Reindeer pastoralism in modern Siberia: research and survival during the time of crash   总被引：1，自引：0，他引：1  

Igor Krupnik 《Polar research》2000,19(1):49-56

In many areas across Siberia, the reindeer herding economy of the native people went into a deep recession during the post-Soviet transition of the 1990s. However, as a larger cross-section of data indicates, the reindeer stock decline is not a universal phenomenon. Nor is the present-day crisis in native Siberian herding economies an unprecedented event, as pastoralists did suffer tremendously in "traditional times", due to the devastating epizootics and other natural disasters, and even more so, during the Soviet-induceed collectivizsation. While such a historical review by no means diminishes the scale of the present-day crisis in native herding economies, it helps to identify both the experience and traditional adaptations once used by the native Siberians during the previous times of hardship. Of those, the most efficient were: maintaining cultural and ecological diversity in local herding systems; the ability to shift quickly between nomadic population as the invaluable source of cultural knowledge, technological expertise, and of domestic reindeer stock for ultimate recovery. The modern situation in Siberia, in fact, favours increased local diversity and helps to produce a steady stream of new "winners" as well as new "losers." This new experience has to be comprehensively documented, to produce both a reliable general overview and a detailed summary of the specific regional and local transitions.  相似文献   

A New Thermophoretic Precipitator for Off‐Line Particle Analysis     

Lucija Boskovic  Igor E. Agranovski 《洁净——土壤、空气、水》2012,40(6):565-570

A new thermophoretic particle precipitator has been developed for representative and efficient collection of aerosol particles from the ambient air and technological pipelines. The device consists of hot and cold plates (5 × 5 cm²) capable of operation at temperature gradients ranging from 20 000 to 100 000 K/m. A gas sample is made to pass through a 1‐mm slot between the plates at a flow rate of up to 1.5 L/min, which makes the device suitable for operation in conjunction with common aerosol instruments including DMA and diffusion batteries with similar operational flow rates. It was shown that the efficiency of the device was highest for the lowest gas flow rate used (0.3 L/min) reaching a level of above 99%. The efficiency was decreased reaching its minimal values at the highest flow rate investigated (1.5 L/min). However, even for highest flow rate, the average efficiency for removal of particle smaller than 60 nm was around 50%.  相似文献   

Atmospheric boundary layer over steep surface waves     

Yuliya Troitskaya  Daniil A. Sergeev  Oleg Druzhinin  Alexander A. Kandaurov  Olga S. Ermakova  Ekaterina V. Ezhova  Igor Esau  Sergej Zilitinkevich 《Ocean Dynamics》2014,64(8):1153-1161

Turbulent air-sea interactions coupled with the surface wave dynamics remain a challenging problem. The needs to include this kind of interaction into the coupled environmental, weather and climate models motivate the development of a simplified approximation of the complex and strongly nonlinear interaction processes. This study proposes a quasi-linear model of wind-wave coupling. It formulates the approach and derives the model equations. The model is verified through a set of laboratory (direct measurements of an airflow by the particle image velocimetry (PIV) technique) and numerical (a direct numerical simulation (DNS) technique) experiments. The experiments support the central model assumption that the flow velocity field averaged over an ensemble of turbulent fluctuations is smooth and does not demonstrate flow separation from the crests of the waves. The proposed quasi-linear model correctly recovers the measured characteristics of the turbulent boundary layer over the waved water surface.  相似文献   

Anisotropic elastic full‐waveform inversion of walkaway vertical seismic profiling data from the Arabian Gulf          下载免费PDF全文

John C Owusu  Marwan Charara  Scott Leaney  Allan Campbell  Shujaat Ali  Igor Borodin  Les Nutt  Henry Menkiti 《Geophysical Prospecting》2016,64(1):38-53

Borehole seismic addresses the need for high‐resolution images and elastic parameters of the subsurface. Full‐waveform inversion of vertical seismic profile data is a promising technology with the potential to recover quantitative information about elastic properties of the medium. Full‐waveform inversion has the capability to process the entire wavefield and to address the wave propagation effects contained in the borehole data—multi‐component measurements; anisotropic effects; compressional and shear waves; and transmitted, converted, and reflected waves and multiples. Full‐waveform inversion, therefore, has the potential to provide a more accurate result compared with conventional processing methods. We present a feasibility study with results of the application of high‐frequency (up to 60 Hz) anisotropic elastic full‐waveform inversion to a walkaway vertical seismic profile data from the Arabian Gulf. Full‐waveform inversion has reproduced the majority of the wave events and recovered a geologically plausible layered model with physically meaningful values of the medium.  相似文献   

Chilean Earthquakes: Aquifer Responses at the Russian Platform     

Alina Besedina  Evgeny Vinogradov  Ella Gorbunova  Igor Svintsov 《Pure and Applied Geophysics》2016,173(4):1039-1050

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Does Biot’s theory have predictive power?     

Igor A. Beresnev 《Pure and Applied Geophysics》2016,173(8):2671-2686

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First report of sablefish in spawning condition off the coast of Kamchatka and the Kuril Islands     

Orlov  Alexei M.; Biryukov  Igor A. 《ICES Journal of Marine Science》2005,62(5):1016-1020

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Geothermometers, Arrhenian behaviour and 'geothermometers'     

Igor M. Villa 《地学学报》2001,13(2):84-85

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Mikulino and Valdai palaeoenvironments in the Vologda area, NW Russia     

Valery Gey  Matti Saarnisto  Juha Pekka Lunkka  Igor Demidov 《Global and Planetary Change》2001,31(1-4)

Nine representative sediment sequences and pollen diagrams obtained during the Quaternary mapping programme carried out by the Geological Expedition (St. Petersburg, Russia) between 1960s and 1980s are presented from the Vologda area, NW Russian Plain, covering the time span from the Moscow cold (Saale) stage into the Late Valdai (Weichsel) substage. This work was done in order to shed light on the evolution of palaeoenvironments, vegetation and climate in the area. The results suggest that two major depressions in the Vologda area, namely the Mologa–Sheksnian and Prisukhonian basins, witnessed lake level fluctuations that were most likely closely linked to climatic fluctuations. It is suggested that during the Mikulino (Eem) thermal optimum most of the lowland areas were dry land. However, during the Early and Middle Valdai, the large depressions started to flood as a result of wet and cold climate. This caused the accumulation of lacustrine and also lacustrine–alluvial and lacustrine–bog sediments into the basins. The Valdai forest composition varied between closed spruce–birch forests and treeless tundra. Lakes persisted throughout the Valdai stage including the extremely dry last glacial maximum (LGM)-time when the Scandinavian Ice Sheet dammed the northbound rivers in the Vologda area.  相似文献   

Study of the outer galactic structure for 288°≤l≤310°, −7°≤b≤2°     

Silvia L. Garzoli  Igor F. Mirabel 《Astrophysics and Space Science》1973,25(1):207-216

The structure of the outer part of the Galaxy is studied, based upon 21-cm line observations of Hi in the region 288°l310°, –7°b2°.In this longitude range the galactic plane is strongly bend toward negative latitudes.The principal outer structure is a spiral arm which has a pitch angle of 10° and is formed by several concentrations differing in shape and size. There exists also a secondary concentration which could be a split from the previous structure.Possible hypotheses about the origin of the later feature are discussed.  相似文献