检索结果-南通市图书馆

Precise regulation of the phase transformation for pyrolusite during the reduction roasting process

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 81-90页

作者： Ruofeng Wang peng gao Shuai Yuan Yanjun Li Yingzhi Liu Cheng Huang School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China National-Local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources Shenyang 110819China

The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore resources.According to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously.

关键词： pyrolusite phase transformation reduction roasting microstructural evolution reaction mechanism

Recent process developments in beneficiation and metallurgy of rare earths:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 629-642页

作者： Shaokai Cheng Wenbo Li Yuexin Han Yongsheng Sun peng gao Xiaolong Zhang School of Resources and Civil Engineering Northeastern UniversityShenyang110819China National-local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources Shenyang110819China

Rare earth elements(REEs)are irreplaceable materials supporting low-carbon technology and equip-ment,and their commercial demand and strategic position are becoming increasingly prominent.With the continuous depletion of rare earth(RE)resources,developing high-efficiency beneficiation and eco-friendly metallurgical processes has attracted widespread attention.This paper reviews the major minerals exploited for RE production and their deposits,as well as the beneficiation and metallurgical processes of RE minerals.Bastnaesite,monazite,mixed RE ores,and ion-adsorption clays are the main raw materials in the world to date.RE-bearing ores(except ion-adsorption minerals)are generally beneficiated by flotation,gravity and magnetic separation techniques.The mainstream metallurgical processes for bastnaesite,monazite and mixed RE concentrates are oxidation roasting-HCl leaching,caustic soda decomposition and high-temperature concentrated sulfuric acid roasting,respectively.Ion-adsorption clays are directly processed by in situ leaching-precipitation/solvent extraction.To achieve the sustainable development of RE resources,it is essential to further explore innovative techniques to achievecomprehensive utilization and cleaner production.

关键词： Rare earths Beneficiation processes Metallurgical processes Cleaner production

Unveiling the surface-interface properties of perovskite crystals and pivotal regulation strategies

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3950-3981页

作者： Qin Li Ziyu Wang Junjie Ma Mengqi Han peng gao Meng Cai Yiqiang Zhang Yanlin Song Shou peng Henan Institute of Advanced Technology College of ChemistryZhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of Sciences(ICCAS)Beijing 100190China China National Building Material Group Co. Ltd.Beijing 100036China State Key Laboratory of Advanced Technology for Float Glass Beijing 100036China

Metal-halide perovskite solar cells have garnered significant research attention in the last decade due to their exceptional photovoltaic performance and potential for commercialization.Despite achieving remarkable power conversion efficiency of up to 26.1%,a substantial discrepancy persists when compared to the theoretical Shockley-Queisser(SQ)limit.One of the most serious challenges facing perovskite solar cells is the energy loss incurred during photovoltaic conversion,which affects the SQ limits and stability of the device.More significant than the energy loss occurring in the bulk phase of the perovskite is the energy loss occurring at the surface-interface.Here,we provide a systematic overview of the physical and chemical properties of the surface-interface.Firstly,we delve into the underlying mechanism causing the energy deficit and structural degradation at the surface-interface,aiming to enhance the understanding of carrier transport processes and structural chemical reactivity.Furthermore,we systematically summarized the primary modulating pathways,including surface reconstruction,dimensional construction,and electric-field regulation.Finally,we propose directions for future research to advance the efficiency of perovskite solar cells towards the radiative limit and their widespread commercial application.

关键词： perovskite solar cells surface-interface treatment defect modification dimensional design energy regulation heterojunction and homojunction

Investigation on Degradation Path of SF_(6)in Packed-bed Plasma:Effect of Plasma-generated Radicals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 1231-1241页

作者： Zhaolun Cui Chang Zhou Amin Jafarzadeh Xiaoxing Zhang peng gao Licheng Li Yanpeng Hao School of Electric Power Engineering South China University of TechnologyGuangzhou 510630China School of Electrical and Electronic Engineering Hubei University of TechnologyWuhan 430068China Research group PLASMANT Department of ChemistryUniversity of AntwerpUniversiteitsplein 1BE-2610 Wilrijk-AntwerpBelgium CSEE

SF_(6)degradation mechanism in non-thermal plasma(NTP)systems is not fully understood due to the formation of a complex physico-chemical reaction network,especially when reactive gases and packing materials are involved.In this work,we conduct a combined experimental and theoretical study to unravel the SF_(6)degradation path in a-Al_(2)O_(3)packed plasma in the presence of H_(2)O or O_(2).Our experimental results show that both H_(2)O and O_(2)have a synergetic effect with-Al_(2)O_(3)packing on promoting SF_(6)degradation,leading to higher stable gas yields than typical spark or corona discharges.H_(2)O or O_(2)addition promotes SO_(2)or SO_(2)F_(2)selectivity,respectively.Density functional theory(DFT)calculations reveal that SO_(2)generation corresponding with the highest activation barrier is the most critical step toward SF_(6)degradation.Radicals like H and O generated from H_(2)O or O_(2)discharge can significantly promote the degradation process via Eley-Rideal mechanism,affecting key reactions of stable product generation,advancing degradation efficiency.The results of this work could provide insights on further understanding SF_(6)degradation mechanism especially in packed-bed plasma systems.

