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51.
Traditions and transitions in Korean bronze technology 总被引:1,自引:0,他引:1
Metallurgical examination of Korean bronze artifacts shows that a technical tradition based on casting and use of leaded high-tin alloys was established in Korea at the early stages of bronze use. After the subsequent discovery of quenching methods that suppress formation of the brittle δ phase, new thermo-mechanical techniques were introduced between the 7th and 10th centuries AD. Lead-free alloys were used, and tin contents near that of the peritectic point in the Cu–Sn phase diagram were chosen. Leaded high tin alloys continued in use, but only in cast objects, and with significant composition variation. The unique conditions during the time of innovation suggest that the transition to new metallurgical techniques was gradually achieved through domestic technical innovation inspired by external influences. 相似文献
52.
Eregzen Gelegdorj Amartuvshin Chunag Robert B. Gordon Jang-Sik Park 《Journal of archaeological science》2007
Metallurgical study of seven cast iron artifacts recovered from sites of the former Xiongnu (BC 3rd to AD 1st), Turk (AD 6th to 8th), Khitan (AD 10th to 12th), and Mongolian empires (AD 12th to 15th) shows that the earlier Xiongnu and Turk artifacts were made of cast iron alloys of near eutectic composition. The later Khitan and Mongol objects had greatly reduced carbon content in the range of ultrahigh carbon steel rather than cast iron, and contained more than 0.5 mass % silicon as an alloying element. Inclusions high in sulfur, phosphorus or silicon are also present. These differences suggest that Mongolia experienced a technical transition a few centuries before the establishment of the Mongolian empire, which is in agreement with some written accounts. The microstructures of the cast iron artifacts are compared with the related archaeological and documentary evidence. The results suggest that the use of fossil coal in smelting and the state policy of controlling iron production were the major factors responsible for the transition. 相似文献
53.
In this paper we ask how a shrinking city responds when faced with a perforated urban fabric. Drawing on Manchester's response to its perforated eastern flank —and informed by a parallel study of Leipzig—we use the city's current approach to critique urban regeneration policy in England. Urban renaissance holds out the promise of delivering more sustainable—that is more compact, more inclusive and more equitable—cities. However, the Manchester study demonstrated that the attempt to stem population loss from the city is at best fragile, despite a raft of policies now in place to support urban renaissance in England. It is argued here that Manchester like Leipzig is likely to face an ongoing battle to attract residents back from their suburban hinterlands. This is especially true of the family market that we identify as being an important element for long-term sustainable population growth in both cities. We use the case of New East Manchester to consider how discourses linked to urban renaissance—particularly those that link urbanism with greater densities—rule out some of the options available to Leipzig, namely, managing the long-term perforation of the city. We demonstrate that while Manchester is inevitably committed to the urban renaissance agenda, in practice New East Manchester demonstrates a far more pragmatic—but equally unavoidable—approach. This we attribute to the gap between renaissance and regeneration described by Amin et al. (Cities for the Many Not for the Few. Bristol: Policy Press, 2000) who define the former as urbanism for the middle class and the latter as urbanism for the working class. While this opportunistic approach may ultimately succeed in producing development on the ground, it will not address the fundamental, and chronic, problem; the combination of push and pull that sees families relocating to suburban areas. Thus, if existing communities in East Manchester are to have their area buoyed up—or sustained—by incomers, and especially families, with greater levels of social capital and higher incomes urban policy in England will have to be challenged. 相似文献
54.
