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北條 智彦*; 小山 元道*; 熊井 麦弥*; Zhou, Y.*; 柴山 由樹; 城 鮎美*; 菖蒲 敬久; 齋藤 寛之*; 味戸 沙耶*; 秋山 英二*
ISIJ International, 65(2), p.284 - 296, 2025/02
被引用回数：0Stress and plastic strain distributions and those partitioning behaviors of ferrite and retained austenite were investigated in the medium manganese (Mn) and the transformation-induced plasticity-aided bainitic ferrite (TBF) steels, and the martensitic transformation behaviors of retained austenite during Luders elongation and work hardening were analyzed using synchrotron X-ray diffraction at SPring-8. The stress and plastic strain of retained austenite and volume fraction of retained austenite were remarkably changed during Luders deformation in the medium Mn steel, implying that the medium Mn steel possessed inhomogeneous deformation at the parallel part of the tensile specimen. On the other hand, the distributions of the stress, plastic strain and volume fraction of retained austenite were homogeneous and the homogeneous deformation occurred at the parallel part of the tensile specimen at the plastic deformation regime with work hardening in the medium Mn and TBF steels. The martensitic transformation of retained austenite at uders deformation in the medium Mn steel was possessed owing to the application of high stress and preferential deformation at retained austenite, resulting in a significant increase in the plastic deformation and reduction of stress in the retained austenite. The martensitic transformation of retained austenite at the plastic deformation regime with work hardening was induced by the high dislocation density and newly applied plastic deformation in retained austenite in the medium Mn steel whereas the TBF steel possessed gradual transformation of retained austenite which is applied high tensile stress and moderate plastic deformation.
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, 9 Pages, 2025/00
被引用回数：0 パーセンタイル：0.00(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。
Zhou, W.*; 三輪 修一郎*; 山下 晋; 岡本 孝司*
Progress in Nuclear Energy, 177, p.105441_1 - 105441_17, 2024/12
被引用回数：0 パーセンタイル：0.00(Nuclear Science & Technology)原子力工学や水力工学の分野では、噴流によって引き起こされる空気の巻き込み現象を理解することが重要である。空気巻込みは、原子力システムの重要な安全設計パラメータの1つである。しかしながら、既存研究のほとんどは、気泡の侵入深さを推定するための経験的相関式やカーブフィッティングモデルに依存しており、様々なジェット条件に対する合意された計算原理は存在しない。この問題に対処するため、本研究では、2つの先進的なAIアプローチを開発した。すなわち、空気巻き込みをセグメント化するための改良型YOLOv5と、気泡侵入深さを予測するためのNSGA-III-BPNN法である。改良型YOLOv5は、多様な条件下での空気巻き込み運動とダイナミクスのリアルタイムなセグメンテーションと抽出を可能にし、高いスケーラビリティとロバスト性を実証した。改良型YOLOv5を用いて推定された侵入深度は、従来の経験的相関と比較して高い精度を示し、動的な空気巻き込みパターンに基づく形状レジームを分類するための従来の画像後処理技術よりも効率的である。一般的にビデオや画像データに依存する物体セグメンテーションの限界を克服するために、NSGA-III-BPNN法はYOLOv5よりも高い精度で最大侵入深度を予測する。YOLOv5よりも高い精度で最大侵入深度を予測し、空気巻き込み侵入深度のより効果的な予測モデルを提供する。高度なAI技術を活用することで、この研究は、数値流体力学(CFD)モデリングを改良するための貴重なセグメンテーションデータを提供するだけでなく、原子力工学と水力工学の両分野における重要な進歩への道を開くものである。
-
transitionsYang, Q.*; Yang, X.*; Wang, Y.*; Fei, Y.*; Li, F.*; Zheng, H.*; Li, K.*; Han, Y.*; 服部 高典; Zhu, P.*; et al.
