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Journal of Rare Earths 2024年第9期42卷 1774-1781,I0005页

作者： Delong Yang Mingming Yu Yusufujiang Mubula Weiquan Yuan Zheyu Huang Bo Lin Guangjun Mei Tingsheng Qiu school of Resources and environmental engineering Jiangxi University of Science and TechnologyGanzhou341000China Jiangxi Key Laboratory of Mining engineering Jiangxi University of Science and TechnologyGanzhou341000China school of Resources and environmental engineering Wuhan University of TechnologyWuhan430070China Gannan Institute of Science and Technology Ganzhou341000China

Viewing the problem of high ene rgy consumption in the process of recovering rare earths from rare earth molten salt electrolysis slag,an environmentally friendly and low carbon process by sub-molten salt decomposition was *** thermodynamic analysis of sub-molten salt reaction indicates that the recovery of rare earths from the slag using sub-molten salt medium is thermodynamically *** this process,the rare earth fluoride and lithium in the slag are almost transformed into rare earth hydroxide,sodium fluoride and lithium hydroxide,fluorine and lithium are transferred into the washing solution,and the rare earths in the residues can be leached into solution by acid *** the optimum reaction conditions of reaction temperature 200℃,reaction time 3 h,NaOH initial concentration 80%,NaOH-Slag mass ratio 3:1,the leaching efficiency of rare earths,fluorine and lithium can reach to 99.05%,98.23% and 99.22%.After evaporation,the fluorine and lithium in the washing solution can be obtained in the forms of sodium fluoride and lithium fluoride,the recovery efficiency reach 95.5%and 92.8%,*** RE oxides(99.53%) can be obtained from the leaching solution after precipitation and roasting.

关键词： Rare earth electrolysis slag Sub-molten salt Green extraction Fluorine Lithium Recovery

Predicting torsional capacity of reinforced concrete members by data-driven machine learning models

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Frontiers of Structural and Civil engineering 2024年第3期18卷 444-460页

作者： Shenggang CHEN Congcong CHEN Shengyuan LI Junying GUO Quanquan GUO Chaolai LI school of Mechanics and Civil engineering China University of Mining and TechnologyXuzhou 211116China Jiangsu Key Laboratory environmental Impact and Structural Safety in engineering China University of Mining and TechnologyXuzhou 211116China China Nuclear Power Design Co.Ltd. Shenzhen 518031China school of transportation and science engineering Beihang UniversityBeijing 100191China China construction First Group Corporation Limited Beijing 100161China

Due to the complicated three-dimensional behaviors and testing limitations of reinforced concrete(RC)members in torsion,torsional mechanism exploration and torsional performance prediction have always been *** the present paper,several machine learning models were applied to predict the torsional capacity of RC *** results of a total of 287 torsional specimens were collected through an overall literature *** of extreme gradient boosting machine(XGBM),random forest regression,back propagation artificial neural network and support vector machine,were trained and tested by 10-fold cross-validation *** performances of proposed machine learning models were evaluated and compared,both with each other and with the calculated results of existing design codes,i.e.,GB 50010,ACI 318-19,and Eurocode *** results demonstrated that better predictive performance was achieved by machine learning models,whereas GB 50010 slightly overestimated the torsional capacity,and ACI 318-19 and Eurocode 2 underestimated it,especially in the case of ACI *** XGBM model gave the most favorable predictions with R^(2)=0.999,RMSE=1.386,MAE=0.86,andλ=***,strength of concrete was the most sensitive input parameters affecting the reliability of the predictive model,followed by transverse-to-longitudinal reinforcement ratio and total reinforcement ratio.

关键词： RC members torsional capacity machine learning models design codes

Modeling and analysis of gradient metamaterials for broad fusion bandgaps

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1155-1170页

作者： Changqi CAI Chenjie ZHU Fengyi ZHANG Jiaojiao SUN Kai WANG Bo YAN Jiaxi ZHOU school of Mechanical engineering Zhejiang Sci-Tech UniversityHangzhou310018China school of Material and environmental engineering Hangzhou Dianzi UniversityHangzhou310018China College of Mechanical and Vehicle engineering Hunan UniversityChangsha410082China

A gradient metamaterial with varying-stiffness local resonators is proposed to open the multiple bandgaps and further form a broad fusion ***,three local resonators with linearly increasing stiffness are periodically attached to the spring-mass chain to construct the gradient *** dispersion relation is then derived based on Bloch's theorem to reveal the fusion bandgap *** dynamic characteristic of the finite spring-mass chain is investigated to validate the fusion of multiple ***,the effects of the design parameters on multiple bandgaps are *** results show that the metamaterial with a non-uniform stiffness gradient pattern is capable of opening a broad fusion bandgap and effectively attenuating the longitudinal waves within a broad frequency region.