关键词： Degradation mechanism packed-bed plasma radicals SF_(6)

Advancements in machine learning for material design and process optimization in the field of additive manufacturing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第2期21卷 101-115页

作者： Hao-ran Zhou Hao Yang Huai-qian Li Ying-chun Ma Sen Yu Jian shi Jing-chang Cheng peng gao Bo Yu Zhi-quan Miao Yan-peng Wei National Key Laboratory of Advanced Casting Technologies Shenyang Research Institute of Foundry Co.Ltd.CAMShenyang 110022China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Key Laboratory of Space Physics Beijing 100076China School of Materials Science and Engineering Nanyang Technological University639798Singapore

Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric challenges.However,the development of additive manufacturing process is constrained by issues like unclear fundamental principles,complex experimental cycles,and high costs.Machine learning,as a novel artificial intelligence technology,has the potential to deeply engage in the development of additive manufacturing process,assisting engineers in learning and developing new techniques.This paper provides a comprehensive overview of the research and applications of machine learning in the field of additive manufacturing,particularly in model design and process development.Firstly,it introduces the background and significance of machine learning-assisted design in additive manufacturing process.It then further delves into the application of machine learning in additive manufacturing,focusing on model design and process guidance.Finally,it concludes by summarizing and forecasting the development trends of machine learning technology in the field of additive manufacturing.

关键词： additive manufacturing machine learning material design process optimization intersection of disciplines embedded machine learning

Nickel-modified In_(2)O_(3) with inherent oxygen vacancies for CO_(2) hydrogenation to methanol

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1715-1728页

作者： Zixuan Zhou Yuchen Wang Yuanjie Bao Haiyan Yang Jiong Li Chunran Chang Shenggang Li peng gao CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization School of Chemistry and Chemical EngineeringYulin UniversityYulin 719000China

Methanol synthesis is one of the most important industrially-viable approaches for carbon dioxide(CO_(2)) utilization, as the produced methanol can be used as a platform chemical for manufacturing green fuels and chemicals. The In_(2)O_(3) catalysts are ideal for sustainable methanol synthesis and have received considerable attention. Herein, Co-, Ni-and Cu-modified In_(2)O_(3) catalysts were fabricated with high dispersion and high stability to improve the hydrogenation performance. The Ni-promoted In_(2)O_(3) catalyst in the form of high dispersion possessed the largest amount of oxygen vacancies and the strongest ability for H_(2) activation, leading to the highest CO_(2) conversion and space time yield of methanol of 0.390 g_(Me OH)g_(cat)^(-1)h^(-1) with CH_(3)OH selectivity of 68.7%. In addition, the catalyst exhibits very stable performance over 120 h on stream, which suggests the promising prospect for industrial applications. Further experimental and theoretical studies demonstrate that surface Ni doping promotes the formation of oxygen defects on the In_(2)O_(3) catalyst, although it also results in lower methanol selectivity. Surprisingly, subsurface Ni dopants are found to be more beneficial for methanol formation than surface Ni dopants, so the Nipromoted In_(2)O_(3)catalyst with a lower surface Ni content at the similar Ni loading can reach higher methanol selectivity and productivity. This work thus provides theoretical guidance for significantly improving the CO_(2) reactivity of In_(2)O_(3)-based catalysts while maintaining high methanol selectivity.

关键词： carbon dioxide hydrogenation methanol synthesis indium oxides Ni doping sites transition metal promoters

Interface engineering strategy via electron-defect trimethyl borate additive toward 4.7 V ultrahigh-nickel LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)battery

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第5期92卷 639-647页

作者： Yilin Zhang Yuqing Chen Qiu He Jinlong Ke Wei Wang Jian-Fang Wu peng gao Yanhua Li Jilei Liu College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean EnergyHunan Province Key Laboratory for Advanced Carbon Materials and Applied TechnologyHunan UniversityChangsha 410082HunanChina College of Materials Science and Engineering Sichuan UniversityChengdu 610065SichuanChina School of Materials Science and Engineering Hunan Institute of TechnologyHengyang 421002HunanChina

The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,the practical application is impeded by the instability of electrode/electrolyte interface and Ni-rich cathode itself.Herein we proposed an electron-defect electrolyte additive trimethyl borate(TMB)which is paired with the commercial carbonate electrolyte to construct highly conductive fluorine-and boron-rich cathode electrolyte interface(CEI)on LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)surface and solid electrolyte interphase(SEI)on lithium metal surface.The modified CEI effectively mitigates the structural transformation from layered to disordered rock-salt phase,and consequently alleviate the dissolution of transition metal ions(TMs)and its“cross-talk”effect,while the enhanced SEI enables stable lithium plating/striping and thus demonstrated good compatibility between electrolyte and lithium metal anode.As a result,the common electrolyte with 1 wt%TMB enables 4.7 V NCM90/Li cell cycle stably over 100 cycles with 70%capacity retention.This work highlights the significance of the electron-defect boron compounds for designing desirable interfacial chemistries to achieve high performance NCM90/Li battery under high voltage operation.

