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Critical role of carbon support in metal nanoaggregate facilitating Fe-N-C catalyst for PEM fuel cell application

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Journal of Energy Chemistry 2024年第10期97卷 669-676,I0014页

作者： Liming guo Xin Wan Qingtao Liu Xiaofang Liu Jiaxiang Shang Ronghai yu Jianglan Shui School of Materials Science and Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 310023ZhejiangChina

Metal nanoaggregates can simultaneously enhance the activity and stability of Fe-N-C catalysts in proton-exchange-membrane fuel cells(PEMFC).Previous studies on the relevant mechanism have focused on the direct interaction between FeN_(4)active sites and metal ***,the role of carbon support that hosts metal nanoaggregates and active sites has been ***,a Fe-N-C catalyst encapsulating inactive gold nanoparticles is prepared as a model catalyst to investigate the electronic tuning of Au nanoparticles(NPs)towards the carbon *** NPs donate electrons to carbon support,making it rich inπelectrons,which reduces the work function and regulates the electronic configuration of the FeN_(4)sites for an enhanced ORR ***,the electron-rich carbon support can mitigate the electron depletion of FeN_(4)sites caused by carbon support oxidation,thereby preserving its high *** yield and accumulation of H_(2)O_(2)are thus alleviated,which delays the oxidation of the catalyst and benefits the *** to the electron-rich carbon support,the composite catalyst achieves a top-level peak power density of 0.74 W/cm^(2) in a 1.5 bar H_(2)-air PEMFC,as well as the improved *** work elucidates the key role of carbon support in the performance enhancement of the FeN-C/metal nanoaggregate composite catalysts for fuel cell application.

关键词： Fuel cells Oxygen reduction reaction Fe-N-C Hetero-structure catalyst Carbon support

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Experimental Study on the Axial Compression Performance of Bamboo Scrimber Columns Embedded with Steel Reinforcing Bars

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Structural Durability & Health Monitoring 2024年第6期18卷 805-833页

作者： Xueyan Lin Mingtao Wu guodong Li Nan guo Lidan Mei College of Civil Engineering and Transportation Northeast Forestry UniversityHarbin150000China Department of Building Engineering College of Civil EngineeringTongji UniversityShanghai200092China College of Transportation and Civil Engineering Fujian Agriculture and Forestry UniversityFuzhou350002China

In this paper,a new type of bamboo scrimber column embedded with steel bars(rebars)was proposed,and the compression performance was improved by pre-embedding rebars during the preparation of the *** effects of the slenderness ratio and the reinforcement ratio on the axial compression performance of reinforced bamboo scrimber columns were studied by axial compression tests on 28 *** results showed that the increase in the slenderness ratio had a significant negative effect on the axial compression performance of the *** the slenderness ratio increased from 19.63 to 51.96,the failure mode changed from strength failure to buckling failure,and the maximum bearing capacity decreased by 43.03%.The axial compression performance of the reinforced bamboo scrimber columns did not significantly improve at a slenderness ratio of 19.63,but the opposite was true at slenderness ratios of 36.95 and *** the reinforcement ratio increased from 0%to 4.52%,the bearing capacity of those with a slenderness ratio of 51.96 increased by up to 16.99%,and the stiffness and ductility were also ***,based on existing specifications,two modification parameters,the overall elastic modulus Ec and the combined strength fcc,were introduced to establish a calculation method for the bearing capacity of the reinforced bamboo scrimber *** calculation results were compared with the test results,and the results showed that the proposed calculation models can more accurately predict the bearing capacity.

关键词： Bamboo scrimber column steel bar axial compression performance theoretical model

Non-Fully Conjugated Photovoltaic Materials with y-Series Acceptor Backbone for High-Performance Organic Solar Cells

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Chinese Journal of Chemistry 2024年第11期42卷 1307-1318页

作者： Hairui Bai Qunping Fan Ruijie Ma Xia guo Wei Ma Maojie zhang State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’anShaanxi710049 China National Engineering Research Center for Colloidal Materials School of Chemistry&Chemical EngineeringShandong UniversityJinanShandong250100 China Department of Electronic and Information Engineering Research Institute for Smart Energy(RISE)The Hong Kong Polytechnic UniversityKowloon999077 Hong KongChina

In the last few years,organic solar cells(OSCs)have made significant progress in photovoltaic performance,mainly due to the innovative development of active layer materials,especially y-series and related derivatives as acceptors which have become the key factor that boosts the power conversion ***,to achieve high-performance OSCs,an emerging molecular design strategy of applying flexible alkyl units as linkers to construct non-fully conjugated acceptors has been developed and addressed great *** review highlights the non-fully conjugated photovoltaic materials with y-series backbone that enable high-performance *** OSCs have been achieved by some representative non-fully conjugated material *** related molecular design strategies are discussed in ***,a brief summary and future prospect are provided in advancing the non-fully conjugated photovoltaic materials with y-series backbone towards the brighter future.

