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Recent progress on mechanisms,principles,and strategies for high-activity and high-stability non-PGM fuel cell catalyst design

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Carbon Energy 2024年第5期6卷 25-52页

作者： Yuping Yuan yun Zheng Dan Luo Weibin Qiu Jiantao wang Xin wang Zhongwei Chen GRINM(Guangdong)Institute of New Materials Technology FoshanChina Department of Chemical Engineering Waterloo Institute for NanotechnologyWaterloo Institute for Sustainable EnergyUniversity of WaterlooWaterlooOntarioCanada Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangdongChina National Power Battery Innovation Center GRINM Group Co.Ltd.BeijingChina

The commercialization of a polymer membrane H2-O2 fuel cell and its widespread use call for the development of cost-effective oxygen reduction reaction(ORR)nonplatinum group metal(NPGM)***,to meet the requests for the real-world fuel cell application and replacing platinum catalysts,it still needs to address some challenges for NPGM catalysts regarding the sluggish ORR kinetics in the cathode and their poor durability in acidic *** response to these issues,numerous efforts have been made to study NPGM catalysts both theoretically and experimentally,developed these into the atomically dispersed coordinated metal-nitrogen-carbon(M-N-C)form over the past *** this review,we present a comprehensive summary of recent advancements on NPGM catalysts with high activity and *** design strategies in terms of optimizing active-site density and enhancing catalyst stability against demetalization and carbon corrosion are *** is also emphasized the importance of understanding the mechanisms and principles behind those strategies through a combination of theoretical modeling and experimental ***,further understanding the mechanisms related to the active-site structure and the formation process of the single-atom active site under pyrolysis conditions is critical for active-site *** the active-site distance is the basic principle for improving catalyst activity through increasing the catalyst active-site *** studies for the catalyst deactivation mechanism and modeling stable active-site structures provide both mechanisms and principles to improve the NPGM catalyst ***,currently remained challenges and perspectives in the future on designing high-performance atomically dispersed NPGM catalysts toward fuel cell application are discussed.

关键词： batteries electrocatalysis energy storage and conversion fuel cells

Highly adaptive triboelectric tactile sensor on the foot of autonomous wall-climbing robots for detecting the adhesion state and avoiding the hazard

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Nano Research 2024年第7期17卷 6518-6526页

作者： Zhaoyang wang Jianhua Liu Ziyu wang Chang Liu Qingyu Chen Chaofan Zhang Wenbo Zhang Jicang Si xiu Xiao Peng Xu Minyi Xu Dalian Key Lab of Marine Micro/Nano Energy and Self-powered System Marine Engineering CollegeDalian Maritime UniversityDalian 116026China Information Science and Technology College Dalian Maritime UniversityDalian 116026China Navigation College Dalian Maritime UniversityDalian 116026China Intelligent Biomimetic Design Lab College of EngineeringPeking UniversityBeijing 100871China

Due to the excellent maneuverability and obstacle crossing of legged robots,it is possible for an autonomous legged wallclimbing robots to replace manual inspection of ship exterior ***,when the magnetic adsorption legged wallclimbing robot steps on the convex point or convex line of the wall,or even when the robot missteps,the robot is likely to detach from the ferromagnetic ***,this paper proposes a tactile sensor for the legged magnetic adsorption wall-climbing robot to detect the magnetic adsorption state and improve the safety of the autonomous crawling of the *** tactile sensor mainly comprises a three-dimensional(3D)-printed shell,a tactile slider,and three isometric sensing units,with an optimized *** experiment shows that the triboelectric tactile sensor can monitor the sliding depth of the tactile slider and control the light-emitting device(LED)signal *** addition,in the demonstration experiment of detecting the adsorption state of the robot's foot,the triboelectric tactile sensor has strong adaptability to various ferromagnetic wall ***,this study establishes a robot gait control system to verify the feedback control ability of the triboelectric tactile *** results show that the robot equipped with the triboelectric tactile sensor can recognize the dangerous area on the crawling wall and autonomously avoid the ***,the proposed triboelectric tactile sensor has great potential in realizing the tactile sensing ability of robots and enhancing the safety and intelligent inspection of ultra-large vessels.

