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1.
A collection of 31 glass fragments, dated to the 3rd to 7th century AD and excavated in Veh Ardašīr, (modern Iraq), were analysed for their Sr and Nd isotopic compositions with the aim of deepening our knowledge on glass circulating within central Mesopotamia during Sasanian times and to highlight the merits of isotope ratios for the definition of the production scenery. Based on the elemental composition of the samples, two groups related to the exploitation of different plant ashes were previously distinguished, and also a change in the silica source in the course of the 4th century AD emerged. The determination of isotopic distributions of Sr and Nd offers a deeper insight. The 87Sr/86Sr isotope ratio, together with the Sr elemental concentration, confirms this use of different plant ashes, and permits one to distinguish distinct glass batches, although the isotopic Sr signature does not allow us to highlight evidences of different provenances for the samples of different composition. Moreover, the 143Nd/144Nd isotope ratio suggests the use of sands belonging to a common geological area, and also allows the identification of a set of samples that were possibly produced exploiting a further different sand source. As a whole, Sr and Nd isotope ratio values for the samples considered, i.e. 87Sr/86Sr = 0.70833 to 0.70916 and ?Nd = −8.69 to −4.98, differ from the published isotopic data on middle Eastern glass samples and can therefore define a characteristic Sr–Nd signature for plant-ash Sasanian glass excavated in Veh Ardašīr.  相似文献   

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Chemical analysis, optical absorption spectroscopy and mathematical modelling of high temperature viscosity have been carried out on five 1st–2nd century AD Roman blue-green bottle glass fragments from Coppergate, York. Modelled viscosities indicate remarkable consistency within the sample set studied and support the suggestion that temperatures of ∼1000–1150 °C were required to remelt these glasses and to provide suitable viscosities for forming articles. Iron redox ratios (Fe2+/ΣFe), analysed SO3 contents and the absence of characteristic Fe3+–S2− amber absorption bands suggest that melting conditions for all studied glasses were mildly, rather than strongly, reducing (estimated pO2 ≈ 10−1–10−6 bar). These furnace conditions are consistent with the effects of combustion gases and carbonaceous matter contained in the raw materials.  相似文献   

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Whether Americans have “sorted” into politically like-minded counties and to what extent is hotly debated by academic and journalists. This paper examines whether or not geographic sorting has occurred and why it has occurred using a novel, dynamic analysis. Our findings indicate that geographic sorting is on the rise, but that it is a very recent phenomenon. In the 1970s and 1980s, counties tended to become more competitive, but by 1996 a pattern of partisan sorting had emerged and continued through the present. Results suggest this pattern is driven by Southern re-alignment and voting behavior in partisan stronghold counties. Lastly, we find evidence that migration can drive partisan sorting, but only accounts for a small portion of the change.  相似文献   

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Based on William Morris Davis’ great Transcontinental Excursion of 1912, this article assesses and reviews the Geography by Rail® program (GbR) – a unique, short-term, field-based study abroad experience that takes an uncommon-in-the-US approach to international exploration and fieldwork, incorporating on-the-ground, regional geography-based learning experiences. Though it could be used as such, this is not intended as a “how-to” article, but instead, an examination of how the program’s alternative approach to short-term, field-based learning increases student engagement, enlivens the discipline of geography by championing the regional geography approach, and bridges the physical-human divide in geography. Examples are given of assessment techniques, relevant skills gained by student participants, student feedback received, and potential limitations of such a program. Our main goal rests in demonstrating that by being in the landscape, practicing in it, students often gain a perspective not achievable in the traditional classroom setting. In the regional and romantic geography sense, favoring breadth of learning over depth, we further argue that GbR represents a novel way to accomplish this important-yet-not-often-fostered and, oddly and unfortunately, difficult-to-find-in-geography concept.  相似文献   

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This article argues that the Bush strategy of 'spectacle war' is caught in an earlier Cold War paradigm primarily aimed at influencing American public opinion and that it fails to take into account the reality of the current global context, especially with regard to changes in the nature of sovereignty and in the role of military force. The United States, in its current posture, has the capability to be very destructive but is much less able to do 'compellance', that is to say, to impose its will on others. In particular, the current strategy cannot defeat terrorism.
The article draws up a typology of different visions of how American power is, or should be, exercised based on different assumptions about sovereignty and military power. It concludes that American power can only be exercised constructively within a cosmopolitan framework. Such a framework is best suited to the containment, and possibly, the defeat of terrorism. It would contribute both to global economic growth and to American democracy.  相似文献   

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Tang sancai is one of the most important types of Chinese ceramics. To determine the provenance of Tang sancai is important to study ancient trade and other issues. In this paper we compare ICP-MS trace elements and TIMS Sr–Nd isotopes of visibly similar Tang sancai from two major production centres Gongxian and Yaozhou. The variation in contents/ratios of many of >40 trace elements is small for samples from Gongxian, yet is considerably bigger for that from Yaozhou. However, the variation in 87Sr/86Sr and 143Nd/144Nd isotopic ratios is very small for samples from both places. Gongxian and Yaozhou samples have distinctive Sr–Nd isotopic and trace element features despite their similarity in major elements, and these analysis data can be interpreted with geochemistry, indicating that Sr and Nd isotopes have great potential in ceramic provenance studies. The distinct characterisation of these samples provides valuable criteria for identifying provenance of Tang sancai of uncertain origin. Two modern fakes are also analysed, and they can as well be distinguished from antique Tang sancai using above criteria.  相似文献   

