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Effect of cerium on microstructure,texture and properties of ultrahigh-purity copper

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Journal of Rare Earths 2024年第1期42卷 220-227,I0008页

作者： Yunxiao Hua Haitao Liu Kexing Song Jiangwei Wang Yin'gang guo Jing Tian Huiwen guo Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology School of Materials Science and EngineeringHenan University of Science and TechnologyLuoyang471023China Henan Academy of Sciences Zhengzhou450000China Center of Electron Microscopy and State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou310027China Henan Zhongyuan Gold Smelter Co. Ltd.Sanmenxia472100China Chinalco Luoyang Copper Processing Co. Ltd.Luoyang471039China

The effects of Ce addition(310 ppm and 1500 ppm)on the microstructure,texture and properties of ultrahigh-purity copper(99.99999%)were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM)and electron backscattered diffraction(EBSD)analyses,combined with the microhardness and conductivity *** the microstructure of the as-cast and as-extruded samples,the addition of Ce refines the grain size of the ultrahigh-purity copper and the refinement effect of 310Ce alloy is greater than that of 1500Ce *** is due to the stronger compone nt supercooling and the accele rated recrystallization caused by lower Ce co *** addition,Ce can react with Cu to form the Cu-Ce eutectic phases,which are deformable during the hot ***,the added Ce can weaken the texture,showing a variation of brass recrystallization(BR),rotated cube,copper and S texture components,which depends on the recrystallization,the particle stimulated nucleation(PSN)as well as the stacking fault energy(SFE).Most remarkably,the introduction of Ce enhances the hardness of the ultrahigh-purity copper without obviously reducing its *** major{111}orientations and the stress distributions are responsible for such a superior conductivity of the Ce-containing alloys.

关键词： Ce addition Grain refinement Texture Conductivity Ultrahigh-purity copper Rare earths

Lead-free metal halide scintillator materials for imaging applications

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Science China(Information Sciences) 2024年第8期67卷 85-101页

作者： Junzhe LIN Dan guo Tianrui ZHAI Department of Physics and Optoelectronic Engineering Beijing University of Technology

High-energy radiation detection and imaging technology has significant applications in highenergy physics research, medical imaging, and industrial monitoring. Lead-free metal halides exhibit exceptional potential for conducting indirect detection of high-energy radiation due to their characteristics of low toxicity, strong stability, high light yield, and large Stokes shift. This paper reviews the most recent advances in lead-free metal halide scintillator materials for X-ray imaging. Subsequently, it lists the most important parameters of scintillator performance and introduces the production procedures for single crystal, powder,and nanocrystal scintillators. Furthermore, it discusses the manufacturing of scintillator films with improved performance, focusing on large-area flexible scintillator films and the coupling with microstructures. Finally,it discusses current challenges and opportunities for enhancing X-ray imaging using lead-free metal halide scintillator materials.

关键词： film imaging lead-free metal halide luminescence scintillators

基于密度分布特征的深度神经网络模型诊断COVID-19的价值

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中国医学物理学杂志 2022年第8期39卷 972-979页

作者：李文韩冬郭佑民任转勤田宏哲宝鸡市中心医院医学影像科陕西宝鸡721008 陕西中医药大学附属医院医学影像科陕西咸阳712021 西安交通大学第一附属医院医学影像科陕西西安710061

目的:评价基于密度分布特征(CDD)的深度神经网络(DNN)模型对新型冠状病毒肺炎(COVID-19)的诊断价值。方法:收集42例COVID-19病例和43例非COVID-19肺炎病例。将所有患者的211份胸部CT图像分为训练集(n=128)和验证集(n=83)。参考北美放射... 详细信息

目的:评价基于密度分布特征(CDD)的深度神经网络(DNN)模型对新型冠状病毒肺炎(COVID-19)的诊断价值。方法:收集42例COVID-19病例和43例非COVID-19肺炎病例。将所有患者的211份胸部CT图像分为训练集(n=128)和验证集(n=83)。参考北美放射学会发布的COVID-19相关性肺炎的CT结构化报告,构建基于CT影像特征的DNN模型(DNN-CTIF)。根据胸部CT图像上肺炎CDD建立DNN-CDD模型。采用ROC曲线分析和决策曲线分析对两种模型进行评价。结果:DNN-CTIF模型的AUC在训练集为0.927,在验证集为0.829。DNN-CDD模型的AUC在训练集为0.965,在验证集为0.929。DNN-CDD模型在验证集的AUC高于DNN-CTIF模型(P=0.047)。决策曲线分析表明在0.04~1.00概率阈值范围内,DNN-CDD模型相比DNN-CTIF模型使患者的净获益更高。结论:DNN-CTIF和DNN-CDD模型对COVID-19均具有较好的诊断性能,其中DNN-CDD模型优于DNN-CTIF模型。

