Nanomaterials with amorphous surface have attracted significant attention in the oxygen evolution reaction (OER), which still needs further investigations. In this work, we developed a novel Salt-regulated confinement loading method to prepare amorphous Mn3CoOx support confined FeO microcrystallites at a relatively low-temperature (623 K). The confined FeO microcrystallites showed strong interfacial electronic interactions with Mn3CoOx matrix (abundant defect sites and flexible local environments), enabling efficient charge transfer and enhanced intermediate stabilization for efficient OER in acidic media. The FeO/Mn3CoOx exhibits remarkable OER performance, with a low overpotential of 252 mV@10 mA cm-2 with a significantly lower Tafel slope of 79 mV dec-1, outperforming the commercial IrO2 (∼ 290 mV@10 mA cm-2). Mechanistic studies reveal that the incorporation of FeO microcrystallites, as electron reservoirs to stabilize high-valence intermediates and facilitate continuous turnover, induces a synergistic transition from a purely lattice oxygen-mediated mechanism (LOM) to a dual LOM and oxygen pathway mechanism (OPM).These results are well corroborated by in situ attenuated total reflection surface-enhanced infrared spectroscopy, differential electrochemical mass spectrometry, and density functional theory calculations. Our work provides a robust strategy to design amorphous, non-precious-metal OER catalysts capable of stable operation in acidic media, offering a scalable route toward efficient hydrogen production.

Regarding low-grade waste heat harvesting, establishing sustainable ionic thermoelectric (i-TE) materials, especially negative-thermopower (n-type) systems has become imperative. Here we report that natural balsa wood can be converted into a n-type i-TE material with an ionic thermopower of -25.4 mV K- 1 by treating with CuCl2. We find that the spatial heterogeneity of wood components governs heterogeneous ion distribution, resulting in decoupled anion-cation thermodiffusion. Specifically, Cu2+ ions are preferentially confined within hemicellulose and lignin domains, whereas aligned amorphous cellulose nanochannels facilitate Cl- ion thermodiffusion toward the cold side, thereby enabling an n-type thermoelectric response. Motivated by these findings, a deep eutectic solvent (DES)-assisted fibrillation-quaternization strategy was developed to construct iTE quaternized wood with expanded cellulose nanochannels and preserved lignin cation-binding sites. The optimized i-TE QW-12 exhibits an ultrahigh thermopower of -32.5 mV K- 1 together with an ionic conductivity of 11.5 mS cm- 1, and this strategy is applicable to multiple wood species. Finally, the facile processability of wood enables the development of i-TE QW-12 for self-powered temperature sensors and scalable low-grade heatharvesting devices. Deep insights into the wood component-regulated ion decoupling behavior will greatly forward the rational design of sustainable high-performance n-type i-TE materials.

Iridium-based materials are less studied in proton exchange membrane water electrolyzers (PEMWEs), which are crucial for the generation of green hydrogen, due to their rarity and high cost. Herein, doping Cr with cobalt oxide resulted in rich oxygen vacancies with the Co2+/Cr3+redox couples and surface hydroxyl groups, which considerably enhance the capacity of the material to adsorb and activate oxygen intermediates. Due to its structural and electrical characteristics, CrCo8Ox has proven to be a stable and effective catalyst for acidic oxygen evolution reaction (OER) and high-performance PEMWEs applications. A high current density of 100 mA & centerdot;cm-2 was attained by the CrCo8Ox anode catalyst and maintained for 130 h, whereas a current density of 300 mA & centerdot;cm-2 was maintained for 20 h. In situ Fourier transform infrared (FT-IR) spectroscopy combined with density functional theory (DFT) calculations corroborate the oxide path mechanism (OPM) over pristine Co3O4 rather than the associative electron mechanism (AEM) over Cr-doped CrCo8Ox composites. Such outstanding results indicate a bright future for industrial deployment and provide broad recommendations for developing PEMWEs with high efficiency.

