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How ploughing and frictional melting regulate ice-skating friction

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摩擦:英文版 2023年第11期11卷 2036-2058页

作者： Feng DU PENG Ke Ping HONG School of Transportation Science and Engineering Beihang UniversityBeijing 100191China Beijing Sports University Beijing 100084China

The slipperiness of ice is well known while,for ice skating,its mechanism still needs further investigation,where the complex interactions including the thermal conduction of the skate–meltwater–ice system,the ploughing and the frictional melting of ice to the friction force are still unclear.This study presents a theoretical framework and a simplified analytical solution to unveil the friction mechanism when a curved skate sliding on ice.The theory is validated by experiments and the effects of these various factors,including the sliding velocity,the ice temperature,the supporting weight,and the geometry of the skate blade to the friction are revealed in detail.This study finds that the contribution of friction force from the ploughing deformation through skate indentation and that from the fluid friction through the shear motion of the meltwater layer is comparable with each other,which thus clarifies how the ploughing deformation of the ice substrate together with its frictional melting regulates the friction during skating.

关键词： ice friction skating ploughing frictional melting coefficient of friction

Prediction of Seasonal Tropical Cyclone Activity in the NUIST-CFS1.0 Forecast System

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Advances in Atmospheric Sciences 2023年第7期40卷 1309-1325页

作者： ke peng Jing-Jia LUO Yan LIU key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Institute for Climate and Application Research(ICAR)Nanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences and Key Laboratory of Mesoscale Severe Weather/Ministry of EducationNanjing UniversityNanjing 210023China

Prediction skill for the seasonal tropical cyclone(TC)activity in the Northern Hemisphere is investigated using the coupled climate forecast system(version 1.0)of Nanjing University of Information Science and Technology(NUISTCFS1.0).This assessment is based on the seven-month(May to November)hindcasts consisting of nine ensemble members during 1982–2019.The predictions are compared with the Japanese 55-year Reanalysis and observed tropical storms in the Northern Hemisphere.The results show that the overall distributions of the TC genesis and track densities in model hindcasts agree well with the observations,although the seasonal mean TC frequency and accumulated cyclone energy(ACE)are underestimated in all basins due to the low resolution(T106)of the atmospheric component in the model.NUIST-CFS1.0 closely predicts the interannual variations of TC frequency and ACE in the North Atlantic(NA)and eastern North Pacific(ENP),which have a good relationship with indexes based on the sea surface temperature.In the western North Pacific(WNP),NUIST-CFS1.0 can closely capture ACE,which is significantly correlated with the El Ni?o–Southern Oscillation(ENSO),while it has difficulty forecasting the interannual variation of TC frequency in this area.When the WNP is further divided into eastern and western subregions,the model displays improved TC activity forecasting ability.Additionally,it is found that biases in predicted TC genesis locations lead to inaccurately represented TC–environment relationships,which may affect the capability of the model in reproducing the interannual variations of TC activity.

关键词： seasonal tropical cyclone activity interannual variation global ocean-atmosphere coupled forecast system

Bimetallic catalysts as electrocatalytic cathode materials for the oxygen reduction reaction in microbial fuel cell:A review

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Green Energy & Environment 2023年第4期8卷 1043-1070页

作者： ke Zhao Yuanxiang Shu Fengxiang Li Guosong peng College of Municipal and Environmental Engineering Ministry of Education Key Laboratory of Songliao Aquatic EnvironmentJilin Jianzhu UniversityJilin130118China College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaRemediation and Pollution Control for Urban Ecological EnvironmentalNankai UniversityTianjin300350China

Microbial fuel cell(MFC) is one synchronous power generation device for wastewater treatment that takes into account environmental and energy issues, exhibiting promising potential. Sluggish oxygen reduction reaction(ORR) kinetics on the cathode remains by far the most critical bottleneck hindering the practical application of MFC. An ideal cathode catalyst should possess excellent ORR activity, stability, and costeffectiveness, experiments have demonstrated that bimetallic catalysts are one of the most promising ORR catalysts currently. Based on this, this review mainly analyzes the reaction mechanism(ORR mechanisms, synergistic effects), advantages(combined with characterization technologies), and typical synthesis methods of bimetallic catalysts, focusing on the application effects of early Pt-M(M = Fe, Co, and Ni) alloys to bifunctional catalysts in MFC, pointing out that the main existing challenges remain economic analysis, long-term durability and large-scale application, and looking forward to this. At last, the research trend of bimetallic catalysts suitable for MFC is evaluated, and it is considered that the development and research of metal-organic framework(MOF)-based bimetallic catalysts are still worth focusing on in the future, intending to provide a reference for MFC to achieve energy-efficient wastewater treatment.

