Evolution of sedimentary basins — the integrated modeling approach     

H. S. Poelchau  U. Mann 《International Journal of Earth Sciences》1989,78(1):1-5

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Editor''s note     

C. John Mann 《Mathematical Geology》1989,21(8):959-960

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Book review     

C. John Mann 《Mathematical Geosciences》1994,26(3):413-414

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Editor''s note     

C. John Mann 《Mathematical Geology》1990,22(2):149

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The Little Ice Age : By Jean Grove. Methuen Publishers, London/New York, 498 pp     

Daniel H. Mann 《Quaternary Research》1990,34(3)

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Editor's note     

C. John Mann 《Mathematical Geosciences》1985,17(8):853-853

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Algal uptake of U and some other metals: Implications for global geochemical cycling     

H. Mann  W.S. Fyfe 《Precambrian Research》1985,30(4):337-349

Freshwater green algae Ankistrodesmus sp, cultured in dilute solutions of metals chelated with EDTA, revealed massive uptake of U. Examination of Thames River waters and selected micro-organisms of its aquatic ecosystem revealed an average dissolved U concentration of 1.46 ppb, representing about twice the global mean riverine solute concentration of 0.6 ppb U. Suspended particulates, principally algae, contain U at 10³ to 10⁵ times that of their river habitat, averaging 28 300 ppb U. One community of the filamentous algae Spirogyra sp. contained intracellular crystals tentatively identified as the Ca-oxylate weddelite. Studies of algae from a variety of environments have shown large concentration factors for a wide range of elements. Algae from an acid U mine tailings site contain up to 2.7% U (dry weight) plus very high concentrations of other metals. Micro-organisms may act as an important sink for metal solutes in the hydrosphere.  相似文献   

Monitoring and Verifying Changes of Organic Carbon in Soil   总被引：19，自引：0，他引：19  

W. M. Post  R. C. Izaurralde  L. K. Mann  N. Bliss 《Climatic change》2001,51(1):73-99

Changes in soil and vegetation management can impact strongly on the rates of carbon (C) accumulation and loss in soil, even over short periods of time. Detecting the effects of such changes in accumulation and loss rates on the amount of C stored in soil presents many challenges. Consideration of the temporal and spatial heterogeneity of soil properties, general environmental conditions, and management history is essential when designing methods for monitoring and projecting changes in soil C stocks. Several approaches and tools will be required to develop reliable estimates of changes in soil C at scales ranging from the individual experimental plot to whole regional and national inventories. In this paper we present an overview of soil properties and processes that must be considered. We classify the methods for determining soil C changes as direct or indirect. Direct methods include field and laboratory measurements of total C, various physical and chemical fractions, and C isotopes. A promising direct method is eddy covariance measurement of CO₂ fluxes. Indirect methods include simple and stratified accounting, use of environmental and topographic relationships, and modeling approaches. We present a conceptual plan for monitoring soil C changes at regional scales that can be readily implemented. Finally, we anticipate significant improvements in soil C monitoring with the advent of instruments capable of direct and precise measurements in the field as well as methods for interpreting and extrapolating spatial and temporal information.  相似文献   

Jorvik MIST – 2001     

Neil Arnold  Ian Mann 《Astronomy& Geophysics》2001,42(4):4.18-4.20

The magnetosphere, ionosphere and solar–terrestrial physics community gathered at the Department of Chemistry, University of York from 9–11 April 2001. Neil Arnold and Ian Mann report.  相似文献   

Observations on the biota of an estuarine beach at Hardys Bay (NSW, Australia) following a spillage of aldrin     

P.R. Scanes  R.A. Mann  T.M. Manning  J.C. Chapman 《Marine pollution bulletin》1993,26(12):687-691

An industrial accident resulted in a spillage of aldrin onto an estuarine beach at Hardys Bay, New South Wales. Samples of water and sediment were taken 3 weeks later to measure the level of contamination resulting from the spill. The abundances of some intertidal biota were also determined at the site of the spillage and in other uncontaminated areas.

Three weeks after the spill, samples of water were not contaminated by aldrin but samples of sediment from the surface in the vicinity of the drain contained aldrin. In comparison to uncontaminated locations the abundances of crustacea were greatly reduced in the vicinity of the drain but abundances of polychaetes were not significantly different. The field data on the relative susceptibility of the two groups of animals agrees well with laboratory derived LC50 data for crustacea and polychaetes.

The study suggests that degree of contamination of water and sediment may not always be an accurate reflection of acute impact on biota, and that different components of the biota can show different reactions to the presence of a toxic chemical.  相似文献