Semantically based reclassification of Danish land-use and land-cover information     

Martin Rudbeck Jepsen  Gregor Levin 《International journal of geographical information science》2013,27(12):2375-2390

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Removal of Phenol by Immobilization of Trametes versicolor in Silica–Alginate–Fungus Biocomposites and Loofa Sponge          下载免费PDF全文

Maira Carabajal  Mercedes Perullini  Matias Jobbágy  René Ullrich  Martin Hofrichter  Laura Levin 《洁净——土壤、空气、水》2016,44(2):180-188

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Contemporary crustal movements (CCMs) in Kamchatka     

V. E. Levin  V. F. Bakhtiarov  N. N. Titkov  S. S. Serovetnikov  M. A. Magus’kin  A. V. Lander 《Izvestiya Physics of the Solid Earth》2014,50(6):732-751

The works on geodetic monitoring of the contemporary crustal motions (CCMs) in the region of the Kamchatka Peninsula and Komandor Islands for the 40-year history of instrumental observations are reviewed. The examples of CCM recording by the classical geodetic methods and, since 1996, by the Global Positioning System (GPS) are presented. The deployment of the regional network for GNSS observations by the Kamchatka Branch of the Geophysical Survey of the Russian Academy of Sciences (KAMNET) made it possible to study the geodynamical processes at the junction of three major plates (Eurasian, North American, and Pacific) and smaller plates (Okhotsk and Bering). The interpretation of the examples of recorded CCMs is presented. The prospects of further development in the field of studying the geodynamics of the Koryak-Kamchatka region are outlined.  相似文献   

Seasonal surface ocean circulation and dynamics in the Philippine Archipelago region during 2004–2008     

Weiqing Han  Andrew M. Moore  Julia Levin  Bin Zhang  Hernan G. Arango  Enrique Curchitser  Emanuele Di Lorenzo  Arnold L. Gordon  Jialin Lin 《Dynamics of Atmospheres and Oceans》2009,47(1-3):114-137

The dynamics of the seasonal surface circulation in the Philippine Archipelago (117°E–128°E, 0°N–14°N) are investigated using a high-resolution configuration of the Regional Ocean Modeling System (ROMS) for the period of January 2004–March 2008. Three experiments were performed to estimate the relative importance of local, remote and tidal forcing. On the annual mean, the circulation in the Sulu Sea shows inflow from the South China Sea at the Mindoro and Balabac Straits, outflow into the Sulawesi Sea at the Sibutu Passage, and cyclonic circulation in the southern basin. A strong jet with a maximum speed exceeding 100 cm s⁻¹ forms in the northeast Sulu Sea where currents from the Mindoro and Tablas Straits converge. Within the Archipelago, strong westward currents in the Bohol Sea carry the surface water of the western Pacific (WP) from the Surigao Strait into the Sulu Sea via the Dipolog Strait. In the Sibuyan Sea, currents flow westward, which carry the surface water from the WP near the San Bernardino Strait into the Sulu Sea via the Tablas Strait.These surface currents exhibit strong variations or reversals from winter to summer. The cyclonic (anticyclonic) circulation during winter (summer) in the Sulu Sea and seasonally reversing currents within the Archipelago region during the peak of the winter (summer) monsoon result mainly from local wind forcing, while remote forcing dominates the current variations at the Mindoro Strait, western Sulu Sea and Sibutu passage before the monsoons reach their peaks. The temporal variations (with the mean removed), also referred to as anomalies, of volume transports in the upper 40 m at eight major Straits are caused predominantly by remote forcing, although local forcing can be large during sometime of a year. For example, at the Mindoro Strait, the correlation between the time series of transport anomalies due to total forcing (local, remote and tides) and that due only to the remote forcing is 0.81 above 95% significance, comparing to the correlation of 0.64 between the total and local forcing. Similarly, at the Sibutu Passage, the correlation is 0.96 for total versus remote effects, comparing to 0.53 for total versus local forcing. The standard deviations of transports from the total, remote and local effects are 0.59 Sv, 0.50 Sv, and 0.36 Sv, respectively, at the Mindoro Strait; and 1.21 Sv, 1.13 Sv, and 0.59 Sv at the Sibutu Passage. Nonlinear rectification of tides reduces the mean westward transports at the Surigao, San Bernardino and Dipolog Straits, and it also has non-negligible influence on the seasonal circulation in the Sulu Sea.  相似文献   

Rassvet: Backward Monte Carlo radiative transfer in spherical-shell planetary atmospheres     

Sergey L. Gratiy  Deborah A. Levin 《Icarus》2010,206(1):366-2499

Validation of global numerical models of planetary atmospheres requires simulating images and spectra from the IR to UV spectral regions in order to compare them with remote observations. This paper describes Rassvet, a 3-D spherical-shell backward Monte Carlo radiative transfer model developed for such simulations. It utilizes a new methodology for calculating atmospheric brightness in scattered sunlight by introducing the concept of an “effective emission source”. This allows for the accumulation of the scattered contribution along the entire path of a ray and the calculation of the atmospheric radiation when both scattered sunlight and thermal emission contribute to the remote measurement - which was not possible in previous models. A “polychromatic” algorithm is extended for applications with the backward Monte Carlo method and implemented in the model. It allows for the calculation of radiative intensity for several wavelengths simultaneously, resulting in improved efficiency. The capabilities of the model are demonstrated by simulating remote measurements from the atmosphere of Io.  相似文献   

Isotopic-geochemical features and age of zircons in dunites of the platinum-bearing type Uralian massifs: Petrogenetic implications     

