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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

Effect of Heat Treatment on Microstructure and Mechanical Properties of Multiscale SiC_p Hybrid Reinforced 6061 Aluminum Matrix co.posites

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 174-181页

作者：吴健铭许晓静 ZHANG Xu LUO Yuntian LI Shuaidi HUANG Lin Institute for advanced manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang 212013China

The performance of solid solution aging treatment on aluminum matrix co.posites prepared by powder metallurgy and reinforced with 6061 aluminum alloy powder as matrix;meanwhile, nano silico. carbide particles(nm Si Cp), submicron silico. carbide particles(1 μm Si Cp) and Ti particles were studied. The Al/Si Cp co.posite powder was prepared by high-energy ball milling, and then co.d-pressed, sintered, hotextruded, and then heat-treated with different solution temperatures and aging times for the extruded co.posites. Optical microsco.y, scanning electron microsco.y, energy dispersive X-ray spectrosco.y(EDS), X-ray diffractometer(XRD) and extrusion testing were used to analyze and test the microstructure and mechanical properties of aluminum matrix co.posites. The results show that after the multi-stage solid solution at 530 ℃×2 h+535 ℃×2 h+540 ℃×2 h, the particles are mainly equiaxed grains and uniformly distributed. There is no reinforcement agglomeration, and the surface is dense and the insoluble phase is basically dissolved. In the matrix, the strengthening effect is good, and the hardness and co.pressive strength are 179.43 HV and 680.42 MPa, respectively. Under this solution process, when the aluminum matrix co.posites are aged at 170 ℃ for 10 h, the hardness and co.pressive strength can reach their peaks and increase to 195.82 HV and 721.48 MPa, respectively.

关键词： aluminum matrix co.posites Si C particles multiscale hybrid enhancement heat treatment mechanical properties

In-situ analysis of laser-induced breakdown spectra for online monitoring of femtoseco.d laser machining of sapphire

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Science China(Technological Sciences) 2024年第1期67卷 73-82页

作者： SHANGGUAN ShiYong ZHANG JianGuo LI ZhanZhu SHI Wei WANG WenKe QI DongFeng ZHENG HongYu Center for advanced Laser manufacturing(CALM) Shandong University of TechnologyZibo 255000China

Laser-induced breakdown spectrosco.y(LIBS)is widely used for elemental ***,its application for monitoring and analyzing a laser machining process by examining the changes in spectral information warrants further *** this study,we investigate the effect of laser parameters on the spectra,variations in the time-resolved plasma emission spectra,and the relationship between the morphology of craters and plasma plume evolution during the femtoseco.d(fs)laser ablation of *** Boltzmann plot method and Stark’s broadening model are employed to estimate the temporal temperature and electron density of the plasma plume,revealing the process of plasma *** study aims to demonstrate the feasibility of LIBS for online monitoring of laser processing through experimental data and theoretical explanations.

关键词： laser-induced breakdown spectrosco.y plasma plume online monitoring sapphire

Surface roughness classification using light scattering matrix and deep learning

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Science China(Technological Sciences) 2024年第2期67卷 520-535页

作者： SUN Hao TAN Wei RUAN YiXiao BAI Long XU JianFeng State Key Laboratory of Intelligent manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Wuhan Digital Design and manufacturing Innovation Center co. LtdWuhan 430074China

High-quality optical co.ponents have been widely used in various applications;thus,extremely high beam quality is ***,surface roughness is a key indicator of the surface *** this study,the angular distribution of light scattering field intensity was obtained for surfaces having different roughness profiles based on the finite difference time domain(FDTD)method,and the results were co.pared with those obtained using the generalized Harvey-Shack(GHS)*** was shown that the FDTD approach can be used for an accurate simulation of the scattered field of a rough surface,and the superposition of results obtained from many surfaces that have the same roughness level was in good agreement with the result given by the analytic GHS model.A light scattering matrix(LSM)method was proposed based on the FDTD simulation results that co.ld obtain rich surface roughness *** classification effect of LSM was co.pared with that of the single-incidence scattering distribution(SISD)based on a ResNet-50 deep learning *** classification accuracy of the model trained with the LSM dataset was obtained as 95.74%,which was 23.40%higher than that trained using the SISD ***,the effects of different noise types and filtering methods on the classification performance were analyzed,and the LSM was also shown to improve the robustness and generalizability of the trained surface roughness ***,the proposed LSM method has important implications for improving the data acquisition scheme of current light scattering measurement systems,and it also has the potential to be used for detection and characterization of surface defects of optical co.ponents.

关键词： surface roughness FDTD simulation GHS theory deep learning light scattering matrix

Quasi-in-situ Observation and SKPFM Studies on Phosphate Protective Film and Surface Micro-Galvanic co.rosion in Biological Mg-3Zn-xNd Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 648-664页

作者： Zhaochen Yu Kaixuan Feng Shuyun Deng Yang Chen Hong Yan Honggun Song Chao Luo Zhi Hu School of advanced manufacturing Nanchang UniversityNanchang330031China Institute for advanced Study Nanchang UniversityNanchang330031China

The phosphate protective film and micro-galvanic co.rosion of biological Mg-3Zn-xNd (x = 0, 0.6, 1.2) alloys were investigated by scanning and transmission electron microsco.y, quasi-in-situ observation, scanning Kelvin probe force microsco.y (SKPFM) and electrochemical tests. The results revealed the Mg-Zn-Nd phases formed in Mg-3Zn alloy co.tained with Nd. Adding Nd resulted in a significant decline in the cracks of the phosphate protective film and micro-galvanic co.rosion of alloys, which were reco.ded by quasi-in-situ observation. In addition, the Volta potential difference of Mg-Zn-Nd/α-Mg (~ 188 mV) was lower than MgZn/α-Mg (~ 419 mV) and Zn-rich/α-Mg (~ 260 mV), and the co.rosion rates of alloys markedly decreased after the addition of 0.6 wt% Nd. The improvement in co.rosion resistance of Nd-co.taining alloys was mainly attributed to the following: (i) the addition of Nd reduced the Volta potential difference (seco.d phases/α-Mg);(ii) the phosphate protective film co.taining Nd_(2)O_(3) deposited on the surface of the alloys, effectively preventing the penetration of harmful anions.

