FAIR: Frequency-aware Image Restoration for Industrial Visual Anomaly Detection

Image reconstruction-based anomaly detection models are widely explored in industrial visual inspection. However, existing models usually suffer from the trade-off between normal reconstruction fidelity and abnormal reconstruction distinguishability, which damages the performance. In this paper, we find that the above trade-off can be better mitigated by leveraging the distinct frequency biases between normal and abnormal reconstruction errors. To this end, we propose Frequency-aware Image Restoration (FAIR), a novel self-supervised image restoration task that restores images from their high-frequency components. It enables precise reconstruction of normal patterns while mitigating unfavorable generalization to anomalies. Using only a simple vanilla UNet, FAIR achieves state-of-the-art performance with higher efficiency on various defect detection datasets. Code: https://github.com/liutongkun/FAIR.Comment: 12 pages, 10 figure

Self-supervised Implicit Glyph Attention for Text Recognition

The attention mechanism has become the de facto module in scene text recognition (STR) methods, due to its capability of extracting character-level representations. These methods can be summarized into implicit attention based and supervised attention based, depended on how the attention is computed, i.e., implicit attention and supervised attention are learned from sequence-level text annotations and character-level bounding box annotations, respectively. Implicit attention, as it may extract coarse or even incorrect spatial regions as character attention, is prone to suffering from an alignment-drifted issue. Supervised attention can alleviate the above issue, but it is category-specific, which requires extra laborious character-level bounding box annotations and would be memory-intensive when the number of character categories is large. To address the aforementioned issues, we propose a novel attention mechanism for STR, self-supervised implicit glyph attention (SIGA). SIGA delineates the glyph structures of text images by jointly self-supervised text segmentation and implicit attention alignment, which serve as the supervision to improve attention correctness without extra character-level annotations. Experimental results demonstrate that SIGA performs consistently and significantly better than previous attention-based STR methods, in terms of both attention correctness and final recognition performance on publicly available context benchmarks and our contributed contextless benchmarks

Sulfonated Ti3C2Tx to construct proton transfer pathways in polymer electrolyte membrane for enhanced conduction

Here, Ti3C2Tx sheets, a representative of MXenes, with lamellar structure and hydrophilic surface are prepared, and then functionalized with sulfonated polyelectrolyte brushes (Ti3C2Tx-SO3H) through a facile surface-initiated precipitation-polymerization. The Ti3C2Tx-SO3H is then utilized as a new nanofiller to fabricate hybrid proton exchange membrane, where both acidic sulfonated poly (ether ether ketone) (SPEEK) and basic chitosan (CS) are employed as polymer matrixes. The resultant hybrid membranes are systematically characterized and measured including their microstructures, water uptake and proton conduction properties. The results demonstrate that using the sulfonated polyelectrolyte brushes, Ti3C2Tx-SO3H sheets construct efficient proton transfer pathways and connect the inherent conduction channels/paths in polymer phase. This significantly enhances the proton conduction of polymer membrane including SPEEK membrane and CS membrane, under both hydrated condition and anhydrous condition. Particularly, the incorporation of 10 wt.% Ti3C2Tx-SO3H readily offers 144% and 66% increase in proton conductivity, respectively, to SPEEK membrane and CS membrane under hydrated condition. Furthermore, the hybrid membranes achieve improved thermal and mechanical stabilities. These results herald further advances to preparing functionalized MXenes and their relevant hybrid materials with enhanced performances

Local charge rearrangement to boost the chemical adsorption and catalytic conversion of polysulfides for high-performance lithium-sulfur batteries

Owing to their high energy density and low cost, lithium-sulfur (Li-S) batteries are deemed as promising next-generation energy-storage systems. However, the practical applications of Li-S batteries are still intercepted by the notorious shuttle effect and sluggish reaction kinetics. Herein, a porous nitrogen-doped carbon nanorod embedded with ultrafine Bi nanoparticles (Bi-NC) is constructed to function as an advanced sulfur host. The existence of Bi nanoparticles induces the local charge rearrangement and hence optimizes the electronic structure of Bi-NC. As a result, Bi-NC significantly features the effective chemical adsorption and remarkable redox catalyzation for polysulfides, corroborated by both computational and experimental demonstrations. Profiting from these distinctive superiorities, the enhanced utilization of sulfur species and facilitated redox kinetics of polysulfides are achieved. Therefore, the Bi-NC/S electrode delivers a high initial capacity of 1157 mA h g(-1) at 0.5C, a superb capacity retention of 811 mA h g(-1) at 1C after 500 cycles, and an excellent areal capacity of 6.48 mA h cm(-2) even under a high-sulfur loading of 7.0 mg cm(-2). This work affords an innovational regulation of electronic structures via the local charge rearrangement for developing ideal hosts towards the practical high-performance Li-S batteries