Abstract Covalent organic frameworks (COFs) are increasingly recognized as promising crystalline platforms for solar-driven H2 evolution because of their unique architectures, extended conjugation characteristics, adjustable pore environments, and structural regularity. Nevertheless, unmodified frameworks generally exhibit inadequate photocatalytic functionality and rapid recombination of photoinduced charge carriers, limiting their performance during H2 evolution processes. To address these limitations, extensive investigations have explored the incorporation of metallic entities into COF networks to improve light absorption, carrier mobility, interfacial redox behavior, and surface catalytic dynamics. Despite rapid developments in this area, an integrated understanding linking metallic incorporation approaches with H2 evolution activity remains insufficient. This review therefore provides a comprehensive overview connecting the structural characteristics and catalytic functions of metal-containing COF systems for photocatalytic H2 evolution. The fundamental chemistry and framework features of COFs are first introduced, followed by representative methodologies for incorporating metallic species and their corresponding functional effects in regulating light absorption, charge separation, proton reduction, and H2 evolution kinetics. Finally, future research directions toward constructing highly efficient and durable COF-based photocatalysts for sustainable H2 evolution are critically highlighted.

ABSTRACT Nanomaterials with amorphous surface have attracted significant attention in the oxygen evolution reaction (OER), which still needs further investigations. In this work, we developed a novel Salt‐regulated confinement loading method to prepare amorphous Mn 3 CoO x support confined FeO microcrystallites at a relatively low‐temperature (623 K). The confined FeO microcrystallites showed strong interfacial electronic interactions with Mn 3 CoO x matrix (abundant defect sites and flexible local environments), enabling efficient charge transfer and enhanced intermediate stabilization for efficient OER in acidic media. The FeO/Mn 3 CoO x exhibits remarkable OER performance, with a low overpotential of 252 mV@10 mA cm −2 with a significantly lower Tafel slope of 79 mV dec −1 , outperforming the commercial IrO 2 (∼ 290 mV@10 mA cm −2 ). Mechanistic studies reveal that the incorporation of FeO microcrystallites, as electron reservoirs to stabilize high‐valence intermediates and facilitate continuous turnover, induces a synergistic transition from a purely lattice oxygen‐mediated mechanism (LOM) to a dual LOM and oxygen pathway mechanism (OPM).These results are well corroborated by in situ attenuated total reflection surface‐enhanced infrared spectroscopy, differential electrochemical mass spectrometry, and density functional theory calculations. Our work provides a robust strategy to design amorphous, non‐precious‐metal OER catalysts capable of stable operation in acidic media, offering a scalable route toward efficient hydrogen production.

Nickel-based superalloys are extensively employed in critical high-temperature aerospace applications owing to their exceptional high-temperature strength, oxidation resistance, and creep resistance. However, they are also regarded as typical difficult-to-machine materials. Abrasive waterjet (AWJ) milling, as a non-traditional machining technology, has been recognized as an effective solution for processing nickel-based superalloys, offering distinct advantages such as the absence of thermal damage, high material removal rates, and the capability to process difficult-to-machine materials. Since its introduction, AWJ milling has achieved substantial advancements in theory, practice, and numerical simulation. To support further research in this field, this study provides a systematic review and in-depth analysis of existing research on AWJ milling, with a particular focus on milling depth control, machined surface integrity, and finite-element-based investigations into AWJ milling mechanisms. These studies collectively offer essential theoretical foundations and technical guidance for future development. Finally, the current challenges associated with AWJ milling of nickel-based superalloys are summarized, and potential future research directions are proposed.

Investigation of ion implantation-induced damage is critical for regulating the defect states of GaN. To explore the effect of Mg ion implantation dose on the structure and defects of GaN, MOCVD-grown GaN samples implanted at different doses were characterized. The results indicate that ion implantation induces lattice disorder in GaN, causing periodic distortion of its c-axis lattice constant. The implanted defects exhibit significant interactions. With increasing ion dose, leveraging GaN's highly efficient dynamic annealing effect, point defects preferentially nucleate on basal planes to form two-dimensional clusters. These clusters act as efficient absorbers for point defects. TEM observations revealed defect structures such as dislocation loops, stacking faults, and vacancy clusters within the samples. However, even at the highest dose of 6 & times; 1015 cm- 2 in this experiment, GaN has not completely amorphized, which is attributed to the efficient dynamic annealing effect. This study clarifies the intrinsic mechanisms of lattice changes and defect interactions in GaN under Mg ion implantation, providing experimental support for the regulation of ion implantation doping processes and defect control.

