Intermediate-age open clusters: Collinder 110     

Angela Bragaglia  Monica Tosi 《Monthly notices of the Royal Astronomical Society》2003,343(1):306-312

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桂西古侵蚀沉积间断面型金矿床(续载)     

陈开礼 《南方国土资源》2001,14(1):37-40

古侵蚀沉积间断面型金矿是桂西的主要金矿床类型。文章着重分析该类型金矿成矿地质条件 ,论述矿床成因及成矿机理 ,认为此类型金矿易采易冶 ,经济效益显著 ,建议加大开发力度。  相似文献   

Transforming observational data and theoretical isochrones into the ACS/WFC Vega-mag system     

Luigi R. Bedin †  Santi Cassisi  Fiorella Castelli  Giampaolo Piotto  Jay Anderson  Maurizio Salaris  Yazan Momany  Adriano Pietrinferni 《Monthly notices of the Royal Astronomical Society》2005,357(3):1038-1048

We propose a zero-point photometric calibration of the data from the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) on board the Hubble Space Telescope , based on a spectrum of Vega and the most up-to-date in-flight transmission curves of the camera. This calibration is accurate at the level of a few hundredths of a magnitude. The main purpose of this effort is to transform the entire set of evolutionary models into a simple observational photometric system for ACS/WFC data, and to make them available to the astronomical community. We provide the zero-points for the most used ACS/WFC bands, and give basic recipes for calibrating both the observed data and the models. We also present the colour–magnitude diagram from ACS data of five Galactic globular clusters, spanning the metallicity range  −2.2 <[Fe/H] < −0.04  , and we provide fiducial points representing their sequences from several magnitudes below the turn-off to the red giant branch tip. The observed sequences are compared with the models in the newly defined photometric system.  相似文献   

Short-term Climate Characteristics at Ny-(A)lesund over the Arctic Tundra Area     

Deng Haibin  Lu Longhua  Bian Lingen 《极地研究(英文版)》2005,16(2)

Based on the Germany Koldwey Station's 1994-2003 conventional observation hourly data, this paper conducts a statistical analysis on the short-term climate characteristics for an arctic tundra region (Ny-(A)lesund island) where our first arctic expedition station (Huanghe Station) was located. Affected by the North Atlantic warming current, this area has a humid temperate climate, and the air temperature at Ny-(A)lesund rose above 0 ℃ even during deep winter season during our research period. The wind speed in this area was low and appeared most at southeast direction. We find that the temperature at Ny-(A)lesund rose in the faster rate (0.68 ℃/10 a) than those at the whole Arctic area. Compared with the floating ices where our expedition conducted in the Arctic, Ny-(A)lesund was warmer and more humid and had lower wind speed. Comparison of the near surface air temperature derived by NCEP/NCAR reanalysis to the conventional measurements conducted at the Koldwey site in Ny-(A)lesund area shows a good agreement for winter season and a significant difference for summer season.  相似文献   

Galileo系统及其在中国的应用   总被引：9，自引：0，他引：9  

韩玲  朱文耀 《天文学进展》2005,23(1):10-28

较详细地介绍了Galileo系统的全面体系结构、频率设计、服务内容及其广泛的应用范围，指出了它与GPS系统相比的优点，并对开发和增强Galileo系统在我国多层次、全方位的应用提出了建议。  相似文献   

The old open clusters Saurer A, B and C revisited     

Giovanni Carraro  Gustavo Baume 《Monthly notices of the Royal Astronomical Society》2003,346(1):18-26

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黄金的成色     

刘儒 《吉林地质》1994,13(3):81-83,45

黄金的成色并不是一成不变的，它成色的高低是与成矿温度、成矿阶段、深度、时代、变质程度、水溶液及风化作用等有一定关系，我们从这些关系中可以寻找到我们找矿的捷径和依据。  相似文献   

A multicolour CCD photometric study of the open clusters NGC 2866, Pismis 19, Westerlund 2, ESO96-SC04, NGC 5617 and NGC 6204     

Giovanni Carraro  Ulisse Munari 《Monthly notices of the Royal Astronomical Society》2004,347(2):625-631

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Fast iterative solution of large undrained soil‐structure interaction problems     

Kok‐Kwang Phoon  Swee‐Huat Chan  Kim‐Chuan Toh  Fook‐Hou Lee 《国际地质力学数值与分析法杂志》2003,27(3):159-181

In view of rapid developments in iterative solvers, it is timely to re‐examine the merits of using mixed formulation for incompressible problems. This paper presents extensive numerical studies to compare the accuracy of undrained solutions resulting from the standard displacement formulation with a penalty term and the two‐field mixed formulation. The standard displacement and two‐field mixed formulations are solved using both direct and iterative approaches to assess if it is cost‐effective to achieve more accurate solutions. Numerical studies of a simple footing problem show that the mixed formulation is able to solve the incompressible problem ‘exactly’, does not create pressure and stress instabilities, and obviate the need for an ad hoc penalty number. In addition, for large‐scale problems where it is not possible to perform direct solutions entirely within available random access memory, it turns out that the larger system of equations from mixed formulation also can be solved much more efficiently than the smaller system of equations arising from standard formulation by using the symmetric quasi‐minimal residual (SQMR) method with the generalized Jacobi (GJ) preconditioner. Iterative solution by SQMR with GJ preconditioning also is more elegant, faster, and more accurate than the popular Uzawa method. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Impersonal parameters from Hertzsprung–Russell diagrams     

R. E. Wilson  Jarrod R. Hurley 《Monthly notices of the Royal Astronomical Society》2003,344(4):1175-1186

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