Boosting oxygen evolution reactivity by modulating electronic structure and honeycomb-like architecture in Ni2P/N,P-codoped carbon hybrids

Oxygen evolution reaction (OER) as the foremost stumbling block to generate cost-effective clean fuels has received extensive attention in recent years. But, it still maintains the challenge to manipulate the geometric and electronic structure during single reaction process under the same conditions. Herein, we report a simple self-template strategy to generate honeycomb-like Ni2P/N,P-C hybrids with preferred electronic architecture. Experiments coupled with theoretical results revealed that the synthesized catalyst has two characteristics: firstly, the unique honeycomb-like morphology not only enables the fully utilization of catalytic active sites but also optimizes the mass/electron transportation pathway, which favor the diffusion of electrolyte to accessible active sites. Secondly, N,P-C substrate, on the one hand, largely contributes the electronic distribution near Fermi level (E-F) thus boosting its electrical conductivity. On the other hand, the support effect result in the upshift of d-band center and electropositivity of Ni sites, which attenuates the energy barrier for the adsorption of OH- and the formation of *OOH. In consequence, the optimized Ni2P/N,P-C catalysts feature high electrocatalytic activity towards OER (a low overpotential of 252 mV to achieve 10 mA cm(-2)) and 10 h long-term stability, the outstanding performance is comparable to most of transition metal catalysts. This work gives a innovative tactics for contriving original OER electrocatalysts, inspirng deeper understanding of fabricating catalysts by combining theoretical simulation and experiment design. (C) 2020, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd

Engineering Surface Atomic Architecture of NiTe Nanocrystals Toward Efficient Electrochemical N(2)Fixation

Efficient N(2)fixation at ambient condition through electrochemical processes has been regarded as a promising alternative to traditional Haber-Bosch technology. Engineering surface atomic architecture of the catalysts to generate desirable active sites is important to facilitate electrochemical nitrogen reduction reaction (NRR) while suppressing the competitive hydrogen evolution reaction. Herein, nickel telluride nanocrystals with selectively exposed {001} and {010} facets are synthesized by a simple process, realizing the manipulation of surface chemistry at the atomic level. It is found that the catalysts expose the {001} facets coupled with desirable Ni sites, which possess high Faraday efficiency of 17.38 +/- 0.36% and NH(3)yield rate of 33.34 +/- 0.70 mu g h(-1)mg(-1)at -0.1 V vs RHE, outperforming other samples enclosed by {010} facets (8.56 +/- 0.22%, 12.78 +/- 0.43 mu g h(-1)mg(-1)). Both experimental results and computational simulations reveal that {001} facets, with selectively exposed Ni sites, guarantee the adsorption and activation of N(2)and weaken the binding for *H species. Moreover, the enhanced reduction capacity and accelerated charge transfer kinetics also contribute the superior NRR performance of {001} facets. This work presents a novel strategy in designing nonprecious NRR electrocatalyst with exposed favorable active sites

InOOH as an efficient bidirectional catalyst for accelerated polysulfides conversion to enable high-performance lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries with the prominent advantages are greatly expected to be the attractive alternatives in the next-generation energy-storage systems. However, the practical success of Li-S batteries suffers from the shuttle effect and depressed redox kinetics of polysulfides. Herein, for the first time, InOOH nanoparticles are employed as a potent catalytic additive in sulfur electrode to overcome these issues. As demonstrated by the theoretical and experimental results, the strong interactions between the InOOH nanoparticles and sulfur species enable the effective adsorption of polysulfides. More significantly, InOOH nanoparticles not only effectively expedite the reduction of sulfur during the discharge process, but also dramatically accelerate the oxidation of Li2S during the charge process, presenting the marvelous bidirectional catalytic effects. Benefited from these distinctive superiorities, the cells with InOOH nanoparticles harvest an excellent capacity retention of 69.5% over 500 cycles at 2C and a commendable discharge capacity of 891 mAh g1under a high-sulfur loading of 5.0 mg cm2. The detailed investigations in this work provide a novel insight to ameliorate the Li-S electrochemistry by the bidirec-tional catalyst for high-performance Li-S batteries. (c) 2021 Elsevier Inc. All rights reserved

