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Three-stage niobium mineralization at Bayan Obo, China

National Science Review 2024年第4期11卷 102-110页

作者： Yan Yu yang li Yu liu Xiao-Xiao ling li-Guang Wu li yang Lan yang Bo yang Yong-Gang Zhao Xian-Hua li State Key Laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Science University of Chinese Academy of Sciences Ministry of Education Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University Mining Research Institute Baotou Iron and Steel(Group) Co.LTD State Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization

The Chinese Bayan Obo deposit is a world-class rare earth element(REE) deposit with considerable niobium(Nb) and iron(Fe) resources. A complete genetic understanding on all metals is fundamental for establishing genetic models at Bayan Obo. With extensive research being focused on REE enrichment, the timing and controls of Nb enrichment remain unresolved at Bayan Obo, which is mainly due to the challenges in dating, i.e. multistage thermal events, fine-grained minerals with complex textures and the rare occurrence of uranium-enriched minerals with mature dating methods. Based on robust geological and petrographic frameworks, here we conducted ion probe uranium-lead(U-Pb) dating of ferrocolumbite to unravel the timing, hence the genesis of Nb mineralization. Three types of hydrothermal ferrocolumbites—key Nb-bearing minerals—are identified based on their textures and mineral assemblages. They yield U-Pb ages of 1312 ± 47 Ma(n = 99), 438 ± 7 Ma(n = 93), and 268 ± 5 Ma(n = 19), respectively. In line with deposit geology, we tentatively link the first, second and third stage Nb mineralization to Mesoproterozoic carbonatite magmatism, ubiquitous early Paleozoic hydrothermal activity, and Permian granitic magmatism, respectively. While quantifying the contribution of metal endowment from each stage requires further investigation, our new dates highlight that multi-stage mineralization is critical for Nb enrichment at Bayan Obo, which may also have implications for the enrichment mechanism of Nb in REE deposits in general.

关键词： niobium mineralization U-Pb dating ferrocolumbite Bayan Obo

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Side Information-Based Stealthy False Data Injection Attacks Against Multi-Sensor Remote Estimation

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1054-1056页

作者： Haibin Guo Zhong-Hua Pang chao li the Key Laboratory of Fieldbus Technology and Automation of Beijing North China University of TechnologyBeijing 100144China

Dear Editor,This letter investigates a novel stealthy false data injection(FDI)attack scheme based on side information to deteriorate the multi-sensor estimation performance of cyber-physical systems(CPSs).Compared with most existing works depending on the full system knowledge,this attack scheme is only related to attackers'sensor and physical process *** design principle of the attack signal is derived to diverge the system estimation ***,it is proven that the proposed attack scheme can successfully bypass the residual-based ***,all theoretical results are verified by numerical simulation.

关键词： estimation scheme system

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β-C(sp^(3))−H chlorination of amide derivatives via photoinduced copper charge transfer catalysis

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Chinese Chemical Letters 2024年第2期35卷 361-365页

作者： Yuhang He chao Tian Guanghui An Guangming li Key Laboratory of Functional Inorganic Material Chemistry (MOE) School of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080China

An atom economicβ-C(sp^(3))−H chlorination of amide derivatives has been *** mild protocol employs CuCl_(2) instead of palladium catalysts with atom-economic HCl as chlorine sources and enables the late-stage functionalization of medicine *** studies suggest a plausible visible light triggered ligand-to-metal charge transfer(LMCT)/1,4-hydrogen atom transfer(HAT)cascade.

关键词： Photoinduced copper catalysis ligand-to-metal charge transfer 1,4-Hydrogen atom transfer β-Halogenated amide Late-stage functionalization

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FAST Observations of Four Comets to Search for the Molecular line Emissions between 1.0 and 1.5 GHz Frequencies

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Research in Astronomy and Astrophysics 2024年第10期24卷 130-140页

作者： Long-Fei Chen chao-Wei Tsai Jian-yang li Bin yang Di li Yan Duan Chih-Hao Hsia Zhichen Pan Lei Qian Donghui Quan Xue-Jian Jiang Xiaohu li Ruining Zhao Pei Zuo School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550025China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guiyang 550025China Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311100China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China Núcleo de Astronomía Facultad de Ingenieríay CienciasUniversidad Diego PortalesChile Department of Astronomy College of Physics and Electronic EngineeringQilu Normal UniversityJinan 250200China Department of Electronic and Optical Engineering Space Engineering UniversityBeijing 101416China Laboratory for Space Research Faculty of ScienceThe University of Hong KongHong Kong(SAR)China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