关键词： legged wall-climbing robot ship inspection tactile perception triboelectric sensor

Preparation of tungsten-particle-reinforced Zr-based bulk metallic glass composites by two-step spark plasma sintering:microstructure evolution,densification mechanism and mechanical properties

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Rare Metals 2024年第4期43卷 1793-1808页

作者： yun-Fei Ma Pan Gong Mao Zhang Hui-EHu Zhen Peng Xiao Xu Xin wang Mehdi Malekan Xue-Feng Tang Lei Deng Jun-Song Jin Xin-yun wang State Key Laboratory of Materials Processing and Die and Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China Research Institute of Huazhong University of Science and Technology in Shenzhen Shenzhen518057China Department of Chemistry and Materials Naval University of EngineeringWuhan430032China School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013China College of Machine Shanghai Dianji UniversityShanghai201306China School of Metallurgy and Materials Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

A new two-step spark plasma sintering(TSS)process with low-temperature pre-sintering and high-temperature final sintering has been successfully applied to prepare the tungsten-particle(Wp)-reinforced bulk metallic glass composites(Wp/BMGCs).Compared to normal spark plasma sintering(NS),the densification rate and relative density of Wp/BMGCs can be improved by selecting TSS with appropriate sintering pressure in the low temperature pre-sintering ***,the compressive strength and plastic strain of 30%Wp/BMGCs prepared by TSS are both higher than those of the samples prepared by *** TSS process can significantly enhance the compressive strength of 30%Wp/BMGCs by 12%and remarkably increase the plastic strain by 50%,while the trend is completely opposite for 50%Wp/***-in situ experiments and finite element simulations reveal that uneven temperature distribution among particles during low-temperature pre-sintering causes local overheating at contact points between particles,accelerating formation of sintering neck between particles and plastic deformation of *** the volume fraction of Wp is low,TSS can improve the interface bonding between particles by increasing the number of sintering *** makes the fracture mode of Wp/BMGCs being predominantly transgranular ***,as the volume fraction of Wp increases,the adverse effects of Wp plastic deformation are becoming more and more *** aggregated Wp tends to form a solid"cage structure"that hinders the bonding between particles at the interface;correspondingly,the fracture behavior of Wp/BMGCs is mainly dominated by intergranular ***,reducing the sintering pressure during the low-temperature pre-sintering stage of TSS has been shown to effectively decrease plastic deformation in Wp,resulting in a higher degree of densification and better mechanical properties.

关键词： Bulk metallic glass composites Tungsten particle Two-step spark plasma sintering Densification mechanism Mechanical properties

Modified Biot Elastic Coefficients in Poroelastic Solid

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Journal of Earth Science 2024年第4期35卷 1397-1401页

作者： Chun Yang yun wang Alexey Stovas Liheng wang School of Geophysics and Information Technology China University of GeosciencesBeijing100083China Department of Geoscience and Petroleum Norwegian University of Science and TechnologyTrondheim 7031Norway Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

0 INTRODUCTION Sedimentary rocks predominantly consist of porous solids saturated with fluids,the kinematic and dynamic characteristics of which are described through poroelasticity theory(Biot,1956a,b,1941).The wave propagation in fluid-saturated po-rous rocks obtains extensive attention owing to its relevance in diverse fields,such as ocean acoustics,exploration geophysics,and soil dynamics(Yang et al.,2023a;Xie et al.,2022).

关键词： saturated Elastic a,b

Enhancing the Interaction of Carbon Nanotubes by Metal-Organic Decomposition with Improved Mechanical Strength and Ultra-Broadband EMI Shielding Performance

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Nano-Micro Letters 2024年第7期16卷 281-294页

作者： Yu-Ying Shi Si-Yuan Liao Qiao-Feng wang Xin-yun Xu Xiao-yun wang Xin-Yin Gu You-Gen Hu Peng-Li Zhu Rong Sun Yan-Jun Wan Shenzhen Institute of Advanced Electronic Materials Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Southern University of Science and Technology Shenzhen 518055People’s Republic of China National Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050People’s Republic of China

