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Algorithm for Calculating the Coefficient of Electron Transmission through One- and Two-Dimensional Periodic Nanostructures

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Bulletin of the Russian Academy of Sciences: physics 2024年第12期88卷 1888-1894页

作者： Sadykov, N.R. Skryabin, S.N. Snezhinsky Institute of Physics and Technology National Research Nuclear University Moscow Engineering Physics Institute Snezhinsk456776 Russia

Abstract: A numerical algorithm is obtained for calculating the electron transmission function in an arbitrary potential field in cases of 1D and 2D on the basis of a numerical procedure of searching for the energy levels and eigenwave functions of stationary states. Results are compared to available analytical and numerical solutions. A twisted nanoribbon is investigated as a 2D nanostructure. It is proposed that the obtained results be applied to 2D translation invariant waveguides, in which constants of the propagation guided modes act as energy levels. © Pleiades Publishing, Ltd. 2024.

关键词： Iterative methods

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Alternative Off-Site Power Supply during Extended Station Blackout for Future nuclear Power Plants in Indonesia 7

Alternative Off-Site Power Supply during Extended Station Bl...

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7th Astechnova International Energy Conference, ASTECHNOVA 2023

作者： Hakim, Arief Rahman Saputro, Rakhmat Eko Department of Nuclear Engineering Ulsan National Institute of Science and Technology Korea Republic of Nuclear Engineering Department of Nuclear Engineering and Engineering Physics Universitas Gadjah Mada Indonesia

The study explores the diverse and flexible coping (FLEX) strategy on a conventional large nuclear power plant connected to an alternative off-site power. Indonesia is one of the countries with the highest natural hazards in the world, so the newly-built NPPs are susceptible to station blackout (SBO) accidents one of the highest contributors to the core damage frequency (CDF). The study proposes a dedicated, independent, and direct electrical connection between a pressurized water reactor to a nearby hydropower plant as the alternative off-site power supply during the extended SBO. The study shows that the proposed strategy successfully reduces the SBO frequency by 90% - a net 33% CDF reduction without a major modification to the existing PWR design. © Published under licence by IOP Publishing Ltd.

关键词： Pressurized water reactors

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Internal friction behavior of Ni_(50.5)Mni_(25)Ga_(24.5)alloy with cellular microstructure

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Rare Metals 2023年第5期42卷 1706-1711页

作者： Jun-Yi Liu Jing-Min Wang Cheng-Bao Jiang Hui-Bin Xu Zhi-Song Xiao School of Materials Science and Engineering Beihang UniversityBeijing100191China School of Physics and Nuclear Energy Engineering Beihang UniversityBeijing100191China

Ni_(50.5)Mn_(25)Ga_(24.5)alloy with cellular microstructure was *** effect of the cellular microstructure on the internal friction(IF)behavior associated with martensitic transformation(MT),premartensitic transformation(PMT)and twin boundary motion(TBM)was *** with conventional NiMn-Ga alloys,the temperature span of the IF_(MT)peak is significantly expanded,the IF_(PMT)is weakened,and no IF_(TBM)is *** IF_(MT)and IF_(PMT)in the cellular microstructure exhibit unique frequency dispersion feature which has never been observed in conventional Ni-Mn-Ga *** effect of point defects associated with the cellular microstructure is considered to understand the observed results.

关键词： Martensitic transformations Internal friction Microstructure Point defects

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Prediction of the first 2^(+) states properties for atomic nuclei using light gradient boosting machine

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nuclear Science and Techniques 2025年第2期36卷 95-102页

作者： Hui Liu Xin-Xiang Li Yun Yuan Wen Luo Yi Xu School of Nuclear Science and Technology University of South ChinaHengyang 421001China Extreme Light Infrastructure-Nuclear Physics(ELI-NP) Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering(IFIN-HH)Strada Reactorului 30Buchurest-Magurele077125 IlfovRomania

