Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Zhao, X.*; Zhang, Z.*; 服部 高典; Wang, J.*; Li, L.*; Jia, Y.*; Li, W.*; Xue, J.*; Fan, X.*; Song, R.*; et al.
Nature Communications (Internet), 16, p.7713_1 - 7713_8, 2025/08
被引用回数：0 パーセンタイル：0.00熱効果は、固体状態の冷凍技術の一つの解決策の基盤を成すもので、通常は固体状態の相転移付近で発生し、冷凍温度範囲が限定されている。ここでは、前例のない概念である「全温度帯バロカロリック効果」を導入し実現する。すなわち、KPF
において77.5Kから300Kの極めて広い温度範囲(潜在的に4Kまで)で観測される顕著なバカカロリック効果である。この温度範囲は、一般的な室温、液体窒素、液体水素、液体ヘリウムの冷却領域をカバーしている。直接測定されたバーカロリック断熱温度変化は、250MPaの圧力を解放した際に、室温で12K、77.5Kで2.5Kに達する。この効果は、圧力依存性の中性子粉末回折、ラマン散乱解析、第一原理計算により示されるように、菱面体高圧相への持続的な相転移に起因する。構造的不安定性を考慮した熱力学的エネルギーランドスケープを記述する。この独自の全温度帯バロカロリック効果は、従来の多段式シナリオを超えた、高度に適用可能な固体状態冷凍技術への新たなアプローチを提供する。
Liu, R.*; Stone, M. B.*; Gao, S.*; 中村 充孝; 蒲沢 和也*; Krajewska, A.*; Walker, H. C.*; Cheng, P.*; Yu, R.*; Si, Q.*; et al.
Nature Communications (Internet), 16, p.5212_1 - 5212_8, 2025/06
The quantum-disordered state in FeSe, intertwined with superconductivity and nematicity, has been a research focus in iron-based superconductors. Temperature-dependent differences between Q= (1, 0) and (0, 1) spin excitations above the structural transition unambiguously reveals the nematic quantum disordered state. Comparison with NaFeAs suggests the Neel excitations originate from enhanced 3dxy orbital correlations. Modeling the stripe dispersions using a J1-K-J2 Heisenberg Hamiltonian, we establish a spininteraction phase diagram, positioning FeSe near a crossover regime between the antiferroquadrupolar, Neel, and stripe orders. Our results provide key insights into themicroscopic spin interactions and their role in the intertwined orders in iron-based superconductors.
Zhu, L.*; He, H.*; Naeem, M.*; Sun, X.*; Qi, J.*; Liu, P.*; Harjo, S.; 中島 健次; Li, B.*; Wang, X.-L.*
Physical Review Letters, 133(12), p.126701_1 - 126701_6, 2024/09
被引用回数：4 パーセンタイル：72.86(Physics, Multidisciplinary)It has long been suspected that magnetism could play a vital role in the phase stability of multi- component high-entropy alloys. However, the nature of the magnetic order, if any, has remained elusive. Here, by using elastic and inelastic neutron scattering, we demonstrate evidence of antiferromagnetic order below 
80 K and strong spin fluctuations persisting to room temperature in a single-phase face-centered cubic (fcc) CrMnFeCoNi high-entropy alloy. Despite the chemical complexity, the magnetic structure in CrMnFeCoNi can be described as 
-Mn-like, with the magnetic moments confined in alternating (001) planes and pointing toward the 
111
direction. Combined with first-principles calculation results, it is shown that the antiferromagnetic order and spin fluctuations help stabilized the fcc phase in CrMnFeCoNi high-entropy alloy.
山本 風海; 守屋 克洋; 沖田 英史; 山田 逸平; 地村 幹; Saha, P. K.; 菖蒲田 義博; 田村 文彦; 山本 昌亘; 森下 卓俊; et al.
