Fe-C and Fe-H systems at pressures of the Earth's inner core

The solid inner core of the Earth is predominantly composed of iron alloyed with several percent Ni and some lighter elements, Si, S, O, H, and C being the prime candidates. There have been a growing number of papers investigating C and H as possible light elements in the core, but the results are contradictory. Here, using ab initio simulations, we study the Fe-C and Fe-H systems at inner core pressures (330-364 GPa). Using the evolutionary structure prediction algorithm USPEX, we have determined the lowest-enthalpy structures of possible carbides (FeC, Fe2C, Fe3C, Fe4C, FeC2, FeC3, FeC4 and Fe7C3) and hydrides (Fe4H, Fe3H, Fe2H, FeH, FeH2, FeH3, FeH4) and have found that Fe2C (Pnma) is the most stable iron carbide at pressures of the inner core, while FeH, FeH3 and FeH4 are stable iron hydrides at these conditions. For Fe3C, the cementite structure (Pnma) and the Cmcm structure recently found by random sampling are less stable than the I-4 and C2/m structures found here. We found that FeH3 and FeH4 adopt chemically interesting thermodynamically stable structures, in both compounds containing trivalent iron. The density of the inner core can be matched with a reasonable concentration of carbon, 11-15 mol.percent (2.6-3.7 wt.percent) at relevant pressures and temperatures. This concentration matches that in CI carbonaceous chondrites and corresponds to the average atomic mass in the range 49.3-51.0, in close agreement with inferences from the Birch's law for the inner core. Similarly made estimates for the maximum hydrogen content are unrealistically high, 17-22 mol.percent (0.4-0.5 wt.percent), which corresponds to the average atomic mass in the range 43.8-46.5. We conclude that carbon is a better candidate light alloying element than hydrogen.Comment: Published in Physics-Uspekhi: full text will soon appear at http://ufn.ru/en/articles/2012/5/c/ (currently, only abstract is available

Typological features of Chinese culture in the Ming Dynasty (1398-1644)

The article deals with the typology of Chinese culture during the Ming Dynasty (1398-1644). Study of the cultural complex of this period is important because Chinese tradition, characterised by cultivation of a symbolic world view, had entered its final stage, but still had not yet been subject to conscious "conservation" by the authorities. In the Ming Dynasty, spiritual and artistic synthesis, cultivated by a symbolic world view, reached perfection but also showed signs of stagnation, which became determinative in the following centuries. The obliteration of symbolic reality and the replacement of a symbolic world view by a naturalistic one characterises the development of Chinsese cultural process in the Modern age. This study of symbolic reality is based on functionalistic methodology, which proposes that the roots of symbolism can be found in the premises of human activity, which correspond to the history of sociality as a set of moments of experience. The Universe in the Chinese tradition has organic integrity; a man is equal to the cosmic forces of heaven and earth and occupies a central place among them. Chinese behavioural norms operate according to specific limitations: every deed and action of the individual is evaluated in terms of etiquette and morality. Thus naturalism, vitalism, holism, humanism and ethical imperative form the philosophical and cultural foundations of the Chinese world view. From this it follows that a correlated - rather than a cause-and-effect - principle is typical of Chinese culture, capturing the relationship between phenomena, revealing their likeness or kinship. A condition of attribution to a particular type means belonging to the positive or negative sphere of being (yang-yin), to one or another archetype. From this follows the idea of transformation, providing a basis for further specialisation and complexity within the artistic experience

Typological features of Chinese culture in the Ming Dynasty (1398-1644)