This study introduces an advanced Ir single-atom catalyst on MnCoOx clusters (Ir-SA-MnCoOx) for OER in acidic media. Ir-SA-MnCoOx exhibits exceptional OER activity and stability, which stems from several key factors: (i) high-valence Ir (Ir+>4) creating oxygen vacancies as active sites; (ii) strengthened Ir-O bonds and enhanced stability in acid; and (iii) optimized reaction pathway by the synergistic interaction among Ir, Mn, and Co. Ir-SA-MnCoOx exhibits a low overpotential of 186 mV at 10 mA cm(-2), outperforming IrB (260 mV at 10 mA cm(-2)). Its mass activity reaches 3099.9 A g(Ir)(-1) at 420 mV, 14.2 times higher than IrB. In PEM water electrolysis, it shows excellent durability for over 170 h at 1 A cm(-2). In situ FT-IR spectroscopy and DFT calculations confirm the oxide path mechanism (OPM) over Ir-SA-MnCoOx, revealing a moderate metal d-band center, rather than the associative electron mechanism over MnCoOx carriers. This work highlights the potential of atomic-level tuning for high-performance electrocatalysts, offering new insights for sustainable hydrogen production.

Zinc electrolyte crystallization sediment (ZECS) generated in the zinc hydrometallugy industry contains valuable metals of strontium (Sr), manganese (Mn), and zinc (Zn), which has economical value but poses potential detrimental to the environment. However, the extraction and recovery of Sr is extremely difficult due to the thermodynamically stable Ca and Sr sulfate cocrystallization structure in ZECS. The destruction of refractory sulfate cocrystallization structure is a prerequisite for Sr extraction, and the carbothermal reduction roasting method is demonstrated to be efficient for the phase reconstruction. In this study, a stepwise Sr, Mn, and Zn recovery process from ZECS via carbothermal reduction roasting-acid leaching-selective precipitation-multistage extraction was proposed. In the reduction roasting procedure, all the sulfates including CaSO4, 4 , SrSO4, 4 , and Ca 0.7 Sr 0.3 SO 4 are reduced to soluble sulfides. Meanwhile, most MnO2 2 is converted to a low-valence Mn product (MnO) that is soluble in acid, and the reduced Zn (g) is volatilized which can be collected from the flue dust. In the acid leaching procedure, the leaching efficiencies of Sr, Ca, and Mn are as high as 97.34%, 97.44%, and 95.49% respectively, while 99.50% Si in the form of silica is enriched in the leaching residue. After that, high-purity Sr solution was obtained after selective precipitation for Mn removal and D2EHPA multistage extraction for Ca removal. 97.41% Mn in the leaching solution is precipitated by adjusting the pH value to 9.5 with NaOH solution. After four-stage extraction, 79.60% Sr and only 0.35% Ca are retained in the aqueous phase. The purified solution contains 2.88 g/L Sr, 0.052 g/L Ca, and 0.014 g/L Mn, which can be used to prepare industrial SrCO3 3 product via the carbonation operation. Thermodynamic behavior and reduction roasting reconstruction mechanism of Ca and Sr sulfate cocrystallization structure in ZECS were discussed in this work. The distributions of main metal elements (Sr, Ca, Mn, and Zn) in ZECS during the carbothermal reduction roasting-acid leaching- selective precipitation-multistage extraction process were also systematically studied.

