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891.
M. N. Berdichevsky N. S. Golubtsova Iv. M. Varentsov P. Yu. Pushkarev A. K. Rybin E. Yu. Sokolova 《Izvestiya Physics of the Solid Earth》2010,46(8):698-706
The paper presents the results of 2D inversion of deep magnetotelluric (MT) and magnetovariational (MV) soundings along the
Naryn Line. The method of partial (sequential) inversions is used. According to this method, at the first stage, magnetovariation
responses are used for the localization of deep anomalies of electrical conductivity, and then the magnetotelluric sounding
data are invoked to refine the structure of the host medium and the structural details in the upper part of the section. It
is shown that this approach enables one to estimate the informativeness of separate components of the electromagnetic field,
to reduce the distorting influence of the near-surface geoelectric inhomogeneities, and to increase the stability of the final
solution of the inverse problem. 相似文献
892.
Izvestiya, Physics of the Solid Earth - Abstract—When solving direct and inverse problems of magnetotellurics, magnetic permeability throughout model medium is conventionally assumed to be... 相似文献
893.
John R. Henderson Milton O. Smith Michael E. Zelinski 《Pure and Applied Geophysics》2014,171(3-5):763-777
The Comprehensive Nuclear Test Ban Treaty allows for Multi-Spectral and Infrared Imaging from an aircraft and on the ground to help reduce the search area for an underground nuclear explosion from the initial 1,000 km2. Satellite data, primarily from Landsat, have been used as a surrogate for aircraft data to investigate whether there are any multi-spectral features associated with the nuclear tests in Pakistan, India or North Korea. It is shown that there are multi-spectral observables on the ground that can be associated with the nominal surface ground zero for at least some of these explosions, and that these are likely to be found by measurements allowed by the treaty. 相似文献
894.
Yu. P. Tsvetkov O. M. Brekhov T. N. Bondar S. V. Filippov V. G. Petrov N. M. Tsvetkova A. Kh. Frunze 《Geomagnetism and Aeronomy》2014,54(2):263-268
Two global analytical models of the main magnetic field of the Earth (MFE) have been used to determine their potential in deriving an anomalous MFE from balloon magnetic surveys conducted at altitudes of ~30 km. The daily mean spherical harmonic model (DMSHM) constructed from satellite data on the day of balloon magnetic surveys was analyzed. This model for the day of magnetic surveys was shown to be almost free of errors associated with secular variations and can be recommended for deriving an anomalous MFE. The error of the enhanced magnetic model (EMM) was estimated depending on the number of harmonics used in the model. The model limited by the first 13 harmonics was shown to be able to lead to errors in the main MFE of around 15 nT. The EMM developed to n = m = 720 and constructed on the basis of satellite and ground-based magnetic data fails to adequately simulate the anomalous MFE at altitudes of 30 km. To construct a representative model developed to m = n = 720, ground-based magnetic data should be replaced by data of balloon magnetic surveys for altitudes of ~30 km. The results of investigations were confirmed by a balloon experiment conducted by Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation of the Russian Academy of Sciences and the Moscow Aviation Institute. 相似文献
895.
Kalyan Chakrabarti N. R. R. Ecka B. Mishra P. V. Ramesh Babu P. S. Parihar 《Journal of the Geological Society of India》2011,77(5):443-449
Ground Radiometric survey of Paleoproterozoic pyritiferous quartz-pebble conglomerate (QPC) occurring to the north of Pallahara
area led to the discovery of a QPC type uranium mineralisation near Mankarhachua village. Significant radioactivity is recorded
in three sub-parallel uraniferous QPC horizons with metamorphosed pebbly to medium grained recrystallised massive sandstones.
Detrital grains of uranothorite, thorite, radioactive allanite, monazite, zircon, minute uraninite grains in carbonaceous
matter and thucolite contributes to the radioactive phases present in QPC matrix. Adsorbed U on limonite and goethite, secondary
uranyl minerals in matrix, along bedding planes and fractures are commonly observed. This discovery has opened up a new horizon
for future exploration for QPC type uranium mineralization in the area. The paper presents observations on geology, radioactivity,
petrological and geochemical nature of the uraniferous QPC horizons. 相似文献
896.
Meththika Vithanage Anushka Upamali Rajapaksha Hasintha Wijesekara N. Weerarathne Yong Sik Ok 《Environmental Earth Sciences》2014,71(2):837-847
Inorganic arsenic (As) pesticides have been widely used for decades in many countries. However, insufficient data are available on the chemical speciation of inorganic arsenicals in tropical paddy soils. Inorganic As-containing pesticides were used in tropical countries, a few decades ago, however, their fate have not been studied. Hence, the objective of this study was to determine fractionation of inorganic arsenicals and to assess As lability with/without fertilizer application using a static incubation experiment. Eight soils from wet and dry regions of Sri Lanka were amended with 1,000 mg/kg arsenate for this purpose. The FT-IR and XRF results suggested that soils in the wet region were rich in Fe/Al-oxides. Paddy soils in the dry zone showed high As lability. These low-humic gley soils have low Fe/Al oxyhydroxide and alkaline pH. In contrast, the wet zone had soils with higher As retention capacity, high amounts of Fe/Al oxyhydroxide, and acidic pH. Arsenic lability increased considerably 30 days after fertilizer application. Overall, As lability was mainly influenced by soil mineralogical and chemical properties, i.e., Fe/Al oxyhydroxide, pH, organic matter, and fertilizer application. 相似文献
897.
