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Recently, the development of new materials and devices has become the main research focus in the field of energy. Supercapacitors (SCs) have attracted significant attention due to their high power density, fast charge/discharge rate, and excellent cycling stability. With a lamellar structure, 2D transition metal dichalcogenides (2D TMDs) emerge as electrode materials for SCs. Although many 2D TMDs with excellent energy storage capability have been reported, further optimization of electrode materials and devices is still needed for competitive electrochemical performance. Previous reviews have focused on the performance of 2D TMDs as electrode materials in SCs, especially on their modification. Herein, the effects of element doping, morphology, structure and phase, composite, hybrid configuration, and electrolyte are emphatically discussed on the overall performance of 2D TMDs‐based SCs from the perspective of device optimization. Finally, the opportunities and challenges of 2D TMDs‐based SCs in the field are highlighted, and personal perspectives on methods and ideas for high‐performance energy storage devices are provided. [ABSTRACT FROM AUTHOR]

A comprehensive investigation of metal–alloy induced crystallization (MAIC) of amorphous silicon (a-Si) is presented. The crystallization processes in three microstructurally principally different, representative types of metal(-alloy)/a-Si systems, Alx(Ge1−x)/a-Si, AgxAl1−x/a-Si, and AlxZn1−x/a-Si, have been monitored by in situ heating x-ray diffraction (XRD) from 25 °C up to 475 °C, until crystallization of a-Si was completed. The obtained experimental results have been systematically compared to predictions obtained by applications of thermodynamic models based on calculations of interface and crystallization energies for the determination of so-called critical thicknesses and initial crystallization temperatures. From the investigation of the MAIC processes in the metal–alloy/a-Si systems, it has been demonstrated that the crystallization temperature and the crystallization kinetics can be well tailored and optimized by controlling the composition and microstructure of the metal alloys. This research, on the one hand, exposes the fundamental, principal role of interface thermodynamics on the crystallization processes and, on the other hand, opens new possibilities for the growth of technologically important, pure, crystalline semiconductor thin films at very low temperatures, as compared to the crystallization temperature of isolated, bulk semiconductor materials. [ABSTRACT FROM AUTHOR]

Despite the expectation on transition‐metal phosphides as precious‐metal‐free electrocatalysts, the reported performance of these materials still necessitates further improvement. Ingenious regulations of both geometric and electronic structure have been proposed as an effective approach to boost their electrocatalytic properties. In this regard, the self‐supported V doped CoP nanowires on nickel foam are prepared to accommodate both optimized electronic structure and desired nanostructure, which enable large surface area, abundant active sites exposure, low charge transfer resistance, as well as favorable H* adsorption. As for the alkaline hydrogen evolution, it only requires a lower potential of 79 mV and 125 mV to drive 10 mA ⋅ cm−2 and 100 mA ⋅ cm−2 current with a Tafel slope of 47.41 mV ⋅ dec−1, which prevails over commercial Pt/C catalysts. The catalyst also exhibits excellent durability to retain activity unchanged for more than 16 h. Such a simple and convenient strategy by electronic tuning and structure design provides a new avenue toward the exploration of efficient electrocatalysts. [ABSTRACT FROM AUTHOR]

This research utilizes both single crystal and polycrystalline models to probe the fatigue crack propagation mechanism in pure silver via molecular dynamics (MD) simulations. A comprehensive validation approach at both micro and macro scales, incorporating transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and compact tension (CT) specimen fatigue testing, is developed to verify the reliability of simulation models and results. Simulation findings indicate that the initial crack orientation significantly influences crack propagation. As the crack advances within the crystal, two primary crack propagation mechanisms are discerned: (1) nano-voids appear at the crack tip, and the crack propagates by continuously aggregating with the nano-voids ahead; (2) the formation of Stair-rod dislocations and V-shape stacking faults due to dislocation reactions and slip band movements impedes crack propagation, accompanied by the dislocation reaction of Shockley partial dislocations ( 1 6 <112>) generating Hirth dislocations ( 1 6 <110>). The dislocation reaction is verified through the dislocation analysis of the crack tip area of the CT specimen after fatigue experiment by using TEM. In addition, the results of this study show that the angle between the direction of crack propagation and the grain boundary affects the fatigue crack propagation, e.g. when the angle is less than 60°, the crack rapidly propagates along the grain boundary. The orientation distribution function (ODF) results of EBSD can verify that the polycrystalline model containing 30 grains is a reliable model for the MD simulation of behavior of the crack tip of CT specimen. Lastly, the Paris law constants for pure silver are determined as m = 3.72 and lg C = − 10.77, providing a reference for the fatigue analysis and life prediction of silver components or silver soldering pots in engineering applications. [ABSTRACT FROM AUTHOR]

The crystal phase plays an important role in controlling the properties of a nanomaterial; however, it is a great challenge to obtain a nanomaterial with high purity of the metastable phase. For instance, the large‐scale synthesis of the metallic phase MoS2 (1T‐MoS2) is important for enhancing electrocatalytic reaction, but it can only be obtained under harsh conditions. Herein, a spatially confined template method is proposed to synthesize high phase‐purity MoS2 with a 1T content of 83 %. Moreover, both the confined space and the structure of template will affect the purity of 1T‐MoS2; in this case, this approach was extended to other similar spatially confined templates to obtain the high‐purity material. The obtained ultrathin nanosheets exhibit good electrocatalytic activity and excellent stability in the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

The crystal phase plays an important role in controlling the properties of a nanomaterial; however, it is a great challenge to obtain a nanomaterial with high purity of the metastable phase. For instance, the large‐scale synthesis of the metallic phase MoS2 (1T‐MoS2) is important for enhancing electrocatalytic reaction, but it can only be obtained under harsh conditions. Herein, a spatially confined template method is proposed to synthesize high phase‐purity MoS2 with a 1T content of 83 %. Moreover, both the confined space and the structure of template will affect the purity of 1T‐MoS2; in this case, this approach was extended to other similar spatially confined templates to obtain the high‐purity material. The obtained ultrathin nanosheets exhibit good electrocatalytic activity and excellent stability in the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Tuning the electrocatalytic selectivity and long‐term stability for industrially significant, yet reactively unfavorable products, remains a challenge in oxygen reduction. Herein, the Au/TiO2 catalysts with strong metal–support interactions (SMSI) are designed and synthesized through an in situ auto‐reduction of Au‐modified Ti‐MOF. Highly dispersed ultra‐low loading of Au NPs strongly capsulated in porous TiO2 substrate, together with conductive carbon derivated from MOFs, enables Au/TiO2 electrocatalysts to achieve excellent H2O2 electrosynthesis through the two‐electron oxygen reduction reaction (2e ORR). Au(1.0)/TiO2 (0.52 wt% Au loading) exhibited a high selectivity of 90%, a remarkable Faradaic efficiency of 98%, and 72.2 mg L−1 h−1 H2O2 production. Highly dispersed Au NPs promote active site exposure, while the conductive carbon and the porous superstructure enhance mass diffusion. Notably, the SMSI between Au NPs and TiO2 substrate leads to superb stability (over 168 h) of the electrocatalysts, as it ensures continuous electronic interactions. Experimental characterizations and density functional theory (DFT) simulations further revealed that the SMSI effect medicates the activation of the *OOH intermediate formation and the d‐band center, which are conductive to 2e ORR. Moreover, this strategy provides a potential way toward high‐performance electrocatalysts in flow system devices for continuously purifying sewage and chemical bleaching in extreme environments. [ABSTRACT FROM AUTHOR]

