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MoS_(2)Lubricate‑Toughened MXene/ANF Composites for Multifunctional Electromagnetic Interference Shielding

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Nano-Micro Letters 2025年第2期17卷 358-371页

作者： Jiaen Wang Wei Ming Longfu Chen Tianliang song Moxi Yele Hao Zhang Long Yang Gegen Sarula Benliang Liang Luting Yan Guangsheng Wang School of Physical Science and Engineering Beijing Jiaotong UniversityBeijing 100044People’s Republic of China Key Laboratory of Bio‑Inspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191People’s Republic of China

The design and fabrication of high toughness electromagnetic interference(EMI)shielding composite films with diminished reflection are an imperative task to solve electromagnetic pollution *** MXene/ANF(aramid nanofibers)–MoS_(2)composite films with nacre-like layered structure here are fabricated after the introduction of MoS_(2)into binary MXene/ANF composite *** introduction of MoS_(2)fulfills an impressive“kill three birds with one stone”improvement effect:lubrication toughening mechanical performance,reduction in secondary reflection pollution of electromagnetic wave,and improvement in the performance of photothermal *** the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 50:50),the strain to failure and tensile strength increase from 22.1±1.7%and 105.7±6.4 MPa and to 25.8±0.7%and 167.3±9.1 MPa,*** toughness elevates from 13.0±4.1 to 26.3±0.8 MJ m^(−3)(~102.3%)*** the reflection shielding effectiveness(SE_(R))of MXene/ANF(mass ratio of 50:50)decreases~10.8%.EMI shielding effectiveness(EMI SE)elevates to 41.0 dB(8.2–12.4 GHz);After the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 60:40),the strain to failure increases from 18.3±1.9%to 28.1±0.7%(~53.5%),the SE_(R)decreases~22.2%,and the corresponding EMI SE is 43.9 *** MoS_(2)also leads to a more efficient photothermal conversion performance(~45 to~55℃).Additionally,MXene/ANF–MoS_(2)composite films exhibit excellent electric heating performance,quick temperature elevation(15 s),excellent cycle stability(2,2.5,and 3 V),and long-term stability(2520 s).Combining with excellent mechanical performance with high MXene content,electric heating performance,and photothermal conversion performance,EMI shielding ternary MXene/ANF–MoS_(2)composite films could be applied in many industrial *** work broadens how to achieve a balance between mechanical properties and versatility of composites in the case of high-function fillers.

关键词： MXene-MoS_(2) Lubrication toughening EMI shielding Photothermal conversion Electric heating performance

Microstructure Characteristic and Electrochemical Corrosion Behavior of Surface Nano-crystallization Modified Carbon Steel

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Journal of Iron and Steel Research International 2016年第12期23卷 1281-1289页

作者： Zhao-jun CHENG Dan song Jin-yang JIANG Jing-hua JIANG Xiao-long MA Kai YOU ai-bin MA College of Mechanics and Materials Hohai UniversityNanjing 210098JiangsuChina School of Materials Science and Engineering Southeast UniversityNanjing 211100JiangsuChina Suqian Research Institute of Hohai University Suqian 223800JiangsuChina Department of Material Science and Engineering North Carolina State UniversityRaleigh 27606US

The surface nano-crystallization （SNC） of carbon steel was achieved via a high-speed rotating wire-brush- ing process. Microstructure characteristics of SNC steel were systematically studied. The SNC steel surface exhibited marked deformed plastic flows and high surface roughness. Due to the accumulated strains, a deformed gradient lay er with thickness of 40-50 μm was produced, and the grain size of the topmost zone was about 50-100 nm. X-ray photoelectron spectroscopy （XPS） analysis indicated that enhanced Fe oxides and Cr oxides were generated. Electrochemical corrosion tests, including open circuit potential （OCP）, electrochemical impendence spectroscopy （EIS）, potentiodynamic polarization （PDP） and potentiostatic polarization （PP） were conducted to study the corrosion be- havior of SNC steel in 3.5 mass% NaC1 solution, where an improved corrosion resistance was observed. The resulted improvement resulted from the dominated positive effects （the attached Cr alloying element and enhanced oxide film） against the negative effects （the higher roughness and the improved corrosion activity of surface microstructure）.

