116 research outputs found

    The application of a lightweight model FA-YOLOv5 with fused attention mechanism in insulator defect detection

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    Insulators are important components of transmission lines, serving as support for conductors and preventing current backflow. However, insulators exposed to natural environments for a long time are prone to failure and can cause huge economic losses. This article proposes a fast and accurate lightweight Fast and Accurate YOLOv5s (FA-YOLO) model based on YOLOv5s model. Firstly, attention mechanisms are integrated into the network module, improving the model’s ability to extract and fuse target features. Secondly, the backbone part of the network is lightweightened to reduce the number of parameters and computations at the cost of slightly reducing the accuracy of detecting a few objects. Finally, the loss function of the model is improved to accelerate the convergence of the network and improve detection accuracy. At the same time, a visual insulator detection interface is designed using PyQt5. The experimental results show that the algorithm in this paper reduces the number of parameters by 28.6%, the computational effort by 35.7%, and the mAP value by 1.7% compared with the original algorithm, and is able to identify defective insulators quickly and accurately in complex backgrounds

    Bifunctional atomically dispersed ruthenium electrocatalysts for efficient bipolar membrane water electrolysis

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    Atomically dispersed catalysts (ADCs) have recently drawn considerable interest for use in water electrolysis to produce hydrogen, because they allow for maximal utilization of metal species, particularly the expensive and scarce platinum group metals. Herein, we report the electrocatalytic performance of atomically dispersed ruthenium catalysts (Ru ADCs) with ultralow Ru loading (0.2 wt%). The as-obtained Ru ADCs (Ru (0.2)-NC) are active for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), which only require a low overpotential (η) of 47.1 and 72.8 mV to deliver 10 mA cm for HER in 0.5 M HSO and 1.0 M KOH, respectively, and of 300 mV for OER in 1.0 M KOH, showing favorable bifunctionality. Density functional theory (DFT) calculations reveal that the Ru-N bonding plays an important role in lowering the energy barrier of the reactions, boosting the HER and OER activities. Furthermore, the bipolar membrane (BPM) water electrolysis using the bifunctional Ru (0.2)-NC as both HER and OER catalysts can afford 10 mA cm under a low cell voltage of only 0.89 V, and does not show any performance decay upon 100 h continuous operation, showing great potential for energy-saving hydrogen production.L. L. acknowledges the financial support from the National Innovation Agency of Portugal through the Mobilizador Programme (Baterias 2030, Grant No. POCI-01-0247-FEDER-046109). B. L. acknowledges the Natural Science Foundation of LiaoNing Province, China (Grant No. 20180510014) for funding. Z. P. Y. is grateful for the scholarship offered by the China Scholarship Council (Grant No. 201806150015). This work was also in part financially supported by: LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM) funded by national funds through FCT/MCTES (PIDDAC); project 2DMAT4FUEL (POCI-01-0145-FEDER-029600 - COMPETE2020 – FCT/MCTES - PIDDAC, Portugal). In addition, this work was carried out in part through the use of the INL Advanced Electron Microscopy, Imaging and Spectroscopy (AEMIS) Facility

    Cluster Beam Deposition of Ultrafine Cobalt and Ruthenium Clusters for Efficient and Stable Oxygen Evolution Reaction

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    Ultrafine cobalt and ruthenium clusters are deposited on carbon paper substrates by cluster beam deposition using a matrix assembly cluster source and a pulsed microplasma cluster source, respectively. When used to catalyze the oxygen evolution reaction (OER), the cobalt and ruthenium clusters show electrocatalytic performance superior to the state-of-the-art Ru/C and RuO2 nanoparticle catalysts on both a mass and a specific-surface-area basis. Typically, the cobalt clusters can deliver 10 mA cm–2 at a low overpotential of 320 mV and show a small Tafel slope of 50 mV dec–1 and a mass-based turnover frequency of 0.01 s–1 at an overpotential of 300 mV, outperforming many cobalt-based OER catalysts

    Phase I study of the Syk inhibitor sovleplenib in relapsed or refractory mature B-cell tumors

