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301.
率先在国土资源领域培育并形成相对稳定的元素化学形态(价态、金属有机化合物等)分析及其生态环境地球化学应用研究团队,采用高效液相色谱-电感耦合等离子体质谱联用技术,开展生态环境地球化学样品中痕量溴、碘、砷、镉、汞、锡、铅、铬、硒等有益有害元素的价态、金属有机化合物等形态分析方法研究,初步建立了有益有害元素形态分析体系。建立的形态分析方法灵敏度高、检出限低,具有创新性和实用性,工作成果在国内外期刊发表论文20篇。形态分析方法在我国环境地球化学研究中得到应用并取得了良好的应用成果,从形态分析水平上表征元素的环境地球化学及其健康效应在国内外属于探索性工作。  相似文献   
302.

Book Reviewed in this article:

Latin America: Case Studies. Richard G. Boehm and Sent Visser

Locality and Rurality: Economy and Society in Rural Regions. Tony Bradley And Philip Lowe

The City and the Grassroots. Manuel Castells

Geopolitics and Conflict in South America. Quarrels among Neighbors. Jack Child

Post-Industrial America: A Geographical Perspective. David Clark

Coastal Research: UK Perspectives. Malcolm W. Clark

A Rural Policy for the EEC? Hugh Clout

Peasant Agriculture in Assam: A Structural Analysis. M. M. Das.

Environmental Change and Tropical Geomorphology. I. Douglas and T. Spencer

Advances in Abandoned Settlement Analysis: Application to Prehistoric Anthrosols in Colombia, South America. Robert C. Eidt

Measuring Culture. Jonathan L. Gross and Steve Rayner

North America: A Human Geography. Paul Guinness and Michael Bradshaw

A Geographical Bibliography for American Libraries. Chauncy D. Harris et al.

Geography and the Urban Environment: Progress in Research and Applications, Vol. VI. D. T. Herbert and R. J. Johnston

Changes in Global Climate: A Study of the Effect of Radiation and Other Factors During the Present Century. K. Ya. Kondrat'ev.

Rural Development and the State: Contradictions and Dilemmas in Developing Countries. David A. M. Lea and D. P. Chaudhri

The Martial Metropolis: U.S. Cities in War and Peace. Roger W. Lotchin

The Climate of the Earth. Paul E. Lydolph.

Weather and Climate. Paul E. Lydolph.

Spatial Divisions of Labor: Social Structures and the Geography of Production. Doreen Massey.

Panorama of the Soviet Union. N. Mikhailov.

Soviet Armenia. K. S. Demirchian.

USSR: Geography of the Eleventh Five-Year Plan Period. K. Spidchenko.

Planung und Verwirklichung der Wiener Ringstrassenzone (Planning and Materialization of the Ringstrasse-Zone of Vienna). Kurt Mollik, Hermann Reining, Rudolf Wurzer.

The American West Transformed: The Impact of the Second World War Gerald D. Nash.

An Overview of the Survey of Income and Program Participation. Dawn Nelson, David McMillen, and Daniel Kasprzyk.

Phenomenology, Science and Geography: Spatiality and the Human Sciences. John Pickles.

Biological Diversification in the Tropics. Ghillean T. Prance

Die Wanderviehwirtschaft im gebirgigen Westen der U.S.A. und ihre Auswirkungen im Naturraum. Gisbert Rinschede.

Social and Economic Aspects of Radioactive Waste Disposal: Considerations for Institutional Management

World-Wide Weather. K. Takahashi

Coastal Geomorphology in Australia. B. G. Thom

Settlement System in Rural India: A Case Study of the Lower Ganga-Yamuna Doab. Ram Chandra Tiwari.

Computer Programming for Geographers. David J. Unwin and John A. Dawson.

Late Quaternary Environments of the Soviet Union. A. A. Velichko, ed. H. E. Wright, Jr. and C. W. Barnosky