Journal of Neutron Research, 26(2-3), p.59 - 67, 2024/01
J-PARC Linacおよび3GeVシンクロトロン(RCS)は、1MWの大強度ビームを中性子実験施設および主リングシンクロトロンに供給するために運転している。これまで進めてきたビーム調整および機器改良により、当初想定よりもはるかに低いビームロス量で1MWのビーム運転を行うことが出来ている。現在のビーム出力はビームロスではなくRCSの高周波加速空胴の電源容量によって制限されている。近年、RCSグループではより少ない消費電力でビームを加速することのできる新しい構造の加速空胴の開発に成功した。この空胴によって、利用運転中に加速空胴で消費される電力を大幅に削減することが出来、さらに1MW以上の大出力での運転も可能となる。これまでの試験結果から、RCSの加速空胴を全て新しい物へ更新すれば、1.5MW以上の大出力も可能となる事が判っている。今後、中性子利用および主リングシンクロトロンの更なる成果創出のため、2MWを目標にRCSで必要な改良について検討を行った。その結果、高周波空胴の更新以外にも、高周波増幅器の増強やビームモニタの増強が必要であることが判ったため、今後順次更新を進める。
Zhang, A.*; Deng, K.*; Sheng, J.*; Liu, P.*; Kumar, S.*; 島田 賢也*; Jiang, Z.*; Liu, Z.*; Shen, D.*; Li, J.*; et al.
Chinese Physics Letters, 40(12), p.126101_1 - 126101_8, 2023/12
被引用回数：12 パーセンタイル：84.13(Physics, Multidisciplinary)In a Dirac semimetal, the massless Dirac fermion has zero chirality, leading to surface states connected adiabatically to a topologically trivial surface state as well as vanishing anomalous Hall effect. Recently, itis predicted that in the nonrelativistic limit of certain collinear antiferromagnets, there exists a type of chiral "Dirac-like" fermion, whose dispersion manifests four-fold degenerate crossing points formed by spin-degenerate linear bands, with topologically protected Fermi arcs. Here, by combining with neutron diffraction and first-principles calculations, we suggest a multidomain collinear antiferromagnetic configuration, rendering the existence of the Fermi-arc surface states induced by chiral Dirac-like fermions.
Ao, N.*; Zhang, H.*; Xu, H. H.*; Wu, S. C.*; Liu, D.*; 徐 平光; Su, Y. H.; Kang, Q. H.*; Kang, G. Z.*
Engineering Fracture Mechanics, 281, p.109166_1 - 109166_14, 2023/03
被引用回数：14 パーセンタイル：81.21(Mechanics)Considering the complex service environments that high-speed railway axles are subjected to, the fatigue crack growth (FCG) behavior of a structurally gradient axle steel with different pre-crack depths both in air and corrosive medium was investigated at a frequency of 5 Hz. The results indicated that in the high 
region, FCG rate was dramatically accelerated by corrosion, but the gap narrows as decreased. The accelerated corrosion FCG rate was a comprehensive result of the acceleration effect of the anodic dissolution, hydrogen-enhanced localized plasticity and the retardation effect of corrosion-induced crack-tip blunting. Despite the fact that the corrosion resistance gradually decreased as the pre-crack depth increased, the FCG rate in the corrosive medium gradually decreased. This was because fatigue loading played a more important role than corrosion in accelerating the corrosion FCG rate.
Chen, J.*; 山本 慧; Zhang, J.*; Ma, J.*; Wang, H.*; Sun, Y.*; Chen, M.*; Liu, S.*; Gao, P.*; Yu, D.*; et al.
Physical Review Applied (Internet), 19(2), p.024046_1 - 024046_9, 2023/02
被引用回数：6 パーセンタイル：55.96(Physics, Applied)Coherent coupling in magnon based hybrid system has many potential applications in quantum information processing. Magnons can propagate in magnetically ordered materials without any motion of electrons, offering a unique method to build low-power-consumption devices and information channels free of heat dissipation. In this article, we demonstrate the coherent propagation of hybridized modes between spin waves and Love surface acoustic waves in a multiferroic BiFeO
and ferromagnetic La
Sr
MnO based heterostructure. The magneto-elastic coupling enables a giant enhancement of strength of the hybridized mode by a factor of 26 compared to that of the pure spin waves. A short wavelength down to 250 nm is demonstrated for the hybridized mode, which is desirable for nanoscale acousto-magnonic applications. Our combined experimental and theoretical analyses represent an important step towards the coherent control in hybrid magnonics, which may inspire the study of magnon-phonon hybrid systems for coherent information processing and manipulation.
and 
shell gap for Ti and V by the first high-precision multireflection time-of-flight mass measurements at BigRIPS-SLOWRI飯村 俊*; Rosenbusch, M.*; 高峰 愛子*; 角田 佑介*; 和田 道治*; Chen, S.*; Hou, D. S.*; Xian, W.*; 石山 博恒*; Yan, S.*; et al.
