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Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 102-110页

作者： Qiang Liu Xiang Li Shen Du Ming Gao Yanbin Yin Jiongming Zhang state key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the *** which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid *** contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive ***,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding *** results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles *** addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually *** one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the *** findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

关键词： mold flux low basicity bubbles three-dimensional X-ray microscope viscosity

Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 39-48页

作者： Peng Li Meifeng Cai Shengjun Miao Yuan Li Yu Wang key laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China state key laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.

关键词： overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie Wang Wei Wang Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China key laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China state key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

Effect of wall boundary condition on CFD simulation of CFB risers

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Particuology 2013年第5期11卷 556-565页

作者： Xinyu Zhou Jinsen Gao Chunming Xu Xingying Lan state key laboratory of heavy oil Processing China University of Petroleum

The effect of solid-phase wall boundary condition on the numerical simulation of gas-solid flow in CFB risers containing FCC particles was investigated using the two-fluid model incorporating the kinetic the- ory of granular flow. Both the Gidaspow drag model and the EMMS-based drag model were used. The Johnson and Jackson （1987） wall boundary condition was applied to describe the interaction between particles and wall. Based on the experimental system of Li and Kwauk （1994）, parametric studies of spec- ularity coefficient （cp = 1.0, 0.6, 0.0005, 0.00005, 0） and particle-wall restitution coefficient （ew = 0.6, 0.9, 0.95, 0.99, 0.999） were performed to evaluate their effects on axial voidage profile, solids flux, meso-scale and heterogeneous structures. Simulation results showed that solid-phase wall boundary condition had little effect on axial voidage profile when the Gidaspow drag model was used. However, the specular- ity coefficient ~a had a pronounced influence on flow behavior when the EMMS-based drag model was used, and a small specularity coefficient （cp = 0.00005, 0） could result in better agreement with exper- imental data. The particle-wall restitution coefficient ew plays but a minor role in the holistic flow characteristics.

关键词： JCirculating fluidized bedBoundary conditionEMMSCFDSpecularity coefficientParticle-wall restitution coefficient

Macroporous perovskite-type complex oxide catalysts of La_(1-x)K_xCo_(1-y)Fe_yO_3 for diesel soot combustion

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Journal of Rare Earths 2009年第6期27卷 955-960页

作者：张桂臻赵震刘坚徐俊峰荆延妮段爱军姜桂元 state key laboratory of heavy oil Processing China University of Petroleum

A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution *** method could ensure the formation of the desired macroporous structures and the desired crystal phases of the prepared *** was found that the macroporous catalysts showed higher catalytic activities for soot combustion than that of the corresponding nanometric samples,and the macroporous ...

关键词： macroporous perovskite-type oxides diesel engine exhaust soot catalytic combustion rare earths

Preparation of ultrafine Ce-based oxide nanoparticles and their catalytic performances for diesel soot combustion

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Journal of Rare Earths 2014年第2期32卷 124-130页

作者：韦岳长赵震焦金庆刘坚段爱军姜桂元 state key laboratory of heavy oil Processing China University of Petroleum

The ultrafine Ce-based oxide nanoparticles with different element dopings （Zr, Y） were synthesized by the method of mi- cropores-diffused coprecipitation （MDC） using ammonia solution as the precipitation agent. The activities of the catalysts for soot oxidation were evaluated by the temperature-programmed oxidation （TPO） reaction. Ce-based oxides prepared in this study exhibited high catalytic activity for soot oxidation under tile condition of loose contact between soot particles and catalysts, and the catalytic ac- tivity ofultrafine ***0 iO2 nanoparticle for soot combustion was the highest, whose/＂10, Ts0 and Sco2m was 364, 442 ~C and 98.3%, respectively. All catalysts were systematically characterized by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brumauer-Emett-Teller （BET）, Fourier transform infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectroscopy （UV-Vis DRS）. It was indicated that the MDC method could prepare the ultrafine Ce-bascd oxide nanoparticles whose the crystal lattice were perfect, and the BET surface area and average crystal size of the ultrafine nanoparticles changed with the different element dopings （Zr, Y）. The H2-TPR measurements showed that the ultrafine Ce-based ox- ide nanoparticles with the doping-Zr cation could be favorable for improving the redox property of the catalysts.

