検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 120 件中 1件目~20件目を表示

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

Nanocellulose hydrogels formed via crystalline transformation from cellulose I to II and subsequent freeze cross-linking reaction

関根 由莉奈; 南川 卓也; 廣井 孝介; 大場 洋次郎*; 永川 栄泰*; 杉田 剛; 柴山 由樹; 深澤 倫子*

Carbohydrate Polymers, 327, p.121538_1 - 121538_11, 2024/03

セルロースの結晶転移とその後の凍結架橋反応によってナノセルロース(NC)から形成された、無毒で強靱なNCゲルを開発した。低濃度のNaOHの使用と凍結を併用すると、凍結濃縮によりセルロースIからIIへのNCの結晶相転移が誘導されることを見出した。結晶相転移後、凍結濃縮層(FCL)内のNCとCA間の架橋により、強力なNCネットワーク構造が形成され、高い機械的強度を備えたNCハイドロゲルが形成した。凍結架橋したNCハイドロゲルは、NC-NaOHゾルと粉末吸着剤を混合することにより吸着剤を内部空間に容易に保持し、高い重金属除去効率を示した。この結果は、機能性材料の開発における化学修飾されていないセルロースの多用途性を示し、実用化の可能性を示すものである。

論文

Upgrade of the small-angle neutron scattering diffractometer SANS-J at JRR-3

熊田 高之; 元川 竜平; 大場 洋次郎; 中川 洋; 関根 由莉奈; Micheau, C.; 上田 祐生; 杉田 剛; 美留町 厚; 佐々木 未来; et al.

Journal of Applied Crystallography, 56(6), p.1776 - 1783, 2023/12

既存のメイン検出器および高位置分解能フォトマル検出器に加えて新規に導入した前面検出器を組み合わせることにより、波数0.002nm$$^{-1}$$から6nm$$^{-1}$$にわたる散乱を3つの光学機器配置により切れ目なく測定できるようになった。またグラフィカルユーザーインターフェースの導入と併せて装置のユーザビリティが大幅に向上した。

論文

Development of a D$$_2$$O/H$$_2$$O vapor generator for contrast-variation neutron scattering

有馬 寛*; 高田 慎一; 笠井 聡*; 大内 啓一*; 森川 利明*; 宮田 登*; 宮崎 司*; 青木 裕之; 岩瀬 裕希*; 廣井 孝介; et al.

Journal of Applied Crystallography, 56(6), p.1802 - 1812, 2023/12

The contrast-variation technique in neutron scattering experiments plays a pivotal role in distinguishing partial structures within multi-component complexes, facilitating the elucidation of distinct sample constituents. This differentiation is achieved using different isotopes, namely hydrogen and deuterium, which possess varying neutron scattering characteristics. This study presents a novel vapor generator designed for neutron scattering experiments, enabling continuous control of the D$$_2$$O/H$$_2$$O ratio of the vapor. This feature is especially useful for contrast-variation studies. The generator features two saturators and four mass flow controllers, allowing for the rapid and independent generation of D$$_2$$O/H$$_2$$O vapors. Additionally, the incorporation of the two-temperature method ensures accurate dew point control within a margin of $$pm$$0.2$$^{circ}$$Cdp. This setup proves useful for conducting time-resolved experiments and can accelerate research on functional polymers, such as polymer electrolyte membranes for fuel cells, where water potential assumes critical importance.

論文

Polarized neutrons observed nanometer-thick crystalline ice plates in frozen glucose solution

熊田 高之; 中川 洋; 三浦 大輔; 関根 由莉奈; 元川 竜平; 廣井 孝介; 稲村 泰弘; 奥 隆之; 大石 一城*; 森川 利明*; et al.