Nature Communications (Internet), 15, p.7778_1 - 7778_9, 2024/09
被引用回数：11 パーセンタイル：88.19(Multidisciplinary Sciences)明るい一重項励起子と三重項励起子を同時に発現する発光材料は、オプトエレクトロニクス、サイネージ、情報暗号化において大きな可能性を秘めている。しかしながら、高性能の白色発光を実現するためには、蛍光と燐光の寄与が不均衡であることが大きな障害となっている。ここでは、水素結合の協同効果による圧力処理エンジニアリングによって、n--遷移の混合を実現し、イソフタル酸(IPA)中で三重項状態の発光を7%から40%に高めることで、この課題に対処した。加圧処理したIPAでは、蛍光と燐光のハイブリッドに基づく優れた白色発光が得られ、フォトルミネッセンス量子収率は当初の19%(青色発光)から75%に増加した。その場での高圧IRスペクトル、X線回折、中性子回折から、圧力の上昇に伴い水素結合が連続的に強化されることが明らかになった。さらに、この強化された水素結合は、圧力処理後も常圧条件下まで保持され、バランスの取れた一重項/三重項励起子集団のための効率的な系間交差を目的としたIPAに与え、効率的な白色発光をもたらした。この研究は、有機低分子の三重項状態を明るくするルートを提案するだけでなく、一重項励起子と三重項励起子の比率を調節して、高性能の白色発光を構築するものである。
Hu, F. F.*; Qin, T. Y.*; Ao, N.*; Su, Y. H.; Zhou, L.*; 徐 平光; Parker, J. D.*; 篠原 武尚; Chen, J.*; Wu, S. C.*
Engineering Fracture Mechanics, 306, p.110267_1 - 110267_18, 2024/08
被引用回数：2 パーセンタイル：55.14(Mechanics)Non-destructive and quantitative mapping of gradient residual strain distribution in surface-hardened railway S38C axles could provide a positive reference for determining service lifetime and maintenance strategy. To tackle this concern, time-of-flight neutron Bragg-edge transmission imaging was employed by real axle samples with and without impacted crater. A novel and simple procedure to formulate the residual strain field was also developed in this work, with the transmission batch code in Appendix A. By mapping the global two- dimensional residual strains, it can be verified that the residual strains into the axle are uniformly distributed in the hoop direction. Subsequently, it was revealed that the axial and hoop residual strains, respectively in the cylinder and the long strip samples prepared from a real S38C hollow axle, indicated a gradient evolution distribution with a depth of 
8 mm, covering a range of -5500 1000 
for axial strains and -6500 1000 for hoop strains. More importantly, the maximum compressive lattice strain of the cylinder sample was increased by 15.61%, and 22.35% at the impacting speeds of 100, and 125 m/s, respectively; and that of the long strip sample increased by 29.17%, and 43.70%, respectively. It can thus be concluded that lattice strains have redistributed around the impact crater, demonstrating the local alteration of the residual strain field. These new findings suggest the localized variation in residual strains should be taken into account while evaluating the service damage evolution of railway axles, especially those affected by high-speed impacts during operation.
Qin, T. Y.*; Hu, F. F.*; 徐 平光; Zhang, H.*; Zhou, L.*; Ao, N.*; Su, Y. H.; 菖蒲 敬久; Wu, S. C.*
International Journal of Fatigue, 185, p.108336_1 - 108336_13, 2024/08
被引用回数：9 パーセンタイル：93.27(Engineering, Mechanical)Gradient distribution of triaxial residual stresses to a depth of several millimeters is retained in middle carbon steel S38C axles after high-frequency induction hardening, which has become a critical concern for fatigue structural integrity. To address this, the axial, hoop, and radial gradient residual strains inside the axles were measured for the first time by advanced neutron diffraction. The SIGINI Fortran subroutine was then adopted to reconstruct the global initial residual stress field from the measured data. Experimental and simulation results show that residual stresses of about -520 MPa (axial), -710 MPa (hoop), and -40 MPa (radial) residual stress were retained below the axle surface. Subsequently, the fatigue crack propagation behavior of S38C axles was numerically investigated in the framework of fracture mechanics. The calculated results clearly show that the compressive residual stresses at a depth of 0?3 mm from the axle surface lead to a low crack growth driving force, and that fatigue cracks do not propagate as long as the crack depth is less than 3.7 mm for hollow S38C axles. These results further indicate that the maximum defect size allowed in routine inspections is acceptable from a safety and economic point of view. Accurate measurement and characterization of the global gradient residual stress field through experiments and simulations can provide an important reference for optimizing the mileage intervals of nondestructive testing (NDT) of surface defects in these surface-strengthened railway axles.
