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Remarkable Wear Resistance in a Complex Concentrated Alloy with Nanohierarchical Architecture and Composition Undulation

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Research 2024年第1期2023卷 403-416页

作者： Yushan Geng Wenyuan Chen Hui Tan jun Cheng Shengyu zhu jun Yang Weimin Liu State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000PR China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049PR China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264000PR China

Sustained wear damages on the sliding surfaces of alloys are generally the culprit responsible for the failure of various mechanical *** by high-entropy effects,here we deliberately deploy nanohierarchical architecture with composition undulation in a Ni50(AlNbTiV)_(50) complex concentrated alloy,which yields ultralow wear rate within the order of 10^(−7) to 10^(−6) mm^(3)/Nm between room temperature and 800℃.Such remarkable wear resistance heretofore represents one of the highest wear resistance reported for the bulk alloys or composites,and originates from the multi-type adaptive friction interface protection governed by intrinsically nano-coupled grains and *** cooperative heterostructure releases gradient frictional stress in stages upon wear at room temperature through the coexistence of multiple deformation pathways while activating a dense nanocrystalline glaze layer upon wear at 800℃ to minimize adhesive and oxidative *** work uncovers a practical avenue for tailoring wear properties with multicomponent heterostructures over a wide temperature range.

关键词： wear alloys friction

On the Difference Between the Skew-rank of an Oriented Graph and the Rank of Its Underlying Graph

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 129-136页

作者： Jia-min zhu Bo-jun Yuan Yi Wang School of Mathematical Sciences Anhui UniversityHefei230601China School of Science Zhejiang University of Science and TechnologyHangzhou310023China

Let G be a simple graph and G~σ be the oriented graph with G as its underlying graph and orientation σ.The rank of the adjacency matrix of G is called the rank of G and is denoted by r(G).The rank of the skew-adjacency matrix of G~σ is called the skew-rank of G~σ and is denoted by sr(G~σ).Let V(G)be the vertex set and E(G) be the edge set of *** cyclomatic number of G,denoted by c(G),is equal to |E(G)|-|V(G)|+ω(G),where ω(G) is the number of the components of *** is proved for any oriented graph G~σ that-2c(G)≤sr(G~σ)-r(G)≤2c(G).In this paper,we prove that there is no oriented graph G~σwith sr(G~σ)-r(G)=2c(G)-1,and in addition,there are infinitely many oriented graphs G~σ with connected underlying graphs such that c(G)=k and sr(G~σ)-r(G)=2c(G)-l for every integers k,l satisfying 0 ≤l≤4k and l≠1.

关键词： cyclomatic number rank skew-rank

Deposition of thin TiO_(2)films on fluorophlogopite particle surface by CVD in fluidized bed reactor to prepare silver pearlescent pigments

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Particuology 2024年第6期89卷 88-98页

作者： Ming Liu Guoqiang Shao Pengpeng Lv jun Li Qingshan zhu State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Two critical parameters:Glossiness and chromaticity space of pearlescent pigments were evaluated based on crystallinity and grain *** the roughness and the vertical distance evolution along the surface of deposited TiO_(2)film are affected by the *** optimal crystallinity of TiO_(2)was deposited at the temperature of 350℃.The TiCl4 concentration effectively changed the grain ***,the high flow rate of fluidizing gas and optimal gas–solid ratio(<0.11 m^(3)/(kg h))restricted the change of TiCl_(4)concentrations in fluidized bed *** this case,the grain size of the deposited TiO_(2)film was about 55 *** on the grain size,the color of pearlescent pigments was adjusted by controlling the film thickness based on TiO_(2)***,the silver pearlescent pigment with high glossiness was prepared by chemical vapor deposition method in a fluidized bed reactor.

