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Atomic-level dispersed nickel sites embedded in carbon support for efficient electrochemical CO2 reduction

International Journal of Hydrogen Energy 2025年 136卷 600-608页

作者： Lu, Jiacheng Gu, Shengshen Xu, Rong Guo, Meng Fang, Juan Zhong, Jing Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology School of Petrochemical Engineering Changzhou University Changzhou213164 China Jiangsu Key Laboratory of Advanced Manufacturing for High-end Chemicals Changzhou University Changzhou213164 China School of Energy and Environmental Engineering University of Science and Technology Beijing Beijing100083 China

Single-atom catalysts have shown exceptional activity and selectivity for CO2 electrochemical reduction reaction (CO2ERR) owing to the clearly defined and accessible active metallic sites. However, the role of Ni dispersion state (atomic vs. aggregated) on catalytic performance has remained elusive. Herein, we report the exploration of dispersion state effects on activities by synthesizing catalysts embedded with Ni single atoms or aggregated particles. The catalyst with highly-dispersed Ni single atoms shows the highest Faradaic efficiency (FECO) for CO (96 % at -0.75 V vs. RHE) and the FECO could be retained for 12 h without a significant decay. While the catalyst with crystalline Ni particles shows a decreased FECO of 80 % and the catalyst with no Ni shows a least FECO of 38 % towards CO. The above experiments indicate that Ni metallic sites are the active centers for CO2ERR and atomic dispersion of Ni metallic sites plays a vital role in CO2ERR performance. Density functional theory (DFT) calculations reveal that the energy barrier of CO2ERR is reduced when Ni is in atomic dispersion rather than aggregation. The findings here have significant implications on a broad field of energy catalysis. © 2025 Hydrogen Energy Publications LLC

关键词： Electrolytic reduction

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Scaled non-passive environmental interaction force tracking for telerobotic manufacturing system with variable time delay

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Science China(Technological Sciences) 2025年第3期68卷 167-178页

作者： Yukui ZHANG Fangyu PENG Yiming WAN Chen CHEN Zhitao GAO Haoyan LIU Yu WANG Rong YAN Xiaowei TANG School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan430074China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan430081China

Robot teleoperation plays an important role in industrial manufacturing in unknown and dangerous environments beyond human *** telerobotic manufacturing tasks,environmental interaction forces may vary significantly from task to ***,it is crucial to provide operators with the specific proportional feedback of environmental interaction forces to enhance their environmental awareness and manipulation ***,variable time delays and various scales of environmental interaction force feedback seriously affect the system stability,which should be rigorously addressed when designing control *** cope with these difficulties,a position and scaled force tracking control framework is proposed and the LyapunovKrasovskii theory is used to obtain a simple algebraic stability criterion with the scaling factor of the environmental interaction force *** addition,a low-pass filter-based radial basis function neural network is designed to avoid the effect of the measurement noise and the sudden change of the non-passive environmental interaction force on the system *** with different controllers in various telerobotic manufacturing tasks such as heavy lifting,cutting,and polishing,our proposed method achieves better position and scaled force tracking performance.

关键词： non-passive interaction force position tracking scaled force tracking stability analysis telerobotic manufacturing system variable time delay

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Iron recovery and dephosphorization behaviors from high-phosphorus oolitic hematite by gas-based direct reduction and magnetic separation

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Journal of Iron and Steel Research International 2025年第3期32卷 550-563页

作者： Fang Liu Yi-chi Zhang Wang Zeng Jun Ni Yun-peng Si Heng Zhou Tian-xiang Zhang Sheng-li Wu Ming-yin Kou State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China

With the depletion of high-quality iron ore resources,high-phosphorus oolitic hematite(HPOH)has attracted great attention due to its large reserve and relatively high iron ***,HPOH is very difficult to be used in ironmaking process due to its special structure.A two-step method of gas-based direct reduction and magnetic separation was thus proposed to recover iron and reduce *** results showed that the powdery reduced iron produced contained 92.31%iron and 0.1%phosphorus,and the iron recovery was 92.65%under optimum reduction condition,which is suitable for following *** apatite will be reduced under long reduction time and a large reducing gas flow rate,resulting in more phosphorus found in the metallic *** the hydrogen–carbon ratio will inhibit the formation and growth of iron particles and prevent the breakage of oolitic *** adjustment of reduction temperature is recommended as it affects the oolitic structure and reduction.

