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篠原 佑也*; 岩下 拓哉*; 中西 真大*; Liu, Y.*; Cooper, V. R.*; 古府 麻衣子*; 楡井 真実; Dmowski, W.*; Hickner, M. A.*; 江上 毅*
Journal of Physical Chemistry B, 129(47), p.12330 - 12337, 2025/11
被引用回数:0 パーセンタイル:0.00(Biophysics)Enhancing proton transport in polymer electrolytes is crucial for advancing next-generation solid-state batteries, yet our understanding of proton conductivity in nonaqueous environments remains limited due to a lack of atomic-scale insights. In this study, we investigated the atomic-scale dynamics of 1,2,3-triazole, a small molecule capable of dynamic hydrogen bonding, as a model system for proton hopping in nonaqueous environments. Using the real-space correlation function determined by the double Fourier transformation of inelastic neutron scattering spectra, we identified that the self-motion of protons and intermolecular dynamics occur on comparable time scales. Furthermore, we observed that the activation energy associated with the intermolecular dynamics matches the energy barrier for molecular rotations determined through Density Functional Theory calculations. These findings underscore the importance of controlling molecular dynamics at the atomic scale to control proton transport. Additionally, we demonstrated that intermolecular dynamics in systems involving protons can be studied using inelastic neutron scattering even without deuteration, thereby providing a broader avenue for studying atomic-scale dynamics in soft matter systems.
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:6 パーセンタイル:81.24(Multidisciplinary Sciences)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
被引用回数:5 パーセンタイル:81.47(Multidisciplinary Sciences)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.
Cho, S. H.*; Cho, S. W.*; Lv, Z.*; 関根 由莉奈; Liu, S.*; Zhou, M.*; Nuxoll, R. F.*; Kanatzidis, E. E.*; Ghaffari, R.*; Kim, D.*; et al.
Lab on a Chip, 25(7), p.1647 - 1655, 2025/04
被引用回数:14 パーセンタイル:98.90(Biochemical Research Methods)アミノ酸は体内のタンパク質合成と代謝プロセスに不可欠な物質である。本研究では、運動中の汗からのアミノ酸損失について定量的に調べることを目的とした。汗中のアミノ酸含有量をリアルタイムで分析するため、測定のための技術基盤としてウェアラブルなマイクロ流体システムを構築した。定量分析を実現するため、ウェアラブルデバイスに蛍光アッセイを組み込み、さらにスマートフォンベースの画像化技術を統合させたシステムを開発した。
Liu, R.*; 中村 充孝; 蒲沢 和也*; Lu, X.*
Chinese Physics Letters, 41(6), p.067401_1 - 067401_7, 2024/08
被引用回数:4 パーセンタイル:47.75(Physics, Multidisciplinary)Antiferromagnetic spin fluctuation is regarded as the leading driving force for electron pairing in high-
superconductors. Here, we use inelastic neutron scattering (INS) to investigate the symmetry and in-plane wave-vector dependence of low-energy spin excitations in uniaxial-strain detwinned FeSe. The low-energy spin excitations (
10 meV) appear mainly at
= (
1, 0) in the superconducting state (
9 K) and the nematic state (
90 K), confirming the constant C
rotational symmetry and ruling out the C
mode at
3 meV reported in a prior INS study. Moreover, our results reveal an isotropic spin resonance in the superconducting state, which is consistent with the 
wave pairing symmetry. At slightly higher energy, low-energy spin excitations become highly anisotropic.
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
被引用回数:11 パーセンタイル:92.19(Nuclear Science & Technology)In the Best-Estimate Plus Uncertainty (BEPU) framework, the use of best-estimate code requires to go through a Verification, Validation and Uncertainty Quantification process (VVUQ). The relevance of the experimental data in relation to the physical phenomena of interest in the VVUQ process is crucial. Adequacy analysis of selected experimental databases addresses this problem. The outcomes of the analysis can be used to select a subset of relevant experimental data, to encourage designing new experiments or to drop some experiments from a database because of their substantial lack of adequacy. The development of a specific transparent and reproducible approach to analyze the relevance of experimental data for VVUQ still remains open and is the topic of this contribution. In this paper, the concept of adequacy initially introduced in the OECD/NEA SAPIUM (Systematic APproach for model Input Uncertainty quantification Methodology) activity is formalized. It is defined through two key properties, called representativeness and completeness, that allows considering the multifactorial dimension of the adequacy problem. A new systematic approach is then proposed to analyze the adequacy of a set of experimental databases. It relies on the introduction of two sets of criteria to characterize representativeness and completeness and on the use of multi-criteria decision analysis method to perform the analysis. Finally, the approach is applied in the framework of the new OECD/NEA ATRIUM activity which includes a set of practical IUQ exercises in thermal-hydraulics to test the SAPIUM guideline in determining input uncertainties and forward propagating them on an application case. It allows evaluating the adequacy of eight experimental databases coming from the Super Moby-dick, Sozzi-Sutherland and Marviken experiments and identifying the most adequate ones.
