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61.
Methods of Three-part Quantitative Assessments of Undiscovered Mineral Resources: Examples from Victoria,Australia 总被引:1,自引:0,他引:1
Vladimir Lisitsin 《Mathematical Geosciences》2010,42(5):571-582
Quantitative mineral resource assessments following the 3-part form rely on grade and tonnage models and probabilistic estimates
of the number of undiscovered deposits. Assessments completed in Victoria, Australia, indicate that undiscovered mineral resources
can be effectively estimated using grade and tonnage sub-models constructed using only medium- and large-tonnage deposits.
Numbers of undiscovered deposits can be estimated on the basis of expert judgement or entirely by statistical means. Appropriate
mathematical aggregation of individual expert views, expressed at interactive expert workshops, provides robust estimates
of the number of undiscovered deposits. Underestimation of uncertainty, which is common in expert judgement, can be compensated
by the statistical modification of individual interval estimates. In this study, the linear opinion pool was used as a simple
and robust method of mathematical aggregation of multiple expert estimates of the number of undiscovered deposits. A general
regression model, which estimates numbers of undiscovered deposits based on the size of the geologically permissive area and
the median deposit tonnage, provided results generally compatible with those based on expert judgement or local deposit density
models. 相似文献
62.
Application of SWACI products as ionospheric correction for single-point positioning: a comparative study 总被引:1,自引:0,他引:1
In Global Navigation Satellite Systems (GNSS) using L-band frequencies, the ionosphere causes signal delays that correspond with link related range errors of up to 100 m. In a first order approximation the range error is proportional to the total electron content (TEC) of the ionosphere. Whereas this first order range error can be corrected in dual-frequency measurements by a linear combination of carrier phase- or code-ranges of both frequencies, single-frequency users need additional information to mitigate the ionospheric error. This information can be provided by TEC maps deduced from corresponding GNSS measurements or by ionospheric models. In this paper we discuss and compare different ionospheric correction methods for single-frequency users. The focus is on the comparison of the positioning quality using dual-frequency measurements, the Klobuchar model, the NeQuick model, the IGS TEC maps, the Neustrelitz TEC Model (NTCM-GL) and the reconstructed NTCM-GL TEC maps both provided via the ionosphere data service SWACI (http://swaciweb.dlr.de) in near real-time. For that purpose, data from different locations covering several days in 2011 and 2012 are investigated, including periods of quiet and disturbed ionospheric conditions. In applying the NTCM-GL based corrections instead of the Klobuchar model, positioning accuracy improvements up to several meters have been found for the European region in dependence on the ionospheric conditions. Further in mid- and low-latitudes the NTCM-GL model provides results comparable to NeQuick during the considered time periods. Moreover, in regions with a dense GNSS ground station network the reconstructed NTCM-GL TEC maps are partly at the same level as the final IGS TEC maps. 相似文献
63.
The improvement of greenhouse gas inventory as a tool for reduction emission uncertainties for operations with oil in the Russian Federation 总被引:2,自引:0,他引:2
Nina E. Uvarova Vladimir V. Kuzovkin Sergey G. Paramonov Michael L. Gytarsky 《Climatic change》2014,124(3):535-544
The high quality inventory is an important step to greenhouse gas emission mitigation. The inventory quality is estimated by means of the uncertainty analysis. The level of uncertainty depends upon the reliability of activity data and the parameters used. An attempt has been made to improve the accuracy of the estimates through a shift from production-based method (IPCC Tier 1) (IPCC 2000) to enhanced combination of production-based and mass balance methods (IPCC Tier 2) (IPCC 2006) in the estimation of emissions from operations with oil that are key in the national greenhouse gas inventory of the Russian Federation. The IPCC Tier 2 (IPCC 2006) was adapted for the national conditions. The greenhouse gas emissions were calculated for 1990 to 2009 with the use of both methods. The quantitative uncertainty assessment of the calculations was performed, and the outcomes were compared. The comparison showed that the estimates made with the use of higher tier method resulted in higher accuracy and lower uncertainties (26 % respectively compared to previously derived 54 %). 相似文献
64.
