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Numerical investigation of turbulent flow behavior of sand particles in core shooting process

Procedia Manufacturing 2019年 37卷 182-189页

作者： Lele Tong Xu Shen Jianxin Zhou Yajun Yin Xiaoyuan Ji Huazhong University of Science and Technology State Key Laboratory of Materials Processing and Die &Mould Technology Wuhan 430074 China

The core shooting process is the most widely used technology on sand core making and plays an important role on the quality of sand cores. However, the core shooting process has a complexity flow behavior of sand particles. In the current work, a computational fluid dynamics model- two-fluid model with incorporating the kinetic theory was adopted to investigate the hydrodynamic flow behavior of sand particles in sand shooting process. A comparison between laminar and turbulence model was made. The simulation results indicate that the turbulent flow has a significant effect on sand particles flow. The fluctuation of kinetic energy contributes to turbulent flow has a great effect on the sand volume distribution. A difference of sand volume fraction between wall and center of sand box occurs in turbulence model. The variation of solid velocity is nearly the same in both laminar and turbulence *** variation of gas velocity has a more significant effect by different turbulence model than particle phase.

关键词： sand core shooting two-fluid model turbulent flow kinetic theory turbulent flow solid velocity

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Low-coordination Nanocrystalline Copper-based Catalysts through Theory-guided Electrochemical Restructuring for Selective CO2Reduction to Ethylene

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Angewandte Chemie 2024年第16期136卷

作者： Wensheng Fang Ruihu Lu Fu-Min Li Chaohui He Dan Wu Kaihang Yue Yu Mao Wei Guo Bo You Fei Song Tao Yao Ziyun Wang Prof. Bao Yu Xia School of Chemistry and Chemical Engineering State Key Laboratory of Materials Processing and Die & Mould Technology Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service Failure Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology (HUST) 1037 Luoyu Rd Wuhan 430074 China School of Chemical Sciences University of Auckland Auckland 1010 New Zealand National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 P. R. China CAS Key Laboratory of Materials for Energy Conversion Shanghai Institute of Ceramics Chinese Academy of Sciences (SICCAS) Shanghai 200050 China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201800 China

Revealing the dynamic reconstruction process and tailoring advanced copper (Cu) catalysts is of paramount significance for promoting the conversion of CO 2 into ethylene (C 2 H 4 ), paving the way for carbon neutralization and facilitating renewable energy storage. In this study, we initially employed density functional theory (DFT) and molecular dynamics (MD) simulations to elucidate the restructuring behavior of a catalyst under electrochemical conditions and delineated its restructuring patterns. Leveraging insights into this restructuring behavior, we devised an efficient, low-coordination copper-based catalyst. The resulting synthesized catalyst demonstrated an impressive Faradaic efficiency (FE) exceeding 70 % for ethylene generation at a current density of 800 mA cm −2 . Furthermore, it showed robust stability, maintaining consistent performance for 230 hours at a cell voltage of 3.5 V in a full-cell system. Our research not only deepens the understanding of the active sites involved in designing efficient carbon dioxide reduction reaction (CO 2 RR) catalysts but also advances CO 2 electrolysis technologies for industrial application.

关键词： Carbon dioxide reduction Restructuring behavior Cu catalyst Ethylene Low coordination number

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Fibrous nanosilica spheres modified by TEPA as highly efficient adsorbents for CO2 capture from air and flue gas

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Separation and Purification technology 2025年 373卷

作者： Xiao, Li Jia, Xiaohao Yu, Zhikun Guo, Zonghui Ming, Hongfang Jiang, Mengyao Guo, Penghui Wang, Fengfeng Rezaei, Fateme Fan, Yanfang CNOOC Key Laboratory of Liquefied Natural Gas and Low-Carbon Technology China National Offshore Oil Corporation Beijing100028 China State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and Environment China University of Petroleum-Beijing Beijing102249 China College of Carbon Neutrality Future Technology China University of Petroleum-Beijing Beijing102249 China Department of Chemical Environmental and Materials Engineering University of Miami MiamiFL33124 United States

