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111.
Land use and marine spatial planning processes are increasingly supported by systematic assessment techniques, particularly by multi‐criteria spatial analysis methods. This has been facilitated by the growing release and uptake of web‐mapping tools, which contribute to transparent, consistent, and informed planning processes and decisions. This article reviews the usability, functionality, and applicability of contemporary planning web‐mapping tools to identify the state‐of‐the‐art and future prospects. The review reveals that interfaces are increasingly available and intuitively applicable by non‐specialized users. Basic map navigation and data querying functionality is being expanded to incorporate advanced map‐making and online data geoprocessing capabilities that enable deriving new data and insights. However, the majority of published planning web tools are one‐off solutions, and a disconnect between research and practice is rendering many of these inaccessible or obsolete. Despite the significant progress made in advancing their provision in the last decade, there is a need for developing transferable interfaces that are maintained beyond project end dates, for them to effectively and consistently support planning processes. 相似文献
112.
We describe for the first time the generation and measurement of capillary waves in a water surface in a wind tunnel running with air at pressures of 15-1000 mbar. These experiments suggest a stronger dependence of wave generation on atmospheric density than the simple proportionality that might be expected from energy transfer arguments. Additionally, airflow over a nonaqueous fluid (kerosene) was found to produce waves of higher amplitude than for water under the same conditions. These preliminary results may indicate different efficiencies of wave generation on other planets, for which empirical terrestrial relations therefore do not apply, and thus may have a bearing on the lack of strong shoreline features on Mars and the possibility of specular glints from hydrocarbon lakes on Titan. 相似文献
113.
The authors use 1981 census data to create a cartogram showing the counties of New Zealand in proportion to their population. 相似文献
114.
Erin F. Owen Alan D. Wanamaker Jr. Bernd R. Schöne 《Geochimica et cosmochimica acta》2008,72(19):4687-4698
The relationship between stable isotope composition (δ13C and δ18O) in seawater and in larval shell aragonite of the sea scallop, Placopecten magellanicus, was investigated in a controlled experiment to determine whether isotopes in larval shell aragonite can be used as a reliable proxy for environmental conditions. The linear relationship between δ13CDIC and δ13Caragonite (r2 = 0.97, p < 0.0001, RMSE = 0.18) was:
δ13CDIC=1.15(±0.05)∗δ13Caragonite-0.85(±0.04) 相似文献
115.
William D. Burgos Jeffrey T. McDonough Gengxin Zhang Shelly D. Kelly Kenneth M. Kemner 《Geochimica et cosmochimica acta》2008,72(20):4901-4915
The reduction of uranium(VI) by Shewanella oneidensis MR-1 was studied to examine the effects of bioreduction kinetics and background electrolyte on the physical properties and reactivity to re-oxidation of the biogenic uraninite, UO2(s). Bioreduction experiments were conducted with uranyl acetate as the electron acceptor and sodium lactate as the electron donor under resting cell conditions in a 30 mM NaHCO3 buffer, and in a PIPES-buffered artificial groundwater (PBAGW). MR-1 was cultured in batch mode in a defined minimal medium with a specified air-to-medium volume ratio such that electron acceptor (O2) limiting conditions were reached just when cells were harvested for subsequent experiments. The rate of U(VI) bioreduction was manipulated by varying the cell density and the incubation temperature (1.0 × 108 cell ml−1 at 20 °C or 2.0 × 108 cell ml−1 at 37 °C) to generate U(IV) solids at “fast” and “slow” rates in the two different buffers. The presence of Ca in PBAGW buffer altered U(VI) speciation and solubility, and significantly decreased U(VI) bioreduction kinetics. High resolution transmission electron microscopy was used to measure uraninite particle size distributions produced under the four different conditions. The most common primary particle size was 2.9-3.0 nm regardless of U(VI) bioreduction rate or background electrolyte. Extended X-ray absorption fine-structure spectroscopy was also used to estimate uraninite particle size and was consistent with TEM results. The reactivity of the biogenic uraninite products with dissolved oxygen was tested, and neither U(VI) bioreduction rate nor background electrolyte had any statistical effect on oxidation rates. With MR-1, uraninite particle size was not controlled by the bioreduction rate of U(VI) or the background electrolyte. These results for MR-1, where U(VI) bioreduction rate had no discernible effect on uraninite particle size or oxidation rate, contrast with our recent research with Shewanella putrefaciens CN32, where U(VI) bioreduction rate strongly influenced both uraninite particle size and oxidation rate. These two studies with Shewanella species can be viewed as consistent if one assumes that particle size controls oxidation rates, so the similar uraninite particle sizes produced by MR-1 regardless of U(VI) bioreduction rate would result in similar oxidation rates. Factors that might explain why U(VI) bioreduction rate was an important control on uraninite particle size for CN32 but not for MR-1 are discussed. 相似文献
116.