G. B. Fershtater  A. A. Krasnobaev  F. Bea  P. Montero  V. Ya. Levin  V. V. Kholodnov 《Petrology》2009,17(5):503-520

This paper presents results of isotopic (Cameca IMS1270 NORDSIM and SHRIMP-II ion microprobes) and geochemical (LA-ICP MS) study of zircons in three dunite samples of the Uralian-Alaskan-type massifs of the Urals: Kosva, Sakharin, and Eastern Khabarny. The zircons in the dunites share common features. Each sample contains the following genetic and age groups of zircons: (1) xenogenic zircons of the Archean and Proterozoic age; (2) zircons of magmatic appearance, which in age and geochemistry are close to the zircons from associated gabbroids; (3) postmagmatic zircons that presumably crystallized from hydrothermal solutions. The xenogenic zircons of the Archean age in each of three samples comprise transparent fragments, which are depleted in U and other trace elements and presumably have mantle origin. Xenogenic zircons of the Proterozoic age (1500–2000 Ma) occur as oval grains with surface abrasion, the traces of their redeposition. The geochemical features of the xenogenic zircons unequivocally demonstrate their affiliation to the continental crust—the basement of the Uralian orogen. The zircons of magmatic habit in all the dunite samples are close in age to the associated gabbroids: 435–432 Ma in the Kosva Massif, 378–374 in the Sakharin Massif, and 407–402 Ma in the Eastern Khabarny Massif, and mark the age of dunite formation. In addition, the magmatic zircons from dunites and associated gabbroids share similar geochemical features. These data could serve as additional argument in support of cumulate origin of dunites in the Uralian-Alaskan-type complexes. The postmagmatic zircons are most enriched in trace elements and were presumably formed from a fluid phase, which was responsible for the recrystallization of dunites and redistribution of Cr-spinel and PGE mineralization.  相似文献   

Depth distribution of earthquakes through latitudinal belts of the Pacific region: General trends     

B. W. Levin  E. V. Sasorova 《Doklady Earth Sciences》2009,426(1):699-704

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Attenuation of Gravity Waves in Fast Ice     

Levin  B. V.  Kovalev  P. D.  Kovalev  D. P.  Kirillov  K. V. 《Doklady Earth Sciences》2019,484(2):177-180

Doklady Earth Sciences - The attenuation coefficients of sea waves in ice in the coastal zone of the Sea of Okhotsk with periods from 4 to 30 s were estimated as a function of their wavelength...  相似文献   

The coalescence of water drops I. A theoretical model of approaching drops     

Nitza Arbel  Zev Levin 《Pure and Applied Geophysics》1977,115(4):869-893

The approach of two water drops in the absence of air flow around them is theoretically investigated. By assuming deformation criteria it is possible to solve the equation of motion of the drops under the influence of a variety of forces. These forces include the viscous force exerted by the air between the two deformed surfaces, the London-Van Der Waals forces and the force of gravity. It is found that the viscous forces dominate over the whole distance of the interaction. The equations have analytical solutions when a head-on approach is considered and when the deformation of the drops is assumed constant during the interaction. The equations were solved numerically for other deformation criteria and for non head-on approaches.The results of the present model are used in the following paper to compute the coalescence efficiencies of water drops. The model is primarily applicable to situations in which the large drop is stationary and the small one approaches it from below. However, it could also be used for interaction between freely falling drops as long as their relative velocities exceed about 13 cm/sec.Appendix: List of symbols C constant of the motion - D distance between the deformed surfaces of the drops - D _o initial value ofD - D _m the value at which the viscous force is maximum - D _N normalized distance - D _s the distance at which the velocity of approach vanishes - F _c centrifugal force - F _g force due to gravity - F _N normalized viscous force - F _LV force due to London-Van der Waals effect - F _R radial component of the force - F _V viscous force - F _t tangential component of the force - g acceleration due to gravity - M _L mass of large drop - m _s mass of small drop - p ratio of radii of interacting drops - R radius of an arbitrary drop - r distance between the centers of mass of the two drops - R _D radius of deformation - R _L radius of larger drop - R _s radius of smaller drop - t time - u defined in equation 20 — has the meaning of kinetic energy - v relative velocity of the deformed surfaces - v ₀ initial value ofv - V ₀ initial relative velocity of the centers of the drops - V _c critical impact velocity - V _i impact velocity - V _N ,v _n normalized velocity - V _t tangential component of the velocity - W _i velocity of the small drop at infinity for it to reach the pointD ₀ at velocityV ₀ - x instantaneous impact distance -  average critical impact distance for coalescence - x ₀ initial value of the impact distance - x _c critical impact distance for coalescence - coefficient of deformation - _i impact angle according toWhelpdale andList (1971) - coefficient of deformation - viscosity - surface tension - F _s sum of forces acting on the small drop - F _L sum of forces acting on the large drop - time constant - _R Rayleigh's oscillation period On sabbatical leave (1976–77) from the Department of Geophysics and Planetary Sciences, Tel Aviv University, Ramat Aviv, Israel.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

Effects of long-range transport on atmospheric trace constituents at the baseline station tenerife (Canary Islands)     

Rainer Schmitt  Barbara Schreiber  Ingeborg Levin 《Journal of Atmospheric Chemistry》1988,7(4):335-351

First results of baseline observations from the new BAPMoN station Tenerife give information about the atmospheric background in this latitude of about 25° N in the North Atlantic. The influence of the meridional exchange with the northern part of the hemisphere as well as transport from the African continent is evident. Changes of air mass are strongly reflected in the concentration records of carbon dioxide, methane, and ozone depending on the seasonal and meridional distribution of these components. Transport of Sahara dust results in an increase of optical thickness and an ozone depletion. According to the seasonal frequency of characteristic transport conditions, these influences are reflected in the annual cycle of the records.  相似文献