Brightening triplet excitons enable high-performance white-light emission in organic small molecules via integrating n-- transitions

Yang, Q.*; Yang, X.*; Wang, Y.*; Fei, Y.*; Li, F.*; Zheng, H.*; Li, K.*; Han, Y.*; Hattori, Takanori; Zhu, P.*; et al.

Nature Communications (Internet), 15, p.7778_1 - 7778_9, 2024/09

https://doi.org/10.1038/s41467-024-52196-7

Luminescent materials that simultaneously embody bright singlet and triplet excitons hold great potential in optoelectronics, signage, and information encryption. However, achieving high-performance white-light emission is severely hampered by their inherent unbalanced contribution of fluorescence and phosphorescence. Herein, we address this challenge by pressure treatment engineering via hydrogen bonding cooperativity effect to realize the mixture of n-- transitions, where the triplet state emission was boosted from 7% to 40% in isophthalic acid (IPA). A superior white-light emission based on hybrid fluorescence and phosphorescence was harvested in pressure-treated IPA, and the photoluminescence quantum yield was increased to 75% from the initial 19% (blue-light emission). In-situ high-pressure IR spectra, X ray diffraction, and neutron diffraction reveal continuous strengthening of the hydrogen bonds with the increase of pressure. Furthermore, this enhanced hydrogen bond is retained down to the ambient conditions after pressure treatment, awarding the targeted IPA efficient intersystem crossing for balanced singlet/triplet excitons population and resulting in efficient white-light emission. This work not only proposes a route for brightening triplet states in organic small molecule, but also regulates the ratio of singlet and triplet excitons to construct high-performance white-light emission.

Microscopic insights of the extraordinary work-hardening due to phase transformation

Ma, Y.*; Naeem, M.*; Zhu, L.*; He, H.*; Sun, X.*; Yang, Z.*; He, F.*; Harjo, S.; Kawasaki, Takuro; Wang, X.-L.*

Acta Materialia, 270, p.119822_1 - 119822_13, 2024/05

https://doi.org/10.1016/j.actamat.2024.119822

Microstructure and plasticity evolution during Lders deformation in an Fe-5Mn-0.1C medium-Mn steel

Koyama, Motomichi*; Yamashita, Takayuki*; Morooka, Satoshi; Sawaguchi, Takahiro*; Yang, Z.*; Hojo, Tomohiko*; Kawasaki, Takuro; Harjo, S.

Tetsu To Hagane, 110(3), p.197 - 204, 2024/02

https://doi.org/10.2355/tetsutohagane.TETSU-2023-038

Validation of the Be ground-state molecular structure using Be()He triple differential reaction cross-section measurements

Li, P. J.*; Beaumel, D.*; Lee, J.*; Assi, M.*; Chen, S.*; Franchoo, S.*; Gibelin, J.*; Hammache, F.*; Harada, T.*; Kanada-En'yo, Yoshiko*; et al.

Physical Review Letters, 131(21), p.212501_1 - 212501_7, 2023/11

https://doi.org/10.1103/PhysRevLett.131.212501

The cluster structure of the neutron-rich isotope Be has been probed via the () reaction. The triple differential cross-section was extracted and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using the Tohsaki-Horiuchi-Schuck-Rpke wave function and the wave function deduced from Antisymmetrized Molecular Dynamics calculations. The remarkable agreement between calculated and measured cross-sections in both shape and magnitude validates the description of the Be ground-state as a rather compact nuclear molecule.

Observation of a threshold cusp at the threshold in the mass spectrum with decays

Yang, S.*; Tanida, Kiyoshi; Belle Collaboration*; 196 of others*

Physical Review D, 108(3), p.L031104_1 - L031104_6, 2023/08

https://doi.org/10.1103/PhysRevD.108.L031104

The Investigations of the -wave states combining quark model and lattice QCD in the coupled channel framework

