Dual nanoprecipitation and nanoscale chemical heterogeneity in a secondary hardening steel for ultrahigh strength and large uniform elongation

Wang, S.*; Wang, J.*; Zhang, S.*; Wei, D.*; Chen, Y.*; Rong, X.*; Gong, W.; Harjo, S.; Liu, X.*; Jiao, Z.*; et al.

Journal of Materials Science & Technology, 185, p.245 - 258, 2024/06

https://doi.org/10.1016/j.jmst.2023.10.048

A Quantitative method of eutectic reaction study between boron carbide and stainless steel

Hong, Z.*; Pellegrini, M.*; Erkan, N.*; Liao, H.*; Yang, H.*; Yamano, Hidemasa; Okamoto, Koji*

Annals of Nuclear Energy, 180, p.109462_1 - 109462_9, 2023/01

https://doi.org/10.1016/j.anucene.2022.109462

A series of experiments were conducted using BC material and SUS304 tubes as a simulant of the real control rods. Reaction rate constant data in the 1450K-1500K range were obtained, and are consistent with the reference values. The reaction layer microstructure observation and the associated chemical composition analysis were also carried onto the experiment samples.

New insight of Mn(III) in -MnO for peroxymonosulfate activation reaction; Via direct electron transfer or via free radical reactions

Ouyang, H.*; Wu, C.*; Qiu, X.*; Tanaka, Kazuya; Onuki, Toshihiko*; Yu, Q.*

Environmental Research, 217, p.114874_1 - 114874_10, 2023/01

https://doi.org/10.1016/j.envres.2022.114874

Phase transition and chemical reactivity of 1H-tetrazole under high pressure up to 100 GPa

Gao, D.*; Tang, X.*; Wang, X.*; Yang, X.*; Zhang, P.*; Che, G.*; Han, J.*; Hattori, Takanori; Wang, Y.*; Dong, X.*; et al.

Physical Chemistry Chemical Physics, 23(35), p.19503 - 19510, 2021/09

https://doi.org/10.1039/D1CP02913D

Pressure-induced phase transition and polymerization of nitrogen-rich molecules are widely focused due to its extreme importance for the development of green high energy density materials. Here, we present a study of the phase transition and chemical reaction of 1H-tetrazole up to 100 GPa by using Raman, IR, X-ray diffraction, neutron diffraction techniques and theoretical calculation. A phase transition above 2.6 GPa was identified and the high-pressure structure was determined with one molecule in a unit cell. The 1H-tetrazole polymerizes reversibly below 100 GPa, probably through a carbon-nitrogen bonding instead of nitrogen-nitrogen bonding. Our studies updated the structure model of the high pressure phase of 1H-tetrazole, and presented the possible intermolecular bonding route for the first time, which gives new insights to understand the phase transition and chemical reaction of nitrogen-rich compounds, and benefit for designing new high energy density materials.

Electromagnetic transitions of the singly charmed baryons with spin 3/2

Kim, J.-Y.*; Kim, H.-C.*; Yang, G.-S.*; Oka, Makoto

Physical Review D, 103(7), p.074025_1 - 074025_21, 2021/04

AA2020-0757.pdf:1.74MB

https://doi.org/10.1103/PhysRevD.103.074025

We investigate the electromagnetic transitions of the singly charmed baryons with spin 3/2, based on a pion mean-field approach, also known as the chiral quark-soliton model, taking into account the rotational corrections and the effects of flavor SU(3) symmetry breaking. We examine the valence- and sea-quark contributions to the electromagnetic transition form factors and find that the quadrupole form factors of the sea-quark contributions dominate over those of the valence-quark ones in the smaller region, whereas the sea quarks only provide marginal contributions to the magnetic dipole transition form factors of the baryon sextet with spin 3/2. The effects of the flavor SU(3) symmetry breaking are in general very small except for the forbidden transition by -spin symmetry. We also discuss the widths of the radiative decays for the baryon sextet with spin 3/2, comparing the present results with those from other works.

Mechanism of hardening and damage initiation in oxygen embrittlement of body-centred-cubic niobium

Yang, P.-J.*; Li, Q.-J.*; Tsuru, Tomohito; Ogata, Shigenobu*; Zhang, J.-W.*; Sheng, H.-W.*; Shan, Z.-W.*; Sha, G.*; Han, W.-Z.*; Li, J.*; et al.