Cu-incorporated PtBi intermetallic nanofiber bundles enhance alcohol oxidation electrocatalysis with high CO tolerance

Atomically ordered intermetallic nanomaterials represent one class of the most attractive catalysts for direct alcohol fuel cells, whereas they remain arduous owing to both the complexity of conventional synthetic approaches and their susceptibility to intermediates (especially CO). Herein, a facile one-step surfactant-free strategy is reported for producing Cu-incorporated PtBi intermetallic nanofiber bundles (Cu-PtBi NFBs) served as robust electrocatalysts towards bifunctional methanol and ethanol oxidation reactions (MOR and EOR). The resultant Cu-PtBi NFBs not only achieve remarkable CO tolerance, and superior mass and specific activities (6.79 A mg(Pt)(-1) and 11.26 mA cm(-2)) with a maximum onset potential shift (77 mV) relative to commercial Pt/C for the MOR, but also show 4.3-fold improved EOR mass activity (4.00 A mg(Pt)(-1)) compared to commercial Pt/C. X-ray absorption fine structure analysis and density functional theory simulation corroborate that the ordered PtBi-based hexagonal close-packed structure, as well as the Cu-induced bifunctional effect, is key to substantially weakening the bonding strength between CO* and Pt sites and strengthening the anchoring of OH* on adjacent Cu sites, thereby optimizing the CO-poisoning pathway. This work provides an effective design strategy for Pt-based intermetallic nano-electrocatalysts as high-efficiency anodic materials in fuel cell applications

CoOx/UiO-66 and NiO/UiO-66 heterostructures with UiO-66 frameworks for enhanced oxygen evolution reactions

The water oxidation reaction involves a four electron-proton coupled process that is kinetically sluggish and has hindered the widespread application of water-splitting technology. Metal-MOF-coupled heterostructures serve as good OER electrocatalysts due to their endowed MOF frameworks and numerous transition metal active sites at the interface. In this study, a simple ultrasonic impregnation strategy was used to prepare CoOx/UiO-66-300 and NiO/UiO-66-300 heterostructures via the impregnation of Co and Ni ions into UiO-66 followed by roasting in air at 300 degrees C to obtain heterostructures with UiO-66-retained frameworks as revealed by SEM. The electrochemical results show that the respective impregnation successfully modulated the electronic charge at the interface of the heterostructures, leading to rapid electron transfer that enhanced the OER activity. CoOx/UiO-66-300 and NiO/UiO-66-300 heterostructures showed good oxygen evolution reaction activities of 283 mV and 291.6 mV, respectively, due to the retained UiO-66 framework, while CoOx/UiO-66-550 and NiO/UiO-66-550 heterostructures calcined at 550 degrees C showed a decrease in OER activities of 332.6 mV and 346.6 mV, respectively, due to the collapsed UiO-66 framework. This work gives insight into the development of heterostructures of MOF-retained frameworks for energy applications

Unveiling Electrochemical Urea Synthesis by Co-Activation of CO2 and N-2 with Mott-Schottky Heterostructure Catalysts

Electrocatalytic C-N bond coupling to convert CO2 and N-2 molecules into urea under ambient conditions is a promising alternative to harsh industrial processes. However, the adsorption and activation of inert gas molecules and then the driving of the C-N coupling reaction is energetically challenging. Herein, novel Mott-Schottky Bi-BiVO4 heterostructures are described that realize a remarkable urea yield rate of 5.91 mmol h(-1) g(-1) and a Faradaic efficiency of 12.55 % at -0.4 V vs. RHE. Comprehensive analysis confirms the emerging space-charge region in the heterostructure interface not only facilitates the targeted adsorption and activation of CO2 and N-2 molecules on the generated local nucleophilic and electrophilic regions, but also effectively suppresses CO poisoning and the formation of endothermic *NNH intermediates. This guarantees the desired exothermic coupling of *N=N* intermediates and generated CO to form the urea precursor, *NCON*