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    Sovleplenib (HMPL-523) is a selective spleen tyrosine kinase (Syk) inhibitor with antitumor activity in preclinical models of B-cell malignancy. We conducted a dose-escalation and dose-expansion phase I study of sovleplenib in patients with relapsed/refractory mature Bcell tumors. Dose escalation followed a 3+3 design; patients received oral sovleplenib (200-800 mg once daily [q.d.] or 200 mg twice daily [b.i.d.], 28-day cycles). During dose expansion, patients were enrolled into four cohorts per lymphoma classification and treated at the recommended phase 2 dose (RP2D). Overall, 134 Chinese patients were enrolled (dose escalation, n=27; dose expansion, n=107). Five patients experienced dose-limiting toxicities: one each of amylase increased (200 mg q.d.), febrile neutropenia (800 mg q.d), renal failure (800 mg q.d.), hyperuricemia and blood creatine phosphokinase increased (200 mg b.i.d.) and blood bilirubin increased and pneumonia (200 mg b.i.d.). RP2D was determined as 600 mg (>65 kg) or 400 mg (≀65 kg) q.d. The primary efficacy end point of independent review committee–assessed objective response rate in indolent B-cell lymphoma was 50.8% (95% CI, 37.5–64.1) in 59 evaluable patients at RP2D (follicular lymphoma: 60.5%, marginal zone lymphoma: 28.6%, lymphoplasmacytic lymphoma/Waldenström macroglobulinemia, 0%). The most common (≄10% patients) grade ≄3 treatment-related adverse events in the doseexpansion phase were decreased neutrophil count (29.9%), pneumonia (12.1%) and decreased white blood cell count (11.2%). Pharmacokinetic exposures increased doseproportionally with ascending dose levels from 200–800 mg, without observed saturation. Sovleplenib showed antitumor activity in relapsed/refractory B-cell lymphoma with acceptable safety. Further studies are warranted

    Conformal and continuous deposition of bifunctional cobalt phosphide layers on p-silicon nanowire arrays for improved solar hydrogen evolution

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    Vertically aligned p-silicon nanowire (SiNW) arrays have been extensively investigated in recent years as promising photocathodes for solar-driven hydrogen evolution. However, the fabrication of SiNW photocathodes with both high photoelectrocatalytic activity and long-term operational stability using a simple and affordable approach is a challenging task. Herein, we report conformal and continuous deposition of a di-cobalt phosphide (Co2P) layer on lithography-patterned highly ordered SiNW arrays via a cost-effective drop-casting method followed by a low-temperature phosphorization treatment. The as-deposited Co2P layer consists of crystalline nanoparticles and has an intimate contact with SiNWs, forming a well-defined SiNW@Co2P core/shell nanostructure. The conformal and continuous Co2P layer functions as a highly efficient catalyst capable of substantially improving the photoelectrocatalytic activity for the hydrogen evolution reaction (HER) and effectively passivates the SiNWs to protect them from photo-oxidation, thus prolonging the lifetime of the electrode. As a consequence, the SiNW@Co2P photocathode with an optimized Co2P layer thickness exhibits a high photocurrent density of -21.9 mA.cm(-2) at 0 V versus reversible hydrogen electrode and excellent operational stability up to 20 h for solar-driven hydrogen evolution, outperforming many nanostructured silicon photocathodes reported in the literature. The combination of passivation and catalytic functions in a single continuous layer represents a promising strategy for designing high-performance semiconductor photoelectrodes for use in solar-driven water splitting, which may simplify fabrication procedures and potentially reduce production costsThis work was funded by ERDF funds through the Portuguese Operational Programme for Competitiveness and Internationalization COMPETE 2020, and national funds through FCT – The Portuguese Foundation for Science and Technology, under the project “PTDC/CTM-ENE/2349/2014” (Grant Agreement No. 016660). The work is also partially funded by the Portugal-China Bilateral Collaborative Programme (FCT/21102/28/12/2016/S). L. F. Liu acknowledges the financial support of the FCT Investigator Grant (IF/01595/2014) and Exploratory Grant (IF/01595/2014/CP1247/CT0001). L. Qiao acknowledges the financial support of the Ministry of Science and Technology of China (Grant Agreement No. 2016YFE0132400).info:eu-repo/semantics/publishedVersio
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