关键词： local resonance mechanism elastic metamaterial stiffness gradient bandgap fusion broadband wave attenuation

Nonlinear constitutive models of rock structural plane and their applications

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Journal of Rock Mechanics and Geotechnical engineering 2024年第3期16卷 790-806页

作者： Wenlin Feng Shuangjian Niu Chunsheng Qiao Dujian Zou school of Civil and environmental engineering Harbin Institute of TechnologyShenzhenChina Shenzhen Municipal engineering Corporation Shenzhen518000China school of Civil engineering Beijing Jiaotong UniversityBeijing100044China

Structural planes play an important role in controlling the stability of rock engineering,and the influence of structural planes should be considered in the design and construction process of rock *** this paper,mechanical properties,constitutive theory,and numerical application of structural plane are studied by a combination method of laboratory tests,theoretical derivation,and program *** test results reveal the change laws of various mechanical parameters under different roughness and normal *** the pre-peak stage,a non-stationary model of shear stiffness is established,and threedimensional empirical prediction models for initial shear stiffness and residual stage roughness are *** nonlinear constitutive models are established based on elasto-plastic mechanics,and the algorithms of the models are developed based on the return mapping *** to a large number of statistical analysis results,empirical prediction models are proposed for model parameters expressed by structural plane characteristic ***,the discrete element method(DEM)is chosen to embed the constitutive models for practical *** running programs of the constitutive models have been compiled into the discrete element model *** comparison results between the proposed model and the Mohr-Coulomb slip model show that the proposed model can better describe nonlinear changes at different stages,and the predicted shear strength,peak strain and shear stiffness are closer to the test *** research results of the paper are conducive to the accurate evaluation of structural plane in rock engineering.

关键词： Structural plane engineering stability Roughness Normal stress Elasto-plastic constitutive model Discrete element method

Unravelling the nature of the active species as well as the Mn doping effect over gamma-Al_(2)O_(3) catalyst for eliminating AsH_(3) and PH_(3)

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Journal of environmental Sciences 2024年第2期136卷 213-225页

作者： Bowen Xu Jiaxin Qu Xueqian Wang Langlang Wang Yu Pu Ping Ning Yibing Xie Yixing Ma Qiang Ma Faculty of environmental Science and engineering Kunming University of Science and TechnologyKunming 650500China school of Architecture and Civil engineering Chengdu UniversityChengdu 610106China

To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3)catalysts were *** characteristics of the catalysts showed that Mn reduced the crystallinity of the active CuO component,increased the number of oxygen vacancies and acidic sites on the catalyst surface,enhanced the mobility of surface oxygen,and the interaction between copper and manganese promoted the redox cycling ability of the catalysts and improved their oxidation performance,which increased the conversion frequency(TOF)by 2.54×10^(-2)to 3.07×10^(-2)sec^(-1).On the other hand,the introduction of Mn reduced the production of phosphate and As_(2)O_(3)on the catalyst surface by30.96%and 44.9%,which reduced the coverage and inerting of the active sites by phosphate and As_(2)O_(3),resulting in an 8 hr(6 hr)improvement in the stability of PH_(3)(AsH_(3))removal.

关键词： AsH_(3)-PH_(3)removal Oxygen activation Mn doping Stability enhancement

Numerical investigation of transient gas–solid heat transfer in a packed bed:Impact of intra-particle thermal diffusion

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Particuology 2024年第7期90卷 404-411页

作者： Hanqiao Che Yuanhe Yue Zhaohua Jiang Duan Li school of Mechanical engineering Guangxi UniversityNanningGuangxi530004China school of Chemical engineering University of BirminghamBirminghamB152TTUK Hebei engineering Research Center of Advanced Energy Storage Technology and Equipment School of Energy and Environmental EngineeringHebei University of TechnologyTianjin300401China Hebei Key Laboratory of Thermal Science and Energy Clean Utilization School of Energy and Environmental EngineeringHebei University of TechnologyTianjin300401China school of Mechatronics and Vehicle engineering Chongqing Jiaotong UniversityChongqing400074China school of Instrumentation and Opto-Electronic engineering Beihang UniversityBeijing 100191China

The transient heat transfer behaviours in a packed bed have been studied using coupled computational fluid dynamics(CFD)and discrete element method(DEM).Intra-particle thermal diffusion,which is a crucial but rarely explored issue,is considered by introducing a one-dimensional diffusion equation in the DEM *** achieve a sufficiently long physical time of simulations,we further reduce the computational cost by applying periodic boundary condition to a small segment of the packed *** study demonstrates a shifting peak heat flow rate from the bottom to the top of the packed bed during the initial warming *** affirm that the influence of thermal diffusion within a particle is noteworthy only for particles exhibiting a high Biot number(e.g.,Bi=1.2).This insight enriches our understanding of heat transfer mechanisms in packed beds and their practical engineering applications.

