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Three-dimensional fracture of UO_(2)ceramic pellets by phase field modeling

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 165-176页

作者： Wei Xiong Xuan Ye Hongzhang Cheng Xiaoming Liu institute of nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Fracture is the primary failure type for the UO_(2)ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional(3D)UO_(2)ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.

关键词： phase field method nuclear fuel pellet coupled thermo-mechanical model thermal fracture

Machine learning for online control of particle accelerators

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 94-104页

作者： Xiaolong Chen Zhijun Wang Yuan He Hong Zhao Chunguang Su Shuhui Liu Weilong Chen Xiaoying Zhao Xin Qi Kunxiang Sun Chao Jin Yimeng Chu Hongwei Zhao institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Advanced Energy Science and Technonlogy Guangdong Laboratory Huizhou 516000China Department of Physics Xiamen UniversityXiamen 361005China

Particle accelerators play a critical role in modern scientific ***,existing manual beam control methods heavily rely on experienced operators,leading to significant time consumption and potential challenges in managing next-generation accelerators characterized by higher beam current and stronger nonlinear *** this paper,we establish a dynamical foundation for designing the online adaptive controller of accelerators using machine *** provides a guarantee for dynamic controllability for a class of scientific instruments whose dynamics are described by spatial-temporal equations of motion but only part variables along the instruments under steady states are *** necessity of using historical time series of beam diagnostic data is *** strategies involve also employing a well-established virtual beamline of accelerators,by which various beam calibration scenarios that actual accelerators may encounter are *** the reinforcement learning algorithm is adopted to train the controller with the interaction to the virtual ***,the controller is seamlessly transitioned to real ion accelerators,enabling efficient online adaptive control and ***,the controller demonstrates significant robustness,effectively managing beams with diverse charge mass ratios without requiring *** a controller allows us to achieve the global control within the entire superconducting section of the China Accelerator Facility for Superheavy Elements.

关键词： nonlinear complex system adaptive control machine learning particle accelerator simulation to reality

Establishing the vector-meson-exchange dominance for the short range interactions of light quarks

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Science China(Physics,Mechanics & Astronomy) 2025年第3期68卷 190-191页

作者： Bing-Song Zou Department of Physics Tsinghua UniversityBeijing100084China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing100190China School of Physics University of Chinese Academy of SciencesBeijing100049China Southern Center for nuclear-Science Theory(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou516000China

Understanding the interactions between constituent quarks is one of the fundamental and challenging problems in hadron *** present,the constituent quark models have achieved great success in describing the properties of hadrons,whereas some long-standing disputes remain,especially for the short range interactions between constituent *** exploring the dynamic mechanism between u/d quarks,it is found that the one gluon exchange and/or vector meson exchange induced interactions may dominate the short range interactions[1].

关键词： quark exchange meson

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A single-pixel elemental imaging method using neutron-induced gamma-ray activation

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nuclear Science and Techniques 2025年第1期36卷 1-12页

作者： Can Cheng Yong-Ji Xie Xun-Rong Xia Jia-Yu Gu Dong Zhao Yi-Ze Chen Ai-Yun Sun Xu-Wen Liang Wen-Bao Jia Da-Qian Hei Department of Ionizing Radiation and Medical Engineering Jiangsu Institute of MetrologyNanjing 210023China institute of nuclear Analytical Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China China nuclear Power Engineering Co. LtdBeijing 100840China School of nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an ***,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating *** this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the *** of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization *** results demonstrate that the elemental imaging of the sample can be accurately determined using this *** proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.

关键词： Elemental imaging Neutron-induced gamma-ray activation Single-pixel imaging

Systematic experimental investigation on pressure build-up characteristics of water-jet injection into a molten LBE pool

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nuclear Science and Techniques 2025年第1期36卷 161-174页

作者： Hao-Ran Huang Zi-Jian Deng Song-Bai Cheng Jia-Yue Chen Sino‑French institute of nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China College of nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China

In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-based alloy(typically pure lead or lead-bismuth eutectic(LBE))is used as the *** clarify the pressure build-up characteristics under water-jet injection,this study conducted several experiments by injecting pressurized water into a molten LBE pool at Sun Yat-sen *** obtain a further understanding,several new experimental parameters were adopted,including the melt temperature,water subcooling,injection pressure,injection duration,and nozzle *** detailed analyses,it was found that the pressure and temperature during the water-melt interaction exhibited a consistent variation trend with our previous water-droplet injection mode LBE ***,the existence of a steam explosion was confirmed,which typically results in a much stronger pressure *** the non-explosion cases,increasing the injection pressure,melt-pool temperature,nozzle diameter,and water subcooling promoted pressure build-up in the melt ***,a limited enhancement effect was observed when increasing the injection duration,which may be owing to the continually rising pressure in the interaction vessel or the isolation effect of the generated steam *** of whether a steam explosion occurred,the calculated mechanical and kinetic energy conversion efficiencies of the melt were relatively small(not exceeding 4.1%and 0.7%,respectively).Moreover,the range of the conversion efficiency was similar to that of previous water-droplet experiments,although the upper limit of the jet mode was slightly lower.

