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111.
Fuchs RJ 《Population geography : a journal of the Association of Population Geographers of India》1981,3(1-2):41-56
Conflicts between explicit and implicit population distribution policies in Asian development plans are examined. Various implicit policies and their possible consequences for spatial distribution are discussed. The development plans of China and Thailand are analyzed with particular attention to population distribution goals, the principal explicit policies aimed at promoting those goals, and the implicit policies that might conflict with explicit goals. 相似文献
112.
沉积盆地形成的地球动力学机制及其分类 总被引:2,自引:0,他引:2
沉积盆地的形成主要与地球内部的热和物质的对流密切相关,它是沉积盆地形成和演化的原始动力。软流圈上涌高谋划在面或地幔羽的位置是地幔对 具体的表现。 相似文献
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Hypoxia and benthic community recovery in Korean coastal waters 总被引:1,自引:0,他引:1
Low dissolved oxygen (hypoxia and/or anoxia) has become a major cause of change to the benthic component of ecosystems around the world. We present the response of a benthic community to hypoxia in organically enriched environments in Korean coastal waters. Disturbances due to low dissolved oxygen (DO), and organic enrichment altered community dynamics, result in defaunation during summer hypoxia with delayed recolonization occurring in winter. As DO decreased, the number of taxa, their abundance and biomass of macrofauna dropped significantly at inner bay stations in Chinhae Bay and Youngsan River estuarine bay affected by hypoxia. With the return of normoxic conditions in Chinhae Bay, recolonization was initiated by opportunistic species, with a 1-4months lag. The polychaetes, Sigambra tentaculata, Mesochaetopterus sp., and Lumbrineris longifolia, were most persistent under hypoxia. The first recolonizers were the polychaetes Paraprionospio pinnata, S. tantaculata, Glycinde gurjanovae and Nectoneanthes multignatha and the bivalve Theora fragilis. The second group of colonizers included the polychaetes Capitella capitata, Mesochaetopterus sp. and L. longifolia, and the bivalve Raetellops pulchella. Hypoxic and near anoxic conditions resulted in mass mortality in Chinhae Bay and Youngsan River estuarine bay, but communities did partially recover after return to normoxic conditions despite delayed recolonization. 相似文献
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Lahaye V Bustamante P Law RJ Learmonth JA Santos MB Boon JP Rogan E Dabin W Addink MJ López A Zuur AF Pierce GJ Caurant F 《Marine environmental research》2007,64(3):247-266
Selected trace elements (Cd, Cu, Hg, Se, Zn) were measured in the kidneys and the liver of 104 harbour porpoises (Phocoena phocoena) stranded along the coasts of France, Galicia (Spain), Ireland, Scotland (UK), and the Netherlands. Generally, relatively low concentrations of toxic elements were encountered in the tissues of European porpoises, except for two individuals, which displayed high hepatic Hg concentrations. Also, elevated Cd levels obtained in Scottish porpoises could be related to their feeding preferences and this result suggests an increase of the proportion of cephalopods in their diet with latitude. Moreover, significant geographical differences were seen in hepatic Zn concentrations; the elevated Zn concentrations displayed by porpoises from the Netherlands may relate their poor health status. Variation in metal concentrations within porpoises from the North Sea is likely to reflect a long-term segregation between animals from northern (Scotland) and southern areas (the Netherlands), making trace elements powerful ecological tracers. 相似文献
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Although Soviet-era urban-growth controls produced relatively sustainable metropolitan development patterns, low-density suburban sprawl has accelerated markedly in modern Russia. Distinctive features of Moscow's development history are its greenbelt, which dates from 1935 and is becoming increasingly fragmented, proliferation of satellite cities at the urban fringe, conversion of seasonal dachas into full-time residences, the very exclusive Rublevo Uspenskoe Highway development, and today's crippling traffic congestion. The recent economic crisis has slowed development and actually increased the supply of “economy-class” single-family homes, for which there is much pent-up desire but insufficient credit availability to meet the demand. A renewed commitment to sustainability's triple bottom line—environmental quality, equity, and economic prosperity—will require greater government transparency and fairness, stronger planning controls, and an expanded public transportation system. 相似文献