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Static and dynamic evolution of CO adsorption onγ-U(100)surface with different levels of Mo doping using DFT and AIMD calculations

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Nuclear Science and Techniques 2023年第9期34卷 142-154页

作者： Jun-Wei li Wei-Min Jia Chong liu Sha-Sha Lv Jin-Tao Wang zheng-cao li Key Lab of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Xi’an Research Institute of High-Technology Xi’an 710025China Key Laboratory of Beam Technology(MOE) College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

Alloys of uranium and molybdenum are considered as the future of nuclear fuel and defense ***,surface corrosion is a fundamental problem in practical applications and *** this study,the static and dynamic evolution of carbon monoxide(CO)adsorption and dissociation onγ-U(100)surface with different Mo doping levels was investigated based on density functional theory and ab initio molecular *** the static calculation phase,parameters,such as adsorption energy,configuration,and Bader charge,were evaluated at all adsorption ***,the time-dependent behavior of CO molecule adsorption were investigated at the most favorable *** minimum energy paths for CO molecu-lar dissociation and atom migration were investigated using the transition state search *** results demonstrated that the CO on the uranium surface mainly manifests as chemical adsorption before dissociation of the CO *** CO molecule exhibited a tendency to rotate and tilt upright ***,it is difficult for CO adsorption on the surface in one of the configurations with CO molecule in vertical direction but oxygen(O)is closer to the *** charge illustrates that the charge transfers from slab atoms to the 2π*antibonding orbital of CO molecule and particularly occurs in carbon(C)*** time is less than 100 fs for the adsorptions that forms embryos with tilt upright in dynamics *** density of states elucidates that the overlapping hybridization of C and O 2p orbitals is mainly formed via the d orbitals of uranium and molybdenum(Mo)atoms in the dissociation and re-adsorption of CO *** conclusion,Mo doping of the surface can decelerate the adsorption and dissociation of CO molecules.A Mo-doped surface,created through ion injection,enhanced the resistance to uranium-induced surface corrosion.

关键词： Adsorption and dissociation Uranium CO molecule Density functional theory Ab initio molecular dynamics

Experimental study on the oxidation behavior and microstructural evolution of NG-CT-10 and NG-CT-20 nuclear graphite

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Nuclear Science and Techniques 2019年第11期30卷 139-148页

作者： Wei Lu Ming-Yang li Xiao-Wei li Xin-Xin Wu li-Bin Sun zheng-cao li Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Collaborative Innovation Center of Advanced Nuclear Energy TechnologyInstitute of Nuclear and New Energy TechnologyTsinghua UniversityBeijing 100084China State Key Laboratory of New Ceramics and Fine Processing Key Laboratory of Advance Materials(MOE)School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China

NG-CT-10 and NG-CT-20 are newly developed grades of nuclear-grade graphite from *** this study,their oxidation behaviors were experimentally investigated using thermal gravimetric *** evolution before and after oxidation was investigated using scanning electron microscope,mercury intrusion,and Raman *** apparent activation energy of NG-CT-10 nuclear graphite is 161.4 kJ/mol in a reaction temperature range of 550–700℃and that of NG-CT-20 is 153.5 kJ/mol in a temperature range of 550–650℃.The activation energy in the inner diffusion control regime is approximately half that in the kinetics control *** high temperatures,the binder phase is preferentially oxidized over the filler particles and small pores are generated in the *** new large or deep pores are generated on the graphite *** can diffuse along the boundaries of filler particles and through the binder phase,but cannot diffuse into the spaces between the nanocrystallites in the filler *** particles are oxidized starting at their outer surfaces,and the sizes of nanocrystallites do not decrease following oxidation.

关键词： Nuclear graphite Oxidation NG-CT-10 NG-CT-20 Activation energy

Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density

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Nuclear Science and Techniques 2024年第5期35卷 74-84页

作者： Sheng-Jie Du Xiu-Xia li Yang Tian Yuan-Yuan liu Ke Jia Zhong-zheng Tang Jian-Ping Cheng Zhi Deng Yu-Lan li zheng-cao li Sha-Sha Lv College of Nuclear Science and Technology Joint Laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment Key Laboratory of Beam Technology of Ministry of Education Beijing Normal UniversityBeijing Normal UniversityBeijing 100875China Joint Research Center Nuctech Company LimitedBeijing 100084China Department of Engineering Physics Key Laboratory of Particle&Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy *** surface passivation of HPGe has become crucial for achieving an extremely low energy *** this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface *** calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface *** on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio *** microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state *** mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关键词： Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density

Evolution of helium bubbles in nickel-based alloy by post-implantation annealing

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Chinese Physics B 2021年第8期30卷 55-60页

作者： Rui Zhu Qin Zhou li Shi li-Bin Sun Xin-Xin Wu Sha-Sha Lv zheng-cao li Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials(Ministry of Education) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Beam Technology Ministry of EducationCollege of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