关键词： Lead-cooled fast reactor Steam generator tube rupture accident Pressure build-up characteristics Experimental study Pressure water-jet injection

Long-duration aqueous Zn-ion batteries achieved by dual-salt highly-concentrated electrolyte with low water activity

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Journal of Energy Chemistry 2025年第2期101卷 778-785页

作者： Lvzhang Jiang Lingbo Yao Gege Wang Chang Liu Xiaowei Chi Yu Liu Shanghai institute of Ceramics Chinese Academy of Sciences University of Chinese Academy of sciences

Aqueous Zn-ion batteries have attracted much attention due to their unique high safety and low-cost ***,their practical applications are at a slow pace due to their short cycle life,which fundamentally results from the instability of the positive/negative electrode interface in the traditional dilute aqueous electrolytes with high water *** highly concentrated electrolyte（HCE）has been considered as an effective *** previous studies of single salt-based HCE（SSHCE）,herein,a new dual-salt HCE（15 m ZnCl2+10 m NH4NH2SO3DS-HCE） was proposed for the first ***-HCE was proven to simultaneously possess higher conductivity than traditional dilute electrolytes and ultralow water activity of SS-HCE by the regulation of dual high-concentration salts on the solvation structure,which renders the Zn‖Zn symmetric cell the record-long cycling life of 2200 h compared with those with SS-HCE（30 m ZnCl2,300 h） and other reported ***,the Zn‖NH4V4O10full cell with DS-HCE demonstrated impressed rate capability within a wide-range current densities from 0.1 to 10 A ***,at the high current density of 5 A g-1,the full cell shows almost100% capacity retention after 4000 cycles,which indicates the promising future of the DS-HCE system for long-duration aqueous Zn-ion batteries.

关键词： Ammonium vanadate Aqueous zinc battery Cycling stability Electrolyte

A monolithic 3D IGZO-RRAM-SRAM-integrated architecture for robust and efficient compute-in-memory enabling equivalent-ideal device metrics

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Science China(Information sciences) 2025年第2期68卷 322-337页

作者： Shengzhe YAN Zhaori CONG Zi WANG Zhuoyu DAI Zeyu GUO Zhihang QIAN Xufan LI Xu ZHENG Chuanke CHEN Nianduan LU Chunmeng DOU Guanhua YANG Xiaoxin XU Di GENG Jinshan YUE Lingfei WANG Ling LI Ming LIU institute of Microelectronics of the Chinese Academy of sciences University of Chinese Academy of sciences

Compute-in-memory(CIM) based on various devices such as static random access memory(SRAM) and resistive random access memory(RRAM) and other emerging devices such as indium-gallium-zinc-oxide(IGZO) transistor, magnetoresistive RAM(MRAM), and ferroelectric RAM(FeRAM) has been explored for better performance and energy efficiency on neural networks applications. However, CIM based on a single-type device suffers a variety of non-ideal metrics to reach the simultaneous optimal accuracy, density, and energy efficiency. This work presents equivalent-ideal CIM(Eq-CIM), a monolithic 3D(M3D) IGZO-RRAM-SRAM integrated architecture for robust and efficient compute-in-memory enabling equivalent-ideal device metrics. To overcome the non-ideality(variation, endurance, temperature, etc.) of the single-type devices, system-technology co-optimization(STCO) is performed. This work highlights the non-ideality-aware functionality breakdown for robust high accuracy and simultaneous high density/efficiency, by utilizing 2T0C IGZO for temporal activation storage, RRAM for high-density weight storage, and SRAM for accurate CIM. Device-to-algorithm variation transfer is applied to analyze the system-level accuracy. We benchmark Eq-CIM architecture on CIFAR-10/ImageNet, with 5.06× storage density and 5.05×/2.45× area/energy efficiency compared with single-type-device-based CIM, and high robustness(<0.27% accuracy loss) from-40℃ to 120℃.

