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Targeted Electrocatalysis for High-Performance Lithium–Sulfur Batteries

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Energy & Environmental Materials 2025年第2期8卷 118-128页

作者： Aqsa Nazir Anil Pathak Dambar Hamal Osama Awadallah Saeme Motevalian Ana Claus Vadym Drozd Bilal El-Zahab department of mechanical and Materials engineering College of Engineering and Computing Florida International University

The intricate sulfur redox chemistry involves multiple electron transfers and complicated phase *** have been previously explored to overcome the kinetic barrier in lithium-sulfur batteries（LSBs）.This work contributes to closing the knowledge gap and examines electrocatalysis for enhancing LSB *** a strong chemical affinity for polysulfides,the electrocatalyst enables efficient adsorption and accelerated electron transfer *** cells with catalyzed cathodes exhibit improved rate capability and excellent stability over 500 cycles with 91.9% capacity retention at C/*** addition,cells were shown to perform at high rates up to 2C and at high sulfur loadings up to 6 mg *** electrochemical,spectroscopic,and microscopic analyses provide insights into the mechanism for retaining high activity,coulombic efficiency,and *** work delves into crucial processes identifying pivotal reaction steps during the cycling process at commercially relevant areal capacities and rates.

关键词： batteries catalysts electrochemistry electrodes energy materials

Comparative Evaluation and Performance Analysis of Heat Exchangers Featured with Peened Surface

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Journal of Thermal Science 2025年第1期34卷 50-61页

作者： DINESHBABU Chinnadurai SHIVA SANKARAN Nallasamy VENKATESH RAJAKrishnan VENKATESH Rathinavelu department of mechanical engineering Kongunadu College of Engineering and TechnologyTamil Nadu-621215India department of mechanical engineering Selvam College of TechnologyNamakkalTamil Nadu-637003India department of mechanical engineering Sona College of TechnologySalemTamil Nadu-636005India department of mechanical engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical Sciences(SIMATS)Saveetha UniversityChennai 602105TamilnaduIndia

Heat exchangers have the potential for various engineering applications,and their performance is enriched by surface *** proposed system enriches the heat exchanger's performance by adapting a peened stainless steel(SS)surface blasted with copper,grinding,sand,and *** influences peened SS surface modified with a copper blast,grinding,sandblast,and iron blast on the surface morphology of shell and tube heat exchanger surface(STHE)is analyzed via tungsten heated cathode electron gun featured scanning electron microscope and observed coarse grain *** SS surface featured STHE performance is experimentally evaluated by different flow rates(30,60,90,and 120 L/min)underwater fluid medium functioned by the temperature ranges of 25-75℃ and its results are compared with computational fluid dynamic(CFD)/heat transfer research(HTRI)analyzed *** 60 L/min flow rate was spotted as an optimum value for both shell and tube side *** STHE is operated with a 60 L/min flow rate under the different peened surfaces and evaluated its Stanton number,Nusselt number,logarithmic mean temperature difference(LMTD),overall heat transfer coefficient,number of transfer units(NTU),effectiveness,and exergy *** iron blasted SS peened surface was observed to have better SHTE performance like Stanton number(0.0012),Nusselt number(2180),reduced LMTD of 31℃,improved overall heat transfer co-efficient of 2400 W/(m^(2)·K),better NTU of 0.5532,good effectiveness value of 0.45162,and hiked exergy efficiency of 10% respectively.

关键词： penned surface performance analysis stainless steel shell and tube heat exchanger

Dynamic stress concentration in an infinitely long cylindrical cavity due to a point spherical source embedded within a fluid-saturated poroelastic formation of infinite extent

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 139-156页

作者： H.HOSSEINI O.BALILASHAKI department of mechanical engineering Faculty of EngineeringGolestan UniversityGorgan 15759-49138Iran

The effects of a harmonically exciting monopole source on an infinitely long cylindrical cavity embedded entirely within a fluid-saturated poroelastic formation of infinite extent are examined *** is assumed that the source is located outside the cavity at a specified distance from the borehole *** magnitudes of the hoop and radial stresses beside the pore pressures exerted on the interface and inside the porous medium surrounding the borehole are calculated and ***'s poroelastic modeling along with three types of boundary conditions for the cylindrical interface including the ideal fluid,empty borehole,and rigid inclusion with a hard boundary is employed for the *** a proper translational addition theorem for expressing the incident spherical wave in terms of cylindrical wave expansions,the proposed boundary conditions at the interface are *** are formulated by means of wave potential functions in a three-dimensional(3D)*** effects of the frequency and the radial distance between the source and borehole on the induced stresses are examined for the first cylindrical modes over frequency *** permeability conditions for the interface and three types of soils for the porous formation are considered throughout the *** give an overall outline of the study,a numerical example is *** results clearly indicate that the distance is a key parameter and has considerable effects on the induced stress *** addition,the interface permeability condition and soil characteristics play an important role in determining the dynamic response of the ***,the obtained results are compared with the relevant analyses existing in the literature for some limit cases,and good agreement is achieved.