Physical Review Letters, 130(1), p.012501_1 - 012501_6, 2023/01
被引用回数：15 パーセンタイル：88.16(Physics, Multidisciplinary)The atomic masses of 
Sc, 
Ti, and 
V have been determined using the high-precision multireflection time-of-flight technique. The radioisotopes have been produced at RIKEN's Radioactive Isotope Beam Factory (RIBF) and delivered to the novel designed gas cell and multireflection system, which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For Ti and V, the mass uncertainties have been reduced down to the order of 10 keV, shedding new light on the shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species 
Ti and 
V. With the new precision achieved, we reveal the nonexistence of the empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied 
p
orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the d
and g
orbits and compare the results with conventional shell model calculations, which exclude the g and the d orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at 
.
Liu, X. J.*; 徐 平光; 城 鮎美*; Zhang, S. Y.*; 菖蒲 敬久; 行武 栄太郎*; 秋田 貢一*; Zolotoyabko, E.*; Liss, K.-D.*
Journal of Materials Science, 57(46), p.21446 - 21459, 2022/12
被引用回数：5 パーセンタイル：29.66(Materials Science, Multidisciplinary)In situ time/temperature-resolved synchrotron high-energy X-ray diffraction is applied to study heat-mediated structural changes and phase transformations in rolled sheets of AZ91 and AZ31 magnesium alloys. Azimuthal diffraction intensities along the Debye-Scherrer rings (AT-plots) are used to obtain information on grain recovery and recrystallization temperatures as well as temperature-assisted grain rotations. The azimuthally integrated diffraction intensities, plotted as functions of the scattering vector (QT-plots), provide vital data on the temperature-dependent lattice parameters of the Mg/Al matrix and intermetallic precipitates, as well as on the evolution of the precipitates' volume fraction. It was found that in AZ31, the main precipitates are of the AlMn type, which is rather stable in the investigated temperature range (up to 773 K). In contrast, in AZ91, the major intermetallic precipitates, Al
Mg
, undergo complete dissolution above 600 K. It is caused by the enhanced diffusion of Al into the Mg/Al matrix, which according to the Al-Mg phase diagram, can adopt more Al at elevated temperatures. This diffusion is revealed by the proportional diminishing of the matrix lattice parameter (chemical strain), allowing us to quantify the Al content in the matrix. Fast temperature-dependent manipulation with intermetallic content in the Mg/Al alloy can, in principle, be used for controlling its mechanical properties.
Zhang, J.*; Kuang, L.*; Mou, Z.*; 近藤 俊明*; 小嵐 淳; 安藤 麻里子; Li, Y.*; Tang, X.*; Wang, Y.-P.*; Pe
uelas, J.*; et al.
Plant and Soil, 481(1-2), p.349 - 365, 2022/12
被引用回数：13 パーセンタイル：75.91(Agronomy)Soil warming effects on soil organic carbon (SOC) decomposition and stabilization are highly variable, and the underlying mechanisms are poorly understood. In this study, concentration, stability (dissolved, particle and mineral-associated SOC), and source (plant-derived and microbial-derived) of SOC, soil microbial community composition, and enzyme activities were studied in a 10-year soil warming field experiment in an East Asian monsoon forest. The results showed that 10-year soil warming significantly enhanced SOC in the top 0-10 cm soil. The increased SOC induced by warming was mainly derived from plants with lignin markers, accompanied by a decrease in microbial-derived SOC. This highlights an urgent need for a better understanding of how the contrasting effects of plant- and microbial-derived C mediate the response of the SOC pool to warming across different biomes.
