Distinctive Features of Two Genetic Types of Sulfide Ores in the Central Atlantic     

Gablina  I. F. 《Lithology and Mineral Resources》2022,57(2):143-160

Lithology and Mineral Resources - The results of long-term studies of the localization conditions, morphology, structure, mineral and chemical compositions of modern ocean sulfide ores, carbonate...  相似文献   

Color of the Corona Continuum of July 11, 1991     

Kim  I. S.  Krusanova  N. L.  Popov  V. V.  Osokin  A. R.  Mironova  I. V. 《Geomagnetism and Aeronomy》2020,60(4):441-445

Geomagnetism and Aeronomy - The color of the coronal continuum was determined from observations in order to search for manifestations of coronal expansion. A brief review of studies determining the...  相似文献   

Electron Energy Spectra and e–e Bremsstrahlung from Anisotropic Electron Distributions in Extreme Solar Flares     

Oparin  I. D.  Charikov  Yu. E.  Ovchinnikova  E. P.  Shabalin  A. N. 《Geomagnetism and Aeronomy》2020,60(7):889-895

Geomagnetism and Aeronomy - We study the electron energy spectra of two powerful solar flares SOL2003-10-28T 1106:16 (GOES class X17.2) and SOL2002-07-23T 0018:16 (X4.8) analyzing the HXR and...  相似文献   

Information–Modeling Complex for Assessing the Hydroenvironmental Conditions of Reservoirs     

Motovilov  Yu. G.  Golosov  S. D.  Datsenko  Yu. S.  Zverev  I. S.  Puklakov  V. V.  Fashchevskaya  T. B. 《Water Resources》2020,47(5):751-762

Water Resources - An Information–Modeling Complex has been developed for the information support of managerial decision making in the field of rational use, protection, and restoration of...  相似文献   

Terrestrial LiDAR monitoring of coastal foredune evolution in managed and unmanaged systems     

I. Conery  K. Brodie  N. Spore  J. Walsh 《地球表面变化过程与地形》2020,45(4):877-892

Coastal dunes provide essential protection for infrastructure in developed regions, acting as the first line of defence against ocean-side flooding. Quantifying dune erosion, growth and recovery from storms is critical from management, resiliency and engineering with nature perspectives. This study utilizes 22 months of high-resolution terrestrial LiDAR (Riegl VZ-2000) observations to investigate the impact of management, anthropogenic modifications and four named storms on dune morphological evolution along ~100 m of an open-coast, recently nourished beach in Nags Head, NC. The influences of specific management strategies – such as fencing and plantings – were evaluated by comparing these to the morphologic response at an unmanaged control site at the USACE Field Research Facility (FRF) in Duck, NC (33 km to the north), which experienced similar environmental forcings. Various beach-dune morphological parameters were extracted (e.g. backshore-dune volume) and compared with aeolian and hydrodynamic forcing metrics between each survey interval. The results show that LiDAR is a useful tool for quantifying complex dune evolution over fine spatial and temporal scales. Under similar forcings, the managed dune grew 1.7 times faster than the unmanaged dune, due to a larger sediment supply and enhanced capture through fencing, plantings and walkovers. These factors at the managed site contributed to the welding of the incipient dune to the primary foredune over a short period of less than a year, which has been observed to take up to decades in natural systems. Storm events caused alongshore variable dune erosion primarily to the incipient dune, yet also caused significant accretion, particularly along the crest at the managed site, resulting in net dune growth. Traditional empirical Bagnold equations correlated with observed trends of backshore-dune growth but overpredicted magnitudes. This is likely because these formulations do not encompass supply-limiting factors and erosional processes. © 2019 John Wiley & Sons, Ltd.  相似文献   

Structure-specific selection of earthquake ground motions for the reliable design and assessment of structures   总被引：1，自引：1，他引：0  

E. I. Katsanos  A. G. Sextos 《Bulletin of Earthquake Engineering》2018,16(2):583-611

A decision support process is presented to accommodate selecting and scaling of earthquake motions as required for the time domain analysis of structures. Code-compatible suites of seismic motions are provided being, at the same time, prequalified through a multi-criterion approach to induce response parameters with reduced variability. The latter is imperative to increase the reliability of the average response values, normally required for the code-prescribed design verification of structures. Structural attributes like the dynamic characteristics as well as criteria related to variability of seismic motions and their compliance with a target spectrum are quantified through a newly introduced index, δ _sv–sc , which aims to prioritize motions suites for response history analysis. To demonstrate the applicability of the procedure presented, the structural model of a multi-story building was subjected to numerous suites of motions that were highly ranked according to both the proposed approach (δ _sv–sc ) and the conventional one (δ _conv ), that is commonly used for earthquake records selection and scaling. The findings from numerous linear response history analyses reveal the superiority of the proposed multi-criterion approach, as it extensively reduces the intra-suite structural response variability and consequently, increases the reliability of the design values. The relation between the target reliability in assessing structural response and the size of the suite of motions selected was also investigated, further demonstrating the efficiency of the proposed selection procedure to achieve higher response reliability levels with smaller samples of ground motion.  相似文献   

Propagation of Elastic Compressional Waves in a Porous-Fractured Medium Saturated with Immiscible Fluids     

Markov  M. G.  Markova  I. A.  Jarillo  G. F. Ronquillo  Pervago  E. V. 《Izvestiya Physics of the Solid Earth》2020,56(3):357-363

Izvestiya, Physics of the Solid Earth - The problem of calculating the reflection and transmission coefficients of elastic P-wave incident from a porous half-space onto a fluid-filled crack is...  相似文献   

Sulfide Sulfur in Water Objects with Different Mineralization     

Fedorov  Yu. A.  Mikhailenko  A. V.  Dotsenko  I. V. 《Water Resources》2019,46(2):S59-S64

Water Resources - Hydrogen sulfide, like other sulfides, is formed in aquatic environments due to sulphate reduction processes and putrefactive decomposition of organic matter of bottom sediments,...  相似文献   

Thermal Bremsstrahlung of Local Sources Over Solar Spots Based on Microwave Observations     

Kaltman  T. I. 《Geomagnetism and Aeronomy》2019,59(8):1088-1095

Geomagnetism and Aeronomy - The paper presents the results of a study of microwave thermal bremsstrahlung of local sources above sunspots. Special attention is paid to the transition from thermal...  相似文献   

Solar System Collisions with Dense Interstellar Gas Clouds and Radiocarbon Traces of Periods with “Abnormally Low” Solar Modulation of Cosmic Rays     

Vasil’ev  G. I.  Konstantinov  A. N.  Kudryavtsev  I. V.  Ogurtsov  M. G.  Ostryakov  V. M.  Pavlov  A. K.  Frolov  D. A. 《Geomagnetism and Aeronomy》2019,59(8):1075-1080

Geomagnetism and Aeronomy - The causes of a sharp increase in the radiocarbon content in the Earth’s atmosphere for periods with abnormally low solar modulation of galactic cosmic rays (GCRs)...  相似文献