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Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

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Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie Xue-yuan Jiang Hai-yan Tang ·Gen Li yu-hang Wang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel Institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

Fe-N-C core-shell catalysts with single low-spin Fe(Ⅱ)-N_(4)species for oxygen reduction reaction and high-performance proton exchange membrane fuel cells

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Journal of Energy Chemistry 2024年第6期93卷 538-546,I0013页

作者： yan Wan Linhui yu Bingxin yang Caihong Li Chen Fang Wei Guo Fang-Xing Xiao yangming Lin Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021FujianChina CAS Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021FujianChina Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350002FujianChina College of Materials Science and Engineering Fuzhou UniversityNew CampusMinhou 350108FujianChina College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117FujianChina

Fe-N-doped carbon materials(Fe-N-C)are promising candidates for oxygen reduction reaction(ORR)relative to Pt-based catalysts in proton exchange membrane fuel cells(PEMFCs).However,the intrinsic contributions of Fe-N_(4)moiety with different chemical/spin states(e.g.D1,D2,D3)to ORR are unclear since various states coexist *** the present work,Fe-N-C core-shell nanocatalyst with single lowspin Fe(Ⅱ)-N_(4)species(D1)is synthesized and identified with ex-situ ultralow temperature Mossbauer spectroscopy(T=1.6 K)that could essentially differentiate various Fe-N_(4)states and invisible Fe-O *** quantifying with CO-pulse chemisorption,site density and turnover frequency of Fe-N-C catalysts reach 2.4×10^(-9)site g^(-1)and 23 e site~(-1)s^(-1)during the ORR,***-wave potential(0.915V_(RHE))of the Fe-N-C catalyst is more positive(approximately 54 mV)than that of Pt/***,we observe that the performance of PEMFCs on Fe-N-C almost achieves the 2025 target of the US Department of Energy by demonstrating a current density of 1.037 A cm^(-2)combined with the peak power density of 0,685 W cm^(-2),suggesting the critical role of Fe(Ⅱ)-N_(4)site(D1).After 500 h of running,PEMFCs still deliver a power density of 1.26 W cm^(-2)at 1.0 bar H_(2)-O_(2),An unexpected rate-determining step is figured out by isotopic labelling experiment and theoretical *** work not only offers valuable insights regarding the intrinsic contribution of Fe-N_(4)with a single spin state to alkaline/acidic ORR,but also provides great opportunities for developing high-performance stable PEMFCs.

关键词： Fuel cells Oxygen reduction reaction Non-platinum group metals(PGMs) Isotopic labelling Active site TOF

Sustainable and practical semi-heterogeneous photosynthesis of 5-amino-1,2,4-thiadiazoles over WS_(2)/TEMPO

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Chinese Chemical Letters 2024年第8期35卷 250-253页

作者： Jia-Cheng Hou Hong-Tao Ji yu-Han Lu Jia-Sheng Wang Yao-Dan Xu yan-yan Zeng Wei-Min He School of Chemistry and Chemical Engineering University of South ChinaHengyang 421001China

An eco-friendly and practical method for the clean preparation of 5-amino-1,2,4-thiadiazoles was *** WS_(2)as the semiconductor photocatalyst,both TEMPO and O_(2)(in air)as the redox catalysts,a variety of thiadiazoles were semi-heterogeneously formed in high to quantitative yields and could be easily collected by CPME extraction and ***,the catalytic system can be reusable for at least 5 reaction runs.

关键词： Green chemistry Thiadiazoles Heterogeneous catalyst Redox catalyst Extraction

Understanding the spatial interaction of ultrasounds based on three-dimensional dual-frequency ultrasonic field numerical simulation

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China Foundry 2024年第1期21卷 29-43页

作者： Zhao-yang Yin Qi-chi Le yan-chao Jiang Da-zhi Zhao Qi-yu Liao Qi Zou Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

A transient 3D model was established to investigate the effect of spatial interaction of ultrasounds on the dual-frequency ultrasonic field in magnesium alloy *** effects of insertion depth and tip shape of the ultrasonic rods,input pressures and their ratio on the acoustic field distribution were discussed in ***,the spacing,angle,and insertion depth of two ultrasonic rods significantly affect the interaction between distinct *** a result,various acoustic pressure distributions and cavitation regions are *** spherical rods mitigate the longitudinal and transversal attenuation of acoustic pressure and expand the cavitation volume by 53.7%and 31.7%,respectively,compared to the plate and conical *** the input pressure will enlarge the cavitation region but has no effect on the acoustic pressure distribution *** acoustic pressure ratio significantly affects the pressure distribution and the cavitation region,and the best cavitation effect is obtained at the ratio of 2:1(P15:P20).