关键词： Packed bed Intra-particle heat transfer CFD–DEM

Unexpected/contrary behavior of aerosol mass concentration in response to the individual components'concentration reduction in Kitakyushu,Japan

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Journal of environmental Sciences 2024年第1期135卷 630-639页

作者： Xi Zhang Takuya Murakami Jinhe Wang Masahide Aikawa Faculty of environmental engineering The University of Kitakyushu1-1HibikinoWakamatsuKitakyushuFukuoka 808-0135Japan Resources and Environment Innovation Research Institute School of Municipal and Environmental EngineeringShandong Jianzhu UniversityJinan 250101China

In the suburbs of Kitakyushu,Japan,the inorganic aerosol mass concentration(IAM)was about 32.7μg/m^(3),with the aerosol pH of *** study the thermodynamics of aerosol when its individual components'concentration is reduced,sensitive tests were performed using the ISORROPIAⅡmodel,in which the seven control species—TNaCl,TNH_(4)^(+),TSO_(4)^(2-),TNO_(3)^(-),TMg^(2+),TK^(+),and TCa^(2+)—were taken into *** and inorganic aerosol pH after reducing TNaCl,TNO_(3)^(-),TMg^(2+),TK^(+),and TCa^(2+)responded linearly(0%≤concentration reduction ratio(CRR)≤100%,with the exception of 100%in TNaCl);the nonlinear variations of these two parameters could be observed by controlling TNH_(4)^(+)and TSO_(4)^(2-).Unexpected aerosol behavior occurred at 100%reduction of TNaCl,which was caused by the sudden increase of NO_(3)^(-),NH_(4)^(+),and aerosol liquid water content(ALWC);the increase of IAM was also observed after controlling TSO_(4)^(2-)(60%≤CRR≤100%)and TCa^(2+)(0%≤CRR≤100%),which was mainly related to the variation of ALWC driven by the response of CaSO_(4).Multiple regression analysis showed that ALWC was statistically and strongly related to the variations of NO_(3)^(-),Cl-,SO_(4)^(2-),HSO_(4)^(-),HNO_(3),and NH_(3)(P<0.05),with regression coefficients of 1.68,5.23,1.83,2.81,0.34,and 0.57,*** highest coefficient(5.23)was found for Cl^(-),revealing that sea salts significantly influenced particle ***,this study comprehensively investigated aerosol characteristics and inner responses for the reduction of components,which is of great significance for a better understanding of atmospheric chemistry in Kitakyushu,Japan.

关键词： Sensitive tests Reduction Gas-particle conversion process Aerosol liquid water content Sea salts

Resistance to salt stresses by aerobic granular sludge:sludge property and microbial community

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Frontiers of environmental Science & engineering 2024年第8期18卷 107-116页

作者： Xiao Wu Hui Li Meili Wang Tianying Zhang Jiawei Li Yongdi Liu Key Laboratory of Pollution Control Chemistry and environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission School of Chemistry and EnvironmentSouthwest Minzu UniversityChengdu 610041China Institute for environmental Pollution and Health School of Environmental and Chemical EngineeringShanghai UniversityShanghai 200444China school of Life Sciences Southwest UniversityChongqing 400715China State environmental Protection Key Laboratory of environmental Risk Assessment and Control on Chemical Process School of Resources and Environmental EngineeringEast China University of Science and TechnologyShanghai 200237China Institute of Qinghai-Tibetan Plateau Southwest Minzu UniversityChengdu 610041China

Saline wastewater is regarded as a challenge for wastewater treatment plants because high-salinity conditions negatively affect on traditional biological *** granular sludge(AGS)has gained attention as a promising technology for saline wastewater treatment because of its compact structure and the ability to withstand toxic ***,this study investigated the saltresistance performance,sludge properties and microbial community of AGS under low-salinity and high-salinity conditions,with the saline concentrations ranging from 0 to 50 g/*** results showed that AGS could withstand long-term saline stresses,and the maximum salinity reached 50 g/L within 113 *** salinities of 10,30,and 50 g/L,the chemical oxygen demand(COD)removal efficiencies were 90.3%,88.0%and 78.0%,*** also its maintained strength and aggregation at salinities of 10 and 30 g/*** of extracellular polymeric substances(EPS)by non-halophilic bacteria that enhanced sludge *** compact structure that ensured the microorganisms bioactivity helped to remove organic matters under salinities of 10 and 30 g/*** a salinity of 50 g/L,moderately halophilic bacteria,including Salinicola,Thioclava,Idiomarina and Albirhodobacter,prevailed in the *** dominant microbial communities shifted to moderately halophilic bacteria,which could maintain aerobic granular stabilization and remove organic matters under 50 g/L *** results in this study provide a further explanation for the long-term operation of AGS for treating saline wastewater at different *** is hoped that this work could bring some clues for the mystery of salt-resistance mechanisms.