Zhou, L.*; Zhang, H.*; Qin, T. Y.*; Hu, F. F.*; 徐 平光; Ao, N.*; Su, Y. H.; He, L. H.*; Li, X. H.*; Zhang, J. R.*; et al.
Metallurgical and Materials Transactions A, 55(7), p.2175 - 2185, 2024/07
被引用回数：3 パーセンタイル：70.74(Materials Science, Multidisciplinary)High-speed railway S38C axles undergo surface induction hardening for durability, but are susceptible to fatigue cracks from foreign object impact. The neutron diffraction method was employed to measure the residual strain in S38C axles, obtaining microscopic lattice distortion data, for the gradient layer at a depth of 8 mm under the surface. The results showed that after induction-hardening, the microscopic lattice distortion had a gradient distribution, decreasing with the distance from the surface. However, in the case of impacting speed of 600 km/m, the average microscopic lattice distortion increased with the distance from the surface, reaching a maximum augmentation of 55 pct. These findings indicate a strong experimental basis, and improve our understanding of the relationship between macroscopic residual stress and decision-making, in regard to operation and maintenance.
Zeng, Z.*; Zhou, C.*; Zhou, H.*; Han, L.*; Chi, R.*; Li, K.*; 古府 麻衣子; 中島 健次; Wei, Y.*; Zhang, W.*; et al.
Nature Physics, 20(7), p.1097 - 1102, 2024/07
被引用回数：12 パーセンタイル：94.31(Physics, Multidisciplinary)Emergent quasiparticles with a Dirac dispersion in condensed matter systems can be described by the Dirac equation for relativistic electrons, in analogy with Dirac particles in high-energy physics. For example, electrons with a Dirac dispersion have been intensively studied in electronic systems such as graphene and topological insulators. However, charge is not a prerequisite for Dirac fermions, and the emergence of Dirac fermions without a charge degree of freedom has been theoretically predicted to be realized in Dirac quantum spin liquids. These quasiparticles carry a spin of 1/2 but are charge-neutral and so are called spinons. Here we show that the spin excitations of a kagome antiferromagnet, YCu
(OD)
Br
[Br
(OD)
], are conical with a spin continuum inside, which is consistent with the convolution of two Dirac spinons. The predictions of a Dirac spin liquid model with a spinon velocity obtained from spectral measurements are in agreement with the low-temperature specific heat of the sample. Our results, thus, provide spectral evidence for a Dirac quantum spin liquid state emerging in this kagome lattice antiferromagnet. However, the locations of the conical spin excitations differ from those calculated by the nearest-neighbor Heisenberg model, suggesting the Dirac spinons have an unexpected origin.
- and 
-processes following 
-process in the collapsar jetHe, Z.*; 梶野 敏貴*; 日下部 元彦*; Zhou, S.-G.*; 小浦 寛之; 千葉 敏*; Li, H.*; Lin, Y.*
Astrophysical Journal Letters, 966(2), p.L37_1 - L37_7, 2024/05
被引用回数：1 パーセンタイル：31.74(Astronomy & Astrophysics)The slow and intermediate neutron-capture processes, - and -processes, are believed to occur in asymptotic giant branch stars to provide half of the heavy atomic nuclei with A 
. We suggest a possibility that certain types of outflows found in the collapsar, which is a supernova generated by a rapidly rotating massive star undergoing core collapse, leaving behind a black hole and emitting relativistic jets, can provide conditions that are viable for - and -processes as secondary processes following the rapid neutron-capture process, -process. We propose that the pronounced odd-even effect in the mass abundance pattern near rare earth elements in metal-deficient halo stars could be an observational hint for the - and -processes in the collapsar.
