青海格尔木驼路沟喷流沉积型钴(金)矿床的黄铁矿Re-Os定年

青海驼路沟矿床是新近发现的中国西北首例独立大型喷流沉积型钴(金)矿床,赋矿岩石为富钠的热水沉积岩——石英钠长石岩。利用Re-Os同位素体系(ICP-MS方法)对不同类型矿石中的7件黄铁矿样品进行了定年,结果表明尽管它们的Re(0.122×10-9~8.988×10-9)和Os(0.00313×10-9~0.05366×10-9)的含量很低,但在两种相关图解上分别得到432±23Ma和442±17Ma较好等时线年龄。该Re-Os定年结果不仅进一步厘定区域纳赤台群地层的主体时代为早古生代,而且为确定东昆仑造山带晚奥陶世板块裂解及成矿作用提供了新的重要证据,对深入认识区域成矿规律和探讨地质构造演化具重要意义。     

Parallelization Load Balance Strategy for a Global Grid-Point Model

The Global/Regional Assimilation and PrEdiction System (GRAPES) is a new-generation operational numerical weather prediction (NWP) model developed by the China Meteorological Administration (CMA).It is a grid-point model with a code structure different from that of spectral models used in other operational NWP centers such as the European Centre for Medium-Range Weather Forecasts (ECMWF),National Centers for Environmental Prediction (NCEP),and Japan Meteorological Agency (JMA),especially in the context of p...     

On the DB gap of white dwarf evolution:effects of hydrogen mass fraction and convective overshooting

We investigate the spectral evolution of white dwarfs by considering the effects of hydrogen mass in the atmosphere and convective overshooting above the convection zone.Our numerical results show that white dwarfs with MH～10-16M⊙ show the DA spectral type between 46000■Teff■26000K and the DO or DB spectral type may appear on either side of this temperature range.White dwarfs with10-15M⊙ appear as DA stars until they cool to Teff～31000K;from then on they will evolve into DB white dwarfs as a result of conve...     

Magnetic activity of the spotted dwarf AP149 in the α Persei open cluster

The simultaneous photometric and spectroscopic observations of the spotted G dwarf AP149 in the young open cluster α Persei are analyzed here.We reconstruct the observed light curves with a two-starspot model by means of a light curve modeling technique,and find that the active regions shift oppositely along longitude on a time scale of one day.Combining with the observational data obtained by other groups,we discuss the evolution of spotted regions in the photosphere,and find that its starspots evolve not ...     

A binary study of color-magnitude diagrams of 12 globular clusters

Binary stars are common in star clusters and galaxies, but the detailed effects of binary evolution are not taken into account in some color-magnitude diagram (CMD) studies. This paper studies the CMDs of twelve globular clusters via binarystar stellar populations. The observational CMDs of the star clusters are compared to those of binary-star populations, and then the stellar metallicities, ages, distances and reddenings of these star clusters are obtained. The paper also tests the different effects of bi...     

多层湍流大气相位屏的数值模拟

高分辨图像重建技术可以有效消除湍流大气的影响,重建目标的接近望远镜衍射极限的图像。但是当目标的视场角比较大时,大气—望远镜综合系统不再是线性空不变的,给图像重建带来新的困难,它是大气性质中的一个重要特性,对大气相位屏的模拟应该满足这一特性。提出了一种可以模拟等晕区效应的多层大气相位屏的数值模拟方法,这种方法可以应用于等晕区对高分辨统计重建方法的影响的研究中。利用该数值模拟方法模拟了5″和8″的双星的斑点图,用斑点干涉术对模拟的双星进行了重建,并与实测的双星的斑点干涉术重建结果进行了比较。比较结果表明该数值模拟方法所产生的等晕区效应与实际的等晕区效应相似。     

行星际闪烁单站单频数据处理

太阳风是日地空间的主要物质来源,太阳风的观测对日地空间环境及地球物理的研究具有重要意义。地基行星际闪烁观测是监测太阳风风速,测量太阳风等离子体不规则结构,研究遥远致密射电源角径的重要且有效的方法。介绍了行星际闪烁地基观测的单站单频模式的基本理论,针对单站单频模式观测的数据处理及自编软件。本文的工作是为行星际闪烁单站双频系统数据分析处理作前期准备。     

SHRIMP U-Pb Dating of Zircons of a Dark Eclogite and aGarnet-bearing Gneissic Granitic Rock from Bixiling, EasternDabie Area, Anhui Province: Isotope Chronological Evidenceof Neoproterozoic UHP Metamorphism

The paper reports SHRIMP U-Pb zircon data of a dark eclogite and a post-eclogite garnet-bearing gneissic granitic rock from the Bixiling area, Yuexi County, Anhui Province, in the eastern Dabie Mountains. The eclogite, which is metamorphosed basic tuff, contains very scarce zircons in omphacite or garnet, but more zircons in quartz. They usually exhibit a double-layered texture, as shown clearly in cathodoluminescence images. Their inner main parts give a 206Pb/238U age of 757±7 Ma, representing the approximate age of the high-pressure (HP)- ultrahigh-pressure (UHP) metamorphic event during which the eclogite was formed. The outer peripheral parts of the zircons, which have been modified by late-stage fluids, give an age of 223±3 Ma. The granitic rock contains more zircons of anatectic origin found mostly in feldspar and quartz and usually also showing a similar composite texture. The inner main parts of the anatectic zircons with oscillatory zoning give a 206Pb/238U age of 727±15 Ma for the approxim     

WD+RG systems as the progenitors of type Ia supernovae

Type Ia supernovae(SNe Ia)play an important role in the study of cosmic evolution,especially in cosmology.There are several progenitor models for SNe Ia proposed in the past years.By considering the effect of accretion disk instability on the evolution of white dwarf(WD)binaries,we performed detailed binary evolution calculations for the WD+red-giant(RG)channel of SNe Ia,in which a carbon-oxygen WD accretes material from a RG star to increase its mass to the Chandrasekhar mass limit.According to these calcu...     

Possible distance indicators in gamma-ray pulsars

Distance measurement of gamma-ray pulsars is a current challenge in pulsar studies.The Large Area Telescope(LAT) aboard the Fermi gamma-ray observatory discovered more than 70 gamma-ray pulsars including 24 new gamma-selected pulsars with almost no distance information.We study the relation between gammaray emission efficiency(η=Lγ/E˙) and pulsar parameters for young radio-selected gamma-ray pulsars with known distance information in the first gamma-ray pulsar catalog reported by Fermi/LAT.We have introduce...