Crystal Chemistry and Structure of Vesuvianite

The chemical variations of vesuvianite samples from 16 different localities, eleven in Japan, two in Norway, one in Canada, Pakistan, and Russia, have been examined using electron-microprobe analyses. For some of selected samples boron content was also examined. Results of analyses were reduced to formula unit on the basis of 50 cations excluding boron. The crystal structures of six high-symmetry (P4/nnc) vesuvianite from Japan and three low-symmetry (non-P4/nnc) vesuvianitei from Japan, Pakistan and Norway were determined by single-crystal X-ray diffraction method. The nine crystals have the following cell parameters; a = 15.568(2), 15.559(3), 15.528(3), 15.472(2), 15.564(2), 15.559(3), 15.572(2), 15.759(1), 15.563(2); c = 11.790(1), 11.797(2), 11.755(2), 11.754(1), 11.841(1), 11.826(2), 11.833(2), 11.727(1), 11.818(1) Å, respectively. The structure refinements were carried out in the space group P4/nnc, P4/n and P4nc. The final R indices for 1821, 1493, 1357, 1415, 3024, 3743, 2053, 1745 and 1873 independent reflections are 0.038, 0.031, 0.040, 0.032, 0.063, 0.082, 0.038, 0.039 and 0.060, respectively. The EXAFS method was also used to investigate the local environment of the Cu and Mn ions in the crystal structure of vesuvianites from Norway and Japan. The chemical analyses of low-symmetry vesuvianites indicate a very small amount of F and almost negligible Cl while high-symmetry one contains a considerable amount of F and Cl. The high-symmetry vesuvianite can contain Cl- ions preferentially occupying the O(10) site which is split into two sites; one is occupied by Cl- and the other by F-. The chemical compositions of high-symmetry vesuvianites are more variable than those of low-symmetry vesuvianites. The ordering of cation and vacancy in the two alternately and statistically occupied sites in a unit cell causes the lowering of the symmetry from the space group P4/nnc to P4/n or P4nc. The ordering scheme of P4nc structure is firstly confirmed in this paper. In the three low-symmetry vesuvianites, the refined site occupancy ratios for occupied (B(a) and C(a)) and vacant sites (B(b) and C(b)) are 63:37, 62:38 and 92:8 (%), respectively, and the values suggest that the ordering in these crystals is not complete. In low-symmetry vesuvianite, the satisfaction of the local charge balance on O(10) anions requires alternate occupancy of oxygen and hydroxyl with an associated hydrogen bond and ordering sequences of cations. In Cl- and F-bearing high-symmetry vesuvianite, on the other hand, occupying of Cl and F in O(10) sites interrupts the sequences of cations and vacancies along the fourfold rotation axes. Boron-bearing vesuvianite from Russia contain more Mg and less Al than those of boron-free vesuvianite. Boron occupies the additional cation sites, tetrahedrally coordinated site at the 8h position and triangularly coordinated site at the 2a position. The excess of the scattering power at these sites derived from the measured amounts of boron indicates that some elements other than boron should occupy in boron positions

On the Listening to Buddha’s Words with Reverence

This paper focuses on the fifth chapter of the Vyākhyāyukti by Vasubandhu, a Buddhist thinker who was active in the fourth and fifth centuries in Northwestern India, and a commentary on that work, the Vyākhyāyuktiṭīkā by Guṇamati. In this chapter, Vasubandhu deals with the issue of how those who preach about the Buddha’s words should teach about them and how those who listen to those teachings should study them. Vasubandhu explains that ‘listening to the Buddha’s words with reverence’ is critical as the first step of Buddhist practice. The source for this position of Vasubandhu’s can be found in the Arthavistara-dharmaparyāya in the Dīrghāgama of the Sarvāstivāda. Vasubandhu argues that the first step of Buddhist practice is listening to the Buddha’s words with reverence based on the third of sixteen methods for listening to the Buddha’s words that are described in the fifth section of that scripture. Why is reverence necessary when listening to the Buddha’s words? Vasubandhu uses the famous metaphor of three kinds of vessels in answering this question. This metaphor respectively likens (1) a person who does not listen to the teachings, (2) a person who listens to the teachings but misunderstands them, and (3) a person who listens to the teachings but fails to remember them to (1) an upside-down vessel, (2) a dirty vessel, and (3) a vessel with a hole in it. That is to say, Vasubandhu is pointing to the fact that if a listener lacks respect for the preacher, they will (1) not try to listen carefully to the teachings, (2) misunderstand them, or (3) forget them. Vasubandhu also uses this metaphor in his Pratītyasamutpādavyākhyā, which was written after the Vyākhyāyukti. This metaphor also appears frequently in Tibetan Buddhist literature in the works of figures such as Bu ston rin chen grub and Tsong kha pa. The position that Vasubandhu took regarding the importance of listening to the Buddha’s words with reverence was extremely influential and came to be broadly held in the Buddhist traditions of both India and Tibet after the fifth century

薬剤抵抗性メカニズムとしてのc-Srcの逆説的活性化

京都大学新制・課程博士博士(医科学)甲第23425号医科博第130号新制||医科||9(附属図書館)京都大学大学院医学研究科医科学専攻(主査)教授 萩原 正敏, 教授 戸井 雅和, 教授 武藤 学学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

The role of cramming for examinations and its impact on the use of learning strategies : A comparison between Japanese students and Singaporean students

Students use variety of learning strategies to achieve their perceived learning goals. These strategies range from memory-oriented learning typical of cramming for objective tests, to deep-processing strategies characteristic of what we have defined as "authentic learning." Students\u27 choices of learning strategies depend not only on the style of teaching and assessment, but also on students\u27 perceptions of their learning goals. This paper intends to show that cramming for high-stakes test can foster use of psychologically sound and creative learning strategies such as meaningful learning, structural learning, and metacognitive judgment. The larger the amount of content knowledge students must learn in order to pass a high-stakes exam, the more sophisticated the learning strategies need to be. Our data from Japanese students and Singaporean students show the effect of cramming for high-stakestest foster developmental changes in students\u27 learning strategies