关键词： High-phosphorus oolitic hematite Iron recovery Dephosphorization Gas-based direct reduction Magnetic separation

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Activating lithium storage in 2D CaSi_(2) anode via enhancing pseudocapacitive properties with oxygen modification engineering

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Nano Research 2025年第4期18卷 199-206页

作者： Yongzheng Zhang Lu Sun Kailin Yang Youwang Ye Liang Zhan Qi Wei Jianan Gu Institute of Energy Power Innovation North China Electric Power UniversityBeijing 100096China State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology InstituteBeijing 100024China

Silicon(Si)has emerged as a promising anode material for lithium-ion batteries(LIBs)due to its extremely high theoretical capacity of 4200 mAh·g^(-1).However,its practical application is limited by several critical challenges,including severe volume expansion and poor electrical ***,we employ a two-dimensional(2D)oxygen modification engineering approach to fabricate 2D oxygen-functionalized CaSi_(2)(CaSi_(2)O_(x))*** the preparation of 2D CaSi_(2) layers,O atoms are gradually incorporated onto their *** resulting 2D CaSi_(2)O_(x) layers have a thickness of 3-5 nm,closely matching the theoretical thickness of 6-10 *** used as lithium anodes,the 2D CaSi_(2)O_(x) layers exhibit exceptional electrochemical performance,maintaining stability over 3000 cycles at an ultrahigh current density of 30 A·g^(-1).By tailoring the surface properties,their pseudocapacitive charge storage mechanism is significantly enhanced,effectively overcoming the intrinsic limitations of traditional Si *** study highlights the promise of 2D surface engineering in the development of advanced materials for next-generation LIBs.

关键词： two-dimensional(2D)CaSi_(2)O_(x) Si anode volume change pseudocapacitive surface modification lithium storage

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Generation of 200 fs optical vortex pulses with 12MW peak power from a Yb-doped fiber amplifier

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Optics Letters 2025年第8期50卷 2695-2698页

作者： Luo, Weijia Lin, Di Wang, Shan Yu, Lin Wei, Cunjiang Zhuang, Ziheng Guo, Xiaoyang Liu, Xing Fu, Songnian Qin, Yuwen Institute of Advanced Photonics Technology School of Information Engineering Guangdong University of Technology Guangzhou510006 China Key Laboratory of Photonic Technology for Integrated Sensing and Communication Ministry of Education of China Guangdong University of Technology Guangzhou510006 China Guangdong Provincial Key Laboratory of Information Photonics Technology Guangdong University of Technology Guangzhou510006 China Shenzhen Key Laboratory of Ultra-Intense Laser and Advanced Material Technology Center for Intense Laser Application Technology College of Engineering Physics Shenzhen Technology University Shenzhen518118 China Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes Sino-German College of Intelligent Manufacturing College of Engineering Physics Shenzhen Technology University Shenzhen518118 China

We report the generation of high peak power linearly polarized femtosecond optical vortex pulses based on parabolic pulse amplification within a large-mode-area few-mode Ybdoped fiber (YDF) amplifier system. A dispersion-managed passively mode-locked Yb-doped fiber oscillator with a Gaussian-shaped spectrum serves as the seed source, which evolves into parabolic shape in the subsequent preamplifiers. Aq-plate-based mode converter, positioned before the power amplifier, is employed to convert the Gaussian-shaped beam into optical vortex beams with a topological charge of l=±1. The resulting optical vortex beams are efficiently amplified to an average output power of ∼16.8W at a repetition rate of 3.7 MHz, corresponding to a pulse energy of 4.5 μJ. The chirped output pulses are externally compressed to ∼200 fs, achieving a peak power of ∼12.7MW. To the best of our knowledge, this represents the highest peak power achieved to date for optical vortex pulses generated from a conventional step-index fiber. © 2025 Optica Publishing Group.

关键词： Pulse repetition rate

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Attention-Modulated Feature Fusion Neural Network for Inverse Modeling of Microwave Filters

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IEEE Microwave and Wireless technology Letters 2025年第4期35卷 376-379页

作者： Guo, Linwei Cao, Weihua Hu, Wenkai Lu, Zhengyang Wu, Min China University of Geosciences School of Automation Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education Wuhan430074 China

Inverse modeling is extensively applied in the design and tuning of microwave filters (MFs). Inverse models (IMs) take the features extracted from the high-dimensional electromagnetic parameters as input. How to make full use of features from multiple perspective is a critical issue for improving model accuracy. To solve it, this letter proposes an attention-modulated feature fusion neural network (AMFFNN). AMFFNN achieves multiperspective feature fusion (MPFF) at the input side and independent feature fusion (IFF) at the output side. In addition, feature fusion in AMFFNN is enhanced by attention modules to dynamically identify the importance of each feature. Statistical and comparative results of simulations demonstrate that AMFFNN outperforms existing methods in terms of accuracy, stability, and generalization. © 2023 IEEE.