关键词： Aerobic granular sludge Long-term saline stresses Performance Sludge property Microbial community

Assessment of the Influence of Tunnel Settlement on Operational Performance of Subway Vehicles

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Structural Durability & Health Monitoring 2024年第1期18卷 55-71页

作者： Gang Niu Guangwei Zhang Zhaoyang Jin Wei Zhang Xiang Liu China Communications construction Rail Transit Subsidiary Beijing100000China China Communications construction Strait construction Investment Development Co. Ltd.Fuzhou350000China school of Civil engineering Fujian University of TechnologyFuzhou350118China

In the realm of subway shield tunnel operations,the impact of tunnel settlement on the operational performance of subway vehicles is a crucial *** study introduces an advanced analytical model to investigate rail geometric deformations caused by settlement within a vehicle-track-tunnel coupled *** model integrates the geometric deformations of the track,attributed to settlement,as track irregularities.A novel“cyclic model”algorithm was employed to enhance computational efficiency without compromising on precision,a claim that was rigorously *** model’s capability extends to analyzing the time-history responses of vehicles traversing settlement-affected *** research primarily focuses on how settlement wavelength,amplitude,and vehicle speed influence operational *** findings indicate that an increase in settlement wavelength can improve vehicle performance,whereas a rise in amplitude can degrade *** study also establishes settlement thresholds,based on vehicle operation comfort and *** insights are pivotal for maintaining and enhancing the safety and efficiency of subway systems,providing a valuable framework for urban infrastructure management and long-term maintenance strategies in metropolitan transit systems.

关键词： Settlement running performance subway tunnel dynamic analysis track irregularity threshold

Tuning interfacial charge transfer for efficient visible-light-driven photodegradation and simultaneous H_(2)evolution

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Journal of Materials Science & Technology 2024年第1期168卷 35-49页

作者： Zhiyang Li Yaogang Chen Yinghe Zhang Wei Ai Qian Lei Tingjun Yao Dan Zhong Wenjie Liu Wenbiao Jin Lei Yang State Key Laboratory of urban Water Resource and Environment Shenzhen Key Laboratory of Organic Pollution Prevention and ControlSchool of Civil and Environmental EngineeringHarbin Institute of Technology ShenzhenShenzhen 518055China Key Laboratory of Northwest Water Resources Environment and EcologyMinistry of EducationSchool of Environmental and Municipal EngineeringXi’an University of Architecture and TechnologyXi’an 710055China CNAS Accredited Test Center Guangdong Engineering Technology Research Center of Air PurificationHealthlead Co.Ltd.Shenzhen 518055China school of Science Harbin Institute of Technology ShenzhenShenzhen 518055China

The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼7.04-fold and∼18.3-fold enhanced visible-light-driven photocatalytic performance for refrac-tory micropollutant removal and simultaneous hydrogen(H_(2))evolution respectively compared to con-ventional ZnO/g-C_(3)N_(4)Step-scheme *** apparent quantum efficiency of the ZCN_(0.4)het-erojunction reaches 0.92%(λ=420 nm).Such excellent performance stems from that the edge-graphene moieties stitched onto the interface of heterojunction extend light absorption to the full visible spec-trum,meanwhile,the built-in electric field generated during Fermi level alignment accompanying fa-vorable band-bending structure provides an effective pathway for the rapid migration of photoinduced electrons via the edge graphene channel to improve interfacial charge separation ***,the midgap states introduced in ZCN heterojunction could temporarily retain photoexcited electrons to effectively inhibit the in situ carrier recombination for improved photocatalytic H_(2)***,ZCN/peroxymonosulfate system exhibited excellent anti-interference performance against complex water bodies under visible illumination due to the synergistic effect between the co-existing anions and organic ***,the eco-friendly nature of the ZCN/peroxymonosulfate system showed no biotoxicity of reaction filtrate on cell proliferation after treatment,which avoided secondary ***-ering the outstanding performance in photocatalysis,the ZCN system exhibits broad potential for practical applications in water pollution control and green energy production.

关键词： ZnO C_(3)N_(4)-C g Heterojunction Photodegradation Hydrogen evolution