关键词： ultrafine nanoparticles Ce-based oxides catalysts soot combustion micropores-diffused coprecipitation rare earths

Effects of Cs-substitution and partial reduction on catalytic performance of Keggin-type phosphomolybdic polyoxometalates for selective oxidation of isobutane

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Journal of Energy Chemistry 2016年第1期25卷 85-92页

作者： Shizhe Liu Lu Chen Guowei Wang Jianwei Liu Yanan Gao Chunyi Li Honghong Shan state key laboratory of heavy oil Processing China University of Petroleum

The catalytic performance of Cs-substituted phosphomolybdic salts was studied for selective oxidation of isobutane. The results of activity tests revealed that 360 °C was the optimal reaction temperature. It was demonstrated that oxidizing sites not only took dominating part in the activation of isobutane, but also influenced the product distribution. Besides, appropriate Cs addition led to moderate acidity of catalysts, favoring the selectivity to desired products. Furthermore, to obtain partially reduced catalysts, different calcination atmospheres were investigated and certain proportion of Mo^（5＋） produced during calcination was crucial for the redox reaction. The catalyst calcined in N2 showed the highest yield of MAA（7.0%）. Fe-substitution enhanced the activity of catalysts by rapid reoxidation of Mo^（5＋）.

关键词： Isobutane Selective oxidation Methacrylic acid Polyoxometalate

CeO_2-supported vanadium oxide catalysts for soot oxidation:the roles of molecular structure and nanometer effect

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Journal of Rare Earths 2010年第2期28卷 198-204页

作者：刘坚赵震徐春明段爱军姜桂元 state key laboratory of heavy oil Processing China University of Petroleum

The nanometer CeO2 powder was prepared by the method of microwave-assisted heating hydrolysis,and the nanometer CeO2-supported or ordinary CeO2-supported vanadia catalysts with different vanadium loadings(atomic ratios:100V/Ce=0.1,1,4,10,and 20) were prepared by an incipient-wetness impregnation *** techniques(XRD,FT-IR,Raman and UV-Vis DRS) were utilized to characterize the structures of VOx/CeO2 *** results showed that the structures of CeO2-supported vanadium oxide catalysts de...

关键词： vanadium oxide catalyst CeO2 nanometer soot combustion rare earths

Reduced graphene oxide supported Pd-Cu-Co trimetallic catalyst:synthesis,characterization and methanol electrooxidation properties

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Journal of Energy Chemistry 2019年第2期28卷 72-78页

作者： Fan Yang Bing Zhang Sen Dong Chunxia Wang Andong Feng Xiaoxu Fan Yongfeng Li state key laboratory of heavy oil Processing China University of Petroleum

Trimetallic palladium-copper-cobalt nanoparticles supported on reduced graphene oxide(PdCuCo/RGO)with different molar ratios of Pd,Cu and Co can be synthesized by facile chemical reduction with NaBH_4 as reductant and cetrimonium bromide as *** morphology,structure and composition of the as-synthesized catalysts are characterized by transmission electron microscopy,X-ray diffraction and Xray photoelectron *** cyclic voltammetry and chronoamperometry are utilized to investigate the electrochemical activities and stabilities of the as-obtained *** results demonstrate that the PdCuCo/RGO catalyst shows superior catalytic activity and stability for methanol electrooxidation in alkaline media compared with PdCu/RGO,PdCo/RGO,and Pd/RGO *** findings suggest that the PdCuCo/RGO catalyst possesses a great potential as a promising anode catalyst for direct methanol fuel cells.

关键词： Trimetallic nanoparticles Reduced graphene oxide Methanol oxidation