Infiltration processes and flow rates in developed karst vadose zone using tracers in cave drips   总被引：1，自引：0，他引：1  

Youval Arbel  Noam Greenbaum  Jens Lange  Moshe Inbar 《地球表面变化过程与地形》2010,35(14):1682-1693

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Nitrogen deficiency, phosphorus sufficiency, and the invasion of Lake Kinneret, Israel, by the N2-fixing cyanobacterium Aphanizomenon ovalisporum     

Moshe Gophen  Val H. Smith  Aminadav Nishri  Stephen T. Threlkeld 《Aquatic Sciences - Research Across Boundaries》1999,61(4):293-306

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Image enhancement by multi‐parameter characterization of common image gathers     

Moshe Reshef 《Geophysical Prospecting》2014,62(6):1453-1467

We present an innovative approach for seismic image enhancement using multi‐parameter angle‐domain characterization of common image gathers. A special subsurface angle‐domain imaging system is used to generate the multi‐parameter common image gathers in a summation‐free image space. The imaged data associated with each common image gathers depth point contain direction‐dependent opening‐angle image contributions from all the available incident and scattered wave‐pairs at this point. Each direction‐dependent opening‐angle data can be differently weighted according to its coherency measure. Once the optimal migration velocity is used, it is assumed that in the actual specular direction, the coherency measure (semblance) along reflection events, from all available opening angles and opening azimuths, is larger than that along non‐specular directions. The computed direction‐dependent semblance attribute is designed to operate as an imaging filter which enhances specular migration contributions and suppresses all others in the final migration image. The ability to analyse the structural properties of the image points by the multi‐parameter common image gather allows us to better handle cases of complicated wave propagation and to improve the image quality at poorly illuminated regions or near complex structures. The proposed method and some of its practical benefits are demonstrated through detailed analysis of synthetic and real data examples.  相似文献   

Trends in CO2 emissions in Israel—an international perspective     

Moshe Yanai  Jean Koch  Uri Dayan 《Climatic change》2010,101(3-4):555-563

As a Party to the United Nations Framework Convention on Climate Change, Israel conducts a periodical inventory of greenhouse gases emissions. These data allowed the generation of time series of CO₂ emissions per capita and per GDP for the period 1990–2004. It was found that CO₂ emissions per capita increased dramatically from 1990 to 2000, reflecting the rapid economic growth that was initiated by the massive immigration wave at the beginning of the nineties. These emissions remained stable between 2000 and 2004, reflecting the economic stagnation caused by the uprising in the Palestinian Territories, as well as stagnation in the global economy. CO₂ emissions per GDP (CO₂ intensity) remained stable along the whole reviewed period. This stability can be explained by a shift in electricity consumption from the industrial sector towards the commercial and the residential sectors, corresponding to an increase in the standard of living in the same period. A comparison was held with countries considered as developed for many years represented by the five largest economies (G-5) and recently developed countries (RDCs). Although Israel exhibits emission levels within the range of the G-5 countries, it does not fit the patterns demonstrated by these countries. Trends observed in Israel resemble these observed in other RDCs, such as Spain or Greece, confirming the classification of Israel in this category.  相似文献   

Remarks on two papers dealing with the response of beams on two-parameter elastic foundations     

Moshe Eisenberger  Jacobo Bielak 《地震工程与结构动力学》1989,18(7):1077-1078

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A Thin Ring Model for the Oh Megamaser in Iiizw35     

Rodrigo Parra  John Conway  Moshe Elitzur 《Astrophysics and Space Science》2005,295(1-2):325-330

We present a model for the OH megamaser emission in the starburst galaxy IIIZw35. The observed diffuse and compact OH maser components in this source are explained by a single phase of unsaturated clumpy gas distributed in a thin ring structure and amplifying background continuum. We emphasize the importance of clumpiness in the OH masing medium, an effect that has not been fully appreciated previously.The model explains why multiple bright spots are seen only at the ring tangents while smoother emission is found elsewhere. Both the observed velocity gradients and the line to continuum ratios around the ring enquire a geometry where most of the seed photons come from a continuum emission which lies outside the OH ring. To explain both the OH and continuum brightness, free-free absorbing gas is required along the ring axis to partially absorb the far side of the ring. It is proposed that the required geometry arises from an inwardly propagating ring of starburst activity.  相似文献   

Discs and haloes in pre-main-sequence stars     

Dejan Vinkovi&#;  &#;eljko Ivezi&#;  Anatoly S. Miroshnichenko  Moshe Elitzur 《Monthly notices of the Royal Astronomical Society》2003,346(4):1151-1161

