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Hot Compression Behavior and Tensile Property of a Novel Ni-Co-Based Superalloy Prepared by Electron Beam Smelting Layered Solidification Technology

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 283-292页

作者： Yong-Chao Gai Rui Zhang Chuan-Yong Cui Zi-Jian zhou yi Tan yi-zhou zhou Xiao-Feng Sun key laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The hot compression behavior and tensile strength after compression of a new Ni-Co-based superalloy produced using electron beam smelting layered(EBSL)solidification technology were *** compression tests were performed at temperatures of 1120℃and 1150℃,with strain rates of 1 s^(-1) and 0.01 s^(-1),reaching a true strain of *** strength was evaluated at room *** results revealed that this EBSL technology accelerates dynamic recrystallization(DRX),without compromising the strength of alloy.A significant correlation between the volume fraction of DRX and the strain rate was observed,with higher fractions at lower strain rates,leading to higher tensile ***,at the same strain rate,the specimens compressed at 1120℃exhibited higher tensile strength due to undissolvedγ′*** solution and aging heat treatment,the alloy maintained high tensile *** results suggested that the EBSL Ni-Co-based superalloy offers excellent prospects for practical applications.

关键词： Ni-Co-based superalloy Hot deformation Electron beam smelting Tensile strength

Efficient 2-D MUSIC algorithm for super-resolution moving target tracking based on an FMCW radar

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Geodesy and Geodynamics 2024年第5期15卷 504-515页

作者： Xuchong yi Shuangxi Zhang Yuxuan zhou School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China key laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan 430079China

Frequency modulated continuous wave(FMCW)radar is an advantageous sensor scheme for target estimation and environmental ***,existing algorithms based on discrete Fourier transform(DFT),multiple signal classification(MUSIC)and compressed sensing,etc.,cannot achieve both low complexity and high resolution *** paper proposes an efficient 2-D MUSIC algorithm for super-resolution target estimation/tracking based on FMCW ***,we enhance the efficiency of 2-D MUSIC azimuth-range spectrum estimation by incorporating 2-D DFT and multi-level resolution searching ***,we apply the gradient descent method to tightly integrate the spatial continuity of object motion into spectrum estimation when processing multi-epoch radar data,which improves the efficiency of continuous target *** two approaches have improved the algorithm efficiency by nearly 2-4 orders of magnitude without losing accuracy and *** experiments are conducted to validate the effectiveness of the algorithm in both single-epoch estimation and multi-epoch tracking scenarios.

关键词： 2D-MUSIC FMCW radar Moving target tracking Super-resolution Algorithm optimization

Remarks on the Global Existence for Incompressible Navier-Stokes Equations

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Chinese Annals of mathematics,Series B 2024年第4期45卷 529-536页

作者： Sheng WANG Zexian ZHANG yi zhou Shanghai Center for Mathematical sciences Fudan UniversityShanghai 200433China School of mathematics Science Fudan UniversityShanghai 200433China

In this article,the authors use the special structure of helicity for the threedimensional incompressible Navier-Stokes equations to construct a family of finite energy smooth solutions to the Navier-Stokes equations ... 详细信息

关键词： Navier-Stokes euqations Helicity Global existence Critical norm

Reliable calculations of nuclear binding energies by the Gaussian process of machine learning

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Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： Zi-yi Yuan Dong Bai Zhen Wang Zhong-zhou Ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science Hohai UniversityNanjing 211100China key laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 223. nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 83., 13.484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L0513.2(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.

关键词： Nuclear binding energies decay Machine learning Gaussian process

VARIATIONAL ANALYSIS FOR THE MAXIMAL TIME FUNCTION IN NORMED SPACES

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Acta Mathematica Scientia 2024年第5期44卷 1696-1706页

作者： Ziyi zhou yi JIANG School of Mathematical sciences Visual Computing and Virtual Reality Key LaboratorySichuan Normal UniversityChengdu610066China

For a general normed vector space,a special optimal value function called a maximal time function is *** covers the farthest distance function as a special case,and has a close relationship with the smallest enclosing ball *** properties of the maximal time function are proven,including the convexity,the lower semicontinuity,and the exact characterizations of its subdifferential formulas.