BaCo(PO
)Sheng, J.*; Wang, L.*; Candini, A.*; Jiang, W.*; Huang, L.*; Xi, B.*; Zhao, J.*; Ge, H.*; Zhao, N.*; Fu, Y.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(51), p.e2211193119_1 - e2211193119_9, 2022/12
被引用回数：37 パーセンタイル：94.71(Multidisciplinary Sciences)Although considerable progress has been made in the theoretical understanding of the low-dimensional frustrated quantum magnets, experimental realizations of a well-established scaling analysis are still scarce. This is particularly true for the two-dimensional antiferromagnetic triangular lattices. Owing to the small exchange strength, the newly discovered compound NaBaCo(PO) provides a rare opportunity for clarifying the quantum criticality in an ideal triangular lattice with quantum spin S=1/2. In addition to the establishment of the complete phase diagrams, the spin Hamiltonian with a negligible interplane interaction has been determined through the spin wave dispersion in the polarized state, which is consistent with the observation of a two-dimensional quantum critical point with the Bose-Einstein condensation of diluted free bosons.
neutron diffraction and electron microscopy studyZheng, R.*; Gong, W.; Du, J.-P.*; Gao, S.*; Liu, M.*; Li, G.*; 川崎 卓郎; Harjo, S.; Ma, C.*; 尾方 成信*; et al.
Acta Materialia, 238, p.118243_1 - 118243_15, 2022/10
被引用回数：46 パーセンタイル：96.60(Materials Science, Multidisciplinary)Grain refinement can lead to the strengthening of metallic materials according to the Hall-Petch relationship. However, our recent results suggested that grain boundary sliding is the dominant deformation mode in bulk ultrafine grained (UFG) pure Mg at room temperature, leading to softening. Here, for the first time, we report that the Hall-Petch strengthening can be regained in bulk UFG pure Mg at cryogenic temperature. At 77K, the UFG pure Mg with a mean grain size of 0.6 
m exhibited ultrahigh tensile yield strength and ultimate tensile strength of 309 MPa and 380 MPa, respectively. Combined neutron diffraction and electron microscopy investigation indicated that residual dislocation structures and deformation twins hardly formed in the UFG specimen during tensile test at 298K. In contrast, fast accumulation of lattice defects and remarkable reorientation were evident at 77K, suggesting that the grain-boundary-mediated process was suppressed and the plastic deformation was dominated by dislocation slip and deformation twinning. In addition, all the pure Mg specimens exhibited pronounced strain hardening at 77 K, which was mainly attributed to the suppressed grain boundary sliding and dynamic recovery. The mean dislocation density and relative fractions of dislocations with various Burgers vectors of the UFG specimen deformed at 77K were determined quantitatively from neutron diffraction data.
isomer in 
Hg and 
(
2) systematics of neutron transitions across the nuclear chartHuang, H.*; Zhang, W. Q.*; Andreyev, A. N.; Liu, Z.*; Seweryniak, D.*; Li, Z. H.*; Guo, C. Y.*; Barzakh, A. E.*; Van Duppen, P.*; Andel, B.*; et al.
Physics Letters B, 833, p.137345_1 - 137345_8, 2022/10
被引用回数：3 パーセンタイル：39.49(Astronomy & Astrophysics)The decay of the 13/2 isomeric state in Hg was observed for the first time following the 
decay of the 13/2 isomer in 
Pb produced in the 
Nd
Cr
reaction. Using - delayed coincidence measurements, the half-life of this isomer was measured to be 290(30) s. This isomer is proposed to deexcite by an unobserved low-energy 
2 transition to the known 9/2
member of a strongly prolate-deformed 7/2[514] band, followed by a 105-keV 1 transition to the bandhead. A lower limit of B(2)
0.018 W.u. was deduced for the unobserved transition. The presumed retardation is proposed to be due to the notable shape change between the initial, nearly spherical, and the final, strongly deformed, states. A similar scenario is also considered for the 13/2 isomer in 
Hg, suggesting both are cases of shape isomers. The B(2) systematics of neutron transitions across the nuclear chart is discussed.
beam at the SNSGorlov, T.*; Aleksandrov, A.*; Cousineau, S.*; Liu, Y.*; Oguz, A. R.*; Kay, M.*; Saha, P. K.
