Deformation of partially molten granite: a review and comparison of experimental and natural case studies   总被引：4，自引：0，他引：4  

Claudio L. Rosenberg 《International Journal of Earth Sciences》2001,90(1):60-76

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Upper Palaeolithic faunas from south-west France. A zoogeographic perspective. Katherine V. Boyle. British Archaeological Reports International Series 557 1990 £27.00 ISBN 0 8654 704 3     

Louise H. van Wijngaarden-Bakker 《第四纪科学杂志》1991,6(3):259-260

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Spectrophotometric observations of a peculiar nitrogen-rich planetary nebula NGC 2440     

R. Louise 《Journal of Astrophysics and Astronomy》1982,3(2):145-150

By using the Boller and Chivens spectrograph with a moderate dispersion (59 å mm^-1) in the red spectral region, we obtained 65 spectra covering the whole surface of the planetary nebula NGC 2440. Intensities of Hα, [N II] λλ 6548–6584 and [S II] λλ 6717–6731 lines are derived using the IDS system available at the ESO in La Silva (Chile). The nebula is known to be a nitrogen-rich nebula (Peimbert 1978) surrounded by secondary structures (Minkowski 1964). The unusual high value of the [N II]/Hα in the central core (~ 30) is certainly due to the nitrogen overabundance occurring in that part of the nebula. Its variations from scale ionization structure (Capriotti, Cromwell and Williams 1971). The observations show clearly an outward increase of both [NII]/Hα andI(6717)/I(6713) ratios.  相似文献   

Report on the solar physics-plasma physics workshop     

P. A. Sturrock  P. J. Baum  J. M. Beckers  C. E. Newman  E. R. Priest  H. Rosenberg  D. F. Smith  D. G. Wentzel 《Solar physics》1976,46(2):411-431

This report summarizes the proceedings of a meeting held on 17–20 September 1974, at Stanford University. The purpose was to explore plasma physics problems which arise in the study of solar physics. Sessions were concerned with specific questions including the following: Is the solar plasma thermal or non-thermal? What spectroscopic data are required? What types of magnetic field structures exist? Do MHD instabilities occur? Do resistive or non-MHD instabilities occur? What mechanisms of particle acceleration have been proposed? What information do we have concerning shock waves? Very few questions were answered categorically but, for each question, there was discussion concerning the observational evidence, theoretical analyses, and existing or potential laboratory and numerical experiments.  相似文献   

On the limitations of geomagnetic measures of interplanetary magnetic polarity     

Russell  C. T.  Rosenberg  R. L. 《Solar physics》1974,37(1):251-256

Solar Physics - The maximum attainable accuracy in inferring the interplanetary magnetic polarity from polar cap magnetograms is about 88 %. This is achieved in practice, when high latitude polar...  相似文献   

Type III solar radio bursts and the fundamental-harmonic hypothesis     

Hans Rosenberg 《Solar physics》1975,42(1):247-257

The observational evidence is reviewed for the occurrence of type III solar radio bursts in pairs with frequency ratio two to one. We show that the observations can be explained under the hypothesis that there is a tendency for a type III burst to be followed by a second burst within approximately one second. This explanation leads to fewer difficulties than the hypothesis that type III bursts occur in pairs, one member being emitted at the fundamental of the local coronal plasma frequency, the other at its second harmonic. We conclude that in general, type III bursts are emitted at the second harmonic of the plasma frequency and that type III theories should account for this and only under very special circumstances (which are rare) for the emission at the fundamental and the second harmonic.  相似文献   

Determination of space and time sea wave structure from frequency characteristics of the radio signal scattered by the sea     

Leykin  I. Ostrovsky  I. Rosenberg  A. 《Oceanic Engineering, IEEE Journal of》1977,2(1):136-140

A method of determining sea-wave parameters from frequency characteristics of an RF signal scattered by the sea surface is considered. The method is based on the Doppler frequency shift due to orbital velocity of motion of long sea waves. It is shown that by measuring the frequency shift ofS-band signals scattered by a small (as compared to the sea-wave length) site on the sea surface, one is able to determine both integrated sea-wave parameters (e.g., rms waveheight and mean period) and the space-time structure of energy-carrying sea components. Results of field tests are presented substantiating the efficiency of the method and allowing measurement accuracy to be evaluated. The main systematic errors of the method are discussed.  相似文献   

Climate Change Impacts for the Conterminous USA: An Integrated Assessment     

Allison?M.?ThomsonEmail author  Norman?J.?Rosenberg  R.?Cesar?Izaurralde  Robert?A.?Brown 《Climatic change》2005,69(1):27-41

