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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 301-314页

作者： Zhanghao Wan Shiliang Yang Desong Kong Dongbo Li Jianhang Hu Hua Wang State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Southwest Copper branch Yunnan Copper Co.Ltd.Kunming 650102China

The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace were explored by means of the computational fluid dynamics *** essential aspects of the fluid phase(e.g.,splashing volume,dead zone of copper slag,and gas penetration depth)were explored together with the effect of sinusoidal pulsating gas intake on the momentum-transfer performance between *** results illustrated that two relatively larger vortices and two smaller vortices appear in the bubble waist and below the lance,*** expansion of larger ones as well as the shrinking of smaller ones combine to cause the contraction of the bubble *** to the results of the case with a fixed gas injection velocity(V_(g)=58 m/s),the splashing volume and dead zone volume of the slag under the V_(g)=58+10sin(2πt)condition are reduced by 24.9%and 23.5%,respectively,where t represents the instant *** penetration depth and slag motion velocity of the latter are 1.03 and 1.31 times high-er than those of the former,respectively.

关键词： top-blown smelting furnace pulsed flow volume of fluid penetration depth splashing volume

Influence of cerium and yttrium addition on strength and electrical conductivity of pure aluminum alloys

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Journal of Rare Earths 2024年第3期42卷 600-611,I0006页

作者： Guojian Lin Lu Li Zhengwei Guo Xianjun Jia Xiao Wang Zhentao Yuan Guoxing Zhang Yun Zhan Quan Shan Zulai Li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Research Center for Analysis and Measurement Kunming University of Science and TechnologyKunming650093China City College Kunming University of Science and TechnologyKunming650051China

To develop pure aluminum alloys with high conductivity and strength, Al-0.2Ce and Al-0.2Ce-0.1Y alloys were prepared by rolling and annealing processes in this study. The effects of trace rare earth elements on the strength and electrical conductivity of the pure aluminum alloys were investigated. It is revealed that the addition of Ce and Y to pure aluminum can effectively enhance the strength and electrical conductivity of the alloys. In Al-0.2Ce, the addition of Ce can effectively refine the grain size of a-Al, with an average grain size of 90.68 μm in the as-cast state. The grain size of the alloy is further reduced to 87.55 μm by the simultaneous addition of Y. The synergistic addition of Ce and Y changes the properties of the alloy. The addition of Ce and Y also produces the Al_(11)Ce_(3) and Al_(3)Y second phases, which have coherent relationship with a-Al. The two-dimensional mismatch degree was calculated to be only 4.43%and 0.85%, respectively, which can provide a certain amount of nucleation substrate for a-Al in the incubation stage. The interfacial match between the L1_(2)structure of Al_(3)Y and a-Al was calculated using first-principles simulations. The results indicate that Al_(3)Y has a strong bonding effect with a-Al. Nanoscale second phases at grain boundaries can be effective in reducing resistivity due to dislocation *** second phases with better matching interfaces to the substrate have no positive effect on the scattering motion of electrons.

关键词： Pure aluminum Rare earths Impurity purification First-principles calculations Strength-conductivity contradiction

Recovery of scandium from silicate minerals by high-pressure leaching in sulfuric acid

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Journal of Rare Earths 2024年第7期42卷 1375-1384,I0007页

作者： Peng Yan Xiaoming Chen Likun Gao Bo Yang Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming650093China Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming650093China School of Chemistry and Chemical Engineering Kunming UniversityKunming650214China

This study investigated the leaching of scandium from a Sc-bearing silicate *** Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%*** main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of ***-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this *** Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 *** X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole *** with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.

