993 resultados para Architecture, Ancient.


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The Qinghai-Tibet Plateau is characterized by extremely high radiation, which may induce down-regulation of photosynthesis in plants living in this alpine ecosystem. To clarify whether photoinhibition occurs in the alpine environment and to discern its underlying mechanisms, we examined photosynthetic gas exchange and fluorescence emission in response to the changes in photosynthetic photon flux density (PPFD) and leaf temperature under natural regimes for two herbaceous species: prostrate Saussurea superba and erect-leaved Saussurea katochaete from altitude 3250 m on the Qinghai-Tibet Plateau. S. superba intercepted a higher maximum PPFD and experienced much higher leaf temperature than the erect-leaved S. katochaete. S. superba exhibited a much higher light saturation point for photosynthesis than S. katochaete. Under controlled conditions, the former species had higher CO2 uptake rates and neither species showed obvious photosynthetic down-regulation at high PPFD. Under natural environmental conditions, however, apparent photoinhibition, indicated by reduced electron transport rate (ETR), was evident at high PPFD for both species. After a night frost, the photochemistry of S. katochaete was depressed markedly in the early morning and recovered by mid-day. After a frost-free night, it was high in the morning and low at noon due to high radiation. S. superba did not respond to the night frost in terms of daytime photochemical pattern. In both species, photochemical depression was aggravated by high leaf temperature and the erect species was more sensitive to high temperature. This study suggests that the high radiation on the Qinghai-Tibet Plateau is likely to induce rapidly reversible photoinhibition, which is related closely to plant architecture. Photochemistry in the prostrate species seems able to tolerate higher PPFD, without obvious suppression, than the erect species. (C) 2003 Elsevier Science B.V. All rights reserved.

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Jiamusi Massif is an important tectonic unit in Northeast China. It’s significant for understanding the evolution of Paleo-Asian Ocean and reconstruction of the tectonic framework of Northeast China. Mudanjiang area is located in the southern margin of Jiamusi Massif and is the key to understand the evolution of Jiamusi Massif. However, the detailed geological research for Mudanjiang area has long been deficient in many important problems, such as the tectonic components of the Mudanjiang collision zone (MCZ), the age of collisional complexes and the scenario of tectonic evolution. Based on the lithology, geochemistry and the SHRIMP zircon U-Pb geochronology in Mudanjiang area, our new data and results come to some constraints for the tectonic reconstruction of MCZ as follows: 1) It is identified that the former suggestion, which the so-called “Heilongjiang Group” in Mudanjiang area is the vestige of oceanic crust, is correct. The oceanic relics represent the Neo-Proterozoic-Early Paleozoic oceanic basins based on the SHRIMP zircon U-Pb geochronology. 2) One sheet of gabbroic complex with oceanic island-type geochemical signature was discovered by this work in Mudanjiang area. 3) It is verified that the Proterozoic concordant U-Pb ages of the migmatites developed along the southern margin of Jiamusi massif, which represent the events of magmatic intrusion, as the direct evidence for the existence of the Proterozoic crystalline basements of the Jiamusi Massif. Based on geochronology, we suggest that the migmatization and coeval S-type granite magmatism of the southern margin of Jiamusi Massif took place about 490Ma. 4) The island arc complex has been found in the Heilongjiang Group, and the oceanic relics was found distributing on both sides, as provided important constraint for the tectonic reconstruction of the MCZ. 5) ~440Ma metamorphic event and coeval post-collisional granite magmatism have been firmly identified in the MCZ and its southern neighboring area. Together with previous data obtained by other researchers, our conclusions on the reconstruction of the tectonic architecture and evolution of the MCZ as follows: 1) The orogenic assemblages developed in the Mudanjiang collisional zone are featured by a sequence of ancient active continental margins and ensuing orogenic processing. The Mashan Group is the reworking basement of Jiamusi Massif, whereas the Heilongjiang Group represents arc and oceanic complexes characterized by imbricate deep-seated sliced and slivering sheets due to multi-phases of thrusting and nappe stacking. 2) The northern sub-belt of MCZ is probably the arc-continent collisional boundary related to the closure of main oceanic basin. The collisional age can be constrained by the events of syn-orogenic migmatization of migmatite, coeval S-type granite magmatism and the related granulite-facies metamorphism. Therefore, we suggested the collisional age of northern sub-belt is probably Cambrian-Early Ordovician. The extensive granulite-facies metamorphism of the Mashan Group in Jiamusi Massif, as affirmed by former works, was probably related with the collisional event. 3) The southern sub-belt of the MCZ was possibly related with the closure of back-arc basin. We presumed that the collisional age of southern sub-belt is about Ordovician-Early Silurian according to the ~440Ma extensive metamorphism and the occurrence of coeval post-collisional granite magmatism. 4) The extant structural architecture of the MCZ is related to the multi-phases of intra-continental superimposition, which is characterized by the Mesozoic nappe structure.