Proceedings of the 2022 North American Particle Accelerator Conference (NAPAC 2022) (Internet), p.702 - 704, 2022/08
The conventional method of H charge-exchange injection by using a solid stripper foil has serious drawbacks such as, a short foil lifetime, unexpected failure and moreover a high residual radiation due to uncontrolled foil scattering beam losses at high-intensity operation. To overcome all those issues, an H stripping by using only lasers or by laser assisted are being extensively studied at J-PARC and the Spallation Neutron Source (SNS) at Oak Ridge, USA, respectively. However, a reduction of the laser power to realize the laser stripping is a common issue at both labs. In this research, different schemes and methods of laser stripping, especially for an effective excitation of the ground state hydrogen atom are considered. Among all methods the most realistic and practical scheme seems to be the sequential excitation scheme by using two types of laser. In this case, a laser power can be reduced to 1/25 as compared to a single step excitation. Due to a lower H energy, a deep UV laser is used at J-PARC. Such a reduction of the laser power is further useful for a realistic implementation.
sp
Hard Rock Laboratory (Sweden)Soler, J. M.*; Meng, S.*; Moreno, L.*; Neretnieks, I.*; Liu, L.*; Kek
linen, P.*; Hokr, M.*; 
ha, J.*; Vete
nk, A.*; Reimitz, D.*; et al.
Geologica Acta, 20(7), 32 Pages, 2022/07
被引用回数：3 パーセンタイル：41.66(Geology)亀裂性岩石中の地下水流動と物質移行のモデル化に関するSKBタスクフォースにおけるTask 9Bは、スウェーデンのエスポ岩盤研究所で実施された原位置長期収着・拡散試験(LTDE-SD)の試験結果のモデル化に焦点をあてたものである。10のモデリングチームによって、異なるモデル概念やコードを用いたモデル化が実施された。モデル化のアプローチは、(1)拡散方程式の解析解、(2)連続多孔質媒体中の数値計算モデル、(3)微細な不均質性(鉱物粒界,微細亀裂の分布等)を考慮した微細構造モデルの大きく3種に分類できる。異なるチームによるモデル化結果から、岩石や亀裂の表面の擾乱影響を含む岩石特性の不均質な分布、微細な亀裂の効果など、様々な異なるモデル概念の比較・評価がなされた。
Soler, J. M.*; Neretnieks, I.*; Moreno, L.*; Liu, L.*; Meng, S.*; Svensson, U.*; Iraola, A.*; Ebrahimi, K.*; Trinchero, P.*; Molinero, J.*; et al.
Nuclear Technology, 208(6), p.1059 - 1073, 2022/06
被引用回数：7 パーセンタイル：58.41(Nuclear Science & Technology)SKBタスクフォースは、亀裂性岩石中の地下水流動と物質移行のモデル化に関する国際フォーラムである。WPDE試験はフィンランドのオンカロ地下施設において実施された片麻岩中のマトリクス拡散試験である。複数の非収着性及び収着性のトレーサーを含む模擬地下水が試錐孔の試験区間に沿って注入された。タスク9Aは、WPDE試験で得られたトレーサー破過曲線に対する予測モデリングを行うことを目的とした。複数のチームが本タスクに参加し、異なるモデル化手法とコードを用いた予測解析を行った。この予測解析の重要な結論は、試錐孔の開口部における地下水流動に関連する分散パラメータにモデル化結果が大きく影響されることである。マトリクス拡散及び収着に関連する破過曲線のテール部に着目すると、異なるチーム間の解析結果の差異は相対的に小さい結果となった。
北垣 徹; 吉田 健太*; Liu, P.*; 菖蒲 敬久
npj Materials Degradation (Internet), 6(1), p.13_1 - 13_8, 2022/02
被引用回数：2 パーセンタイル：10.67(Materials Science, Multidisciplinary)Zircon's degradation due to reactivity with aqueous solutions renders it difficult to read past records. Therefore, the reactive behavior of zircon in various acid-base solutions was examined under normal temperature and pressure conditions. A piece of zircon mineral was immersed in three different solutions: 0.1M HCl (aq), ultrapure water, and 0.1M NaOH (aq). Consequently, the reaction was limited when zircon was immersed in ultrapure water. In the case of the zircon immersed in 0.1M HCl (aq), Zr precipitated on the surface after the dissolution of ZrSiO. In the zircon immersed in 0.1M NaOH (aq), dissolved Zr and Si precipitated on the surface in the early stages. Subsequently, the dissolution of ZrSiO formed a porous layer, and most dissolved Zr precipitated as new zircon crystals.
