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101.
Inter-comparison of model-predicted wave heights with satellite altimeter measurements in the north Indian Ocean 总被引:1,自引:0,他引:1
A numerical model based on a wind-wave energy transport formulation of Toba is developed to generate hindcast wave height data for the equatorial and the north Indian Ocean, which is otherwise a data-sparse region. The intercomparison between model-predicted wave heights for three years (1987–1989) obtained utilising analysed surface wind fields' data, and model grid averaged GEOSAT Altimeter significant wave height data showed moderate match, particularly for HS greater than 1 m. 相似文献
102.
Abhijit Patil 《水文科学杂志》2013,58(1):118-133
Abstract This study presents a new methodology for estimation of input data measurement-induced uncertainty in simulated dissolved oxygen (DO) and nitrate-nitrogen (NO3-N) concentrations using the Hydrological Simulation Program–FORTRAN (HSPF) model and data from the Amite River, USA. Simulation results show that: (1) a multiplying factor of 1.3 can be used to describe the maximum error in temperature measurements; similarly, a multiplying factor of 1.9 was estimated to accommodate the maximum of ±5% error in rainfall measurements; (2) the uncertainty in simulated DO concentration due to positive temperature measurement errors can be described with a normal distribution, N(0.062, 0.567); (3) the uncertainty in simulated NO3-N concentration due to rainfall measurement errors follows a generalized extreme value distribution; and (4) the probability density functions can be utilized to determine the measurement-induced uncertainty in simulated DO and NO3-N concentrations according to the risk level acceptable in water quality management. Editor D. Koutsoyiannis Citation Patil, A. and Deng, Z.-Q., 2012. Input data measurement-induced uncertainty in watershed modelling. Hydrological Sciences Journal, 57 (1), 118–133. 相似文献
103.
Michael A. Dopita Daniela Calzetti Jesús Maíz Apellániz William P. Blair Knox S. Long Max Mutchler Bradley C. Whitmore Howard E. Bond John MacKenty Bruce Balick Marcella Carollo Michael Disney Jay A. Frogel Robert O’Connell Donald Hall Jon A. Holtzman Randy A. Kimble Patrick McCarthy Francesco Paresce Abhijit Saha Alistair R. Walker Joe Silk Marco Sirianni John Trauger Rogier Windhorst Erick Young 《Astrophysics and Space Science》2010,330(1):123-131
We present narrow band, continuum subtracted Hα, [S ii], Hβ, [O iii] and [O ii] data taken with the Wide Field Camera 3 on the Hubble Space Telescope in the nearby dwarf starburst galaxy NGC 4214. From these images, we identify seventeen new planetary nebula candidates, and seven supernova remnant candidates. We use the observed emission line luminosity function of the planetary nebulae to establish a new velocity-independent distance to NGC 4214. We conclude that the PNLF technique gives a reddening independent distance to NGC 4214 of 3.19±0.36 Mpc, and that our current best-estimate of the distance to this galaxy ids 2.98±0.13 Mpc. 相似文献
104.
Abhijit Basu 《Journal of the Geological Society of India》2009,73(4):528-536
Typically or arguably Ediacaran fossils (635 Ma to 543 Ma) are reported by several research groups from one unit of the Chhattisgarh
and two units of the Vindhyan Supergroups in peninsular India. Depositional ages of the host sediments, however, are inferred
to be ∼1000 Ma and ∼ 1630 Ma as determined by U-Pb dating of magmatic and detrital zircons in rhyolitic tuff (∼ porcellanite)
and sandstones, provenance considerations and paleopole positions. The contradiction of absolute ages results from inferring
the Ediacaran age strictly on the basis of fossils. I argue that the fossils reported from the Chhattisgarh and Vindhyan Supergroups
should be considered mostly Mesoproterozoic and late Proterozoic in age. I also argue that although the Ediacaran Period records
explosive diversity of preserved fossils, many forms very likely appeared much earlier with variable degrees of preservation
or none at all at times, and, that their age-ranges extend to the Paleoproterozoic. I hypothesize that the rate of increase
of biological diversity was lower than the rate of preservation in certain geological intervals, especially immediately after
extinction events. 相似文献
105.