关键词： point source cylindrical cavity porous medium wave-field transformation stress concentration

Insights into reaction mechanisms:Water's role in enhancing in-situ hydrogen production from methane conversion in sandstone

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Journal of Energy Chemistry 2025年第03期102卷 353-364页

作者： Keju Yan Krishna Prasad Shrestha Mohamed Amine Ifticene Qingwang Yuan Bob L. Herd department of Petroleum engineering Texas Tech University department of mechanical engineering University of Louisiana at Lafayette

In-situ conversion of subsurface hydrocarbons via electromagnetic（EM） heating has emerged as a promising technology for producing carbon-zero and affordable hydrogen（H2） directly from natural gas ***,the reaction pathways and role of water as an additional hydrogen donor in EM-assisted methane-to-hydrogen（CH4-to-H2） conversion are poorly ***,we employ a combination of lab-scale EM-heating experiments and reaction modeling analyses to unravel reaction pathways and elucidate water's role in enhancing hydrogen *** labelled hydrogen isotope of deuterium oxide（D2O） is used to trace the sources of *** results show that water significantly boosts hydrogen yield via coke gasification at around 400℃ and steam methane reforming（SMR） reaction at over 600 ℃ in the presence of ***-gas shift reaction exhibits a minor impact on this *** mechanism analyses reveal that the involvement of water can initiate auto-catalytic loop reactions with methane,which not only generates extra hydrogen but also produces OH radicals that enhance the reactants' *** work provides crucial insights into the reaction mechanisms involved in water-carbon-methane interactions and underscores water's potential as a hydrogen donor for in-situ hydrogen production from natural gas *** also addresses the challenges related to carbon deposition and in-situ catalyst regeneration during EM heating,thus derisking this technology and laying a foundation for future pilots.

关键词： Electromagnetic heating In-situ hydrogen production Methane-to-hydrogen conversion Reaction mechanism Water enhancement

Deep Synchronization Control of Grid-Forming Converters:A Reinforcement Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 273-275页

作者： Zhuorui Wu Meng Zhang Bo Fan Yang Shi Xiaohong Guan the School of Cyber Science and engineering Xi'an Jiaotong University the department of mechanical engineering University of Victoria

Dear Editor,This letter proposes a deep synchronization control(DSC) method to synchronize grid-forming converters with power grids. The method involves constructing a novel controller for grid-forming converters based on the stable deep dynamics model. To enhance the performance of the controller, the dynamics model is optimized within the deep reinforcement learning(DRL) framework. Simulation results verify that the proposed method can reduce frequency deviation and improve active power responses.

关键词： Deep reinforcement learning

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 101-122页

作者： M.GHOLAMI M.EFTEKHARI department of mechanical engineering Shahid Bahonar University of KermanKerman 4545Iran

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGM)that conveys fluids and is equipped with a retaining clip,focusing on primary resonance and subcritical *** nonlinear governing equations for the FGM pipe are derived by the extended Hamilton's principle,and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations.A thorough analysis of various parameters,including the clip stiffness,the power-law index,the porosity,and the clip location,is conducted to gain a comprehensive understanding of the system's nonlinear *** the analysis of the first natural frequency,the study highlights the influence of the flow velocity and the clip stiffness,while the comparisons with metallic pipes emphasize the role of FGM *** examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index,offering valuable insights into the system's nonlinear resonant ***,the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness,revealing nuanced effects on the system response and resonance *** comprehensive analysis enhances the understanding of nonlinear behaviors in FGM porous pipes with a retaining clip,providing key insights for practical engineering applications in system design and optimization.