关键词：新型冠状病毒肺炎密度分布特征 CT图像特征深度神经网络

Preparation of a zeolite-palladium composite membrane for hydrogen separation: Influence of zeolite film on membrane stability

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CHINESE JOURNAL OF CHEMICAL ENGINEERING 2024年第8期72卷 44-52页

作者： Wu, Hongmei Liu, Xinyu guo, Yu Liaoning Univ Technol Sch Chem & Environm Engn Jinzhou 121001 Peoples R China

With the development of hydrogen energy, palladium-based membranes have been widely used in hydrogen separation and purification. However, the poor chemical stability of palladium composite membranes limits their commercial applications. In this study, a zeolite-palladium composite membrane with a sandwich-like structure was obtained by using a TS-1 zeolite film grown on the surface of palladium membrane. The membrane microstructure was characterized by SEM and EDX. The effects of the TS-1 film on the hydrogen permeability and stability of palladium composite membrane were investigated in details. Benefited from the protection of the TS-1 zeolite film, the stability of palladium composite membrane was enhanced. The results indicate that the TS-1-Pd composite membrane was stable after eight cycles of the temperature exchange cycles between 773 K and 623 K. Especially, the loss of hydrogen permeance for TS-1-Pd composite membrane was much smaller than that of the pure palladium membrane when the membrane was tested in the presence of C 3 H 6 atmosphere. It indicated that the TS-1-Pd composite membrane had better chemical stability in comparison with pure palladium membrane, owing to its sandwich-like structure. This work provides an efficient way for the deposition of zeolite film on palladium membrane to enhance the membrane stability. (c) 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

关键词： Palladium membrane Zeolite film Hydrogen separation Stability ALUMINA TUBE PD PERMEATION HYDROCARBONS FABRICATION SOLUBILITY RESISTANT MIXTURES LAYER

Regional climate response to global warming in the source region of the Yellow River and its impact on runoff

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Science China Earth Sciences 2024年第3期67卷 843-855页

作者： Yiran ZHANG Degang ZHOU Xiaofeng guo Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The source region of the Yellow River has experienced obvious climate and discharge changes in recent decades due to global warming, which largely affects the water resources and ecological and environmental security in the Yellow River basin. This study analyzed the changes in runoff and several climate factors in the source region of the Yellow River based on the observed discharges at the Tangnag hydrological station, routine meteorological data from China Meteorological Administration(CMA) stations within and near this source region, and several evaporation datasets. The results indicate that the runoff in the source region was relatively abundant from 1960 to 1989 and then declined sharply afterward. It recovered slightly after 2005 but was still below normal—10% less than that during 1960–1989. Similarly, the precipitation amounts in the source region were relatively low in the 1990s, but they increased significantly after 2003, with an average increase of 31.4 mm or 6% more when compared to that in 1960–1989. In addition, the temperatures in the source region continued to rise from 1960 to 2017, and the evaporation levels also showed an upward trend after 1990. The influences of the spatial and temporal variations in climatic factors on runoff in the source region were then further analyzed. The results indicate that the decreases in precipitation and the number of days of heavy rainfall in the source region from 1990 to 2002 were important reasons for the lower runoff during this period. After 2003, the precipitation in the southeastern part of the source region, which is a key area for runoff generation,increased only to a limited extent, but the evaporation in the entire source region generally increased with increasing temperature,which might have led to the low capacity for actual runoff production in each subbasin and persistent low runoff in the source region. Therefore, such a climate response to global warming in the source region might be unfavorabl

关键词： The source region of the Yellow River Climate response Runoff variation Evaporation Precipitation

Body size induced changes in metabolic carbon of soil nematodes under N deposition and precipitation regime change in a temperate grassland

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Ecological Processes 2024年第1期13卷 120-131页

作者： Shuyan Cui Xiaomei Mo guo Zheng College of Life Science Shenyang Normal University

Background Global climate change has resulted in precipitation regimes exhibiting an increasing trend in rainfall intensity but a reduction in its frequency. Nitrogen(N) deposition is a crucial component of the global N cycling. Nematode body size is a trait that responds to climate change and is used as a standard trait-based indicator in soil community analysis. Variations in body size influence metabolic carbon(C). We examined the ways by which body size and metabolic C of nematodes respond to changing precipitation regimes and how N deposition regulates these responses by an 8-year manipulative *** Nematode body size was indicated by the community-weighted mean(CWM) mass. We quantified C metabolism components of soil nematodes including production C, respiration C, and corresponding C use efficiency(CUE) under different precipitation intensities and N addition in a semi-arid steppe on the Mongolian Plateau. The Mantel test was used to determine the correlations between CWM, CUE and environmental factors. The partial least squares path modeling(PLS-PM) was conducted to quantify direct or indirect contributions among latent *** We found that heavy precipitation intensity increased the CWM mass of total nematodes and omnivorespredators without N addition. N addition decreased CWM mass of bacterivores across all the precipitation intensity treatments. Stronger precipitation intensities might be favorable for nematode production and respiration C. Variations in the nematode CWM mass drove the CUE to change with N *** Our findings provide new insights into the mechanisms underlying nematode body size and C metabolism, and highlight that explorative studies, such as manipulative experiments, are needed to identify traits underlying size-related effects and to investigate how they affect CUE of nematodes. These efforts may increase our understanding of how changes in precipitation regimes and N deposition may alter soil nema