Journal of Physical Chemistry Letters (Internet), 14(34), p.7638 - 7643, 2023/08

スピンコントラスト変調中性子小角散乱法を用いて急冷したグルコース濃厚溶液中に生成するナノアイス結晶の構造解析を行ったところ、厚さ1nm程度、半径数十nm以上の平面上の氷晶が生成していることを見出した。本結果はグルコース分子が特定の成長面に吸着することによりその面からの結晶成長を阻害していることを示す。

論文

Dynamic exchange of amphiphilic random copolymers between micelles in water; Kinetics and mechanism analyzed by TR-SANS

Hibino, Masayuki*; 高田 慎一; 廣井 孝介; 青木 裕之; 寺島 崇矢*

Macromolecules, 56(8), p.2955 - 2964, 2023/04

Amphiphilic random copolymers bearing poly(ethylene glycol) (PEG) and alkyl groups as side chains are intermolecularly self-assembled into size-controlled multichain micelles in water. The random copolymer micelles are known to induce the exchange of their polymer chains, whereas the details of the kinetics and mechanism have not been elucidated yet. Herein, we investigated the exchange kinetics and mechanism of the random copolymer chains between their micelles by time-resolved small-angle neutron scattering (TR-SANS). For this purpose, random copolymers carrying PEG and deuterated butyl or dodecyl groups were designed for deuterated micelles. After mixing deuterated and non-deuterated micelle solutions, the resulting mixtures were monitored by TR-SANS at various concentrations and temperatures. The scattering intensity of the micelle mixtures decayed with time, indicating that deuterated copolymers were gradually mixed with non-deuterated copolymers via chain exchange between their micelles to form micelles consisting of both deuterated and non-deuterated copolymers. The kinetic analysis revealed that the exchange of their polymer chains involved two mechanisms: A unimer release and insertion pathway was dominant in diluted conditions, whereas the contribution of a micelle collision pathway increased with increasing total polymer concentration and temperature. The activation energy of the polymer exchange process was dependent on the hydrophobic alkyl groups and larger than that of a related surfactant micelle.

論文

Polarized neutron scattering study of hollow Fe$$_{3}$$O$$_{4}$$ submicron spherical particles

小林 悟*; 野村 英志*; 千葉 桃子*; 河村 幸彦*; 大石 一城*; 廣井 孝介; 鈴木 淳市*

Journal of Magnetism and Magnetic Materials, 569, p.170410_1 - 170410_9, 2023/03

We report results of polarized small-angle and wide-angle neutron scattering experiments at $$T$$ = 10 and 300 K for 420 nm-sized hollow Fe$$_{3}$$O$$_{4}$$ spherical particles. Each hollow particle is a mesocrystal, which is composed of small nanoparticles with nearly the same crystallographic orientation. Polarized neutron experiments allow us to evaluate magnetic correlations of parallel and perpendicular magnetization components with respect to magnetic field during magnetization process. Small-angle neutron scattering reveals that as the magnetic field decreases from a saturation field of 10 kOe, the perpendicular magnetization component maximizes around zero applied field, whereas the parallel component minimizes. This behavior was observed below and above Verwey transition temperature of $$sim$$ 120 K. Calculations of neutron intensities for vortex structures suggest the reorientation of the vortex core towards the magnetocrystalline anisotropy axis from the magnetic field direction at low applied fields. Moreover, a magnetic domain length obtained from the wide-angle scattering is of the order of 30-40 nm and comparable to the size of the small nanoparticles forming a hollow sphere, suggesting that magnetic correlations within the small nanoparticles always retain during magnetization process.

論文

Sodium diffusion in hard carbon studied by small- and wide-angle neutron scattering and muon spin relaxation

大石 一城*; 五十嵐 大輔*; 多々良 涼一*; 河村 幸彦*; 廣井 孝介; 鈴木 淳市*; 梅垣 いづみ*; 西村 昇一郎*; 幸田 章宏*; 駒場 慎一*; et al.

