Chemical composition of wet deposition in a Mediterranean site Athens,Greece related to the origin of air masses

The goal of this study is to determine the chemical composition of rain, in the wider region of Athens, Greece for the time period 1st September 2001 to 31st August 2002. Two model automatic rain samplers were installed in the Meteorological Station of Laboratory of Climatology (latitude: 37° 58′ N, longitude: 23° 47′ E) inside the Athens University Campus and in a site at Heraklio Attica, a northern suburb of Athens (latitude: 38° 03′ N, longitude: 23° 45′ E). The concentrations (μeq l⁻¹) of the major cations (H⁺, Na⁺, K⁺, Ca²⁺ and Mg²⁺) and anions (Cl⁻, , και ), as well as pH and conductivity of rain in 39 total samples were determined. The figures of pH range from 6.4 to 8.4 and conductivity from 8 to 207 μS cm⁻¹. The analysis showed that Ca²⁺ ions are abundant within all examined samples, while and present the highest concentrations from the anions. In order to find out the origin of the air masses, the air mass back trajectories were calculated. Five sectors of the origin of air masses were revealed: the North, the South, the Local, the West and the East sector. Multivariate methods included Factor Analysis and Discriminant Analysis were applied to the examined ion concentrations and three main factors were extracted, which discriminated the ions according to their origin. The first group of ions is interpreted as the result of the anthropogenic activity, the second group represents the acidity–alkalinity independently of their source and the third one the marine influence.     

欧美地下水有机污染调查评价进展

1999年中国地质调查局启动了第一个地下水有机污染调查项目,当时检测指标只有20个(包括11个挥发性有机污染物、8种有机氯农药和1种多环芳烃)。“十一五”的地下水有机污染调查必测项目包含了38项(挥发性指标28项、有机氯农药9项和1种多环芳烃),取得了地下水有机污染的基本资料。但从对国外文献的调研来看,地下水中有机污染的种类远远超过38种。为了更全面地掌握中国地下水的质量,有必要对不同地区或不同类型的地下水中典型的有机污染物的种类进行研究,为后续地下水有机污染调查的增项做准备。通过检索美国环保局(USEPA)、美国地质调查局(USGS)和欧盟(EU)近年来的地下水质量年度报告和相关文献,调研了地下水中典型有机污染物的类型,选出最常检出的有机污染物,形成最常检出的有机污染物的检出率排序表,列出了检出率高的前50个污染物的名单。     

电荷屏蔽与超新星前身星阶段电子俘获

利用核的壳层模型，讨论了电荷屏蔽对超新星的前身星阶段一些较丰的核在一些重要的温度－密度点的电子俘获率的影响，结果表明由于电荷屏蔽的作用基电子丰度变化率下降了10－20％。     

云南勐海关双铁矿矿床成因

关双铁矿位于大南婆—惠民—西定金多金属矿富集区。矿床成因与澜沧惠民铁矿类似,属海相火山沉积变质型。     

个旧矿区地下水特征及控制因素

个旧矿区位于红河和南盘江两大水系的分水岭地带,属岩溶中山地貌,岩溶洼地、漏斗、落水洞等星罗棋布。矿区内无地表河流,地下水主要接受大气降雨补给。矿坑涌水量主要受大气降雨、岩溶发育程度、断裂构造及隐伏岩浆岩体控制。     

陆良石槽河煤矿充水因素及漏水量估算

石槽河煤矿位于断陷盆地中,可采煤层M3位于最低排泄基准面之下,无法自流排水,矿坑水主要来自煤层顶板、河水渗流及降水渗入。计算获得矿井漏水量为4472m3／d（正常）和6411m3／d雨季。     

Factor analysis in hydrogeochemistry of coastal aquifers – a preliminary study

 This paper examines the results of R-mode factor analysis performed on major ion data from a hydrogeochemical survey over the coastal Quaternary deltaic aquifer of the Cauvery Basin, Tamil Nadu, India. Seven major ions (Ca, Mg, Na, K, HCO₃, Cl, and NO₃) were analyzed from each of the 126 water samples collected in two seasons (pre- and post-monsoon 63 each). A set of factors was found both in pre-monsoon and post-monsoon data which explained the source of the dissolved ions and the chemical processes which accompany the intrusion of seawater. Received: 4 March 1996 · Accepted: 28 August 1996     

STATISTICAL F-TESTS FOR ABSTRACT FACTOR ANALYSIS AND TARGET TESTING

Fisher variance ratio tests are developed for determining(1)the number of statistically significantabstract factors responsible for a data matrix and(2)the significance of target vectors projected into theabstract factor space.F-tests,developed from the viewpoint of vector distributions,are applied tovarious data sets taken from the chemical literature.     

云南双江大亮山金矿控矿因素及成因分析

矿体赋存于韧性剪切带,矿化带近南北向分布,为岩浆期后中—低温热液通过富集作用形成的微粒、浸染型金矿.     

一次多普勒天气雷达故障排除实例分析

根据雷达工作原理、故障现象和故障原因,对桂林市新一代多普勒天气雷达天线动态故障问题的维修工作的总结分析,找出故障原因,维护注意事项和维修方法.