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Metallurgical performance evaluation of space-weathered Chang’e-5 lunar soil

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1241-1248页

作者： Chen Li Wenhui Ma Yang Li Kuixian Wei Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Faculty of Metallurgical and Energy engineering Kunming University of Science and TechnologyKunming 650093China

Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical *** involves systematic and theoretical engineering technology for utilizing planetary resources in ***,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the *** this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil *** microstructural characteristics of the lunar soil may drastically change its metallurgical *** main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral *** nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar *** ions injected by solar wind may promote the hydrogen reduction *** widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar ***,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar *** is a property that earth samples and tradi-tional simulated lunar soil *** application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.

关键词： space metallurgy Chang’e-5 lunar soil space weathering metallurgical performance

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CFD-DEM analysis of particle polydispersity on the performance of fluidised bed reactor during silane pyrolysis Author links open overlay panel

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Particuology 2024年第8期91卷 72-87页

作者： Akshayveer Vijay M.Shinde MS2Discovery Interdisciplinary Research institute Wilfrid Laurier UniversityWaterlooOntarioN2L3C5Canada Department of Chemical engineering Indian Institute of Technology(BHU)Varanasi221005India

A CFD-DEM model is developed for chemical vapour deposition of silane in a fluidized bed reactor to investigate the effect of polydispersity on local phase dynamics,mass and heat transport,as well as the rate of Si *** gas-phase fines formation and heterogeneous deposition on the seed particle,as well as the scavenging effect for Si particle growth,are *** method is first validated against the experimentally measured Si deposition rate,percentage of fine production and minimum fluidisation ***,the properties,primarily particle intermixing,fluidisation behaviour and bubble dynamics along with the deposition process,are analyzed for several polydisperse beds under various operating *** effect of polydispersity of the bed on a fraction of the bubble size,dense phase expansion and interchange coefficient between various phases is thoroughly investigated to establish a correlation with reactor *** results show that broad-Gaussian particle size distribution(PSD)exhibits excellent improvement in fluidisation behaviour,resulting in a high deposition rate,and minimum formation of Si fines.

关键词： CFD-DEM method Chemical vapour deposition(CVD) particle size distribution Silicon Gas-solid fluidized bed

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Coordination of distinctive pesticide adjuvants and atomization nozzles on droplet spectrum evolution for spatial drift reduction

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Chinese Journal of Chemical engineering 2024年第2期66卷 250-262页

作者： Shidong Xue Jingkun Han Xi Xi Zhong Lan Rongfu Wen Xuehu Ma State Key Laboratory of Fine Chemicals Liaoning Key Laboratory of Clean Utilization of Chemical ResourcesInstitute of Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 16024China School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong 999077China China Tianchen engineering Corporation Tianjin 300400China School of Energy and Power engineering Dalian University of TechnologyDalian 116024China

Pesticide adjuvants,as crop protection products,have been widely used to reduce drift loss and improve utilization efficiency by regulating droplet ***,the coordinated regulation mechanisms of adjuvants and nozzles on droplet spectrum remain ***,we established the relationship between droplet spectrum evolution and liquid atomization by investigating the typical characteristics of droplet diameter distribution near the *** on this,the regulation mechanisms of distinctive pesticide adjuvants on droplet spectrum were clarified,and the corresponding drift reduction performances were quantitively evaluated by wind tunnel *** shows that the droplet diameter firstly shifts to the smaller due to the liquid sheet breakup and then prefers to increase caused by droplet *** the surface tension of sprayed liquid facilitates the uniform liquid breakup and increasing the viscosity inhibits the liquid deformation,which prolong the atomization process and effectively improve the droplet *** a result,the drift losses of flat-fan and hollow cone nozzles are reduced by about 50%after adding organosilicon and vegetable oil *** contrast,the air induction nozzle shows a superior anti-drift ability,regardless of distinctive *** findings provide insights into rational adjuvant design and nozzle selection in the field application.

关键词： Pesticide drift Spray droplets particle size distribution Spray atomization Transport processes Adjuvants

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Water-induced physicochemical and pore changes in limestone for surrounding rock across pressure aquifers

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Journal of Mountain Science 2024年第09期 3186-3200页

作者： WU Daguo PENG Jianhe XIA Zhenzhao School of Civil and Hydraulic engineering Hefei University of Technology Anhui and Huaihe River institute of Hydraulic Research School of Civil and Hydraulic engineering Huazhong University of Science and Technology

Osmotic water alters the physicochemical properties and internal structures of limestone. This issue is particularly critical in tunnel construction across mountainous regions with aquifers, where pressurized groundwater can destabilize the limestone-based surrounding rock. Thus, systematic research into the physicochemical properties and pore structure changes in the limestone under pressurized water is essential. Additionally, it is essential to develop an interpretable mathematical model to accurately depict how pressurized osmotic water weakens limestone. In this research, a specialized device was designed to simulate the process of osmotic laminar flow within limestone. Then, four main tests were conducted: mass loss, acoustic emission(AE), mercury intrusion porosimetry(MIP), and fluorescence analysis. Experimental results gained from tests led to the development of a “particle-pore throat-water film” model. Proposed model explains water-induced physicochemical and pore changes in limestone under osmotic pressure and reveals evolutionary mechanisms as pressure increases. Based on experimental results and model, we found that osmotic pressure not only alters limestone composition but also affects pore throats larger than 0.1 μm. Furthermore, osmotic pressure expands pore throats, enhancing pore structure uniformity, interconnectivity, and permeability. These effects are observed at a threshold of 7.5 MPa, where cohesive forces within the mineral lattice are surpassed, leading to the breakdown of erosion-resistant layer and a significant increase in hydrochemical erosion.

