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Structural and magnetic properties of micropolycrystalline cobalt thin films fabricated by direct current magnetron sputtering

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 384-394页

作者： Kerui song Zhou li Mei fang Zhu Xiao Qian Lei School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Hunan Key Laboratory of Super-Microstructure and Ultrafast Process School of Physics and electronicsCentral South UniversityChangsha 410083China Key Laboratory of Non-Ferrous Metal Materials Science and Engineering Ministry of EducationChangsha 410083China

Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were *** the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore ***,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy *** the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect ***-pondingly,a quantitative model for the coercivity of Co thin films was *** polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.

关键词： cobalt thin film magnetron sputtering microstructure electromagnetic properties

Unraveling the atomic interdiffusion mechanism of NiFe_(2_)O_(4)oxygen carriers during chemical looping CO_(2)conversion

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Carbon Energy 2024年第8期6卷 105-121页

作者： Da song Yan lin Shiwen fang Yang li Kun Zhao Xinfei Chen Zhen Huang fang He Zengli Zhao Hongyu Huang Fanxing li Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhouChina School of Energy Science and Engineering University of Science and Technology of ChinaHefeiChina College of Mechanical and Electrical Engineering Zhongkai University of Agriculture and EngineeringGuangzhouChina College of Chemistry and Bioengineering Guilin University of TechnologyGuilinChina North Carolina State University RaleighNorth CarolinaUSA

By employing metal oxides as oxygen carriers,chemical looping demonstrates its effectiveness in transferring oxygen between reduction and oxidation environments to partially oxidize fuels into syngas and convert CO_(2)into ***,NiFe_(2_)O_(4)oxygen carriers have demonstrated remarkable efficiency in chemical looping CO_(2)***,the intricate process of atomic migration and evolution within the internal structure of bimetallic oxygen carriers during continuous high‐temperature redox cycling remains ***,the lack of a fundamental understanding of the complex ionic migration and oxygen transfer associated with energy conversion processes hampers the design of high‐performance oxygen ***,in this study,we employed in situ characterization techniques and theoretical calculations to investigate the ion migration behavior and structural evolution in the bulk of NiFe_(2_)O_(4)oxygen carriers during H2 reduction and CO_(2)/lab air oxidation *** discovered that during the H2 reduction step,lattice oxygen rapidly migrates to vacancy layers to replenish consumed active oxygen species,while Ni leaches from the material and migrates to the *** the CO_(2)splitting step,Ni migrates toward the core of the bimetallic oxygen carrier,forming Fe–Ni *** the air oxidation step,Fe–Ni migrates outward,creating a hollow structure owing to the Kirkendall effect triggered by the swift transfer of lattice *** metal atom migration paths depend on the oxygen transfer *** discoveries highlight the significance of regulating the release–recovery rate of lattice oxygen to uphold the structures and reactivity of oxygen *** work offers a comprehensive understanding of the oxidation/reduction‐driven atomic interdiffusion behavior of bimetallic oxygen carriers.

关键词： chemical looping CO_(2)splitting density functional theory in situ characterization ionic migration

First Record of Cyclocarya from the Early Oligocene Qaidam Basin,North Tibet:Implications for the Paleogeography and Paleoecology

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Journal of Earth Science 2024年第1期35卷 201-211页

作者： Yafei Hou Bowen song Xiangchuan li fang Han Xu Zhang Kexin Zhang Institute of Geological Survey China University of GeosciencesWuhan 430074China Faculty of Materials Science and Chemistry China University of GeosciencesWuhan 430074China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China College of Earth Sciences and Resources&Key Laboratory of Western Mineral Resources and Geological Engineering of the Ministry of Education Chang'an UniversityXi'an 710054China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China School of Earth Sciences East China University of TechnologyNanchang 330013China

As the largest intermontane basin in the northeastern Tibetan Plateau(TP),the Qaidam Basin provides unique insight into paleoclimatic change and its relationship with global change and uplift on the *** this study,based on morphological comparison,fossil fruit of Cyclocarya from the Early Oligocene Shangganchaigou Formation in the Qaidam Basin is assigned as Cyclocarya *** discovery of Cyclocarya *** demonstrates the occurrence of Cyclocarya in the Oligocene sediment in Qaidam *** is the first record of Cyclocarya fossil of Early Oligocene Age in China and indicates that Cyclocarya has existed on the northeastern TP since at least the Early *** living analogues of the current fossil now lives in sub-tropical China,where the East Asian Monsoon is *** the new fossils and previously reported fossil remains of plants and fishes,it can be inferred that the Early Oligocene Qaidam Basin was primarily influenced by westerly circulation and had a relatively warm and humid climate,which was in sharp contrast to the present-day climate in Qaidam Basin.

