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61.
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Since the 20th century, numerous Quaternary moraine dating methods have emerged, including lichenometric, moraine 14C, quartz sand thermoluminescence (TL), electron spin resonance (ESR), optically stimulated luminescence (OSL) and 10Be, 26A1, 36C1, 3H, 21Ne nuclide dating methods. These dating methods are widely applied to determine moraine ages and have provided a large dataset. Unfortunately each method has its defects. In this paper, we will review these various dating methods and provide some comments. 相似文献
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鲁北平原因超量开采地下水而引发了诸多水环境问题.本文对其分布规律和演化趋势进行了分析,并提出了对策建议. 相似文献
66.
Throughout the world, the coastal zones of many countries are used increasingly for aquaculture in addition to other activities
such as waste disposal. These activities can cause environmental problems and health problems where they overlap. The interaction
between aquaculture and waste disposal, and their relationship with eutrophication are the subjects of this paper.
Sewage discharge without adequate dispersion can lead to nutrient elevation and hence eutrophication which has clearly negative
effects on aquaculture with the potential for toxic blooms. Blooms may be either toxic or anoxia-causing through the decay
process or simply clog the gills of filter-feeding animals in some cases. With the development of aquaculture, especially
intensive aquaculture, many environmental problems appeared, and have resulted in eutrophication in some areas. Eutrophication
may destroy the health of whole ecosystem which is important for sustainable aquaculture.
Sewage discharge may also cause serious public health problems. Filter-feeding shellfish growing in sewage-polluted waters
accumulate micro-organims, including human pathogenic bacteria and viruses, and heavy metal ion, presenting a significant
health risk. Some farmed animals may also accumulate heavy metals from sewage. Bivalves growing in areas affected by toxic
algae blooms may accumulate toxins (such as PSP, DSP) which can be harmful to human beings. 相似文献
67.
WANGHong GUChao-lin 《中国地理科学(英文版)》2002,12(2):152-156
Chinaˊs urban reforms have brought social progress and development,but a comprehensive national system of social welfare(for example,unemployment insurance,pensions,medical care and public housing)for new migrants from rural areas is lacking.One of the most remarkable changes in Chinese cities in the last decade was a change in so-cial“equality“,with the rise of new poverty both in individual communities and some social groups in urban society.Howev-er,there is little social assistance and public infrastructure for the migrants.Governments or communities or individual should pay attention to the control of new urban poverty and new slums.This paper consider that it is necessary to launch a successful policy,which include mainly:1)accommodating urban growth through low-cost investment projects;2)ur-ban economy depends heavily on successful macroeconomic policy;3)to broaden the three channels linking adjustment to the incidence of urban poverty;4)to restructure urban economic based on the high or new technology;5)to coordi-nate relationship between urban economic growth and environment management for sustainable development of Beijingˊs metropolitan fringe. 相似文献
68.
David L. Mary 《Journal of Astrophysics and Astronomy》2005,26(2-3):283-292
We provide a detailed introduction to the main problems arising when analyzing light curves in asteroseismology. Attention
is first paid to the signal model delivered by the pulsating stars and to the noise sources corrupting this model in photometric
observations. The main pitfalls and ambiguities occurring in Fourier analysis are summarized and illustrated. Some classical,
Least Squares (LS) based methods for spectrum analysis are analyzed and commented on from the point of view of ill-posed problems.
The insight that can be gained from such analyses is discussed. 相似文献
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《The Professional geographer》1982,34(3):352-379
Books reviewed in this article: Aerial Photography and Remote Sensing Aerial photography and image interpretation for Resource Management . DAVID P. PAINE . Analytical Models and Techniques Spatial Processes Models and Applications A. D. CLIFF AND J. K. ORD Quantitative and Statistical Approaches to Geography: A Practical Manual JOHN A. MATTHEWS . Cartography and Maps Map Data Processing . HERBERT FREEMAN AND GOFFREDO G. PIERONI , eds. Computer-assisted Cartography: Principles and Prospects, 1982 . MARK S. MONMONIER . Cultural Navajo Architecture: Forms, History, Distributions . STEPHEN C. JETT AND VIRGINIA E . SPENCER . Rational Landscapes and Humanistic Geography . EDWARD RELPH . Economic The Structure and Control of a State Economy . W. L. L'ESPERANCE . Economic Geography . JAMES O. WHEELER AND PETER O. MULLER . The Myth of the Family Farm: Agribusiness Dominance of U.S. Agriculture . INGOLF VOCELER . Libya: The Experience of Oil . J. A. ALLEN . Geography of Public Finance, Welfare Under Fiscal Federalism and local Government Finance . ROBERT BENNETT . Environmental Management, Resources, and Systems Mountains and Man . LARRY W. PRICE . Environmental Geology . DONALD R. COATES . An Introduction to Environmental Systems . G. H. DURY . The Environment: Chinese and American Views . Edited by LAURENCE J. C. MA AND ALLEN G. NOBLE . Land Use in America . RICHARD H. JACKSON . Medical Conceptual and Methodological Issues in Medical Geography . MELINDA S. MEADE (ed.). Philosophy and Geographic Thought Birds in Egg/Eggs in Bird . GUNNAR OLSSON . PhysicaI Climatology: Selected Applications . J. E. OLIVER . Geomorphological Techniques . ANDREW GOUDIE (ed.). Political Politics, Geography and Behaviour . RICHARD MUIR AND RONAN PADDISON . The State of the World Atlas . MICHAEL KIDRON AND RONALD SECAL . Population The Population of the South . DUDLEY L. POSTON , JR . AND ROBERT H. WELLER , eds. Regional Latin America: Economic Development and Regional Differentiation . ARTHUR MORRIS . Developing the Amazon . EMILIO F. MORAN . Western Europe: A Systematic Human Geography . BRIAN W. ILBERY . Settlement Systems in Sparsely Settled Regions: The United States and Australia . RICHARD E. LONSDALEAND JOHN H. HOLMES , eds. African Perspectives: The Economic Geography of Nine African States . HARM DE BUJ AND ESMOND MARTIN , eds. Rural Nonmetropolitan America in Transition . AMOS H. HAWLEY AND SARA MILLS MAZIE , eds. Social Crime and Environment . R. NORMAN DAVIDSON . The Ghetto: Readings with Interpretations . JOE T. DARDEN , ed. Urban Urban Problems and Planning in the Developed World . MICHAEL PACIONE (ed.) Problems and Planning in Third World Cities . Edited by MICHAEL PACIONE . The City in West Europe . D. BURTENSHAW , M. BATEMAN , AND C. J. ASHWORTH . 相似文献