Ethics in Planning. Martin Wachs  相似文献   
303.
Geologic and geochemical variations across a 4200 km2 area of south-central Wisconsin (USA) were used to examine their relationship to phosphorus concentrations in groundwater from more than four hundred private water supply wells. Surficial geology in the study area ranged from Cambrian sandstones to Ordovician dolomites. Groundwater phosphorus concentrations were higher in aquifers of older Cambrian age compared to the concentrations in aquifers of younger Cambrian and Ordovician age. Because iron concentrations were relatively low in these waters and agricultural land use was similar in all geologic regions, we propose that the differences in bedrock phosphorus and anthropogenic geochemical impacts explain the differences in phosphorus concentrations between aquifers. Within the older Cambrian aquifers, groundwater phosphorus concentrations were elevated in groundwater with higher nitrate-nitrogen concentrations. This finding is consistent with the presence of phosphorus within sediment in these strata and geologic conditions that weakly buffered pH reduction from anthropogenic acidification. In contrast, groundwater phosphorus concentrations in younger Cambrian and Ordovician aquifers were not elevated in samples with higher nitrate. Anthropogenic acidification in these carbonate-rich aquifers was neutralized through increased carbonate weathering, which led to higher groundwater calcium and alkalinity and would limit the dissolution of phosphate-rich minerals, such as apatite, where present. Low iron concentrations observed in most samples suggest that the phosphorus release in the Cambrian strata occurs beyond the zone of secondary mineral retention in the soil. These results have important implications for the eutrophication of inland surface waters in areas with bedrock phosphorus and anthropogenic acidity that is not neutralized before it contacts phosphatic rock.  相似文献   
304.
黄、东海海域溶解无解机砷分布特征与化学形态   总被引:2,自引:1,他引:1  
Distribution and chemical speciation of dissolved inorganic arsenic were examined in Yellow Sea and East China Sea. Results demonstrated that: (1) both As(III) and As(V) were detected, with As(V) domin...  相似文献   
305.
Dissolved cadmium and copper species were measured in the Loire estuary and the North Biscay Bay continental shelf (France) in spring 2002. Metal behaviours along the salinity gradient, metal fluxes from the Loire system and surface distributions on the continental shelf were described and compared with the ones obtained at a period of higher discharge (i.e., winter 2001). Vertical distributions at different stations were also examined with the aim to assess whether the Loire inputs affect the Cu and Cd speciation over the continental shelf. In the Loire estuary, different metal behaviours were observed from winter. Cu and its various species mostly followed a theoretical dilution line whereas a Cd addition composed of chloro- and organic complexes was observed. According to our estimations, the Cu flux was composed, as in winter, of 40% hydrophobic organic complexes. On the other hand, Cd organic complexes accounted for less in the total dissolved metal flux than they did in winter (55 and 78% for spring and winter, respectively). On the continental shelf, a C18Cu-to-TDCu ratio of 40% was observed in the stratified area under Loire influence. For Cd, the organic fraction was relatively important in the surface waters near the mouth of the estuary and decreased deeper and seaward. Thus, the Cu and Cd speciation on the North Biscay Bay continental shelf are firstly determined by the extent of the estuarine plume. Beyond the estuarine influence, biological processes appeared to be the origin of the observed variations.  相似文献   
306.
The concentrations of total selenium (Se) and Se (IV) were determined in the surface waters of 30 stations located in the James River and southern Chesapeake Bay. The concentrations of total Se and Se (IV) ranged from 0·28 to 1·91 nM and from 0·07 to 1·36 nM, respectively, between salinities of 31·78 and 0·06‰. The concentration of Se (VI), calculated as the difference between the concentrations of total Se and Se (IV), ranged from 0·08 to 0·67 nM. While total Se seemed to be conservative in this study area at salinities above 0·36‰, Se (IV) might have been removed during estuarine mixing. The removal of Se (IV) occurred primarily at salinities below 4‰ possibly via the oxidation of Se (IV) to Se (VI).  相似文献   
307.
The paper presents the results of determination of inorganic and organic forms of phosphorus in bottom sediments of Pomeranian Bay. The sediments were collected in March and July of 1996. The following characteristics of the sediments were determined: organic matter content, forms of inorganic phosphorus: loosely adsorbed phosphorus and phosphorus bound to aluminium, calcium and iron, as well as total inorganic phosphorus. Pomeranian Bay is a shallow basin, with depth averaging between 12 and 15 m and sandy sediments prevailing. Smaller silt fractions occur only in the vicinity of the wina River estuary and in deeper northern regions of the Bay. Calcium-bound phosphorus is the dominant form of inorganic phosphorus in the Pomeranian Bay. Iron-bound phosphorus is the second most prevailing form, and aluminium-bound phosphorus the third. Loosely bound phosphorus was present in the lowest amounts. Total inorganic phosphorus in the Bay consisted of the four forms listed above, except in estuarine regions where an additional form of phosphorus occurred, most probably occluded phosphorus. High organic phosphorus concentrations were found at the wina River estuary and in the northern part of the Bay (Saßnitz Deep) corresponding to the higher organic matter content of these sediments. Sediments of Pomeranian Bay contained less phosphorus than those from the Gulf of Gda sk or Puck Bay and other parts of the Baltic Sea, suggesting that the amount of phosphorus in the sediments was determined by a number of inter-related factors, such as sediment type, amount of organic matter, the chemical composition of the sediment and oxygen content of near-bottom water.  相似文献   
308.
309.
Abstract. Tethya microstella, T. orphei, T. robusta, and T. seychellensis live in sympatry in a Maldivian coral reef lagoon (Gangehi Island, Ari Atoll). A morphological, morphometric, and electrophoretical study of these species show that their Maldivian populations are well separated morphologically and genetically. The genetic distances and the other data are more consistent with an immigration than with a local speciation hypothesis. Their coexistence may be explained by a differentiation in ecological requirements. The four species inhabit the shallow water biotope of the lagoon among the rubble of dead corals. Our data show that T. orphei and T. seychellensis occupy the upper rubble layer, T. microstella and T. robusta the lower one. This distinction agrees with the different morpho-functional features of the two pairs of species.  相似文献   
310.
恩施渔塘坝富硒碳质岩石中硒的形态分析   总被引:2,自引:0,他引:2  
湖北恩施渔塘坝是中国人群硒中毒爆发性流行的地区,也是恩施较为典型的高硒地区之一。其北部出露的富硒碳质岩石,通常认为是渔塘坝硒的主要来源。采用7步连续化学浸提技术,将富硒碳质岩石中硒分为水溶态、可交换态、有机态、元素态、酸性提取态、硫化物/硒化物态和残渣态硒,使用氢化物-原子荧光法测定了岩石总硒和硒形态。结果表明,碳质页岩和碳质硅质岩中硒主要以有机态、硫化物/硒化物态和可交换态硒为主,碳质泥岩中硒以有机态、元素态和硫化物/硒化物态硒为主。碳质泥岩中的水溶态硒显著低于碳质页岩和碳质硅质岩中的水溶态硒,但元素态硒的比例显著高于后两者,说明碳质泥岩是富硒碳质岩层中硒易于富集的场所。富硒碳质岩中的可利用态硒主要以Se^4+为主,而非是Se^6+和有机硒。可交换态和有机结合态硒中Se^4+与岩石总硒的显著正相关关系表明,Se^4+离子的分布影响着岩石总硒,有机质与粘土在硒富集的地球化学过程中承担了重要作用。  相似文献   
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