Computing geochemical mass transfer and water/rock ratios in submarine hydrothermal systems: implications for estimating the vigour of convection

A method of calculating chemical water/rock ratios is presented that enables the estimation of fluid velocities in open, flow‐through hydrologic systems. The approach is based on relating the gain/loss of a chemical species per kilogram of solid phase to the loss/gain of that species in the fluid phase, integrated across a specified length of the flowpath. After examining the underlying approximations of the approach using a one‐dimensional model of seawater moving through a basalt under nonisothermal conditions, the method is applied to representative zones within a two‐dimensional hydrothermal convective system. The method requires that regions within the flow system can be identified in which the direction of flow is steady for an extended period of time. Estimates of fluid velocity are spatial and temporal averages for the length of the flowpath used in the calculation. The location within the flow system and the nature of the alteration reactions determine which species can provide reliable values of the chemical water/rock ratio and useful estimates of fluid velocities. Over the length of the flowpath considered, the calculation of water/rock ratios works best when a species is controlled by a single reaction. Accurate estimates are favoured if the concentration profile of a species along the flowpath increases or decreases monotonically. If the length of the flowpath extends over more than one reaction zone, then erroneous estimates of the water/rock ratio and fluid velocity are more likely. Model calculations suggest that the quartz/silica system should provide reliable estimates for fluid velocity under a wide range of temperature and flow conditions, in particular in those regions of a system at or near quartz equilibrium, so that the aqueous silica concentration is buffered by quartz and correlated with the temperature distribution.     

Undoing Nature: The John Muir Trust's “Journey for the Wild”, the UK,Summer 2006

Abstract: I take as a point of departure for a discussion of the idea of nature the John Muir Trust's much publicised Journey for the Wild which took place in the UK during the summer of 2006. My objective is to explore how, at the same time that the “wild” was performed as a political category through the Journey, replicating the binary nature/society, prevalent norms of nature that depend on that binary, including, ironically, those of John Muir himself, were “undone”. I work with Judith Butler's (2004, Undoing Gender) ideas of “doing” and “undoing” gender and what counts as human, and her link between the articulation of gender and the human on the one hand and, on the other, a politics of new possibilities. Taking her argument “elsewhere”—unravelling what is performed as “wild” and what counts as “nature”—and using as evidence the art of Eoin Cox, the actions of journeyers, extracts from their diaries and from Messages for the Wild delivered to the Scottish Parliament, I suggest that the idea of a working wild points towards more socially just political possibilities than a politics of nature defined through a binary.     

Eland and Therianthropes in Southern African Rock Art: When Is a Person an Animal?

The interpretation of part human part animal figures is critical to the understanding of southern African rock paintings, as is the meaning ascribed to the many depictions of eland. The conventional view is that these image patterns derive from the essentially shamanistic character of the art. Here I argue that the conflation of human and animal is a far more pervasive component of southern African hunter-gatherer expressive culture and relates to the central significance of hunting in organizing man–animal and male–female relations. The eland too plays a key role in these relations. In the western Cape rock paintings the influence of this extended hunting metaphor in informing image choice appears to be paramount.L'interpretation des figures a la fois humaines et animales est fondamentale afin de comprendre les peintures rupestres sud-africaines. II en est de pour la signification des representations attribuees de l'elan. L'idee conventionnelle veut que les sujets de ces representations proviennent du caractere chamanique de l'art. Je defends ici l'idee que le melange de l'humain et de l'animal est un element nettement plus rependu de la culture expressive sud-africaine des chasseurs-cueilleurs et releve de l'organisation des relations animal/homme et homme/femme dans l'idee centrale de la chasse. L'elan joue egalemnet un role clef dans ces relations. Dans les peintures rupestres de l'Ouest du Cap, l'influence de cette metaphore elargie dans le choix d'images informatives (ayant du sens) parait etre essentielle.     

