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Troy Sternberg Nicholas Middleton David Thomas 《Transactions (Institute of British Geographers : 1965)》2009,34(3):364-377
The desert-steppe region of southern Mongolia is susceptible to drought and extreme winter weather ( dzud ) that in combination form Mongolia's worst natural hazard. Low precipitation and high climatic variability in this dryland environment impact the landscape and affect pastoralism, the dominant rural lifestyle. Using the Standardised Precipitation Index (SPI), this paper identifies drought occurrence in South Gobi Province, Mongolia. It then examines the relationship of drought with climate factors, interaction with vegetation (derived from Normalised Difference Vegetation Index - NDVI - data), and local human and livestock populations, and the dzuds of 1999–2001. Results show that drought is recurrent in the region, reaching extreme intensity most recently in 2005–2006. In contrast with the prevailing concept of drought impacting dzuds , the study did not find a connection between drought and dzud in South Gobi Province. Though repeated events, these natural hazards occur independently in the region. Climatic variables show increasing temperatures (>1°C), fluctuating precipitation patterns and a decline in vegetation cover. The principal long-term correlation of drought is with human population rather than natural factors, dzud or livestock numbers. 相似文献
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The initial interpretations of motion phenomena are often in terms of eye movements. It reflects a desire to link an objective expression of motion (of the eyes) with a subjective experience of motion. This approach is examined historically with respect to induced motion, motion aftereffects, visual vertigo, autokinetic effects and stroboscopic motion. All but one of these phenomena were initially observed in the natural environment and they have subsequently been studied under laboratory conditions. Eye movements are not correlated with induced motion, the motion aftereffect, or stroboscopic motion, but they do correspond to the direction and extent of visual vertigo. The extent of apparent visual motion in the autokinetic effect far exceeds that of involuntary eye movements but there might be a weak relation between them. If eye movements are to provide a reasonable account of motion illusions then they should apply to all the contours that are visible. This does apply to visual vertigo, but not to induced motion, the motion aftereffect and stroboscopic motion, all of which involve relative motion in a visible display. The autokinetic phenomenon involves the perception of isolated stimuli, and so interpretations in terms of some internal eye movement signals remain sustainable. 相似文献
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Archaeological evidence of ceramic production most commonly consists of locally procured raw materials. Excavations at Tell el-Timai in Lower Egypt recovered raw fine marl clay from two transport jars in the vicinity of pottery kilns dating to the 4th century b.c. Production wasters of small perfume bottles produced in the same fine marl clay were found inside the kilns. The marl clay inside the jars pointed to an origin outside of Lower Egypt. Samples of the clay and wasters, along with a confirmed locally sourced sample, were subjected to X-Ray Fluourescence (XRF) analysis, revealing significant differences in their chemical compositions. The results of the analysis are compared to published Egyptian data and an Upper Egyptian provenience is suggested because the raw clay is consistent with available comparative XRF data. 相似文献
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The Material Culture of Daily Living in the Anglo‐Saxon World. Ed. by Maren Clegg Hyer and Gale R. Owen‐Crocker. Exeter Studies in Medieval Europe. Exeter: University of Exeter Press. 2011. 386 pp., 70 illus., b/w and line drawings. £60. ISBN 978 0 85989 843 0. 下载免费PDF全文
Nicholas A. Sparks 《Early Medieval Europe》2016,24(2):243-244
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Alexander Nicholas Shaw 《Cold War History》2017,17(3):279-297
This article evaluates the influence of the Azerbaijan crisis of 1945–46 on evolving perceptions of the Soviet Union within the British Foreign Office. Utilising records from the National Archives and personal papers, it synthesises the history of the Azerbaijan crisis with studies of Britain’s changing Soviet policy, previously focused solely on the Northern Department and Moscow representative Frank Roberts. In so doing, the paper provides an original diplomatic history which argues that, although Europe remained the strategic priority for Foreign Secretary Ernest Bevin, Iranian developments were of greater significance in prompting a perceptual transition from cooperation to Cold War confrontation. 相似文献