Tributyltin inputs to the North Sea from shipping activities, and potential risk of biological effects     

Davies  Ian M.; Bailey  Susan K.; Harding  Melanie J.C. 《ICES Journal of Marine Science》1998,55(1):34-43

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Response of mesopheric ozone to particle precipitation     

Paul J. Crutzen  Susan Solomon 《Planetary and Space Science》1980,28(12):1147-1153

In the mesosphere, water vapor photolysis is the major source of odd hydrogen (H, OH and HO₂) under normal conditions. The odd hydrogen produced may then be converted to H₂ by the reaction H + HO₂→ H₂ + O₂. This process is responsible for the calculated decrease in the H₂O mixing ratio and accompanying increase in the H₂ mixing ratio with altitude in the upper mesosphere and lower thermosphere. Charged particle precipitation events are calculated to produce the same effect, particularly in the 70–85 km region, thus temporarily resulting in enhanced conversion of H₂O to H₂ following such an event. Since odd hydrogen is produced predominantly by water vapor photolysis at these altitudes, decreased odd hydrogen concentrations are also anticipated. Odd hydrogen processes dominate ozone destruction in this region, and so an increase in ozone may occur if odd hydrogen concentrations decrease. We have examined the calculated time behavior of these processes in a numerical model using the August 1972 solar proton event as an example, and we present calculations indicating what might be observed in future events.  相似文献   

On the population biology and meiofaunal characteristics of Manayunkia aestuarina (Polychaeta: Sabellidae: Fabricinae) from a South Carolina salt marsh     

Susan S. Bell 《Estuarine, Coastal and Shelf Science》1982,14(2):215-221

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MULTINATIONAL ENTERPRISES IN BRAZIL: LOCATIONAL PATTERNS AND IMPLICATIONS FOR REGIONAL DEVELOPMENT     

Susan M. Cunningham 《The Professional geographer》1981,33(1):48-62

The long-established role of foreign interests in Latin America, and specifically Brazil, has been perpetuated since 1945 by multinational corporations. This article analyzes five industries where foreign direct investment has been especially important. These industries tend toward spatial concentration, particulary in metropolitan locations and at growth poles offering special attractions. A comparative study of private Brazilian enterprises suggests that these may offer greater opportunities for regional development than do the MNC's but that such concerns are dependent to some extent upon both MNC's and governmental assistance for their growth.  相似文献   

Strategic planning and urban restructuring: the case of Pyrmont‐Ultimo     

Morgan Sant  Susan Jackson 《The Australian geographer》1991,22(2):136-146

The City West Urban Strategy is concerned with redevelopment in part of inner metropolitan Sydney. Such plans should not be seen in isolation, but in a wider temporal and spatial context. Pyrmont and Ultimo have been undergoing significant socioeconomic changes for a decade and this trend is likely to be reinforced and intensified if the Strategy is implemented. Also the recent and projected changes are consistent with a global pattern of restructuring in urban waterfront areas where former port and industrial functions have declined.  相似文献   

Oxygen consumption rates in pelagic sediments from the Central Pacific: First estimates from microelectrode profiles     

Clare E Reimers  Susan Kalhorn  Steven R Emerson  Kenneth H Nealson 《Geochimica et cosmochimica acta》1984,48(5):903-910

Oxygen profiles in pelagic sediments from the Manganese Nodule Program calcareous and siliceous ooze sites (MANOP sites C and S) in the central Pacific Ocean were measured with microelectrodes and are used to predict oxygen consumption rates beneath the sediment-water interface. We explain possible artifacts which occur during sample recovery and argue that minimum estimates of 0.083 and 0.025 μ moles $\text{O}{}_2\text{cm}{}^2\text{day}$ (C and S, respectively) can be calculated from the data. These oxygen consumption rates are in good agreement with in situ respirometer measurements previously reported for comparable sediments in the north Pacific, but previous estimates based on modeling of pore water nitrate profiles at both sites are two to five times smaller than our minimum fluxes. The differences in oxygen fluxes calculated by the two methods are probably in part due to uncertainty in the assumptions inherent in the nitrate model. However, non-steady state fluctuations in particulate organic matter fluxes could also be a reason for the disparity.  相似文献   

Symposium über Fragen der Cyanophytentaxonomie im Seenforschungsinstitut der ETHZ/EAWAG in Kastanienbaum (Schweiz), 2.–15. August 1979 Verhandlungsbericht     