关键词： Fluidized bed chemical vapor deposition TiO_(2)film deposition Pearlescent pigment Free powder restrain Crystal growth

Effects of two silicone resin coatings on performance of FeSiAl magnetic powder cores

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Journal of Iron and Steel Research International 2024年第5期31卷 1279-1288页

作者： Jia-qi Liu Zheng-qu zhu Pu Wang Yi-fan Li Jing Pang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Qingdao Yunlu Advanced Materials Technology Co. Ltd.Qingdao266232ShandongChina

Two silicon resins with excellent thermal stability,JH1123 and JH7102,are used as the insulated agents and binders for the gas-atomized FeSiAl powder,and corresponding magnetic powder cores(MPCs)are *** insulation capability and application prospects of the two silicon resins are evaluated by comparing the magnetic properties of the coated powder and *** scanning electron microscopy,energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy results show that uniform insulation layers are both formed on the powder ***1123 has stronger binding ability,and the JH1123-coated powder exhibits severe agglomeration,with d50(average particle size)approximately twice that of the JH7102-coated *** as-prepared MPCs exhibit outstanding soft magnetic ***,the permeability of FeSiAl@JH1123 is up to 74.0,which is 35.5%higher than that of FeSiAl@JH7102 because JH1123 can further improve the density of the *** for FeSiAl@JH7102,it has better direct current bias and lower core loss of 716.9 mW cm^(−3) at 20 mT and 1000 kHz due to its lower coercivity and greater anti-magnetic saturation ability.A comprehensive comparison shows that FeSiAl@JH1123 is suitable for medium and high frequency applications,while FeSiAl@JH7102 is more suitable for high frequency *** indicates that the use of JH1123 and JH7102 silicon resins for binding and insulated coating not only simplifies the preparation process of MPCs,but also enables the controlled production of MPCs for different applications.

关键词： FeSiAl Insulated coating Magnetic powder core Permeability Core loss

Recent progress of in-situ characterization of LiNi_(1−x−y)Co_(x)Mn_(y)O_(2) cathodes for lithium metal batteries: A mini review

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Nano Research 2024年第3期17卷 1384-1401页

作者： Huanzhu Lv Xiaoqi zhu jun Mei Yuanhua Xia Bin Wang Institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 611731China Chengdu Development Center of Science and Technology China Academy of Engineering PhysicsChengdu 610200China Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics(CAEP)Mianyang 621999China

In the context of the gradual popularity of electric vehicles(EVs),the development of lithium battery systems with high energy density and power density is regarded as the foremost way to improve the range of ***_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathodes have been the focus of researchers due to their high energy density,excellent power performance,and low-temperature ***,the elaboration of the decay mechanism of NCM cathode based on lithium metal batteries(LMBs)is still being restricted to the primary *** the past decades,the development and application of advanced in-situ characterization tools have facilitated researchers'understanding of the internal operation mechanism of batteries during charging and *** this minireview,the latest progress of in-situ observation of the NCM cathode by X-ray diffraction(XRD),fourier transform infrared(FT-IR)spectroscopy,Raman spectroscopy,atomic force microscopy(AFM),transmission electron microscope(TEM),optical microscope,and other characterization tools is *** mechanisms of structural degradation,cathode-electrolyte interfaces(CEIs)composition,and dynamic changes of NCM,electrolyte breakdown,and gas production are ***,based on the existing research progress,the opportunities and challenges for future in-situ characterization technology in the study of the mechanism of LMBs are discussed in ***,the purpose of this minireview is to summarize recent work that focuses on the outstanding application of in-situ characterization techniques in the mechanistic study of LMBs,and pointing the way to the future development of high energy density and power density LMBs systems.

关键词： lithium metal batteries(LMBs) In-situ characterization LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)

Day-ahead P2P Energy Sharing Strategy Among Energy Hubs Considering Flexibility of Energy Storage and Loads

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1105-1118页

作者： Penghua Li Wanxing Sheng Qing Duan jun Liang Cunhao zhu China Electric Power Research Institute Beijing 100192China School of Engineering Cardiff UniversityUK IEEE

Multi-energy systems are one of the key technologies to tackle energy crisis and environmental *** energy hub(EH)is a minimum multi-energy *** of multiple EHs through energy routers(ERs)can realize mutual energy *** paper proposes a peer-to-peer(P2P)energy sharing strategy between EHs including ERs in an interconnected system,which is divided into two *** the lower level,a method of determining the charging/discharging constraints of energy storage devices is *** on the Lyapunov optimization method,virtual queues are used to model the energy storage devices and flexible loads in the *** objective is to minimize the overall operating cost of the interconnected *** the upper level,a non-cooperative game model is introduced to minimize the cost of purchasing power from other EHs for each EH.A best response-based method is adapted to find the Nash *** simulation outcomes demonstrate that application of the proposed strategy can reduce operating costs of an interconnected system and each *** basis of a real-world dataset of interconnected EHs,both analytical and numerical results show the effectiveness of the proposed strategy.