关键词： Silicate minerals Scandium High-pressure Leaching Concentrated sulfuric acid Rare earths

Modification of LiMn_(0.6)Fe_(0.4)PO_(4)lithium-ion battery cathode materials with a fluorine-doped carbon coating

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Particuology 2024年第9期92卷 278-287页

作者： Debao Pan Ziyuan Liu Chengping Li Rundong Wan Jinsong Wang Jiangzhao Chen Ding Wang Jinkun Liu Yingjie Zhang Jianhong Yi Rui Bao Zhengfu Zhang Peng Dong Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China

In this study,glucose and NH4F were utilized as sources of carbon and fluorine,respectively,for the synthesis of LiMn_(0.6)Fe_(0.4)PO_(4)(LMFP)*** nanoscales were subsequently modified with varying levels of fluorine-doped carbon through co-precipitation and mechanical ball milling *** LMFP,incorporating carbon and varying levels of fluoride ions,exhibit higher specific discharge capacities at 0.2 Cand electrochemical characteristics compared to the original LMFP coated solely with *** inclusion of fluorine-doped carbon in the composite material creates numerous pathways for expeditious electron ***,the partial formation of metal fluoride at the interface between the surface of LMFP and the layer of carbon coating doped with fluorine enhances the reduction in the charge-transfer *** modified ferromanganese phosphate cathode material reveals an outstanding discharge capacity displaying a reversible discharge specific capacity value of 131.73 mA h g^(−1)at 10C and 154.6 mA h g^(−1)at 0.2C,due to its unique structure.

关键词： Lithium manganese iron phosphate Anode Electrochemical Fluorine-doped carbon

Symmetric Brownian motor subjected to Lévy noise

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Chinese Physics B 2024年第2期33卷 222-227页

作者：贾考胡兰聂林如 Faculty of Science Kunming University of Science and TechnologyKunming 650500China

In the past few years,attention has mainly been focused on the symmetric Brownian motor(BM)with Gaussian noises,whose current and energy conversion efficiency are very ***,we investigate the operating performance of the symmetric BM subjected to Lévy *** numerical simulations,it is found that the operating performance of the motor can be greatly improved in asymmetric Lévy *** any load,the Lévy noises with smaller stable indexes can let the motor give rise to a much greater *** a load,the energy conversion efficiency of the motor can be enhanced by adjusting the stable indexes of the Lévy noises with symmetry *** results of this research are of great significance for opening up BM’s intrinsic physical mechanism and promoting the development of nanotechnology.

关键词： symmetric Brownian motor average velocity energy conversion efficiency Lévy noise

Stabilization/solidification mechanisms of tin tailings and fuming slag-based geopolymers for different heavy metals

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 43-55页

作者： Xian Zhou Zhengfu Zhang Hui Yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China kunming Metallurgical Research Institute Co. Ltd.Kunming650031China

Tin mine tailings(TMT)and fuming slag(FS)contain many heavy metals(As,Cr,Cu,Zn and Mn)that cause severe pollution to the ***,geopolymers were prepared using TMT,FS and flue gas desulfurization gypsum(FGDG)to immobilize heavy metals,and their compressive strength and heavy metal leaching toxicity were *** was first determined that T4F5(TMT:FS=4:5)sample exhibited the highest compressive strength(7.83 MPa).T4F5 achieved 95%immobilization efficiency for As and Cr,and nearly 100%for Cu,Zn and Mn,showing good immobilization performance.A series of characterization analyses showed that heavy metal cations can balance the charge in the geopolymer and replace Al in the geopolymer structure to form covalent *** addition,about 2%–20%of heavy metal Fe was immobilized in hydration products,heavy metal hydroxides and non-bridging Si–O and Al–O coordination with silica-aluminate ***_(3)^(3−) was oxidized into AsO_(4)^(3−),which may form Ca–As or Fe–As ***_(2)O_(7)^(2−)was converted to CrO_(4)^(2−)under alkaline environment and then combined with OH−to form Cr(OH)3 ***^(2+)may react directly with dissolved silicate to form Mn_(2)SiO_(4) and also form Mn(OH)_(2) *** unstable Mn(OH)_(2) can be further oxidized to MnO_(2).The heavy metal cations were immobilized in the silicoaluminate lattice,while the anions tended to form insoluble *** results may benefit the industry and government for better handling of TMT,FS and solid wastes containing the abovementioned five heavy metals.