The increasing atmospheric CO2, majorly contributed by fossil fuel consumption and industrial activities, is a critical global issue. Amine-functionalized adsorbents are considered as a type of promising materials for post combustion CO2 capture and direct air capture. However, conventional adsorbents often face significantly reduced CO2 capacities and diffusion limitations due to restricted pore structures when CO2 concentration reduces to 400 ppm. In this study, TEPA-functionalized fibrous nanosilica (FNS-TEPA) with hierarchical fibrous opening pore structure was synthesized and evaluated for CO2 adsorption at different CO2 concentrations and adsorption temperatures. The adsorption capacity increased with TEPA loading, reaching 2.2 mmol/g at 50 wt% TEPA in 400 ppm CO2/N2 at 35 °C. The noteworthy performance is nearly equivalent CO2 adsorption capacity when exposed to 400 ppm and 10 % CO2, when TEPA loading is above 40 wt%. Under sub-ambient conditions, FNS-TEPA40 exhibited a capacity of 0.92 mmol/g, increasing with elevated temperatures from −20 °C to 30 °C. Under humid conditions, the CO2 adsorption capacity further increased to 2.9 mmol/g in 10 % CO2/N2 and 3.3 mmol/g in 400 ppm CO2/N2, respectively. Avrami model analysis effectively described the adsorption kinetics, revealing a valley-shaped trend in the adsorption rate constants. The unique pore structure of FNS improved TEPA dispersion and active site accessibility, enabling its faster adsorption rates even at a 50 wt% amine loading. Notably, the distinctive fibrous pore structure of FNS produced a nearly rectangular CO2 adsorption isotherm, enabling FNS-TEPA to maintain stable adsorption behavior across different CO2 concentrations. In summary, FNS-TEPA exhibited high CO2 capacity within both air and flue gas, rapid adsorption kinetics, and good thermal stability, making it highly promising for applications in DAC and post-combustion CO2 capture. © 2025 Elsevier B.V.

关键词： Gas adsorption

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Hole-Mediated Lattice Oxygen Redox Design for Perovskite Oxide Catalysts

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Angewandte Chemie 2025年

作者： Dr. Xinbo Li Dr. Xiyang Wang Dr. Yaowen Wang Dr. Jingze Shao Prof. Yimin A. Wu Dr. Subhajit Jana Prof. Haozhe Liu Prof. Yue Peng Dr. Zhiyao Wu Dr. Zhen Li Dr. Yingge Cong Prof. Yawen Zhang Prof. Guangshe Li Prof. Liping Li State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changchun 130012 China Department of Mechanical and Mechatronics Engineering Waterloo Institute for Nanotechnology Materials Interface Foundry University of Waterloo Waterloo Ontario N2 L 3G1 Canada Center for High Pressure Science and Technology Advanced Research Beijing 100094 China State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi University Nanning 530004 China CAS Key Laboratory of Bio Medical Diagnostics Suzhou Institute of Biomedical Engineering and Technology Chinese Academy of Sciences Suzhou 215163 China Beijing National Laboratory for Molecular Sciences (BNLMS) State Key Laboratory of Rare Earth Materials Chemistry and Applications PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Present design and application of perovskite oxide catalysts assume lattice oxygen redox (LOR) mechanisms that depend on lattice oxygen activity without consideration of the entire redox cycle. Herein, using in situ characterizations and theoretical calculations, we uncover a hole-mediated LOR cycle on p-type Sr-deficient SrFeO 3–δ (SFO-Srv) perovskites in CO oxidation reaction. Sr vacancies activate surface lattice oxygen of SFO-Srv and promote formation of highly covalent Fe (4–x)+ -O (2–x)– sites. In situ electrical conductivity measurement demonstrates that holes directly participate in the entire LOR cycle, and are reversibly consumed and regenerated in reducing/oxidizing atmosphere via Fe (4–x)+ -O (2–x)– sites of SFO-Srv. Hole-mediated LOR in SFO-Srv, as revealed by in situ soft X-ray absorption spectroscopy, occurs through changing in covalency of Fe−O bonds, O 2p hole state, and electron density of Fe sites. 18 O 2 labeling experiment further confirms an improved Mars–van Krevelen pathway in the hole-mediated LOR cycle, which accounts for a ten-times enhancement of SFO-Srv for CO reaction rate over that of SFO alone.

关键词： p-type perovskite oxides Sr vacancy lattice oxygen redox reaction mechanism SrFeO3

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Corrosion Behavior of Inconel 625 Alloy in Na2SO4–K2SO4 at High Temperature 1

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Chinese materials Conference, CMC 2018

作者： Ma, Yuan-Jun Ding, Yutian Liu, Jian-Jun Gao, Yu-Bi Zhang, Dong State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of Technology Lanzhou730050 China State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization Jinchuan Group Co. Ltd. Jinchang737100 China