Hui Ding Richard J. Greatbatch Wonsun Park Mojib Latif Vladimir A. Semenov Xuguang Sun 《Climate Dynamics》2014,42(1-2):367-379
The variability of the East Asian summer monsoon (EASM) is studied using a partially coupled climate model (PCCM) in which the ocean component is driven by observed monthly mean wind stress anomalies added to the monthly mean wind stress climatology from a fully coupled control run. The thermodynamic coupling between the atmospheric and oceanic components is the same as in the fully coupled model and, in particular, sea surface temperature (SST) is a fully prognostic variable. The results show that the PCCM simulates the observed SST variability remarkably well in the tropical and North Pacific and Indian Oceans. Analysis of the rainfall-SST and rainfall-SST tendency correlation shows that the PCCM exhibits local air-sea coupling as in the fully coupled model and closer to what is seen in observations than is found in an atmospheric model driven by observed SST. An ensemble of experiments using the PCCM is analysed using a multivariate EOF analysis to identify the two major modes of variability of the EASM. The PCCM simulates the spatial pattern of the first two modes seen in the ERA40 reanalysis as well as part of the variability of the first principal component (correlation up to 0.5 for the model ensemble mean). Different from previous studies, the link between the first principal component and ENSO in the previous winter is found to be robust for the ensemble mean throughout the whole period of 1958–2001. Individual ensemble members nevertheless show the breakdown in the relationship before the 1980’s as seen in the observations. 相似文献
65.
66.
Nenad Grba Aleksandra Šajnović Ksenija Stojanović Vladimir Simić Branimir Jovančićević Goran Roglić Vladisav Erić 《Chemie der Erde / Geochemistry》2014
Sedimentary rocks from the saline formation of the Lopare Basin were investigated. Sediments contain a moderate amount of immature to marginally mature algal organic matter deposited under slightly reducing to anoxic and slightly saline to hypersaline conditions. Almost all of the samples contain β-carotane in a relatively high quantity, and in some, it represents the most abundant compound in the total distribution of hydrocarbons. The objective of the study was to determine the conditions that are favourable to precursors of β-carotene and/or the preservation of the carotenoid hydrocarbon skeleton. Moreover, the dominant transformation pathways of β-carotene under different redox and salinity conditions, which lead to the formation of aromatic carotenoids were defined. 相似文献
67.
Consideration of within-earthquake ground-motion correlation is essential for the estimation of seismic hazards, damage, and loss for spatially distributed systems. In many seismically active regions, the strong motion data of real engineering significance are completely unavailable or very scarce. The absence of necessary data does not allow developing regional empirical correlation models, and the models obtained for other regions should be used with correspondent sensitivity analysis. The level of within-earthquake correlation may vary in broad range; therefore, development of correspondent criteria for selection from available models is important. In this paper, we analyzed the performance of a system of critical elements of electric power network (substations) depending on variations in within-earthquake correlation. The performance is described as probability of different levels of non-functionality, i.e., percentage of area suffering power outage, and probability of expected number of customers without power. We have shown that the proper choice of the within-earthquake correlation model is critical in comprehensive estimations of functionality of substations in electrical power system. Skipping the ground-motion variability and within-earthquake correlation may lead to unreliable results. Relevance of geology-based within-earthquake correlation models has been demonstrated, and a scheme, which allows reducing uncertainty in the choice of realistic correlation, has been proposed. 相似文献
68.
Alla BRYANSKAYA Alexey ROZANOV Tatyana MALUP Taisiya ALESHINA Elena LAZAREVA Oxana TARAN Tatyana GORYACHKOVSKAYA Vladimir IVANISENKO Sergey PELTEK 《《地质学报》英文版》2014,88(Z1):61-62
正Salt Lake is one of the lakes in the system,consisting of a huge amount of salt and bitter-salty lakes in Novosibirsk Oblast and Altai Krai.These lakes are unique and highly unstable systems where the parameters of geochemical 相似文献
69.
正1 Introduction Alkaline Lake Khilganta located in a steppe zone of South Siberia(N 50°42'535,E 115°06'086)is unique among adjacent lakes because of a development of a thick(up to 3 cm)cyanobacterial mat dominated by 相似文献
70.
Vladimir V. Svetsov 《Planetary and Space Science》2005,53(12):1205-1220
Vertical impacts on the Earth of asteroids 500-3000 km in diameter at 15 km/s have been numerically modelled using the hydrodynamic SOVA code. This code has been modified for the spherical system of coordinates well suited for simulations of very large impacts when the entire Earth is involved in motion. The simulations include cratering process, upward motion of deep mantle layers, fall of ejecta on the Earth, escape of matter to space, and formation of rock vapour atmospheres. The calculations were made for the period preceding disappearance of rock vapour atmospheres caused by radiation several years after the largest impacts. For very large vertical impacts at 15 km/s, escaping masses proved to be negligibly small. Quantities of kinetic, internal, potential, and radiated away energies are obtained as functions of time and space. After the impacts, a global layer of condensed ejecta covers the whole of the Earth's surface and the ejecta energy is sufficient to vaporise an ocean 3 km deep. The mass of rock vapour atmosphere is 10-23% of the impactor mass. This atmosphere has a greater mass than the water atmosphere if impactor is 2000 km in diameter or larger. 相似文献