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A compact route for efficient production of high-purity β-Ga2O3 powder

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Rare Metals 2024年第9期43卷 4573-4584页

作者： Xiao-Wei Zhou Gao-Jie Chen Liang Xu Zhi-Jun Shao Cheng Yang Yong-Pan Tian Zhuo Zhao School of Metallurgical Engineering Anhui University of Technology low-carbon research institute Anhui University of Technology

The present study has proposed a compact process for the production of high-purity β-Ga2O3powder by simply using gallium metal and water as the raw materials. The process basically consists of two essential steps including hydrothermal synthesis of Ga OOH and calcination of Ga OOH for the production of the target product of β-Ga2O3. Thermodynamic evaluation and systematic experiments were conducted for process parameter optimization. X-ray diffractometer（XRD）, scanning electron microscopy（SEM）, thermogravimetryDdifferential scanning calorimetry（TG-DSC） and X-ray photoelectron spectroscopy（XPS） were utilized to clarify the reaction mechanisms of the hydrothermal synthesis and transformation of Ga OOH to β-Ga2O3by calcination. Chemical analysis of the final product of β-Ga2O3obtained under the optimal conditions was carried out with inductively coupled plasma mass spectrometry（ICP-MS）, and the results showed that the contents of the representative impurities such as Ni, Cu, In, Mn, Co, Zn and Cr are obviously lower than the requirement of 5N β-Ga2O3standard, exhibiting excellent application prospect of the proposed process to produce high-purity β-Ga2O3.

关键词： Calcination Hydrothermal synthesis Purity Reaction mechanism β-Ga2O3

Process metallurgy and data-driven prediction and feedback of blast furnace heat indicators

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1228-1240页

作者： Quan Shi Jue Tang Mansheng Chu School of Metallurgy Northeastern UniversityShenyang 110819China institute for Frontier Technologies of low-carbon Steelmaking Northeastern UniversityShenyang 110819China Engineering research Center of Frontier Technologies for low-carbon Steelmaking(Ministry of Education) Shenyang 110819China

The prediction and control of furnace heat indicators are of great importance for improving the heat levels and conditions of the complex and difficult-to-operate hour-class delay blast furnace(BF)*** this work,a prediction and feedback model of furnace heat indicators based on the fusion of data-driven and BF ironmaking processes was *** data on raw and fuel materials,process op-eration,smelting state,and slag and iron discharge during the whole BF process comprised 171 variables with 9223 groups of data and were comprehensively analyzed.A novel method for the delay analysis of furnace heat indicators was *** extracted delay variables were found to play an important role in *** method that combined the genetic algorithm and stacking efficiently im-proved performance compared with the traditional machine learning algorithm in improving the hit ratio of the furnace heat prediction *** hit ratio for predicting the temperature of hot metal in the error range of±10℃ was 92.4%,and that for the chemical heat of hot metal in the error range of±0.1wt%was 93.3%.On the basis of the furnace heat prediction model and expert experience,a feedback model of furnace heat operation was established to obtain quantitative operation suggestions for stabilizing BF heat *** sugges-tions were highly accepted by BF ***,the comprehensive and dynamic model proposed in this work was successfully ap-plied in a practical BF *** improved the BF temperature level remarkably,increasing the furnace temperature stability rate from 54.9%to 84.9%.This improvement achieved considerable economic benefits.

关键词： blast furnace furnace heat genetic algorithm stacking prediction and feedback

Influence of pore structure on thermal stress distribution inside coal particles during primary fragmentation

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Particuology 2024年第2期85卷 49-61页

作者： Kai Qiao Shan Zhong Siyang Tang Ke Yang Hairong Yue Kui Ma Lei Song Bin Liang School of Chemical Engineering Sichuan UniversityChengdu610065China institute of New Energy and low-carbon Technology Chengdu610207China

Thermal stress is an important reason of coal particle primary fragmentation,during which the role of pore structure is *** stress induced fragmentation experiments were conducted with low volatile coal/char particles,and the results show that the fragmentation severity enhances with increasing *** porous thermal stress models were developed with finite element method,and the influences of the pore shape,size,position and porosity on the thermal stress were *** maximum thermal stress inside particle increases with pore curvature,the pore position affects the thermal stress more significantly at the particle center and *** expectation of the maximum tensile thermal stress linearly increases with porosity,making the particles with higher porosity easier to fragment,contrary to the conclusion deduced from the devolatilization *** obtained results are valuable for the analysis of different thermal processes concerning the thermal stresses of the solid feedstocks.

