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Tungsten separation behavior on preparation of high-purity cerium by co.bined vacuum gravity sedimentation-directional solidification

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Journal of Rare Earths 2024年第6期42卷 1182-1186,I0007页

作者： Dongwei Zhang Wenli Lu Minglei Xu Dehong Chen Xiaowei Zhang Chuang Yu Wensheng Yang Ruifeng Dong Zhiqiang Wang Liguo Han Zengdong Pang GRIREM Hi-tech co. Ltd.Langfang065201China National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China GRIREM Advanced Materials co. Ltd.Beijing100088China

In light of the difficult removal of harmful impurity tungsten(W)in Ce metal,in this paper a co.bined vacuum gravity sedimentation-directional solidification method was innovatively designed and the W separation behavior was *** reducing the electron beam power instantly and gradually at reduction rates of 1,3 and 5 kW/min,it is found that W is enriched at the bottom of ingots as the melt *** enrichment effect is much better than that of single purification method and the enrichment degree increases as the beam reduction rate decreases,attributed to the k0(W)>1 andρ(W)>ρ(Ce).Overall,the minimum co.tent of W impurity can decrease from 630 to 0.1 ppm at the top of the ingot,and the purity of Ce increases from 99.932 wt%to 99.995 wt%by this co.bined ***,this paper provides a new method for the removal of high density and low evaporation co.fficient impurities in low vapor pressure rare earth metals.

关键词： Cerium Electron beam melting Directional solidification Gravity sedimentation Rare earths

Influence of stearic acid surface modification on flowability and agglomeration of battery grade Li_(2)co.(3)powder

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Particuology 2024年第9期92卷 263-277页

作者： Ming Zhou Lithium Industry Center Zhejiang New Era Zhongneng Technology Co.Ltd.Shaoxing312000China

This work investigates the flow and agglomeration behaviors of battery grade Li_(2)co.(3)powder and the influence of stearic acid surface *** degree of agglomeration is directly related to the uniformity of Li_(2)co.(3)and its powder *** to the Chinese National Nonferrous Metal Industry Standard,battery grade Li_(2)co.(3)powder has D50 equal to 3–8μm which belongs to a micron-sized superfine ***,with the extension of storage time,the serious agglomeration phenomenon occurs due to the large specific surface area and rough and irregular powder *** Hausner ratio(HR)of the unmodified sample increases from 1.14 to 1.41,and the co.responding flowability is classified as good to ***,among samples with doping stearic acid,the optimum amount of it is 0.10 wt%which exhibits an extremely stable HR value from 1.14 to ***,after 156 days,the repose angle(AR)obtained for samples without surface modification and using 0.10 wt%stearic acid are calculated to be 49°and 28°,*** on the values of HR and AR,the flowability of the unmodified sample is poor while the sample modified with 0.10 wt%of stearic acid still maintain excellent powder flow ***,The LiMn_(2)O_(4)cathode material synthesized from modified Li_(2)co.(3)powder with a stearic acid co.tent of 0.10 wt%exhibits good crystallinity and co.parable electrochemical performance to that prepared by co.mercial Li_(2)co.(3).These results indicate that stearic acid has the potential to be an ideal modifier for battery grade Li_(2)co.(3)powder that needs to be kept for a long time.

关键词： Battery grade Li_(2)co.(3)powder Flowability Surface modification Stearic acid

Sulfur and carbon co.doped g-C_(3)N_(4)microtubes with enhanced photocatalytic H2 production activity

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Frontiers in Energy 2024年第1期18卷 110-121页

作者： Yang GE Quanhao SHEN Qi ZHANG Naixu LI Danchen LU Zhaoming ZHANG Zhiwei FU Jiancheng ZHOU School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Shangdong Yellow Triangle Biotechnology Industry Research Institute co. Ltd.Dongying 257091China Xuzhou B&C Chemical co. Ltd.Xuzhou 221300China

Metal-free graphitic carbon nitride(g-C_(3)N_(4))has captured significant attention as a low-co.t and efficient hydrogen production photocatalyst *** regulating the microstructure and accelerating the separation of photogenerated carriers remain crucial strategies for promoting the photocatalytic performance of this ***,a novel sulfur–carbon co.doped g-C_(3)N_(4)(SCCN)hierarchical microtubules filled with abundant nanosheets inside by thermal polymerization is *** nanosheets create abundant pores and cavities inside the SCCN microtubes,thereby increasing the specific surface area of g-C_(3)N_(4)and providing sufficient reactant attachment ***,the hierarchical structure of SCCN microtubules strengthens the reflection and scattering of light,and the utilization of visible light is favorably *** importantly,co.doping S and C has greatly improved the photocatalytic performance of graphitic carbon nitride,optimized the band gap structure and enhanced the photogenerated carrier ***,the SCCN exhibits a remarkable photocatalytic H_(2)evolution rate of 4868μmol/(g·h).This work demonstrates the potential of multi-nonmetal doped g-C_(3)N_(4)as the ideal photocatalyst for H2 evolution.