We used the Five-hundred-meter Aperture Spherical radio Telescope(FAST)to search for the molecular emissions in the L-band between 1.0 and 1.5 GHz toward four comets,C/2020 F3(NEOWISE),C/2020 R4(ATLAS),C/2021 A1(Leonard),and 67P/Churyumov-Gerasimenko during or after their perihelion *** of molecular transition lines fall in this low-frequency range,many attributed to complex organic or prebiotic *** conducted a blind search for the possible molecular lines in this frequency range in those comets and could not identify clear signals of molecular emissions in the *** several molecules have been detected at high frequencies of greater than100 GHz in comets,our results confirm that it is challenging to detect molecular transitions in the L-band frequency *** non-detection of L-band molecular lines in the cometary environment could rule out the possibility of unusually strong lines,which could be caused by the masers or non-LTE *** the line strengths are predicted to be weak,for FAST,using the ultra-wide bandwidth receiver and improving the radio frequency interference environments would enhance the detectability of those molecular transitions at low frequencies in the future.

关键词： astrochemistry ISM:molecules comets:general line:identification

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Paired quasi-periodic pulsations of hard X-ray emission in a solar flare

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Science China(Physics,Mechanics & Astronomy) 2023年第5期66卷 195-206页

作者： Hai-Sheng Zhao Dong li Shao-lin Xiong Yan-Qiu Zhang yang Su Wei Chen Yi Zhao Xiao-Bo li Jia-Cong liu Wen-Xi Peng Rui Qiao Xin-Qiao li Xiang-yang Wen li-Ming Song Shi-Jie Zheng Xin-Ying Song Xiao-Yun Zhao Yue Huang Shuang-Nan Zhang Shuo Xiao Ce Cai Zheng-Hua An Can Chen Gang Chen Wei Chen Yan-Qi Du Min Gao Ke Gong Dong-Ya Guo Zhi-Wei Guo Jian-Jian He Bin li chao li chao-yang li Gang li Jian-Hui li Lu li Qing-Xin li Yan-Guo li Jing liang Xiao-Hua liang Jin-Yuan liao Xiao-Jing liu Ya-Qing liu Qi Luo Xiang Ma Bin Meng Ge Ou Dong-li Shi Jing-Yan Shi Gong-Xing Sun Xi-Lei Sun You-li Tuo Chen-Wei Wang Hui Wang Jin Wang Jin-Zhou Wang Ping Wang Wen-Shuai Wang Hong Wu Sheng-Lun Xie Yan-Bing Xu Yu-Peng Xu Wang-Chen Xue Sheng yang Min Yao Jian-Ying Ye Qi-Bin Yi chao-Yue Zhang Da-li Zhang Fan Zhang Fei Zhang Hong-Mei Zhang Kai Zhang Peng Zhang Xiao-Lu Zhang Zhen Zhang Guo-Ying Zhao Shi-Yi Zhao chao Zheng Xing Zhou Yue Zhu Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China University of Chinese Academy of Sciences Beijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China School of Computing and Artificial Intelligence Southwest Jiaotong UniversityChengdu 611756China Physics and Space Science College China West Normal UniversityNanchong 637002China Key Laboratory of Stellar and Interstellar Physics and Department of Physics Xiangtan UniversityXiangtan 411105China Institute of Astrophysics Central China Normal UniversityWuhan 430079China School of Physics Changchun University of Science and TechnologyChangchun 130022China College of Physics and Engineering Qufu Normal UniversityQufu 273165China College of Physics Sciences&Technology Hebei UniversityBaoding 071002China

We investigate high time resolution data obtained by the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)during the flare event on 2022 April 21 at 01:52 *** subpeaks with durations of 4-6 s have been detected in the hard X-ray precursor phase,and the key feature is that they appear in pairs and seem like double-peak *** subpeaks are rarely observed in hard X-ray band and confirmed by the microwave obtained by Nobeyama Radio Polarimeters(NoRP)and Radio Solar Telescope Network(RSTN).While an exponential function can describe the continuum component of the time profile from the precursor to part of the impulsive *** periods of quasi-periodic pulsations(QPPs)are detected to be about 7.3 and 12.8 s for the precursor and impulsive phase,respectively,with at least 95%confidence *** paired QPPs are assumed to be double-peak QPPs and then the scenario of current loop coalescence model is found to be in good agreement with our *** precursor phase can be interpreted as the oscillating coalescence of two islands,while the impulsive phase can be interpreted as more islands to coalesce one by one to form larger islands.

