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Description of martensitic transformation kinetics in Fe-C-X(X = Ni,Cr,Mn,Si) system by a modified model

International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1026-1036页

作者： Xiyuan Geng Hongcan Chen Jingjing wang Yu Zhang Qun Luo qian Li State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Ansteel Beijing Research Institute Co. LtdBeijing 102211China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

Controlling the content of athermal martensite and retained austenite is important to improving the mechanical properties of high-strength steels,but a mechanism for the accurate description of martensitic transformation during the cooling process must be *** present,frequently used semi-empirical kinetics models suffer from huge errors at the beginning of transformation,and most of them fail to exhibit the sigmoidal shape characteristic of transformation *** describe the martensitic transformation process accurately,based on the Magee model,we introduced the changes in the nucleation activation energy of martensite with temperature,which led to the varying nucleation rates of this model during martensitic *** to the calculation results,the relative error of the modified model for the martensitic transformation kinetics curves of Fe-C-X(X = Ni,Cr,Mn,Si) alloys reached 9.5% compared with those measured via the thermal expansion *** relative error was approximately reduced by two-thirds compared with that of the Magee *** incorporation of nucleation activation energy into the kinetics model contributes to the improvement of its precision.

关键词： Fe-C-X system martensitic transformation kinetics curve semi-empirical model nucleation activation energy

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Research progress of CO_(2) capture and mineralization based on natural minerals

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1208-1227页

作者： Chenguang qian Chunquan Li Peng Huang Jialin Liang Xin Zhang Jifa wang Jianbing wang Zhiming Sun School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China Shanghai Construction Building Material Technology Group Shanghai 200080China

Natural minerals,such as kaolinite,halloysite,montmorillonite,attapulgite,bentonite,sepiolite,forsterite,and wollastonite,have considerable potential for use in CO_(2) capture and mineralization due to their abundant reserves,low cost,excellent mechanical prop-erties,and chemical *** the past decades,various methods,such as those involving heat,acid,alkali,organic amine,amino sil-ane,and ionic liquid,have been employed to enhance the CO_(2) capture performance of natural minerals to attain high specific surface area,a large number of pore structures,and rich active *** research on CO_(2) capture by natural minerals will focus on the full utiliza-tion of the properties of natural minerals,adoption of suitable modification methods,and preparation of composite materials with high specific surface area and rich active *** addition,we provide a summary of the principle and technical route of direct and indirect mineralization of CO_(2) by natural *** process uses minerals with high calcium and magnesium contents,such as forsterite(Mg_(2)SiO_(4)),serpentine[Mg_(3)Si_(2)O(OH)_(4)],and wollastonite(CaSiO_(3)).The research status of indirect mineralization of CO_(2) using hydro-chloric acid,acetic acid,molten salt,and ammonium salt as media is also introduced in *** recovery of additives and high-value-added products during the mineralization process to increase economic benefits is another focus of future research on CO_(2) mineralization by natural minerals.

关键词： natural mineral carbon dioxide capture modification composite material carbon dioxide mineralization

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Electrocatalytic performance of CNTs/graphene composited rare earth phthalocyanines(M=La,Y,Yb,Sc)

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Journal of Rare Earths 2024年第2期42卷 323-333,I0004页

作者： Tingting Jiang Caixia Ou Luyi wang Jun Chen Sydorov Dmytro qian Zhang Jintian Luo Hua wang Jiangxi Key Laboratory of Power Batteries and Materials Faculty of Materials Metallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou341000China Joint Department of Electrochemical Energy Systems Institute of Bioorganic Chemistry and PetrochemistryNational Academy of Sciences of Ukraine38A VernadskyAveKiev03142Ukraine Guangdong Jiana Energy Technology Co. Ltd.Qingyuan511500China