Alan M. W. Porter 《International Journal of Osteoarchaeology》1995,5(4):305-323
The femur remains an important bone in palaeoanthropology and this paper reports various analyses of measurements taken from long-cassette radiographs of adult femurs of a reference population from the south of England (n=81, males 33, females 48). Discriminant analysis confirmed that the male femur is usually larger than the female femur, and that a femur may be sexed with some confidence. Discriminant scores have been derived to permit estimates to be made, from the whole or a part of a femur, of the probability of the male gender. Outcomes from a principal component analysis suggest: that the female proximal femur is a morphological unit; that neck length and shaft length are dissociated and there is no common factor representing linearity; and that the male bicondylar width is anomalous, a finding that is confirmed by other analyses. An estimate of the robusticity of the complete female, but not male, bone may sometimes be made from a proximal fragment. The robusticity of the complete bone may be made confidently from the shaft for both genders. The two width variables relating to a distal fragment cannot be used to predict the robusticity of the complete bone for either gender. A method of defining the position of the waist in terms of displacement in deciles down the shaft is described. The position of the waist seems to have a bimodal distribution. The positive association between age and distal displacement may be due to remoulding of the shaft with age or to a cohort (generational) effect. There is a weak correlation between a small neck–shaft angle and the distal displacement of the waist, two archaic phenotypic traits. Ten statements in the literature relating to the femur have been examined and tested; six are confirmed and four are unconfirmed, and it is suggested that there is a need for further studies relating to the morphology of the femur. 相似文献
55.
In September 1988 archaeologists and students from the Program in Maritime History and Underwater Research at East Carolina University (PMHUR) identified the remains of an early shipwreck during a survey of the Western Ledge Reefs carried out for the Bermuda Maritime Museum (BMM). Structural material exposed at the wreck site proved to be a section of lower hull containing the keel, hull planking, frames, and a portion of the keelson that included a mast-step. In order to recover the archaeological record preserved at the site, the BMM applied for, and received, a licence from the Receiver of Wreck. As work at the site intensified, a prior claim to the wreck was discovered. Discovery of that claim ultimately led to a co-operative agreement between Brian Malpas, Donald Canton and the BMM that permitted on-site investigation to continue. During 1989 and 1990, the site was excavated by the Museum's underwater archaeological staff, the staffand students of the PMHUR and volunteers. In 1990, a comprehensive in situ map of the hull remains was completed and in accordance with the terms of an agreement between Malpas and Canton and the BMM, a team of archaeologists, students and volunteers raised the remains of the Western Ledge shipwreck in August 1991. Each recovered element of the wreck was transported to storage facilities at the museum and catalogued, cleaned, recorded and documented using techniques developed to record the Red Bay galleon. That work was completed in the autumn of 1991 and on 31st October 1991 the wreck structure was donated to the museum for study and possible display. 相似文献
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This review examines the history of discoveries that contributed to development of the dopamine hypothesis of schizophrenia. The origin of the hypothesis is traced to the recognition that neuroleptic drugs interfere with brain dopamine function. This insight was derived from two distinct lines of research. The first line originated from the discovery in 1956 that reserpine depletes brain serotonin. This finding resulted in a sequence of studies that led to the discovery that brain dopamine is involved in neuroleptic-induced extrapyramidal motor disturbances. The second line of research was aimed at determining the mechanism of action of psychomotor stimulants. This research produced evidence that stimulants directly or indirectly activate brain dopamine receptors. Because nonreserpine neuroleptics such as chlorpromazine block stimulant-induced movement, these findings suggested that neuroleptics were dopamine antagonists. Most previous accounts of the development of the dopamine hypothesis of schizophrenia emphasize the first line of research and ignore the second. 相似文献
59.
Recognition,Sovereignty Struggles,and Indigenous Rights in the United States: A Sourcebook. Edited by Amy E. Den Ouden and Jean M. O'Brien. (Chapel Hill,NC: University of North Carolina Press, 2013. Pp. 376. $26.95.)
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Tim Alan Garrison 《The Historian; a journal of history》2015,77(4):784-785
60.
This paper reveals the extent to which undergraduate students demonstrate transformative learning whilst on international fieldwork in Barcelona, Spain. Groups of students create a series of discrete active learning situations that allow them and their peers to engage more fully with their locale and in turn experience a deeper understanding of “place”. Reflective field trip notebooks are used to capture the experiences of students. Results show that through the use of the affective domain (Krathwohl’s taxonomy) and applying cyclic experiential learning (Kolb) combined with critical reflection (Mezirow), students demonstrate progression and, in some cases, regression along Krathwohl’s taxonomy. 相似文献