Li, X.*; Zhu, R.*; Xin, J.*; Luo, M.*; Shang, S.-L.*; Liu, Z.-K.*; Yin, C.*; 舟越 賢一*; Dippenaar, R. J.*; 肥後 祐司*; et al.
CALPHAD; Computer Coupling of Phase Diagrams and Thermochemistry, 84, p.102641_1 - 102641_6, 2024/03
被引用回数:0 パーセンタイル:0.00(Thermodynamics)The phase transformations and pressure-volume dependencies of the Ti-45Al alloy with respect to pressure have been investigated by means of in-situ observation using multi anvil-type high-pressure devices and synchrotron radiation. Under hydrostatic compression from 0 to 10.1 GPa, about 2.3 vol. % of
transforms continuously to
2. Lattice parameters as well as volume fractions of these two phases have been determined as a function of pressure. Bulk moduli estimated using Birch-Murnaghan's equation of state are 148 GPa for the
phase, 138 GPa for the
2 phase, and 149 GPa for their two-phase mixture of Ti-45Al alloy. First-principles have also applied to investigate bulk moduli of two single phases, and the deviation between calculations and measurements is discussed and attributed to mainly phase transformation. The presently study provides useful insights into thermodynamics of
2 and
phases under high pressure.

Linh, B. D.*; Corsi, A.*; Gillibert, A.*; Obertelli, A.*; Doornenbal, P.*; Barbieri, C.*; Duguet, T.*; G
mez-Ramos, M.*; Holt, J. D.*; Hu, B. S.*; et al.
Physical Review C, 109(3), p.034312_1 - 034312_15, 2024/03
被引用回数:6 パーセンタイル:79.47(Physics, Nuclear)理化学研究所RIビームファクトリーにて中性子過剰核
Arビームからの1中性子ノックアウト反応実験を行い、
Arのエネルギー準位および分光学的因子を導出した。特に、第一励起状態の
への分光学的因子が大きいことから、始状態の
Arの基底状態において中性子が
軌道を多く占めていることがわかった。これは、中性子数32がよい魔法数として知られる
Caとは異なった性質であり、カルシウムからアルゴンへと陽子が2個減ることで閉殻構造が大きく崩れることが明らかになった。
Ca cast doubt on a doubly magic
CaChen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; 角田 佑介*; 大塚 孝治*; 茶園 亮樹*; Hagen, G.*; Holt, J. D.*; et al.
Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08
被引用回数:19 パーセンタイル:92.72(Astronomy & Astrophysics)
Scからの1陽子ノックアウト反応を用いて、
Caと
Caのガンマ崩壊を観測した。
Caでは1456(12)keVの
線遷移が、
Caでは1115(34)keVの遷移が観測された。どちらの遷移も暫定的に
と割り当てられた。有効核子間相互作用をわずかに修正した広い模型空間での殻模型計算では、
準位エネルギー、2中性子分離エネルギー、反応断面積が実験とよく一致し、N=34閉殻の上に新しい殻が形成されていることを裏付けた。その構成要素である
と
軌道はほぼ縮退しており、これは
Caが二重魔法核である可能性を排除し、Ca同位体のドリップラインを
Caあるいはそれ以上にまで広げる可能性がある。
; Bandgap narrowing, metallization, and remarkable enhancement of photoelectric activityFang, Y.*; Kong, L.*; Wang, R.*; Zhang, Z.*; Li, Z.*; Wu, Y.*; Bu, K.*; Liu, X.*; Yan, S.*; 服部 高典; et al.