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Glass shards from post-contact contexts at the Northern Tsimshian site of Ginakangeek, on the north coast of British Columbia Canada, are identifiable as expedient tool artifacts through analysis of usewear patterns. In this study, we have examined the nature of glass and argued that its mineralogical properties make it analogous to other lithic materials. Although other researchers have found evidence of a lithic-like industry of glass artifacts based on macroscopic features, we have demonstrated that expedient artifacts are identifiable even in the absence of macroscopic traits, through low-power magnification of usewear. We have also tested this thesis against the possibility that microscopic usewear-like patterns were the product of fragmentation or post-depositional effects, and argued that a suite of usewear traits correlates only with use activity. Our experimental suite of glass artifacts indicates that specific actions (such as cutting, scraping, sawing, and chiseling) and the relative hardness of specific substrates produce particular usewear patterns. A number of potential explanations are considered for the appearance of such an industry on the Northwest Coast more than a century after contact with Europeans.  相似文献   

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One of the frequently encountered issues in ancient Greek dietary reconstructions through isotope analyses has been the apparent unimportance of fish protein in human diets. The significance of this observation is amplified by the abundant ichthyofaunal remains, iconographic evidence and literary information on fish and fishing, pertaining to almost all sites and time periods of Greek antiquity. In this project, we measured for the first time isotopes from a large number of fish bones from Greek sites dating from the Mesolithic to the Classical times, aiming to investigate whether this absence is an artefact of the methodology or whether it reflects a reality of restricted fish consumption. Results show that regional trends are stronger that temporal ones in fish isotope values. The range of values overlaps with terrestrial resources, making it difficult or impossible to reject fish consumption based on isotope data alone. This variability proposes a reconsideration of the amount of fish in ancient Greek diets specifically for each site and amplifies the importance of interdisciplinary studies, especially for regions with variable ecological resources.  相似文献   

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In his commentary on Aristotle’s Rhetoric al-Fārābī harmonizes Plato and Aristotle in terms of philosophic education by ordering Aristotle’s eight logical works onto Plato’s famous image of the cave. He represents the way out of the cave with Aristotle’s four logical works of ascent (Categories, On Interpretation, Prior Analytics, and Posterior Analytics) and the return into the cave through Aristotle’s four logical works of the descent (Topics, Sophistical Refutations, Rhetoric, and Poetics). Al-Fārābī’s image of ascent and descent also alludes to Socrates’ conception of protreptic education in Book VII of the Republic. In essence, protreptic education consists in the Socratic art that freely turns the soul from the images and political interpretations of things to being itself. In this essay I argue that for al-Fārābī the four logical works of ascent guide the soul to free itself from its habituations so as to contemplate real beings, particularly the good of one’s own soul and the souls of one’s fellow citizens. Yet the ruler needs to use the arts of “descent,” as demonstrated by Thrasymachus, in order to rule the city well. The way of Socrates consists of the logical methods used to come to possess knowledge of being, while the way of Thrasymachus comprises the methods of persuasion to habituate citizens and protect the philosophic quest for the truth. Al-Fārābī, I conclude, combines the way of Socrates and the way of Thrasymachus in order to show that both ways are useful and necessary for good governance.  相似文献   

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The paper reports and discusses data obtained by archaeological and archaeometric studies of glass vessels and tesserae from the qasr of Khirbet al-Mafjar (near Jericho, Palestine). Archaeological contextualisation of the site and chrono-typological study of glass vessels were associated to EPMA and LA–ICP–MS analyses, performed to characterise the composition of the glassy matrix (major and minor components as well as trace elements). Analyses allowed achieving meaningful and intriguing results, which gain insights into the production and consumption of glass vessels and tesserae in the near East during the Umayyad period (seventh–eighth centuries). Within the analysed samples, both an Egyptian and a Levantine manufacture have been identified: such data provide evidence of a double supply of glass from Egypt and the Syro-Palestinian coast in the Umayyad period occurring not only in the glassware manufacture but also in the production of base glass intended to be used in the manufacture of mosaic tesserae. Thus, the achieved results represent the first material evidence of a non-exclusive gathering of glass tesserae from Byzantium and the Byzantines in the manufacture of early Islamic mosaics.  相似文献   

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Books reviewed in this article:
John Hines, Karen Høilund Nielsen and Frank Siegmund (eds), The Pace of Change. Studies in Early–Medieval Chronology.
Catherine E. Karkov, Kelley M. Wickham–Crowley and Bailey K. Young (eds), Spaces of the Living and the Dead: An Archaeological Dialogue.
Sam Lucy, The Early Anglo–Saxon Cemeteries of East Yorkshire. An Analysis and Reinterpretation.
Elizabeth O'Brien, Post–Roman Britain to Anglo–Saxon England: Burial Practices Reviewed.
Nick Stoodley, The Spindle and the Spear. A Critical Enquiry into the Construction and Meaning of Gender in the Early Anglo–Saxon Burial Rite.  相似文献   

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There is today a global recognition that we live in an ‘urban age’ of near‐planetary urbanization where cities are at the forefront of all sorts of agendas. Yet little attention is offered to the active role of cities as political drivers of the urban age. There might today be more than two hundred ‘city networks’ globally, with thousands of para‐diplomatic connections actively defining relations between cities, international organization and corporate actors. This actively networked texture of the urban age shapes all areas of policy and, not least, international relations, and holds much promise as to possible urban solutions to global challenges. Based on an overview of a representative subset of this mass of city‐to‐city cooperation (n=170), this article illustrates the landscape of city networking, its issue areas and institutional shapes, and its critical features. As we argue, city networks today are faced by a crucial challenge: while trying to overcome state‐centric ‘gridlocks’ cities are, at the same time, building both political–economic as well as very material ‘lock‐ins’. We need to pay serious attention to this impact of city diplomacy in international affairs, developing a greater appreciation of the path dependencies and responsibilities this diplomatic activity purports.  相似文献   

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