关键词： solar flare QPPs loop coalescence circular-ribbon flare

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Pd cluster decorated free standing flexible cathode for high performance li-oxygen batteries

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Nano Research 2024年第4期17卷 2678-2686页

作者： liang Guo Guoliang Zhang Ruonan yang Dongmei Zhang Xiuqi Zhang Han Yu Xia li Feng Dang Key Laboratory for liquid-Solid Structure Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

As a promising candidate for the next generation energy storage system,rechargeable lithium-oxygen batteries(LOBs)still face substantial challenges caused by insulating discharge products that preclude their practical *** highly efficient cathode catalysts capable of facilitating formation/decomposition of discharge products is considered as an essential approach towards high performance ***,Pd decorated Te nanowires(Pd@Te NWs)were synthesized as advanced catalyst in LOBs to maximize Pd utilization and achieve synergistic effect,in which Pd clusters were uniformly grown on Te substrate though regulating the Pd:Te ***,Pd@Te nanowires assembled into an interpenetrating network-like structure by vacuum filtration and employed as flexible cathode,enabling LOBs achieved an ultralong 190 cycles stability and a superior specific capacity of 3.35 mAh·cm^(-2).Experimental studies and density functional theory(DFT)calculations reveal the excellent catalytic ability of Pd@Te and synergistic catalytic mechanism of Pd and Te,in which uniform electron distribution,extensive electron exchange,and large adsorption distance between Pd cluster and discharge products promote homogeneous adsorption/desorption of discharge products,while the high adsorption energy of Te substrate for li species reduces the initial dynamical energy barrier during discharging *** current work provides viable strategy to design composite catalysts for flexible cathode of LOBs with synergistic catalytic effects.

关键词： flexible lithium-oxygen batteries Pd@Te synergistic catalysis cathode catalysts density functional theory(DFT)calculation

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Gastric metastasis of small cell lung carcinoma:Three case reports and review of literature

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World Journal of Gastroenterology 2024年第31期30卷 3717-3725页

作者： Shan yang Qing-Yun He Qing-Jing Zhao Han-Tao yang Zheng-Yi yang Wen-Yi Che Hua-Mei li Hui-chao Wu Department of Gastroenterology The Affiliated Hospital of Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina Department of Gastroenterology Guizhou Hospital of The First Affiliated HospitalSun Yat-sen UniversityGuiyang 550000Guizhou ProvinceChina Department of Gastroenterology Zhejiang Provincial People's Hospital Bijie HospitalBijie 551700Guizhou ProvinceChina Department of Gastroenterology Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina

BACKGROUND Small cell lung carcinoma(SCLC)is highly susceptible to metastasis in the early stages of the ***,the stomach is an uncommon site of metastasis in SCLC,and only a few cases of this type of metastasis have been ***,SCLC gastric metastases have not been systematically characterized and are easily missed and *** SUMMARY We report three cases of gastric metastasis from SCLC in this *** first patient presented primarily with cough,hemoptysis,and epigastric *** other two patients presented primarily with abdominal discomfort,epigastric distension,and *** patients underwent gastroscopy and imaging ***,the immunohistochemical results of the lesions in three patients were suggestive of small cell ***,the three patients were diagnosed with gastric metastasis of SCLC through a comprehensive *** three patients did not receive appropriate treatment and died within a short *** Here,we focused on summarizing the characteristics of gastric metastasis of SCLC to enhance clinicians'understanding of this disease.

关键词： Small cell lung cancer Gastric neoplasms Neoplasm metastasis Diagnosis Case report

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Periodic event-triggered secure consensus for networked mechanical systems under Denial-of-Service attacks

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Control Theory and Technology 2024年第1期22卷 1-13页

作者： Shiqi Zheng Zhipeng li chao Zhai Peng Shi School of Automation China University of GeosciencesWuhan430074HubeiChina School of Electrical and Electronic Engineering The University of AdelaideAdelaideSA5005Australia School of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou350100FujianChina

This paper concentrates on the secure consensus problem of networked mechanical/Euler–Lagrange ***,a new periodic event-triggered(PET)secure distributed observer is proposed to estimate the leader *** proposed distributed observer only relies on the PET data from its neighbors,which can significantly reduce the communication and computational *** importantly,it is secure in the sense that it can work normally regardless of the Denial-of-Service(DoS)***,based on the proposed distributed observer,an adaptive fuzzy control law is proposed for each Euler–Lagrange system.A PET mechanism is integrated into the controller,which can reduce the control *** is helpful for both energy saving and fault tolerance of ***,the PET mechanism naturally makes the controller easy to be implemented in digital *** property of fuzzy logic systems and Gronwall inequality are skillfully utilized to show the stability of the closed-loop ***,the proposed control scheme is verified on real Euler–Lagrange systems,which contain a robot manipulator and several servo motors.

