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Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

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Nuclear Science and Techniques 2024年第3期35卷 109-141页

作者： Hui liu Guan-Hong lei he-Fei Huang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research *** paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt *** competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this *** approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.

关键词： Irradiation and corrosion Synergistic effect Austenitic stainless steels Nickel-based alloys Reactors

Effects of vibration conditions,spatial confinement and friction on mixing and segregation characteristics of mixed pebble beds for CFETR WCCB blanket

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Particuology 2024年第2期85卷 268-279页

作者： Yong liu Chongyang he Cong Wang lei Chen Songlin liu Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230027China Chengdu University Chengdu610106China Zhejiang Lab Hangzhou310000China

This paper presents the study of the dynamic characteristics of confined mixed pebble beds with different friction under different vibration conditions using the discrete element ***λsegre-gation index is used to quantify the degree of particle mixing or *** percolation,convection and diffusion mechanisms are responsible for the segregation patterns of the mixed *** results show the degree of segregation can be suppressed by decreasing the vibration acceleration or free space height below a *** simulation reveals the threshold of vibration acceleration or free space height both are related to the bed height increment which determines the strength of the percolation *** addition,the strength of percolation and convection becomes weaker by decreasing the friction of particles and walls,which makes the pebbled bed remains in a mixed state under *** findings are significant to clarify the main factors behind the three segregation mechanisms and hence provide solutions to retaining the mixed state of the Li2TiO3&Be12Ti mixed pebble bed.

关键词： Vibration Segregation Binary pebble bed Discrete element method

heavy element contributions of rotating massive stars to interstellar medium

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Research in Astronomy and Astrophysics 2021年第5期21卷 287-295页

作者： Rui-Qing Wu Chun-Hua Zhu Guo-Liang Lv Zhao-Jun Wang he-lei liu School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China

Employing the stellar evolution code Modules for Experiments in Stellar Astrophysics(MESA),we calculate yields of heavy elements from massive stars via stellar wind and core−collapse supernova(CCSN)ejecta to the interstellar medium(ISM).In our models,the initial masses(Mini)of massive stars are taken from 13 to 80 M⊙,their initial rotational velocities(V)are 0,300 and 500 km s^(−1),and their metallicities are[Fe/H]=−3,−2,−1 and *** yields of heavy elements coming from stellar winds are mainly affected by stellar rotation which changes the chemical abundances of stellar surfaces via chemically homogeneous evolution,and enhances mass-loss *** estimate that the stellar wind can produce heavy element yields of about 10^(−2)(for low metallicity models)to a mass of severalM⊙(for low metallicity and rapid rotation models).The yields of heavy elements produced by CCSN ejecta also depend on the large amount of remnantmass which is mainly determined by the mass of the *** models calculate that the yields of heavy elements produced by CCSN ejecta can get up to several M⊙.Compared with stellar wind,CCSN ejecta has a greater contribution to the heavy elements in *** also compare the 56Ni yields calculated in this work with the observational *** models only explain the 56Ni masses produced by faint SNe or normal SNe with progenitor mass lower than about 25 M⊙,and greatly underestimate the 56Ni masses produced by stars with masses higher than about 30M⊙.

关键词： Stars:massive rotation ISM:abundances

Crust Cooling of Soft X-Ray Transients——the Uncertainties of Shallow heating

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Research in Astronomy and Astrophysics 2022年第5期22卷 165-175页

作者： Xiang-Yang Lu Guo-Liang Lü he-lei liu Chun-Hua Zhu Zhao-Jun Wang School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Center for Theoretical Physics Xinjiang UniversityUrumqi 830046China

Crust cooling of soft X-ray transients has been observed after outbursts,but an additional shallow heating during accretion in outburst is needed to explain the quiescent light ***,shallow heating is significantly different between sources and even within one source between different outbursts,and the source of shallow heat is as yet *** the open source code"dStar"which solves the fully general relativistic heat diffusion equation for the crust,we investigate the effect of magnitude and depth of shallow heating on crust cooling and find that some exceptional sources(Swift J174805.3-244637,MAXI J0556-332 during outburstⅡand GRO J1750-27)in which shallow heating may be inactive could be explained by a deeper shallow heating *** compare our results with those from previous works and find that the shallow heating is model *** addition,the effects of mass and radius of a neutron star on shallow heating are studied,and it is shown that the more compact the star,the less shallow heating will be needed to fit the crust cooling light curves.

关键词： stars neutron-X-rays:binaries-stars individual(GROJ1750-27)-X-rays burs

Dendritic Learning and Miss Region Detection-Based Deep Network for Multi-scale Medical Segmentation

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Journal of Bionic Engineering 2024年第4期21卷 2073-2085页

作者： Lin Zhong Zhipeng liu Houtian he Zhenyu lei Shangce Gao Faculty of Engineering University of ToyamaToyama9300887Japan

Automatic identification and segmentation of lesions in medical images has become a focus area for *** for medical image provides professionals with a clearer and more detailed view by accurately identifying and isolating specific tissues,organs,or lesions from complex medical images,which is crucial for early diagnosis of diseases,treatment planning,and efficacy *** paper introduces a deep network based on dendritic learning and missing region detection(DMNet),a new approach to medical image *** combines a dendritic neuron model(DNM)with an improved SegNet framework to improve segmentation accuracy,especially in challenging tasks such as breast lesion and COVID-19 CT scan *** work provides a new approach to medical image segmentation and confirms its *** have demonstrated that DMNet outperforms classic and latest methods in various performance metrics,proving its effectiveness and stability in medical image segmentation tasks.