With the rapid expansion of China's alumina industry and the depletion of high-grade bauxite, efficient utilization of low-grade diasporic bauxite has become a critical challenge. This study proposes an innovative method combining sodium nitrate activation roasting with low-alkali leaching to enhance alumina extraction. Activation roasting at moderate to high temperatures significantly improves bauxite solubility, and subsequent leaching with a low-concentration caustic soda solution (Nk = 160 g/L) enhances alumina dissolution. XRD analysis reveals that sodium nitrate promotes phase transformations, converting diaspore and kaolinite into Na2-xAl2-xSixO4 at 700-1000 degrees C. Increasing the roasting temperature within the 700-1000 degrees C range lower the x value in Na2-xAl2-xSixO4, but also inhibits its decomposition of Na2-xAl2-xSixO4 into NaAlO2 and Na2SiO3. At an aluminum-to-sodium nitrate molar ratio of 1 (N/A = 1), NaAlO2, a highly soluble phase, forms predominantly at 750 degrees C. However, at 750 degrees C excessive roasting time or sodium nitrate leads to Na2-xAl2-xSixO4 with increased x, reducing solubility. Through systematic optimization, we determined the ideal conditions: roasting at 750 degrees C for 2 h, followed by leaching at 270 degrees C for 60 min with a solid-liquid ratio of 300 g/L. This optimized process achieved an exceptional alumina leaching rate exceeding 75 % from bauxite with an initial alumina-to-silica ratio (A/S) ratio of 3.57, while maintaining silica dissolution at a minimal 0.59 %. The resulting red mud had an A/S ratio of 0.88, significantly lower than that of the Bayer process. This methodology not only enhances the leaching rate of alumina from low-grade bauxite but also provides a sustainable solution for the comprehensive utilization of lowgrade bauxite resources.

Neutrinoless double-beta decay (0 νββ ) experiments constitute a pivotal probe for elucidating the characteristics of neutrinos and further discovering new physics. Compared to the neutron transmutation-doped germanium thermistors used in 0 νββ experiments such as CUORE, transition edge sensors (TESs) theoretically have a relatively faster response time and higher energy resolution. These make TES detectors good choice for next generation 0 νββ experiments. In this paper, AlMn alloy superconducting films, the main components of TES, were prepared and studied. The relationship between critical temperature ( T_c ) and annealing temperature was established, and the impact of magnetic field on T_c was tested. The experimental results demonstrate that the T_c of AlMn film can be tuned in the required range of 10–20 mK by using the above methods, which is a key step for the application of AlMn TES in 0 νββ experiment. In the test range, the T_c of AlMn film is sensitive to out-of-plane magnetic field but not to the in-plane magnetic field. Furthermore, we find that a higher annealing temperature results in a more uniform distribution of Mn ions in depth, which opens a new avenue for elucidating the underlying mechanism for tuning T_c .

The electroreduction of nitrate (NO3-) for sustainable ammonia (NH3) production has recently emerged as a green process to solve water contamination and produce valuable chemicals. In this study, we developed Ni6@CuFe-LDH composites comprising tiara Ni6(SC2H4COOH)12 (Ni6) clusters anchored on the edges of 2D CuFe-LDH (LDH: layered double hydroxides) nanosheets via electrostatic interactions. The Ni6@CuFe-LDH catalyst exhibits high electrochemical performance in nitrate reduction reaction (NO3RR). Specifically, the Ni6@CuFe-LDH gives rise to an excellent faradaic efficiency of ∼97%, significantly surpassing the ∼73% FE of the pristine CuFe-LDH, with the NH3 productivity (0.91 mmol mg-1 h-1) being similar to that of the CuFe-LDH. Mechanistic studies reveal that the superior electrocatalysis of Ni6-based catalysts is primarily due to the synergistic interaction between Ni6 clusters and CuFe-LDH, which alters the rate-determining step (RDS) of the desorption of *NH3 species (for CuFe-LDH) to the *NO3 → *NO2 step (for Ni6@CuFe-LDH); this is corroborated by the control experiments of NO2RR, in situ Raman and infrared spectroscopies, and computational approaches. In all, these efforts push forward the NO3RR research to study the structure-property relationships from the micro/nano-level to the precise atomic-level.

Researchers usually detect insider threats by analyzing user behavior. The time information of user behavior is an important concern in internal threat detection. Existing works on insider threat detection fail to make full use of the time information, which leads to their poor detection performance. In this paper, we propose a novel behavioral feature extraction scheme: we implicitly encode absolute time information in the behavioral feature sequences and use a feature sequence construction method taking covariance into account to make our scheme adaptive to users. We select Stacked Bidirectional LSTM and Feedforward Neural Network to build a deep learning-based insider threat detection model: Behavior Rhythm Insider Threat Detection (BRITD). BRITD is universally applicable to various insider threat scenarios, and it has good insider threat detection performance: it achieves an AUC of 0.9730 and a precision of 0.8072 with the CMU CERT dataset, which exceeds all baselines.

