Extraordinary hardening-by-annealing in bulk ultrafine grained magnesium with ultra-low yttrium addition

Zheng, R.*; Gong, W.; 6 of others*

Acta Materialia, 293, p.121098_1 - 121098_12, 2025/07

https://doi.org/10.1016/j.actamat.2025.121098

A Systematic approach for the adequacy analysis of a set of experimental databases; Application in the framework of the ATRIUM activity

Baccou, J.*; Glantz, T.*; Ghione, A.*; Sargentini, L.*; Fillion, P.*; Damblin, G.*; Sueur, R.*; Iooss, B.*; Fang, J.*; Liu, J.*; et al.

Nuclear Engineering and Design, 421, p.113035_1 - 113035_16, 2024/05

https://doi.org/10.1016/j.nucengdes.2024.113035

observation of twinning and detwinning in AZ31 alloy

Gong, W.; Zheng, R.*; Harjo, S.; Kawasaki, Takuro; Aizawa, Kazuya; Tsuji, Nobuhiro*

Journal of Magnesium and Alloys (Internet), 10(12), p.3418 - 3432, 2022/12

https://doi.org/10.1016/j.jma.2022.02.002

Status of the uncertainty quantification for severe accident sequences of different NPP-designs in the frame of the H-2020 project MUSA

Brumm, S.*; Gabrielli, F.*; Sanchez-Espinoza, V.*; Groudev, P.*; Ou, P.*; Zhang, W.*; Malkhasyan, A.*; Bocanegra, R.*; Herranz, L. E.*; Berda, M.*; et al.

Proceedings of 10th European Review Meeting on Severe Accident Research (ERMSAR 2022) (Internet), 13 Pages, 2022/05

Distance-selected topochemical dehydro-diels-alder reaction of 1,4-Diphenylbutadiyne toward crystalline graphitic nanoribbons

Zhang, P.*; Tang, X.*; Wang, Y.*; Wang, X.*; Gao, D.*; Li, Y.*; Zheng, H.*; Wang, Y.*; Wang, X.*; Fu, R.*; et al.

Journal of the American Chemical Society, 142(41), p.17662 - 17669, 2020/10

https://doi.org/10.1021/jacs.0c08274

Solid-state topochemical polymerization (SSTP) is a promising method to construct functional crystalline polymeric materials, but in contrast to various reactions that happen in solution, only very limited types of SSTP reactions are reported. Diels-Alder (DA) and dehydro-DA (DDA) reactions are textbook reactions for preparing six-membered rings in solution but are scarcely seen in solid-state synthesis. Here, using multiple cutting-edge techniques, we demonstrate that the solid 1,4-diphenylbutadiyne (DPB) undergoes a DDA reaction under 10-20 GPa with the phenyl as the dienophile. The crystal structure at the critical pressure shows that this reaction is "distance-selected". The distance of 3.2 between the phenyl and the phenylethynyl facilitates the DDA reaction, while the distances for other DDA and 1,4-addition reactions are too large to allow the bonding. The obtained products are crystalline armchair graphitic nanoribbons, and hence our studies open a new route to construct the crystalline carbon materials with atomic-scale control.

Signature inversion in the 7/2[503] band of Pt

Li, G. S.*; Zhou, X. H.*; Zhang, Y. H.*; Zheng, Y.*; Liu, M. L.*; Hua, W.*; Zhou, H. B.*; Ding, B.*; Wang, H. X.*; Lei, X. G.*; et al.

Journal of Physics G; Nuclear and Particle Physics, 38(9), p.095105_1 - 095105_9, 2011/09

https://doi.org/10.1088/0954-3899/38/9/095105

High-spin states in Pt have been investigated by means of in beam -ray spectroscopic method at the JAEA tandem facility. Low-spin signature inversion is revealed in the 7/2[503] band. The inversion can be interpreted as a configuration change from the 7/2[503] orbital to the 7/2[514] orbital with increasing spin, which is supported by a theoretical calculation of the semi-classical Donau and Frauendorf approach.

Multi-scale characterization of twinning and detwinning in AZ31 alloy

Gong, W.; Zheng, R.*; Harjo, S.; Kawasaki, Takuro; Aizawa, Kazuya; Tsuji, Nobuhiro*

no journal, , 

Difference in the diffusion behavior of cesium and sodium ions in the interlayer space of montmorillonite using classical molecular dynamics simulations

Hiraguchi, Atsuki; Zheng, X.*; Underwood, T. R.*; Kobayashi, Keita; Yamaguchi, Akiko; Itakura, Mitsuhiro; Machida, Masahiko; Rosso, K. M.*; Bourg, I. C.*; Okumura, Masahiko

no journal, , 

In order to evaluate the long-term safety of geological disposal of high-level radioactive waste, it is necessary to understand the migration behavior of radionuclides in clay minerals used as buffer materials. In this study, the difference in the diffusion behavior of cesium and sodium ions in Na-montmorillonite is analyzed by evaluating the free energy using classical molecular dynamics simulations.

Free energy calculations of cesium ion adsorption to the interlayer of montmorillonites using classical molecular dynamics

Hiraguchi, Atsuki; Zheng, X.*; Underwood, T. R.*; Kobayashi, Keita; Yamaguchi, Akiko; Itakura, Mitsuhiro; Machida, Masahiko; Rosso, K. M.*; Bourg, I. C.*; Okumura, Masahiko

no journal, , 

The migration behavior of radionuclides in clay minerals used as buffer material must be clarified for the long-term safety of geological disposal of high-level radioactive waste. We can investigate diffusion/adsorption behavior of cesium ion and sodium ion in clay minerals and water systems at molecular scale using molecular dynamics simulation on a supercomputing system. In this study, we evaluate the free energy profiles of the cesium and sodium ions adsorption to the montmorillonite interlayer from bulk water in mesopore. We found that the free energies in the interlayer of Na-montmorillonite are smaller than those in the bulk water for the cesium and sodium ions, and the averaged free energy value for cesium in the interlayer is lower than that for sodium. This result shows that cesium ion is more strongly adsorbed to the interlayer of Na-montmorillonite than sodium ion. Moreover, we found differences in the shape of these free energy profiles in the interlayer. The free energy profile for the cesium ion has a spiky structure with many local minimums, although that for the sodium ion is almost uniform. These results suggest that the cesium ion forms the inner-sphere complex at these local minimums and the sodium ion forms the outer-sphere complex. Furthermore, we investigated salinity dependence on the free energy profiles. We confirmed that the affinities of both cations to Na-montmorillonite decrease with increasing salinity, and the adsorption mechanism of these cations does not depend on salinity. In the presentation, we discuss the free energy profiles with different layer charges, interlayer distances, etc.

Large-scale molecular dynamics simulations of cesium diffusion in systems with clay particles and water molecules

Hiraguchi, Atsuki; Zheng, X.*; Underwood, T. R.*; Kobayashi, Keita; Yamaguchi, Akiko; Itakura, Mitsuhiro; Machida, Masahiko; Rosso, K. M.*; Bourg, I. C.*; Okumura, Masahiko

no journal, , 

Understanding the radionuclide diffusion phenomena is crucial for the safe geological disposal of high-level radioactive waste. The diffusion in clay-water systems is particularly important for the performance of the artificial barrier made of bentonite. Numerical simulation is one of the best research methods for understanding the phenomenon at the microscopic level. Recently, large-scale molecular dynamics (MD) simulations of the systems with clay particles and water molecules were realized. In this presentation, we will show numerical simulation results of diffusion of cesium in the large system with MD. Our recent results suggest that cesium is less diffuse than sodium.