地下水中钼的含量及其与人群健康的关系

本文以丰富的实际资料，论证了地下水中微量元素钼形成的主要控制因素及其与人群健康的关系。     

含金岩石形变系与元素调整分配相关性的高温高压实验研究

含金岩石在温度３５０～４５０℃、围压３００ＭＰａ、轴压１００～１５０ＭＰａ蠕变状态下,Ａｇ、Ａｕ元素在黄铁矿、黄铜矿、闪锌矿等金属硫化物及石英、白（绢）云母中有富集的趋势;而在绿泥石、黑云母、钠长石及方解石等非金属矿物中,Ａｇ、Ａｕ元素丰度总体趋于降低。这一实验结果印证了构造动力是“成岩成矿”的重要因素之一。     

GPM双频降水测量雷达对降雪的探测能力分析

以双频降水测量雷达为主载荷的GPM卫星于2014年2月发射升空。由于轨道倾角以及仪器通道的设置,大大提升了对弱降水和降雪的探测能力。通过四次降雪个例,分析比较了双频降水测量雷达的三种扫描模式(Ku,KaMS和KaHs)对降雪探测能力的差异。结果表明:DPR相态产品和地面实际观测结果比较一致,固态降雪温度-0.5℃并且降雪发生时的风暴顶高度大多6 km。Ku波段雷达由于仪器灵敏度的大幅提高.对降雪的综合探测能力最强,而KaMs和KaHS也具有特定的作用。此外,为了保证衰减订正的精度,和非降雪部分的衰减相比,需要主要提高降雪衰减尤其是混合相态湿雪的衰减订正精度。     

南疆沙漠腹地大气边界层气象要素廓线分析

利用塔中80m观测塔梯度系统采集的2006年8月、10月和2007年1月、4月的风、温度、湿度资料,结合气象站的同步气象资料,对南疆沙漠腹地近地层四季的晴天平均风速、温度、湿度廓线分布特征进行分析。结果表明,晴天平均风速白天随高度升高增加缓慢,夜间较快,低层风速白天比夜间大,高层则白天比夜间小,春夏季风速较大;四季平均温度廓线表现为夜间辐射型、早上过渡型、白天日射型和傍晚过渡型等四种类型,早、晚过渡时间四季各有不同,日最低、最高温度出现时间四季则相差不大;冬季夜间比湿随高度升高而增大,整个80m近地层表现为逆湿状态,其他季节逆湿一般出现在0．5—1m、1～2m、32—47m、63—80m等4个层次上,各逆湿层出现的时间各季节有所差异。     

Geochemical evidence of paleogeography and paleoclimate during deposition of the 2nd Member of Kongdian Formation in Kongnan area

The 2nd Member of Kongdian Formation has been made up of a large number of oil shale and mudstone in the Kongnan aera of Huanghua depression around the Bohai Bay. In the Kongnan area, the lake basins were very large and deep during the deposition of the 2nd Member of Kongdian Formation. During that period,the lakes were sealed, uncommunieated with the sea water and the paleoclimate was very warm and wet in Kongnan area. Analyzing the content of the trace element and the rare earth element, carbon and oxygen isotope in the disquisition, The authors prove the two views correct.     

双相各向异性介质中弹性波方程的有限元解法及波场模拟

基于双相各向异性介质模型,首先推导了双相各向异性介质中弹性波传播的动力学方程及其Galerkin变分方程和有限元运动方程,然后给出了孔隙弹性波方程的有限元数值解法以及二维双相PTL介质中波场模拟的人为吸收边界条件. 最后,利用本文给出的有限元方法对双相PTL介质和双相各向同性介质中的弹性波传播进行了数值模拟. 结果表明:有限元方法和吸收边界条件有效、可行,在理想相界条件下,不论是从固体位移,还是从流体位移的波场快照都能看到明显的慢速拟P波;在黏滞相界情况下,能否观察到慢速拟P波,与含流体地层介质的耗散性质有关.对实际含流体介质,从流体位移分量的波场快照比从固体位移波场快照更容易观察到慢速拟P波.     