As carbon dioxide and other greenhouse gasses accumulate in the atmosphere and contribute to rising global temperatures, it is important to examine how a changing climate may affect natural and managed ecosystems. In this series of papers, we study the impacts of climate change on agriculture, water resources and natural ecosystems in the General Circulation Model (GCM)-derived climate change projections, described in Part 1, to drive the crop production and water resource models EPIC (Erosion Productivity Impact Calculator) and HUMUS (Hydrologic Unit Model of the United States). These models are described and validated in this paper using historical crop yields and streamflow data in the conterminous United States in order to establish their ability to accurately simulate historical crop and water conditions and their capability to simulate crop and water response to the extreme climate conditions predicted by GCMs. EPIC simulated grain and forage crop yields are compared with historical crop yields from the US Department of Agriculture (USDA) and with yields from agricultural experiments. EPIC crop yields correspond more closely with USDA historical county yields than with the higher yields from intensively managed agricultural experiments. The HUMUS model was validated by comparing the simulated water yield from each hydrologic basin with estimates of natural streamflow made by the US Geological Survey. This comparison shows that the model is able to reproduce significant observed relationships and capture major trends in water resources timing and distribution across the country.  相似文献   

Climate Change Impacts for the Conterminous USA: An Integrated Assessment     

Allison?M.?ThomsonEmail author  Norman?J.?Rosenberg  R.?Cesar?Izaurralde  Robert?A.?Brown 《Climatic change》2005,69(1):89-105

During this century global warming will lead to changes in global weather and climate, affecting many aspects of our environment. Agriculture is the sector of the United States economy most likely to be directly impacted by climatic changes. We have examined potential changes in dryland agriculture (Part 3) and in water resources necessary for crop production (Part 4) in response to a set of climate change scenarios. In this paper we assess to what extent, under these same scenarios, water supplies will be sufficient to meet the irrigation requirement of major grain crops in the US. In addition, we assess the overall impacts of changes in water supply on national grain production. We apply the 12 climate change scenarios described in Part 1 to the water resources and crop growth simulation models described in Part 2 for the conterminous United States. Drawing on data from Parts 3 and 4 we calculate what the aggregate national production would be in those regions in which grain crops are currently produced by applying irrigation where needed and water supplies allow. The total amount of irrigation water applied to crops declines under all climate change scenarios employed in this study. Under certain of the scenarios and in particular regions, precipitation decreases so much that water supplies are too limited; in other regions precipitation becomes so plentiful that little value is derived from irrigation. Nationwide grain crop production is greater when irrigation is applied as needed. Under irrigation, less corn and soybeans are produced under most of the climate change scenarios than is produced under baseline climate conditions. Winter wheat production under irrigation responds significantly to elevated atmospheric carbon dioxide concentrations [CO₂] and appears likely to increase under climate change.  相似文献   

Climate Change Impacts for the Conterminous USA: An Integrated Assessment     

Steven?J.?SmithEmail author  Allison?M.?Thomson  Norman?J.?Rosenberg  R.?Cesar?Izaurralde  Robert?A.?Brown  Tom?M.?L.?Wigley 《Climatic change》2005,69(1):7-25

As carbon dioxide and other greenhouse gases accumulate in the atmosphere and contribute to rising global temperatures, it is important to examine how derivative changes in climate may affect natural and managed ecosystems. In this series of papers, we study the impacts of climate change on agriculture, water resources and natural ecosystems in the conterminous United States using twelve scenarios derived from General Circulation Model (GCM) projections to drive biophysical impact models. These scenarios are described in this paper. The scenarios are first put into the context of recent work on climate-change by the IPCC for the 21st century and span two levels of global-mean temperature change and three sets of spatial patterns of change derived from GCM results. In addition, the effect of either the presence or absence of a CO₂ fertilization effect on vegetation is examined by using two levels of atmospheric CO₂ concentration as a proxy variable. Results from three GCM experiments were used to produce different regional patterns of climate change. The three regional patterns for the conterminous United States range from: an increase in temperature above the global-mean level along with a significant decline in precipitation; temperature increases in line with the global-mean with an average increase in precipitation; and, with a sulfate aerosol effect added to in the same model, temperature increases that are lower than the global-mean. The resulting set of scenarios span a wide range of potential climate changes and allows examination of the relative importance of global-mean temperature change, regional climate patterns, aerosol cooling, and CO₂ fertilization effects.  相似文献