关键词： Organic solar cells All-polymer solar cells Non-fully conjugated photovoltaic materials Power conversion efficiency Polymer acceptors Organicel ectronics

Degradation Behavior of zn-Cu Stents with Different Coatings in Sodium Chloride Solution

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1564-1580页

作者： Xingpeng Liao Jialuo Huang zhilin Liu Jingru guo Dajiang zheng Pengbo Chen Fuyong Cao Center for Marine Materials Corrosion and Protection Fujian Key Laboratory of Surface and Interface Engineering for High Performance MaterialsCollege of MaterialsXiamen UniversityXiamen361005China Light Alloys Research Institute College of Mechanical and Electrical EngineeringCentral South UniversityChangsha410083China First Affiliated Hospital of Xi’an Jiao Tong University Xi’an710061China

The zn0.6Cu wires are fabricated into stents for the potential biodegradable application of nasal wound *** degradation behavior of zn0.6Cu stents in 0.9 wt%NaCl at 36.5℃ is *** shows that the untreated zn0.6Cu stent experiences severe crevice corrosion with acceleration and autocatalytic effects within the micro-cracks and ruptures at 4.67±1.15 d,with the average corrosion rate of 0.28 mm y^(-1).Fortunately,the anodic polarization(AP)+hydrothermal(H)conversion coating,consisting of znCO_(3),zn(OH)_(2) and znO,could inhibit the crevice corrosion significantly by reducing the cathode/anode ratio,extending the rupture time up to 16.50±2.95 d,with the average corrosion rate of 0.14 mm y^(-1).This research indicates that the biodegradable zn-based stent has some potential applications in nasal wound recovery area.

关键词： zn alloys wires Corrosion behavior Biodegradable stents Coating Degradation characterization

A novel encoding mechanism for particle physics

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Nuclear Science and Techniques 2024年第8期35卷 153-166页

作者： zhi‑Guang Tan Sheng‑Jie Wang you‑Neng guo Hua zheng Aldo Bonasera School of Electronic Information and Electrical Engineering Changsha UniversityChangsha 410003China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710119China Key Laboratory of Quark and Lepton Physics(MOE) Central China Normal UniversityWuhan 430079China Cyclotron Institute Texas A&M UniversityCollege StationTX 77843USA Laboratori Nazionali del Sud INFN95123 CataniaItaly

This study proposes a novel particle encoding mechanism that seamlessly incorporates the quantum properties of particles,with a specific emphasis on constituent *** primary objective of this mechanism is to facilitate the digital registration and identification of a wide range of particle *** design ensures easy integration with different event generators and digital simulations commonly used in high-energy ***,this innovative framework can be easily expanded to encode complex multi-quark states comprising up to nine valence quarks and accommodating an angular momentum of up to 99/*** versatility and scalability make it a valuable tool.

关键词： Multi-quark state Encoding mechanism Constituent quark Particle physics

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Potential transformation of organic matter by microbes in cryoconite,Tibetan Plateau

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Science China Earth Sciences 2024年第6期67卷 1978-1989页

作者： Bixi guo yongqin LIU Kevin Xu zHONG Quan SHI Chen HE Qiang zHENG Ruanhong CAI State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for the Pan-Third Pole Environment Lanzhou UniversityLanzhou 730000China Department of Earth Oceanand Atmospheric SciencesUniversity of British ColumbiaVancouverBC V6T 1Z4Canada State Key Laboratory of Heavy Oil Processing Petroleum Molecules Engineering Center(PMEC)China University of PetroleumBeijing 102249China State Key Laboratory for Marine Environmental Science Collage of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Fujian Key Laboratory of Marine Carbon Sequestration Xiamen UniversityXiamen 361005China

Microorganisms play an essential role in the glacier carbon cycle;how they transform organic matter in mountain glacial cryoconite remains to be ***,we applied ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)and deep sequencing of 16S rRNA gene,to investigate the temporal microbial transformation of dissolved organic matter(DOM)of the Tibetan Plateau *** the 60-day incubation,we found that DOM in cryoconite underwent a three-stage transformation,with decreasing bioavailability over *** microbial community did not change much in the first week while degrading DOM molecules that were associated with higher H/C_(wa)and lower O/C_(wa).During days 15-30,DOM composition remained stable while microbial diversity *** day 60,the DOM was microbially converted into a higher state of recalcitrance,with higher values of aromatic index,O/C_(wa),and lower H/C_(wa),which contained molecules containing more *** among various microbial taxa,like Cyanobacteria,Bacteroidota,Gammaproteobacteria,Firmicutes,and Actinobacteriota,drove the DOM transformation in *** study sheds light on the in-situ transformation of DOM composition meditated by microbial populations in cryoconite at a temporal scale,providing new insights into understanding the microbial roles in the glacier organic carbon transformation.

