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.

Gradient residual stress and fatigue life prediction of induction hardened carbon steel S38C axles; Experiment and simulation

Qin, T. Y.*; Hu, F. F.*; Xu, P. G.; Zhang, H.*; Zhou, L.*; Ao, N.*; Su, Y. H.; Shobu, Takahisa; Wu, S. C.*

International Journal of Fatigue, 185, p.108336_1 - 108336_13, 2024/08

https://doi.org/10.1016/j.ijfatigue.2024.108336

Spectral evidence for Dirac spinons in a kagome lattice antiferromagnet

Zeng, Z.*; Zhou, C.*; Zhou, H.*; Han, L.*; Chi, R.*; Li, K.*; Kofu, Maiko; Nakajima, Kenji; Wei, Y.*; Zhang, W.*; et al.

Nature Physics, 20(7), p.1097 - 1102, 2024/07

https://doi.org/10.1038/s41567-024-02495-z

3D-printed epidermal sweat microfluidic systems with integrated microcuvettes for precise spectroscopic and fluorometric biochemical assays

Yang, D. S.*; Wu, Y.*; Kanatzidis, E. E.*; Avila, R.*; Zhou, M.*; Bai, Y.*; Chen, S.*; Sekine, Yurina; Kim, J.*; Deng, Y.*; et al.

Materials Horizons, 10(11), p.4992 - 5003, 2023/09

https://doi.org/10.1039/D3MH00876B

This paper presents a set of findings that enhances the performance of these systems through the use of microfluidic networks, integrated valves and microscale optical cuvettes formed by three-dimensional printing in hard/soft hybrid materials systems, for accurate spectroscopic and fluorometric assays. Field studies demonstrate the capability of these microcuvette systems to evaluate the concentrations of copper, chloride, and glucose in sweat, along with the sweat pH, with laboratory grade accuracy and sensitivity.

Fatigue crack non-propagation behavior of a gradient steel structure from induction hardened railway axles

Zhang, H.*; Wu, S. C.*; Ao, N.*; Zhang, J. W.*; Li, H.*; Zhou, L.*; Xu, P. G.; Su, Y. H.

International Journal of Fatigue, 166, p.107296_1 - 107296_11, 2023/01

https://doi.org/10.1016/j.ijfatigue.2022.107296

A Safer preprocessing system for analyzing dissolved organic radiocarbon in seawater

Otosaka, Shigeyoshi*; Jeon, H.*; Hou, Y.*; Watanabe, Takahiro; Aze, Takahiro*; Miyairi, Yosuke*; Yokoyama, Yusuke*; Ogawa, Hiroshi*

Nuclear Instruments and Methods in Physics Research B, 527, p.1 - 6, 2022/09

https://doi.org/10.1016/j.nimb.2022.07.003

The measurement the radiocarbon of dissolved organic matter (DOC) in seawater can provide information about a timescale of the dynamics of dissolved organic matter as well as about its sources in the ocean. Due to the low DOC concentration in seawater, in spite of the development of accelerator mass spectrometry, a relatively large volume of seawater (1 L) is required for that analysis. In addition, complicated processing such as UV irradiation that emits high heat is required. In this study, we have developed a safer and easier method to analyze DOC in seawater than the conventional method. A particularly significant change was the adoption of a low-pressure mercury lamp in the decomposition system, which enabled direct decomposition of organic matter at lower temperatures. We also propose a method to quantitatively evaluate the accuracy of this system by analyzing simulated seawater consists of a soluble reference material of organic matter and sodium chloride. This method is expected to be applied not only to carbon isotope ratio analysis but also to analysis of trace elements and isotopes of various dissolved organic substances.

Structure of an aqueous RbCl solution in the gigapascal pressure range by neutron diffraction combined with empirical potential structure refinement modeling

Zhang, W. Q.*; Yamaguchi, Toshio*; Fang, C. H.*; Yoshida, Koji*; Zhou, Y. Q.*; Zhu, F. Y.*; Machida, Shinichi*; Hattori, Takanori; Li, W.*

Journal of Molecular Liquids, 348, p.118080_1 - 118080_11, 2022/02

https://doi.org/10.1016/j.molliq.2021.118080

The ion hydration and association and hydrogen-bonded water structure in an aqueous 3 mol/kg RbCl solution were investigated at 298 K/0.1 MPa, 298 K/1 GPa, 523 K/1 GPa, and 523 K/4 GPa by neutron diffraction combined with EPSR methods. The second hydration layer of Rb and Cl becomes evident under elevated pressure and temperature conditions. The average oxygen coordination number of Rb (Cl) in the first hydration layer increases from 6.3 (5.9) ambient pressure to 8.9 (9.1) at 4 GPa, while decreasing coordination distance from 0.290 nm (0.322 nm) to 0.288 nm (0.314 nm). The orientation of the water dipole in the first solvation shell of Rb and a central water molecule is sensitive to pressure, but that in the first solvation shell of Cl does not change very much. The number of contact-ion pairs Rb-Cl decreases with elevated temperature and increases with elevated pressure. Water molecules are closely packed, and the tetrahedral hydrogen-bonded network of water molecules no longer exists in extreme conditions.

Spin Hall magnetoresistance in Pt/CrO/YIG structure

Qi, J.*; Hou, D.*; Chen, Y.*; Saito, Eiji; Jin, X.*

Journal of Magnetism and Magnetic Materials, 534, p.167980_1 - 167980_6, 2021/09

https://doi.org/10.1016/j.jmmm.2021.167980

Enhancement of fatigue resistance by overload-induced deformation twinning in a CoCrFeMnNi high-entropy alloy

Lam, T.-N.*; Lee, S. Y.*; Tsou, N.-T.*; Chou, H.-S.*; Lai, B.-H.*; Chang, Y.-J.*; Feng, R.*; Kawasaki, Takuro; Harjo, S.; Liaw, P. K.*; et al.

Acta Materialia, 201, p.412 - 424, 2020/12

https://doi.org/10.1016/j.actamat.2020.10.016

The Joint evaluated fission and fusion nuclear data library, JEFF-3.3

Plompen, A. J. M.*; Cabellos, O.*; De Saint Jean, C.*; Fleming, M.*; Algora, A.*; Angelone, M.*; Archier, P.*; Bauge, E.*; Bersillon, O.*; Blokhin, A.*; et al.

European Physical Journal A, 56(7), p.181_1 - 181_108, 2020/07

https://doi.org/10.1140/epja/s10050-020-00141-9

The Joint Evaluated Fission and Fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides U, U and Pu, on Am and Na, Ni, Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yileds, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 is excellent for a wide range of nuclear technology applications, in particular nuclear energy.