We investigated the scenario of time-dependent diffusive interaction between dark matter and dark energy and showed that such a model can be accommodated within the observations of luminosity distanceredshift data in Supernova la(SN la)observations.We obtain constraints on different relevant parameters of this model from the observational data.We consider a homogeneous scalar field(t)driven by a k-essence Lagrangian of the form L=V(φ)F(X)with constant potential V(φ)=V,to describe the dynamics of dark energy in this model.Using the temporal behaviour of the FRW scale factor,the equation of state and total energy density of the dark fluid,extracted from the analysis of SN la(JLA)data,we have obtained the time-dependence of the k-essence scalar field and also reconstructed the form of the function F(X)in the k-essence Lagrangian. 相似文献
106.
Arindam Chakraborty Amit K. Ghosh Abhijit Mazumder 《Journal of the Geological Society of India》2017,90(4):428-436
Petrographic thin section analysis of the samples collected from the type section of Neil West Coast Formation, situated in the west coast of Neil Island yielded moderately preserved coralline red algae, benthic and planktic foraminifers, coral fragments, echinoid spines and gastropod shells. The coralline red algae are represented by both non-geniculate and geniculate forms. The non-geniculate forms belong to melobesids, lithophylloids and mastophoroides. The geniculate forms are represented by species of Amphiroa, Corallina, and Jania. However, the diversity and abundance of coralline algal forms are less in comparison to the benthic foraminifers those are represented by Amphistegina, Neorotalia, Ammonia, Elphidium, Operculina, Assilina, Amphisorus and texularids. Planktic foraminifers like Globigerinoides and other biogenic components viz., gastropod shells, echinoid spines and coral fragments are also common. A foraminiferal-algal grainstone facies has been recognized as observed in the field as well as in thin section analysis. The overall assemblage of the biogenic components and facies analysis indicate intertidal to near shore environment of deposition with high energy condition and increased hydrodynamic activity. 相似文献
107.
In this paper, the propagation of Love waves in a fiber‐reinforced layered medium lying over an elastic orthotropic half‐space under initial stress has been investigated. We have obtained the velocity equations for Love wave in this media. It is observed that propagation of Love wave is influenced by reinforced parameters and initial stressed parameter. The velocity of Love wave has been computed for three different cases. Our computed equation of Love wave coincides with the standard equation of Love wave for the case of homogeneous layer and homogeneous half‐space (AEH Love, 1911). To study the effect of reinforced and initial stressed parameters, we have computed the numerical values for phase velocity and plotted in several figures. It is observed that the phase velocity decreases with the increases of reinforced parameters and initial stressed parameter. Using MATLAB software, GUI has been developed to generalize the effect of various parameters. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
108.
Earlier investigations have shown that a power law relationship of the typeσ=aW b exists between the scattering coefficientσ and sea surface wind speedW at microwave frequencies. The coefficientsa andb are usually quoted for different frequencies, look angles, polarizations etc. This paper attempts to define the angular dependence using such a power law relationship in the quasi-specular range. 相似文献
109.
Geohazards Monitoring in Roma from InSAR and In Situ Data: Outcomes of the PanGeo Project 总被引:1,自引:0,他引:1
110.
The influence of nonlinearity on the dynamic response of cast-in-situ reinforced concrete piles subjected to strong vertical excitation was studied. Forced vibration test of single piles (L/d=10, 15, 20) and 2×2 pile groups (s/d=2, 3, 4 for each L/d) were conducted in the field for two different embedded conditions of pile cap. From the measured nonlinear response curves, the effective pile–soil system mass, stiffness and damping were determined and the nonlinear response curves were back-calculated using the theory of nonlinear vibration. The test results were compared with the continuum approach of Novak with dynamic interaction factor approach using both linear and linear-equivalent numerical methods. Reasonable match between the measured and predicted response was found for linear-equivalent methods by introducing a weak boundary-zone around the pile to approximately account for the nonlinear behaviour of pile–soil system. The test data were used to establish the empirical relationship in order to estimate the extent of soil separation around the pile with soil under vertical vibration. 相似文献