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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
MacDonald RC Kimmerer TW Razzaghi M 《Environmental pollution (Barking, Essex : 1987)》1989,62(4):337-351
We measured the frequency with which leaves of trees in the Ohio River Valley produced ethanol aerobically, to determine if aerobic ethanol production might provide a viable field assay for air pollution stress. Leaves were collected from trees during the summers of 1985 and 1986 and ethanol production was determined using headspace GC. Frequency of ethanol production was compared with environmental factors, including air pollution concentrations. We found frequent foliar ethanol production and elevated alcohol dehydrogenase activity in the leaves of several species of trees in the Ohio River Valley, USA. The ethanol concentrations measured were often equivalent to those produced by anaerobic leaves. Ethanol production was associated with hot, hazy weather and elevated NO(2) concentrations. Ethanol production was more frequent in urban and industrialized areas. Ethanol production was not associated with natural stresses such as flooding and herbivory. We propose that aerobic ethanol production is the result of cell acidification due to the accumulation of acidic gases in the cytoplasm. The use of ethanol production as a diagnostic tool for detecting stress imposed by acidic gases is discussed. 相似文献
973.
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975.
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977.
The effects of predominant currents on the morphology of coral reefs has been studied in the leeward patch reefs of Anegada, British Virgin Islands. Measurements of current velocity and direction and sediment characteristics together with mapping of approximately 31 patch reefs within a 2 km2 area suggest that even under relatively low but constant current velocities (surface current 20 cm sec-1) the major reef-building corals show definite distribution patterns on the reef. The currents also appear to be responsible, in part, for marked orientation and elongation of patch reefs in a north-west/ south-east direction and for a gradation of patch-reef type across the study area. 相似文献
978.
979.
B. Fullerton Dr R. C. Wilkinson Jeremy Howells Naima Chabbis M. F. Downing 《Journal of Environmental Planning and Management》1986,29(2):98-100
URBANIZATION AND COMMUNITY BUILDING IN MODERN NORWAY
J. S. Tortenson, M. F. Metcalfe, T. F. Rasmussen
Urbana Press, Oslo 1985. 312 pp., figs and tables.
REGIONAL DEVELOPMENT POLICY
R. Riddell
Gower, 1985. £18.50
REVIEW OF SERVICE INDUSTRIES: A GEOGRAPHICAL APPRAISAL
P. W. Daniels
Methuen, 1985. £27.50.
ARABIC‐ISLAMIC CITIES: BUILDING AND PLANNING PRINCIPLES
Besim Selim Hakim
KPI Ltd., London, 1986. pp. 192. £46 (h/b)
FIFTY YEARS OF LANDSCAPE DESIGN
Sheila Harvey and Stephen Rettig
The Landscape Press, 1985. £12.50
CAPABILITY BROWN AND THE EIGHTEENTH CENTURY ENGLISH LANDSCAPE
Roger Turner
Weidenfeld & Nicholson. £16.95. 相似文献
980.