关键词： surface nano-crystallization carbon steel microstructure electrochemical corrosion behavior

Extremal Problems Related to Gauss-John Position

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Acta Mathematica Sinica,English Series 2012年第12期28卷 2527-2534页

作者： ai Jun LI Gang song LENG School of Mathematics and Information Science Henan Polytechnic University Department of Mathematics Shanghai University

In this paper, we consider the extremal problem of the ;p-norm： min{;p（TK）, o E TK C L, T E GL（n）}, where K, L are two convex bodies in Rn. Using the optimization theorem of John, we give necessary conditions for K to be in extremal position in terms of a decomposition of the identity. Fhrthermore, the weaker optimization problem, min{（lp（TK））p ： TK C B2n,TK Sn-1 ≠ O,T E GL（n）}, is also considered. As an application, the geometric distance between the unit ball B2n and a centrally symmetric convex body K is obtained.

关键词： Gauss-John position optimization theorem of John lp-norm contact pair

Preparation of Ni2P/Al-SBA-15 catalyst and its performance for benzofuran hydrodeoxygenation

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Chinese Journal of Chemical Engineering 2017年第12期25卷 1784-1790页

作者： Tianhan Zhu hua song Xueya Dai hualin song Provincial Key Laboratory of Oil & Gas Chemical Technology College of Chemistry & Chemical Engineering Northeast Petroleum University Daqing 163318 China Key Laboratory of Cancer Prevention and Treatment of Heilongjiang Province Mudanjiang Medical University Mudanjiang 157011 China

The Al-doped Ni2P/ai-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of ai on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of ai into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The ai also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of ai can enhance the acid strength. The total deoxygenated product yield over Ni2P/ai-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.

关键词： Ni2P SBA-15 Hydrodeoxygenation Benzofuran ai

Visualization of flow behavior in ore-segregated packed beds with fine interlayers

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International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 900-909页

作者： Lei-ming Wang Sheng-hua Yin ai-xiang Wu Key Laboratory of Ministry of Education for High-Efficient Mining and Safety of Metal University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Department of Materials Engineering University of British Columbia309-6350 Stores RoadVancouver V6T 1Z4BCCanada

Ore particles,especially fine interlayers,commonly segregate in heap stacking,leading to undesirable flow paths and changeable flow velocity fields of packed *** tomography(CT),COMSOL Multiphysics,and MATLAB were utilized to quantify pore structures and visualize flow behavior inside packed beds with segregated fine *** formation of fine interlayers was accompanied with the segregation of particles in packed *** particles reached the upper position of the packed beds during *** revealed that the average porosity of fine interlayers(24.21%)was significantly lower than that of the heap packed by coarse ores(37.42%),which directly affected the formation of flow ***,the potential flow paths in the internal regions of fine interlayers were *** flowed and bypassed the fine interlayers and along the sides of the packed *** velocity also indicated that the flow paths easily gathered in the pore throat where flow velocity(1.8×10^-5 m/s)suddenly *** stagnant regions with a flow velocity lower than 0.2×10^-5 m/s appeared in flow paths with a large diameter.

关键词： fine interlayer flow behavior computed tomography segregation preferential flow

Partial Surface Damper to Suppress Vibration for Thin Walled Plate Milling

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 632-643页

作者： Jiahao SHI Qinghua song Zhanqiang LIU Xing ai key laboratory of high efficiency and clean mechanical manufacture of ministry of education shandong universityJinan 250061China school of mechanical engineering shandong universityJinan 250061China

The material removal rate and required work- piece surface quality of thin-walled structure milling are greatly limited due to its severe vibration, which is directly associated with the dynamic characteristics of the system. Therefore, the suppression of vibration is an unavoidable problem during milling. A novel partial surface damping method is proposed to modify the mode of the thin walled cantilever plate and to suppress vibration during milling. Based on classical plate theory, the design criterion is analyzed and configuration of the partial surface damper is introduced, in which viscoelastic plate and constraining plate are attached to the surface of the plate to increase the system＇s natural frequency and loss factor. In order to obtain the energy expression of the cutting system, the Ritz method is used to describe the unknown displacements. Then, with Lagrange＇s equation, the natural frequency and loss factor are calculated. In addition, the plate is divided into a finite number of square elements, and the regulation of treated position is studied based on theoretic and experimental analysis. The milling tests are conducted to verify its damping performance and the experimentalresults show that with treatment of partial surface damper, the deformation of the hare plate is reduced from 0.27 mm to 0.1 mm, while the vibration amplitude of the bare plate is reduced from 0.08 mm to 0.01 mm. The proposed research provides the instruction to design partial surface damper.