关键词： Inverse problems

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Corrosion and friction characteristics of microarc oxidation coating on Zr-4 alloy

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Ceramics International 2025年第12期51卷 15232-15241页

作者： Wang, Shuqi Jin, Rui Cui, Yi Ye, Zhiyun Chen, Guoliang Jin, Zhao Zou, Yongchun Xing, Yaru Wang, Yaming Ouyang, Jiahu Jia, Dechang Zhou, Yu Institute for Advanced Ceramics Harbin Institute of Technology Harbin150080 China Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology Harbin Institute of Technology Harbin150001 China State Key Laboratory of Precision Welding & Joining of Materials and Structures China The 18th Institute China Academy of Launch Vehicle Technology Beijing100176 China

To improve the anti-wear and anti-corrosion of core structural materials of nuclear reactors, a relatively dense ceramic coating is fabricated on the Zr-4 alloy surface by microarc oxidation (MAO). Results show that compared with the substrate, the corrosion potential (−0.212V) of MAO coating in the simulated corrosion solution of a nuclear reactor (0.1 mol/L LiOH) exhibits a positive shift, and the corrosion current density (7.50 × 10−11 A∙cm−2) decreases by four orders of magnitude. During the long-term immersion process of the coated samples, the impedance modulus value still remains above 107 Ω cm2, indicating long-term corrosion protection. Moreover, under the GCr15-dry sliding condition, the friction coefficient of MAO coatings is high under various loads and is mainly attributed to abrasive wear. Under the wet lubrication sliding condition, the friction coefficient is low and stable at 0.35, with a good anti-friction effect. To summarize that, the MAO coating can provide sufficient long-term anti-corrosion and anti-wear protection for zirconium-based alloys, showing great potential in nuclear industry fields such as nuclear reactor cladding. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Zirconium alloys

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Degradation state prediction of IGBT based on optimized variational mode decomposition and hybrid models

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Electrical Engineering 2025年 1-21页

作者： He, Deqiang Wang, Yanbo Wu, Jinxin Jin, Zhenzhen Zhao, Ming Chen, Yanjun State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures Guangxi Key Laboratory of Manufacturing System & Advanced Manufacturing Technology School of Mechanical Engineering Guangxi University Nanning530004 China Guangxi Liugong Machinery Co. Ltd Liuzhou545007 China State Key Laboratory of Heavy-Duty and Express High-Power Electric Locomotive Zhuzhou412001 China Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic Technology Guilin541004 China

The insulated gate bipolar transistor (IGBT) is critical in motor drivers. Prolonged operation can lead to gradual degradation, adversely affecting motor operation and system performance. Therefore, accurate IGBT degradation state prediction (DSP) is essential for the timely maintenance and stable operation of motor drivers. The existing methods make it difficult to effectively deal with complex original degradation data, resulting in low DSP accuracy. To solve this issue, an improved method called ISSA-VMD-FDE based on optimized variational mode decomposition (VMD) and hybrid models is presented. Initially, the improved sparrow search algorithm (ISSA) is employed to optimize the VMD with minimum envelope entropy to obtain the key parameter combinations affecting VMD performance. Subsequently, the optimized VMD decomposes the IGBT degradation state data into multiple intrinsic mode functions (IMFs) and calculates each IMF’s fluctuation-based dispersion entropy (FDE). Based on the magnitude of FDE, the IMFs are categorized into high-frequency and low-frequency components. Finally, different models are applied to predict the high-frequency and low-frequency components separately, and the predictions are combined to yield the final DSP results. Experimental results demonstrate that the proposed prediction method exhibits strong predictive performance and reduces the MAPE by 89.41% compared to conventional methods, effectively supporting predictive maintenance and ensuring the reliable operation of IGBT. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Insulated gate bipolar transistors (IGBT)

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Toward High-Accuracy and Low-Latency Group Vehicle Trajectory Prediction With Linear UNet-Enhanced Fully Connected Spatial–Temporal Graph Neural Network

