黔中地区蔡家坝铝土矿床富锂铝土岩地球化学特征及沉积环境研究

贵州清镇蔡家坝铝土矿床是近年来在黔中铝土矿成矿区内新发现的铝土矿床之一,铝土矿体呈层状及似层状产于下石炭统九架炉组地层中。本研究通过对蔡家坝铝土矿床中以铝土岩为主的含铝岩系钻孔岩心剖面开展详细的矿物学和地球化学研究,发现含铝岩系中的铝土岩明显具有Li超富集的现象。研究结果表明,含铝岩系的所有样品中均富含高浓度的Li（210~2480）×10-6;其中,10件铝土岩的Li含量为（210~2480）×10-6（平均1198.9 ×10-6）,3件铝土矿石的Li含量为（412~1440）×10-6（平均980.7×10-6）,表现出明显超富集的特征。光学显微镜和XRD分析显示,富锂铝土岩主要由伊利石、高岭石和绿泥石组成,以及少量的硬水铝石、勃姆石、黄铁矿、锐钛矿等。结合矿物学和地球化学证据,研究区铝土岩中的Li主要赋存在高岭石和伊利石等粘土矿物中,当铝土岩中Al2O3含量介于30%~40%之间以及Al2O3/SiO2比值介于1~1.5时,铝土岩中的Li最为富集。元素地球化学分析表明,研究区内的富锂铝土岩形成于温暖潮湿和相对氧化的陆相淡水环境。     

在网络环境下的图书馆计算机编目

叙述了计算机编目的重要性,分析了图书馆计算机编目的现状和面临的挑战,阐述了网络环境下图书馆计算机编目内容和形式的扩展,并根据成都气象学院图书馆计算机编目的现状提出了相应的对策。     

CSCO_3 CYCLES IN SALAWUSU RIVER BASINSINCE 150KA B.P.

About 70years ago，Frenc卜卜alaeohdoglst回LL sc卜dars al卜ome and a卜road卜ave successively con－HARD de Chardin P．et al．Initiated the Quaternary ducted large amount ofwork on the Later Quaternarygeologlcal research In the ＞alawusu River Basin of strata（TEILHARD，1924； YUAN，1978； LI，1987；desert region of Northern China and established th，ZHENG，1989； SUN et al，1996； LI et al，1993），Salawusu Formation门EILHARD，1924）．Sine，then，palaeobiology…     

鲜水河断裂带的构造大地测量

利用短边GPS点阵、短基线标石阵和精密激光测距 ,在与鲜水河断裂带的断层破裂带垂直的剖面上和构造盆地内进行构造大地测量 ,获得了断层软弱带和断层蠕变带上的最佳形变分布。综合利用相关地学成果和理论 ,揭示了构造形变所隐含的动力学信息 ,识别了断层应变带、塑性流变带和主断面在地面的分布范围。用外围GPS远场联测成果探讨了该断裂带的驱动力机制 ,匡正了其“左旋”运动和现今活动速度的含义。最后 ,评估了该断裂的地震活动趋势     

Subsurface flow processes in sloping cropland of purple soil

Subsurface flow is a prominent runoff process in sloping lands of purple soil in the upper Yangtze River basin.However,it remains difficult to identify and quantify.In this study,in situ runoff experimental plots were used to measure soil moisture dynamics using an array of time domain reflectometry(TDR) together with overland flow and subsurface flow using isolated collecting troughs.Frequency of preferential flow during rainfall events and the controls of subsurface flow processes were investigated through combined analysis of soil properties,topography,rainfall intensity,initial wetness,and tillage.Results showed that subsurface flow was ubiquitous in purple soil profiles due to welldeveloped macropores,especially in surface soils while frequency of preferential flow occurrence was very low(only 2 cases in plot C) during all 22 rainfall events.Dry antecedent moisture conditions promoted the occurrence of preferential flow.However,consecutive real-time monitoring of soil moisture at different depths and various slope positions implied the possible occurrence of multiple subsurface lateral flows during intensive storms.Rainfall intensity,tillage operation,and soil properties were recognized as main controls of subsurface flow in the study area,which allows the optimization of management practices for alleviating adverse environmental effects of subsurface flow in the region.     

Taxonomic and genetic status of lancelet in Weihai coastal waters based on mitochondrial DNA sequence

Lancelets (subphylum Cephalochordata) are a transitional species between invertebrates and vertebrates. They are currently listed in the Second Order of Protected Animals in China. Lancelets were first documented in the waters around the city of Weihai (Shandong, China) in 2002. However, little is known about the phylogeny of this population. We analyzed the sequences of cytochrome b (Cyt b) and cytochrome oxidase c subunit I (CO I) genes from samples collected from coastal waters in the cities of Weihai and Qingdao (~150 km to the south). We analyzed 176 sequences, of which 150 were novel sequences and 26 were obtained from GenBank. Our results suggest that (1) lancelets in the two cities belong to the species Branchiostoma japonicus and have a high level of genetic diversity; (2) there is a high level of gene flow and low level of genetic differentiation between lancelets from the two cities; (3) demographic expansion occurred an estimated 1.1 million years (Ma) ago (mid Pleistocene) for lancelets in Weihai-Qingdao; and (4) the divergence between B. belcheri and B. japonicus was estimated at between 37.75 Ma (early Oligocene)-46.5 Ma (late Eocene).     

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f-3项与投影函数对电离层延迟的影响

依据Chapman正常电离层理论,构造Chapman剖面函数加权投影函数,给出VTEC三角多项式模型,并以武汉站2005年1月1日观测数据进行实例解算,分析电离层延迟f-3项、电离层单层高度、电离层投影函数形式等对电离层延迟的影响.     

水库重力测量检测非牛顿引力的实验数据分析新方法

本文提出水库重力测量检测非牛顿引力的实验数据分析新方法。利用近一天两重力仪的重力差值信号,基于同液面高度变化水体重力信号相等这一具有明显物理意义的准则,建立仪器零漂信号多项式系数矢量的矩阵方程,通过极大似然反演比较严格地计算漂移信号,并从中提取检测信号。实例计算结果表明:(1)当数据充分、漂移多项式阶数取值适当时,该方法完全有效;(2)在现有水库实验的设备和技术条件下,测定万有引力常数G对实验室值的偏离精度可达0.15％,优于矿井实验和先前水库实验的分析结果;若进一步改善水面高度测量,检测精度还可明显提高;(3)Hornberg水库实验重力仪G709在0.4％的精度范围内,未发现G对实验室值的偏离。     

SEA LEVEL RISE OF THE ZHUJIANG RIVER DELTA AND NEOTECTONICS

A linear regression analysis of 28 selected tide-gauge stations of the Zhujiang Estuary shows that there has been a tendency of local sea level rise at a rate of 2.028 mm per year. The origin of the variation is significantly attributed to the local tectonic movement of discrepant fault-block. Based on this, four types of relative local sea level changes are classified. According to calculation, half of the fertile land, or 800 km2 of the delta plain will have been submerged by sea water by about 2040. This will yield a significant influence on the economic construction and human activities.