关键词： Bimetallic catalysts Oxygen reduction reaction Microbial fuel cell Wastewater treatment Power generation

Localization of Oscillation Source in DC Distribution Network Based on Power Spectral Density

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Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 156-167页

作者： Zida Zhao ke peng Richang Xian Xinhui Zhang Shandong University of Technology ZiboChina

Direct current(DC)bus voltage stability is essential for the stable and reliable operation of a DC system.If an oscillation source can be quickly and accurately localized,the oscillation can be adequately eliminated.We propose a method based on the power spectral density for identifying the voltage oscillation source.Specifically,a DC distribution network model combined with the component connection method is developed,and the network is separated into multiple power modules.Compared with a conventional method,the proposed method does not require determining the model parameters of the entire power grid,which is typically challenging.Furthermore,combined with a novel judgment index,the oscillation source can be identified more intuitively and clearly to enhance the applicability to real power grids.The performance of the proposed method has been evaluated using the MATLAB/Simulink software and PLECS RT Box experimental platform.The simulation and experimental results verify that the proposed method can accurately identify oscillation sources in a DC distribution network.

关键词： Direct current(DC)distribution network oscillation source component connection method power spectral density

Deformation and cracking behaviors of proton-irradiated 308L stainless steel weld metal strained in simulated PWR primary water

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Journal of Materials Science & Technology 2022年第25期120卷 36-52页

作者： Xiaodong Lin Qunjia peng En-Hou Han Wei ke Institute of Materials Shanghai UniversityShanghai 200072China Suzhou Nuclear Power Research Institute Suzhou 215004China key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The proton-irradiated 308L stainless steel weld metal was strained by using constant extension rate tensile testing in simulated PWR primary water, and its deformation microstructures and irradiation assisted stress corrosion cracking(IASCC) behavior were investigated. The results suggest that the irradiation significantly increases the SCC susceptibility of 308L weld metal and causes various deformation microstructures including lathy faulted planes, dislocation channels and deformation twins in austenite and atomic plane rotation in δ-ferrite. The propagation of intergranular IASCC cracks is closely related to the location of the crack tip. For the crack tip in the specimen matrix interior, localized deformation is likely the key factor responsible for the crack growth. For the crack tip close to the specimen surface, however, localized corrosion along the grain boundary rather than the localized deformation appears to dominate the crack propagation. Unlike the intergranular cracks, the IASCC cracks along the δ-ferrite/austenite phase boundary can initiate either by crack initiation at the phase boundary or by crack propagation from the grain boundary. In both cases, the cracked phase boundaries contain a large number of carbides and are severely corroded, but no deformation microstructures are observed, which implies that the localized corrosion may play an important role in the IASCC along the phase boundary. In addition, δ-ferrite can retard the IASCC crack propagation along the grain boundary, which is probably related to the reduction of localized deformation by δ-ferrite.

关键词： Stainless steel weld metal Proton irradiation Deformation microstructures Irradiation assisted stress corrosion cracking Grain and phase boundaries

Intermetallic interphases in lithium metal and lithium ion batteries

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InfoMat 2021年第10期3卷 1083-1109页

作者： ke Sun Zhangquan peng Laboratory of Advanced Spectro-electrochemistry and Li-ion Batteries Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina School of Applied Physics and Materials Wuyi UniversityJiangmenChina Tianmu Lake Institute of Advanced Energy Storage Technologies Co.Ltd. LiyangChina

A robust electrode-electrolyte interface is the cornerstone for every battery system,as demonstrated in the meandering history of the development of Li-ion batteries(LIBs).In the thrust to replace the graphite anode with more energetic ones in LIBs,the effectual strategy for stabilizing the original graphite-electrolyte interface becomes obsolete and a new anode-electrolyte interface needs reconfiguration.Unfortunately,this interface has become the Achilles'heel for those anodes,such as Li-metal anode(LMA)and Si-based anode owing to their excessive reductivity,enormous volume change,and so forth.Encouragingly,in the last decade,impressive progress has been made on taming these extremely unstable interfaces and on the solid-state batteries(SSBs)that are reported to be less susceptible to parasitic reactions.One of the distinguished strategies is the application of artificial Li-alloying intermetallic interphases onto the surface of LMA,via the direct introduction of foreign metals to the Li anode or indirect hetero-cations doping in the electrolyte,to regulate the Li deposition/stripping behavior,which has markedly improved the stability of the LMA-electrolyte interface.In parallel,the intermetallic interphases are also witnessed to profoundly enhance the anode-solid electrolyte contact and the corresponding charge transfer kinetics in various SSBs.This review will provide a panoramic overview of the application of the intermetallic interphases at the anode-electrolyte interfaces in the lithium metal batteries(LMBs),SSBs,and also derivative works in the conventional LIBs,which will focus on different concepts,methodologies,and understandings from the encircled studies.