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Shear wave velocity model using HVSR inversion beneath Bandar Lampung City

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Earthquake Science 2024年第4期37卷 337-351页

作者： Ahmad Zaenudin Alhada Farduwin Gede I Boy Darmawan Karyanto Department of Geophysical engineering University of LampungBandar Lampung 35145Indonesia Department of Geophysical engineering Sumatera Institute of TechnologySouth Lampung 35365Indonesia

The horizontal-to-vertical spectral ratio(HVSR)method has been used to characterize site-effect parameters that are indispensable in seismic hazard and risk-reduction studies in urban areas and rapid land-use *** method is widely used because it is the cheapest and simplest geophysical method for the acquisition and processing *** subsequent developments,the HVSR method has been widely used to determine elastic rock parameters,particularly shear wave velocity(v_(S)),through the HVSR curve inversion ***,the v_(S)structural model can be used to delineate the presence of complex geological structures,particularly faults and sedimentary *** Lampung is a city in Lampung Province with many fault structures and groundwater basins to the *** are 83 HVSR measurement points around Bandar Lampung for delineating the presence of fault structures and groundwater *** produced the HVSR curve from the measurement results and then performed an inversion process using the particle swarm optimization algorithm to obtain v_(S)for the depth ***,from this profile,we produced a two-dimensional(2D)lateral and vertical *** mean v_(S)value was calculated from all the measurement points,and we found stiff soil layers reaching depths of approximately 5 m,with a value of v_(S)<330 m/s.A bedrock layer with a velocity exceeding 1250 m/s was visible at a depth of 100 *** on the 2D model,the v_(S)structure shows that the city of Bandar Lampung is divided into two zones,with a NW-SE *** north-middle-eastern part of the city consists of harder *** harder rock is characterized by extremely high v_(S)values,starting from a depth of 50 *** contrast,the south-middle-west exhibits a low-moderate v_(S)anomaly associated with groundwater basins SW of the *** the 2D v_(S)structural model,fault structures can be found along the city,characterized by a contrast of v_(S)values from low to medium and from me

关键词： shear wave velocity HVSR fault structures groundwater basin Bandar Lampung City

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Utilization of Basalt Saw Mud as a Spherical Porous Functional Aggregate for the Preparation of Ordinary Structure Concrete

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Journal of Wuhan University of technology(Materials Science) 2024年第2期39卷 364-375页

作者：周永祥关青锋 LENG Faguang WANG Jing LI Tianjun Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China Key Laboratory of Urban Security and Disaster engineering of Ministry of Education Beijing University of TechnologyBeijing 100012China School of Materials Science and engineering Southeast UniversityNanjing 211189China institute of Building Materials China Academy of Building ResearchBeijing 100013China State Key Laboratory of Building Safety and Built Environment Beijing 100013China Zhejiang Chinavigor E.P.technology Co. Ltd.Zhejiang 315043China

To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural *** our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and *** effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were *** experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 *** W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs *** the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of *** exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.

关键词： lightweight concrete civil concrete building basalt saw mud fly ash internal curing environmentally friendly

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CFD-DEM simulation of fluorination reaction in fluidized beds with local grid and time refinement method

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Particuology 2024年第1期84卷 145-157页

作者： Mofan Qiu Lin Jiang Rongzhen Liu Yaping Tang Malin Liu institute of Nuclear and New Energy technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing100084China

The gas-solid reaction process with wide particle size distribution is extensively used in the chemical engineering field,especially the particle reacts with the gas gradually,such as fluorination reactions in fluidized *** the computational fluid dynamics-discrete element method(CFD-DEM)is used for the coupling simulation of multiphase and polydisperse particle reaction system,the grid size directly affects the accuracy of flow field information and simulation of chemical ***,particle calculation time step will directly affect the efficiency of coupling *** this work,a local grid and time step refinement method is proposed to simulate multiphase and polydisperse particle fluid-ization reaction *** this method,the refined DEM grids are automatically generated in the computational domain around the fine particles,and the detailed fluid phase information is obtained with the interpolation *** the two-phase coupling process,particles are divided into different groups based on physical properties,each group has its own independent time *** multistage conical-cylindrical spouted bed is proposed for the fluorination reaction process;the operating gas ve-locity range of the polydisperse particle system is extended by the new design while the particle size distribution changes with the gas-solid reaction *** is demonstrated that the local grid and time step refinement method can improve the accuracy and efficiency of the traditional CFD-DEM method in the reaction process simulation,which describes a polydisperse particle system with wide particle size *** at improving the simulation accuracy and efficiency,this paper will be helpful for simulating the particle reaction process in the gas-solid fluidized bed and beneficial for the development of the CFD-DEM method.