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The Message-Driven Processor is a node of a large-scale multiprocessor being developed by the Concurrent VLSI Architecture Group. It is intended to support fine-grained, message passing, parallel computation. It contains several novel architectural features, such as a low-latency network interface, extensive type-checking hardware, and on-chip memory that can be used as an associative lookup table. This document is a programmer's guide to the MDP. It describes the processor's register architecture, instruction set, and the data types supported by the processor. It also details the MDP's message sending and exception handling facilities.

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This paper consists of two major parts. First, we present the outline of a simple approach to very-low bandwidth video-conferencing system relying on an example-based hierarchical image compression scheme. In particular, we discuss the use of example images as a model, the number of required examples, faces as a class of semi-rigid objects, a hierarchical model based on decomposition into different time-scales, and the decomposition of face images into patches of interest. In the second part, we present several algorithms for image processing and animation as well as experimental evaluations. Among the original contributions of this paper is an automatic algorithm for pose estimation and normalization. We also review and compare different algorithms for finding the nearest neighbors in a database for a new input as well as a generalized algorithm for blending patches of interest in order to synthesize new images. Finally, we outline the possible integration of several algorithms to illustrate a simple model-based video-conference system.

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New Timber Architecture in Scotland illustrates 90 exemplar projects and demonstrates clearly that there is no single building type unsuited to the use of this adaptable, variable and infinitely renewable material. Too long out of fashion, timber is now widely specified and has become an important design element in some of the most innovative projects being built today. The projects selected for inclusion are not the work of a few superstar architects: they represent the output of a significant percentage of architectural practices in Scotland and illustrate a burgeoning confidence in timber as an exciting, contemporary construction material. New Timber Architecture in Scotland aims to stimulate others to follow their lead.

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Grattan, J.P., Al-Saad, Z., Gilbertson, D.D., Karaki, L.O., Pyatt, F.B 2005 Analyses of patterns of copper and lead mineralisation in human skeletons excavated from an ancient mining and smelting centre in the Jordanian desert Mineralogical Magazine. 69(5) 653-666.

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Pyatt, F.B., Pyatt, A.J., Walker, C., Sheen, T., Grattan, J.P, The heavy metal content of skeletons from an ancient metalliferous polluted area in southern Jordan with particular reerence to bioaccumulation and human health, Ecotoxicology & Environmental Safety 60, 13th August 2003, 295-300

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Pyatt, B. Amos, D. Grattan, J. Pyatt, A. Terrell-Nield, C. Invertebrates of ancient heavy metal spoil and smelting tip sites in southern Jordan: Thier distribution and use as bioindicators of metalliferous pollution derived from ancient sources. Journal of Arid Environments. 2002. 52 pp 53-62

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Pyatt, B. Gilmore, G. Grattan, J. Hunt, C. McLaren, S. An imperial legacy? An exploration of the environmental impact of ancient metal mining and smelting in southern Jordan. Journal of Archaeological Science. 2000. 27 pp 771-778

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Grattan, J., Huxley, S., Karaki, L. A., Toland, H., Gilbertson, D., Pyatt, B., Saad, Z. A. (2002). 'Death . . . more desirable than life'? The human skeletal record and toxicological implications of ancient copper mining and smelting in Wadi Faynan, southwestern Jordan. Toxicology and Industrial Health, 18 (6), 297-307.

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IEEE Transactions on Knowledge and Data Engineering, vol. 15, no. 5, pp. 1338-1343, 2003.

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Sims-Williams, P. (2006). Ancient Celtic Place-Names in Europe and Asia Minor: Publications of the Philological Society, 39. Oxford: Blackwell Publishing. RAE2008

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How rainfall infiltration rate and soil hydrological characteristics develop over time under forests of different ages in temperate regions is poorly understood. In this study, infiltration rate and soil hydrological characteristics were investigated under forests of different ages and under grassland. Soil hydraulic characteristics were measured at different scales under a 250 year old grazed grassland (GL), a six (6 yr) and 48 (48 yr) year old Scots pine (Pinus sylvestris) plantation, remnant 300 year old individual Scots pines (OT) and a 4000 year old Caledonian Forest (AF). In-situ field saturated hydraulic conductivity (Kfs) was measured and visible root:soil area was estimated from soil pits. Macroporosity, pore structure, and macropore connectivity were estimated from X-ray tomography of soil cores, and from water-release characteristics. At all scales the median values for Kfs, root fraction, macro-porosity and connectivity values tended to AF > OT > 48 yr > GL > 6 yr, indicating that infiltration rates and water storage increased with forest age. The remnant Caledonian Forest had a huge range of Kfs (12 to > 4922 mm h-1), with maximum Kfs values 7 to 15 times larger than 48-year-old Scots pine plantation, suggesting that undisturbed old forests, with high rainfall and minimal evapotranspiration in winter, may act as important areas for water storage and sinks for storm rainfall to infiltrate and transport to deeper soil layers via preferential flow. The importance of the development of soil hydrological characteristics under different aged forests is discussed.