Materials Today Physics (Internet), 34, p.101083_1 - 101083_7, 2023/05
被引用回数:11 パーセンタイル:66.33(Materials Science, Multidisciplinary)層状ファンデルワールスハライドは、外部圧力に対して特に敏感であるため、目的とする性質を持つ構造にチューンすることが可能となる。一方で、圧力に非常に敏感であるという特性は、同時に目的とする機能の実現に有害な相転移や格子歪みを引き起こす可能性があるためその操作は依然として困難である。この研究では、層状RhI
結晶が持つ極めて弱い層間結合と高い機能可変性を観察した。5GPaという適度な圧力をかけると圧力誘起相転移が起こり、積層構造に変化が現れた。驚くべきことに、この相転移は、圧力に対してほぼ直線的なバンドギャップ減少という傾向に影響を与えなかった。また、より高い圧力では、1.3eVの赤方偏移というかなり大きな調整幅を伴う金属相が観測された。さらに、RhI
のキャリア濃度は30GPaで4桁増加し、光電流は7.8GPaで5桁増加することが確認された。これらの結果は、ファンデルワールスハライドの層状構造という特異な特徴を生かした探索、調整、理解のための新たな機会を創出し、原子レベルの薄さを持つマテリアルバイデザインに基づく将来のデバイスとして有望である。
Liu, S.*; Yang, D. S.*; Wang, S.*; Luan, H.*; 関根 由莉奈; Model, J. B.*; Aranyosi, A. J.*; Ghaffari, R.*; Rogers, J. A.*
EcoMat (Internet), 5(1), p.e12270_1 - e12270_18, 2023/01
被引用回数:58 パーセンタイル:93.07(Chemistry, Physical)発汗量やバイオマーカーの非侵襲的でin situモニタリング技術は、人間の生理学的状態,健康、およびパフォーマンスに関するリアルタイムの洞察を取得するために重要である。最近、様々なウェアラブル型のマイクロ流体システムが開発されているが、ほとんどは使い捨てとして設計されおり、廃棄物問題への懸念がある。本研究では、発汗量の測定、バイオマーカーの比色分析など、あらゆる機能を備えた生分解性マイクロ流体システムを通じて、廃棄物問題を解決する材料と成形技術を確立した。本技術で利用する材料は、自然の土壌環境または産業用堆肥施設での微生物の酵素作用によって完全に分解した。構成材料、製造手順、組み立てプロセス、および完成したデバイスの詳細な特性評価により、従来のデバイスに匹敵する、またはそれよりも優れた性能パラメータが明らかになった。実際の利用試験により、これらのデバイスが身体活動および熱曝露中の発汗速度、発汗量、pH、および塩化物濃度の正確な測定値を取得可能であることが明らかとなった。
island of inversion; First study of low-lying bound excited states in
V and
VElekes, Z.*; Juh
sz, M. M.*; Sohler, D.*; Sieja, K.*; 吉田 数貴; 緒方 一介*; Doornenbal, P.*; Obertelli, A.*; Achouri, N. L.*; 馬場 秀忠*; et al.
Physical Review C, 106(6), p.064321_1 - 064321_10, 2022/12
被引用回数:5 パーセンタイル:49.87(Physics, Nuclear)
Vと
Vの低励起準位構造を初めて探索した。
Vについては中性子ノックアウト反応と陽子非弾性散乱が、
Vについては中性子ノックアウト反応データが得られた。
Vについては4つ、
Vについては5つの新たな遷移が確認された。Lenzi-Nowacki-Poves-Sieja (LNPS)相互作用に基づく殻模型計算との比較によって、それぞれの同位体について確認されたガンマ線のうち3つが、first 11/2
状態とfirst 9/2
状態からの崩壊と決定された。
Vについては、(
,
)非弾性散乱断面積は四重極変形と十六重極変形を想定したチャネル結合法により解析されたが、十六重極変形の影響により、明確に反転の島に属するとは決定できなかった。
neutron orbital and the
shell closure in
CaEnciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; 緒方 一介*; Poves, A.*; 吉田 数貴; Achouri, N. L.*; 馬場 秀忠*; et al.
Physical Review Letters, 129(26), p.262501_1 - 262501_7, 2022/12
被引用回数:28 パーセンタイル:87.98(Physics, Multidisciplinary)
230MeV/nucleonでの
Caからの中性子ノックアウト反応が
線分光と行われ、
と
軌道からの中性子ノックアウト反応の運動量分布が測定された。断面積は
の閉殻と整合し、Ca同位体での
と
閉殻と同程度に強い閉殻であることが確認された。運動量分布の分析から
と
軌道の平均二乗根半径の差は0.61(23)fmと決定され、これはmodified-shell-modelによる予言の0.7fmと整合した。これは、中性子過剰なCa同位体での
軌道半径が大きいことが、中性子数にしたがって線形的に荷電半径が増える意外な現象の原因であることを示唆している。
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:53 パーセンタイル:95.37(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 Na
BaCo(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:67 パーセンタイル:97.61(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.
Liu, B.*; Feng, R.*; Busch, M.*; Wang, S.*; Wu, H.*; Liu, P.*; Gu, J.*; Bahadoran, A.*; 松村 大樹; 辻 卓也; et al.
ACS Nano, 16(9), p.14121 - 14133, 2022/09
被引用回数:133 パーセンタイル:98.68(Chemistry, Multidisciplinary)Pt single-atom materials possess an ideal atom economy but suffer from limited intrinsic activity and side reaction of producing H
O
in catalyzing the oxygen reduction reaction (ORR). Here, we demonstrate that anchoring platinum alloys on single-atom Pt-decorated carbon (Pt- SAC) surmounts their inherent deficiencies, thereby enabling a complete four-electron ORR pathway catalysis with high efficiency and durability. Pt
Co@Pt-SAC demonstrates an exceptional mass and specific activities 1 order of magnitude higher than those of commercial Pt/C. They are durable throughout 50000 cycles, showing only a 10 mV decay in halfwave potential. The superior durability is attributed to the shielding effect of the Pt-SAC coating, which significantly mitigates the dissolution of Pt
Co cores.