关键词： Energy hub energy router Lyapunov optimization non-cooperative game peer to peer virtual queue

The Effects of the Geometry of a Current Collector with an Equal Open Ratio on Output Power of a Direct Methanol Fuel Cell

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Energy Engineering 2024年第5期121卷 1161-1172页

作者： Yingli zhu Jiachi Xie Mingwei zhu jun Zhang Miaomiao Li Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry&Food Machinery and Equipment School of Mechanical EngineeringTianjin University of Science&TechnologyTianjin300222China Tianjin College University of Science and Technology BeijingTianjin301830China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology College of Mechanical and Electrical EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China

The open ratio of a current collector has a great impact on direct methanol fuel cell(DMFC)*** a number of studies have investigated the influence of the open ratio of DMFC current collectors,far too little attention has been given to how geometry(including the shape and feature size of the flow field)affects a current collector with an equal open *** this paper,perforated and parallel current collectors with an equal open ratio of 50%and different feature sizes are designed,and the corresponding experimental results are shown to explain the geometry effects on the output power of the *** results indicate that the optimal feature sizes are between 2 and 2.5 mm for both perforated and parallel flow field in the current collectors with an equal open ratio of 50%.This means that for passive methanol fuel cells,to achieve the highest output power,the optimal feature size of the flow field in both anode and cathode current collectors is between 2 and 2.5 mm under the operating mode of this *** effects of rib and channel position are also investigated,and the results indicate that the optimum pattern depends on the feature sizes of the flow field.

关键词： Direct methanol fuel cell geometry open ratio current collector position

Sequential enantioselective Ugi-4CR/post-Ugi transformation strategy:a precise construction of structurally diverse azaspiro polycyclic scaffolds

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Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao Wu jun-Xiu Shi Yi-Ming Ou Hua-Jie Jiang Yi-jun Fang Qi-Ming Wang quan Gao Jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic *** diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1 e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis

Energy Harvesting in the Wake of An Inverted C-Shaped Bluff Body

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China Ocean Engineering 2024年第1期38卷 68-80页

作者： WANG jun-lei LI Shen-fang Md.Mahbub ALAM zhu Hong-jun HU Guo-biao School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450000China Center for Turbulence Control Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China Internet of Things Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China

This paper proposes a novel wake-induced vibration(WIV)-based energy harvesting system consisting of two bluff *** inverted C-shaped bluff body is stationary installed at the upstream position to generate an interference wake street,and a cylinder bluff body equipped with a transducer is elastically suspended at the downstream position to harness WIV *** hydrodynamics and energy harvesting(EH)performance of the proposed system are investigated via experimental *** reduced velocity(U*)ranging from 2 to 14(the corresponding Reynolds number ranging from 15100 to 106200)is considered in the present *** is found that the wake generated by the inverted C-shaped bluff body significantly affects the EH *** the opening angle(α)of the C-shaped bluff body increases the vibration amplitude of the downstream cylinder,thereby increasing the harvested *** the spacing(L)between two bluff bodies is two times the cylinder diameter(D),the wake-induced vibration(WIV)mode is observed,while the combined WIV and wake galloping(WG)mode occurs whenαis 150°,and L equals 3D or *** average drag coefficient becomes negative when L is 2D,3D,or *** carefully configuring a C-shaped bluff body,the wake generated by it can bring an augmenting effect on the vibration of the downstream EH *** example,the RMS power output of the proposed EH system reaches a maximum of 0.31 W at U*=8 and L=4D,which is 300%greater than that of its traditional ***,after a number of case stud-ies,it is identified that the proposed EH system can achieve the best performance whenαis 150°and L=2D.

关键词： wake-induced vibration vortex-induced vibration galloping energy harvesting bluff body