For hydrated proteins, hydration waters largely contribute to the structure and properties of proteins. Therefore, the information of the dynamics of hydration waters in proteins is very important for understanding unique structure, function and crystal growth of protein. In the present study, the change in the rotational motion of water molecules around dynamical transition point (T_D〜220 K) was investigated for hydrated lysozyme using solid-state ^2H NMR. An Arrhenius-type temperature dependence of correlation time for the rotational motion of water molecules was observed above and below T_D. Although the water molecules at the surface of proteins undergo fast isotropic rotation above T_D, 180° flip becomes main motion of water molecules below T_D. Thus, the dynamics of hydrated water is found to be suppressed below T_D. The large distribution of the electric field gradient at ^2H observed below T_D indicates the glassy state of hydration water in protein.

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高分子の固体²O NMRスペクトルは構造の情報を与える化学シフトテンソルとを含んでいるために極めて複雑になり, 一般にスペクトル解析が困難である. そこで, 本研究ではスペクトルからこれらの相互作用を分離するために, 量子力学を基礎としたNMR理論を展開し, コンピューターによってスペクトル解析する方法を開発した.

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The application of high resolution NMR in mineralogical and geochemical sciences has been developed deeply in a recent decade. It gives new insights into the structures and dynamic properties of silicates, aluminosilicates and zeolites. This review will briefly summarize some fundamental aspects of the theory and experimental practice of NMR spectroscopy and application of NMR methods to mineralogical and geochemical problems. Although cited examples are limited, the detailes could be found in excellent textbooks and review papers referenced in this paper.

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High resolution two-dimensional ²⁷Al multiple-quantum magic-angle-spinning (MQMAS) NMR being capable of averaging the second-order quadrupolar interaction was applied in order to characterize the mineral matter in dry coals that have been spotlighted recently in new approach to the coal use. Octahedral aluminum compounds between kaolin and other mineral phases could be clearly distinguished by ²⁷Al MQMAS method. According as the total carbon percent increases, octahedral aluminum species tend to vary from kaolin. The ¹H→²⁷Al CP/MQMAS NMR that is a combination of cross polarization and MQMAS was also employed to evaluate the connectivity between aluminum atom and hydrogen atom. As a result, the octahedral compounds containing the linkage of Al-O-H such as kaolin and excluding the Al-O-H bond were separated by this technique. MQMAS and CP/MQMAS is very effective in characterization of inorganic matter including quadrupolar nuclei, which is particularly well suited to the analysis of clay minerals that are noncrystalline materials and present in coals although XRD is difficult to analyze the amorphous compounds.

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A new approach to structural analysis of the slag has been proposed using multinuclear solid state NMR that is capable of obtaining the structural information of each element composing the slag such as Si and Al, and effective to both crystalline and non-crystalline solid materials. In this study, we applied ¹⁹F(I=1/2), ²⁹Si(I=1/2) and ²⁷Al(I=5/2) solid state NMR to two types of steel-making slags, that differ in Al contents; 2.94 mass% (slag A) and 0.10 mass% (slag B). Measurement of ¹⁹F magic-angle-spinning (MAS) NMR enables to determine which metal among Ca, Si and Al is directly bonded to F. In these slags, F was found to be mainly coordinated by Ca. The state of SiO₄ network (Qⁿ) was estimated by ²⁹Si MAS spectra. As the result, it was found that highly condensed network of SiO₄ tetrahedron such as Q², Q³ and Q⁴ does not exist in these slag systems. In ²⁷Al NMR measurement, two-dimensional ²⁷Al multiple-quantum magic-angle-spinning (MQMAS) NMR was applied which can average the second-order quadrupolar interaction. Drastic improvement of spectral resolution at high field (16.4 T) 5QMAS experiment clarified the existence of at least 11 chemical sites of Al in slag A. From the above mentioned results, multinuclear solid state NMR is proved to be a very effective method in characterization of the slag.

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Structural analysis of inorganic matter in coal is very important, from the viewpoint of both geology and coal utilization. However, it is often difficult to assign inorganic matter from common techniques such as XRD, because some inorganic matter, i.e. clay mineral, in coal has low crystallinity.
On the other hand, solid-state NMR techniques are well suited for the analysis of noncrystalline solids such as inorganic matter in coal. Several kinds of minerals were estimated from the percentage of tetrahedral Al species that was determined by ²⁷Al MAS NMR.
In this study, we successfully developed the method for characterization of 4 minerals (kaolin, montmorillonite, muscovite, and alumina) in coal by virtue of the combination of a high magnetic field (16.4 T) and a MQMAS (Multiple Quantum Magic Angle Spinning) technique that is capable of cancel the second-order quadrupolar broadening. As a result, the structure of the inorganic matter in 26 natural coals was able to be identified. And 26 natural coals could be grouped into 6 groups according to 1-3 types of minerals combination.

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無機酸化物材料中のエトリンガイト（3CaO・Al₂O₃・3CaSO₄・32H₂O）を、固体²⁷Al NMRを用いて定量する新たな方法を確立した。²⁷Al核は四極子核（I＝5/2）であるが、エトリンガイト分子中のAl周りの対称性が良いため、非常に先鋭な6配位Alピークを示した。また、NMRの静磁場強度や試料回転周波数を最適化することによって、エトリンガイトのピークをマトリクス（高炉スラグ）由来の4配位Alピークから完全に分離できるため、適当な内標準物質（例えば硫酸カリウムアルミニウム12水和物）と共存させることによって、エトリンガイトの迅速な定量が可能となった。さらに、測定対象となるマトリクスの種類によらず、本手法が高い定量精度を持つことを実証した。

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アントラセンは硬くて脆い剛直な単結晶を構築する一方，ジハロゲンアントラセンの中には屈曲性を示す単結晶を形成する分子が存在する．例えば，9,10-ジブロモアントラセン（DBAn）と1,8-DBAnは針状結晶を形成し，2,6-DBAnは平板状結晶を形成したが，9,10-DBAn針状結晶のみが屈曲性を示した．2,6-DBAnは “edge-to-face packing” 構造，9,10-DBAnと1,8-DBAnは “face-to-face packing” 構造の分子配列となるが，屈曲性を示す9,10-DBAn針状結晶のみは “face-to-face slip-stacking” パッキング構造であった．固体¹³C NMR法から観測した¹³C核のスピン─格子緩和時間（T₁^C）の温度依存性から，9,10-DBAnの運動は，針状結晶に成長すると粉末の微結晶よりも速くなっていることが示された．

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A new approach to quantifying free magnesium oxide (f-MgO) in steelmaking slag has been proposed by using solid-state²⁵Mg nuclear magnetic resonance (NMR) spectroscopy. Although ²⁵Mg (I= –5/2) signals in solid materials often suffer from the second-order quadrupolar broadening, a quite narrow and symmetric signal of MgO is obtained in the ²⁵Mg NMR spectrum thanks to its highly symmetric Mg sites. By contrast, other Mg-containing compounds (e.g. magnesium hydroxide, diopside and åkermanite) are more or less affected by the second-order quadrupolar interaction, resulting in severe broad signals buried in the spectral noise. Therefore, the MgO peak can be only detected for steelmaking slag in the ²⁵Mg NMR spectrum without any hindrance. It is significant to select the optimum internal standard (e.g. Mg₂Si and MgS) showing the narrow ²⁵Mg signal being free from the second-order quadrupolar broadening like MgO to obtain reliable data. Accuracy of f-MgO concentration obtained by the present method has been demonstrated by using the standard samples in which f-MgO concentration is known. The advantages of the present method to quantify f-MgO in steelmaking slag, no need to dissolve slag in any solvent and detection of surface f-MgO as well as inner f-MgO of slag particles, should outweigh the disadvantages of poor signal-to-noise ratio which is surmounted by using a larger sample rotor and/or a higher magnetic field. These ideas for quantification of f-MgO by NMR should be explicated to that of free calcium oxide (f-CaO) which is responsible for hydrated expansion of steelmaking slag as well.

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架橋ポリスチレンスルホン酸系のイオン交換体内のNa⁺イオンおよび水の動的挙動についてNMR法により検討した. 水に浸したナトリウム型のイオン交換体の樹脂相内のNa⁺イオンおよび水の拡散定数をパルス磁場勾配NMR法により測定した. その結果, イオン交換体内のNa⁺イオンおよび水分子の拡散は, 水溶液中のNa⁺イオンおよび水分子の拡散に比べて5, 6倍程度遅くなっていることが判明した. 温度を変化して拡散定数を測定したところアレニウスの関係を示したので, 拡散の活性化エネルギーを求めた. さらに, Na⁺イオンおよび水のNMRの緩和時間を測定した. Na⁺イオンおよび水の緩和時間は水溶液中より短く, Na⁺イオンおよび水分子の運動が束縛されていることが明らかになった. 温度を変化して緩和時間を測定したところアレニウスの関係を示したので, 運動の活性化エネルギーを求めた.

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Chemical structure analysis of Ash for coals using solid state NMR is very difficult because of quadrupolar interation. Recent MQMAS method using high magnetic fields is able to find new chemical sites of Al except of kaolin type, as quadrupolar interation is removed. MQMAS is very powerful and useful in order to clarify the chemical structure of ash for coals.

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