关键词： anode-electrolyte interface intermetallic interphase Li-alloying interphase lithiophilic interphase lithium metal anode

Recent advances in zwitterionic nanoscale drug delivery systems to overcome biological barriers

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Asian Journal of Pharmaceutical Sciences 2024年第1期19卷 49-68页

作者： Xumei Ouyang Yu Liu ke Zheng Zhiqing Pang Shaojun peng Zhuhai Institute of Translational Medicine Zhuhai Precision Medical CenterZhuhai People’s Hospital(Zhuhai Hospital Affiliated with Jinan University)Zhuhai 519000China key Laboratory of Smart Drug Delivery Ministry of EducationDepartment of PharmaceuticsSchool of PharmacyFudan UniversityShanghai 201203China School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China

Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.

关键词： Zwitterionic polymer Nano drug delivery system Biological barrier Targeting delivery Disease treatment

Insights on high temperature friction mechanism of multilayer ta-C films

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Journal of Materials Science & Technology 2022年第2期97卷 29-37页

作者： Jing Wei peng Guo Hao Li Peiling ke Aiying Wang key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Ningbo Institute of Industrial Technology Ningbo 315201China

In this work,the high temperature friction mechanism of the tetrahedral amorphous carbon(ta-C)film was elucidated.The multilayer ta-C film with alternating hard and soft sub-layers exhibited a low friction coefficient of 0.14 at 400℃ before a sudden failure occurred at 4600 cycles.The wear failure was attributed to the gradual consumption of the ta-C film at the contact region.The design of a hard or soft top layer effectively regulated the high temperature friction properties of the multilayer ta-C.The addition of a hard top layer contributed to a low friction coefficient(0.11)and a minor wear rate(4.0×10^(-7)mm^(3)/(N m)),while a soft top layer deteriorated the lubrication effect.It was proposed that the passivation of dangling bonds at the sliding interface dominated the low-friction mechanism of the ta-C film at high temperature,while the friction induced graphitization and the formation of sp^(2)-rich carbonaceous transfer layer triggered C-C inter-film bonding,resulting in serious adhesion force and lubrication failure.Moreover,the multilayer ta-C film with hard top layer obtained excellent friction performance within 500℃,while the high temperature induced oxidation and volatilization of carbon atoms led to the wear failure at 600℃.

关键词： Tetrahedral amorphous carbon Multilayer structure High temperature friction Wear mechanism

Sulfur-deficient Bi_(2)S_(3-x) synergistically coupling Ti_(3)C_(2)T_(x)-MXene for boosting electrocatalytic N_(2) reduction

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Nano Research 2022年第5期15卷 3991-3999页

作者： Yaojing Luo peng Shen Xingchuan Li Yali Guo ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrocatalytic nitrogen reduction reaction(NRR)is an appealing route for the sustainable NH_(3)synthesis,while developing efficientand durable NRR catalysts remains at the heart of achieving high-efficiency N_(2)-to-NH_(3)electrocatalysis.Herein,we rationally combine vacancy and interface engineering to design sulfur-deficient Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene as an effective NRR catalyst.The developed Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene(Bi2S3-xTi_(3)C_(2)T_(x))naturally contained abundant S-vacancies and exhibited a dramatically boosted NRR activity with an NH_(3)yield of 68.3μg·h^(-1)mg^(-1)(-0.6 V)and a Faradaic efficiency of 22.5%(-0.4 V),far superior to pure Bi_(2)S_(3)and Ti_(3)C_(2)T_(x)and surpassing almost all ever reported Bi-and MXene-based NRR catalysts.Theoretical investigations unveiled that the exceptional NRR activity of Bi_(2)S_(3-x)/Ti_(3)C_(2)T_(x)stemmed from its dual-active-center system involving both S-vacancies and interfacial-Bi sites,which could synergistically promote N_(2)adsorption and*N_(2)H formation to result in an energetic-favorable NRR process.

关键词： electrocatalytic nitrogen reduction bismuth catalyst MXene vacancy engineering interface engineering