Wang, X.*; Tang, X.*; Zhang, P.*; Wang, Y.*; Gao, D.*; Liu, J.*; Hui, K.*; Wang, Y.*; Dong, X.*; 服部 高典; et al.
Journal of Physical Chemistry Letters (Internet), 12(50), p.12055 - 12061, 2021/12
被引用回数：17 パーセンタイル：74.65(Chemistry, Physical)置換ポリアセチレンは、ポリアセチレン骨格の化学的安定性,物性,付加機能の向上が期待されるが、その多様性は非常に限られている。今回我々は、固体のアセチレンジカルボン酸に外圧を加えることにより、従来の方法では合成が非常に困難であったトランス-ポリアセチレン骨格上のすべての炭素がカルボキシル基に結合した結晶性のポリ-ジカルボキシルアセチレンができることを報告する。重合は、水素結合を利用したトポケミカル反応であった。このユニークな構造は、カルボニル基の極めて高い含有量とポリアセチレン骨格の高い導電性を組み合わせたもので、リチウムイオン電池(LIB)負極として高い比容量と優れたサイクル/レート性能を示す。我々は、完全に機能化された結晶性ポリアセチレンを紹介し、高分子LIB材料や活性基を多く含む高分子材料合成のために圧力重合が有力な方法であることを提案する。
sp HRL LTDE-SD experimentsSoler, J. M.*; Meng, S.*; Moreno, L.*; Neretnieks, I.*; Liu, L.*; Keklinen, P.*; Hokr, M.*; ha, J.*; Vetenk, A.*; Reimitz, D.*; et al.
SKB TR-20-17, 71 Pages, 2021/07
亀裂性岩石中の地下水流動と物質移行のモデル化に関するSKBタスクフォースにおけるTask 9Bは、スウェーデンのエスポ岩盤研究所で実施された原位置長期収着・拡散試験(LTDE-SD)の試験結果のモデル化に焦点をあてたものである。10のモデリングチームによって、異なるモデル概念やコードを用いたモデル化が実施された。モデル化のアプローチは、(1)拡散方程式の解析解、(2)連続多孔質媒体中の数値計算モデル、(3)微細な不均質性(鉱物粒界,微細亀裂の分布等)を考慮した微細構造モデルの大きく3種に分類できる。異なるチームによるモデル化結果から、岩石や亀裂の表面の擾乱影響を含む岩石特性の不均質な分布、微細な亀裂の効果など、様々な異なるモデル概念の比較・評価がなされた。
beam at J-PARC RCSSaha, P. K.; 原田 寛之; 金正 倫計; 米田 仁紀*; 道根 百合奈*; 渕 葵*; 佐藤 篤*; Liu, Y.*
JPS Conference Proceedings (Internet), 33, p.011025_1 - 011025_7, 2021/03
We proposed and also preparing for a POP (Proof-of-Principle) demonstration of a completely non-destructive H stripping method by using only lasers at J-PARC. To reduce the laser power, which is one of the critical issues in this case, we have studied an extensive manipulations of the H beam as well advanced uses of the lasers in this research. These includes utilizing a dispersion derivative of the H beam to cope with its large momentum spread, while multi-pass laser system to utilize multiple interactions of the H beam with lasers. We have estimated that the laser power can be reduced to more than one order of magnitude by applying a combination of these two methods. The detail simulation and experimental results of the H beam manipulations as well as development status of the multi-pass laser system are presented in this paper.
