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91.
Ocean Science Journal - Thamnaconus modestus is a commercially important species that is widely distributed in the Northwest Pacific region. To investigate the genetic diversity, demographic... 相似文献
92.
93.
Near real-time quantitative precipitation estimates are required for many applications including weather forecasting, flood forecasting, crop management, forest fire prevention, hydropower production, and dam safety. Since April 2011, such a product has been available from Environment and Climate Change Canada for a domain covering all North America. This product, known as the Regional Deterministic Precipitation Analysis, is generated using the Canadian Precipitation Analysis (CaPA) system. Although it was designed for near real-time use, an archive of pre-operational and operational products going back to 2002 is now available and has been used in numerous studies. This paper presents a review of the various scientific publications that have reported either using or evaluating CaPA products. We find that the product is used with success both for scientific studies and operational applications and compares well with other precipitation datasets. We summarize the strengths and weaknesses of the system as reported in the literature. We also provide users with information on how the system works, how it has changed over time, and how the archived and near real-time analyses can be accessed and used. We finally briefly report on recent and upcoming improvements to the product based, in part, on the results of this literature review. 相似文献
94.
Annadasankar Roy Hemant Mohokar Diksha Pant Uday Kumar Sinha G. N. Mendhekar 《水文科学杂志》2020,65(6):951-968
ABSTRACTMultivariate statistical analysis and inverse geochemical modelling techniques were employed to deduce the mechanism of groundwater evolution in the hard-rock terrain of Telangana, South India. Q-mode hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to extract the hydrogeochemical characteristics and classify the groundwater samples into three principal groups. Use of thermodynamic stability diagrams and inverse geochemical modelling in PHREEQC identified the chemical reactions controlling hydrogeochemistry of each of the groups obtained from statistical analysis. The model output showed that a few phases are governing the water chemistry in this area and the geochemical reactions responsible for evolution of groundwater chemistry along the flow path are (i) dissolution of evaporite minerals (dolomite, halite); (ii) dissolution of primary silicate minerals (albite, anorthite, K-feldspar, biotite); (iii) precipitation of secondary silicate minerals (kaolinite, quartz, gibbsite, Ca-montmorillonite) along with anhydrite and calcite; and (iv) reverse ion exchange processes. 相似文献
95.
96.
Polycyclic aromatic (PAH) and aliphatic hydrocarbon compositions, organic carbon, nitrogen and lignin contents were determined in whole, unfractionated sediment from the Washington continental shelf and in discrete sediment fractions separated by particle size and density. At least 20 to 25% of perylene and PAH derived from pyrolytic processes and 50% of the retene measured in whole sediment are contained within organic C- and lignin-rich panicles of density ≤ 1.9 g/cc. These particles, which include primarily vascular plant remains and bits of charcoal, comprise less than 1% of the total sediment weight. In contrast, a series of methylated phenanthrene homologs, possibly of fossil origin, are concentrated in some component of the more dense, lithic matrix of the sediment. Equilibrium models of PAH sorption/desorption from aqueous phase onto small particles of high surface area do not appear applicable to the behavior of the major PAH types identified in this aquatic environment. 相似文献
97.
A. Mascle R. Vially E. Deville B. Biju-Duval J.P. Roy 《Marine and Petroleum Geology》1996,13(8):941-961
The Southeast Basin of France is the thickest onshore French sedimentary basin which contains locally as much as 10 km of Mesozoic-Cenozoic sediment. Basin development occurred in several stages between late Carboniferous and late Cretaceous times. Partial tectonic inversion took place during two compressive events, the so-called ‘Pyrenean’ and ‘Alpine’ phases of late Cretaceous-early Tertiary and late Tertiary ages respectively. They are separated by an intervening stretching event of Oligocene age, which further south resulted in the opening of the western Mediterranean oceanic basin. As a result of this complex tectonic history, structural traps were difficult to image on the seismic data shot during the first phase of exploration prior to 1980. Oil and gas natural seeps, and shows in several wells, indicate that some petroleum systems are, or have been active, at least in some places.The present erosional western margin of the basin is more or less superimposed on the initial Triassic-Jurassic margin. Margin subsidence and Tertiary inversion are discussed using regional sections on which the polyphase history of the entire basin is well shown. These sections are located on three major segments where the Mesozoic margin is either partly preserved (Ardèche), or has been partly inverted in late Tertiary times (Vercors-Chartreuse), or has been completely inverted in early Tertiary times (Corbières-eastern Pyrenees). 1-D ‘Genex’ basin modelling on the Ardèche segment, and 2-D ‘Thrustpack’ structural-maturity modelling in the Vercors-Chartreuse segment are used to further assess the remaining petroleum plays. 相似文献
98.