Acta Materialia, 168, p.331 - 342, 2019/04

https://doi.org/10.1016/j.actamat.2019.02.030

Body-centred-cubic metallic materials, such as niobium (Nb) and other refractory metals, are prone to embrittlement due to low levels of oxygen solutes. The mechanisms responsible for the oxygen-induced rampant hardening and damage are unclear. Here we illustrate that screw dislocations moving through a random repulsive force field imposed by impurity oxygen interstitials readily form cross-kinks and emit excess vacancies in Nb. The vacancies bind strongly with oxygen and screw dislocation in a three-body fashion, rendering dislocation motion difficult and hence pronounced dislocation storage and hardening. This leads to unusually high strain hardening rates and fast breeding of nano-cavities that underlie damage and failure.

Scaling of memories and crossover in glassy magnets

Samarakoon, A. M.*; Takahashi, Mitsuru*; Zhang, D.*; Yang, J.*; Katayama, Naoyuki*; Sinclair, R.*; Zhou, H. D.*; Diallo, S. O.*; Ehlers, G.*; Tennant, D. A.*; et al.

Scientific Reports (Internet), 7(1), p.12053_1 - 12053_8, 2017/09

AA2017-0448.pdf:3.45MB

https://doi.org/10.1038/s41598-017-12187-9

Synthesis, structure, and pressure-induced polymerization of LiFe(CN) accompanied with enhanced conductivity

Li, K.*; Zheng, H.*; Hattori, Takanori; Sano, Asami; Tulk, C. A.*; Molaison, J.*; Feygenson, M.*; Ivanov, I. N.*; Yang, W.*; Mao, H.-K.*

Inorganic Chemistry, 54(23), p.11276 - 11282, 2015/12

https://doi.org/10.1021/acs.inorgchem.5b01851

Pressure-induced polymerization of triple bonds would produce conductive conjugated double bonds. To find a metal cyanide with a low polymerization pressure, anhydrous LiFe(CN) is synthesized and its crystal structure is determined. The irreversible bonding between the CN can be realized by use of the industrial apparatus. The conductivity is enhanced by more than 3 orders of magnitude, which makes the polymerized LiFe(CN) a potential cathode material for rechargeable lithium batteries.

Extremely long quasiparticle spin lifetimes in superconducting aluminum using MgO tunnel spin injectors

Yang, H.*; Yang, S.-H.*; Takahashi, Saburo; Maekawa, Sadamichi; Parkin, S.*

Nature Materials, 9(7), p.586 - 593, 2010/07

https://doi.org/10.1038/nmat2781

There has been an intense search in recent years for long-lived spin-polarized carriers for spintronic and quantum-computing devices. Here we report that spin polarized quasi-particles in superconducting aluminum layers have surprisingly long spin-lifetimes, nearly a million times longer than in their normal state. The lifetime is determined from the suppression of the aluminum's superconductivity resulting from the accumulation of spin polarized carriers in the aluminum layer using tunnel spin injectors. A Hanle effect, observed in the presence of small in-plane orthogonal fields, is shown to be quantitatively consistent with the presence of long-lived spin polarized quasi-particles. Our experiments show that the superconducting state can be significantly modified by small electric currents, much smaller than the critical current, which is potentially useful for devices involving superconducting qubits.

Plasma-surface interaction, scrape-off layer and divertor physics; Implications for ITER

Lipschultz, B.*; Asakura, Nobuyuki; Bonnin, X.*; Coster, D. P.*; Counsell, G.*; Doerner, R.*; Dux, R.*; Federici, G.*; Fenstermacher, M. E.*; Fundamenski, W.*; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2006/html/node23.htm#3799

The work of the ITPA SOL/divertor group is reviewed. The high-n nature of ELMs has been elucidated and new measurements have determined that they carry 10-20% of the ELM energy to the far SOL with implications for ITER limiters and the upper divertor. Analysis of ELM measurements imply that the ELM continuously loses energy as it travels across the SOL. The prediction of ITER divertor disruption power loads have been reduced as a result of finding that the divertor footprint broadens during the thermal quench and that the plasma can lose up to 80% of its thermal energy before the thermal quench (not for VDEs or ITBs). Disruption mitigation through massive gas puffing has been successful at reducing divertor heat loads but estimates of the effect on the main chamber walls indicate 10s of kG of Be would be melted/mitigation. Long-pulse studies have shown that the fraction of injected gas that can be recovered after a discharge decreases with discharge length. The use of mixed materials gives rise to a number of potential processes.