Elizabeth Keegan Stephan Richter Ian Kelly Henri Wong Patricia Gadd Heinz Kuehn Adolfo Alonso-Munoz 《Applied Geochemistry》2008
Elemental and isotopic ratio analyses of U ore concentrate samples, from the 3 operating U mining facilities in Australia, were carried out to determine if significant variations exist between their products, thereby allowing the U ore concentrate’s origin to be identified. Elemental analyses were conducted using inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF). Lead isotope ratios were measured using ICP-MS and U isotope analyses were conducted using thermal ionisation mass spectrometry (TIMS). Minute quantities of sample, such as that obtained from a swipe, were also examined for elemental concentrations using secondary ion mass spectrometry (SIMS). The results of multivariate statistical analysis show clear patterns in the trace elemental composition of the processed U ores, indicating that it is possible to use this feature as a unique identifier of an Australian U ore concentrate’s source. Secondary ion mass spectrometry analyses also allow individual particles to be differentiated using this ‘fingerprinting’ technique. Isotope ratios determined using TIMS reveal that there is a significant difference in the n(234U)/n(238U) isotope ratio between the U ore concentrate from each mine. 相似文献
117.
Amanda R. Lusas Brenda L. Hall Thomas V. Lowell Meredith A. Kelly Ole Bennike Laura B. Levy William Honsaker 《Journal of Paleolimnology》2017,57(4):321-341
Prediction of future Arctic climate and environmental changes, as well as associated ice-sheet behavior, requires placing present-day warming and reduced ice extent into a long-term context. Here we present a record of Holocene climate and glacier fluctuations inferred from the paleolimnology of small lakes near Istorvet ice cap in East Greenland. Calibrated radiocarbon dates of organic remains indicate deglaciation of the region before ~10,500 years BP, after which time the ice cap receded rapidly to a position similar to or less extensive than present, and lake sediments shifted from glacio-lacustrine clay to relatively organic-rich gyttja. The lack of glacio-lacustrine sediments throughout most of the record suggests that the ice cap was similar to or smaller than present throughout most of the Holocene. This restricted ice extent suggests that climate was similar to or warmer than present, in keeping with other records from Greenland that indicate a warm early and middle Holocene. Middle Holocene magnetic susceptibility oscillations, with a ~200-year frequency in one of the lakes, may relate to solar influence on local catchment processes. Following thousands of years of restricted extent, Istorvet ice cap advanced to within 365 m of its late Holocene limit at ~AD 1150. Variability in the timing of glacial and climate fluctuations, as well as of sediment organic content changes among East Greenland lacustrine records, may be a consequence of local factors, such as elevation, continentality, water depth, turbidity, and seabirds, and highlights the need for a detailed spatial array of datasets to address questions about Holocene climate change. 相似文献
118.
The modern geomagnetic field is usually expressed as a spherical harmonic expansion. Although the palaeomagnetic record is very incomplete in both space and time, sufficient data are available from a span of ages to generate time-averaged spherical harmonic field models with many degrees of freedom. Here three data sets are considered: directional measurements from lavas, inclination measurements from ocean sediments, and intensity measurements from lavas. Individual data are analysed, as well as site-averages, using the same methods that have been developed for the modern field, to give models for the past 5 Myr. The normal-polarity field model has an axial-dipole intensity similar to that of the modern-day field, whilst the equatorial-dipole component is very much smaller. The field is not axisymmetric, but shows flux concentrations at the core's surface under Canada and Siberia similar to those observed in the field over historical timescales. Tests on synthetic data show that it is unlikely that these similarities result from the overprinting of the palaeomagnetic field due to inadequate cleaning of the samples. The reverse-polarity field model does not show such obvious features, but this may be due to the sparsity of the data.
The patterns observed in the normal-polarity field, with persistent features in the northern hemisphere and a smooth southern hemisphere, could be explained if the present pattern of secular variation is typical of the past several million years. This would reveal itself as large variations over time in the direction of the magnetic vector in regions of high secular variation, with relatively little change over quieter regions. However, we have been unable to find any evidence for a geographical pattern of secular variation in the data. 相似文献
The patterns observed in the normal-polarity field, with persistent features in the northern hemisphere and a smooth southern hemisphere, could be explained if the present pattern of secular variation is typical of the past several million years. This would reveal itself as large variations over time in the direction of the magnetic vector in regions of high secular variation, with relatively little change over quieter regions. However, we have been unable to find any evidence for a geographical pattern of secular variation in the data. 相似文献
119.
120.
Kriging with imprecise (fuzzy) variograms. II: Application 总被引:2,自引:0,他引:2
The geostatistical analysis of soil liner permeability is based on 20 measurements and imprecise prior information on nugget effect, sill, and range of the unknown variogram. Using this information, membership functions for variogram parameters are assessed and the fuzzy variogram is constructed. Both kriging estimates and estimation variances are calculated as fuzzy numbers from the fuzzy variogram and data points. Contour maps are presented, indicating values of the kriged permeability and the estimation variance corresponding to selected membership values called levels. 相似文献