ISBN: (数字)9789811359446

ISBN: (纸本)9789811359439

The corrosion behavior of Inconel 625 alloy at 800 and 900 °C in the molten salt of 75 wt% Na2SO4–25 wt% K2SO4 was studied. The corrosion mechanism of Inconel 625 alloy after hot corrosion is mainly alkaline melting mechanism. The Cr2O3 on the surface of the alloy dissolved in molten salt as Na2CrO4, leading to the loss of the protective oxide layer on the alloy surface. With the decomposition of Cr2O3 on the surface of the alloy, Cr-depleted region appeared at the interface of the alloy matrix/corrosion layer, which inhibited the growth of the Cr2O3 oxide layer and resulted in the discontinuous oxide layer. This caused O and S to invade the substrate and corrode the alloy matrix. When the alloy was corroded at 800 °C for 120 h, the corrosion rate was about 3 mg/cm2. The corrosion layer was relatively complete, and it mainly consisted of flaky Cr2O3 and spinel-like NiCr2O4. When the alloy was corroded at 900 °C for 120 h, the corrosion rate was about 6 mg/cm2, and obvious shedding and faults appeared in the corrosion layer, which were mainly divided into three layers: the outer layer was composed of NiCr2O4 and NiO;the middle layer was a dense Cr2O3;the inner layer was composed of sulfides (Cr2S3 and Ni3S2), oxides (Cr2O3 and NiO), telluride, etc. Through thermodynamic calculation and analysis, it was found that SO2 decomposed from molten salt under high temperature could cause severe corrosion to the alloy. The main corrosion products were Cr2O3, Cr2S3, NiO, and Ni3S2. © 2019, Springer Nature Singapore Pte Ltd.

关键词： Sulfur compounds

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Research on low-temperature glass sealing of 50%Si/Al shell

Research on low-temperature glass sealing of 50%Si/Al shell

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International Conference on (ICEPT) Electronic Packaging technology

作者： Xinfeng Hao Jitai Niu Bo Xu Zhenjiang Wang Quality Department Nanjing Research Institute of Electronics Technology Nanjing China State key laboratory of advanced welding and joining Harbin Institute of Technology Herbin China China Building Material Academy Key Laboratory of Special Glass Preparation and Processing of Building Materials Industry Beijing China School of Materials Science and Engineering Henan Polytechnic University Jiaozuo China

ISBN: (数字)9781728168265

ISBN: (纸本)9781728168272

In view of the problems in the brazing process of the Radio frequency (RF) microwave channel in Si/Al packaging shell, the technical requirement of low-temperature glass sealing of Si/Al packaging shell was analyzed. The feasibility of the glass material with low sealing temperature, low expansion coefficient and low dielectric property was proved by theory and experiment. The single glass material could not meet the requirement of low temperature sealing and radio frequency transmission. Therefore, the composite glass insulator of DM305 high-temperature glass column with low-temperature glass ring wrapped was designed. The low sealing temperature, low expansion coefficient and low dielectric constant can be obtained by this composite structure. The sealing structure is compatible with the plating and packaging process of 50%Si/Al Shell, which is suitable for engineering application.

关键词： Glass Packaging Radio frequency Temperature Reliability Metals Conductors

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Unprecedented and highly stable lithium storage capacity of (001) faceted nanosheet-constructed hierarchically porous TiO2/rGO hybrid architecture for high-performance Li-ion batteries

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National science review 2020年第6期7卷 1046-1058页

作者： Wen-Bei Yu Zhi-Yi Hu Jun Jin Min Yi Min Yan Yu Li Hong-En Wang Huan-Xin Gao Li-Qiang Mai Tawfique Hasan Bai-Xiang Xu Dong-Liang Peng Gustaaf Van Tendeloo Bao-Lian Su State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China. Institute of Materials Science Technische Universität Darmstadt Darmstadt 64287 Germany. Fundamental Research Department SINOPEC Shanghai Research Institute of Petrochemical Technology Shanghai 201208 China. Cambridge Graphene Centre University of Cambridge Cambridge CB3 0FA UK. Department of Materials Science and Engineering College of Materials Xiamen University Xiamen 361005 China. Nanostructure Research Centre Wuhan University of Technology Wuhan 430070 China.