Zhou, X.*; 福谷 克之; 他9名*
Applied Physics Letters, 124(8), p.082103_1 - 082103_7, 2024/02
被引用回数：6 パーセンタイル：87.23(Physics, Applied)Electron-doping Mottronics within correlated vanadium dioxide opens up a paradigm to abruptly regulate the Mottronic phase transitions via adjusting the 
-orbital occupancy and configuration. Nevertheless, the potential impact of high-valence elementary substitution in the hydrogen-associated Mottronic transitions of VO
is yet unclear. Herein, we demonstrate the role of high-valence elementary substitution in regulating the hydrogen-triggered Mottronic transitions of VO, assisted by quantitative hydrogen analysis using the nuclear reaction analysis. Substituting vanadium with a high-valence transitional metal within doped-VO largely reduces the hydrogen incorporation compared to the intrinsic VO under the low temperature hydrogenation process. Therefore, in contrast to hydrogen-induced electron localization of intrinsic VO upon low-temperature hydrogenation, only the hydrogen-triggered metallic state is observed within the hydrogen-associated phase diagram of W
V
O, as further probed by the near-edge X-ray absorption fine structure analysis and X-ray photoelectron spectroscopy. The present work reveals the overlooked role associated with the donor substitutions that largely influences the competitive equilibrium between the two rival hydrogen-induced Mottronic transitions within VO toward either the metallic or the highly insulating phase.
R
hm, W.*; 伴 信彦*; Chen, J.*; Li, C.*; Dobynde, M.*; Durante, M.*; El-Jaby, S.*; 込山 立人*; 小笹 晃太郎*; 佐藤 達彦; et al.
Journal of Medical Physics - Zeitschrift fr medizinische Physik -, 34(1), p.4 - 13, 2024/02
国際放射線防護委員会(ICRP)は、過去90年間に渡って世界各国や国際的な放射線防護の枠組み作りに貢献してきた。2019年、ICRPは宇宙飛行士の放射線防護に関わる様々な問題に対応したタスクグループ(TG115)を立ち上げ、地上の放射線防護体系と宇宙の放射線防護体系との共通の枠組み作りに取り組んでいる。本論文では、現時点でICRPが定めている宇宙放射線防護体系についてとりまとめて報告する。
neutron diffractionZhou, Y.*; Song, W.*; Zhang, F.*; Wu, Y.*; Lei, Z.*; Jiao, M.*; Zhang, X.*; Dong, J.*; Zhang, Y.*; Yang, M.*; et al.
Journal of Alloys and Compounds, 971, p.172635_1 - 172635_7, 2024/01
被引用回数：3 パーセンタイル：23.52(Chemistry, Physical)The grain orientation-dependent lattice strain evolution of a (TiZrHfNb)
refractory high-entropy alloy (HEA) during tensile loading has been investigated using neutron diffraction. The equivalent strain-hardening rate of each of the primary 
-oriented grain families was found to be relatively low, manifesting the macroscopically weak work-hardening ability of such a body-centered cubic (BCC)-structured HEA. This finding is indicative of a dislocation planar slip mode that is confined in a few single-slip planes and leads to in-plane softening by high pile-up stresses.
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：11 パーセンタイル：85.96(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.
FeSi角田 一樹; 藤田 裕一*; Zhou, W.*; 増田 啓介*; 川崎 郁斗; 藤森 伸一; 木村 昭夫*; 桜庭 裕弥*
Physical Review B, 108(24), p.L241101_1 - L241101_6, 2023/12
被引用回数：2 パーセンタイル：33.96(Materials Science, Multidisciplinary)We investigated the element-specific electronic structure of a half-metallic Weyl ferromagnet candidate CoFeSi film by utilizing soft-X-ray resonant photoelectron spectroscopy and first-principles calculations with/without considering on-site Coulomb interaction. Fe 2
-3 resonant photoelectron experiment revealed that the Fe 3 states exist around 2 and 4 eV below the Fermi energy. Our calculations, based on the generalized gradient approximation without considering Coulomb interaction at the Fe site, successfully reproduced the experimentally observed Fe 3 partial density of states. Our findings shed light on the highly controversial correlation effect of CoFeSi, offering valuable insights into its half-metallicity and Weyl semi-metallicity.