云南白秧坪银多金属矿床微量元素地球化学特征

云南白秧坪银多金属矿床是滇西兰坪盆地内新发现的矿床,属东特提斯喜马拉雅成矿域的一部分。矿床主要产于下白垩统景星组石英砂岩、粉砂岩中。本文从微量元素地球化学研究入手,与滇西喜马拉雅期富碱岩体相比较,它们具有相同的物质来源区,这种源区被认为是壳幔物质混合的一种"EMⅡ型"富集地幔源。     

Geochemistry of Paraná-Etendeka basalts from Misiones,Argentina: Some new insights into the petrogenesis of high-Ti continental flood basalts

The Early Cretaceous (∼135–131 Ma) Paraná-Etendeka continental flood basalts, preserved in bulk in the Paraná basin of southern Brazil and vicinity, have been divided into low-Ti and high-Ti types that govern the southern and northern halves of the basin, respectively. We have examined a new sample set from the southern margin of the northern high-Ti segment of Paraná basalts in Misiones, northeastern Argentina. These basalts are strongly to moderately enriched in TiO₂ (2–4 wt.%), have relatively high Ti/Y (300–500), low MgO (3.5–6.5 wt.%), and high Fe (FeO(tot) 12–14 wt.%) and belong to the Pitanga and Paranapanema magma types of Peate et al. (1992). Nd and Sr isotope compositions are quite unvarying with ε_Nd (at 133 Ma) values of −4.6 to −3.6 and initial ⁸⁷Sr/⁸⁶Sr of 0.7054–0.7059 and show no variation with fractionation. Compared to high-Ti lavas in the central and northern parts of the Paraná high-Ti basalt segment, the lavas from Misiones are similar to those in the northeastern magin of the basin but less radiogenic in initial Nd isotope composition than those in the central part. This variation probably reflects mixed EM1-EM2 source components in the sublithospheric mantle. A polybaric melt model of a sublithospheric mantle source at the garnet lherzolite-spinel lherzolite transition is compatible with the observed Ti budget of the Pitanga and Paranapanema lavas, regardless of the Nd isotope composition of their purported source.     

Multi-factor sensitivity analysis on the stability of submarine hydrate-bearing slope

There are many factors affecting the instability of the submarine hydrate-bearing slope (SHBS), and the interaction with hydrate is very complicated. In this paper, the mechanical mechanism of the static liquefaction and instability of submarine slope caused by the dissociation of natural gas hydrate (NGH) resulting in the rapid increase of pore pressure of gas hydrate-bearing sediments (GHBS) and the decrease of effective stress are analyzed based on the time series and type of SHBS. Then, taking the typical submarine slope in the northern South China Sea as an example, four important factors affecting the stability of SHBS are selected, such as the degree of hydrate dissociation, the depth of hydrate burial, the thickness of hydrate, and the depth of seawater. According to the principle of orthogonal method, 25 orthogonal test schemes with 4 factors and 5 levels are designed and the safety factors of submarine slope stability of each scheme are calculated by using the strength reduction finite element method. By means of the orthogonal design range analysis and the variance analysis, sensitivity of influential factors on stability of SHBS are obtained. The results show that the degree of hydrate dissociation is the most sensitive, followed by hydrate burial depth, the thickness of hydrate and the depth of seawater. Finally, the concept of gas hydrate critical burial depth is put forward according to the influence law of gas hydrate burial depth, and the numerical simulation for specific submarine slope is carried out, which indicates the existence of critical burial depth.     

Kinematic source model for simulation of near-fault ground motion field using explicit finite element method

1 Introduction The prediction of broadband near-fault ground motion is an important aspect of seismic risk analysis, and is essential for the evaluation of urban seismic safety. Many methodologies are used to model the near-fault ground motions, such as the Green function method, ?nite element (FE) / ?nite difference (FD) method and a hybrid method (Aagaard, 1999; Oprsal and Zahradnik, 2002; Oprsal et al., 2003 a and b). In the hybrid method, the FE / FD method is used to model the low fr…