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IEEE Internet of Things Journal 2025年第9期12卷 11797-11811页

作者： Zhang, Zirui Huang, Xumin Yu, Rong Wu, Maoqiang Kang, Jiawen Xie, Shengli Guangdong University of Technology School of Automation Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of Education Guangdong Provincial Key Laboratory of Intelligent Systems and Optimization Integration Guangzhou510006 China South China Normal University School of Electronic Science and Engineering Foshan528225 China Guangdong University of Technology School of Automation 111 Center for Intelligent Batch Manufacturing Based on IoT Technology Guangdong-Hong Kong-Macao Joint Laboratory for Smart Discrete Manufacturing Guangzhou510006 China

Group vehicle trajectory prediction (GVTP) is important for analyzing the traffic states and optimizing the traffic management. However, existing studies have performance bottlenecks in the prediction accuracy and inference latency. To tackle the problems, we propose a linear UNet-enhanced fully connected spatial–temporal GNN (LUFC-STGNN) for GVTP. First, a spatial graph is constructed by integrating prior-based and data-driven methods to capture both explicit and implicit spatial interactions between the vehicles. After that, a comprehensive temporal graph is created to capture the varying strengths of temporal interactions between all vehicles throughout historical timestamps. Furthermore, a fully connected spatial–temporal graph combining the spatial and temporal graphs is introduced to extract the effective spatial–temporal interaction features of the vehicles through the graph convolution operation. Finally, a linear UNet-based temporal dependency encoder (LU-TDE) is designed to further enhance the model’s ability of capturing the potential temporal patterns in the vehicle interactions. The encoder with linear complexity explores the multiscale temporal dependencies from the spatial–temporal interaction features but also reducing the inference latency. Experiments results based on real-world datasets show that compared to state-of-the-art models, our model reduces the average root mean square error over the 5-s prediction horizon by 31% and 10% on the NGSIM and HighD datasets, while reducing the inference latency by at least 1.26 times. © 2014 IEEE.

关键词： Prediction models

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HfC–HfO_(2) modified high/superhigh temperature thermal protection coating for superior hot corrosion resistance and antioxidation performance

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Journal of advanced Ceramics 2025年第1期14卷 177-191页

作者： Zhiyun Ye Shuqi Wang Shuang Yu Xinrui Zhao Yongchun Zou Guoliang Chen Lei Wen Lina Zhao Guangxi Zhang Yaming Wang Jiahu Ouyang Dechang Jia Yu Zhou State Key Laboratory of Precision Welding&Joining of Materials and Structures Harbin Institute of TechnologyHarbin 150001China Institute for Advanced Ceramics Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China Xi’an Aerospace Composites Research Institute Academy of Aerospace Propulsion TechnologyXi’an 710025China

With advances in the thrust-weight ratio,the service temperature of gas turbine engines even exceeds 1500℃,which is urgent for the development of high/superhigh-temperature thermal protection systems(TPSs)for long-term *** alloys are increasingly viewed as promising structural materials for high-temperature applications because of their superior high-temperature mechanical strength,but the“pest”catastrophic oxidation greatly restricts their further *** this study,a HfC–HfO_(2)-modified silicide coating was prepared via an innovative method of halide-activated pack cementation(HAPC)combined with liquid-plasma-assisted particle deposition and sintering of niobium alloys,resulting in a composite coating with excellent hot corrosion resistance and high-temperature oxidation *** modified multilayer coating is characterized by the synergistic combination of a dense NbSi_(2) inner layer and a HfC–HfO_(2) porous outer layer,resulting in a significant improvement in high-temperature performance compared with that of the single NbSi_(2) *** corrosion gain of the composite coating is only 13.94 mg·cm^(−2) after a corrosion time of 200 h at 900℃,and an intact oxide scale surface is observed after oxidation at 1500℃for 500 *** improvement is attributed to the formation of a robust Hf-rich skeleton provided by the deposited HfC–HfO_(2) layer,which can accelerate the formation of a highly stable corroded layer/oxide *** addition,multiple stress release mechanisms of the composite coating at high temperatures also provide substantial contributions to long-term *** these merits make HfC–HfO_(2)-modified composite coatings on niobium alloys competitive for the development of high/superhigh-temperature thermal protection systems for long-term service.

关键词： thermal protection coating niobium alloys hot corrosion resistance high-temperature oxidation resistance stress release mechanism

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