The remarkable properties of carbon nanotubes(CNTs)have led to promising applications in the field of electromagnetic inter-ference(EMI)***,for macroscopic CNT assemblies,such as CNT film,achieving high electrical and mechanical properties remains challenging,which heavily depends on the tube-tube interac-tions of ***,we develop a novel strategy based on metal-organic decomposition(MOD)to fabricate a flexible silver-carbon nanotube(Ag-CNT)*** Ag particles are introduced in situ into the CNT film through annealing of MOD,leading to enhanced tube-tube *** a result,the electrical conductivity of Ag-CNT film is up to 6.82×10^(5) S m^(-1),and the EMI shielding effectiveness of Ag-CNT film with a thickness of~7.8μm exceeds 66 dB in the ultra-broad frequency range(3-40 GHz).The tensile strength and Young’s modulus of Ag-CNT film increase from 30.09±3.14 to 76.06±6.20 MPa(~253%)and from 1.12±0.33 to 8.90±0.97 GPa(~795%),***,the Ag-CNT film exhibits excellent near-field shield-ing performance,which can effectively block wireless *** innovative approach provides an effective route to further apply macroscopic CNT assemblies to future portable and wearable electronic devices.

关键词： EMI shielding Mechanical strength Carbon nanotubes Metal-organic decomposition Flexibility

Laparoscopic vs open surgery for gastric cancer: Assessing time, recovery, complications, and markers

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 40-48页

作者： yun-Yao Lu yun-Xiao Li Meng He Ya-Li wang Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment Chongqing University Cancer HospitalChongqing 400030China

BACKGROUND Gastric cancer(GC)is one of the most common cancers *** and mortality have increased in recent years,making it an urgent issue to ***-paroscopic radical surgery(LRS)is a crucial method for treating patients with GC;However,its influence on tumor markers is still under *** data of 194 patients treated at Chongqing University Cancer Hospital bet-ween January 2018 and January 2019 were retrospectively *** who underwent traditional open surgery and LRS were assigned to the control(n=90)and observation groups(n=104),*** sample t-tests andχ2 tests were used to compare the two groups based on clinical efficacy,changes in tumor marker levels after treatment,clinical data,and the incidence of posto-perative *** investigate the association between tumor marker levels and clinical efficacy in patients with GC,three-year recurrence rates in the two groups were *** Patients in the observation group had a shorter duration of operation,less in-traoperative blood loss,an earlier postoperative eating time,and a shorter hospital stay than those in the control group(P0.05).After treatment,the overall response rate in the control group was significantly lower than that in the observation group(P=0.001).Furthermore,after treatment,the levels of carbohydrate antigen 19-9,cancer antigen 72-4,carcinoembryonic antigen,and cancer antigen 125 decreased *** observation group also exhibited a significantly lower incidence rate of postoperative complications compared to the control group(P0.05).CONCLUSION LRS effectively treats early gastric cancer by reducing intraoperative bleeding,length of hospital stays,and postoperative complications.I

关键词： Laparoscopic radical surgery Gastric cancer Serum tumor markers Prognosis Recurrence Intraoperative bleeding

Ultra‑Efficient and Cost‑Effective Platinum Nanomembrane Electrocatalyst for Sustainable Hydrogen Production

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Nano-Micro Letters 2024年第6期16卷 95-110页

作者： Xiang Gao Shicheng Dai yun Teng Qing wang Zhibo Zhang Ziyin Yang Minhyuk Park Hang wang Zhe Jia yunjiang wang Yong Yang Department of Mechanical Engineering College of EngineeringCity University of Hong KongTat Chee AvenueKowloon TongKowloonHong KongPeople’s Republic of China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijingPeople’s Republic of China School of Engineering Science University of Chinese Academy of SciencesBeijingPeople’s Republic of China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghaiPeople’s Republic of China School of Materials Science and Engineering Jiangsu Key Laboratory for Advanced Metallic MaterialsSoutheast UniversityNanjingPeople’s Republic of China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongTat Chee AvenueKowloon TongKowloonHong KongPeople’s Republic of China

Hydrogen production through hydrogen evolution reaction(HER)offers a promising solution to combat climate change by replacing fossil fuels with clean energy ***,the widespread adoption of efficient electrocatalysts,such as platinum(Pt),has been hindered by their high *** this study,we developed an easy-to-implement method to create ultrathin Pt nanomembranes,which catalyze HER at a cost significantly lower than commercial Pt/C and comparable to non-noble metal *** Pt nanomembranes consist of highly distorted Pt nanocrystals and exhibit a heterogeneous elastic strain field,a characteristic rarely seen in conventional *** unique feature results in significantly higher electrocatalytic efficiency than various forms of Pt electrocatalysts,including Pt/C,Pt foils,and numerous Pt singleatom or single-cluster *** research offers a promising approach to develop highly efficient and cost-effective low-dimensional electrocatalysts for sustainable hydrogen production,potentially addressing the challenges posed by the climate crisis.