The article deals with the typology of Chinese culture during the Ming Dynasty (1398-1644). Study of the cultural complex of this period is important because Chinese tradition, characterised by cultivation of a symbolic world view, had entered its final stage, but still had not yet been subject to conscious "conservation" by the authorities. In the Ming Dynasty, spiritual and artistic synthesis, cultivated by a symbolic world view, reached perfection but also showed signs of stagnation, which became determinative in the following centuries. The obliteration of symbolic reality and the replacement of a symbolic world view by a naturalistic one characterises the development of Chinsese cultural process in the Modern age. This study of symbolic reality is based on functionalistic methodology, which proposes that the roots of symbolism can be found in the premises of human activity, which correspond to the history of sociality as a set of moments of experience. The Universe in the Chinese tradition has organic integrity; a man is equal to the cosmic forces of heaven and earth and occupies a central place among them. Chinese behavioural norms operate according to specific limitations: every deed and action of the individual is evaluated in terms of etiquette and morality. Thus naturalism, vitalism, holism, humanism and ethical imperative form the philosophical and cultural foundations of the Chinese world view. From this it follows that a correlated - rather than a cause-and-effect - principle is typical of Chinese culture, capturing the relationship between phenomena, revealing their likeness or kinship. A condition of attribution to a particular type means belonging to the positive or negative sphere of being (yang-yin), to one or another archetype. From this follows the idea of transformation, providing a basis for further specialisation and complexity within the artistic experience

Typological features of Chinese culture in the Ming Dynasty (1398-1644)

The article deals with the typology of Chinese culture during the Ming Dynasty (1398-1644). Study of the cultural complex of this period is important because Chinese tradition, characterised by cultivation of a symbolic world view, had entered its final stage, but still had not yet been subject to conscious "conservation" by the authorities. In the Ming Dynasty, spiritual and artistic synthesis, cultivated by a symbolic world view, reached perfection but also showed signs of stagnation, which became determinative in the following centuries. The obliteration of symbolic reality and the replacement of a symbolic world view by a naturalistic one characterises the development of Chinsese cultural process in the Modern age. This study of symbolic reality is based on functionalistic methodology, which proposes that the roots of symbolism can be found in the premises of human activity, which correspond to the history of sociality as a set of moments of experience. The Universe in the Chinese tradition has organic integrity; a man is equal to the cosmic forces of heaven and earth and occupies a central place among them. Chinese behavioural norms operate according to specific limitations: every deed and action of the individual is evaluated in terms of etiquette and morality. Thus naturalism, vitalism, holism, humanism and ethical imperative form the philosophical and cultural foundations of the Chinese world view. From this it follows that a correlated - rather than a cause-and-effect - principle is typical of Chinese culture, capturing the relationship between phenomena, revealing their likeness or kinship. A condition of attribution to a particular type means belonging to the positive or negative sphere of being (yang-yin), to one or another archetype. From this follows the idea of transformation, providing a basis for further specialisation and complexity within the artistic experience

Typological features of Chinese culture in the Ming Dynasty (1398-1644)

The article deals with the typology of Chinese culture during the Ming Dynasty (1398-1644). Study of the cultural complex of this period is important because Chinese tradition, characterised by cultivation of a symbolic world view, had entered its final stage, but still had not yet been subject to conscious "conservation" by the authorities. In the Ming Dynasty, spiritual and artistic synthesis, cultivated by a symbolic world view, reached perfection but also showed signs of stagnation, which became determinative in the following centuries. The obliteration of symbolic reality and the replacement of a symbolic world view by a naturalistic one characterises the development of Chinsese cultural process in the Modern age. This study of symbolic reality is based on functionalistic methodology, which proposes that the roots of symbolism can be found in the premises of human activity, which correspond to the history of sociality as a set of moments of experience. The Universe in the Chinese tradition has organic integrity; a man is equal to the cosmic forces of heaven and earth and occupies a central place among them. Chinese behavioural norms operate according to specific limitations: every deed and action of the individual is evaluated in terms of etiquette and morality. Thus naturalism, vitalism, holism, humanism and ethical imperative form the philosophical and cultural foundations of the Chinese world view. From this it follows that a correlated - rather than a cause-and-effect - principle is typical of Chinese culture, capturing the relationship between phenomena, revealing their likeness or kinship. A condition of attribution to a particular type means belonging to the positive or negative sphere of being (yang-yin), to one or another archetype. From this follows the idea of transformation, providing a basis for further specialisation and complexity within the artistic experience