关键词： Magnesium alloys Quasi-in-situ observation Phosphate protective film Scanning Kelvin probe force microsco.y(SKPFM) Micro-galvanic co.rosion

In situ synthesis of porous Pt-Pd bimetallic structures for sweat gluco.e biosensing using dynamic hydrogen bubble template method

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Rare Metals 2024年第7期43卷 3408-3414页

作者： Yi-Wen Guo Qian-Hui Wei Fei Wei Hao Liu Hong-Bin Zhao Dong Wang Hai-Ling Tu State Key Laboratory of advanced Materials for Smart Sensing China GRINM Group Co.Ltd. Department of advanced Electronic Materials GRIMAT Engineering Institute Co.Ltd. General Research Institute for Nonferrous Metals GRINM (Guangdong) Institute for advanced Materials and Technology School of Chemical Engineering Northeast Electric Power University

For the practical application of sweat gluco.e biosensors,it is crucial to develop a method for modifying the working electrode with noble metals that ensures strong *** this study,we synthesized porous Pt-Pd bimetall... 详细信息

关键词： Hydrogen

High-repetition-rate and high-power efficient pico.eco.d thin-disk regenerative amplifier

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High Power Laser Science and Engineering 2024年第2期12卷 16-23页

作者： Sizhi Xu Yubo Gao Xing Liu Yewang Chen Deqin Ouyang Junqing Zhao Minqiu Liu Xu Wu Chunyu Guo Cangtao Zhou Qitao Lue Shuangchen Ruan Key Laboratory of advanced Optical Precision manufacturing Technology of Guangdong Higher Education Institutes Sino-German College of Intelligent ManufacturingShenzhen Technology UniversityShenzhenChina Han’s Laser Technology Industry Group co. Ltd.ShenzhenChina Shenzhen Key Laboratory of Laser Engineering College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhenChina Shenzhen Key Laboratory of Ultraintense Laser and advanced Material Technology College of Engineering PhysicsShenzhen Technology UniversityShenzhenChina

We present an effective approach to realize a highly efficient,high-power and chirped pulse amplification-free ultrafast ytterbium-doped yttrium aluminum garnet thin-disk regenerative amplifier pumped by a zero-phonon line 969 nm laser *** amplifier delivers an output power exceeding 154 W at a pulse repetition rate of 1 MHz with custom-designed 48 pump *** exceptional thermal management on the thin disk through high-quality bonding,efficient heat dissipation and a fully locked spectrum co.lectively co.tributes to achieving a remarkable optical-to-optical efficiency of 61%and a near-diffraction-limit beam quality with an M2 factor of *** the best of our knowledge,this represents the highest co.version efficiency reported in ultrafast thin-disk regenerative ***,the amplifier operates at room temperature and exhibits exceptional stability,with root mean square stability of less than 0.33%.This study significantly represents advances in the field of laser amplification systems,particularly in terms of efficiency and average *** advantageous co.bination of high efficiency and diffraction limitation positions the thin-disk regenerative amplifier as a promising solution for a wide range of scientific and industrial applications.

关键词： high efficiency high power pico.eco.d laser regenerative amplifier thin-disk laser

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 ion-exchangeable 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

Effect of post rolling stress on phase transformation behavior of microalloyed dual phase steel

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Journal of Iron and Steel Research(International) 2024年第3期31卷 688-699页

作者： Wen-quan Sun Sheng-yi Yong Tie-heng Yuan Ting-song Yang An-rui He Chao Liu Rui-chun Guo National Engineering Research Center for advanced Rolling and Intelligent manufacturing University of Science and Technology BeijingBeijing 100083China

The slow phase transformation of microalloyed dual phase steel makes the nonuniform stress and temperature fields during the post rolling co.ling process have a significant impact on the phase transformation *** the relatively slow phase transformation of DP780 steel within the microalloyed dual phase steel series,the influence of stress on the phase transformation behavior of DP780 steel was *** quantify the nonuniform thermal and stress co.ditions in the steel co.l,a thermo-mechanical co.pled finite element model of the hot-rolled strip co.ling process was *** on the simulation data,DP780 steel was chosen as the research material,and Gleeble 3500 thermal simulation equipment was used for experimental *** thermal expansion curves were analyzed through regression to establish the dynamic model of DP780 steel phase transformation under ***,metallographic analysis was co.ducted to determine phase transformation type and grain size of DP780 *** results co.firmed that the stress promotes the occurrence of semi-diffusion-type bainite ***,an appropriate level of stress facilitates the growth of bainitic grains,while the increased stress inhibits the growth of ferritic grains.

关键词： Microalloyed dual phase steel Stress Bainitic transformation Grain Finite element method