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951.
This paper surveys changes in the U.S. National Airway System since the 1960s. The most appropriate measures for summarizing air traffic distributions at airports are investigated, with the Gini Index of Concentration being used extensively to analyze U.S. airport traffic patterns over a twenty-four-year period. The properties of the Gini index and other measures are compared and discussed in detail in the context of analyzing air traffic distributions. It is shown how concentration in the traffic patterns at the larger airports was at a high level prior to deregulation, but since 1978, the patterns have gradually become even more concentrated.  相似文献   
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Radiocarbon Chronology of the Siberian Paleolithic   总被引:2,自引:0,他引:2  
We have compiled 462 C-14 determinations for 120 Paleolithic and Mesolithic sites from Siberia and the Russian Far East. The Mousterian sites are dated to ca. 46,000–28,500 BP. The Middle–Upper Paleolithic transition dates to ca. 43,300–28,500 BP. Although there are a few earlier sites, most of the Upper Paleolithic sites are dated to the time interval between ca. 34,000 BP and 10,000 BP. The earlier Upper Paleolithic stage is characterized by macroblade technology and is radiocarbon-dated to ca. 34,000–20,000 BP. The earliest microblade technology occurs in the late stage of the Upper Paleolithic, dated to ca. 23,000–20,000 BP, but the majority of microblade sites is dated to ca. 20,000–11,000 BP. The Final Paleolithic (Mesolithic) sites date to ca. 12,000–6000 BP. At ca. 13,000–11,000 BP, the earliest Neolithic appeared in both the Russian Far East (Amur River basin) and the Transbaikal. The Paleolithic–Neolithic transition occurred ca. 13,000–6000 BP.  相似文献   
957.
Recent fieldwork has considerably increased our knowledge of early Holocene settlement in Southwest Arabia. Neolithic settlement occurred within an environmental context of increased monsoonal moisture that continued during the mid-Holocene. A now well-attested Bronze Age exemplified by village- and town-scale settlements occupied by sedentary farmers developed toward the end of the mid-Holocene moist interval. The high plateau of Yemen was an early focus for the development of Bronze Age complex society, the economy of which relied upon terraced rain-fed and runoff agriculture. On the fringes of the Arabian desert, the precursors of the Sabaean literate civilization have been traced back to between 3600 and 2800 B.P., and even earlier, so that a virtually continuous archaeological record can now be described for parts of Yemen. In contrast to the highlands these societies relied upon food production from large-scale irrigation systems dependent upon capricious wadi floods. Bronze Age settlement, while showing some links with the southern Levant, now shows equal or stronger linkages with the Horn of Africa across the Red Sea. Although some regions of Yemen show breaks in occupation, others show continuity into the Sabaean period when a series of major towns grew up in response to the incense trade with the north. It is now clear that these civilizations grew up on the foundations of earlier Bronze Age complex societies.  相似文献   
958.
I summarize recent archaeological work in Oaxaca, Mexico, with a focus on questions central to world prehistory: the origin and collapse of complex societies. Monte Albán was the capital of an emerging civilization in the southern highlands of Mexico during the second half of the first millennium B.C. Soon after the foundation of the ancient city, there is evidence for state formation and a political expansion into regions outside the Valley of Oaxaca. Centuries later, Monte Albán went into decline, giving way to the competing small polities found throughout Oaxaca at the time of the Spanish conquest. Since the late 1960s, our knowledge of these changes has been transformed by study of Oaxaca's pre–Monte Albán past, regional settlement surveys, and processual model building. Evolutionary and historical perspectives allow for significant refinement of current debates surrounding the rise and fall of complex societies in Oaxaca.  相似文献   
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The Early Historic Period in the Mun Valley occupies a critical three centuries, from A.D. 500 to A.D. 800, a period often known as that of Zhenla, a name derived from early Chinese accounts. This article first describes early findings of fieldwork designed to illuminate the prehistory of the upper Mun Valley, a period which covers approximately two millennia, with initial settlement now dated between 1500 and 1000 B.C. It then considers the nature of the transition to the complex polities of Zhenla. This involves a combination of archaeological and documentary evidence. Sources for the latter are rare for the Mun Valley, but by broadening the area considered, it is possible to integrate archaeological and historical sources in order to portray the intensifying social changes which characterize the Early Historic Period. It is suggested that most of the Mun Valley was occupied by Khmer speakers during the Iron Age, people responsible for the transition to increasingly centralized polities of the Early Historic Period. In the upper reaches of the Mun catchment, and in the Chi Valley to the north, the late prehistoric inhabitants spoke Mon. They had close affinities with the Dvaravati polities of Central Thailand. If confirmed, this hypothesis would indicate a series of local trends towards increasing social complexity which we can recognize in the early epigraphic record.  相似文献   
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