Precisely carving of multi‐shelled manganese–cobalt oxide hollow dodecahedra (Co/Mn‐HD) with shell number up to three is achieved by a controlled calcination of the Mn‐doped zeolitic imidazolate framework ZIF‐67 precursor (Co/Mn‐ZIF). The unique multi‐shelled and polycrystalline structure not only provides a very large electrochemically active surface area (EASA), but also enhances the structural stability of the material. The residual C and N in the final structures might aid stability and increase their conductivity. When used in alkaline rechargeable battery, the triple‐shelled Co/Mn‐HD exhibits high electrochemical performance, reversible capacity (331.94 mAh g−1 at 1 Ag−1), rate performance (88 % of the capacity can be retained with a 20‐fold increase in current density), and cycling stability (96 % retention over 2000 cycles). Me, my shell, and I: A controlled continuous two‐step calcination of the Mn‐doped zeolitic imidazolate framework ZIF‐67 precursor (Co/Mn‐ZIF) gives triple‐shelled manganese–cobalt oxide hollow dodecahedra (Co/Mn‐HD). Co/Mn‐HD has promising electrochemical performance for rechargeable alkaline batteries. [ABSTRACT FROM AUTHOR]

Precisely carving of multi‐shelled manganese–cobalt oxide hollow dodecahedra (Co/Mn‐HD) with shell number up to three is achieved by a controlled calcination of the Mn‐doped zeolitic imidazolate framework ZIF‐67 precursor (Co/Mn‐ZIF). The unique multi‐shelled and polycrystalline structure not only provides a very large electrochemically active surface area (EASA), but also enhances the structural stability of the material. The residual C and N in the final structures might aid stability and increase their conductivity. When used in alkaline rechargeable battery, the triple‐shelled Co/Mn‐HD exhibits high electrochemical performance, reversible capacity (331.94 mAh g−1 at 1 Ag−1), rate performance (88 % of the capacity can be retained with a 20‐fold increase in current density), and cycling stability (96 % retention over 2000 cycles). [ABSTRACT FROM AUTHOR]

Nanowires are major building components for nanotechnology. The growth and the assembly of nanowires are often complicated and expensive, which has impeded practical applications of such nanotechnology. This work discloses a Vapor-Defect-Solid (VDS) mechanism for growth of nanowall networks (NanoNets), by exploring a spontaneous interaction of vapor and defect networks in polycrystalline materials. A kinetic model analysis of the precondition and the characteristics of the VDS growth process is presented. The VDS growth mechanism allows straightforward, fast growth of two-dimensional NanoNets at near room temperature from vapor sources with a very high production yield, and thus holds potential as a general route for large-area production of NanoNets at a reduced cost. The VDS growth mechanism further allows exploration of fundamental knowledge of grain-boundary networks in nanocrystalline materials, and opens new avenues for grain-boundary engineering. [ABSTRACT FROM AUTHOR]

Industrial wastewater containing both organic and inorganic pollutants is being generated all the time. Efficient materials are highly needed to purify the polluted water. Thus, a hierarchical structured α-Fe 2 O 3 with excellent adsorptive property has been synthesized by using a facile hydrothermal method. It can be prepared in macroscopic quantity. The as-synthesized α-Fe 2 O 3 with silkworm cocoon-like morphology shows high efficiency in adsorbing Congo red (CR), Methyl orange (MO) and Cr(VI). The removal efficiency of CR, MO and Cr(VI) can reach 99.2%, 83.9% and 100% under appropriate conditions. Besides, this α-Fe 2 O 3 shows high adsorptive ability for mixed CR and Cr(VI) in aqueous solution and the final removal rates can reach 94.7% and 97.9%, respectively. The adsorption kinetics fits well with the pseudo-second-order kinetic model. The results indicate that the product may find potential application in purification of wastewater containing both organic and inorganic pollutants. [ABSTRACT FROM AUTHOR]

Graphical abstract Cobalt hollow nanospheres are successfully synthesized by using the solvothermal method. The morphology of the cobalt hollow nanospheres can be regulated by adjusting the original ethylenediamine/ethanol volume ratio, reaction time and temperature. Impressively, the magnetic property study reveals that the coercivity of the as-synthesized cobalt hollow nanospheres is much enhanced compared with that of bulk cobalt materials. Moreover, the as-synthesized cobalt hollow nanospheres, CoPtHS and CoHS-rGO show highly catalytic activities for the hydrogen generation from ammonia borane (AB) hydrolysis. Abstract Size tunable cobalt hollow nanospheres with high catalytic activity for the ammonia borane (AB) hydrolysis have been synthesized by using the solvothermal method. The complexation between Co2+ and ethylenediamine is observed to be critical for the formation of the cobalt hollow nanospherical structure. The morphology of the cobalt hollow nanospheres can be regulated by adjusting the original ethylenediamine/ethanol volume ratio, reaction time and temperature. Impressively, the magnetic property study reveals that the coercivity of the as-synthesized cobalt hollow nanospheres is much enhanced compared with that of bulk cobalt materials. Meanwhile, Co/Pt bimetal hollow nanospheres (CoPtHS) and graphene-cobalt hollow composite nanospheres (CoHS-rGO) have also been explored. In comparison with the cobalt hollow nanospheres, both the CoPtHS and CoHS-rGO show higher catalytic activities and better repeatability for the catalytic hydrogen generation from AB hydrolysis. Moreover, it is noted that these catalysts could be recycled by using the magnetic separation method. [ABSTRACT FROM AUTHOR]

The thermal crystallization of heavily hydrogenated, amorphous Ge ( a-Ge :H) and ultra-pure amorphous Ge ( a-Ge ) thin films was investigated, on a comparative basis, by X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) performed during in situ heating. It was found that the crystallization process in a-Ge :H is pronouncedly retarded, due to the initial presence of hydrogen-induced nano voids . The crystallization of a-Ge :H initiates only after considerable reduction of the amount of nano voids in the amorphous matrix by thermally induced coarsening of the nano voids leading to nano pores in the a-Ge :H. Such retarded crystallization leads to the formation of nanocrystalline , porous Ge with nanocrystal sizes below 20 nm, in contrast with the fast formation of very large-grained (grain sizes of hundreds of nanometer) polycrystalline Ge upon thermal crystallization of pure a-Ge . [ABSTRACT FROM AUTHOR]