Active crystal facets can generate special properties for various applications. Herein, we report a (001) faceted nanosheet-constructed hierarchically porous TiO/rGO hybrid architecture with unprecedented and highly stable lithium storage performance. Density functional theory calculations show that the (001) faceted TiO nanosheets enable enhanced reaction kinetics by reinforcing their contact with the electrolyte and shortening the path length of Li diffusion and insertion-extraction. The reduced graphene oxide (rGO) nanosheets in this TiO/rGO hybrid largely improve charge transport, while the porous hierarchy at different length scales favors continuous electrolyte permeation and accommodates volume change. This hierarchically porous TiO/rGO hybrid anode material demonstrates an excellent reversible capacity of 250 mAh g at 1 C (1 C = 335 mA g) at a voltage window of 1.0-3.0 V. Even after 1000 cycles at 5 C and 500 cycles at 10 C, the anode retains exceptional and stable capacities of 176 and 160 mAh g, respectively. Moreover, the formed LiTiO nanodots facilitate reversed Li insertion-extraction during the cycling process. The above results indicate the best performance of TiO-based materials as anodes for lithium-ion batteries reported in the literature.

关键词： (001) faceted TiO2 nanosheets Li2Ti2O4 crystallites porous hierarchy reduced graphene oxide unprecedented lithium storage capacity

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Correction: Synergistic Effects of Pre-charged Hydrogen and Tensile Stress on the Stress Corrosion Cracking of 2024-T351 Aluminum Alloy

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JOM 2024年第2期77卷 969-969页

作者： He, Qiyao Liang, Yuexing Chen, Junzhou Wang, Xiaoya Shao, Wenzhu Jiang, Jiantang Zhen, Liang School of Materials Science and Engineering Harbin Institute of Technology Harbin China Oil and Gas Engineering Research Institute PetroChina Tarim Oilfield Company Korla China Beijing Institute of Aeronautical Materials Beijing China Beijing Engineering Research Center of Advanced Aluminum Alloys and Application Beijing China Institute of Special Environments Physical Sciences Harbin Institute of Technology (Shenzhen) Shenzhen China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of Technology Harbin China

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Hemocompatibility of Mg-Zn-Y-Nd: Fabrication of Citric Acid/RGD Multilayers on Mg-Zn-Y-Nd Alloy via Layer-by-Layer Self-Assembly for Promoting Surface Biocompatibility (Adv. Mater. Interfaces 13/2021)

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advanced materials Interfaces 2021年第13期8卷

作者： Fang Kou Changsheng Liu Liguo Wang Aqeela Yasin Jingan Li Shaokang Guan School of Materials Science and Engineering and Henan Key Laboratory of Advanced Magnesium Alloy and Key Laboratory of Materials Processing and Mold Technology (Ministry of Education) Zhengzhou University Zhengzhou 450001 China

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Sabatier Relations in Electrocatalysts Based on High-entropy Alloys with Wide-distributed d-band Centers for Li-O2Batteries

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Angewandte Chemie 2023年第44期135卷

作者： Jiaming Tian Yuan Rao Wenhui Shi Jiawei Yang Wenjie Ning Haoyu Li Yonggang Yao Haoshen Zhou Shaohua Guo College of Engineering and Applied Sciences Jiangsu Key Laboratory of Artificial Functional Materials National Laboratory of Solid State Microstructures Collaborative Innovation Centre of Advanced Microstructures Frontiers Science Center for Critical Earth Material Cycling Nanjing University Nanjing 210093 P. R. China Lab of Power and Energy Storage Batteries Shenzhen Research Institute of Nanjing University Shenzhen 518057 P. R. China State Key Laboratory of Materials Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Li-O 2 battery (LOB) is a promising “beyond Li-ion” technology with ultrahigh theoretical energy density (3457 Wh kg −1 ), while currently impeded by the sluggish cathodic kinetics of the reversible gas-solid reaction between O 2 and Li 2 O 2 . Despite many catalysts are developed for accelerating the conversion process, the lack of design guidance for achieving high performance makes catalysts exploring aleatory. The Sabatier principle is an acknowledged theory connecting the scaling relationship with heterogeneous catalytic activity, providing a tradeoff strategy for the topmost performance. Herein, a series of catalysts with wide-distributed d-band centers (i.e., wide range of adsorption strength) are elaborately constructed via high-entropy strategy, enabling an in-depth study of the Sabatier relations in electrocatalysts for LOBs. A volcano-type correlation of d-band center and catalytic activity emerges. Both theoretical and experimental results indicate that a moderate d-band center with appropriate adsorption strength propels the catalysts up to the top. As a demonstration of concept, the LOB using FeCoNiMnPtIr as catalyst provides an exceptional energy conversion efficiency of over 80 %, and works steadily for 2000 h with a high fixed specific capacity of 4000 mAh g −1 . This work certifies the applicability of Sabatier principle as a guidance for designing advanced heterogeneous catalysts assembled in LOBs.

关键词： High Entropy Li-O2 Batteries Oxygen Conversion Sabatier Principle d-Band Center

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