In this study,a class of rare earth composite sandwich phthalocyanines(MPcs,M=La,Y,Yb,Sc) were prepared and compounded with graphene and carbon nanotubes to obtain MPc/Gr and MPc/CNTs *** electrocatalytic behaviors of MPc/Gr and MPc/CNTs electrodes were further *** results show that the central rare earth metal has a large influence on the electrocatalytic *** the MPcs/Gr samples,ScPc with the smallest ionic radius and molecular size can be more uniformly dispersed in graphene,and the hydrogen precipitation overpotential of ScPc/Gr electrode is514 mV,corresponding to a Tafel slope of 148 mV/dec,with better electrocatalytic performance than other rare earth metal *** for the MPc/CNTs composites,LaPc,which has the largest ionic radius and molecular size,is more uniformly dispersed on the surface of CNTs,so that the LaPc/CNT electrode exhibits the best LSV performance with the smallest corresponding Tafel slope(176 mV/dec).The main reason is the different binding modes of MPcs molecules in Gr and *** rare earth phthalocyanine is combined with layered graphene,the smallest size of rare earth phthalocyanine(ScPc)is more easily embedded in the graphene layer,resulting in better homogeneity of the composite,larger effective contact area and better electrocatalytic *** contrast,when rare earth phthalocyanine is bound to carbon nanotubes in a tubular structure,it is mainly bound by attaching to the surface or being entangled by the carbon *** this case,the rare-earth phthalocyanine molecules(LaPc)with larger layer spacing can provide more contact area with CNTs,forming a more uniform and effective composite,which eventually provides more active sites and better electrocatalytic performance.

关键词： Electrocatalysis Rare earth phthalocyanines Graphene(Gr) Carbon nanotubes(CNTs) Composite

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Uncertainty quantification of mechanism motion based on coupled mechanism—motor dynamic model for ammunition delivery system

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Defence Technology（防务技术） 2024年第3期33卷 125-133页

作者： Jinsong Tang Linfang qian Longmiao Chen Guangsong Chen mingming wang Guangzu Zhou Nanjing University of Science and Technology Nanjing 210094China Northwest Institute of Mechanical and Electrical Engineering Xianyang 712099China

In this paper,a dynamic modeling method of motor driven electromechanical system is presented,and the uncertainty quantification of mechanism motion is investigated based on this *** main contribution is to propose a novel mechanism-motor coupling dynamic modeling method,in which the relationship between mechanism motion and motor rotation is established according to the geometric coordination of the *** advantages of this include establishing intuitive coupling between the mechanism and motor,facilitating the discussion for the influence of both mechanical and electrical parameters on the mechanism,and enabling dynamic simulation with controller to take the randomness of the electric load into *** simulation considering feedback control of ammunition delivery system is carried out,and the feasibility of the model is verified *** on probability density evolution theory,we comprehensively discuss the effects of system parameters on mechanism motion from the perspective of uncertainty *** work can not only provide guidance for engineering design of ammunition delivery mechanism,but also provide theoretical support for modeling and uncertainty quantification research of mechatronics system.

关键词： Ammunition delivery system Electromechanical coupling dynamics Uncertainty quantification Generalized probability density evolution

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Advances of Synergistic Electrocatalysis Between Single Atoms and Nanoparticles/Clusters

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Nano-Micro Letters 2024年第11期16卷 377-412页

作者： Guanyu Luo Min Song qian Zhang Lulu An Tao Shen Shuang wang Hanyu Hu Xiao Huang Deli wang Key Laboratory of Material Chemistry for Energy Conversion and Storage(Huazhong University of Science and Technology)Ministry of Education School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Combining single atoms with clusters or nanoparticles is an emerging tactic to design efficient *** synergy effect and high atomic utilization of active sites in the composite catalysts result in enhanced electrocatalytic performance,simultaneously provide a radical analysis of the interrelationship between structure and *** this review,the recent advances of single-atomic site catalysts coupled with clusters or nanoparticles are ***,the synthetic strategies,characterization,dynamics and types of single atoms coupled with clusters/nanoparticles are introduced,and then the key factors controlling the structure of the composite catalysts are ***,several clean energy catalytic reactions performed over the synergistic composite catalysts are ***,the encountering challenges and recommendations for the future advancement of synergistic structure in energy-transformation electrocatalysis are outlined.