Intelligent agriculture has become the development trend of agriculture in the future, and it has a wide range of research and application scenarios. Using machine learning to complete basic tasks for people has become a reality, and this ability is also used in machine vision. In order to save the time in the fruit picking process and reduce the cost of labor, the robot is used to achieve the automatic picking in the orchard environment. Cherry target detection algorithms based on deep learning are proposed to identify and pick cherries. However, most of the existing methods are aimed at relatively sparse fruits and cannot solve the detection problem of small and dense fruits. In this paper, we propose a cherry detection model based on YOLOv5s. First, the shallow feature information is enhanced by convolving the feature maps sampled by two times down in BackBone layer of the original network model to the input end of the second and third CSP modules. In addition, the depth of CSP module is adjusted and RFB module is added in feature extraction stage to enhance feature extraction capability. Finally, Soft- Non-Maximum Suppression (Soft-NMS) is used to minimize the target loss caused by occlusion. We test the performance of the model, and the results show that the improved YOLOv5s-cherry model has the best detection performance for small and dense cherry detection, which is conducive to intelligent picking. [ABSTRACT FROM AUTHOR]

During thermal oxidation of binary amorphous Al x Zr 1− x solid solutions over wide alloy-composition (0.26 ⩽ x ⩽ 0.68) and oxidation-temperature (350–560 °C) ranges, a single amorphous ternary oxide phase of well-defined stoichiometry, (Al 0.33 Zr 0.67 )O 1.83 , emerges. The composition of this unexpectedly stoichiometric ternary amorphous oxide phase, that develops instead of the crystalline oxide phases Al 2 O 3 and ZrO 2 , under conditions far away from genuine thermodynamic equilibrium, is governed by thermodynamics, as demonstrated by thermodynamic assessment, adopting the amorphous (Al 0.33 Zr 0.67 )O 1.83 phase as a supercooled liquid oxide–oxide (Al 2 O 3 –ZrO 2 ) solution phase. [ABSTRACT FROM AUTHOR]

Abstract: Al-induced crystallization (AIC) of amorphous Si x Ge1−x (a-Si x Ge1−x ) solid solutions, with compositions over the entire range of the isomorphous Si–Ge system, was investigated. The crystallization progress was monitored in detail, at low temperatures from 150 to , by in situ X-ray diffraction while gradually increasing the annealing temperature until crystallization was completed, allowing for an evaluation of the crystallization kinetics. The formation of single-phase crystalline Si x Ge1−x solid solutions upon AIC of a-Si x Ge1−x (0 x 1) was observed at all annealing temperatures. Concentration–depth profiling by Auger electron spectroscopy provided a detailed insight into the diffusion processes occurring in the early stage of the low-temperature AIC process and the intriguing phenomenon of layer exchange of the Al and a-Si x Ge1−x sublayers. On the basis of evaluation of the Si and Ge diffusion coefficients, the results suggest that, upon AIC, both Si and Ge atoms diffuse at comparable rates into the Al layer in the low temperature range investigated. The degree of completeness of the layer-exchange process after full crystallization is a function of the a-Si x Ge1−x composition; complete layer exchange occurs for all Al/a-Si x Ge1−x specimens containing more than 27at.% Si. [Copyright &y& Elsevier]

YO nanoplates composed of nanoparticles with both low-energy and high-energy facets exposed have been synthesized via a facile hydrothermal approach and subsequent calcination treatment. The pH value of the reaction solution was observed to play a key role for the formation and even the size- and thickness-control of the nanoplate-like precursor. On calcination at 900 °C for 4 h, the precursors were decomposed into YO with well-maintained flake-like morphology. These YO nanoplates showed obviously improved catalytic CO oxidation activities than commercial and synthesized nanorod YO. Under the UV excitation, flake-like YO:Eu phosphors exhibit strong red photoluminescence emissions, and nanoplates with the reaction temperature of 180 °C, reaction time of 36 h, as well as pH value of 7.4 showed the strongest photoluminescence intensity. This precursor-induced path provided not only a meaningful reference for dimension and size controlled synthesis, but also a potential way to achieve high-active facet exposed materials. [ABSTRACT FROM AUTHOR]

Functionalization of thin-film heterostructures on the basis of their electrical, optical and magnetic properties, requires precise control of the film stresses that develop during the growth process. By using real-time in situ stress measurements, the present study reveals strikingly that the in-plane film stress oscillates with increasing film thickness at the initial stage of epitaxial Al(lll) film growth on a Si(lll)-√3 X √3-A1 surface, with a periodicity of 2 times the Fermi wavelength of bulk Al and a stress variation from maximum to minimum as large as 100 MPa. Such macroscopic stress oscillations are shown to be caused by quantum confinement of the free electrons in the ultrathin epitaxial metal film. The amplitude, period, and phase of the observed stress oscillations are consistent with predictions based on the free electron model and continuum elasticity. [ABSTRACT FROM AUTHOR]

Triggering the lattice oxygen oxidation mechanism is crucial for improving oxygen evolution reaction (OER) performance, because it could bypass the scaling relation limitation associated with the conventional adsorbate evolution mechanism through the direct formation of oxygen–oxygen bond. High‐valence transition metal sites are favorable for activating the lattice oxygen, but the deep oxidation of pre‐catalysts suffers from a high thermodynamic barrier. Here, taking advantage of the Jahn–Teller (J–T) distortion induced structural instability, we incorporate high‐spin Mn3+ (t2g3eg1 ${{t}_{2g}^{3}{e}_{g}^{1}}$) dopant into Co4N. Mn dopants enable a surface structural transformation from Co4N to CoOOH, and finally to CoO2, as observed by various in situ spectroscopic investigations. Furthermore, the reconstructed surface on Mn‐doped Co4N triggers the lattice oxygen activation, as evidenced experimentally by pH‐dependent OER, tetramethylammonium cation adsorption and online electrochemical mass spectrometry measurements of 18O‐labelled catalysts. In general, this work not only offers the introducing J–T effect approach to regulate the structural transition, but also provides an understanding about the influence of the catalyst's electronic configuration on determining the reaction route, which may inspire the design of more efficient catalysts with activated lattice oxygen. [ABSTRACT FROM AUTHOR]

Triggering the lattice oxygen oxidation mechanism is crucial for improving oxygen evolution reaction (OER) performance, because it could bypass the scaling relation limitation associated with the conventional adsorbate evolution mechanism through the direct formation of oxygen–oxygen bond. High‐valence transition metal sites are favorable for activating the lattice oxygen, but the deep oxidation of pre‐catalysts suffers from a high thermodynamic barrier. Here, taking advantage of the Jahn–Teller (J–T) distortion induced structural instability, we incorporate high‐spin Mn3+ (t2g3eg1 ${{t}_{2g}^{3}{e}_{g}^{1}}$) dopant into Co4N. Mn dopants enable a surface structural transformation from Co4N to CoOOH, and finally to CoO2, as observed by various in situ spectroscopic investigations. Furthermore, the reconstructed surface on Mn‐doped Co4N triggers the lattice oxygen activation, as evidenced experimentally by pH‐dependent OER, tetramethylammonium cation adsorption and online electrochemical mass spectrometry measurements of 18O‐labelled catalysts. In general, this work not only offers the introducing J–T effect approach to regulate the structural transition, but also provides an understanding about the influence of the catalyst's electronic configuration on determining the reaction route, which may inspire the design of more efficient catalysts with activated lattice oxygen. [ABSTRACT FROM AUTHOR]