Manish P. Kale Shirish A. Ravan P. S. Roy Sarnam Singh 《Journal of the Indian Society of Remote Sensing》2009,37(3):457-471
Satellite remote sensing is a proven tool for mapping landuse patterns and estimating vegetation biomass/carbon. Present study
aims at estimating the potential of forests of Radhanagari WLS (Western Ghats, India) to sequester the atmospheric carbon-di-oxide,
using ground based observations coupled with satellite remote sensing. The study area was stratified for dominant forest types
based on the structure and composition of vegetation and elevation variations. Permanent sample plots were laid down in these
homogeneous vegetation strata (HVS) to make different observations during time 1 and time 2. Carbon sequestration by plantations
was also studied and compared with natural forests. Species and area-specific biomass equations were used for estimating carbon
pool and sequestration. Among natural forests ‘mixed moist deciduous’ forests exhibited highest sequestration rate (8%), whereas,
plantation as obvious had a comparatively higher sequestration rate than natural forests (20.27%). Total carbon sequestration
by forests of the Radhanagari WLS between 2004 and 2006 is 78742.09 tons. Eligible land for reforestation activity under clean
development mechanism (CDM) of Kyoto Protocol was identified using satellite remote sensing using 1989 and 2005 datasets and
it was observed that the potential land that can be used for reforestation activity is 10080 ha. 相似文献
99.
Vishnu Reddy Juan A. Sanchez Andreas Nathues Nicholas A. Moskovitz Jian-Yang Li Edward A. Cloutis Ken Archer Roy A. Tucker Michael J. Gaffey J. Paul Mann Holger Sierks Ulrich Schade 《Icarus》2012,217(1):153-168
Phase angle and temperature are two important parameters that affect the photometric and spectral behavior of planetary surfaces in telescopic and spacecraft data. We have derived photometric and spectral phase functions for the Asteroid 4 Vesta, the first target of the Dawn mission, using ground-based telescopes operating at visible and near-infrared wavelengths (0.4–2.5 μm). Photometric lightcurve observations of Vesta were conducted on 15 nights at a phase angle range of 3.8–25.7° using duplicates of the seven narrowband Dawn Framing Camera filters (0.4–1.0 μm). Rotationally resolved visible (0.4–0.7 μm) and near-IR spectral observations (0.7–2.5 μm) were obtained on four nights over a similar phase angle range. Our Vesta photometric observations suggest the phase slope is between 0.019 and 0.029 mag/deg. The G parameter ranges from 0.22 to 0.37 consistent with previous results (e.g., Lagerkvist, C.-I., Magnusson, P., Williams, I.P., Buontempo, M.E., Argyle, R.W., Morrison, L.V. [1992]. Astron. Astrophys. Suppl. Ser. 94, 43–71; Piironen, J., Magnusson, P., Lagerkvist, C.-I., Williams, I.P., Buontempo, M.E., Morrison, L.V. [1997]. Astron. Astrophys. Suppl. Ser. 121, 489–497; Hasegawa, S. et al. [2009]. Lunar Planet. Sci. 40. ID 1503) within the uncertainty. We found that in the phase angle range of 0° < α ? 25° for every 10° increase in phase angle Vesta’s visible slope (0.5–0.7 μm) increases 20%, Band I and Band II depths increase 2.35% and 1.5% respectively, and the BAR value increase 0.30. Phase angle spectral measurements of the eucrite Moama in the lab show a decrease in Band I and Band II depths and BAR from the lowest phase angle 13° to 30°, followed by possible small increases up to 90°, and then a dramatic drop between 90° and 120° phase angle. Temperature-induced spectral effects shift the Band I and II centers of the pyroxene bands to longer wavelengths with increasing temperature. We have derived new correction equations using a temperature series (80–400 K) of HED meteorite spectra that will enable interpretation of telescopic and spacecraft spectral data using laboratory calibrations at room temperature (300 K). 相似文献
100.
Fractal Analysis of the Complexity of United States Coastlines 总被引:10,自引:0,他引:10
Coastlines have long been used as a principal example of a natural feature that exhibits fractal structure. With the advent of large digitized databases, it has become possible to examine in detail large regions of coast and to examine differences in complexity, as measured by the fractal dimension, among regions. In this study, we have determined the fractal dimension of the Atlantic and Pacific coastlines of the conterminous United States. The traditional divider method was used in obtaining the fractal dimension of each coastline arc from the NOAA Medium-Resolution Shoreline Data Set. On average, the Atlantic coast has much higher fractal dimension than the Pacific coast. The results also indicate that the complexity of the Atlantic coast increases toward low latitudes. These results have implications for the interpretation of species distributions and diversity patterns along the coast and for the understanding of the dynamics of biotic recovery from mass extinctions. 相似文献