Yang, D. S.*; Wu, Y.*; Kanatzidis, E. E.*; Avila, R.*; Zhou, M.*; Bai, Y.*; Chen, S.*; 関根 由莉奈; Kim, J.*; Deng, Y.*; et al.
Materials Horizons, 10(11), p.4992 - 5003, 2023/09
被引用回数：12 パーセンタイル：78.05(Chemistry, Multidisciplinary)本論文では、ハード及びソフトハイブリッド材料システムでの3Dプリントによって形成されたマイクロ流体ネットワーク、統合バルブ、およびマイクロスケール光学キュベットにより、汗成分に対してその場で分光および蛍光分析した成果を紹介する。一連の試験により、これらのマイクロキュベットシステムが汗中の銅、塩化物、グルコースの濃度と汗のpHを実験室レベルの精度と感度で評価できることが実証された。
Fe
intermetallic compoundCao, Y.*; Zhou, H.*; Khmelevskyi, S.*; Lin, K.*; Avdeev, M.*; Wang, C.-W.*; Wang, B.*; Hu, F.*; 加藤 健一*; 服部 高典; et al.
Chemistry of Materials, 35(8), p.3249 - 3255, 2023/04
被引用回数：4 パーセンタイル：20.33(Chemistry, Physical)静水圧や化学圧力は、結晶構造を変化させる効率的な刺激であり、材料科学において電気的、磁気的特性のチューニングによく利用されている。しかし、化学圧力は定量化が困難であり、これら両者の定量的な対応関係はまだよくわかっていない。本研究では、負の熱膨張(NTE)を持つ永久磁石の候補である金属間化合物を調べた。放射光X線その場観察により、AlをドープしたHoFeに負の化学圧力があることを明らかにし、単位セル体積の温度・圧力依存性を用いそれを定量的に評価した。また、磁化測定と中性子回折測定を組み合わせることで、磁気秩序に対する化学圧力と静水圧の違いを比較した。興味深いことに、圧力はNTEの抑制と増強を制御するために使用することができた。電子状態計算から、圧力がFermiレベル(EF)に対する主要バンドの上部に影響を与えたことを示しており、これは磁気安定性に影響を与え、それが磁気とNTEを調節する上で重要な役割を果たしていることがわかった。本研究は、圧力の影響を理解し、それを利用して機能性材料の特性を制御する良い例を示している。
Zhou, Z.*; Frost, W.*; Lloyd, D. C.*; 関 剛斎*; 窪田 崇秀*; Ramos, R.*; 齊藤 英治; 高梨 弘毅; 廣畑 貴文*
Journal of Magnetism and Magnetic Materials, 571, p.170575_1 - 170575_5, 2023/04
被引用回数：1 パーセンタイル：10.32(Materials Science, Multidisciplinary)Recent development in neuromorphic computation allows us to achieve low power and highly efficient calculations better than the conventional von Neumann computation. In order to achieve realistic synaptic operation, potentiation to add weighting to strengthen a selected artificial synapse. Such functionality can be achieved by reducing the electrical resistance of the artificial synapse. Recently, a ferromagnetic Heusler alloy used in a magnetoresistive junction has been demonstrated to crystallise via the layer-by-layer mode by introducing an electrical current pulse. In this study, we have extended the current-induced crystallisation to a junction with epitaxially-grown Heusler alloy after post-annealing for crystallisation. By combining this potentiation functionality with the neuromorphic operation, realistic synaptic computation can be developed.
Zhang, H.*; Wu, S. C.*; Ao, N.*; Zhang, J. W.*; Li, H.*; Zhou, L.*; 徐 平光; Su, Y. H.