There are various indoor fingerprint localization techniques utilizing the similarity of received signal strength (RSS) to discriminate the similarity of positions. However, due to the varied states of different wireless access points (APs), each AP's contribution to RSS similarity varies, which affects the accuracy of localization. In our study, we analyzed several critical causes that affect APs' contribution, including APs' health states and APs' positions. Inspired by these insights, for a large-scale indoor space with ubiquitous APs, a threshold was set for all sample RSS to eliminate the abnormal APs dynamically, a correction quantity for each RSS was provided by the distance between the AP and the sample position to emphasize closer APs, and a priority weight was designed by RSS differences (RSSD) to further optimize the capability of fingerprint distances (FDs, the Euclidean distance of RSS) to discriminate physical distance (PDs, the Euclidean distance of positions). Integrating the above policies for the classical WKNN algorithm, a new indoor fingerprint localization technique is redefined, referred to as FDs' discrimination capability improvement WKNN (FDDC-WKNN). Our simulation results showed that the correlation and consistency between FDs and PDs are well improved, with the strong correlation increasing from 0 to 76% and the high consistency increasing from 26% to 99%, which confirms that the proposed policies can greatly enhance the discrimination capabilities of RSS similarity. We also found that abnormal APs can cause significant impact on FDs discrimination capability. Further, by implementing the FDDC-WKNN algorithm in experiments, we obtained the optimal K value in both the simulation scene and real library scene, under which the mean errors have been reduced from 2.2732 m to 1.2290 m and from 4.0489 m to 2.4320 m, respectively. In addition, compared to not using the FDDC-WKNN, the cumulative distribution function (CDF) of the localization errors curve converged faster and the error fluctuation was smaller, which demonstrates the FDDC-WKNN having stronger robustness and more stable localization performance. [ABSTRACT FROM AUTHOR]

The separation of CO activation and C─C coupling enables oxide–zeolite catalyzed tandem reaction toward direct conversion of syngas into light olefins to be a promising alternative for the traditional Fischer–Tropsch process with elevated selectivity. Utilizing controlled mass transfer to match the activation of reactants and the coupling of intermediates presents an appealing strategy to break the limitation on space‐time yield in this tandem process. In this work, ZnCrOx hollow multi‐shelled structures (HoMS) are fabricated to enhance the adsorption and enrichment ability of syngas, thereby strengthening the rate‐determining activation step of reactants and resulting in an accelerated generation of intermediates. When coupled with SAPO zeolite, quintuple‐shelled ZnCrOx HoMS‐based catalysts exhibit a record high C2= ‐C4= space‐time yield of 559 mg·gcat−1·h−1 with a selectivity of 90%. This work demonstrates the advantages of precise nanostructure sculpturing on the mass transfer behavior in the microenvironment and provides a new strategy for highly selective direct conversion of syngas to light olefins, based on efficient activation of reactants and sufficient feeding of intermediates through enrichment effects within HoMS. [ABSTRACT FROM AUTHOR]

Developing cost‐effective and sustainable catalysts with exceptional activity and selectivity is essential for the practical implementation of on‐site H2O2 electrosynthesis, yet it remains a formidable challenge. Metal phosphide core–shell heterostructures anchored in carbon nanosheets (denoted as Ni@Ni2P/C NSs) are designed and synthesized via carbonization and phosphidation of the 2D Ni‐BDC precursor. This core–shell nanostructure provides more accessible active sites and enhanced durability, while the 2D carbon nanosheet substrate prevents heterostructure aggregation and facilitates mass transfer. Theoretical calculations further reveal that the Ni/Ni2P heterostructure‐induced optimization of geometric and electronic structures enables the favored adsorption of OOH* intermediate. All these features endow the Ni@Ni2P/C NSs with remarkable performance in 2e ORR for H2O2 synthesis, achieving a top yield rate of 95.6 mg L−1 h−1 with both selectivity and Faradaic efficiency exceeding 90% under a wide range of applied potentials. Furthermore, when utilized as the anode of an assembled gas diffusion electrode (GDE) device, the Ni@Ni2P/C NSs achieve in situ H2O2 production with excellent long‐term durability (>32 h). Evidently, this work provides a unique insight into the origin of 2e ORR and proposes optimization of H2O2 production through nano‐interface manipulation. [ABSTRACT FROM AUTHOR]

Batteries. A Mn‐doped zeolitic imidazolate framework ZIF‐67 precursor gives rise to triple‐shelled manganese–cobalt oxide hollow dodecahedra. In their Communication on page 996 ff., R. Yu, D. Wang et al. show that these are promising for rechargeable alkaline batteries. [ABSTRACT FROM AUTHOR]

Batterien. Aus dem Mn‐dotierten zeolithischen Imidazolat‐Gerüst ZIF‐67 wurden dreischalige hohle Mangancobaltoxid‐Dodekaeder erhalten. Diese sind vielversprechend für wiederaufladbare Alkalibatterien, wie R. Yu, D. Wang et al. in der Zuschrift auf S. 1008 zeigen. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a disease that has reached epidemic proportions globally in recent years. Consequently, the prevention and treatment of diabetes have become key social challenges. Most of the research on diabetes risk factors has focused on correlation analysis with little investigation into the causality of these risk factors. However, understanding the causality is also essential to preventing the disease. In this study, a causal discovery method for diabetes risk factors was developed based on an improved functional causal likelihood (IFCL) model. Firstly, the issue of excessive redundant and false edges in functional causal likelihood structures was resolved through the construction of an IFCL model using an adjustment threshold value. On this basis, an IFCL-based causal discovery algorithm was designed, and a simulation experiment was performed with the developed algorithm. The experimental results revealed that the causal structure generated using a dataset with a sample size of 2000 provided more information than that produced using a dataset with a sample size of 768. In addition, the causal structures obtained with the developed algorithm had fewer redundant and false edges. The following six causal relationships were identified: insulin→plasma glucose concentration, plasma glucose concentration→body mass index (BMI), triceps skin fold thickness→BMI and age, diastolic blood pressure→BMI, and number of times pregnant→age. Furthermore, the reasonableness of these causal relationships was investigated. The algorithm developed in this study enables the discovery of causal relationships among various diabetes risk factors and can serve as a reference for future causality studies on diabetes risk factors. [ABSTRACT FROM AUTHOR]

This paper introduces a method for high-resolution lattice image reconstruction and dislocation analysis based on diffraction extinction. The approach primarily involves locating extinction spots in the Fourier transform spectrum (reciprocal space) and constructing corresponding diffraction wave functions. By the coherent combination of diffraction and transmission waves, the lattice image of the extinction planes is reconstructed. This lattice image is then used for dislocation localization, enabling the observation and analysis of crystal planes that exhibit electron diffraction extinction effects and atomic jump arrangements during high-resolution transmission electron microscopy (HRTEM) characterization. Furthermore, due to the method's effectiveness in localizing dislocations, it offers a unique advantage when analyzing high-resolution images with relatively poor quality. The feasibility of this method is theoretically demonstrated in this paper. Additionally, the method was successfully applied to observed edge dislocations, such as 1 / 6 [ 21 1 − ] , 1 / 6 [ 2 − 1 1 − ] , and 1 / 2 [ 0 1 − 1 ] , which are not easily observable in conventional HRTEM characterization processes, in electro-deposited Cu thin films. The Burgers vectors were determined. Moreover, this paper also attempted to observe screw dislocations that are challenging to observe in high-resolution transmission electron microscopy. By shifting a pair of diffraction extinction spots and superimposing the reconstructed images before and after the shift, screw dislocations with a Burgers vector of 1 / 2 [ 01 1 − ] were successfully observed in electro-deposited Cu thin films. [ABSTRACT FROM AUTHOR]