关键词： Single atoms Nanoparticles Clusters Synergistic composite catalysts Synergistic effect

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Impact factors and pathways of halonitromethanes formation from aspartic acid during LED-UV_(265)/chlorine disinfection

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Frontiers of Environmental Science & Engineering 2024年第1期18卷 129-144页

作者： Liangwen Zhu Tao wang qian Tang Qing wang Lin Deng Jun Hu Chaoqun Tan Rajendra Prasad Singh Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education School of Civil EngineeringSoutheast UniversityNanjing 211189China College of Environment Zhejiang University of TechnologyHangzhou 310014China

Light emitting diode (LED-UV)/chlorine disinfection can replace UV/chlorine disinfection in wastewater treatment plants and water supply plants. Halonitromethanes (HNMs) are a class of novel nitrogenous disinfection by-products, which are characterized by higher cytotoxicity and genotoxicity than regulated disinfection by-products. Herein, the impact factors and pathways of HNMs formation from aspartic acid (ASP) were investigated during LED-UV_(265)/chlorine disinfection. The results showed that three types of chlorinated-HNMs (Cl-HNMs) were found during LED-UV265/chlorine disinfection, and their concentrations increased first and then declined as the reaction progressed. Cl-HNMs yields increased with increasing LED-UV_(265) intensity, free chlorine dosage, and ASP concentration, which declined with increasing pH (6.0–8.0). Meantime, the important impact of the coexisting ions contained in water matrices on HNMs formation from ASP was observed during LED-UV_(265)/chlorine disinfection. It was found that copper ions (Cu^(2+)) promoted Cl-HNMs formation. Furthermore, when bromide (Br–) appeared during LED-UV265/chlorine disinfection, nine types of HNMs were detected simultaneously. Moreover, Br– not only converted Cl-HNMs toward brominated (chlorinated)-HNMs and brominated-HNMs but also showed a marked effect on HNMs concentrations and species. Subsequently, the possible pathways of HNMs formation from ASP were proposed during LED-UV_(265)/chlorine disinfection. At last, it was proved that the formation trends of HNMs obtained in the real waters were similar to those in simulated waters. This work elaborated on the influence factors and pathways of HNMs formation, which is conducive to controlling the HNMs produced during LED-UV_(265)/chlorine disinfection.

关键词： LED-UV265 chlorine HNMs Aspartic acid Bromide Copper ions

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Mn single-atoms decorated CNT electrodes for high-performance supercapacitors

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Nano Research 2024年第5期17卷 4039-4046页

作者： qian Rong Chao Yuwen Yingkai Liu Yuanrong Liu Chunyang wang Yang wang Ding Zhang Zhen Wen Yunnan Key Laboratory of Opto-Electronic Information Technology Institute of Physics and Electronic InformationYunnan Normal UniversityKunming 650500China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Department of Physics and Astronomy University of CaliforniaIrvineCA 92697USA School of Materials Science and Engineering National Institute for Advanced MaterialsSmart Sensing Interdisciplinary Science CenterNankai UniversityTianjin 300350China Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Institute of Functional Nano and Soft Materials(FUNSOM)Soochow UniversitySuzhou 215123China

Developing highly robust and efficient electrode materials is of critical importance to promoting the energy density of current supercapacitors for ***,we report an efficient catalyst with monodispersed Mn single-atoms embedded in carbon nanotubes(Mn-CNTs)for enhancing the electrode performance of supercapacitors.A high specific capacitance(1523.6 F·g^(-1) at 1.0 A·g^(-1))can be achieved,which is about twice as high as the specific capacitance of the electrode material without the introduction of Mn ***,the asymmetric electrochemical capacitor created with Mn-CNT and activated carbon exhibits a high energy density of 180.8 Wh·kg^(-1) at a power density of 1.4 kW·kg^(-1),much higher than most reported *** study shows that the integration of Mn atoms into the CNT can enhance the charge transport capacity and the number of polar active sites of Mn-CNT and then facilitate chemical interactions between Mn-CNT and OH-.This work provides a novel strategy to enable high-energy storage in supercapacitors by introducing single-atoms into carbon nanotubes to improve electrodes’energy density and cycle life.

关键词： carbon nanotube(CNT) supercapacitor single-atoms power density energy density

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Nanoscopic tribological characteristics of a cryogenically cycled Zr-based metallic glass

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 113-126页

作者： qian Jia Qiaosheng Xia Qing Zhou Yucheng wang Yue Ren Yu Meng Haifeng wang Feng Zhou State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Surface Engineering and Remanufacturing Xi’an UniversityXi’an 710065China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Optimized macroscopic tribological behavior can be anticipated in metallic glasses(MGs)by cryogenic cycling treatment(CCT),which is attributed to enhanced ***,the intrinsic friction mechanisms of MGs induced by cryogenic rejuvenation are still poorly *** the present study,nanoscopic wear tests were conducted on the Zr-based MGs surface with different CCT cycles using atomic force microscopy(AFM).After CCT treatment with 100 cycles,the MG displays the highest adhesion and ploughing frictions,but significantly improved anti-wear *** tests and molecular dynamics simulations disclose that the increased adhesion is attributed to the dominance of liquid-like regions in the CCT-treated MGs,and the impact of reduced hardness and weak elastic recovery results in the deteriorated ploughing *** enhanced plasticity effectively dissipates the strain from the AFM tip through multiple shear bands and weakens the adhesion during deformation,giving rise to excellent wear *** study elucidates the promoting effect of CCT on the outstanding antiwear performance of MGs,and is helpful for the development of novel alloys.