关键词： functionally graded material(FGM)pipe conveying fuid retaining clip porosity primary resonance subcritical regime

Experimental study on microstructural and corrosion behaviors of friction stir processed steel with CoCrFeCuTi HEA reinforcement and effect of annealing

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Science China(Technological Sciences) 2025年第1期68卷 229-246页

作者： S.Aravind KRISHNA N.RADHIKA Alokesh PRAMANIK N.JEYAPRAKASH department of mechanical engineering Amrita School of EngineeringAmrita Vishwa VidyapeethamCoimbatore 641112India School of Civil and mechanical engineering Curtin UniversityBentley WA 6102Australia School of mechanical and Electrical engineering China University of Mining and TechnologyXuzhou 221116China

The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial *** can be resolved by employing surface modification techniques to modify the surface with the required *** present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA)as reinforcement and the property enhancements *** synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17μm mean particle size and body centred cubic(BCC)*** microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA *** microstructures of the samples annealed at 400℃,550℃,700℃and 850℃for 2 h also showed significant grain growth and grain *** processed sample with HEA reinforcement annealed at 700℃exhibited enhanced microhardness and tensile strength by 63%and 0.88 times than that of the processed sample with HEA *** subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed *** corrosion tests at 900℃showcased excellent resistance for the HEA processed and annealed samples by 14.92%,12.75%,and 14.83%against the samples pre-annealed under three different salt mixtures,and the corroded surface was analyzed.

关键词： high entropy alloys friction stir processing annealing grain refinement corrosion resistance

Target Search and Navigation in Heterogeneous Robot Systems with Deep Reinforcement Learning

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Machine Intelligence Research 2025年第1期22卷 79-90页

作者： Yun Chen Jiaping Xiao department of mechanical engineering University of AlabamaTuscaloosa35487USA School of mechanical and Aerospace engineering Nanyang Technological UniversitySingapore639798Singapore

Collaborative heterogeneous robot systems can greatly enhance the efficiency of target search and navigation *** this paper,we design a heterogeneous robot system consisting of an unmanned aerial vehicle(UAV)and an unmanned ground vehicle(UGV)for search and rescue missions in unknown *** system is able to search for targets and navigate to them in a maze-like mine environment with the policies learned through deep reinforcement learning *** the training process,if two robots are trained simultaneously,the rewards related to their collaboration may not be properly ***,we introduce a multi-stage reinforcement learning framework and a curiosity module to encourage agents to explore unvisited *** in simulation environments show that our framework can train the heterogeneous robot system to achieve the search and navigation with unknown target locations while existing baselines may *** UGV achieves a success rate of 89.1%in the mission within the original environment,and maintains a 67.6%success rate in untrained complex environments.

关键词： Heterogeneous intelligent systems deep reinforcement learning multiagent systems robot learning target search

Few-shot learning for screening 2D Ga_(2)CoS_(4-x) supported single-atom catalysts for hydrogen production

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Journal of Energy Chemistry 2025年第1期100卷 665-673页

作者： Nabil Khossossi Poulumi Dey department of mechanical engineering(ME) Delft University of Technology2628 CD DelftThe Netherlands

Hydrogen generation and related energy applications heavily rely on the hydrogen evolution reaction(HER),which faces challenges of slow kinetics and high *** electrocatalysts,particularly single-atom catalysts (SACs) on two-dimensional (2D) materials,are *** study presents a few-shot machine learning (ML) assisted high-throughput screening of 2D septuple-atomic-layer Ga_(2)CoS_(4-x)supported SACs to predict HER catalytic ***,density functional theory (DFT)calculations showed that 2D Ga_(2)CoS4is inactive for ***,defective Ga_(2)CoS_(4-x)(x=0–0.25)monolayers exhibit excellent HER activity due to surface sulfur vacancies (SVs),with predicted overpotentials (0–60 mV) comparable to or lower than commercial Pt/C,which typically exhibits an overpotential of around 50 m V in the acidic electrolyte,when the concentration of surface SV is lower than 8.3%.SVs generate spin-polarized states near the Fermi level,making them effective HER *** demonstrate ML-accelerated HER overpotential predictions for all transition metal SACs on 2D Ga_(2)CoS_(4-x).Using DFT data from 18 SACs,an ML model with high prediction accuracy and reduced computation time was *** intrinsic descriptor linking SAC atomic properties to HER overpotential was *** study thus provides a framework for screening SACs on 2D materials,enhancing catalyst design.

关键词： Hydrogen production Electrocatalyst 2D material Density functional theory Machine learning Surface sulfur vacancy