关键词： biostratigraphy climate change winged-fruit fossil Qaidam Basin Early Oligocene paleoclimate paleogeography

Quasi-two dimensional Ruddlesden−Popper halide perovskites for laser applications

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Frontiers of physics 2024年第2期19卷 53-71页

作者： Kun Chen Qianpeng Zhang Yin liang Jiepeng song Chun li Shi Chen fang li Qing Zhang School of Mechanical and Electrical Engineering Wuhan Institute of TechnologyWuhan 430205China School of Materials Science and Engineering Peking UniversityBeijing 100871China Institute of Applied Physics and Materials Engineering Macao UniversityMacao 999078China

Quasi-two-dimensional(2D)Ruddlesden‒Popper(RP)halide perovskites,as a kind of emerged two-dimensional layered materials,have recently achieved great attentions in lasing materials field owing to their large exciton binding energy,high emission yield,large optical gain,and wide-range tuning of optical *** review will introduce research progresses of RP halide perovskites for lasing applications in aspects of materials,photophysics,and devices with emphasis on emission and lasing properties tailored by the molecular composition and *** materials,structures and fabrications are introduced in the first ***,the optical transitions and amplified spontaneous emission properties are discussed from the aspects of electronic structure,exciton,gain dynamics,and interface ***,the research progresses on lasing devices are summarized and several types of lasers including VCSEL,DFB lasers,microlasers,random lasers,plasmonic lasers,and polariton lasers are *** last,the challenges and perspectives would be provided.

关键词： two-dimensional materials metal halide perovskite Ruddlesden−Popper halide perovskites lasing emission

Progress in improving thermodynamics and kinetics of new hydrogen storage materials

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Frontiers of physics 2011年第2期6卷 151-161页

作者： li-fang song Chun-hong JIANG Shu-sheng liU Cheng-li JIAO Xiao-liang SI Shuang WANG Fen li Jian ZHANG li-xian SUN Fen XU Feng-lei HUANG Materials and Thermochemistrg Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China Faculty of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 China Beijing Institute of Technology State Key Laboratory of Explosion Science ＆ Technology Beijing 100081 China

Hydrogen storage material has been much developed recently because of its potential for proton exchange membrane （PEM） fuel cell applications. A successful solid-state reversible storage material should meet the requirements of high storage capacity, suitable thermodynamic properties, and fast adsorption and desorption kinetics. Complex hydrides, including boron hydride and alanate, ammonia borane, metal organic frameworks （MOFs）, covalent organic frameworks （COFs） and zeolitic imidazolate frameworks （ZIFs）, are remarkable hydrogen storage materials because of their advantages of high energy density and safety. This feature article focuses mainly on the thermodynamics and kinetics of these hydrogen storage materials in the past few years.

关键词： ammonia borane hydrogen storage materials hydrides kinetics metal organic frameworks thermodynamics

Effect of Y_2Ba_4CuWO_y Addition on the Properties of Single Domain YBCO Superconductors by TSIG Technique

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稀有金属材料与工程 2011年第S3期40卷 362-364页

作者： Wan Feng, Yang Wanmin, li Guozheng, song fang, Gao Ping, liang Wei Shaanxi Normal University, Xi’an 710062, China Shaanxi Normal Univ Dept Phys Xian 710062 Peoples R China

Top seeded infiltration and growth technique (TSIG) is an effective method for the preparation of high quality large YBa2Cu3O7-x (YBCO) bulk superconductors. In this paper, single domain YBCO bulk superconductors, with different Y2Ba4CuWOy (YW2411) additions, have been fabricated by TSIG process. the solid phase pellet is made of a mixture of Y2BaCuO5(Y211) + xwt% YW2411 powders, x=0, 1, 3, 5, 7, 9. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 23.05 to 33.6 N with the increasing of YW2411 addition from 0 to 5wt%, and decreasing from 33.6 to 21.59 N with the increasing of YW2411 addition from 5 to 9wt%,the largest levitation force is obtained when the YW2411 content is about 5wt%. This is very important for us to fabricate high quality YBCO bulk superconductors.