关键词： Community-weighted mean Metabolic footprint Nitrogen addition Precipitation intensity

Corrosion behavior of Gd_(2)Zr_(2)O_(7)thermal barrier coatings under Fe-containing environmental sediment attack

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Journal of Advanced Ceramics 2024年第4期13卷 447-462页

作者： Lei guo Yanyan Li Kai Yan School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin 300072China Key Laboratory of Special Equipment Safety and Energy-saving for State Market Regulation China Special Equipment Inspection&Research InstituteBeijing 100029China

Environmental sediments mainly consisting of CaO–MgO–Al_(2)O_(3)–SiO_(2)(CMAS)corrosion are a serious threat to thermal barrier coatings(TBCs),in which Fe element is usually ***_(2)Zr_(2)O_(7)TBCs are famous for their excellent CMAS *** this study,the characteristics of Fe-containing environmental sediments(CMAS-Fe)and their corrosiveness to Gd_(2)Zr_(2)O_(7)coatings were *** types of CMAS-Fe glass with different Fe contents were *** melting points were measured to be 1322–1344℃,and the high-temperature viscosity showed a decreasing trend with increasing Fe *** corrosion behavior of four types of CMAS-Fe to Gd_(2)Zr_(2)O_(7)coatings at 1350℃was *** the initial corrosion stage(0.1 h),anorthite was precipitated in CMAS-Fe with a high Ca:Si ratio,while Fe-garnet was formed in the melt with the highest Fe *** the corrosion time resulted in the formation of a reaction layer,which exhibited an interpenetrating network composed of Gd-oxyapatite,ZrO_(2),and residual *** spinel was precipitated within the reaction *** 1 h or even longer time,the reaction layers tended to be stable and compact,which had comparable hardness and fracture toughness to those of Gd_(2)Zr_(2)O_(7)*** the cyclic CMAS-Fe attack,the residual CMAS-Fe in the interpenetrating network provided a pathway for the redeposited CMAS-Fe infiltration,resulting in the continuous growth of the reaction *** a result,the Gd_(2)Zr_(2)O_(7)coatings had a large consumption in the thickness,degrading the coating ***,the Gd_(2)Zr_(2)O_(7)coatings exhibit unsatisfactory corrosion resistance to CMAS-Fe attack.

关键词： thermal barrier coatings(TBCs) Gd_(2)Zr_(2)O_(7) Fe-containing CaO-MgO-Al2O3-SiO_(2)(CMAS) corrosion resistance reaction layer

Multifunction-oriented high-mobility polymer semiconductors

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National Science Review 2024年第3期11卷 16-19页

作者： Mingliang Zhu Yunlong guo Yunqi Liu Beijing National Laboratory for Molecular Sciences Organic Solids Laboratory Institute of Chemistry Chinese Academy of Sciences School of Chemical Sciences University of Chinese Academy of Sciences

The discovery of conductive polyacetylene has initiated interdisciplinary research into condensed matter physics and synthetic chemistry in organic electronics. Unlike their inorganic and small-molecule counterparts, polymer semiconductors possess the inherent advantages of facile solution processing,large-area manufacturing, excellent mechanical strength and intrinsic flexibility.

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Revealing the role of calcium ion intercalation of hydrated vanadium oxides for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第8期95卷 9-19,I0001页

作者： Tao Zhou Xuan Du guo Gao Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education School of Sensing Science and EngineeringSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Exploring suitable high-capacity V_(2)O_(5)-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn^(2+)diffusion kinetics has severely limited the feasibility of such *** this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca^(2+)or Ba^(2+)into hydrated vanadium *** the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g^(-1)discharge specific capacity at 0.1 A g^(-1).Moreover,the remarkable energy density of 370.07 Wh kg^(-1)and favorable cycling stability yard outperform BaVO,pure V_(2)O_(5),and many reported cathodes of similar ionic intercalation *** addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn^(2+)diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical performance of ***,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn^(2+)insertion/extraction and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery *** work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.

关键词： Aqueous zinc ion batteries Cathode materials Ion pre-intercalation Vanadium oxides Energy storage mechanism