Journal of Physics; Conference Series, 2462, p.012048_1 - 012048_5, 2023/03

Hard carbon is the most common anode material for Na-ion battery. The structure of the hard carbon and the dynamics of Na-ion in hard carbon were studied with small- and wide- angle neutron scattering and muon spin relaxation technique. The neutron scattering revealed the increase of interlayer distance between graphenes and decrease of the size of nanopores with increasing sodium intercalation in hard carbon. The muon spin relaxation revealed that a systematic increase in the field fluctuation rate with increasing temperature evidenced a thermally activated sodium diffusion. Assuming the two-dimensional diffusion of Na-ion in the graphene layers, the self-diffusion coefficient of Na-ion was estimated to be 2.6$$times$$10$$^{-11}$$ cm$$^{2}$$/s at 310 K, with a thermal activation energy of 39(7) meV.

論文

Magnetic structural analysis of nanocrystalline soft magnets by small-angle neutron scattering

間宮 広明*; 大場 洋次郎; 廣井 孝介; 宮武 孝之*; Gautam, R.*; Sepehri-Amin, H.*; 大久保 忠勝*

IEEE Magnetics Letters, 14, p.7100105_1 - 7100105_5, 2023/02

 被引用回数:0 パーセンタイル:64.19(Engineering, Electrical & Electronic)

In nanocrystalline soft magnets, microscopic magnetic states inside the materials important for macroscopic soft magnetic properties. Therefore, we measured small-angle neutron scattering of the nanocrystalline soft magnets. The results clearly indicate the magnetic scattering of the nano-crystallized samples, while the as-quenched sample shows only featureless scattering. This provides essential information for the relationship between the magnetic nanostructures and the macroscopic magnetic softness.

論文

Microscopic structural changes during the freeze cross-linking reaction in carboxymethyl cellulose nanofiber hydrogels

三浦 大輔*; 関根 由莉奈; 南川 卓也; 杉田 剛; 大場 洋次郎; 廣井 孝介; 大澤 辰彦

Carbohydrate Polymer Technologies and Applications (Internet), 4, p.100251_1 - 100251_9, 2022/12

凍結架橋により形成されたカルボキシメチルセルロースナノファイバー(CMCF)ゲルの反応機構を調べた。異なる反応時間で調製されたCMCFヒドロゲルの物性評価により、凍結架橋反応中の階層構造変化の観察に成功した。凍結架橋CMCFヒドロゲルは、従来の方法で形成された通常のゲルとは異なり、オングストロームからマイクロメートルスケールまでの特徴的な階層構造を示し、その特異的構造が飛躍的な力学強度の向上に寄与していることを明らかにした。

論文

Magnetization process of cubic Fe$$_3$$O$$_4$$ submicron particles studied by polarized small-angle neutron scattering

野村 英志*; 千葉 桃子*; 松尾 咲琴*; 野田 千晶*; 小林 悟*; Manjanna, J.*; 河村 幸彦*; 大石 一城*; 廣井 孝介; 鈴木 淳市*

AIP Advances (Internet), 12(3), p.035034_1 - 035034_5, 2022/03

We report results of polarized small-angle neutron scattering (SANS) experiments at T = 10 K and 300 K for cubic Fe$$_3$$O$$_4$$ submicron- sized particles, where formation of a complex spin vortex is expected. Magnetic SANS intensities of magnetization components in the direction perpendicular and parallel to the magnetic field were observed to change significantly at around the coercivity. Magnetization components parallel to the field minimizes around the coercivity both at T = 10 K and 300 K, whereas those perpendicular to the magnetic field maximizes near the coercivity and the maximum value differ greatly, depending on the temperature. Based on results of micromagnetic simulations, the observed SANS intensities were interpreted as due to magnetic structural changes from a flower to a spin vortex state and gradual tilting of a vortex core from the external field to magnetocrystalline anisotropy axes at low fields.