关键词： Coal particle Primary fragmentation Thermal stress Pore structure Porosity

Effect of titanium on the sticking of pellets based on hydrogen metallurgy shaft furnace:Behavior analysis and mechanism evolution

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 282-291页

作者： Jinge Feng Jue Tang Zichuan Zhao Mansheng Chu Aijun Zheng Xiaobing Li Xiao’ai Wang School of Metallurgy Northeastern UniversityShenyang 110819China institute for Frontier Technologies of low-carbon Steelmaking Northeastern UniversityShenyang 110819China Liaoning low-carbon Steelmaking Technology Engineering research Center Northeastern UniversityShenyang 110819China Engineering research Center of Frontier Technologies for low-carbon Steelmaking(Ministry of Education Shenyang 110819China Zhang Xuan Technology of HBIS Group Co. Ltd.Shijiazhuang 050000China Xuanhua Iron and Steel Group Co. Ltd.Shijiazhuang 050000China Iron and Steel research institute of HBIS Group Co. Ltd.Shijiazhuang 050000China

Direct reduction based on hydrogen metallurgical gas-based shaft furnace is a promising technology for the efficient and low-carbon smelting of vanadium-titanium ***,in this process,the sticking of pellets occurs due to the aggregation of metal-lic iron between the contact surfaces of adjacent pellets and has a serious negative effect on the continuous *** paper presents a detailed experimental study of the effect of TiO2 on the sticking behavior of pellets during direct reduction under different *** showed that the sticking index(SI)decreased linearly with the increasing TiO2 *** phenomenon can be attributed to the increase in unreduced FeTiO3 during reduction,leading to a decrease in the number and strength of metallic iron interconnections at the sticking *** the TiO2 addition amount was raised from 0 to 15wt%at 1100°C,the SI also increased from 0.71%to 59.91%.The connection of the slag phase could be attributed to the sticking at a low reduction temperature,corresponding to the low sticking ***,the interconnection of metallic iron became the dominant factor,and the SI increased sharply with the increase in re-duction ***2 had a greater effect on SI at a high reduction temperature than at a low reduction temperature.

关键词： titanium sticking index hydrogen metallurgy direct reduction pellets

A justice and innovative way ahead of consumption-based emission accounting approach

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Science China Earth Sciences 2024年第9期67卷 2999-3010页

作者： Qun SHEN Hongbo DUAN Yun TANG Linbing TANG Li SHANG Xinyu DOU Wei WEI Weiqiang CHEN Zhu LIU State Key Laboratory of low carbon Catalysis and carbon Dioxide Utilization CAS Key Laboratory of Low-Carbon Conversion Science&EngineeringShanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China School of Economics&Management University of Chinese Academy of SciencesBeijing 100190China Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Department of Earth System Science Tsinghua UnivesityBeijing 100084China

carbon emission accounting is an important basis for global climate *** on the consumption-based accounting(CBA)method,the characteristics of carbon flow between national,regional,and product processes could be more clearly ***,CBA is more conducive to clarifying the attribution of responsibilities between producers and consumers,with the principles of fairness and *** accounting for carbon emissions in typical countries from 1990 to 2019,we found that the CBA emissions are higher than the production-based accounting(PBA)emissions in major developed countries,while the results are reversed for developing *** the past 30 years,the CBA emissions in targeted developed countries generally have shown a downward trend,while in developing countries,they have shown an upward *** emissions in China have shown a continuous growth trend from 1990 to 2019,but the pace has slowed down significantly over the last ***,the embodied carbon intensity of China’s exports continues to decline,indicating that China is providing more green and low-carbon products to the *** the PV industry as an example,this study further reveals the contribution of specific product industries to the country’s carbon transfer through product carbon footprint *** order to provide a scientific basis for global mitigation and climate governance,it is urgent to innovate a scientific,practical,and standardized CBA technology system.

关键词： Consumption-based accounting Production-based accounting carbon transfer carbon footprint

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Achieving simultaneously high conversion and high selectivity for light olefins directly producing from syngas

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Science China Chemistry 2024年第3期67卷 753-754页

作者： Yuhan Sun Shanxi research institute Huairou Research LaboratoryTaiyuan 030032China institute of carbon Neutrality ShanghaiTech UniversityShanghai 201210China

The activity and selectivity are two primary indexes of a successful catalyst for chemical reactions. However,achieving a high activity and a high selectivity simultaneously is a long-standing challenge in catalysis, the socalled activity-selectivity trade-off. In the article recently published in Science, a research team led by Prof.