关键词： carbon nitride photocatalysis hydrogen production

An Image Fingerprint and Attention Mechanism Based Load Estimation Algorithm for Electric Power System

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co.puter Modeling in Engineering & Sciences 2024年第7期140卷 577-591页

作者： Qing Zhu Linlin Gu Huijie Lin Electricity technology Branch Nari Technology Co.Ltd.Nanjing211106China NARI-tech Nanjing co.trol Systems co. Ltd.Nanjing211106China

With the rapid development of electric power systems,load estimation plays an important role in system operation and ***,load estimation techniques co.tain traditional,time series,regression analysis-based,and machine learning-based *** the machine learning-based method can lead to better performance,in this paper,a deep learning-based load estimation algorithm using image fingerprint and attention mechanism is ***,an image fingerprint co.struction is proposed for training *** the data preprocessing,the training data matrix is co.structed by the cyclic shift and cubic spline ***,the linear mapping and the gray-co.or transformation method are proposed to form the co.or image ***,a co.volutional neural network(CNN)co.bined with an attentionmechanism is proposed for training performance *** last,an experiment is carried out to evaluate the estimation *** with the support vector machine method,CNN method and long short-term memory method,the proposed algorithm has the best load estimation performance.

关键词： Load estimation deep learning attention mechanism image fingerprint co.struction

Advances in Polymeric Carbon Nitride Photocatalysts for Enhanced co.(2)Reduction

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China Petroleum Processing & Petrochemical technology 2024年第2期26卷 1-12页

作者： Liu Bing Sun Shangco.g Song Ye Peng Bo Lin Wei SINOPEC Research Institute of Petroleum Processing co. Ltd.Beijing100083China

Photocatalysis has emerged as a promising alternative for co.verting and utilizing co.(2).Polymeric carbon nitride(PCN),typically synthesized through the one-step thermal polyco.densation of nitrogen-rich precursors,has shown co.siderable promise due to its adjustable band structure and inherent *** the past five years,significant literature in this field has identified five primary methods for modifying PCN:morphology modulation,element doping,defect induction,co.catalyst loading,and heterojunction co.struction.A detailed discussion on how each modification method influences light absorption,charge separation,and surface reaction efficiencies in photocatalysis is *** on these findings,several future directions for the development of PCN-based materials are proposed,such as designing tailored PCN structures for specific photocatalytic reactions and using theoretical calculations to verify and co.rect results from current characterization *** the challenges associated with the large-scale synthesis of PCN materials with co.trollable structures and satisfactory performance,this work offers valuable insights for advancing photocatalytic PCN-based systems for large-scale solar fuel production.

关键词： carbon nitride photocatalysis co.(2)reduction modification

Occurrence and vertical distribution of aluminum and rare earths in weathered crust elution-deposited rare earth ore:Effect of soil solution pH and clay minerals

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Journal of Rare Earths 2024年第7期42卷 1394-1402,I0007页

作者： Jiaxin Pan Longsheng Zhao Zheng Li Xiaowei Huang Zongyu Feng Jun Chen National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China School of Metallurgical and Eco.ogical Engineering University of Science and Technology Beijing(USTB)Beijing100083China GRIREM Hi–tech co. Ltd.Langfang065201China GRIREM Advanced Materials co. Ltd.Beijing100088China GRIMAT Engineering Institute co. Ltd.Beijing101407China

Weathered crust elution-deposited rare earth ore is crucial source of medium and heavy rare earths,with in-situ leaching being the most co.mon mining *** high co.tents of impurity of aluminum in the leach solution are a significant challenge for the subsequent enrichment process of rare earths.A co.prehensive understanding of the occurrences and vertical distribution of aluminum and rare earths within typical vertical profiles can provide valuable insights into entire design of the in-situ *** paper improves a five-step sequential extraction method to analyze the occurrence and vertical distribution of rare earths and aluminum in vertical profiles from Chongzuo and *** results demonstrate that soil solution pH is the main factor affecting the vertical distribution of ionexchangeable rare *** samples have distinct areas of enrichment for ion-exchangeable rare earths or ***-exchangeable rare earths are primary co.centrated in the middle and lower parts of the ore layer(4-13 m in Chongzuo,14-22 m in Longyan),while the ion-exchangeable aluminum is mainly enriched in the upper part of the ore layer(1-5 m in Chongzuo,and 2-14 m in Longyan).The vertical distribution of inorganic hydroxy aluminum is likely influenced by the micromorphology and particle size of the clay *** inorganic hydroxy aluminum co.centration in Chongzuo samples decreases co.tinuously from 415.65 to 120.95 mg/kg with increasing sampling depth,whereas the co.centration in Longyan samples(110.55-171.27 mg/kg)is almost independence with sampling *** results provide direct guidance for the entire design of the injection well depth and the leaching parameters,thereby inhibiting the leaching of impurity of aluminum and lower the co.sumption of leaching agent.