論文

Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms

三浦 大輔*; 熊田 高之; 関根 由莉奈; 奥 隆之; 高田 慎一; 廣井 孝介; 岩田 高広*

J-PARC 22-02; J-PARC MLF Annual Report 2021, p.6 - 7, 2022/03

スピンコントラスト変調中性子粉末結晶構造解析法を用いてグルタミン酸結晶を測定したところ、水素核偏極度に応じて偏極中性子の回折ピーク強度がピークごとに大きく変化した。その変化を解析することにより水素原子間同士の相関関数および水素原子と他の原子との相関関数を抽出することに成功した。

論文

Strain distribution visualization of punched electrical steel sheets using neutron Bragg-edge transmission imaging

笹田 星児*; Takahashi, Yoshihito*; Takeuchi, Keisuke*; 廣井 孝介; Su, Y. H.; 篠原 武尚; 渡辺 賢一*; 瓜谷 章*

Japanese Journal of Applied Physics, 61(4), p.046004_1 - 046004_8, 2022/03

Residual strains in a punched electrical steel sheet increase the iron loss in the steel sheet. To accurately estimate the effect of residual strain on iron loss, the residual strain distribution in a punched electrical steel sheet should be evaluated. In this study, we demonstrated the two- dimensional imaging of the residual strain distribution in a punched electrical steel sheet using the neutron Bragg-edge transmission imaging method. To improve the accuracy of strain measurement with minimal deterioration of spatial resolution, we applied a process of superposing many specimen images. The tensile strain near the punched edge and the compressive strain inside the core were experimentally confirmed using this method. Finally, the neutron Bragg-edge imaging results and those obtained from kernel average misorientation map using electron backscattered diffraction were compared to verify the validity of the proposed method.

論文

Spontaneous formations of nanoconfined water in ionic liquids by small-angle neutron scattering

阿部 洋*; 根本 文也*; 廣井 孝介; 大石 一城*; 高田 慎一

Journal of Molecular Liquids, 346, p.117035_1 - 117035_6, 2022/01

In this study, monodispersive nanoconfined water ("water pocket") is organized spontaneously in hydrophilic ionic liquid (IL). The IL is 1-alkyl-3-methylimidazolium nitrate ([C$$_{n}$$mim][NO$$_{3}$$] $$n$$ = 2, 6, and 8). By small-angle neutron scattering (SANS), D$$_{2}$$O aggregations in the IL are detected. There are no SANS peaks for [C$$_{2}$$mim][NO$$_{3}$$]-D$$_{2}$$O, but, in [C$$_{6}$$mim][NO$$_{3}$$]-$$x$$ mol% D$$_{2}$$O, a SANS peak can be observed at $$70 < x < 90$$ mol%. The peak intensity, position, and profile change according to water concentration and temperature. Pure [C$$_{8}$$mim][NO$$_{3}$$] has a distinct SANS peak, reflecting on the nanodomains at room temperature. Above 70 mol%, the SANS peak of [C$$_{8}$$mim][NO$$_{3}$$]-D$$_{2}$$O sharply increases and shifts to the low-Q position. The water pocket develops proportionate to water concentration, and its morphologies are visualized using an ${it ab initio}$ bead model. The alkyl chain length dependence of the water pocket is clarified by a three-dimensional reconstruction method.

論文

High-spatial-resolution measurement of magnetization distribution using polarized neutron imaging

笹田 星児*; 廣井 孝介; 小山内 健太*; 篠原 武尚; Watanabe, K.*; 瓜谷 章*

Japanese Journal of Applied Physics, 60(12), p.126003_1 - 126003_6, 2021/12

 被引用回数:0 パーセンタイル:8.23(Physics, Applied)

The evaluation of the magnetization distribution inside a bulk magnet is important for ensuring the performance of automotive motors because it strongly depends on the quality of magnetization inside the permanent magnet. In the conventional destructive method, it is difficult to accurately measure the magnetization with a high spatial resolution. The polarized neutron imaging technique can be used to visualize the distribution of the magnetic flux density inside a magnet nondestructively. In this study, we demonstrated the imaging of the magnetization distribution using polarized neutrons in an anisotropic ferrite magnet sample. The 2D distribution of the magnetization was experimentally obtained by polarized neutron imaging with a high spatial resolution of less than 1 mm. Furthermore, the validity of the results was confirmed by comparing them with those obtained using the conventional destructive method.