关键词： NCM90 batteries Electrolyte additive Trimethyl borate

Covalency competition induced selective bond breakage and surface reconstruction in manganese cobaltite towards enhanced electrochemical charge storage

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第5期9卷 909-918页

作者： peng gao Pei Tang Ying Mo Peitao Xiao Wang Zhou Shi Chen Hongliang Dong Ziwei Li Chaohe Xu Jilei Liu College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean EnergyHunan Province Key Laboratory for Advanced Carbon Materials and Applied TechnologyHunan UniversityChangshaHunan410082China Department of Materials Science and Engineering National University of Defense TechnologyChangshaHunan410073China Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoAvenida da UniversidadeTaipaMacao999078China Center for High Pressure Science and Technology Advanced Research PudongShanghai201203China College of Aerospace Engineering Chongqing UniversityChongqing400044China

Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn are prone to react with the hydroxyl ions in alkaline electrolyte upon electrochemical cycling and separates on the surface of spinel to reconstruct into d-MnO_(2) nanosheets irreversibly,thus results in a change of the reaction mechanism with Kþion intercalation.However,the low capacity has greatly limited its practical application.Herein,we found that the tetrahedrally-coordinated Co_(2) þions were leached when MnCo_(2)_(4) was equilibrated in 1 mol L^(-1) HCl solution,leading to the formation of layered CoOOH on MnCo_(2)_(4) surface which is originated from the covalency competition induced selective breakage of the CoT–O bond in CoT–O–CoO and subsequent rearrangement of free Co_(6) octahedra.The as-formed CoOOH is stable upon cycling in alkaline electrolyte,exhibits conversion reaction mechanism with facile proton diffusion and is free of massive structural evolution,thus enables utilization of the bulk electrode material and realizes enhanced speciﬁc capacity as well as facilitated charge transfer and ion diffusion.In general,our work not only offers a feasible approach to deliberate modiﬁcation of MnCo_(2)_(4)'s surface structure,but also provides an in-depth understanding of its charge storage mechanism,which enables rational design of the spinel oxides with promising charge storage properties.

关键词： Manganese cobaltite Tetrahedrally-coordinated Co^(2+)leaching Selective bond breakage Surface reconstruction Charge storage mechanisms

Genetically predicted waist circumference and risk of atrial fibrillation

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2024年第1期137卷 82-86页

作者： Wenting Wang Jiang-shan Tan Jingyang Wang Wei Xu Liting Bai Yu Jin peng gao Peiyao Zhang Yixuan Li Yanmin Yang Jinping Liu Department of Cardiopulmonary Bypass State Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100037China Department of Anaesthesiology Second Affiliated HospitalHainan Medical CollegeHaikouHainan 570311China State Key Laboratory of Cardiovascular Disease Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100037China

Introduction:Observational studies have revealed an association between waist circumference(WC)and atrial fibrillation(AF).However,it is difficult to infer a causal relationship from observational studies because the observed associations could be confounded by unknown risk factors.Therefore,the causal role of WC in AF is unclear.This study was designed to investigate the causal association between WC and AF using a two-sample Mendelian randomization(MR)analysis.Methods:In our two-sample MR analysis,the genetic variation used as an instrumental variable for MR was acquired from a genome-wide association study(GWAS)of WC(42 single nucleotide polymorphisms with a genetic significance of P<5×10^(-8)).The data of WC(from the Genetic Investigation of ANthropometric Traits consortium,containing 232,101 participants)and the data of AF(from the European Bioinformatics Institute database,containing 55,114 AF cases and 482,295 controls)were used to assess the causal role of WC on AF.Three different approaches(inverse variance weighted[IVW],MR-Egger,and weighted median regression)were used to ensure that our results more reliable.Results:All three MR analyses provided evidence of a positive causal association between high WC and AF.High WC was suggested to increase the risk of AF based on the IVW method(odds ratio[OR]=1.43,95%confidence interval[CI],1.30-1.58,P=2.51×10^(-13)).The results of MR-Egger and weighted median regression exhibited similar trends(MR-Egger OR=1.40[95%CI,1.08-1.81],P=1.61×10^(-2);weighted median OR=1.39[95%CI,1.21-1.61],P=1.62×10^(-6)).MR-Egger intercepts and funnel plots showed no directional pleiotropic effects between high WC and AF.Conclusions:Our findings suggest that greater WC is associated with an increased risk of AF.Taking measures to reduce WC may help prevent the occurrence of AF.

关键词： Genetically predicted Waist circumference Atrial fibrillation Mendelian randomization