We study the infrared (IR) emission from flared discs with and without additional optically thin haloes. Flux calculations of a flared disc in vacuum can be considered a special case of the more general family of models in which the disc is imbedded in an optically thin halo. In the absence of such a halo, flux measurements can never rule out its existence because the disc flaring surface defines a mathematically equivalent halo that produces the exact same flux at all IR wavelengths. When a flared disc with height H at its outer radius R is imbedded in a halo whose optical depth at visual wavelengths is  τ_halo  , the system IR flux is dominated by the halo whenever  τ_halo > (1/4) H / R   . Even when its optical depth is much smaller, the halo can still have a significant effect on the disc temperature profile. Imaging is the only way to rule out the existence of a potential halo, and we identify a decisive test that extracts a signature unique to flared discs from imaging observations.  相似文献   

Geological and pedological aspects of an Early-Paleolithic site: Revadim,Central Coastal Plain,Israel     

Gdaliahu Gvirtzman  Moshe Wieder  Ofer Marder  Hamudi Khalaily  Rivka Rabinovich  Hagai Ron 《Geoarchaeology》1999,14(2):101-126

An Early Paleolithic site was recently discovered within a sequence of paleosols in the Revadim Quarry, central coastal plain of Israel. The section is composed of three superimposed soils in a continuous sequence, but separated by two unconformity surfaces. The uppermost paleosol is a modern Dark Brown Grumusol (Vertisol), the middle is a Quartzic Gray Brown Soil (Haploxeralf), and the lower is a Red Hamra (Rhodoxeralf). Normal magnetic polarity was detected in the two lower soils, indicating that they are younger than the Brunhes–Matuyama boundary (<780 ka). A human occupation bed, enriched in secondary carbonate nodules, forms the lower part of the Quartzic Gray Brown Soil and overlies the Red Hamra. The living floor is located on top of the unconformity surface, separating the Red Hamra from the overlying Quartzic Gray Brown Soil. Middle to Late Acheulian handaxes, choppers, cores, and flake tools, including tools made by the Levallois technique, and man-laid flint pebbles were excavated in the human occupation bed. In addition, two elephant tusks, an elephant pelvis, an elephant tooth (Palaeoloxodon antiquus), tusk splinters, and bones of equid, suid, cervid, bovid, felid, and rodents were also collected. Based on well-documented nearby boreholes and on regional correlation, it appears that the underlying dune sands, the parent materials from which the Red Hamra developed, were deposited probably during a phase of high-stand sea level of Isotope Stage 9. The Red Hamra developed simultaneously with the human occupation of the site, probably during a phase of low-stand sea-level of Isotope Stage 8, before some 300–245 ka. The overlying dune sands, the parent materials from which the Quartzic Gray Brown Soil developed, were deposited probably during a phase of high-stand sea level of Isotope Stage 7. The climate prevailing in the area during Stage 8, as well as during the human habitation, was moist, with a dense vegetation cover of grassland and probably scattered trees. A small lake of trapped fresh water at a junction of two small tributaries of the Soreq River drainage system near the area occupied was available to hominids and animals. © 1999 John Wiley & Sons, Inc.  相似文献   

A simplified analytical method for soil penetration analysis     

David Z. Yankelevsky  Moshe A. Adin 《国际地质力学数值与分析法杂志》1980,4(3):233-254

A new one-dimensional model for penetration analysis of a rigid projectile into a soil target is presented. The soil medium is represented by a set of discs of constant thickness, responding in the radial direction under plain strain regime. When penetration through a typical disc occurs, the projectile displaces soil material and a radial plastic shock wave propagates in the disc. The interaction pressure between the projectile and soil material is compatible with the motion of the contact boundary, between them. The instantaneous resistive force is obtained by summation of the contributions of all the discs which are in contact with the nose surface of the projectile. Soil is considered as a ‘floating’ ideally locking material, in which the locking volumetric strain is adjusted to the physical stress–strain properties of the soil material. Friction between projectile and soil is assumed to be negligible. Comparison is made with both twodimensional computer program results and experimental data, and very good agreement is observed. Comparison with other analytical methods reveals that the present model most closely resembles existing experimental results and permits further analysis of the problem as predictions of target response and of stress distribution on the projectile nose. The calculations require very small amounts of computer time. Analysis with the present model yields an efficient and comprehensive means to analyse penetration and perform parameter analysis.  相似文献   

Application of real-time PCR for quantitative determination of hepatic vitellogenin transcript levels in the striped sea bream, Lithognathus mormyrus     

Bruria Funkenstein  Anna Dyman  Berta Levavi-Sivan  Moshe Tom 《Marine environmental research》2004,58(2-5):659

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