The first 2^(+)excited states of the nucleus directly reflect the interaction between the shell structure and the nucleus,providing insights into the validity of the shell model and nuclear structure *** the features of the first 2^(+)excited states can be measured for stable nuclei and calculated using nuclear models,significant uncertainty *** study employs a machine learning model based on a light gradient boosting machine(LightGBM)to investigate the first 2^(+)excited ***,the training of the LightGBM algorithm and the prediction of the first 2^(+)properties of 642 nuclei are ***,detailed comparisons of the LightGBM predictions were performed with available experimental data,shell model calculations,and Bayesian neural network *** results revealed that the average difference between the LightGBM predictions and the experimental data was 18 times smaller than that obtained by the shell model and only 70%of the BNN prediction *** Mg,Ca,Kr,Sm,and Pb isotopes as examples,it was also observed that LightGBM can effectively reproduce the magic number mutation caused by shell effects,with the energy being as low as 0.04 MeV due to shape ***,we believe that leveraging LightGBM-based machine learning can profoundly enhance our insights into nuclear structures and provide new avenues for nuclear physics research.

关键词： First 2^(+) state nuclear levels Light gradient boosting machine

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Fabrication and fracture behaviors of the continuous brittle fiber reinforced tungsten composites fabricated via field-assisted sintering technology

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Tungsten 2025年第1期7卷 172-182页

作者： Rui Shu Yi-Ran Mao Jan W. Coenen Alexis Terra Stephan Sch?nen Johann Riesch Christian Linsmeier Christoph Broeckmann Juelich Research Center Institute of Energy and Climate Research Plasma Physics (IEK-4) Partner in the Trilateral Euregio Cluster Institute of Materials Applications in Mechanical Engineering (IWM) RWTH Aachen University Department of Nuclear Engineering & Engineering Physics University of Wisconsin Madison Central Institute of Engineering Electronics and Analytics Engineering and Technology (ZEA-1) Juelich Research Center Max Planck Institute for Plasma Physics Institute of Materials Applications in Mechanical Engineering IWM RWTH Aachen University

Tungsten（W） is a promising candidate material for the plasma-facing components in future fusion ***,it has issues regarding the intrinsic brittleness as well as operational *** fiber reinforced tungsten（W_f/W） composites overcome these issues by using extrinsic toughening *** to neutron irradiation and high-temperature recrystallization during fusion operation,the ductility of the fibers may degrade over a long period of ***,it is necessary to investigate the fracture behavior of W_f/W composites with brittle *** the present work,the tungsten fibers were embrittled by ***,the continuous brittle W_f/W composite with yttrium oxide（Y2O3） interface was fabricated by the field-assisted sintering technology *** microstructure of the prepared W_f/W composites was *** fracture behavior and toughening mechanisms were discussed in detail based on the experimental results of 3-point bending tests and the corresponding finite element *** composites show a pseudo-ductile fracture *** are hindered and deflected by the de-bonded fiber-matrix *** extrinsic toughening mechanisms of interface de-bonding,crack bridging,and fiber pull-out are *** indicates the reinforcement concept still works even though all components in the W_f/W are brittle.

关键词： Interface Fracture behavior Numerical simulation W_f/W composites Field-assisted sintering technology(FAST)

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Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

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nuclear Science and Techniques 2024年第2期35卷 145-159页

作者： Yan-Yan Ding Yang-Bo Nie Yue Zhang Zhi-Jie Hu Qi Zhao Huan-Yu Zhang Kuo-Zhi Xu Shi-Yu Zhang Xin-Yi Pan Chang-Lin Lan Jie Ren Xi-Chao Ruan Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 62100China

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic *** leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight *** samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 *** leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and *** on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were *** results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

关键词： Leakage neutron spectra Uranium D-T neutron source Evaluated nuclear data

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Optimization of Fuel Enrichment and Reactor Core Pitch Dimension in Hydride Microreactor using NSGA-II Method and OpenMC Calculation 7

Optimization of Fuel Enrichment and Reactor Core Pitch Dimen...

