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61.
Marcos Villaverde Miguel Cerviño Valentina Luridiana 《Astrophysics and Space Science》2009,324(2-4):367-371
We show that sampling effects in the initial mass function are very important in the low-mass cluster case. To this aim, we compute photoionization models ionized by realistic clusters made up of various combinations of individual stars and clusters built with a synthesis model. We discuss the differences in the position on diagnostic diagrams, their implications, and future and ongoing applications of the present work. 相似文献
62.
欧洲中部的易北河流域是典型的湿润半湿润地区。夏季的水资源供给是限制农业生产的因素之一,特别是在具有较高农业生产力水平,而年降水量只有500 mm的黄土地区。通过总结气候变化与水文循环(GLOWA-Elbe)项目第一阶段的成果,根据气候和土地利用变化的各种情景并考虑其不确定性,对未来50 a德国易北河流域水资源供给稳定性作出综合评估。研究表明,欧洲中部必须从自然和社会角度应对未来气候变化情景下产生水资源供给短缺的可能情况。 相似文献
63.
Meng Ding Ya-Peng Zhang Yong-Jie Zhang Yuan-Peng Wang Tie-Kuang Dong Antonio De Benedittis Paolo Bernardini Fang Fang Yao Li Jie Liu Peng-Xiong Ma Zhi-Yu Sun Valentina Gallo Stefania Vitillo Zhao-Min Wang Yu-Hong Yu Chuan Yue Qiang Yuan Yong Zhou Yun-Long Zhang 《天文和天体物理学研究(英文版)》2019,(3):145-154
The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE. The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles. In this paper, a PSD on-orbit calibration procedure is described, which includes the five steps of pedestal, dynode correlation, response to minimum-ionizing particles, light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced. The detection efficiency of each PSD strip is verified to be above 99.5%; the total efficiency of the PSD for charged particles is above 99.99%. 相似文献
64.
65.
66.
Elena Gallo 《Astrophysics and Space Science》2007,311(1-3):161-165
With their relatively fast variability time-scales, Galactic X-ray binaries provide an excellent laboratory to explore the
physics of accretion and related phenomena, most notably outflows, over different regimes. After comparing the phenomenology
of jets in black hole systems to that of neutron stars, here I discuss the role of the jet at very low Eddington ratios, and
present preliminary results obtained by fitting the broadband spectral energy distribution of a quiescent black hole binary
with a ‘maximally jet-dominated’ model.
Chandra Fellow 相似文献
67.
68.
Valentina Vanghi Andrea Borsato Silvia Frisia Daryl L. Howard Gertruida Gloy John Hellstrom Petra Bajo 《Sedimentology》2019,66(7):2661-2685
Synchrotron high‐resolution and micro‐X‐ray fluorescence elemental mapping of two coeval coralloid speleothems from Lamalunga Cave (Italy) are complemented with petrographic, morphological and microstratigraphic studies. The importance of these speleothems relies on their direct and indirect association with a complete Neanderthal skeleton (‘Altamura Man’) found inside the cave. The coralloids grew discontinuously between 64·6 ka and the Holocene and reveal exceptionally high concentrations of Mg, Sr and Si, particularly on convex surfaces, where evaporation is more intense. The incorporation of trace elements depends on several factors including location, shape and geometrical evolution during their growth, as well as climate and environmental parameters. This resulted in calcite precipitation with Sr compositions from 100 to 1200 ppm and an average concentration of 7000 ppm Mg. An unusually high Si content (up to 16%) is possibly derived from volcanic ash transported as particulate and in solution inside the cave. The most common fabrics observed consist of non‐fluorescent elongated columnar calcite forming clean isopachous bands and fluorescent fibre‐like crystals associated with laminated, lenticular bands high in Sr, Mg and Si. Variability in Sr, Mg and Si concentrations appears to induce fabric changes in the coralloids. Elongation and lattice distortion of the crystals was found to coincide with high Mg concentrations. The transition from compact elongated to open to fibre‐like, is here interpreted as due to high concentrations of Si and Sr, which are preferentially incorporated in the speleothem at crystal boundaries and intra‐laminae. It is here inferred that coralloid fabric changes and their elemental content potentially record local rainfall variations through time, with the clean compact calcite marking high infiltration and open fibre‐like and micrite fabrics recording dry periods. 相似文献
69.
The transition in the Slovenian countryside is examined through a case study of Cirkovce, a local centre for the central southern
section of the Dravsko polje plain where natural and socio-geographical factors underpin a mixed rural-urban structure. Farming
is intensive, but a high percentage of people are now employed outside agriculture; a situation which is reflected clearly
in the appearance of the settlement. The process of rural depopulation, balanced by the growth of employment in industry and
services, is reflected in a secondary knot of settlement around Cirkovce's railway station. Agriculture is still very significant
but there needs to be some consolidation of landholding to create larger units suitable for market production and food processing.
But the village must also improve its range of functions and provide a better environment for the non-agricultural population
which will become increasing important for its future development.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献