Nickel-based alloys have been considered as candidate structural materials used in generation IV nuclear reactors serving at high *** the present study,alloy 617 was irradiated with 180-keV helium ions to a fluence of 3.6×10^(17) ions/cm^(2) at room *** the cross-section transmission electron microscopy(TEM)image,numerous over-pressurized helium bubbles in spherical shape are observed with the actual concentration profile a little deeper than the SRIM predicted ***-implantation annealing was conducted at 700℃for 2 h to investigate the bubble *** long-range migration of helium bubbles occurred during the annealing process,which makes the bubbles of the peak region transform into a faceted shape as *** the coarsening mechanism of helium bubbles at different depths is discussed and related to the migration and coalescence(MC)*** the diffusion of nickel atoms slowed down by the alloy elements,the migration and coalescence of bubbles are suppressed in alloy 617,leading to a better helium irradiation resistance.

关键词： helium bubble coarsening mechanism nickel-based alloy

OKMC simulation of vacancy-enhanced Cu solute segregation affected by temperature/irradiation in the Fe–Cu system

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Nuclear Science and Techniques 2022年第11期33卷 158-169页

作者： Zi-Qin Shen Jie Gao Sha-Sha Lv liang Chen Dong-Yue Chen De-Sheng Ai zheng-cao li Key Lab of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Nuclear and New Energy Institute Tsinghua UniversityBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Beam Technology Ministry of EducationCollege of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Nuclear Engineering and Management The University of TokyoTokyo 113-8656Japan

The effects of annealing and irradiation on the evolution of Cu clusters in a-Fe are investigated using object kinetic Monte Carlo *** our model,vacancies act as carriers for chemical species via thermally activated diffusion jumps,thus playing an important role in solute *** the end of the Cu cluster evolution,the simulations of the average radius and number density of the clusters are consistent with the experimental data,which indicates that the proposed simulation model is applicable and *** the simulation of the annealing process,it is found that the evolution of the cluster size roughly follows the 1/2 time power law with the increase in radius during the growth phase and the 1/3 time power law during the coarsening *** addition,the main difference between neutron and ion irradiation is the growth and evolution process of the copper-vacancy *** aggregation of vacancy clusters under ion irradiation suppresses the migration and coarsening of the clusters,which ultimately leads to a smaller average radius of the copper *** proposed simulation model can supplement experimental analyses and provide a detailed evolution mechanism of vacancy-enhanced precipitation,thereby providing a foundation for other elemental precipitation research.

关键词： Object kinetic Monte Carlo Irradiation effect Solute segregation Reactor pressure vessel

Corrosion of New Zirconium Claddings in 500 ℃/10.3 MPa Steam: Effects of Alloying and Metallography

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Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 981-994页

作者： Jing-Jing liao Zhong-Bo Yang Shao-Yu Qiu Qian Peng zheng-cao li Ming-Sheng Zhou Hong liu Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610213China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China

With the aim of improving corrosion resistance of rod cladding for in-service and accident conditions,six new zirconium alloys(named N1-N6)have been *** contents of Sn and Nb were optimized for better behavior at high-temperature pressurized water,and Fe,Cr,V,Cu or Mo elements were added to the alloys to adjust the corrosion behavioi\The current work focused on the rapid corrosion behavior in 500℃/10.3 MPa steam for up to 1960 h,aiming to test the corrosion resistance at high *** structure of matrix and properties of second-phase particles(SPPs)were characterized to find the main differences among these *** the six alloys exhibited better corrosion resistance than N36,and NI was shown to have the best performance.A careful analysis of the corrosion kinetics curves revealed that Cr was beneficial for severe *** Fe,Cr,V,Cu or Mo aggregated into SPPs with diiferent concentrations and *** was demonstrated to be the main reason for different corrosion *** to good processing control,all alloys had a uniform structure and a uniform distribution of *** for N4,N6 and N36,the existing of large-size SPPs(450 nm)might be a contributing factor of the relatively poor corrosion resistance.

关键词： New zirconium cladding Corrosion behavior Alloying elements Metallography Second-phase particles

Building li-S batteries with enhanced temperature adaptability via a redox-active COF-based barrier-trapping electrocatalyst

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Journal of Energy Chemistry 2025年第2期101卷 702-712页

作者： Jie Xu Acheng Zhu Zhangyu zheng Yiming Qi Yuwen Cheng Yongjie cao Bo Peng lianbo Ma Yonggang Wang School of Materials Science and Engineering Key Laboratory of Efficient Conversion and Solid-state Storage of Hydrogen & Electricity of Anhui Province Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials of Ministry of Education Anhui University of Technology Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Institute of New Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Fudan University