关键词： Platinum Hydrogen evolution reaction Lattice distortion Heterogeneous strain

Dynamic Analysis of A Deepwater Drilling Riser with A New Hang-off System

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China Ocean Engineering 2024年第1期38卷 29-41页

作者： LI Yan-wei LIU xiu-quan wang Jin-long CHEN Guo-ming CHANG Yuan-jiang SHENG Lei-xiang Centre for Offshore Engineering and Safety Technology China University of PetroleumQingdao 266580China National Engineering Laboratory of Offshore Geophysical and Exploration Equipment China University of PetroleumQingdao 266580China China CNOOC Research Institute Co. Ltd.Beijing 100028China

The safety of risers in hang-off states is a vital challenge in offshore oil and gas engineering.A new hang-off system installed on top of risers is proposed for improving the security of *** approach leads to a challenging problem:coupling the dynamics of risers with a new hang-off system combined with multiple structures and complex *** accurately analyze the dynamic responses of the coupled system,a coupled dynamic model is established based on the Euler-Bernoulli beam-column theory and penalty function method.A comprehensive analysis method is proposed for coupled dynamic analysis by combining the finite element method and the Newmarkβ*** analysis program is also developed in MATLAB for dynamic *** simulation results show that the dynamic performances of the risers at the top part are significantly improved by the new hang-off system,especially the novel design,which includes the centralizer and articulation *** bending moment and lateral deformation of the risers at the top part decrease,while the hang-off joint experiences a great bending moment at the bottom of the lateral restraint area which requires particular attention in design and *** platform navigation speed range under the safety limits of risers expands with the new hang-off system in use.

关键词： deepwater drilling riser new hang-off system dynamic analysis finite element method penalty function method

Reversibly Cross-Linking Polyimide and Cyclophosphazene Toward Closed-Loop Recyclable Plastics with High Mechanical Strength,Excellent Flame Retardancy,and Chemical Resistance

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CCS Chemistry 2024年第4期6卷 976-987页

作者： Tingting Guan Xiaohan wang Xi Zhao Xingyuan Lu xiu-Li wang Yu-Zhong wang Junqi Sun State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012 The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064

Traditional flame-retardant plastics are technically difficult to chemically *** development of newtypes of flame-retardant plastics that are intrinsically capable of being closed-loop recycled and are sufficiently robust and stable to satisfy their practical application is urgently *** this study,closed-loop recyclable flame-retardant plastics with high mechanical strength and excellent chemical resistance are fabricated by cross-linking amino-terminated polyimide(PI-NH_(2))and aldehyde-terminated cyclophosphazene(CP-CHO)with imine *** resultant flame-retardant plastic,which is denoted as PI-CP,exhibits a tensile strength of∼115.6 MPa,Young’s modulus of∼2.5 GPa,and glass transition temperature of 316°*** the PI-CP plastic,the imine bonds are isolated within hydrophobic microenvironments generated by the rigid and hydrophobic polyimide chains and the benzene ring of *** a result,the PI-CP plastics are highly stable in highly acidic and basic aqueous solutions and other commonly used organic *** PI-CP plastic shows outstanding flame retardancy with a limiting oxygen index value of 48.8%.More importantly,the PI-CP plastic can be depolymerized to generate the original PI-NH_(2)and CPCHO monomers in high yields(∼97%)and *** recovered monomers can be used to refabricate the original plastics,establishing highly efficient polymer-monomer-polymer circulation and a sustainable plastics economy.

关键词： closed-loop recyclable plastics recyclable polymers reversibly cross-linked polymers flame retardancy supramolecular polymers