The Transformer has emerged as the predominant model in Natural Language Processing due to its exceptional performance in various sequence modeling tasks, particularly in handling long-term dependencies. However, the traditional absolute and relative position encoding methods, which do not learn from data, tend to ignore the inherent structure of natural language sequences due to the position embedding layer at the input end of the Transformer model. This paper introduces a novel learnable neural Ordinary Differential Equation Position Encoding (ODEPE) method that can implicitly capture the natural position relationships within a sequence without requiring additional position embeddings. ODEPE can model continuous sequences and leverage differential equations to simulate the evolution of position information along the sequence, enabling position information to flow seamlessly between sequences. Additionally, a highly effective recurrent attention framework is proposed, which hybridizes attention with the ODEPE method to improve model performance. Compared to the Transformer-based sequence modeling network, our framework demonstrates a performance improvement of 24.0 points on the WikiText-103 dataset, while also achieving a performance improvement of 1.06 points on the Enwik8 dataset. This corresponds to an improvement of 4.9% and 0.17%, respectively. • Novel ODE method for implicit local position encoding in Transformers. • Capture natural sequence position without extra embeddings. • Recurrent attention network captures longer dependencies. • Our method is adaptable, applicable in long-term language modeling. [ABSTRACT FROM AUTHOR]

Forest fire risk prediction is essential for building a forest fire defense system. Ensemble learning methods can avoid the problem of difficult model selection for disaster susceptibility prediction and can significantly improve modeling accuracy. This study introduces a stacking ensemble learning model for predicting forest fire risks in Yunnan Province by integrating various data types, such as meteorological, topographic, vegetation, and human activity factors. A total of 70,274 fire points and an equal number of randomly selected nonfire points were used to develop the model, with 70% of the data allocated for training and the remaining 30% for testing. The stacking model combined four diverse machine learning methods: random forest (RF), extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), and multilayer perceptron (MLP). We evaluated the model's predictive performance using metrics like accuracy, area under the characteristic curve (AUC), and fire density (FD). The results demonstrated that the stacking fusion model exhibited remarkable accuracy with an AUC of 0.970 on the test set, significantly surpassing the performance of individual machine learning models, which had AUC values ranging from 0.935 to 0.953. Furthermore, the stacking fusion model effectively captured the maximum fire density in extremely high susceptibility areas, demonstrating enhanced generalization capabilities. [ABSTRACT FROM AUTHOR]

Background: Changes to human body composition reflect changes in health status to some extent. It has been recognized that these changes occur earlier than diseases. This means that a reasonable prediction of body composition helps to improve model users' health. To overcome the low accuracy and poor adaptability of existing human body composition prediction models and obtain higher efficiency, we proposed a novel method for predicting human body composition which uses a modified adaptive genetic algorithm (MAGA). Methods: Firstly, since there are many parameters for a human body composition model, and these parameters are associated, we designed a new parameter selection approach by combining the improved RReliefF method with the mRMR method. Following this, selected parameters were used to establish a model that fits body composition. Secondly, in order to accurately calculate the weight of parameters in this model, we proposed a solution which used a modified adaptive genetic algorithm, taking advantage of both roulette and optimum reservation strategies. This solution also has an improved selection operator. Thirdly, taking the percentage of body fat (PBF) as an example of body composition, we conducted experiments to compare performance between our algorithm and other algorithms. Results: Through our simulations, we demonstrated that the adaptability of the proposed model is 0.9921, the mean relative error is 0.05%, the mean square error is 1.3 and the correlation coefficient is 0.982. When compared with the indexes of other models, our model has the highest adaptability and the smallest error. Additionally, the suggested model, which has a training time of 28.58s and a running time of 2.84s, is faster than some models. Conclusion: The PBF prediction model established by MAGA has high accuracy, stronger generalization ability and higher efficiency, which could provide a new method for human composition prediction. [ABSTRACT FROM AUTHOR]

To reveal the effects of water vapor on the oxidation mechanism of Al–Zr-based materials, the Al2Zr alloy was oxidized in a wet atmosphere. Water vapor achieves the synchronous oxidation of Al and Zr to form amorphous (Al0.67Zr0.33)O1.66 oxide on the Al2Zr surface. The oxidation kinetics of the Al2Zr alloy is significantly retarded by the presence of water vapor. Compared with the oxygen molecules, water molecules are preferentially adsorbed on the surface, thereby providing fewer oxidizing species for wet oxidation than those for oxygen-involved oxidation. This work provides fundamental insights for surficial protection of structural alloys in humid environments. [ABSTRACT FROM AUTHOR]

Abstract It has been proved that for an immiscible W-Cu system with positive heat of reaction, the immiscibility can be overcome and direct alloying can be realized between the constituent elements at a critical temperature range closes to the melting point of copper (T mCu) in our earlier researches. However, the thermodynamic mechanism of direct alloying between W and Cu is not yet clear. In this paper, a thermodynamic model has been established for direct alloying between W and Cu based on Miedema's theory. Combining the differential scanning calorimetry (DSC) tests for the storage energy in W and Cu, the analysis results based on the model show that the initial energies of W-Cu system including the surface energy, the storage energy and energy caused by external pressure are able to overcome the positive reaction heat and serve as the driving forces for the direct alloying. In other words, the direct alloying between immiscible W and Cu is thermodynamically feasible. Additionally, the thermodynamic analysis results also show that the final alloying microstructure of W-Cu system depends on whether the initial energy is larger than the Gibbs free energy change of W/Cu amorphous phase formation and the cooling rates during the alloying. These thermodynamic calculation results agree well with the experimental results. The amorphous phase is more likely formed during powder metallurgical sintering than during diffusion bonding of W and Cu rods. Lastly, the analysis results explain well why the key to realize direct alloying between W and Cu is to control the alloying temperature at a critical temperature range closes to T mCu. Graphical abstract Image 1 Highlights • Direct alloying between W and Cu is thermodynamically feasible. • E initial including E stor , E surf and E p are the driving forces for direct alloying. • The final alloying microstructure depends on E initial and the cooling rates. • The key to realize alloying to control the alloying temperature closes to T mCu. • The amorphous phase is more likely formed during powder metallurgical sintering. [ABSTRACT FROM AUTHOR]