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7th Astechnova International Energy Conference, ASTECHNOVA 2023

作者： Gusti, A.R.P. Harto, A.W. Agung, A. Department of Nuclear Engineering and Engineering Physics Universitas Gadjah Mada Yogyakarta Indonesia

This study focuses on the design optimization of a hydride microreactor, aimed at supporting the equitable development of electricity in remote regions of Indonesia. Its compact design, inherent safety properties, and independence from the conventional electric grid make this microreactor concept suitable for electrifying even the most inaccessible areas. Current research investigates various aspects of the hydride microreactor design, employing a standard reactor core pitch dimension of 2.4 cm and fuel enrichment of 12%. It is crucial to operate the reactor using specific concentrations of Gadolinia burnable poison to enable a shutdown in the event of a stuck rod. By optimizing only the pitch dimension and fuel enrichment, the reactor can be simulated relatively quickly without the need for burnup calculations. Ideal configuration aims for lower enrichment, an extended fuel cycle, and a relatively low power peaking factor (PPF). The optimization process utilizes the Non-dominated Sorting Genetic Algorithm - II, with the neutron multiplication factor (keff) and PPF as primary objectives. Fuel cycle and feedback reactivity are the sub-objectives that are used to identify the optimal solution from the Pareto front. The calculation process of keff, PPF, fuel cycle, and feedback reactivity coefficients for specific pitch dimensions and fuel enrichment are done by utilizing the OpenMC Monte Carlo code. The optimal configuration is obtained through four generations of NSGA-II, featuring a reactor core pitch of 2.1 cm and fuel enrichment of 10.4%. This configuration yields a keff value of 1.0712049 and a PPF value of 2,0728 at the Beginning of Life (BOL). Remarkably, this configuration enables safe operation without using burnable poison for a continuous period of 12 years, generating 1 MW of thermal power. Emphasizing the reduction of fissile material is also essential to enhance the inherent safety of the reactor. © Published under licence by IOP Publishing Ltd.

关键词： Reactor shutdowns

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Triple-function Mn regulation of NiFe(oxy)hydroxide for oxygen evolution reaction

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材料科学技术（英文版） 2025年第4期207卷 1-9页

作者： Hui Wan Meng-Yuan Xie Bo Li Jian-Hang Nie Tao Huang Lei Li Jing-Hui Shi Ming-Hua Xian Jia-Rong Huang Wangyu Hu Gui-Fang Huang Fei Gao Wei-Qing Huang Department of Applied Physics School of Physics and ElectronicsHunan UniversityChangsha 410082China School of Materials and Environmental Engineering Changsha UniversityChangsha 410082China Department of Applied Physics School of Physics and ElectronicsHunan UniversityChangsha 410082China College of Materials Science and Engineering Hunan UniversityChangsha 410082China Department of Nuclear Engineering and Radiological Sciences University of MichiganAnn ArborMI 48109USA

Transition metal(oxy)hydroxides are potential oxygen evolution reaction(OER)electrocatalysts;however,simultaneously modulating multiple factors to enhance their performance is a grand ***,we report an incorporating heteroatom strategy via one-step hydrothermal approach to adjust more than one factor of Mn-doped NiFe(oxy)hydroxide(Mn-NiFeOOH/LDH)*** doping regulates heterojunction morphology(reducing nanoparticles and becoming thinner and denser nanosheets),Ni/Fe ratio and valence states(Ni2+,Ni3+,and Ni3+Δ)of Ni *** former could effectively increase surface active sites,and the latter two reduce the content of Fe in the Mnx-NiFeOOH/LDH heterojunction,en-abling more Ni2+convert to Ni3+/3+Δ that have higher intrinsic OER *** a result,the first-rank Mn-NiFeOOH/LDH with ultra-low overpotential of 185 mV@20 mA cm-2 and 296 mV@500 mA cm-2,and the improved OER performance are outdo to those of commercial RuO2 catalyst for ***,the Mn-NiFeOOH/LDH affords the earliest initial potential(1.392 V ***),corresponds to a recorded low overpotential(162 mV).Based on the density functional theory(DFT),Mn dopants can alter intermedi-ate adsorption energy and effectively decrease·OOH's energy *** research exhibits a feasible strategy to design low cost electrocatalysts and provide new possibilities for future industrialization.