論文

Polarization analysis for small-angle neutron scattering with a $$^{3}$$He spin filter at a pulsed neutron source

奥平 琢也; 上田 祐生; 廣井 孝介; 元川 竜平; 稲村 泰弘; 高田 慎一; 奥 隆之; 鈴木 淳市*; 高橋 慎吾*; 遠藤 仁*; et al.

Journal of Applied Crystallography, 54(2), p.548 - 556, 2021/04

 被引用回数:1 パーセンタイル:34.11(Chemistry, Multidisciplinary)

$$^{3}$$Heスピンフィルタを中性子スピン解析子として使用することにより、パルス中性子源での中性子小角散乱実験において、偏極解析を行うことに成功した。本実験に使用した$$^{3}$$Heスピンフィルタは中性子小角散乱実験を行うために十分な立体角をカバーすることができ、$$^{3}$$He偏極緩和時間も数日と長く、これは実験を完遂するために十分な性能である。水素原子による非干渉性散乱は非常に大きく、試料の組成から計算によって非干渉性散乱量を見積もる試みが行われていたが、正確に非干渉性散乱量を決定することは難しかった。しかし本研究では試料内での中性子の多重散乱を考慮した偏極解析実験を行うことで、干渉性散乱と非干渉性散乱を正確に分離することが可能となった。現在までパルス中性子源での中性子小角散乱では、偏極解析の手法が確立されていなかったが、本成果によって、様々な種類の試料に対して干渉性散乱と非干渉性散乱を正確に分離することができるようになると予想される。

論文

Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms

三浦 大輔*; 熊田 高之; 関根 由莉奈; 元川 竜平; 中川 洋; 大場 洋次郎; 大原 高志; 高田 慎一; 廣井 孝介; 森川 利明*; et al.

Journal of Applied Crystallography, 54(2), p.454 - 460, 2021/04

AA2020-0724.pdf:2.05MB

 被引用回数:1 パーセンタイル:18.34(Chemistry, Multidisciplinary)

山形大学が原子核物理実験用に開発した結晶試料の核スピン偏極技術を、スピンコントラスト偏極中性子回折測定法に展開し、水素核偏極化されたグルタミン酸を用いて粉末結晶試料中の水素の配向および凝集・分散などの構造情報を抽出できることを実証した。

論文

Study of neutron-nuclear spin correlation term with a polarized Xe target

酒井 健二; 奥 隆之; 奥平 琢也; 甲斐 哲也; 原田 正英; 廣井 孝介; 林田 洋寿*; 加倉井 和久*; 清水 裕彦*; 広田 克也*; et al.

JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03

中性子基礎物理学において、パリティ非保存(PNC)項や時間反転非保存項と干渉する中性子スピン$${bf s}$$と標的核スピン$${bf I}$$の相関項$${bf s}cdot{bf I}$$は重要な研究テーマである。中性子共鳴ピーク付近でPNC項の増大が測定され、スピン交換光ポンピング(SEOP)法により$$sim 10^{-1}$$の偏極が得られるキセノン(Xe)は、本研究にとって興味深い原子核である。我々は小型SEOPシステムを用いた偏極Xe標的を開発し、核破砕中性子源で得られる大強度の熱外中性子ビームを利用した$${bf s}cdot{bf I}$$項の研究を計画している。その第一段階として、我々は$$^{129}$$Xeの9.6eV共鳴ピーク付近でのXe偏極時と非偏極時の中性子透過率比の変化$$Delta R$$を捕らえることで、$${bf s}cdot{bf I}$$項に起因する中性子偏極能力の測定をJ-PARC物質・生命科学実験施設(MLF)のBL10で試みた。実験では、本測定系がドップラーブロードニングの影響($$Delta R_{rm DB} , {approx},10^{-2}$$)を検知できることを実証した上で、初期結果として有意な$$Delta R$$の値を得ている。現在は$$Delta R$$をより詳細に評価するために、核磁気・電子スピン共鳴法によるXe偏極度の導出を進めている。

論文

Structural investigation of sulfonated polyphenylene ionomers for the design of better performing proton-conductive membranes