Alfons Zehnder  Dr. J. Komárek  Prof. Dr. S. Golubić  Prof. Dr. R. Y. Stanier  Dr. J. Komárek  Dr. J. Ludvík  Dr. L. Kováčik  Dr. Asta Almestrand  Prof. Dr. P. Compère  Dr. D. Mollenhauer  Dr. F. Hindák  Dr. T. P. Chang  Dr. Nagaraj Jeeji Bai  C. V. Seshadri  Dr. M. -E. Meffert  Dr. R. Oberhäuser  Dr. J. Overbeck  Dr. F. Hindák  Susan E. Campbell  Dr. Jaroslava Komárková  Dr. U. Uehlinger  Dr. F. Schanz  Dr. Alfons Zehnder 《Aquatic Sciences - Research Across Boundaries》1983,45(1):267-310

The 8th Symposium of the International Association for Cyanophyte Research IAC was attended by 29 specialists from 11 countries. The 19 oral presentations and discussions centered on the following themes: The basic principles of cyanophyte taxonomy (3 lectures), systematic problems of certain taxonomic groups (5 lectures), morphology (6 lectures) and ecology (5 lectures). The intensive discussions between representatives of the classical (european) taxonomic treatment of cyanophytes (based on morphological and ecological characteristics) and those representing the bacteriological study of ‘cyanobacteria’ were especially valuable. The central theme of the meeting was, however, the mutual microscopic study and discussion of problematic blue-greens from natural habitats, that were mostly collected during the three field trips into different areas of central Switzerland (Grimsel-Gotthard-Nufenen. Klewenalp. Gerzensee).   相似文献   

Use of statistical analysis to formulate conceptual models of geochemical behavior: water chemical data from the Botucatu aquifer in São Paulo state, Brazil     

Susan X. Meng  J. Barry Maynard 《Journal of Hydrology》2001,250(1-4):78-97

Water chemical data from the Botucatu Sandstone aquifer in the São Paulo State part of the Paraná Basin, Brazil, was evaluated using geochemical methods and two statistical analyses: cluster analysis and factor analysis. The results were used to develop a conceptual geochemical model, in which three geochemical regions were identified, and their chemical behavior was modeled. The characteristic chemicals, changing from the recharge area to the center of the basin, are: SiO₂—(HCO₃⁻ and Ca²⁺)—(Na⁺, CO₃²⁻, and SO₄²⁻). The distribution of the chemicals is interpreted as controlled by different water–rock interaction processes in the different regions. In the recharge area, dissolution of alkali–feldspar minerals in the sandstone is the main reaction observed; in the mid-section of the basin, calcite dissolution results in high calcium and bicarbonate concentration; in the center of the basin, leakage from underlying layers becomes the governing factor.  相似文献   

Effects of loads in the upper crust on estimates of the elastic thickness of the lithosphere   总被引：1，自引：0，他引：1  

Roger J. Banks  Susan C. Francis  Roger G. Hipkin 《Geophysical Journal International》2001,145(1):291-299

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The southwest Indian Monsoon over the last 18 000 years   总被引：7，自引：0，他引：7  

Jonathan Overpeck  David Anderson  Susan Trumbore  Warren Prell 《Climate Dynamics》1996,12(3):213-225

Previously published results suggest that the strength of the SW Indian Monsoon can vary significantly on century- to millenium time scales, an observation that has important implications for assessments of future climate and hydrologic change over densely populated portions of Asia. We present new, well-dated, multi-proxy records of past monsoon variation from three separate Arabian Sea sediment cores that span the last glacial maximum to late-Holocene. To a large extent, these records confirm earlier published suggestions that the monsoon strengthened in a series of abrupt events over the last deglaciation. However, our data provide a somewhat refined picture of when these events took place, and suggest the primacy of two abrupt increases in monsoon intensity, one between 13 and 12.5 ka, and the other between 10 and 9.5 ka. This conclusion is supported by the comparisons between our new marine data and published paleoclimatic records throughout the African-Asian monsoon region. The comparison of data sets further supports the assertion that maximum monsoon intensity lagged peak insolation forcing by about 3000 years, and extended from about 9.5 to 5.5 ka. The episodes of rapid monsoon intensification coincided with major shifts in North Atlantic-European surface temperatures and ice-sheet extent. This coincidence, coupled with new climate model experiments, suggests that the large land-sea thermal gradient needed to drive strong monsoons developed only after glacial conditions upstream of, and on, the Tibetan Plateau receded (cold North Atlantic sea-surface temperatures, European ice-sheets, and extensive Asian snow cover). It is likely that abrupt changes in seasonal soil hydrology were as important to past monsoon forcing as were abrupt snow-related changes in regional albedo. Our analysis suggests that the monsoon responded more linearly to insolation forcing after the disappearance of glacial boundary conditions, decreasing gradually after about 6 ka. Our data also support the possibility that significant century-scale decreases in monsoon intensity took place during the early to mid-Holocene period of enhanced monsoon strength, further highlighting the need to understand paleomonsoon dynamics before accurate assessments of future monsoon strength can be made.  相似文献