关键词： Output regulation Mechanical/Euler-Lagrange systems Periodic event-triggered mechanism Denial-of-Service attacks

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A Facile li_(2)TiO_(3) Surface Modification to Improve the Structure Stability and Electrochemical Performance of Full Concentration Gradient li-Rich Oxides

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Energy & Environmental Materials 2024年第3期7卷 41-48页

作者： Naifang Hu Yuan yang lin li Yuhan Zhang Zhiwei Hu Lan Zhang Jun Ma Guanglei Cui Qingdao Industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China Institute of Materials Science and Engineering Ocean University of ChinaQingdao 266100China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China Max Planck Institute for Chemical Physics of Solids Nothnitzer Strasse 40Dresden D-01187Germany CAS Key Laboratory of Green Process and Engineering Beijing Key Laboratory of Ionic Liquids Clean ProcessState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Shandong Energy Institute Qingdao 266101China

Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rate performance,whereas the high lithium residues on its surface impairs the structure stability and long-term cycle ***,a facile multifunctional surface modification method is implemented to eliminate surface lithium residues of full concentration gradient lithium-rich layered oxides by a wet chemistry reaction with tetrabutyl titanate and the post-annealing *** realizes not only a stable li_(2)TiO_(3)coating layer with 3D diffusion channels for fast li^(+)ions transfer,but also dopes partial Ti^(4+)ions into the sub-surface region of full concentration gradient lithium-rich layered oxides to further strengthen its crystal ***,the modified full concentration gradient lithium-rich layered oxides exhibit improved structure stability,elevated thermal stability with decomposition temperature from 289.57℃to 321.72℃,and enhanced cycle performance(205.1 mAh g^(-1)after 150 cycles)with slowed voltage drop(1.67 mV per cycle).This work proposes a facile and integrated modification method to enhance the comprehensive performance of full concentration gradient lithium-rich layered oxides,which can facilitate its practical application for developing higher energy density lithium-ion batteries.

关键词： full concentration gradient lithium-rich layered oxides structure stability surface modification

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Failure mechanisms and surface treatment processes of thermal barrier coatings: Review

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 20-40页

作者： li, Hao yang, Shengqiang li, Xiuhong li, Wenhui Taiyuan Univ Technol Coll Mech & Vehicle Engn Taiyuan 030024 Peoples R China Taiyuan Univ Technol Shanxi Prov Key Lab Precise Machining Taiyuan 030024 Peoples R China Taiyuan Univ Technol Coll Aeronaut & Astronaut Taiyuan 030024 Peoples R China

Thermal Barrier Coatings (TBCs) technology is key to improving the service temperature and the productivity of aircraft engines. The performance and failure life of TBCs are strongly influenced by surface integrity and microstructure. Therefore, recognizing failure mechanisms and developing effective surface treatment processes are crucial for further improving the reliability and durability of TBCs. This paper explains the primary reasons for TBC failure, emphasizing on how integrity of surface and interface influences interfacial oxidation, high-temperature erosion, and Calcium-Magnesium-Alumina-Silicate (CMAS) corrosion. Furthermore, this paper completely and rigorously evaluates the research status of TBCs surface treatment processes, including the characteristics and effects of various processes, and describes the requirements and goals of pretreatment and post-treatment. In addition, a potential direction for the development and application of TBCs surface treatment is suggested. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Thermal Barrier Coatings (TBCs) Failure Surface treatment processes Processing goals Mass finishing HOT CORROSION BEHAVIOR YTTRIA-STABIliZED ZIRCONIA HIGH-TEMPERATURE OXIDATION ELECTRON-BEAM CMAS CORROSION EROSION BEHAVIOR HEAT-TREATMENT GROWN OXIDE STRESS-DISTRIBUTION ADHESION STRENGTH

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