椎野 佳祐*; 大友 季哉; 山田 武*; 有馬 寛*; 廣井 孝介; 高田 慎一; 三宅 純平*; 宮武 健治*

ACS Applied Polymer Materials (Internet), 2(12), p.5558 - 5565, 2020/11

To achieve high-performance proton-exchange membranes (PEMs), understanding of the polymer structure/ property relationship is crucial. In particular, the structure of water clusters (number, size, interdomain distance, interconnectivity, etc.) and hydrophobic domains dominates important membrane properties, such as proton conductivity and mechanical strength, which can be adjusted by the monomer sequence in the polymer chains. In the present paper, we have prepared three sulfonated polyphenylene-based copolymers (SPP-MP, SPP-BP, and SPP-QP) whose main chain components were the same but their sequence differed by the use of different hydrophobic monomers (monophenylene, -MP; biphenylene, -BP; and quinquephenylene, -QP, respectively). Careful investigation of the proton nuclear magnetic resonance (1H NMR) spectra suggested that the randomness of the hydrophilic component (sulfophenylene unit) was dominated by the hydrophobic component: 51 % for -MP, 32 % for -BP, and 19 % for -QP, respectively. Transmission electron microscopy (TEM) observation of the three polyphenylene ionomer membranes revealed that the lower randomness of the hydrophilic component caused a larger hydrophilic domain size in their phase-separated morphology under dry conditions. Small-angle X-ray scattering (SAXS) measurements suggested that SPP-QP, with the lowest randomness of the hydrophilic component, possessed the most pronounced periodic structure under humidified conditions.

論文

Development and application of a $$^3$$He neutron spin filter at J-PARC

奥平 琢也; 奥 隆之; 猪野 隆*; 林田 洋寿*; 吉良 弘*; 酒井 健二; 廣井 孝介; 高橋 慎吾*; 相澤 一也; 遠藤 仁*; et al.

Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10

 被引用回数:9 パーセンタイル:79.84(Instruments & Instrumentation)

We are developing a neutron polarizer with polarized $$^3$$He gas, referred to as a $$^3$$He spin filter, based on the Spin Exchange Optical Pumping (SEOP) for polarized neutron scattering experiments at Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). A $$^3$$He gas-filling station was constructed at J-PARC, and several $$^3$$He cells with long spin relaxation times have been fabricated using the gas-filling station. A laboratory has been prepared in the MLF beam hall for polarizing $$^3$$He cells, and compact pumping systems with laser powers of 30 W and 110 W, which can be installed onto a neutron beamline, have been developed. A $$^3$$He polarization of 85% was achieved at a neutron beamline by using the pumping system with the 110 W laser. Recently, the first user experiment utilizing the $$^3$$He spin filter was conducted, and there have been several more since then. The development and utilization of $$^3$$He spin filters at MLF of J-PARC are reported.

論文

Development of event-type neutron imaging detectors at the energy-resolved neutron imaging system RADEN at J-PARC

Parker, J. D.*; 原田 正英; 林田 洋寿*; 廣井 孝介; 甲斐 哲也; 松本 吉弘*; 中谷 健; 及川 健一; 瀬川 麻里子; 篠原 武尚; et al.

Materials Research Proceedings, Vol.15, p.102 - 107, 2020/05

At the RADEN instrument, we take advantage of the accurate measurement of neutron energy by time-of-flight to perform energy-resolved neutron imaging using event-type neutron imaging detectors. We are continually working to improve these detectors for better spatial resolution and shorter measurement times and, as a user facility, to improve the ease-of-use of their control and analysis software. In particular, we are actively developing a $$^{3}$$He-based gaseous micropattern detector known as the Micro-pixel chamber based Neutron Imaging Detector ($$mu$$ NID). We have recently redesigned the $$mu$$ NID control software to allow full integration into the automated experiment control system at RADEN, and we are carrying out optimization of the analysis algorithms for improved image quality and rate performance.

120 件中 1件目~20件目を表示