Development of efficient non-precious and abundant electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is one of the key tasks in renewable energy technologies. Transition-metal selenides have been widely studied as promising candidates. Herein, a layer-structured CoSe2 was used as a precursor, followed by simple one-step dopamine coating. The as-prepared Co0.85Se@NC showed outstanding performance in both ORR and OER catalysis. The onset potential and half-wave potential of the ORR in 0.1 M KOH solution can reach 0.96 V and 0.85 V, respectively. The OER overpotential corresponding to 10 mA cm−2 in 1.0 M KOH solution is only 350 mV, which is much smaller than that of RuO2 (390 mV). Importantly, the catalyst showed good stability, demonstrating that the layered Co0.85Se@NC has great potential for advanced bifunctional electrocatalysis. [ABSTRACT FROM AUTHOR]

Cardiac abnormality detection from Electrocardiogram (ECG) signals is a common task for cardiologists. To facilitate efficient and objective detection, automated ECG classification by using deep learning based methods have been developed in recent years. Despite their impressive performance, these methods perform poorly when presented with cardiac abnormalities that are not well represented, or absent, in the training data. To this end, we propose a novel one-class classification based ECG anomaly detection generative adversarial network (GAN). Specifically, we embedded a Bi-directional Long-Short Term Memory (Bi-LSTM) layer into a GAN architecture and used a mini-batch discrimination training strategy in the discriminator to synthesis ECG signals. Our method generates samples to match the data distribution from normal signals of healthy group so that a generalised anomaly detector can be built reliably. The experimental results demonstrate our method outperforms several state-of-the-art semi-supervised learning based ECG anomaly detection algorithms and robustly detects the unknown anomaly class in the MIT-BIH arrhythmia database. Experiments show that our method achieves the accuracy of 95.5% and AUC of 95.9% which outperforms the most competitive baseline by 0.7% and 1.7% respectively. Our method may prove to be a helpful diagnostic method for helping cardiologists identify arrhythmias. • A novel ECG anomaly detection for the one-class classification analysis task. • We embed temporal information into GAN for better signal synthesis. • The model is more generalisable with the high-dimensional ECG data. [ABSTRACT FROM AUTHOR]

Interdiffusion in epitaxial, single-crystalline Au/Ag bilayered thin films on Si (001) substrates was investigated by Auger electron spectroscopy (AES) sputter-depth profiling and by in-situ positron annihilation Doppler broadening spectroscopy (DBS). By the combination of these techniques identification of the role of vacancy sources and sinks on interdiffusion in the Au/Ag films was possible. It was found that with precise knowledge of the concentration-dependent self-diffusion and impurity diffusion coefficients a distinction between the Darken-Manning treatment and Nernst-Planck treatment can be made, which is not possible on the basis of the determined concentration-depth profiles alone. [ABSTRACT FROM AUTHOR]

Refractory high-entropy alloys (RHEAs) are sensitive to thermal oxidation, significantly restricting their service performance and potential applications. However, the wet oxidation behavior of RHEAs has remained poorly understood despite the potential risk of catastrophic oxidation caused by water vapor. In this study, the oxidation mechanism of an equiatomic TiZrHfNbTaV high-entropy alloy (HEA) has been investigated in a wet atmosphere at elevated temperatures. Synchronous oxidation of all elements occurs at temperatures below 800 °C. At temperatures above 800 °C, preferential oxidation of Nb, Ti, and Zr, and internal oxidation of V occur on HEAs, which are thermodynamically less preferred as compared with oxidations of more reactive Hf and Ta. Experimental and theoretical analyses show that the oxide grain boundaries and substrate interdendritic regions of HEAs act as diffusion pathways for V and oxidizing species during preferential and internal oxidation processes. This work provides a fundamental understanding of the oxidation of multicomponent alloys in wet environments, which is helpful in the development of effective oxidation resistance strategies and innovative surface engineering techniques. • Oxidation of TiZrHfNbTaV high-entropy alloy in a wet atmosphere at 600–900 °C was investigated. • Synchronous oxidation of all elements occurs at temperatures below 800 °C. • Preferential oxidation of Nb, Ti, and Zr occurs on RHEAs, with internal oxidation of V at temperatures above 800 °C. • The oxide grain boundary and substrate interdendritic diffusion play essential roles in wet oxidation behaviors of RHEAs. [ABSTRACT FROM AUTHOR]

The oxidation of amorphous Al 0.44 Zr 0.56 alloys upon exposure to pure O 2 (g) at 500 and 560 °C (and p O2 = 1 × 10 5 Pa) was investigated by a combinatorial experimental approach using X-ray diffraction, spectroscopic ellipsometry, transmission electron microscopy and Auger electron spectroscopy. During the early stages of oxidation at 500 and 560 °C, an amorphous (Zr,Al)-oxide layer of homogeneous composition and uniform thickness is formed, which is enriched in Zr with respect to the alloy substrate. At 500 °C, both the alloy substrate and the oxide layer remain amorphous during continued oxidation, whereas at 560 °C, a crystalline tetragonal ZrO 2 ( t -ZrO 2 ) phase nucleates after prolonged oxidation, while the alloy remains amorphous. The nucleation and growth of t -ZrO 2 at 560 °C occurs exclusively close to the interface between the initially formed amorphous (Zr,Al)-oxide layer and the alloy, immediately underneath a region of Al enrichment in the substrate, as triggered by oxidation-induced compositional changes in the alloy below the reacting alloy/oxide interface and a favorable energy of the interface between t -ZrO 2 crystallites and the amorphous alloy matrix. The growing t -ZrO 2 oxide crystallites eventually laterally coalesce to form a continuous layer constituted of branches of dendrite-shaped t -ZrO 2 phase crystallites surrounded by an Al-rich amorphous Al–Zr alloy matrix. The underlying mechanism of the oxidation process is discussed. [ABSTRACT FROM AUTHOR]

Simultaneous fitting of independently measured sputter-depth profiles of intensities of Auger electrons or photoelectrons from different Auger transitions (AES) or core levels (XPS) is shown to increase the reliability of the thus determined concentrationdepth profiles in diffusion-annealed thin-film systems, as compared with the usually applied single profile fitting. In this context, an extension of the Mixing-Roughness-Information (MRI) depth model is presented, which includes the concentration dependence of the MRI parameters for mixing and information depth, as well as of the backscattering correction factor and the sputter rate. The thus proposed procedure is applicable for diffusion lengths as small as a few nanometre and was applied to determine the concentration-dependent self-diffusion coefficients from measured AES and XPS sputter-depth profiles recorded from diffusion-annealed amorphous-Si/polycrystalline Ge bilayers. [ABSTRACT FROM AUTHOR]