关键词： CFD-DEM Polydisperse particle Two-phase flow Fluidized bed

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Production of composites with high relative permittivity using the spouted bed technique

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Particuology 2019年第1期17卷 184-189页

作者： E. Eichner P.-K. Fischer S. Heinrich GA Schneider institute of solids process engineering and particle technology Denickestr1521073 HamburgGermany institute of Advanced Ceramics Hamburg University of TechnologyDenickestr1521073 HamburgGermany

This contribution presents a new application of the spouted bed technique. The developed production process involves coating fine copper particles with a polymer in a spouted bed plant and then hot pressing the produced granules to form a compact consisting of a copper–polymer composite with a high filling degree. The fabricated composites possess high relative permittivity, which is advantageous for the production of effective capacitors. With increasing filling degree of copper, the relative permittivity of the composites increased, with a maximum relative permittivity of 214 obtained for the composite containing 78.1 vol% copper. Such a high filling degree can be achieved with conductive particles without obtaining a conductive composite by using the spouted bed technology in the production process. The high relative permittivity results from the high filling degree of particles isolated by a polymer coating.

关键词： Spouted bed High relative permittivity Fine particles Coating Metal-polymer composite

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Modeling and prediction of tribological properties of copper/aluminum-graphite self-lubricating composites using machine learning algorithms

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Friction 2024年第6期12卷 1322-1340页

作者： Huifeng NING Faqiang CHEN Yunfeng SU Hongbin LI Hengzhong FAN Junjie SONG Yongsheng ZHANG Litian HU School of Electrical and Mechanical engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China

The tribological properties of self-lubricating composites are influenced by many variables and complex ***-driven methods,including machine learning(ML)algorithms,can yield a better comprehensive understanding of complex problems under the influence of multiple parameters,typically for how tribological performances and material properties *** of friction coefficients and wear rates of copper/aluminum-graphite(Cu/Al-graphite)self-lubricating composites with their inherent material properties(composition,lubricant content,particle size,processing process,and interfacial bonding strength)and the variables related to the testing method(normal load,sliding speed,and sliding distance)were analyzed using traditional approaches,followed by modeling and prediction of tribological properties through five different ML algorithms,namely support vector machine(SVM),K-Nearest neighbor(KNN),random forest(RF),eXtreme gradient boosting(XGBoost),and least-squares boosting(LSBoost),based on the tribology experimental *** demonstrated that ML models could satisfactorily predict friction coefficient and wear rate from the material properties and testing method variables ***,the LSBoost model based on the integrated learning algorithm presented the best prediction performance for friction coefficients and wear rates,with R^(2) of 0.9219 and 0.9243,*** importance analysis also revealed that the content of graphite and the hardness of the matrix have the greatest influence on the friction coefficients,and the normal load,the content of graphite,and the hardness of the matrix influence the wear rates the most.

关键词： self-lubricating composites machine learning(ML) tribological properties prediction

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Dynamic simulation insights into friction weakening effect on rapid long-runout landslides:A case study of the Yigong landslide in the Tibetan Plateau,China

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China Geology 2024年第2期7卷 222-236页

作者： Zi-zheng Guo Xin-yong Zhou Da Huang Shi-jie Zhai Bi-xia Tian Guang-ming Li School of Civil and Transportation engineering Hebei University of TechnologyTianjin 300401China School of Geological engineering and Geomatics Chang’an UniversityXi’an 710054China Tianjin Municipal engineering Design&Research institute(TMEDI) Tianjin 300392China

This study proposed a novel friction law dependent on velocity,displacement and normal stress for kinematic analysis of runout process of rapid *** well-known Yigong landslide occurring in the Tibetan Plateau of China was employed as the case,and the derived dynamic friction formula was included into the numerical simulation based on particle Flow *** showed that the friction decreased quickly from 0.64(the peak)to 0.1(the stead value)during the 5s-period after the sliding initiation,which explained the behavior of rapid movement of the *** monitored balls set at different sections of the mass showed similar variation characteritics regarding the velocity,namely evident increase at the initial phase of the movement,followed by a fluctuation phase and then a stopping *** peak velocity was more than 100 m/s and most particles had low velocities at 300s after the landslide *** spreading distance of the landslide was calculated at the two-dimension(profile)and three-dimension scale,*** with the simulation result without considering friction weakening effect,our results indicated a max distance of about 10 km from the initial unstable position,which fit better with the actual situation.

关键词： Rapid long-runout landslide PFC Friction weakening Three-dimension Numerical simulation Tibetan Plateau Hydrogeology engineering Geological hazards survey engineering

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