关键词： maximal time function subdifferential normal cone nonsmooth analysis

Distinct Interannual Variability and Physical Mechanisms of Snowfall Frequency over the Eurasian Continent during Autumn and Winter

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Advances in Atmospheric sciences 2024年第10期41卷 1969-1983,I0011-I0013页

作者： Siyu zhou Bo SUN Huijun WANG yi ZHENG Jiarui CAI Huixin LI Botao zhou Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/key laboratory of Meteorological Disasters Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China Southern Marine Science and Engineering Guangdong laboratory Zhuhai 519080China Nansen Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

This study investigates the dominant modes of interannual variability of snowfall frequency over the Eurasian continent during autumn and winter,and explores the underlying physical *** first EOF mode(EOF1)of snowfall frequency during autumn is mainly characterized by positive anomalies over the Central Siberian Plateau(CSP)and Europe,with opposite anomalies over Central Asia(CA).EOF1 during winter is characterized by positive anomalies in Siberia and negative anomalies in Europe and East Asia(EA).During autumn,EOF1 is associated with the anomalous sea ice in the Kara–Laptev seas(KLS)and sea surface temperature(SST)over the North *** sea ice in the KLS may cause an increase in the meridional air temperature gradient,resulting in increased synoptic-scale wave activity,thereby inducing increased snowfall frequency over Europe and the *** increases of both sea ice in the KLS and SST in the North Atlantic may stimulate downstream propagation of Rossby waves and induce an anomalous high in CA corresponding to decreased snowfall *** contrast,EOF1 is mainly affected by the anomalous atmospheric circulation during *** the positive phase of the North Atlantic Oscillation(NAO),an anomalous deep cold low(warm high)occurs over Siberia(Europe)leading to increased(decreased)snowfall frequency over Siberia(Europe).The synoptic-scale wave activity excited by the positive NAO can induce downstream Rossby wave propagation and contribute to an anomalous high and descending motion over EA,which may inhibit *** NAO in winter may be modulated by the Indian Ocean dipole and sea ice in the Barents-Kara-Laptev Seas in autumn.

关键词： snowfall frequency Eurasian continent sea ice atmospheric circulation interannual variability Indian Ocean dipole

Nanomaterial Assisted Exosome Analysis Using Mass Spectrometry

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Chemical Research in Chinese Universities 2024年第2期40卷 237-254页

作者： ZHANG yi zhou Bokai LI Qiuning JIN Mingshi BAI Yu Beijing National laboratory for Molecular sciences Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871P.R.China Department of Chemistry Yanbian UniversityYanji133002P.R.China

Exosomes,extracellular vesicles(EVs)that play crucial roles in biological processes,have emerged as attractive targets for noninvasive disease diagnosis and *** spectrometry(MS)offers high sensitivity,high throughput,and excellent qualification and quantification capacity,which is the ideal approach for exosome ***’unique physiochemical properties,controllable morphology,and large surface area make them promising in biological sample pretreatment and *** contributed diverse functions to the exosome MS analysis,encompassing substrates for exosome isolation and cargos enrichment,matrices for laser desorption/ionization(LDI),read-out signals and supporters for signal amplification strategies,*** this review,recent progress in the applications of nanomaterial in the exosome MS analysis was summarized and a comprehensive discussion on the challenges and perspectives was proposed for the development of an advancing analysis approach of exosomes for the accurate diagnosis and monitoring of diseases.

关键词： Exosome Nanomaterial Enrichment Matrix Mass spectrometry

Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng zhou Yu Long Yan-Liang yi Cheng Deng Lian-Xi Hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE key laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.3. and 11.19 GPa,*** a result,the microhardness of coating increases from HV53..25 to HV 73..16,the wear rate decreases from3..4×10^(-3.to 6.1×10^(-3.mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

Therapeutic Role of Chinese Medicine Targeting Nrf2/HO-1 Signaling Pathway in Myocardial Ischemia/Reperfusion Injury

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Chinese Journal of Integrative Medicine 2024年第10期30卷 949-960页

作者： LIU Chang-xing GUO Xin-yi zhou Ya-bin WANG He First Clinical Medical School Heilongjiang University of Chinese MedicineHarbin150040China Clinical Medical School Chengdu University of Traditional Chinese MedicineChengdu610036China Department of Cardiology the First Affiliated Hospital of Heilongjiang University of Chinese MedicineHarbin150040China

Acute myocardial infarction(AMI),characterized by high incidence and mortality rates,poses a significant public health *** therapy,though the preferred treatment for AMI,often exacerbates cardiac damage,leading to myocardial ischemia/reperfusion injury(MI/RI).Consequently,the development of strategies to reduce MI/RI is an urgent priority in cardiovascular *** medicine,recognized for its multi-component,multi-pathway,and multi-target capabilities,provides a novel approach for alleviating MI/RI.A key area of interest is the nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)*** pathway is instrumental in regulating inflammatory responses,oxidative stress,apoptosis,endoplasmic reticulum stress,and ferroptosis in MI/*** paper presents a comprehensive overview of the Nrf2/HO-1 signaling pathway's structure and its influence on MI/***,it reviews the latest research on leveraging Chinese medicine to modulate the Nrf2/HO-1 pathway in MI/RI treatment.

关键词： nuclear factor E2-related factor 2/heme oxygenase-1 signaling pathway myocardial ischemia/reperfusion injury Chinese medicine mechanisms