The historical development of analytical aerial triangulation block adjustment is mentioned by way of introduction. The advantages of separating the plan and height adjustments are given and the observation equations of a typical adjustment section are analysed to show that this convenient practice is justified in normal circumstances. The principles of a direct solution of the normal equations suitable for a moderate-sized computer, are explained and developed in detail for the height adjustment. The advantages of tie-strips in the height adjustment are demonstrated and the difficulties which then arise are discussed. An approximate method which overcomes these difficulties is developed. Details of the computer programmes used are given in Appendix B. 相似文献
898.
Zhao-Jun?LiuEmail authorView authors OrcID profile Shoshiro?Minobe Yoshi?N.?Sasaki Mio?Terada 《Journal of Oceanography》2016,72(6):905-922
The future regional sea level (RSL) rise in the western North Pacific is investigated by dynamical downscaling with the Regional Ocean Modeling System (ROMS) with an eddy-permitting resolution based on three global climate models—MIROC-ESM, CSIRO-Mk3.6.0, and GFDL-CM3—under the highest greenhouse-gas emission scenario. The historical run is forced by the air-sea fluxes calculated from Coordinated Ocean Reference Experiment version 2 (COREv2) data. Three future runs—ROMS-MIROC, ROMS-CSIRO, and ROMS-GFDL—are forced with an atmospheric field constructed by adding the difference between the climate model parameters for the twenty-first and twentieth century to fields in the historical run. In all downscaling, the RSL rise along the eastern coast of Japan is generally half or less of the RSL rise maxima off the eastern coast. The projected regional (total) sea level rises along the Honshu coast during 2081–2100 relative to 1981–2000 are 19–25 (98–104), 6–15 (71–80), and 8–14 (80–86) cm in ROMS-MIROC, ROMS-CSIRO, and ROMS-GFDL, respectively. The discrepancies of the RSL rise along the Honshu coast between the climate models and downscaling are less than 10 cm. The RSL changes in the Kuroshio Extension (KE) region in all downscaling simulations are related to the changes of KE (northward shift or intensification) with climate change. 相似文献
899.
N. Misra P. K. Panda B. K. Parida B. K. Mishra 《International Journal of Environmental Science and Technology》2016,13(11):2735-2756
Driven by policies aimed at enhancing energy security and mitigating greenhouse gas emissions, the production and use of biofuels have significantly increased in recent years. Microalgae owing to its multiple advantages which include high lipid content, sustainable biomass production, effective land and water utilization are the most potential biofuel feedstock that can provide drop-in fossil fuel replacements without stimulating competition for agricultural resources and are considered to be more environmentally benign than the first- and second-generation biofuel feedstocks. However, there are many existing technical and scientific impediments that are yet to be resolved. Keeping this in view, the present review provides a concise account of the microalgal species known to accumulate high levels of lipid and describes the main factors that should be taken into consideration while selecting suitable algal strains for mass cultivation. The underlining advantages and limitations of raceway pond and photobioreactor cultivation systems are also examined. The recent advances in genetic engineering of microalgae to improve biomass and lipid productivity are then highlighted, which include the ongoing debate over the biosafety issues pertinent to the use of genetically modified algae. Furthermore, a wide range of high-value products that can be co-produced from microalgae have been discussed. The review concludes with a comprehensive summary of the major techno-economic constraints to commercialization of algal-derived biofuels along with promising methods for overcoming these challenges in order to produce cost-competitive and environmentally sustainable biofuel. 相似文献
900.
A. M. Nikishin K. O. Sobornov A. V. Prokopiev S. V. Frolov 《Moscow University Geology Bulletin》2010,65(1):1-16
This paper presents characteristics of the structural regions surrounding the Siberian Platform and discusses the Vendian-present
time evolution of the Siberian Paleocontinent with the Siberian Craton making up its nucleus. It shows that the paleocontinent
underwent significant intraplate compressional deformations with vertical movements and formation of inversion structural
features within broad areas. Such epochs of deformation took place at the Riphean-Vendian time boundary, during the Late Paleozoic,
Late Triassic, Early Cretaceous, and during the Late Cenozoic. The principal rifting events took place during the Middle-Late
Devonian. The paper presents paleotectonic reconstructions of East Siberia at several key time intervals. 相似文献