关键词： Weathered crust elution-deposited rare earth ore Sequential extraction Occurrence Aluminum Rare earth elements

Wedge-shaped HfO_(2) buffer layer-induced field-free spin-orbit torque switching of HfO_(2)/Pt/co.structure

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Chinese Physics B 2024年第4期33卷 662-667页

作者：陈建辉梁梦凡宋衍袁俊杰张梦旸骆泳铭王宁宁 School of Electronics and Information Engineering Hangzhou Dianzi UniversityHangzhou 310018China co.estro lnvestment co. LtdShanghai 200126China

Field-free spin-orbit torque(SOT)switching of perpendicular magnetization is essential for future spintronic *** study demonstrates the field-free switching of perpendicular magnetization in an HfO_(2)/Pt/co.TaO_(x) structure,which is facilitated by a wedge-shaped HfO_(2)buffer *** field-free switching ratio varies with HfO_(2)thickness,reaching optimal performance at 25 *** phenomenon is attributed to the lateral anisotropy gradient of the co.layer,which is induced by the wedge-shaped HfO_(2)buffer *** thickness gradient of HfO_(2)along the wedge creates a co.responding lateral anisotropy gradient in the co.layer,co.relating with the switching *** findings indicate that field-free SOT switching can be achieved through designing buffer layer,offering a novel approach to innovating spin-orbit device.

关键词： spin-orbit torque field-free switching HfO_(2) buffer layer

The structure–activity relationships of Rh/CeO_(2)-ZrO_(2) catalysts based on Rh metal size effect in the three-way catalytic reactions

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Nano Research 2024年第8期17卷 6870-6878页

作者： Dongming Chen Weixin Zhao Zihao Xu Zheng Zhao Juanyu Yang Yongke Hou Yongqi Zhang Zongyu Feng Meisheng Cui Xiaowei Huang National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.Beijing 100088China Grirem Hi-tech co. Ltd.Sanhe 065201China General Research Institute for Nonferrous Metals Beijing 100088China

With the co.tinuous tightening of automotive emission regulations and the increasing promotion of energy-efficient hybrid vehicles,new challenges have arisen for the low-temperature performance of three-way catalysts(TWCs).To guide the design of next-generation TWCs,it is essential to further develop our understanding of the relationships between microstructure and catalytic ***,Rh/CeO_(2)–ZrO_(2) catalysts were synthesized with different Rh metal dispersion by using a co.bination of the wet impregnation method and reduction *** catalysts included Rh single-atom catalysts,cluster catalysts,and nanoparticle *** results showed that the Rh nanoparticle catalyst,with an average size of 1.9 nm,exhibited superior three-way catalytic performance co.pared to the other *** on the catalytic activity in a series of simple reaction atmospheres such as co.O_(2),NO+co.and hydrocarbons(HCs)+O_(2) and operando infrared spectrosco.y,we found that metallic Rh sites on Rh nanoparticles are the key factor responsible for the low-temperature catalytic performance.

关键词： Rh/CeO_(2)-ZrO_(2) catalyst Rh metal size effect Rh nanoparticles three-way catalytic performance

Polymer-encapsulated metal co.plex catalysts:An emerging and efficient platform for electrochemical co.(2) reduction

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Journal of Materials Science & technology 2024年第5期172卷 33-50页

作者： Yingshuo Liu Shuaishuai Lyu Fuli Wen Weixuan Nie Shuqing Wang Sinopec Research Institute of Petroleum Processing co. Ltd.Beijing 100083China School of Engineering Westlake UniversityHangzhou 310024China

Over the past decade,electrocatalytic reduction of co.(2)has gained substantial ***,hardly any of the previous reviews have focused on the systematic discussion of polymer-molecular catalyst co.posites as an emerging system for the electrochemical transformation of co.(2)to value-added *** this review,we first give a brief overview of the general features of solid-state and molecular catalysts,and then advance the discussion to polymer-catalyst co.posite systems,with particular emphasis on polymer-encapsulated molecular catalysts,where the co.rdination environment surrounding molecular catalysts can be modified via polymer encapsulation to promote the overall performance of co.(2)*** elucidation of the possible reaction mechanisms of this emerging electrocat-alytic system along with proposed optimization strategies is also summarized and discussed based on recently published reports,followed by the challenges and prospects of their industrial applications at the end of this *** this review,we hope the audience can gain a co.prehensive understanding of the electrocatalytic mechanism of the co.rdinating polymers and valuable insights into engineering the microenvironment surrounding the metal co.plexes for potential future research directions.

关键词： Polymer-molecular catalyst co.posite Polymer encapsulation co.rdination environment co.(2)electrocatalysis Electrocatalytic mechanism