关键词： selectivity simultaneous catalysis

Effect of ambient pressures on laser-induced breakdown spectroscopy signals

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Frontiers of physics 2024年第4期19卷 243-256页

作者： Kaifan Zhang Weiran Song Zongyu Hou Zhe Wang State Key Laboratory of Power System Operation and Control Tsinghua-Rio Tinto Joint Research Centre for ResourcesEnergy and Sustainable DevelopmentInternational Joint Laboratory on Low Carbon Clean Energy InnovationInstitute for Carbon NeutralityDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Shanxi research institute for Clean Energy Tsinghua UniversityTaiyuan 030032China

Laser-induced breakdown spectroscopy(LIBS)is regarded as the future superstar for analytical chemistry and widely applied in various *** the quality of LIBS signal is fundamental to achieving accurate quantification and large-scale commercialization of *** propose control methods that improve LIBS signal quality,it is essential to have a comprehensive understanding of the influence of key parameters,such as ambient gas pressure,temperature,and sample temperature on LIBS *** date,extensive research has been carried ***,different researchers often yield significantly different experimental results for LIBS,preventing the formation of consistent *** greatly prevents the understanding of influencing laws of key parameters and the improvement of LIBS quantitative *** ambient gas pressure as an example,this paper compares the effects of ambient gas pressure under different optimization conditions,reveals the influence of spatiotemporal window caused by inherent characteristics of LIBS signal sources,i.e.,intense temporal changes and spatial non-uniformity of laser-induced plasmas,on the impact patterns of key *** the perspective of plasma spatiotemporal evolution,the paper elucidates the influence patterns of ambient gas pressure on LIBS signals,clarifying seemingly contradictory research results in the literature.

关键词： laser-induced breakdown spectroscopy spatiotemporal window pressure condition signal uncertainty plasma modulation

Surface iodine and pyrenyl-graphdiyne co-modified Bi catalysts for highly efficient CO_(2) electroreduction in acidic electrolyte

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Nano research 2024年第4期17卷 2381-2387页

作者： Min Zhang Juan Wang Xin Rong Xiu-Li Lu Tong-Bu Lu MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China

CO_(2) electroreduction to formic acid/formate would contribute to alleviating the energy and climate *** work reports a Bi-based catalyst derived from the in-situ electroreduction of Bi_(2)O_(2)CO_(3) modified with iodine and pyrenyl-graphdiyne(PGDY)on the surface for efficient electroreduction of CO_(2) in acidic electrolyte,with a high partial current density of 98.71 mA·cm^(-2) and high Faradaic efficiency(FE)>90%over the potential range from^(-1).2 to-1.5 V *** hydrogen electrode(RHE),as well as the long-term operational stability over 240 h without degradation in H-type *** results and density function theory calculations show that the synergistic effect of surface iodine and PGDY is responsible for this active and extremely stable process of CO_(2) electroreduction via lowering the energy barriers for formation of*OCHO intermediate,suppressing the competitive HER by enhancing the concentration of both K+and CO_(2) at reaction interface,as well as preventing the dissolution and re-deposition of active Bi atoms on surface during catalytic *** work provides new insight into designing highly active and stable electrocatalysts for CO_(2) reduction.

关键词： CO_(2) reduction electrocatalysis Bi-based catalysts acidic electrolyte

Initial precursor reaction mechanism of CVD-HfC coating based on density functional theory

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Chinese Journal of Aeronautics 2024年第7期37卷 511-521页

作者： Yunzhou LIN Yulei ZHANG Yanqin FU Jian ZHANG Jing’an KONG Ruicong CHEN State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research CenterNorthwestern Polytechnical UniversityXi’an 710072China Henan Key Laboratory of High Performance carbon Fiber Reinforced Composites Carbon Matrix Composites Research InstituteHenan Academy of SciencesZhengzhou 450046China

Recently,the preparation of ultra-high temperature HfC ceramic coating has gained significant attention,particularly through the application of the HfCl_(4)-CH_(4)-H_(2)-Ar system via Chemical Vapor Deposition(CVD),which has been found widely applied to C/C ***,an analysis of the reactions that occur in the initial stage of the CVD-HfC coating process is presented using Density Functional Theory(DFT)and Transition State Theory(TST)at the B3LYP/Lanl2DZ *** results reveal that HfCl4 can only cleave to produce hypochlorite,which will further react with methyl to synthesize intermediates to form *** to the analysis of the energy barrier and reaction constant,HfCl preferentially reacts with methyl groups to form complex adsorptive intermediates at 1573 *** a C—Hf bond production energy of 212.8 kcal/mol(1 kcal=4.18 kJ),the reaction rate constant of HfCl+CH is calculated to be 2.15×10^(-18) cm^(3)/s at 1573 ***,both the simulation and experimental results exhibit that the upward trend of reaction rate constants with temperature is also consistent with the deposition rate,indicating that the growth curve of the reaction rate constants tends to flatten *** proposed reaction model of the precursor’s decomposition and reconstruction during deposition process has significant implication for the process guidance.

关键词： carbon composite HfC coating Chemical vapor deposition Density functional theory Precursor reaction mechanism