The W–Cu materials hold vast potential for applications in electronic information, nuclear energy, and aerospace sectors. Here, we report a new occurrence of solid-state amorphization on the Cu side near W–Cu interface. A potential function with accuracy close to density functional theory (DFT) is constructed using machine learning, while the atomic mechanism of solid amorphous nucleation and growth is unveiled through a combination of in-situ transmission electron microscopy (TEM) and molecular dynamics (MD) simulations. Our findings indicate that the Cu near W–Cu interface experiences an amorphous phase transition at 400 °C. This amorphous nucleation is linked to the stress coupling between the W–Cu interface and dislocations within Cu. The lattice distortion arising from dislocations, combined with interfacial stress, results in lattice twisting, leading to the formation of dislocation pileup, HCP and disordered structures. The results of the in-situ TEM show that the dislocation stacking and HCP structures exist for a short period of time, and these structures quickly turn into disordered structures, eventually forming an amorphous band with a width of about 8 nm at the W–Cu interface. However, the amorphous structure is unstable. As temperature rises, the amorphous structure undergoes recrystallization into an ordered structure. Furthermore, we investigated the atomic diffusion behavior of W–Cu. Simulation results reveal that the defect in W significantly impacts diffusion. In summary, our study provides theoretical support for the nucleation mechanism of solid-state amorphization, the understanding of interfacial stress-strain, and the application of W–Cu materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Iron-based single-atom catalysts (SACs) are considered to the most promising catalysts to replace Pt for efficient oxygen reduction reaction (ORR). However, the precise synthesis of high-performance SACs and the understanding of their ORR origin remain challenging. In this work, microporous nitrogen-doped carbon with abundant and accessible atomically dispersed N-coordinated Fe sites (Fe-N-C) is prepared by molecular-confined coupling pyrolysis strategy. The Fe-N-C exhibits excellent ORR activities in acid (E 1/2 of 0.78 V vs. RHE) and alkaline (E 1/2 of 0.91 V vs. RHE) electrolytes. When integrated into a rechargeable aqueous Zinc-air battery (ZAB), both large specific capacity (770 mAh g−1) and high peak power density (240 mW cm−2) are achieved. Remarkably, the as-prepared ZAB presents amazing charge-discharge cycle performance of 1600 h at the large current density, which is 52.5 times of that using Pt/C+RuO 2. Furthermore, all-solid-state ZAB delivers ultra-robust cycling stability even under bending. This work may advance a critical step towards the design of rational and controlled preparation of remarkable and ultra-stable catalysts. • Fe-N-C single-atom catalyst is prepared by molecular-confined coupling pyrolysis strategy. • The obtained Fe-N-C has a large SD mass of 2.24 × 1020 sites g−1. • Fe-N-C shows excellent ORR activities in both alkaline (E 1/2 : 0.91 V) and acid (E 1/2 : 0.78 V) electrolytes. • ZAB with Fe-N-C air cathode presents long-term charge/discharge cycle performance of 1600 h. • The solid-state ZAB delivers ultra-robust cycling stability and high energy efficiency. [ABSTRACT FROM AUTHOR]

In current plant phenotyping research, the study of plant time-series images based on deep learning has received widespread attention. While such image data is relatively easy to obtain, the cost of annotation is high. One efficient method for achieving cost-effective training is through contrastive learning. Plant growth is slow, and the changes in image sequences over a period of time are small, with simple semantic information. Previous contrastive pre-training models struggled to effectively distinguish positive samples from the same image with different augmented views and similar negative samples from different images. Therefore, this paper proposes a method called self-supervised contrastive learning method for plant time-series images with a Priori Distance Embedding (PDE). The semantic information in images corresponding to different phenological stages of plants varies. This method transforms this crucial domain knowledge into prior distances for image pairs and conducts contrastive learning pre-training. The learned weights can be transferred to downstream tasks. Building upon this method, experiments were conducted on cherry time-series images to assess the quality of pre-training through a plant phenotyping image semantic segmentation task. To provide a comprehensive example of plant time-series image phenotypic analysis, this paper establishes a cherry growth temporal model, specifically including PDE pre-training, anomaly detection, semantic segmentation, and recording the results from the temporal dimension. The experiments indicate that this self-supervised contrastive learning method can be effectively applied to the pre-training of plant time-series images, demonstrating broad applicability in various computer vision studies related to plant phenotyping. • A pre-training method for plant images with a Priori Distance Embedding (PDE). • Transforms the phenological information into prior distances for image pairs. • An image acquisition device was built to obtain cherry time series images. • The PDE method was tested by plant phenotype image segmentation task. • We provided an exhaustive example of cherry time-series image phenotypic analysis. [ABSTRACT FROM AUTHOR]

• Temperature affects the oxidation behavior of the refractory high-entropy alloy. • Specimens exhibit complex microstructures after oxidation. • TiNb 2 O 7 provides favorable conditions for the inward diffusion of oxygen. • The oxide layers of the TiZrHfNbTaV alloys contain various complex oxides. The elemental effects and oxide layer evolutions of high-entropy alloys during oxidation have remained largely unclear. The high-temperature oxidation of equimolar refractory high-entropy alloy TiZrHfNbTaV in the air at 800–1000 °C for 1 h was investigated in terms of the oxide layer microstructure and formation mechanism. The non-dense oxides formed on the alloy surface at 800–1000 °C mainly contain TiNb 2 O 7 , providing favorable oxygen diffusion conditions. The growth of the oxide layer is influenced by the oxidation temperatures, free energy of oxides, and elemental segregation. The findings offer fundamental insights into the oxidation mechanism of the refractory high-entropy alloys. [ABSTRACT FROM AUTHOR]

The coupling of TiO2 and SrTiO3 through elaborate bandgap engineering can provide synergies for highly efficient photocatalysts. To further improve the separation between photogenerated electrons and holes, a nano‐heterostructured combination of semicrystalline SrTiO3 (S‐SrTiO3) and anatase TiO2 nanoparticles is designed, and an optimized interface is achieved between uniformly grown S‐SrTiO3 and metal organic framework (MOF)‐derived anatase TiO2 through a controlled hydrothermal process. Besides tuning of the bandgap and broadening of the absorption spectral range, S‐SrTiO3 particles alleviate charge carrier recombination benefiting from the coupling of the semicrystalline SrTiO3 around the interface. Additionally, highly dispersed S‐SrTiO3 on TiO2 provides a good spatial distribution of active sites and the abundant carbon remained from MOF may reduce charge transport resistance. Moreover, the rapid transfer within the nano‐heterostructure promotes the separation of the photogenerated charge carriers. With the above predominant architecture, when used as a photocatalyst, the as‐synthesized S‐SrTiO3/TiO2 heterostructure exhibits exceptionally high photocatalytic performance of 13 005 µmol h–1 g–1 for H2 production, exceeding most oxide‐based photocatalysts reported. This study might provide mechanistic insights into a new perspective for the design and preparation of photocatalysts with novel structure and enhanced catalysis activity. [ABSTRACT FROM AUTHOR]

The kinetics of Fe subsurface dissolution and surface segregation upon annealing Fe/Pd(111) in vacuum/oxygen environment are simulated by the modified Darken model incorporation of oxygen absorption. The simulation results indicate that (1) Fe dissolution takes place only in the subsurface layer upon annealing Fe/Pd(111) in vacuum, and (2) Fe surface segregation takes place by consuming Fe atoms from the FePd3 phase formed in the subsurface layer due to Fe dissolution upon annealing Pd/FePd3/Pd(111) in oxygen environment. These results agree very well with the experimental observations published recently. Meanwhile, a new method for determining the local diffusion coefficient based on the experimental STM observation is proposed by modeling the Fe dissolution kinetics at different annealing temperatures. [ABSTRACT FROM AUTHOR]