关键词： single domain YBCO bulk top seeded infiltration and growth technique Y2Ba4CuWOy addition levitation force

The Extended Hybrid Carrier-Based Multiple Access Technology for High Mobility Scenarios

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China Communications 2024年第1期21卷 53-68页

作者： Ge song Xiaojie fang Xuejun Sha School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China

The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering *** this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless *** employing the EHC modulation,a power layered multiplexing framework is realized,which exhibits enhanced interference suppression capability owing to the more uniform energy distribution *** implementation method and advantage mechanism are explicated respectively for the uplink and downlink,and the performance analysis under varying channel conditions is *** addition,considering the connectivity demand,we explore the non-orthogonal multiple access(NOMA)method of the EHC system and develop the EHC sparse code multiple access *** proposed scheme melds the energy spread superiority of EHC with the access capacity of NOMA,facilitating superior support for massive connectivity in high mobility *** results have verified the feasibility and advantages of the proposed *** with existing HC multiple access schemes,the proposed scheme exhibits robust bit error rate performance and can better guarantee multiple access performance in complex scenarios of nextgeneration communications.

关键词： extended hybrid carrier system high mo-Received:Jun.09,2023 Revised:Nov.20,2023 Editor:Yuanwei liu bility communications multiple access

A systematic review of the inequality of health burdens related to climate change

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 137-153页

作者： Xinke song Shihui Zhang Hai Huang Qun Ding fang Guo Yaxin Zhang Jin li Mingyu li Wenjia Cai Can Wang State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Department of Earth System Science Tsinghua UniversityBeijing100084China

Climate change significantly impacts human health,exacerbating existing health inequalities and creating new *** study addresses the lack of systematic review in this area by analyzing 2440 publications,focusing on four key terms:health,disparities,environmental factors,and climate *** inclusion criteria limited the selection to English-language,peer-reviewed articles related to climate health hazards,ensuring the relevance and rigor of the synthesized *** process synthesized 65 relevant *** investigation revealed that recent research,predominantly from developed countries,has broadened its scope beyond temperature-related impacts to encompass diverse climate hazards,including droughts,extreme weather,floods,mental health issues,and the intersecting effects of Coronavirus Disease *** has highlighted exposure as the most studied element in the causal chain of climate change-related health inequalities,followed by adaptive capability and inherent *** most significant vulnerabilities were observed among populations with low socioeconomic status,ethnic minorities,and *** study further reveals research biases and methodological limitations,such as the paucity of attention to underdeveloped regions,a narrow focus on non-temperature-related hazards,challenges in attributing climate change effects,and a deficit of large-scale empirical *** findings call for more innovative research approaches and a holistic integration of physical,socio-political,and economic dimensions to enrich climate-health discourse and inform equitable policy-making.

关键词： Climate change Health impact Human well-being Inequality Vulnerability

AdaPIP: Adaptive picture-in-picture guidance for 360° film watching

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Computational Visual Media 2024年第3期10卷 487-503页

作者： Yi-Xiao li Guan Luo Yi-Ke Xu Yu He fang-Lue Zhang song-Hai Zhang Department of Computer Science and Technology Tsinghua UniversityBeijingChinaand Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijingChina Key Laboratory of Space Utilization Technology and Engineering Center for Space UtilizationChinese Academy of SciencesBeijingChina Victoria University of Wellington WellingtonNew Zealand

360°videos enable viewers to watch freely from different directions but inevitably prevent them from perceiving all the helpful *** mitigate this problem,picture-in-picture(PIP)guidance was proposed using preview windows to show regions of interest(ROIs)outside the current view *** identify several drawbacks of this representation and propose a new method for 360° film watching called *** enhances traditional PIP by adaptively arranging preview windows with changeable view ranges and *** addition,AdaPIP incorporates the advantage of arrow-based guidance by presenting circular windows with arrows attached to them to help users locate the corresponding ROIs more *** also adapted AdaPIP and Outside-In to HMD-based immersive virtual reality environments to demonstrate the usability of PIP-guided approaches beyond 2D *** user experiments on 2D screens,as well as in VR environments,indicate that AdaPIP is superior to alternative methods in terms of visual experiences while maintaining a comparable degree of immersion.

关键词： 360°videos picture-in-picture(PIP) virtual reality(VR) visual guidance