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Inner fission barriers of uranium isotopes in the deformed relativistic Hartree-Bogoliubov theory in continuum

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chinese Physics C 2024年第10期48卷 214-221页

作者： Wei Zhang Jin-ke Huang Ting-Ting Sun Jing peng Shuang-quan Zhang School of Physics Zhengzhou UniversityZhengzhou 450001China Department of Physics Beijing Normal UniversityBeijing 100875China State key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

The inner fission barriers of the even-even uranium isotopes from the proton to the neutron drip line are examined using the deformed relativistic Hartree-Bogoliubov theory in continuum.A periodic-like evolution for the ground state shapes is shown with respect to the neutron number,i.e.,spherical shapes at shell closures 126,184,258,and prolate dominated shapes between *** to the shape evolution,the inner fission barriers also exhibit a periodic-like behavior:peaks at the shell closures and valleys in the *** triaxial effect on the inner fission barrier is evaluated using triaxial relativistic mean field calculations combined with a simple BCS method for *** the triaxial correction is included,the inner barrier heights show good consistency with available empirical ***,the evolution from the proton to the neutron drip line aligns with results from the multi-dimensionally constrained relativistic mean field theory.A flat valley in the fission barrier height is predicted around the neutron-rich nucleus U which may play a role of fission recycling in astrophysical r-process nucleosynthesis.

关键词： inner fission barrier potential energy curve triaxiality deformed relativistic Hartree-Bogoliubov theory in continuum

Supermassive black holes triggered by QCD axion bubbles

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Communications in Theoretical Physics 2024年第5期76卷 134-139页

作者： Hai-Jun Li Ying-quan peng Wei Chao Yu-Feng Zhou key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Center for Advanced quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China School of Physical sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/HangzhouChina

Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still *** this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion *** this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after *** QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase *** consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))*** PBHs at this mass region may account for the seeds of SMBHs.

关键词： supermassive black holes primordial black holes quantum chromodynamics axion

Interface strengthening for thermal sprayed WC-10Co4Cr coating subjected to pulsed magnetic treatment

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Rare Metals 2024年第2期43卷 780-795页

作者： Cheng-Kai Qian Qu Liu Heng Wang ke-Jian Li Zhi-peng Cai Department of Mechanical Engineering Tsinghua UniversityBeijing100084China Tianjin Research institute for Advanced Equipment Tsinghua UniversityTianjin300304China State key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing100084China

The reliability of the coated industry components demands ideal fatigue properties of the coating,and it is mainly determined by the performance of the *** this study,pulsed magnetic treatment(PMT)was applied to the thermal sprayed WC-10Co4Cr coating,and the fatigue lifetime of the coated bolt increased by 219.82%under an imitation of the operating mode *** tests further proved that both the adhesion and cohesion strength were improved after PMT,and they benefit from the interface strengthening *** formation of coherent WC/Co interfaces was characterized by in-situ transmission electron microscopy(TEM),and the molecular dynamic simulations indicate that the work of separation of these interfaces is much higher than the original disordered *** stress was relaxed and distributed more homogeneously after PMT,and it mainly contributes to the coating/substrate *** work provides a new post-treatment method focusing on the interfaces in the WC-based coating and gives insight into its mechanism so that it is hopeful to be applied to other kinds of coatings.

关键词： Cemented carbide coating Pulsed magnetic treatment Interface strengthening Fatigue properties Adhesion strength

Effect of Phase Separation Size on the Properties of Self-healing Elastomer

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chinese Journal of Polymer Science 2024年第6期42卷 798-804页

作者： Jun Xu Lei Zhu Xian-Qi Feng Cong Sui Wen-peng Zhao Shou-ke Yan School of Chemical Engineering Qingdao University of Science&TechnologyQingdao266042China College of Engineering Yanching institute of TechnologyLangfang065210China key Laboratory of Rubber-plastics Qingdao University of Science&TechnologyQingdao266042China State key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China

Regulation of phase structure has been recognized as one of the most effective ways to fabricate self-healing polymers with high mechanical *** mechanical properties of the resultant polymers are certainly affected by the size of separated phase ***,the study on this aspect is absence,because it can hardly exclude the influence of variation in monomer proportion required for tuning the separated phase ***,we report the first study on tuning the phase size through reversible addition-fragmentation chain transfer(RAFT)polymerization without changing the proportion of *** expected,the size of separated phase has been successfully mediated from 15 nm to 9 nm by tuning the molecular weight of the chain transfer *** is found that the mechanical strength and the self-healing efficiency of the resultant polymers increase simultaneously with the decrease of phase *** study on the formation kinetics of hydrogen bonds reveals that the decrease of phase size can facilitate the re-bonding rate of hydrogen bonds,even if the migration of polymer chains is restricted.

关键词： Self-healing polymers Phase separation Reversible addition-fragmentation chain transfer

Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

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Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie Xue-yuan Jiang Hai-yan Tang ·Gen Li Yu-hang Wang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053.0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3.→CeAlO_(3.→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053.wt.%,the stable phase in steel was Ce2O3.while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3..As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3. inclusions in steel while promote the formation of CeAIO3.and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

Origin of the near-room temperature resistance transition in lutetium with H2/N2 gas mixture under high pressure

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National Science Review 2024年第7期11卷 26-32页

