东准噶尔双泉金矿LA-ICP-MS锆石U-Pb测年及赋矿岩石地球化学特征

为了解双泉金矿成矿时代及成矿环境,分别对双泉金矿含金石英脉和赋矿岩石进行采样测试分析。高精度LA-ICP-MS锆石U-Pb法测年结果表明,双泉金矿含金石英脉加权平均206Pb/238U年龄为(303.53±0.79)Ma,代表了含金石英脉形成年龄,属晚石炭世前后挤压推覆构造体系产物。与双泉金矿主成矿期年龄对比,结合矿区成矿条件及黄铁矿、毒砂等矿物形态特征,认为该金矿的形成不是一期结果,而是经历了预富集、富集的演化历程。赋矿岩石地球化学分析结果表明,岩石的SiO2、K2O、CaO(SiO2=58.82%~89.25%,K2O=1.12%~4.47%,CaO=0.52%~4.47%)含量高,Na2O含量低(Na2O=0.43%~1.76%),A/CNK值大于1,δ值小于3.3,属过铝质、钙碱性岩石,具富钾钙、贫钠镁特点;Ba相对Rb,Th亏损,K2O含量接近活动陆缘K2O含量,TiO2含量与岛弧TiO2含量接近,推断岩体形成于活动陆缘或岛弧环境;稀土元素具弱的负Eu、负Ce异常,(La/Sm)N值较(Gd/Yb)N值大,轻稀土元素分馏程度高于重稀土元素,表明岩浆具壳幔混熔特点。东准噶尔后碰撞阶段早石炭世至二叠纪晚期发生的陆-陆碰撞造山及伸展张弛构造运动可能是造成此结果的主要构造因素。     

印度尼西亚内格拉萨金矿床地质特征与找矿潜力

印度尼西亚内格拉萨金矿位于巽他—班达岛弧带中部的西爪哇岛,矿区内发育多条含金矿脉。根据矿区金矿脉的地质特征、矿石特征和围岩蚀变特征,研究了矿石成分、成矿温度、成矿流体、成矿年代和成矿模式,分析了找矿潜力。研究表明,矿区的主要矿体还未被剥蚀,深部可能存在规模更大、品位更高的金矿脉,甚至存在斑岩型铜金矿。     

The intensified impact of El Niño on late-summer precipitation over East Asia since the early 1990s

Climate Dynamics - This study reveals a pronounced enhancement of the relationship between the winter El Niño and the following late-summer precipitation over East Asia since the early 1990s....     

6月MJO对广东降水调制与直接影响系统的联系

利用1979—2008年广东省86个测站逐日降水资料及NCEP-DOE第2套分析资料等,提出影响广东500 hPa环流系统的判别方法,分析6月赤道MJO (季节内振荡) 活动对广东降水的调制作用随中低纬度环流型的变化。结果表明:强MJO第3位相广东出现强降水的概率最高,是8个位相中唯一强降水等级出现日数超过弱降水日数的位相。在直接影响广东的5种500 hPa环流系统 (包括西风槽、西风浅槽、平直西风或高压边缘、副热带高压、热带低压槽) 中,西风槽类型影响时,赤道MJO对广东降水的调制作用最强,其他环流类型影响时,MJO的调制作用很弱。广东在西风槽影响下,当处于MJO第3位相 (第6位相) 时,降水距平百分率达到最高 (低)。MJO对广东降水的调制作用随中低纬度环流系统的变化,主要是环流系统之间的不同配合导致降水所需的动力上升条件和水汽输送条件的相互配合发生变化造成的。     

Analysis of the potential field and equilibrium points of irregular-shaped minor celestial bodies

The equilibrium points of the gravitational potential field of minor celestial bodies, including asteroids, comets, and irregular satellites of planets, are studied. In order to understand better the orbital dynamics of massless particles moving near celestial minor bodies and their internal structure, both internal and external equilibrium points of the potential field of the body are analyzed. In this paper, the location and stability of the equilibrium points of 23 minor celestial bodies are presented. In addition, the contour plots of the gravitational effective potential of these minor bodies are used to point out the differences between them. Furthermore, stability and topological classifications of equilibrium points are discussed, which clearly illustrate the topological structure near the equilibrium points and help to have an insight into the orbital dynamics around the irregular-shaped minor celestial bodies. The results obtained here show that there is at least one equilibrium point in the potential field of a minor celestial body, and the number of equilibrium points could be one, five, seven, and nine, which are all odd integers. It is found that for some irregular-shaped celestial bodies, there are more than four equilibrium points outside the bodies while for some others there are no external equilibrium points. If a celestial body has one equilibrium point inside the body, this one is more likely linearly stable.     

Calibration of the Soho/Lasco C3 White Light Coronagraph

We present a detailed review of the calibration of the LASCO C3 coronagraph on the SOHO satellite. Most of the calibration has been in place since early in the mission and has been utilized to varying degrees as required by specific analysis efforts. However, using observational data from the nearly decade-long database of LASCO images, we have re-evaluated and improved many aspects of the calibration. This includes the photometric calibration, vignetting function, geometric distortion, stray light, and exposure and observation times. Using this comprehensive set of corrections we have generated and made available a set of calibrated coronal images along with a set of periodic background images to ease the accessibility and use of the LASCO database. Deceased     

Determination of copper complexation in surface microlayer of Daya Bay and Jiaozhou Bay

1 INTRODUCTION Bioavailability to the biota and the biogeo-chemistry of trace metals in marine environment areaffected by their chemical speciation in the naturalsystem (Bruland et al., 1991; Van den Berg andDonat, 1992; Wells et al., 1998). Therefore, thesetwo parameters, the ligands concentrations andconditional stability constants, are important todetermine the complexing capacity. Sea surface microlayer (SML), the thin interfa-cial boundary between ocean and atmosphere, playsan imp…     

统一监管 任重道远

最近,胡锦涛总书记对测绘工作做出了重要指示:“加强测绘统一监督管理和基础测绘工作”。这使广大测绘工作者很受鼓舞和振奋。领导同志的重视支持,新测绘法的颁布实施,可持续发展战略的深入推进,信息化进程的日益加快,都给测绘行业在更高层次更深领域更广范围的发展带来了前所未有的大好机遇。测绘业应当摆脱传统思想观念的羁绊,开阔视野,拓宽思路,勇于创新,迈开大步往前闯,呈现新的繁荣,为经济和社会发展做出更加实际更加突出的贡献。作为测绘管理工作,应站在全新的角度,既要从宏观着眼,加强测绘发展战略研究,制定好测绘发展规划和产业政策…