关键词： dual-frequency ultrasonic numerical model acoustic pressure spatial interaction magnesium alloy

Mold breakout prediction based on computer vision and machine learning

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Journal of Iron and Steel Research International 2024年第8期31卷 1947-1959页

作者： yan-yu Wang Qi-can Wang Yong-chang Zhang Yong-hui Cheng Man Yao Xu-dong Wang School of Materials Science and Engineering Dalian University of TechnologyDalian 116024LiaoningChina Key Laboratory of Solidification Control and Digital Preparation Technology Dalian University of TechnologyDalian 116024LiaoningChina

Breakout is the most serious production accident in continuous casting and must be detected and predicted by stable and reliable *** sticking region,which forms on the local copper plate and expanded into a"V"shape,is the typical precursor of ***,computer vision technology was exploited to visualize the temperature change rate of the copper plate based on the temperature signals from thermocouples;then,the static and dynamic features of the abnormal sticking region were ***,logistic regression and Adaboost models were used to study and identify these features,resulting in the development of a mold breakout prediction model based on computer vision and machine *** test results demonstrate that the proposed model can effectively distinguish anomalous temperature patterns and considerably reduce false alarms without any missing *** a result,the proposed method could offer valuable insights into the realm of abnormality detection and prediction during continuous casting process.

关键词： Abnormality detection Image processing Adaboost Logistic regression Continuous casting

Hydrophobic modification of polysaccharides and the construction and properties of their micelles:a review of applications in the field of biomedicine

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Science China Chemistry 2024年第6期67卷 1881-1903页

作者： Dayang Wang Xiaohua Li Huanchen Yao Xin Liu yan Gao Hailin Cong Bing yu Youqing Shen College of Chemistry and Chemical Engineering College of Life SciencesCollege of Materials Science and EngineeringInstitute of Biomedical Materials and EngineeringQingdao UniversityQingdao266071China State Key Laboratory of Bio-Fibers and Eco-Textiles Qingdao UniversityQingdao266071China School of Materials Science and Engineering Shandong University of TechnologyZibo255000China Key Laboratory of Biomass Chemical Engineering of Ministry of Education Center for Bionanoengineeringand Department of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China

Nanomedicine delivery technology plays an important role in modern medicine and has shown good therapeutic effects in scientific *** have the characteristics of wide sources,excellent biocompatibility,and *** addition,there are multifunctional groups on the main chain of polysaccharides,which can be surface-modified or functionalized to have targeting ability through specific sugar *** polysaccharide micelles with good biocompatibility,degradability,high safety,easy structural modification,and special core-shell structure are regarded as ideal carriers for ***,this review is focused on the hydrophobic modification designs of polysaccharides,the preparation methods and characteristics of micelles,and the applications of amphiphilic polysaccharide micelles in the field of *** is expected to provide some ideas and inspiration for the design of polysaccharide drug carriers.

关键词： polysaccharide hydrophobic modification micelle drug delivery biomedicine

Configuring single-layer MXene nanosheet onto natural wood fiber via C-Ti-C covalent bonds for high-stability Li-S batteries

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Journal of Energy Chemistry 2024年第8期95卷 701-711,I0016页

作者： yangyang Chen yu Liao Ying Wu Lei Li Zhen Zhang Sha Luo Yiqiang Wu yan Qing College of Materials Science and Technology Central South University of Forestry and TechnologyChangsha 410004HunanChina