作者： Di peng Qiaoshi Zeng Fujun Lan Zhenfang Xing Zhidan Zeng Xiaoxing ke Yang Ding Ho-kwang Mao key Laboratory of Materials Physics Institute of Solid State Physics Hefei Institutes of Physical Science(HFIPS)Chinese Academy of Sciences Science Island Branch Graduate School of University of Science and Technology of China Center for High Pressure Science and Technology Advanced Research Shanghai key Laboratory of Material Frontiers Research in Extreme Environments(MFree) Shanghai Advanced Research in Physical Sciences(SHARPS) State key Laboratory of Superhard Materials Institute of PhysicsJilin University College of Materials Science&Engineering Beijing University of Technology

The recent report of room-temperature superconductivity at near-ambient pressure in nitrogen-doped lutetium hydride（Lu-H-N） by Dasenbrock-Gammon et al. [Nature 615, 244–250（2023.] has attracted tremendous attention due to its anticipated great impact on technology. However, the results could not be independently reproduced by other groups worldwide in follow-up studies, which elicited intense controversy. Here, we develop a reliable experimental protocol to minimize the extensively concerned extrinsic influences on the sample by starting the reaction from pure lutetium loaded with an H2/N2gas mixture in a diamond anvil cell under different pressures and temperatures and simultaneously monitoring the entire chemical reaction process using in situ four-probe resistance measurements. Therefore, we could repeatedly reproduce the near-room temperature upsurge of electrical resistance at a relatively early stage of the chemical reaction. However, the mechanism is suggested to be a metal-to-semiconductor/insulator transition associated with the structural modulation in the non-stoichiometric Lu-H-N, rather than superconductivity.

关键词： superconductivity high pressure lutetium hydride resistance transition metal-to-semiconductor/insulator transition

Development of a Mengla virus minigenome and comparison of its polymerase complexes with those of other filoviruses

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Virologica Sinica 2024年第3期39卷 459-468页

作者： Shi-Zhe Xie ke Yao Bei Li Cheng peng Xing-Lou Yang Zheng-Li Shi State Laboratory of Virology Wuhan Institute of VirologyChinese Academy of SciencesWuhan430071China University of chinese academy of sciences Beijing100049China Yunnan key Laboratory of Biodiversity Information Kunming Institute of ZoologyChinese Academy of SciencesKunming650201China Hubei Jiangxia Laboratory Wuhan430200China

Ebola virus(EBOV)and Marburg virus(MARV),members of the Filoviridae family,are highly pathogenic and can cause hemorrhagic fevers,significantly impacting human *** are considered reservoirs of these viruses because related filoviruses have been discovered in ***,due to the requirement for maximum containment laboratories when studying infectious viruses,the characterization of bat filoviruses often relies on pseudoviruses and minigenome *** this study,we used RACE technology to sequence the 3.-leader and 50-trailer of Mengla virus(MLAV)and constructed a *** to MARV,the transcription activities of the MLAV minigenome are independent of *** further assessed the effects of polymorphisms at the 50 end on MLAV minigenome activity and identified certain mutations that decrease minigenome reporter efficiency,probably due to alterations in the RNA secondary *** reporter activity upon recombination of the 3.-leaders and 50-trailers of MLAV,MARV,and EBOV with those of the homologous or heterologous minigenomes was compared and it was found that the polymerase complex and leader and trailer sequences exhibit intrinsic ***,we investigated whether the polymerase complex proteins from EBOV and MARV support MLAV minigenome RNA synthesis and found that the homologous system is more efficient than the heterologous *** efficiently inhibited MLAV as well as EBOV *** summary,this study provides new information on bat filoviruses and the minigenome will be a useful tool for high-throughput antiviral drug screening.

关键词： Bat filovirus Mengla virus(MLAV) Minigenome Replication Antiviral drug screening

Advancements in machine learning for material design and process optimization in the field of additive manufacturing

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China Foundry 2024年第2期21卷 101-115页

作者： Hao-ran Zhou Hao Yang Huai-qian Li Ying-chun Ma Sen Yu Jian shi Jing-chang Cheng peng Gao Bo Yu Zhi-quan Miao Yan-peng Wei National key Laboratory of Advanced Casting Technologies Shenyang Research Institute of Foundry Co.Ltd.CAMShenyang 110022China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China key Laboratory of Space Physics Beijing 100076China School of Materials Science and Engineering Nanyang Technological University639798Singapore

Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric ***,the development of additive manufacturing process is constrained by issues like unclear fundamental principles,complex experimental cycles,and high *** learning,as a novel artificial intelligence technology,has the potential to deeply engage in the development of additive manufacturing process,assisting engineers in learning and developing new *** paper provides a comprehensive overview of the research and applications of machine learning in the field of additive manufacturing,particularly in model design and process ***,it introduces the background and significance of machine learning-assisted design in additive manufacturing *** then further delves into the application of machine learning in additive manufacturing,focusing on model design and process ***,it concludes by summarizing and forecasting the development trends of machine learning technology in the field of additive manufacturing.

关键词： additive manufacturing machine learning material design process optimization intersection of disciplines embedded machine learning

Unveiling factuality and injecting knowledge for LLMs via reinforcement learning and data proportion

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Science China(Information sciences) 2024年第10期67卷 389-390页

作者： Wenjun ke Ziyu SHANG Zhizhao LUO peng WANG Yikai GUO Qi LIU Yuxuan CHEN School of Computer Science and Engineering Southeast University key Laboratory of New Generation Artificial Intelligence Technology and Its Interdisciplinary Applications(Southeast University) beijing institute of Technology Zhuhai beijing institute of Computer Technology and Application

Large language models(LLMs) have demonstrated remarkable effectiveness across various natural language processing(NLP) tasks, as evidenced by recent studies [1, 2]. However, these models often produce responses that conflict with reality due to the unreliable distribution of facts within their training data, which is particularly critical for applications requiring high credibility and accuracy [3..

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