviors match Weber's law where photosensitivity is inversely proportional to the light stimuli. An 11 × 11 memristor array is used to detect a high-contrast scene with light intensities ranging from 1 to 5 × 104 µW cm-2, achieving a similar active contrast adaptation performance compared with the human visual systems (less than 1.2 s at 94 dB). This work paves the way for innovative neuromorphic device designs and may lead to the development of state-of-the-art active visual adaptation photosensors.

High-performance perovskite materials with excellent physical, electronic, and optical properties play a significant role in artificial neuromorphic devices. However, the development of perovskites in microelectronics is inevitably hindered by their intrinsic non-ideal properties, such as high defect density, environmental sensitivity, and toxicity. By leveraging materials engineering, integrating various materials with perovskites to leverage their mutual strengths presents great potential to enhance ion migration, energy level alignment, photoresponsivity, and surface passivation, thereby advancing optoelectronic and neuromorphic device development. This review initially provides an overview of perovskite materials across different dimensions, highlighting their physical properties and detailing their applications and metrics in two- and three-terminal devices. Subsequently, we comprehensively summarize the application of perovskites in combination with other materials, including organics, nanomaterials, oxides, ferroelectrics, and crystalline porous materials (CPMs), to develop advanced devices such as memristors, transistors, photodetectors, sensors, light-emitting diodes (LEDs), and artificial neuromorphic systems. Lastly, we outline the challenges and future research directions in synthesizing perovskite composites for neuromorphic devices. Through the review and analysis, we aim to broaden the utilization of perovskites and their composites in neuromorphic research, offering new insights and approaches for grasping the intricate physical working mechanisms and functionalities of perovskites.

Joining diamond and metal is vital to expand their application scope in electronic and military industries. A metallic carbide layer will be inevitably introduced on diamond to ensure strength and wettability, its tight interfacial adhesion with diamond needs to be satisfied in priority. Here, the bonding characteristics of diamond(001)/carbide(001) interfaces were comparatively studied through first-principles calculations, wherein six experimentally possible carbides MxCy (TiC, Cr3C2, V8C7, Mo2C, ZrC, and WC) were employed. By evaluating the thermal stability, activity, and mechanical properties of bulk MxCy, as well as the corresponding interface energy and adhesion work, three outstanding interface structures (with Cr, W, and Ti) were yielded. Further analysis of electronic structures showed the interfacial bonding originated from M–C bonds and stronger CC covalent bonds. Besides, bonding strength was found to be significantly related to interfacial charge density and orbital hybridization. Overall, Cr might be the preferable carbide former with high interfacial stability and strength. This study provided atomic insights into the tailoring of diamond/carbide combination with superior interfacial compatibility to develop high-performance diamond devices.

All-solid-state lithium (Li) ion batteries (ASSLIBs) have attracted widespread attention due to their sufficient energy density and safety. Further advancement of ASSLIBs necessitates the discovery of solid-state electrolyte (SSE) materials. In this work, we conducted a computational investigation utilizing first-principles calculations to identify the functional parameters and interfacial properties of a novel iodide-based ion conductor (Li3ZrI6). The Li3ZrI6 exhibited excellent Li-ion conductivity and robust chemical/electrochemical stability, emerging as a promising SSE candidate. This research could facilitate the pursuit of high-performance SSEs for related applications.

Integrated zirconium (Zr) alloy fuel claddings require low-temperature and high-efficiency joining technologies for nuclear applications. However, conventional direct-joining technologies make it challenging to satisfy critical requirements at relatively low temperatures in a short time. As a promising alternative, the electric-current-assisted joining (ECAJ) method was studied to reduce the joining temperature and time required for the direct joining process. ECAJ was performed on a spark plasma sintering apparatus, with the specimens assembled with and without graphite dies in the two models. The microstructural evolution and mechanical properties of Zr/Zr joints were investigated at 600 - 900 degrees C for 1 s to 30 min under a pressure of 30 MPa using different configurations with or without a graphite die. While the joint quality varied with the joining conditions, no significant phase transformation, abnormal grain growth, or preferential orientation was observed at the interface. The maximum shear strength of 404 +/- 78 MPa and hardness of 370.9 +/- 49.8 HV were achieved at 600 degrees C for 10 min using a die-less configuration. The joining mechanism was discussed in terms of the potential thermal and electric effects inside the specimen, with the low-temperature joining mechanism attributed to the combined effect of transient overheating and electric-field-accelerated element self-diffusion at the interface, with the latter playing a leading role.

To reduce the sintering temperature of liquid-phase sintered conductive SiC ceramics, the SiC nanopowder with Sc2O3 additives was intentionally oxidized by heat treatment in air to enhance the SiO2 content coated on SiC surfaces moderately. Taking advantage of the lower eutectic temperature (1660 °C) between SiO2 and Sc2O3, conductive SiC ceramics were successfully sintered at 1700 °C. The effects of sintering temperature (1700–1900 °C), holding time (1–10 min), and additive content (1–7 wt.

The microwave window unit is the core component of the electron cyclotron heating and current drive (EC H CD) system used in fusion reactors. In this work, a diamond disk for the microwave window was designed according to the electromagnetic propagation theory. Then, the finite element method was employed to build a microwave window model based on our tailored dimension. The effect of brazing and subsequent service processes on the stress/strain distributions and electrical parameters were explored. Overall, the microwave window exhibited excellent performance, with the maximum principal stress of the brazed disk under service being 51 MPa, which was much lower than the allowable stress of diamond. It was also indicated that the electrical properties barely changed, which could satisfy functional requirements. This work provided theoretical guidance for the design and manufacture of diamond microwave windows used in fusion reactors.

Physical reservoir-based reservoir computing (RC) systems for intelligent perception have recently gained attention because they require fewer computing resources. However, the system remains limited in infrared (IR) machine vision, including materials and physical reservoir expression power. Inspired by biological visual perception systems, the study proposes a near-infrared (NIR) retinomorphic device that simultaneously perceives and encodes narrow IR spectral information (at ≈980 nm). The proposed device, featuring core-shell upconversion nanoparticle/poly (3-hexylthiophene) (P3HT) nanocomposite channels, enables the absorption and conversion of NIR into high-energy photons to excite more photo carriers in P3HT. The photon-electron-coupled dynamics under the synergy of photovoltaic and photogating effects influence the nonlinearity and high dimensionality of the RC system under narrow-band NIR irradiation. The device also exhibits multilevel data storage capability (≥8 levels), excellent stability (≥2000 s), and durability (≥100 cycles). The system accurately identifies NIR static and dynamic handwritten digit images, achieving recognition accuracies of 91.13% and 90.07%, respectively. Thus, the device tackles intricate computations like solving second-order nonlinear dynamic equations with minimal errors (normalized mean squared error of 1.06 × 10⁻3 during prediction).