International Journal of Fatigue, 166, p.107296_1 - 107296_11, 2023/01
被引用回数：19 パーセンタイル：84.17(Engineering, Mechanical)Abnormal damages in railway axles can lead to a significant hazard to running safety and reliability. To this end, a surface treatment was selected to effectively inhibit fatigue crack initiation and growth. In this study, a single edge notch bending fatigue test campaign with artificial notches was conducted to elucidate the fatigue crack non-propagation behavior in railway S38C axles subjected to an induction hardening process. The fatigue cracking behavior in the gradient structure was revealed by optical microscopy, electron backscatter diffraction, and fractography. The microhardness distribution was measured using a Vickers tester. The obtained results show that the microhardness of the strengthening layer is nearly triple that of the matrix. Owing to the gradient microstructures and hardness, as well as compressive residual stress, the fatigue long crack propagates faster once it passes through the hardened zone (approximately 2.0 mm in the radial depth). Thereafter, local retarding (including deflection, branching, and blunting) of the long crack occurs because of the relatively coarse ferrite and pearlite in the transition region and matrix. Totally, this fatigue cracking resistance is reasonably believed to be due to the gradient microstructure and residual stress. These findings help to tailor a suitable detection strategy for maximum defects or cracks in railway axles.
Miao, Z.-Q.*; Xia, C.-J.*; Lai, X.-Y.*; 丸山 敏毅; Xu, R.-X.*; Zhou, E.-P.*
International Journal of Modern Physics E, 31(4), p.2250037_1 - 2250037_20, 2022/04
被引用回数：11 パーセンタイル：84.55(Physics, Nuclear)It is suggested that pulsar-like compact stars are comprised entirely of strangeons (quark-clusters with three-light-flavor symmetry) and a small amount of electrons. To constrain the properties of strangeon stars, we propose a linked bag model to describe matter with the strong interaction in both 2-flavored (nucleons) and 3-flavored (hyperons, strangeons, etc.) scenarios. The parameters are calibrated to reproduce the saturation properties of nuclear matter. The energy per baryon of strangeon matter is smaller than that of baryon matter if the strangeon carries a large number of valence quarks, which stiffens the equation of state and consequently increases the maximum mass of strangeon stars. The maximum mass and tidal deformability of strangeon stars within the present model are consistent with the observation, i.e. the maximum mass of strangeon stars can be 2.5 solar mass, and the tidal deformability of a 1.4 solar mass star can be 
.
Zhang, W. Q.*; 山口 敏男*; Fang, C. H.*; 吉田 亨次*; Zhou, Y. Q.*; Zhu, F. Y.*; 町田 真一*; 服部 高典; Li, W.*
Journal of Molecular Liquids, 348, p.118080_1 - 118080_11, 2022/02
被引用回数：3 パーセンタイル：24.49(Chemistry, Physical)3mol/kgのRbCl水溶液におけるイオンの水和・会合と水素結合した水の構造を、298K/0.1MPa, 298K/1GPa, 523K/1GPa, 523K/4GPaにおける中性子回折と経験的ポテンシャル構造精密化モデリングにより調べた。その結果、構造パラメータは温度と圧力に依存していることがわかった。高圧・高温条件では、Rb
とCl
の第二水和層がより明確になる。第一水和層におけるRbの平均酸素配位数は、配位距離を0.290nmから0.288nmに縮めながら、常圧では6.3だったのが、4GPaでは8.9に増加した。第一水和シェルのClの平均酸素配位数は、常圧で5.9、4GPaで9.1と圧力により増加し、対応する配位距離は0.322nmから0.314nmへと減少した。Rbと中心の水分子の第一溶媒和シェルにおける水双極子の配向は圧力に敏感であるが、Clの第一溶媒和シェルにおける水双極子の配向は温度圧力によらずあまり変化しなかった。Rb-Clの隣接イオンペアの数は、温度が高くなると減少し、圧力が高くなると増加する。水分子は密に詰まっており、極限状態では水分子の四面体水素結合ネットワークはもはや存在しない。