Yang, Z.*; Wang, G.-J.*; Wu, J.-J.*; Oka, Makoto; Zhu, S.-L.*

Journal of High Energy Physics (Internet), 2023(1), p.058_1 - 058_19, 2023/01

https://doi.org/10.1007/JHEP01(2023)058

Combining the quark model, the quark-pair-creation mechanism and interaction, we have investigated the near-threshold -wave states in the framework of the Hamiltonian effective field theory. With the heavy quark flavor symmetry, all the parameters are determined in the sector by fitting the lattice data. The masses of the bottom-strange partners of the and are predicted, which are well consistent with the lattice QCD simulation. The two -wave states are the mixtures of the bare core and component. Moreover, we find a crossing point between the energy levels with and without the interaction Hamiltonian in the finite volume spectrum in the case, which corresponds to a CDD (Castillejo-Dalitz-Dyson) zero in the -matrix of the scattering. This CDD zero will help deepen the insights of the near-threshold states and can be examined by future lattice calculation.

Microstructure and plasticity evolution during Lders deformation in an Fe-5Mn-0.1C medium-Mn steel

Koyama, Motomichi*; Yamashita, Takayuki*; Morooka, Satoshi; Sawaguchi, Takahiro*; Yang, Z.*; Hojo, Tomohiko*; Kawasaki, Takuro; Harjo, S.

ISIJ International, 62(10), p.2036 - 2042, 2022/10

https://doi.org/10.2355/isijinternational.ISIJINT-2021-510

CSNI leak-before-break benchmark; Summary of phase 1

Tregoning, R.*; Wallace, J.*; Bouydo, A.*; Costa-Garrido, O.*; Dillstrm, P.*; Duan, X.*; Heckmann, K.*; Kim, Y.-B.*; Kim, Y.*; Kurth-Twombly, E.*; et al.

Transactions of the 26th International Conference on Structural Mechanics in Reactor Technology (SMiRT-26) (Internet), 11 Pages, 2022/07

Fourteen organizations, representing eleven countries, participated in a leak-before-break (LBB) benchmark exercise that compared results from analyses among participating countries and identified the effects of weld residual stress (WRS) and crack morphology on crack opening displacement (COD), critical bending moment (CBM), and leak rate (LR) results. The participants determined whether the initial problem would meet their country's LBB acceptance criteria and then evaluated the effects of crack morphology and WRS for a prescribed crack size, geometry and loading. Six out of fourteen participants indicated that the initial problem met their LBB requirements. In the follow-on tasks, differences among the participant's CBM predictions were principally due to the material properties used in the analysis while the type of failure model chosen contributed much less. Most of the differences in the LR predictions were directly attributable to differences among the COD models, but a portion was attributable to the treatment of crack face pressure (CFP). The benchmark identified several aspects of an LBB analysis that could support a more realistic evaluation.

Formation of clusters in dilute neutron-rich matter

Tanaka, Junki*; Yang, Z.*; Typel, S.*; Adachi, Satoshi*; Bai, S.*; van Beek, P.*; Beaumel, D.*; Fujikawa, Yuki*; Han, J.*; Heil, S.*; et al.

Science, 371(6526), p.260 - 264, 2021/01

https://doi.org/10.1126/science.abe4688

By employing quasi-free -cluster-knockout reactions, we obtained direct experimental evidence for the formation of clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between -cluster formation and the neutron skin.

Spallation and fragmentation cross sections for 168 MeV/nucleon Xe ions on proton, deuteron, and carbon targets

Sun, X. H.*; Wang, H.*; Otsu, Hideaki*; Sakurai, Hiroyoshi*; Ahn, D. S.*; Aikawa, Masayuki*; Fukuda, Naoki*; Isobe, Tadaaki*; Kawakami, Shunsuke*; Koyama, Shumpei*; et al.

Physical Review C, 101(6), p.064623_1 - 064623_12, 2020/06

https://doi.org/10.1103/PhysRevC.101.064623

The spallation and fragmentation reactions of Xe induced by proton, deuteron and carbon at 168 MeV/nucleon were studied at RIKEN Radioactive Isotope Beam Factory via the inverse kinematics technique. The cross sections of the lighter products are larger in the carbon-induced reactions due to the higher total kinetic energy of carbon. The energy dependence was investigated by comparing the newly obtained data with previous results obtained at higher reaction energies. The experimental data were compared with the results of SPACS, EPAX, PHITS and DEURACS calculations. These data serve as benchmarks for the model calculations.