关键词： Electrocatalysts Triple-function Heteroatoms adjusting DFT Oxygen evolution reaction

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Recent progress of in-situ characterization of LiNi_(1−x−y)Co_(x)Mn_(y)O_(2) cathodes for lithium metal batteries: A mini review

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Nano Research 2024年第3期17卷 1384-1401页

作者： Huanzhu Lv Xiaoqi Zhu Jun Mei Yuanhua Xia Bin Wang Institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 611731China Chengdu Development Center of Science and Technology China Academy of Engineering PhysicsChengdu 610200China Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics(CAEP)Mianyang 621999China

In the context of the gradual popularity of electric vehicles(EVs),the development of lithium battery systems with high energy density and power density is regarded as the foremost way to improve the range of ***_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathodes have been the focus of researchers due to their high energy density,excellent power performance,and low-temperature ***,the elaboration of the decay mechanism of NCM cathode based on lithium metal batteries(LMBs)is still being restricted to the primary *** the past decades,the development and application of advanced in-situ characterization tools have facilitated researchers'understanding of the internal operation mechanism of batteries during charging and *** this minireview,the latest progress of in-situ observation of the NCM cathode by X-ray diffraction(XRD),fourier transform infrared(FT-IR)spectroscopy,Raman spectroscopy,atomic force microscopy(AFM),transmission electron microscope(TEM),optical microscope,and other characterization tools is *** mechanisms of structural degradation,cathode-electrolyte interfaces(CEIs)composition,and dynamic changes of NCM,electrolyte breakdown,and gas production are ***,based on the existing research progress,the opportunities and challenges for future in-situ characterization technology in the study of the mechanism of LMBs are discussed in ***,the purpose of this minireview is to summarize recent work that focuses on the outstanding application of in-situ characterization techniques in the mechanistic study of LMBs,and pointing the way to the future development of high energy density and power density LMBs systems.

关键词： lithium metal batteries(LMBs) In-situ characterization LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)

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A novel method for simultaneous measurement of^(222)Rn and^(220)Rn progeny concentrations measured by an alpha spectrometer

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nuclear Science and Techniques 2025年第1期36卷 127-139页

作者： Zhong-Kai Fan Jia-Le Sun Hao-Xuan Li Xiang-Ming Cai Hui Yang Shou-Kang Qiu Yan-Liang Tan Jian Shan School of Nuclear Science and Technology University of South ChinaHengyang 421001China College of Physics and Electronic Engineering Hengyang Normal UniversityHengyang 421008China

The accumulation of^(222)Rn and^(220)Rn progeny in poorly ventilated environments poses the risk of natural radiation exposure to the public.A previous study indicated that satisfactory results in determining the^(222)Rn and^(220)Rn progeny concentrations by measuring the total alpha counts at five time intervals within 560 min should be expected only in the case of high progeny concentrations in *** complete the measurement within a relatively short period and adapt it for simultaneous measurements at comparatively lower^(222)Rn and^(220)Rn progeny concentrations,a novel mathematical model was proposed based on the radioactive decay *** model employs a nonlinear fitting method to distinguish nuclides with overlapping spectra by utilizing the alpha particle counts of non-overlapping spectra within consecutive measurement cycles to obtain the concentrations of^(222)Rn and^(220)Rn progeny in *** verification experiments were conducted using an alpha *** experimental results demonstrate that the concentrations of^(222)Rn and^(220)Rn progeny calculated by the new method align more closely with the actual circumstances than those calculated by the total count method,and their relative uncertainties are all within±16%.Furthermore,the measurement time was reduced to 90 min,representing an acceleration of 84%.The improved capability of the new method in distinguishing alpha particles with similar energies emitted from ^(218)Po and^(212)Bi,both approximately 6 MeV,contributed to realizing more accurate *** proposed method has the potential advantage of measuring relatively low concentrations of^(222)Rn and^(220)Rn progeny in air more quickly via air filtration.

关键词： ^(222)Rn ^(220)Rn Progeny concentration Nonlinear fitting method Alpha spectrometer

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