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.
Ca; Spectroscopy of
K,
Ca, and
Ca小岩井 拓真*; Wimmer, K.*; Doornenbal, P.*; Obertelli, A.*; Barbieri, C.*; Duguet, T.*; Holt, J. D.*; 宮城 宇志*; Navr
til, P.*; 緒方 一介*; et al.
Physics Letters B, 827, p.136953_1 - 136953_7, 2022/04
被引用回数:11 パーセンタイル:75.64(Astronomy & Astrophysics)中性子過剰核
Caでは、新魔法数34が発見されて以来、その構造を知るために多くの実験がなされてきたが、それを超える中性子過剰核の情報は全く知られてこなかった。本論文では、理化学研究所RIBFにて
K,
Ca,
Caの励起状態から脱励起するガンマ線を初めて観測した結果を報告した。それぞれ1つのガンマ線しか得られなかったものの、
Kおよび
Caのデータは、それぞれ、陽子の
と
軌道間のエネルギー差、中性子の
と
軌道間のエネルギー差を敏感に反映し、両方とも最新の殻模型計算によって200keV程度の精度で再現できることがわかった。また、1粒子状態の程度を特徴づける分光学的因子を実験データと歪曲波インパルス近似による反応計算から求め、その値も殻模型計算の値と矛盾しないことがわかった。
Liu, M.*; Gong, W.; Zheng, R.*; Li, J.*; Zhang, Z.*; Gao, S.*; Ma, C.*; 辻 伸泰*
Acta Materialia, 226, p.117629_1 - 117629_13, 2022/03
被引用回数:122 パーセンタイル:99.50(Materials Science, Multidisciplinary)One hopeful path to realize good comprehensive mechanical properties in metallic materials is to accomplish homogeneous nanocrystalline (NC) or ultrafine grained (UFG) structure with low dislocation density. In this work, high pressure torsion deformation followed by appropriate annealing was performed on 316 stainless steel (SS). For the first time, we successfully obtained NC/UFG 316 SS having uniform microstructures with various average grain sizes ranging from 46 nm to 2.54
m and low dislocation densities. Among the series, an un-precedentedly high yield strength (2.34 GPa) was achieved at the smallest grain size of 46 nm, in which dislocation scarcity induced hardening accounting for 57% of the strength. On the other hand, exceptional strength-ductility synergy with high yield strength (900 MPa) and large uniform elongation (27%) was obtained in the fully recrystallized specimen having the grain size of 0.38
m. The high yield stress and scarcity of dislocation sources in recrystallized UFGs activated stacking faults and deformation twins nucleating from grain boundaries during straining, and their interaction with dislocations allowed for sustainable strain hardening, which also agreed with the plaston concept recently proposed. The multiple deformation modes activated, together with the effective strengthening mechanisms, were responsible for the outstanding comprehensive mechanical performance of the material.
間所 寛; 山下 拓哉; 佐藤 一憲; Gaus-Liu, X.*; Cron, T.*; Fluhrer, B.*; St
ngle, R.*; Wenz, T.*; Vervoortz, M.*; 溝上 伸也
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 16 Pages, 2022/03
Debris and molten pool behavior in the reactor pressure vessel (RPV) lower plenum is a key factor to determine its failure mode, which affects the initial condition of ex-vessel accident progression and the debris characteristics. These are necessary information to accomplish safe decommissioning of the Fukushima Daiichi Nuclear Power Station. After dryout of the solidified debris in the lower plenum, metallic debris is expected to melt prior to the oxide debris due to its lower melting temperature. The lower head failure is likely be originated by the local thermal load attack of a melting debris bed. Numerous experiments have been conducted in the past decades to investigate the homogeneous molten pool behavior with external cooling. However, few experiments address the transient heat transfer of solid-liquid mixture without external cooling. In order to enrich the experimental database of melting and heat transfer process of debris bed consisted of materials with different melting temperatures, LIVE-J1 experiment was conducted using ceramic and nitrate particles as high melting and low melting temperature simulant materials, respectively. The test results showed that debris height decreased gradually as the nitrate particles melt, and molten zone and thermal load on vessel wall were shifted from bottom upwards. Both conductive and convective heat transfer could take place in a solid-liquid mixture pool. These results can support the information from the internal investigations of the primary containment vessel and deepen the understanding of the accident progression.