α -W thin films are widely used in superconducting transition edge sensors due to their extremely low transition temperature and weak electron–phonon coupling. However, the influence of annealing and substrate temperatures on thin film performance has not been fully understood, nor has the relationship between microstructure and thin film performance. In this study, we investigate the changes in grain size, resistivity, film stress, and transition temperature of the film by varying the annealing and substrate temperatures. Microstructure showed that annealing contributed to grain growth. With the increase in annealing temperature, the resistivity of the film decreased and the compressive stress was relieved. The minimum transition temperature reached 28.7 mK at an annealing temperature of 470 ^∘ C. In addition, the GIXRD results showed that the preferred orientation of the films changed from (110) to (211) with the increase in the substrate temperature. 100 ^∘C-230 ^∘ C favorite to reduce film resistivity and transition temperature, and to relieve film compressive stress.

The green synthesis and mass production of cost-effective substrates with high phosphorus adsorption capacity and good application feasibility is crucial for the efficient removal and recovering of phosphorus from aquatic environments. In this study, eco-friendly Magnesium-based Cementitious Material (MCM) was prepared and its phosphate adsorption performance was thoroughly investigated. The MCM exhibited a significant phosphorus adsorption capacity of 42 mg/g. Phosphate adsorption on MCM was well fitted by the Redlich-Langmuir isotherm and pseudo first-order models. The intra-particle diffusion model indicated that phosphate adsorption was governed by surface reactions and diffusion processes. Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and X-ray Photoelectron Spectroscopy analyses revealed that phosphate removal mechanisms involved electrostatic attraction, inner sphere complexation, ligand exchange, crystal nucleation and crystallization, and precipitation. Density Functional Theory (DFT) calculations confirmed that the -OH groups provided by Mg(OH)2 and Mg3(OH)5Cl & sdot;4H2O were active sites capable of chemically adsorbing HPO2-4 anions, forming surface complexes. In addition, plant available Mg-P precipitates were observed on the surface of MCM, indicating that postsorption MCM might be used as phosphate and magnesium fertilizer. MCM showed great application prospects with the advantages of being non-toxic, economical, and easy to prepare.

Contrastive self-supervised learning (CSL) based on instance discrimination typically attracts positive samples while repelling negatives to learn representations with pre-defined binary self-supervision. However, vanilla CSL is inadequate in modeling sophisticated instance relations, limiting the learned model to retain fine semantic structure. On the one hand, samples with the same semantic category are inevitably pushed away as negatives. On the other hand, differences among samples cannot be captured. In this paper, we present relation-aware contrastive self-supervised learning (ReCo) to integrate instance relations, i.e., global distribution relation and local interpolation relation, into the CSL framework in a plug-and-play fashion. Specifically, we align similarity distributions calculated between the positive anchor views and the negatives at the global level to exploit diverse similarity relations among instances. Local-level interpolation consistency between the pixel space and the feature space is applied to quantitatively model the feature differences of samples with distinct apparent similarities. Through explicitly instance relation modeling, our ReCo avoids irrationally pushing away semantically identical samples and carves a well-structured feature space. Extensive experiments conducted on commonly used benchmarks justify that our ReCo consistently gains remarkable performance improvements.

Stainless steel has a broad application in various areas of the national economy, while a mass of stainless-steel scraps is generated during the abrasive machining process. These scraps are rich in metallic ingredients such as Fe, Ni, and Cr, which shows an extremely comprehensive recovery value. Due to good plasticity and ductility, the stainless-steel scrapsStainless-steel scraps are hard to grind to fine particlesParticle. The low dissolution efficiency of coarse particlesParticle limits the efficient utilization of stainless-steel scrapsStainless-steel scraps. This work provides a clean and intensifyingIntensifying acid leachingAcid leaching method of Fe, Ni, and Cr from stainless-steel scrapsStainless-steel scraps via ultrasonic treatment. Under the conditions of ultrasound power of 540W, H2SO4 concentration of 3 mol/L, leachingLeaching time of 15 min, temperature of 30 °C, and liquid-to-solid ratio of 20:1, the leachingLeaching efficiencies of Fe, Ni, and Cr are 99.93, 99.91, and 99.92