Covalent organic frameworks（COFs） are promising materials for mitigating polysulfide shuttling in lithium-sulfur（li-S） batteries,but enhancing their ability to convert polysulfides across a wide temperature range remains a challenge,Herein,we introduce a redox-active COF（RaCOF） that functions as both a physical barrier and a kinetic enhancer to improve the temperature adaptability of li-S batteries,The RaCOF constructed from redox-active anthraquinone units accelerates polysulfide conversion kinetics through reversible C=O/C-Oli transformations within a voltage range of 1,7 to 2.8 V（***+/li）,optimizing sulfur redox reactions in ether-based *** conventional COFs,RaCOF provides bidentate trapping of polysulfides,increasing binding energy and facilitating more effective polysulfide ***-situ XRD and ToF-SIMS analyses confirm that RaCOF enhances polysulfide adsorption and promotes the transformation of lithium sulfide（li2S）,leading to better sulfur cathode ***,RaCOF-modified li-S batteries demonstrate low self-discharge（4.0% decay over a 7-day rest）,excellent wide-temperature performance（stable from-10 to+60℃）,and high-rate cycling stability（94% capacity retention over 500 cycles at 5.0 C）.This work offers valuable insights for designing COF structures aimed at achieving temperature-adaptive performance in rechargeable batteries.

关键词： Covalent organic framework lithium-sulfur batteries Redox-active property Wide-temperature adaptability

Antibiotic exposure alters the honeybee gut microbiota and may interfere with the honeybee behavioral caste transition

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INSECT SCIENCE 2025年第1期32卷 260-276页

作者： Zhang, Zijing Mu, Xiaohuan cao, Qina Zhai, Yifan zheng, li liu, Yan zheng, Hao Zhang, Xue Hebei Normal Univ Coll Life Sci Hebei Collaborat Innovat Ctr Ecoenvironm Hebei Key Lab Anim Physiol Biochem & Mol Biol Shijiazhuang Peoples R China China Agr Univ Coll Food Sci & Nutr Engn Beijing Peoples R China Shandong Acad Agr Sci Inst Plant Protect Jinan Peoples R China Minist Agr & Rural Affairs Key Lab Nat Enemies Insects Jinan Peoples R China China Agr Univ Coll Plant Protect Dept Entomol Beijing Peoples R China

Behavioral division is essential for the sustainability and reproduction of honeybee populations. While accumulating evidence has documented that antibiotic exposure interferes with bee behavioral divisions, how the gut microbiome, host physiology, and genetic regulation are implicated in this process remains understudied. Here, by constructing single-cohort colonies, we validated that the gut microbiota varied in composition between age-matched nurse and forager bees. Perturbing the gut microbiota with a low dose of antibiotic retained the gut bacterial size, but the structure of the microbial community continuously diverged from the control group after antibiotic treatment. Fewer foragers were observed in the antibiotic groups in the field experiment. A combinatorial effect of decreased gut metabolic gene repertoires, reduced brain neurotransmitter titers, and downregulated brain immune genes could potentially be related to behavioral tasks transition delay. This work indicates that the disturbance to both the gut microbiome and host physiologies after antibiotic exposure may have implications on social behavior development, highlighting the need for further research focusing on antibiotic pollution threatening the honeybee population's health.

关键词： antibiotic resistance Apis mellifera behavioral development immune genes

Synergistic enhancement of ion/electron transport by ultrafine nanoparticles and graphene in li2FeTiO4/C/G nanofibers for symmetric li-ion batteries

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Journal of Energy Chemistry 2025年第02期101卷 42-51页

作者： Wenjie Ma Yakun Tang Yue Zhang Xiaohui li Lang liu Xueting Wang Yuliang cao State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources Key Laboratory of Energy Materials Chemistry Ministry of Education College of Chemistry Xinjiang University College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University

Low-cost Fe-based disordered rock salt（DRX） li2FeTiO4is capable of providing high capacity(295 mA h g-1) by redox activity of cations(Fe2+/Fe4+and Ti3+/Ti4+) and anionic ***,DRX structures lack transport channels for ions and electrons,resulting in sluggish kinetics,poor electrochemical activity,and ***,graphene conductive carbon network permeated li2FeTiO4（LFT/C/G） nanofibers are successfully prepared by a facile sol-gel assisted electrospinning *** li2FeTiO4nanoparticles（2 nm） and one-dimensional（1D） structure provide abu ndant active sites and unobstructed diffu sion channels,accelerating ion *** addition,introducing graphene reduces the band gap and li+diffusion barrier and improves the dynamic properties of li2FeTiO4,thus achieving a relatively mild interfacial reaction and reversible redox *** expected,the LFT/C/1.0G cathode delivers a remarkable discharge capacity(238.5 mA h g-1),high energy density(508.8 Wh kg-1),and excellent rate capability(51.2 mA hg-1at 1.0 A g-1).Besides,the LFT/C/1.0G anode also displays a high capacity(514.5 mA h g-1at 500 mA g-1) and a remarkable rate capability(243.9 mA h g-1at 8 A g-1).Moreover,the full batteries based on the LFT/C/1.0G symmetric electrode demonstrate a reversible capacity of 117.0 mA h g-1after 100 cycles at 50 mA *** study presents useful insights into developing cost-effective DRX cathodes with durable and fast lithium storage.

关键词： 1D structure Disordered rock salt li2FeTiO4 Graphene lithium-ion battery electrode Rapid ion/electron transport