Lithium-sulfur batteries(LSBs)are considered promising candidates for next-generation battery technologies owing to their outstanding theoretical energy density and ***,the low conductivity and polysulfide shuttling effect of S cathodes severely hamper the practical performance of ***,in situ-generated single layer MXene nanosheet/hierarchical porous carbonized wood fiber(MX/PCWF)composites are prepared via a nonhazardous eutectic activation strategy coupled with pyrolysis-induced gas *** unique architecture,wherein single layer MXene nanosheets are constructed on carbonized wood fiber walls,ensures rapid polysulfide conversion and continuous electron transfer for redox *** C-Ti-C bonds formed between MXene and PCWF can considerably expedite the conversion of polysulfides,effectively suppressing the shuttle *** impressive capacity of 1301.1 m A h g^(-1)at 0.5 C accompanied by remarkable stability is attained with the MX/PCWF host,as evidenced by the capacity maintenance of 722.6 m A h g^(-1)after 500 ***,the MX/PCWF/S cathode can still deliver a high capacity of 886.8 m A h g^(-1)at a high S loading of 5.6 mg cm^(-2).The construction of two-dimensional MXenes on natural wood fiber walls offers a competitive edge over S-based cathode materials and demonstrates a novel strategy for developing high-performance batteries.

关键词： Lithium-sulfur batteries S cathodes MXene nanosheets Wood fiber C-Ti-C bonds

Research of simulation and experiment on arc characteristics of gas mechanical switch

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HIGH VOLTAGE 2024年第3期9卷 626-635页

作者： Jiang, Cheng Qu, Lu yu, Zhangqing Gan, Zhizheng yan, Xin Zeng, Rong Huang, yulong Li, Shaofu Tsinghua Univ Dept Elect Engn Beijing Peoples R China Southwest Univ Sci & Technol Sch Informat Engn Mianyang Peoples R China Tsinghua Univ Sichuan Energy Internet Res Inst Chengdu Peoples R China

An arc is the high-temperature discharge plasma produced in the opening process of mechanical switches, which directly affects the breaking capability of a hybrid DC circuit breaker. According to the physical mechanism of an electric arc, the construction of an arc model for simulation analysis is an important technical means in the electrical field. In this study, based on the theory of magneto hydrodynamics (MHD), a gas mechanical switch model of a natural commutation DC circuit breaker with a compound gap is established. The arc motion process under different conditions is simulated and calculated. The influence of different initial pressures, different opening speeds, and different striking currents on the arc voltage characteristics is analysed. The results show that the larger the gas pressure, the smaller the arc volume and the higher the arc voltage. The faster the opening speed, the longer the arc and the higher the arc voltage; with the increase of the current, the arc voltage increases rapidly at a low current, while the arc voltage increases slowly at a high current.

关键词： CIRCUIT-BREAKER COEFFICIENTS

A bifunctional nitrile additive for high-performance lithiumoxygen batteries

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Nano Research 2024年第7期17卷 6119-6126页

作者： Ziwei Li yue yu Dongyue yang Jin Wang Junmin yan Gang Huang Tong Liu Xinbo Zhang Key Laboratory of Automobile Materials Ministry of EducationDepartment of Materials Science and EngineeringJilin UniversityChangchun 130022China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Chemistry and Waterloo Institute for Nanotechnology University of Waterloo200 University Ave.W.WaterlooOntario N2L 3G1Canada School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Li-O_(2)batteries with high energy density hold significant promise as next-generation energy storage ***,Li-O_(2)batteries have poor cycling performance at high current densities and large capacities,primarily due to the high impedance caused by the instability of the lithium anode and the sluggish kinetics in the discharge products decomposition on the ***,we investigated a bifunctional nitrile additive(2-methoxy benzonitrile(2-MBN))with good chemical/electrochemical stability to improve the performances of Li-O_(2)*** 2-MBN could actively modify the anode by ensuring uniform Li+deposition and optimizing the composition of solid electrolyte interphase(SEI).Meanwhile,it could also facilitate the decomposition of discharge products by inducing the formation of sheet-like Li_(2)O_(2),significantly reducing the battery charge *** bifunctional effects of 2-MBN for the anode and cathode enable Li-O_(2)batteries to achieve a stable lifetime of 97 cycles at a current density of 600 mA·g^(−1)with a fixed capacity of 2000 mAh·g^(−1),much better than that of Li-O_(2)batteries without 2-MBN(28 cycles).The inclusion of 2-MBN provides an effective approach for attaining high-performance Li-O_(2)batteries.

关键词： nitrile additives Li-O_(2)batteries lithium metal anode charge overpotential