关键词： Partial surface damper Milling process Thin-walled plate

A novel stability prediction approach for thin-walled component milling considering material removing process

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Chinese Journal of Aeronautics 2017年第5期30卷 1789-1798页

作者： Jiahao SHI Qinghua song Zhanqiang LIU Xing ai Key Laboratory of High Efficiency and Clean Mechanical Manufacture Ministry of Education Shandong University Ji'nan 250061 China School of Mechanical Engineering Shandong University Ji'nan 250061 China

The milling stability of thin-walled components is an important issue in the aviation manufacturing industry, which greatly limits the removal rate of a workpiece. However, for a thin-walled workpiece, the dynamic characteristics vary at different positions. In addition, the removed part also has influence on determining the modal parameters of the workpiece. Thus,the milling stability is also time-variant. In this work, in order to investigate the time variation of a workpiece＇s dynamic characteristics, a new computational model is firstly derived by dividing the workpiece into a removed part and a remaining part with the Ritz method. Then, an updated frequency response function is obtained by Lagrange＇s equation and the corresponding modal parameters are extracted. Finally, multi-mode stability lobes are plotted by the different quadrature method and its accuracy is verified by experiments. The proposed method improves the computational efficiency to predict the time-varying characteristics of a thin-walled workpiece.

关键词： Material removal effect Multi-mode Stability Thin-walled workpiece Vibration

Scaling procedures of cabin noise generated by turbulent boundary layer excitation

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Chinese Journal of Aeronautics 2018年第3期31卷 481-489页

作者： Xiaojian ZHAO Wei song Jie ZHOU Bangcheng ai China Academy of Aerospace Aerodynamics Beijing 100074 China University of Southampton Southampton England SO17IBJ United Kingdom

This paper presents a new method for measuring the cabin noise of a structure in a wind tunnel. A method for scaling the cabin sound was derived to obtain the cabin noise of a structure,and the derivation of the scaling procedure was based on a theoretical hypothesis regarding the cabin noise prediction for a scaled model in a wind tunnel. A frequency offset was generated because of the error introduced by model manufacture and installation, and a proposed modal test method was used to eliminate the frequency offset. Both a full-scale structure and scaled structure were measured in the wind tunnel tests. The cabin noise of the full-scale model was compared with the results obtained using the scaling procedure based on the scaled model. The comparisons of the measurement results indicate that the scaling procedures developed in this paper are effective for vibro-acoustic predictions in wind tunnels. Moreover, background noise tended to affect the results of the cabin sound for the wind tunnel test, and thus background noise should be prevented through specific design efforts.

关键词： Cabin noise Scaling procedure Turbulent boundary layer Vibro-acoustic Wind tunnel

Improvement of pitting corrosion resistance for Al-Cu alloy in sodium chloride solution through equal-channel angular pressing

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Progress in Natural Science:Materials International 2011年第4期21卷 307-313页

作者： Dan song,ai-bin MA,Jing-hua JIANG,Ping-hua LIN,Liu-yan ZHANG College of Mechanics and Materials,Hohai University,Nanjing 210098,China College of Mechanics and Materials Hohai University Nanjing 210098 China

Significant corrosion resistance improvement was achieved in solid-solution treated(T4) Al-Cu alloy after severe grain refinement through equal-channel angular *** bulk ultrafine-grained Al-Cu alloy with grain sizes of 200-300 nm has higher pitting potential(elevated by about 34 mV,SCE) and lower corrosion current density(decreased by about 3.88μA/cm~2) in polarization tests than the as-T4 alloy,and increased polarization resistance(increased by about 5.7 kΩ·cm~2) in electrochemical impendence spectrum tests,along with alleviated corrosion damage in immersion *** factors responds to the improved corrosion resistance of the alloy:the first is the refinement of residualθ-phase(Al2Cu) particles leading to the lower micro-galvanic currents and reduced susceptibilities to pitting corrosion,the second is the mass of strain-induced crystalline defects providing more nucleation sites for the formation of more volume fractions of stable oxide film.

关键词： Al-Cu alloy equal-channel angular pressing pitting corrosion resistance ultrafine-grained particle