关键词： metallic glasses cryogenic cycling treatment nanoscope wear friction mechanism

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QoS Routing Optimization Based on Deep Reinforcement Learning in SDN

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Computers, Materials & Continua 2024年第5期79卷 3007-3021页

作者： Yu Song Xusheng qian Nan Zhang Wei wang Ao Xiong State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China Marketing Service Center State Grid Jiangsu Electric Power Co.Ltd.Nanjing220000China Customer Service Center State Grid Co.Ltd.Nanjing211161China

To enhance the efficiency and expediency of issuing e-licenses within the power sector, we must confront thechallenge of managing the surging demand for data traffic. Within this realm, the network imposes stringentQuality of Service (QoS) requirements, revealing the inadequacies of traditional routing allocation mechanismsin accommodating such extensive data flows. In response to the imperative of handling a substantial influx of datarequests promptly and alleviating the constraints of existing technologies and network congestion, we present anarchitecture forQoS routing optimizationwith in SoftwareDefinedNetwork (SDN), leveraging deep reinforcementlearning. This innovative approach entails the separation of SDN control and transmission functionalities, centralizingcontrol over data forwardingwhile integrating deep reinforcement learning for informed routing decisions. Byfactoring in considerations such as delay, bandwidth, jitter rate, and packet loss rate, we design a reward function toguide theDeepDeterministic PolicyGradient (DDPG) algorithmin learning the optimal routing strategy to furnishsuperior QoS provision. In our empirical investigations, we juxtapose the performance of Deep ReinforcementLearning (DRL) against that of Shortest Path (SP) algorithms in terms of data packet transmission delay. Theexperimental simulation results show that our proposed algorithm has significant efficacy in reducing networkdelay and improving the overall transmission efficiency, which is superior to the traditional methods.

关键词： Deep reinforcement learning SDN route optimization QoS

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Research on the Generation Mechanism and Suppression Method of Aerodynamic Noise in Expansion Cavity Based on Hybrid Method

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2747-2772页

作者： Haitao Liu Jiaming wang Xiuliang Zhang Yanji Jiang qian Xiao School of Mechanotronics and Vehicle Engineering East China Jiaotong UniversityNanchang330013China Suzhou Automotive Research Institue Tsinghua UniversitySuzhou215131China

The expansion chamber serves as the primary silencing structure within the exhaust ***,it can also act as a sound-emitting structure when subjected to *** article presents a hybrid method for numerically simulating and analyzing the unsteady flow and aerodynamic noise in an expansion chamber under the influence of airflow.A fluid simulation model is established,utilizing the Large Eddy Simulation(LES)method to calculate the unsteady flow within the expansion *** simulation results effectively capture the development and changes of the unsteady flow and vorticity inside the cavity,exhibiting a high level of consistency with experimental *** calculate the aerodynamic noise sources within the cavity,the flow field results are integrated using the method of integral interpolation and inserted into the acoustic *** acoustic analogy method is then employed to determine the aerodynamic noise *** acoustic simulation model is established,and the flow noise source is imported into the sound field grid to calculate the sound pressure at the far-field response *** calculated sound pressure levels and resonance frequencies show good agreement with the experimental *** address the issue of airflow regeneration noise within the cavity,perforated tubes are selected as a means of noise *** experimental platformfor airflow regeneration noise is constructed,and experimental samples are processed to analyze and verify the noise suppression effect of perforated tube expansion cavities under different airflow *** research findings indicate that the perforated tube expansion cavity can effectively suppress low-frequency aerodynamic noise within the cavity by impeding the formation of strong shear ***,the semi-perforated tube expansion cavity demonstrates the most effective suppression of aerodynamic noise.

关键词： Expansion cavity aerodynamic noise numerical simulation hybrid method perforated tube

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