关键词： Medical image segmentation Dendritic learning Deep supervision Dynamic focal loss

A Fast Insertion Tabu Search with Conflict-Avoidance heuristic for the Multisatellite Multimode Crosslink Scheduling Problem

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Tsinghua Science and Technology 2024年第3期29卷 843-862页

作者： Weiyi Yang lei he Xiaolu liu Weican Meng Yingwu Chen College of Systems Engineering National University of Defense TechnologyChangsha 410000China Beijing Institude of Tranking and Telecommunication Technology Beijing 100000China

An agile earth-observing satellite equipped with multimode cameras capable of transmitting observation data to other satellites is developed to rapidly respond to requests with multiple observation *** gives rise to the Multisatellite Multimode Crosslink Scheduling(MMCS)problem,which involves allocating observation requests to agile satellites,selecting appropriate timing and observation modes for the requests,and transmitting the data to the ground station via the satellite communication ***,a mixed integer programming model is introduced to include all complex time and operation *** solve the MMCS problem,a two-stage heuristic method,called Fast insertion Tabu Search with Conflict-avoidance(FTS-C)heuristic,is *** the first stage,a conflict-avoidance insertion algorithm is designed to generate a high-quality initial solution by considering the requests transmission and ***,the tabu search-based second stage optimizes the initial ***,an extensive empirical study based on a real-world situation demonstrates that FTS-C can generate a solution with higher quality in less time than other state-of-the-art algorithms and the CPLEX solver.

关键词： earth observation satellites scheduling tabu search heuristic data transmission and download mixedinteger programming model

Neutrino luminosity of stars with different masses

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Research in Astronomy and Astrophysics 2020年第1期20卷 35-42页

作者： Yang Shi Xun Xue Chun-Hua Zhu Zhao-Jun Wang he-lei liu Lin Li Guo-Liang Lü School of Physics and Technology Xinjiang UniversityUrumqi 830046China Department of Physics East China Normal UniversityShanghai 2000062China

Neutrinos play an important role in stellar *** are produced by nuclear reactions or thermal *** the stellar evolution code Modules for Experiments in Stellar Astrophysics(MESA),we study stellar neutrino luminosity with different *** neutrino luminosities of stars with different initial masses at different evolutionary stages are *** find that the neutrino flux of a star with 1 M⊙ mass at an evolutionary age of 4.61×10^9 yr is consistent with that of the *** general,neutrinos are produced by nuclear reactions,and the neutrino luminosity of stars is about one or two magnitudes lower than the photo ***,neutrino luminosity can exceed photo luminosity during the helium flash which can occur for stars with a mass lower than 8 M⊙.Although the helium flash does not produce neutrinos,plasma decay,one of the thermal processes,can efficiently make neutrinos during this *** to the high mass-loss rate,a star with a mass of 9 M⊙ does not undergo the helium *** neutrinos mainly originate from nuclear reactions until the end of the AGB *** the end of the AGB stage,its neutrino luminosity results from plasma decay which is triggered by the gravitational energy release because of the stellar core contracting.

关键词： stars:evolution stars:fundamental parameters nuclear reactions nucleosynthesis abundances

Distribution, bioaccumulation, trophic transfer and risk assessment of trace elements in fish from a typical shallow outflow lake basin, China

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 141-156页

作者： Miao he Guijian liu Xiaodan Shi lei Wu Qiang Chen CAS Key Laboratory of Crust-Mantle Materials and Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Anhui Academy of Environmental Sciences Hefei 230022China School of Resources and Environmental Engineering Hefei University of TechnologyHefei 230009China

Fish are important food sources for humans,and the availability of appropriate amount of trace elements(TEs)plays a crucial role in fish ***,due to large volumes of sewage discharge,high levels of certain elements are present in aquatic environments,and these elements accumulate in fish and potentially affect human *** this study,the distribution and bioaccumulation capacity of trace elements in six dominant fish species from Chaohu Lake(China)were *** results showed that the bioaccumulation capacity of fish for Zn was greater than other *** the source of the TEs in the fish were explored along with the concentration of the TEs in the aquatic environment,which indicated that TEs in fish were mainly obtained through ingestion and indirectly affected by the industrial activities in the ***,stable carbon and nitrogen isotopes were used to classify the trophic levels and explore the biological magnification of TEs of the *** was found that Sb and Sr showed biomagnification with the increase of trophic level of *** on the above analyses,the environmental biogeochemical cycle model of TEs in the lake was distinguished and established,which can offer valuable insights for sustainable fishery management in the downstream Yangtze River Delta ecosystem.

关键词： Trophic level Bioaccumulation Risk assessment Trace elements

A study of type I X-ray bursts from an NS accreting pure helium

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Research in Astronomy and Astrophysics 2020年第4期20卷 44-48页

作者： Yan-Cun Ma he-lei liu Chun-Hua Zhu Zhao-Jun Wang Lin Li Guo-Liang Lü School of Physics and Technology Xinjiang UniversityUrumqi 830046China

Using the Modules for Experiments in Stellar Astrophysics(MESA) code, we investigate Type I X-ray bursts(XRBs) produced by neutron stars(NSs) accreting pure helium, which are called intermediate XRBs in observations. We simulate 21 models for intermediate XRBs with various mass-accretion rates(M) from 2.5 × 10^-8 to 5 × 10^-10 M⊙yr^-1. Compared with normal XRBs, in which the NS accretes matter with solar metallicity, intermediate XRBs have higher luminosity and longer recurrence time,which are essentially consistent with observations. We find that the recurrence time of intermediate XRBs is proportional to M^-2.0.

关键词： stars:accretion star:neutron stars