关键词： Cryoconite Dissolved organic matter Biodegradation Microbial community Temporal variation

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Investigation of Power Density Amplification in Stacked Triboelectric Nanogenerators

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Energy & Environmental Materials 2024年第5期7卷 372-379页

作者： Fan Shen Qin zhang Hengyu guo Chen Cao ying Gong Junlei Wang yan Peng zhongjie Li School of Mechatronic Engineering and Automation Shanghai University Department of Applied Physics Chongqing University Institute of Artificial Intelligence School of Future Technology Shanghai University School of Mechanical and Power Engineering Zhengzhou University Shanghai Artificial Intelligence Laboratory

In engineering practice, the output performance of contact separation TENGs(CS-TENGs) increases with the increase of tribo-pair area, which includes increasing the size of single layer CS-TENGs (SCS-TENGs) or the number of units (zigzag TENGs). However, such two strategies show significant differences in output power and power density. In this study, to seek a universal CS-TENG design solution, the output performance of a SCS-TENG and a zigzag TENG (z-TENG) is systematically compared, including voltage,current, transferred charge, instantaneous power density, and charging power density. The relationship between contact area and output voltages is explored, and the output voltage equation is fitted. The experimental results reveal that SCS-TENGs yield better performance than z-TENGs in terms of voltage, power, and power density under the same total contact area.

关键词： contact separation power density triboelectric nanogenerators zigzag

Average Secrecy Capacity of the Reconfigurable Intelligent Surface-Assisted Integrated Satellite Unmanned Aerial Vehicle Relay Networks

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1849-1864页

作者： Ping Li Kefeng guo Feng zhou XuelingWang yuzhen Huang School of Information Technology Yancheng Institute of TechnologyYancheng224051China School of Space Information Space Engineering UniversityBeijing101407China Space E-Star Communication Technology Co. LtdNanjing210007China Academy of Military Sciences of PLA Beijing100097China

Integrated satellite unmanned aerial vehicle relay networks(ISUAVRNs)have become a prominent topic in recent *** paper investigates the average secrecy capacity(ASC)for reconfigurable intelligent surface(RIS)-enabled ***,an eve is considered to intercept the legitimate information from the considered secrecy ***,we get detailed expressions for the ASC of the regarded secrecy system with the aid of the reconfigurable ***,to gain insightful results of the major parameters on the ASC in high signalto-noise ratio regime,the approximate investigations are further gotten,which give an efficient method to value the secrecy *** last,some representative computer results are obtained to prove the theoretical findings.

关键词： Integrated satellite unmanned aerial vehicle relay networks reconfigurable intelligent surface average secrecy capacity(ASC) asymptotic ASC

Copper/Photoredox-Catalyzed Regioselective 1,4-Addition to 1,3-Enynes: A Convenient Access to Perfluoroalkylated Allenes

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Chinese Journal of Chemistry 2024年第17期42卷 2023-2028页

作者： ya Chen Quanyuan Wang Keyi Peng Lilei Cheng ziyi She guo-Jun Deng Key Laboratory for Green Organic Synthesis and Application of Hunan Province Key Laboratory of EnvironmentallyFriendly Chemistry andApplication of Ministryof EducationCollege of ChemistryXiangtan UniversityXiangtanHunan 411105China Department School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan 453007China

A general and broadly applicable copper and photoredox dual-catalyzed multicomponent 1,4-perfluoroalkylcyanation of 1,3-enynes has been *** protocol enjoys success with high regioselectivity,mild reaction conditions,and excellent functional-group tolerance,allowing the facile synthesis of structurally diverse perfluoroalkylated allenes from readily available fluoroalkyl halides,1,3-enynes and TMscN in a one-pot manner.A reasonable mechanism has been proposed according to a series of control experiments.

关键词： Fluorinated allenes 1 3-Enynes Photoredox Fluoroalkylation Multicomponent reactions Difunctionalization Radicals Regioselectivity