论艺术中介的管理

随着市场经济的不断深入与发展,艺术中介在艺术市场上作用越来越大并不断凸显出艺术流通中的主导地位。如何加强艺术中介的管理已到了必须从学理上进行总结与分析的时候。本试着从管理学的角度分析了艺术中介管理的原则、管理、场地选择、社会关系、资金来源、人事管理、广告宣传和品牌意识。旨在为艺术管理学做一些基础性的工作。     

中国书画艺术的乐舞精神

通过综合各家学说、考据典、辨析要义,在深入剖析中国“书画”所寓含的深刻人内涵基础上,提出了“乐舞精神”作为其主脉这一独具特色的看法,在一定意义上解决了学术界在此问题上的困惑与长期徘徊的局面。     

中国艺术考古学的奠基

艺术考古学作为一门在考古学与艺术学的边缘地带产生的交叉学科,其形成和确立顺应了考古学与艺术学学科发展的必然趋势;同样,考古学与艺术学理论的发展也为艺术考古学的建立奠定了理论和实践上的坚实基础。     

以精确之训诂 作古茂之文章——论《曾国藩家书》文论思想中的训诂观

《曾国藩家书》反映了曾国藩对子弟独特的文学教育方式,其中对训诂和辞章关系的探讨就很有价值。曾国藩学兼汉宋,不主一偏。闳通的学术胸怀使得他能客观地评定和借鉴汉宋学家的成果,并结合自己的创作经验,提出以"精确之训诂,作古茂之文章"的文学创作法,并将韩愈古文与汉魏辞赋文学传统相勾贯,以建立不囿于前期桐城派的审美观。     

‘Rearranging the ground’:1 public and private space in Belfast,Northern Ireland

This article examines imaginings and uses of place in the city of Belfast which challenge the conventionally gendered and sectarian place discourses dominating politics and society in Northern Ireland. These alternative imaginings are articulated in two artworks, ‘Home’, by Mary McIntyre, and ‘Street Signs’, by Aisling O'Beirn. I present readings of these pieces with reference to concepts of public and private which signify through socio-political, geographical and psychological orderings of space. Focusing on the construction of public and private space allows me to approach the issue of sectarian territorialisation in Belfast obliquely, while recognising its physical and psychological potency and the complexity of its operations; further, it facilitates the exploration of how gender and memory are made to matter spatially, in general and specifically in Belfast. This analytical perspective clarifies certain exclusions and oppressions inherent in the framing of space, but also offers understandings of how these may be destabilised, allowing unorthodox or marginal identities and practices to emerge as co-constituents of space.     

From Byzantine to post-Byzantine art: the painting technique of St Stephen's wall paintings at Meteora,Greece

The old katholikon of St Stephen's monastery at the Meteora (site of the most important complex of monasteries in Greece after Mount Athos) is decorated with wall paintings that date from the beginning of 17th century. In terms of style, the artistic ensemble is altogether characteristic of the period. The painting technique has been examined by means of μRaman and μFTIR spectroscopies, gas chromatography–mass spectroscopy (GC/MS), optical microscopy (OM) and scanning electron microscopy (SEM).     

Southern African San Rock Painting as Social Intervention: A Study of Rain-Control Images

Many aspects of southern African San rock art images can be understood in the light of nineteenth- and twentieth-century ethnography. San beliefs about different kinds of rain-animals and the secrecy that attended rain-control rites informed different kinds of social relations between rain-controllers themselves and between them and other people. San communities were less egalitarian than is often supposed, though ongrounds that are commonly overlooked. These points are made in reference to a hitherto unknown painted site.De nombreux aspects de lart rupestre sud-africain peuvent être compris à la lumière de documents ethnographiques des dix-neuvième et vingtième siècles. La croyance des San en différentes sortes danimaux de pluie et le secret environnant les rites de contrôle de lapluie ont révélé plusieurs types de relations sociales entre les faiseurs de pluie eux-mêmes, ainsi quentreceux-ci et les autres personnes. Les communautés san étaient moins égalitaires quon le suppose souvent, bien que cela napparaisse que sur des bases généralement négligées. Ces points sont développés en référence à un site orné jusquà présent inconnu.