关键词： Heavy metals Cementitious materials Tin tailings Stabilization/solidification Redox

Semantic-aware entity alignment for low resource language knowledge graph

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Frontiers of Computer Science 2024年第4期18卷 97-106页

作者： Junfei TANG Ran SONG Yuxin HUANG Shengxiang GAO Zhengtao YU Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China Yunnan Key Laboratory of Artificial Intelligence Kunming University of Science and TechnologyKunming 650500China

Entity alignment(EA)is an important technique aiming to find the same real entity between two different source knowledge graphs(KGs).Current methods typically learn the embedding of entities for EA from the structure of KGs for *** EA models are designed for rich-resource languages,requiring sufficient resources such as a parallel corpus and pre-trained language ***,low-resource language KGs have received less attention,and current models demonstrate poor performance on those low-resource ***,researchers have fused relation information and attributes for entity representations to enhance the entity alignment performance,but the relation semantics are often *** address these issues,we propose a novel Semantic-aware Graph Neural Network(SGNN)for entity ***,we generate pseudo sentences according to the relation triples and produce representations using pre-trained ***,our approach explores semantic information from the connected relations by a graph neural *** model captures expanded feature information from *** results using three low-resource languages demonstrate that our proposed SGNN approach out performs better than state-of-the-art alignment methods on three proposed datasets and three public datasets.

关键词： graph neural network knowledge graph entity alignment low-resource language

In situ anchoring in carbon matrix of Bi_(2)O_(2)CO_(3) as a high-performance anode material for Li-ion batteries

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Rare Metals 2024年第8期43卷 3634-3646页

作者： Pu-Qiang He Jun Guo Hui Huang Zhong-Cheng Guo Faculty of Metallurgy and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Research Center of Metallurgical Electrode Materials Engineering Technology Kunming 650106China kunming Hendera Science and Technology Co. Ltd.Kunming 650106China

Bismuth-based anode materials have been regarded as promising Li-ion batteries due to their high theoretical ***,their low conductivity and associated volume expansion inhabited their *** this work,Bi_(2)O_(2)CO_(3)@C composites were successfully synthesized by in situ anchoring of flower-like Bi_(2)O_(2)CO_(3) nanosheets on a carbon-based substrate via *** unique composited structure of Bi_2O_(2)-CO_(3)@C leads to a stable specific capacity of 547 mAh·g^(-1)after 100 cycles at a current density of 0.1 A·g^(-1).Notably,it demonstrates excellent rate capability with a specific capacity of 210 mAh·g^(-1)at 5 A·g^(-1).After 550 cycles at a current density of 0.5 A·g^(-1),a high reversible capacity of nearly 400 mAh·g^(-1)was ***,in situ X-ray diffraction measurements clearly demonstrate the conversion between Bi and Li_(3)Bi during alloying/dealloying,confirming the good electrochemical reversibility of the materials for Li *** reaction kinetics of Bi_(2)O_(2)CO_(3)@C were further investigated using galvanostatic intermittent titration ***,Bi_2O_(2)-CO_(3)@C exhibited excellent long-term stability,maintaining its high reversible capacity for over 200 cycles at a current density of 0.5 A·g^(-1)in a full cell configuration using Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) as the cathode *** result further underscores its promising potential for lithium-ion *** work may provide inspiration for the design of alloy-type negative electrode materials for high-performance rechargeable batteries.

关键词： Bi_(2)O_(2)CO_(3) Composite materials Anode materials Full batteries

Microwave irradiation-induced alterations in physicochemical properties and methane adsorption capability of coals:An experimental study using carbon molecular sieve

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Chinese Journal of Chemical Engineering 2024年第4期68卷 165-180页

作者： Xuexiang Fu Xing Tang Yi Xu Xintao Zhou Dengfeng Zhang Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China

In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of *** this work,the carbon molecular sieve combined with KMnO_(4)oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees,which can serve as model substances toward ***,the microwave irradiation dependences of pores,functional groups,and highpressure methane adsorption characteristics of model substances were *** results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups,which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve;meanwhile,naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 *** alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%,suggesting that microwave irradiation could promote methane ***,the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 *** summary,the oxidized carbon molecular sieve can act as model substances toward coals with different ***,microwave irradiation is a promising technology to enhance coalbed methane recovery.

关键词： Microwave irradiation Physicochemical property Coal matrix Adsorption Carbon molecular sieve

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

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China Foundry 2024年第3期21卷 257-264页

作者： Yang Li Qing Yu Feng-feng Chen Jia-wen He Hong-mei Yang Meng-nie Li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary