著者

坂本 昌巳 三野 孝 藤田 力

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.47, no.2, pp.135-139, 2005-04-27 (Released:2010-09-30)

参考文献数

20

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Synthesis of optical active compounds from achiral or racemic materials is one of the most impressive studies in organic chemistry. Here we provide two new technique of generation of optical activity without anyl outside chiral source. One is the breaking of chiral symmetry of axially chiral materials via racemization-preferential crystallization method. Another involves the asymmetric reaction using the frozen chirality generated by chiral crystallization of achiral materials.

著者

相澤 俊 安藤 寿浩

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.2, pp.160-166, 1996-04-30 (Released:2010-09-30)

参考文献数

16

被引用文献数

1

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Surface vibration of CVD-grown diamond surface is measured by HR-EELS. Hydrogen is adsorbed on the sp3-hybridized carbon. On the (001) 2×1 surface, one C-H stretching vibration appears consistently with the dieter-chain model. On the (111) 1×1 surface, two C-H stretching modes appear, which suggests methyl termination model. But the phonon dispersion in the low energy region is well explained by the monohydride termination model. Uniformity of the surface should be checked to discuss this inconsistency. Hydrogen exchange with the gas-phase and the hydrogen desorption/adsorption processes are also investigated.

著者

阿部 洋 大嶋 建一

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.2, pp.151-159, 1996-04-30 (Released:2010-09-30)

参考文献数

48

被引用文献数

1

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A characteristic waiting time appears at fixed temperature above Tc or Ms for elements, alloys and polymers, where Tc is the usual first-order phase transition temperature and Ms is the normal martenstic phase transition temperature. This waiting time is called incubation time and related with the nucleation probability derived from a nucleation barrier. That is why nucleation process is regarded as thermal activated process at the non-equilibrium state. In particular, such a long incubation time of In-Tl alloys has a good agreement with experimental results by using Roitburd method. Furthermore, detailed and accurate experiments enable us to be aware that two dimensional growth occurs above Tp, where peculiar temperature, Tp, controls the time development of diffraction patterns and appears above Ms in this system.In contrast to soft phonon model, incubation time is essential property of the first-order phase transition and the key to resolve nucleation and growth process.

著者

竹中 章郎

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.48, no.5, pp.311-319, 2006-10-31 (Released:2010-09-30)

参考文献数

4

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As an easy technique for phase determination in X-ray analysis of macromolecular crystals, the molecular replacement method is widely used. Available computer programs are highly sophisticated to user friendly so that users can use them without knowledge on the theoretical backgrounds. To develop the technique to more powerful tool, as well as to resolve individual problems in special cases, it is essential to understand the details of the backgrounds. Here the theories of the method with the historical backgrounds, its availability and capability, practical usage and trouble shooting will be described.

著者

金原 数 西郷 和彦

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.6, pp.414-420, 1996-12-30 (Released:2010-09-30)

参考文献数

14

被引用文献数

1 1

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X-ray crystallographic studies were carried out for conglomerate salts, racemic-compound salts, and enantiomerically pure salts of chiral primary amines with achiral mono-carboxylic acids. The crystal structures of the conglomerate salts revealed that these crystals can be regarded as being a supramolecular assembly of a characteristic columnar hydrogen-bond network, in which the ammonium cations and the carboxylate anions are aligned around a twofold screw axis (21-column) . On the other hand, the crystal structures of the racemic-compound salts could be roughly classified into two types. One type is a crystal consisting of 21columns; the other type is a crystal consisting of a different type of columnar hydrogen-bond network, in which the ammonium cations and the carboxylate anions are related by inversion centers (i-column) .These results suggest that both the formation and the assembly of 21columns are essential in the formation of conglomerates for these salts.

著者

大場 茂

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.3, pp.201-207, 1996-06-30 (Released:2010-09-30)

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Several cautions concerning the assignment of Bravais lattice and space group are presented for beginners in X-ray crystal structure analysis.

著者

青木 克之

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.23, no.6, pp.309-327, 1981-11-30 (Released:2010-09-30)

参考文献数

29

被引用文献数

12 20

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Divalent metal ions are required virtually in every stage of genetic information transfer, and have profound effects on the structures and functions of nucleic acids. This article reviews the current developments of X-ray diffraction studies of metal ion interactions with nucleic acid constituents. The following important findings and topics are briefly presented ; metal binding sites, metal binding effects on the structural dimensions and conformations of nucleic acid constituents, molecular structures of metalnucleotide complexes, metal binding mode in ternary metal ion-nucleotide complexes containing aromatic heterocyclic ligands, which have been studied as a simple model for nucleic acid-metalion-enzyme system, and binding modes of anti-tumor agents, cisammine platinum (II) complexes with nucleic acids.

著者

杉本 宏 永野 真吾 城 宜嗣

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.48, no.6, pp.418-423, 2006-12-25 (Released:2010-09-30)

参考文献数

16

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Over a past few years, we have determined crystal structures of several metal-containing oxygenases including indoleamin-2, 3-dioxygenase and some P450s which have interesting chemistry and play important roles in metabolism. Molecular mechanisms of these oxygenases are discussed based on the crystal structures.

著者

笹田 義夫 島内 浩喬

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.17, no.1, pp.110-122, 1975-02-20 (Released:2010-09-30)

参考文献数

58

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From the structural-chemical point of view, the ‘non-benzenoid aromatic compounds’ are reviewed. Hückel's (4n+2) rule has been proved by the X-ray analysis of several annulenes. It was pointed out, however, that resonance energies of non-alternant hydrocarbons are overestimated. Structural studies on the conjugated odd-membered ring systems have shown that these systems are very sensitive to various kinds of interactions, electronic, steric and intermolecular hydrogen bonding effects. The characteristic chemical and physical behaviours can be reasonably related to the structures.

著者

堀内 弘之

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.43, no.2, pp.137-147, 2001-04-25 (Released:2010-09-30)

参考文献数

20

著者

大場 茂

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.37, no.1, pp.62-68, 1995-02-28 (Released:2010-09-30)

参考文献数

20

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Nitrite ion is a well-known ligand which shows linkage isomerism. The photo-isomerization in the solid state is governed by at least two factors: (a) electronic effect by coexisting ligands, and (b) reaction cavity of the nitro group. Recent X-ray study has revealed that the nitro-nitrito photo isomerization in a crystal is severely governed by intermolecular steric restrictions.

著者

入戸野 修

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.57, no.2, pp.134-135, 2015

著者

吉原 涼子 森 一樹 西山 繁 山村 庄亮 大場 茂 伊藤 義勝

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.40, pp.62-62, 1998

著者

山本 直紀

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.39, no.4, pp.279-288, 1997-08-30 (Released:2010-09-30)

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This article gives fundamentals of analyzing electron diffraction patterns for persons who start to use an transmission electron microscope.

著者

Masayuki IMAI

出版者

The Crystallographic Society of Japan

雑誌

Nihon Kessho Gakkaishi (ISSN:03694585)

巻号頁・発行日

vol.42, no.2, pp.129-138, 2000-04-30 (Released:2010-09-30)

参考文献数

22

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In this lecture I explain basic concepts of small angle scattering and their application to structural analysis of polymer materials. The small angle scattering plays an important role to elucidate fundamental problems in polymer physics.

著者

永嶋 伸也

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.35, no.6, pp.381-391, 1993-12-28 (Released:2010-09-30)

参考文献数

42

被引用文献数

4 6

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The crystal structures of polymorphisms of free amino acids have been reviewed. The polymorphisms were classified into three types: The first, including DL-methionine, DL-norleucine and DL-a-amino-butyric acid, has polymorphs of different packing arrangement of molecular double layers which is rigidly bound by hydrogen bonds. In this type, the polymorphs can interconvert in solid state by temperature. The second type, glycine, L-cystine and L-histidine, has polymorphs in which hydrogen bonding schemes are different although molecular conformations are similar. The third type, L-cystein, L-aspartic acid and L-glutamic acid, has polymorphs with different hydrogen bonding schemes and different molecular conformations. In this type, metastable form converts irreversibly to stable form by solvent-mediated transformation mechanism.

著者

八木 亜希子 水島 恒裕 佐藤 孝雄 森本 幸生 月原 冨武 渋谷 明宏 後藤 寿夫 田中 啓二 市原 明

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.35, pp.102-102, 1993

著者

古谷野 哲夫

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.56, no.5, pp.319-322, 2014

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Chocolate consists of solid particles such as cocoa, sugar, and milk solids which are dispersed in a continuous fat phase. The major fat in chocolate is cocoa butter, and it is crystallized at room temperature, so chocolate is a food which we eat crystals. Therefore, fat crystals play a great role in chocolate quality and storage stability. In this paper, polymorphism of cocoa butter and the transformation of polymorphic forms are reviewed including recent results.

著者

下村 理

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.32, no.5, pp.239-253, 1990

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10 years have past since a system for experiments under high pressure and temperature using synchrotron radiation, named MAX80, was planned to be installed in the Photon Factory. Many scientifically interesting activities in various fields have been done using MAX80. The development of this system has been performed intensively by high pressure community of Japan in cooperation with synchrotron radiation group. The process of the development, outline of the system and typical applications are described.

著者

堀 哲哉 森山 英明 五十嵐 教之 赤沼 哲史 池崎 章 広瀬 雷太 大島 泰郎 田中 信夫

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, pp.93-93, 1996