关键词： compute-in-memory (CIM) monolithic 3D RRAM IGZO 3D-stack simulation

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Development and verification of the higher-order mode neutron flux calculation code HARMONY2.0

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nuclear Science and Techniques 2025年第1期36卷 207-225页

作者： Er-Pin Zhang Zi-Ning Ni Nian-Biao Deng Jin-Sen Xie Yong Liu Tao Yu School of nuclear Science and Technology University of South ChinaHengyang 421000China Key Laboratory of Advanced nuclear Energy Design and Safety Ministry of EducationHengyang 421000China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

Higher-order modes of the neutron diffusion/transport equation can be used to study the temporal behavior of nuclear reactors and can be applied in modal analysis, transient analysis, and online monitoring of the reactor core. Both the deterministic method and the Monte Carlo(MC) method can be used to solve the higher-order modes. However, MC method, compared to the deterministic method, faces challenges in terms of computational efficiency and α mode calculation stability, whereas the deterministic method encounters issues arising from homogenization-related geometric and energy spectra *** on the higher-order mode diffusion calculation code HARMONY, we developed a new higher-order mode calculation code, HARMONY2.0, which retains the functionality of computing λ and α higher-order modes from HARMONY1.0, but enhances the ability to treat complex geometries and arbitrary energy spectra using the MC-deterministic hybrid two-step strategy. In HARMONY2.0, the mesh homogenized multigroup constants were obtained using OpenMC in the first step,and higher-order modes were then calculated with the mesh homogenized core diffusion model using the implicitly restarted Arnoldi method(IRAM), which was also adopted in the HARMONY1.0 code. In addition, to improve the calculation efficiency, particularly in large higher-order modes, event-driven parallelization/domain decomposition methods are embedded in the HARMONY2.0 code to accelerate the inner iteration of λ∕α mode using OpenMP. Furthermore, the higher-order modes of complex geometric models, such as Hoogenboom and ATR reactors for λ mode and the MUSE-4 experiment facility for the prompt α mode, were computed using diffusion theory.

关键词： Neutron diffusion equation Higher-order modes Global homogenization Two-step method Domain

Yb:Sc_(2)O_(3) Transparent Ceramics Fabricated from Co-precipitated Nano-powders:Microstructure and Optical Property

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无机材料学报 2025年第2期40卷 215-224页

作者： YE Junhao ZHOU Zhenzhen HU Chen WANG Yanbin JING Yanqiu LI Tingsong CHENG Ziqiu WU Junlin IVANOV Maxim HRENIAK Dariusz LI Jiang Transparent Ceramics Research Center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 201899China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Center of Excellence for Photoconversion Vinča Institute of Nuclear SciencesNational Institute of the Republic of SerbiaUniversity of Belgrade11001 BelgradeSerbia institute of Electrophysics Ural Branch Russian Academy of SciencesEkaterinburg 620016Russia institute of Low Temperature and Structure Research Polish Academy of SciencesWroclaw 326109Poland

Sc_(2)O_(3),as a host for solid-state laser gain materials,has advantage of high thermal conductivity and easy matching with activating ions,which is promising in high-power laser ***,Yb-doped Sc_(2)O_(3) ceramics have been fabricated at very high sintering temperatures,but their optical quality and sintering process still need further *** this work,5%Yb:Sc_(2)O_(3)(in mass)nano-powders were obtained by co-precipitation,and then transparent ceramics were fabricated by vacuum pre-sintering and hot isostatic pressing(HIP)*** cubic Yb:Sc_(2)O_(3) nano-powders with good dispersity and an average crystallite of 29 nm were *** of pre-sintering temperatures(1500-1700℃)on densification process,microstructure changes,and optical transmittance of Yb:Sc_(2)O_(3) ceramics was *** data revealed that all samples have a uniform microstructure,while the average grain sizes increase with the increase of the sintering ***,the optimum in-line transmittance of Yb:Sc_(2)O_(3) ceramics,pre-sintered at 1550℃after HIP post-treatment,reaches 78.1%(theoretical value of 80%)at 1100 *** properties of the Yb:Sc_(2)O_(3) ceramics reveal that the minimum population inversion parameterβ2 and the luminescence decay time of 5%Yb:Sc_(2)O_(3) ceramics are 0.041 and 0.49 ms,respectively,which demonstrate that the optical quality of the Yb:Sc_(2)O_(3) has been ***,their best vacuum sintering temperature can be controlled down to a lower temperature(1550℃).In conclusion,Yb:Sc_(2)O_(3) nano-powders are successfully synthesized by co-precipitation method,and good optical quality transparent ceramics are fabricated by vacuum pre-sintering at 1550℃and HIP post-treatment.

关键词： nano-powder Yb:Sc_(2)O_(3) transparent ceramic hot isostatic pressing optical property