Zinc air battery (ZAB) has widely recognized advantages such as high theoretical energy density, environmental friendliness, and safety. However, its cathodic reactions involve sluggish four-electron process oxygen reduction and oxygen evolution reactions (ORR and OER). Therefore, developing a cheap, efficient and durable dual functional oxygen electrocatalyst has important scientific significance and practical value for the development of ZAB. Herein, we applied noble metal free medium-entropy alloy (CoFeNi) nanoparticles which were in embedded nitrogen doped carbon framework (N-PCF) as a highly active and ultra-stable bifunctional electrocatalyst. The CoFeNi@N-PCF was prepared by high temperature thermal shock approach from ion-exchanged ZIF percussor to ensure the uniform dispersion of medium-entropy alloy, hierarchical porosity and strong metal-support interaction. Due to the medium-entropy induced synergistic effects, the as-prepared bifunctional electrocatalyst has a large ORR onset potential (E onset) of 0.92 V and half-wave potential (E 1/2) of 0.85 V (vs. RHE) in 0.1 M KOH. And the overpotential of OER in 1.0 M KOH is only 320 mV at 10 mA cm−2. When used in ZAB, the as-assembled rechargeable ZAB with the self-supported air electrode provides an extremely high-power density of 203 mW cm−2, a superior specific capacity of 812 mAh g−1, and amazing cycled steadily for 600 h. The assembled flexible ZAB with CoFeNi@N-PCF exhibits an excellent stability (over 45 h) and the excellent bending ability under different angles. This work can provide some new insights into the design and preparation of advanced bifunctional oxygen electrocatalysts for next-generation metal-air batteries. [Display omitted] • CoFeNi@N-PCF is developed via the thermal shock strategy in milliseconds. • CoFeNi@N-PCF shows encouraging ORR and OER performance. • CoFeNi@N-PCF with the tailored electron structure furnishes extraordinary electrochemical activity. • Rechargeable aqueous and flexible Zn-air batteries with CoFeNi@N-PCF display remarkable performance. [ABSTRACT FROM AUTHOR]

Structural disordering leads to outstanding mechanical properties of amorphous alloys. Many properties are strongly related to formation of surface oxide layers. An in-depth understanding of effect of structural disordering of amorphous alloys on oxide evolution is essential for applications. This paper presents a review of recent comparative oxidation studies of Zr-based amorphous and single-phase crystalline counterpart alloys. Three representative model alloy systems are selected: Zr–Cu and Zr–Al representing alloys with components of different and similar oxygen affinities, respectively, and Zr–Cu–Al representing multi-component alloys. In combination with molecular dynamic simulations, the fundamental role of the structural disordering of parent alloys in the oxidation processes is revealed. The oxidation of Zr–Cu–Al–Ni amorphous alloys at the supercooled liquid temperature region is further reviewed to clarify the relationship between oxidation and substrate crystallization. • A focused review of role of structural disordering of amorphous alloys on thermal oxidation. • Three representative alloys with simple compositions were selected as model alloy systems. • Structural disorder of parent alloys influences strikingly oxide evolution and oxidation kinetics. • The disputes on the oxidation kinetics of amorphous and crystalline states were clarified. [ABSTRACT FROM AUTHOR]

The high-temperature oxidation of ZrAl2 upon exposure to pure O2 at 800–950 °C was studied in terms of the oxidation kinetics and the formation mechanism of the oxide layer. The alloy followed parabolic oxidation kinetics, and the activation energy of oxidation was 239 ± 14 kJ/mol. During the early stages of oxidation below 850 °C, a single-layer oxide formed due to the crystallization of the initially formed amorphous oxide layer. A multilayer oxide structure developed at higher temperatures, due to the slightly higher affinity of oxygen for Zr than for Al and the oxidation-induced compositional changes. [ABSTRACT FROM AUTHOR]

During the annealing of Ni and Ni-Mo films, a {110} texture, usually considered to be both of high surface energy and high strain energy, was found to develop. Quantitative thermodynamic model calculations showed that the anomalous formation of this {110} texture originates fundamentally from the grain yielding anisotropy of Ni. Based on extensive grain yielding anisotropy model calculations, a "texture map" based on {111}, {100}, and {110} textures was constructed to predict the texture transition temperatures for different film thicknesses. A kinetic analysis of the texture evolution in the films is further presented, revealing that the texture evolution is controlled by the self-diffusion of atoms at grain boundaries. These findings pave the way for the achievement of unusual surface orientations through the quantitative texture design of thin films. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Graphene of thickness a few atomic layers has been grown in Ni/a-C bilayers at temperatures as low as 300 °C by Ni-induced crystallization of the amorphous carbon (a-C) in high vacuum. The mechanism of such very low-temperature growth of graphene has been investigated by a combinatorial experimental approach including x-ray diffraction, scanning electron microscopy, Auger electron spectroscopy, x-ray photoelectron spectroscopy and transmission electron microscopy. The growth of this few atomic layer thickness graphene has been found to be mediated by a coupled grain-boundary (GB) diffusion/surface diffusion mechanism. GBs in the top Ni sublayer provide fast diffusion paths for C atoms through the Ni layer, as a result of which graphene layers form above the Ni. The revealed low-temperature growth mechanism of graphene induced by contact with a metal can be applicable in advancing research fields as metal-matrix graphene composites and advanced energy storage devices. Image 1 [ABSTRACT FROM AUTHOR]

Due to energy crisis and environmental pollution, it is urgent to develop efficient and cheap catalysts for hydrogen production from water electrolysis. As a cheaper platinum group metal, Ru, a cheaper platinum group metal, is a highly competitive candidate to Pt because of the similar bond energy of M-H. Herein, TiO 2 @nitrogen-doped carbon composite supported superfine Ru nanoparticles was synthesized by high temperature shock in a Joule furnace using Ti-MOF support (Ru/TiO 2 @NC-J). In the extremely rapid process, MOF was quickly converted into highly conductive nitrogen-doped carbon with tiny TiO 2 dispersed in it, and superfine Ru nanoparticles were generated simultaneously in less than 0.5 s. The obtained Ru/TiO 2 @NC-J displays wonderful HER performance in the wide pH range. In 1.0 M KOH solution, the overpotential was as low as 11 mV at 10 mA cm−2 and a Tafel slope was 39.2 mV dec−1, which far exceeded the activity of Pt/C and conventional calcined samples as well as most of the recently reported catalysts. The as-developed electrocatalysts also showed excellent stability to accommodate large working current for long term test without obvious activity loss in universal pH range. Experimental investigations suggest that the strong metal-support interaction dominantly facilitate the activity of electrocatalytic hydrogen evolution reaction (HER), and stability of Ru/TiO 2 @NC-J. This strategy provides a new and super-fast methodology to prepare low-budget and high-performance HER catalysts for practical applications. [Display omitted] • Highly durable and active Ru/TiO 2 @NC-J catalyst was synthesized by using the novel high temperature shock strategy. • The pH-universal catalyst simultaneously exhibits drastically reduced overpotential and Tafel slope. • Ru/TiO 2 @NC-J achieved high stability in universal pH range. • The excellent catalytic HER performance originate from the strong metal-support interaction. [ABSTRACT FROM AUTHOR]