Coastal exposure to oil spill impacts from the Finisterre Traffic Separation Scheme

This study analyzes the coastal exposure to potential oil spills coming from the various corridors that constitute the Finisterre Traffic Separation Scheme (NW Iberia). A Lagrangian model was executed with results from a realistic configuration of an ocean model during 2012, validated here against High-Frequency (HF) radar-derived surface currents. Virtual particles were released each hour and followed during the next 4 days. A series of maps summarize which regions would be impacted and when. We have learnt, for example, that Cape Finisterre is the most affected area under a wide range of scenarios and that a sensitive area such as the National Park of the Atlantic Islands would require protective actions in less than 24 h if oil spills from the south eventually occurred. A complete analysis by corridor and during specific wind events is available through a web tool, which could be useful for decision makers in case of contingency.     

A new approach for separating mixed model parameters:application to simultaneous inversion of earthquake source parameters

A method for simultaneous determination of mixed model parameters,which have different physical dimensions or different responses to data,is presented.Mixed parameter estimation from observed data within a single model space shows instabilities and trade-offs of the solutions. We separate the model space into N-subspaces based on their physical properties or computational convenience and solve the N-subspaces systems by damped least-squares and singular-value decomposition. Since the condition number of each subsystem is smaller than that of the single global system,the approach can greatly increase the stability of the inversion. We also introduce different damping factors into the subsystems to reduce the tradeoffs between the different parameters. The damping factors depend on the conditioning of the subsystems and may be adequately chosen in a range from 0.1 % to 10 % of the largest singular value. We illustrate the method with an example of simultaneous determination of source history,source geometry,and hypocentral location from regional seismograms,although it is applicable to any geophysical inversion.     

Experimental study on flow pattern and sediment transportation at a 90°open-channel confluence

In this paper,the evolutions of flow pattern and sediment transportation at a 90° open-channel confluence with different discharge ratios (q*) of the tributary flow to the total flow were studied.The e...     

3D surface‐wave estimation and separation using a closed‐loop approach

Surface waves in seismic data are often dominant in a land or shallow‐water environment. Separating them from primaries is of great importance either for removing them as noise for reservoir imaging and characterization or for extracting them as signal for near‐surface characterization. However, their complex properties make the surface‐wave separation significantly challenging in seismic processing. To address the challenges, we propose a method of three‐dimensional surface‐wave estimation and separation using an iterative closed‐loop approach. The closed loop contains a relatively simple forward model of surface waves and adaptive subtraction of the forward‐modelled surface waves from the observed surface waves, making it possible to evaluate the residual between them. In this approach, the surface‐wave model is parameterized by the frequency‐dependent slowness and source properties for each surface‐wave mode. The optimal parameters are estimated in such a way that the residual is minimized and, consequently, this approach solves the inverse problem. Through real data examples, we demonstrate that the proposed method successfully estimates the surface waves and separates them out from the seismic data. In addition, it is demonstrated that our method can also be applied to undersampled, irregularly sampled, and blended seismic data.     

从废旧钴钐磁性材料中分离钴和单一镨,钕,钐的条件研究

本文用ＣＬ－Ｐ５０７萃淋树脂作为萃取色层的固定朴要研究了经Ｄ２３５阴离子树脂交换分离钴后和稀土镨钕钐的分离，对洗脱剂，洗脱条件进行了探讨，并选择出最佳分离条件。     

西藏甲玛斑岩成矿系统铜钼元素分离机制探讨

西藏甲玛矿床是冈底斯成矿带中东段目前勘查程度最高、第一个规模化开发的超大型斑岩成矿系统,主要由矽卡岩铜多金属矿体、斑岩钼(铜)矿体以及角岩铜钼矿体构成。文章以甲玛矿床角岩矿体和斑岩矿体中典型的"上铜下钼"现象为切入点,借助流体包裹体显微测温、激光拉曼测试、同步辐射X射线荧光分析(SR-XRF)等研究方法,分析了甲玛矿床铜钼矿化阶段成矿流体的物化条件差异及微量元素迁移行为。流体包裹体研究结果表明:铜矿化阶段流体温度(大致在235~451℃,主要集中在340~380℃之间)总体上大于钼矿化阶段流体温度(大致在213~500℃,主要集中在310~360℃之间),但两种成矿流体的盐度大致相似,主要位于18%NaCleqv与30%NaCleqv这两个区间,缺乏盐度中间过渡区,说明成矿流体经历了沸腾作用。激光拉曼显微探针测试结果表明,Cu矿化阶段的流体氧化性较Mo矿化阶段更强,而Mo矿化阶段流体略呈还原性。单个流体包裹体同步辐射X射线荧光分析显示,Cu、Au、Fe、Mn、S、As等元素主要在气相中广泛分布,而Mo则主要残留在液相中迁移富集。因此,本文认为甲玛矿床中角岩型和斑岩型矿体呈现"上铜下钼、早铜晚钼"现象,主要由铜、钼元素本身的物化性质,含矿岩浆性质和侵位顺序与深度,以及含矿岩浆后期所分异出的成矿流体的氧化还原性以及其中S含量的差异所致。     

离子交换树脂富集分离、火焰原子吸收光度法测定地质样品微量金

试验了四十多种常见存元及贵金属元素对富集和测定的影响。拟定了一个灵敏、快速、准确、成本低廉的地质样品中微量金的测定方法。结果令人满意，本法适用于一般地质样品中w(Au)/10^-6;0.05-50的测定。     

Phosphate Lu–Hf geochronology

Igneous, metamorphic and biogenic apatite contains Lu and Hf in proportions that make this mineral suitable for dating by the ¹⁷⁶Lu–¹⁷⁶Hf method. We present a new method for separation of Lu and Hf from apatite that involves a single extraction column step for Hf and a second exchange column step for Lu. This procedure allows rapid sample processing prior to analysis by MC-ICP-MS. Results from the igneous Gardiner, Skaergaard and Khibina Intrusions indicate that the closure temperature for the Lu–Hf isotopic system in apatite is relatively high. The Lu–Hf isochron age of 60 Ma for the Skaergaard Intrusion, East Greenland, is older than the generally accepted emplacement age, but does not appear to be a product of mixing. A centimeter-sized apatite from the Otter Lake area, Grenvillian Province, yields high and variable ¹⁷⁶Lu/¹⁷⁷Hf ratios showing that metamorphic apatite may, in some cases, allow for mono-mineral dating. The most important application of the method is undoubtedly its potential use for dating sedimentary formations. Although we find biogenic apatite in porous matrix highly susceptible to post-depositional resetting of the Lu–Hf isotopic system, the preservation of a near-depositional age for a shark tooth from the impermeable London Clay and recent work on crystalline authigenic phosphorites [Earth Planet. Sci. Lett. 201 (2002) 203] show the Lu–Hf system to be a promising tool for direct dating of sedimentary formations.     

面波压制的Ridgelet域方法

面波压制是地震数据处理中的一个重要问题. 常规的处理方法虽然能在一定程度上压制面波,但是在处理过程中只是单一的利用面波的一种特性,例如频率域滤波中利用面波与有效信号频率之间的差别,因此难以有效地压制面波. 利用Ridgelet变换可将原始地震记录拓展到（a,τ,p）三维空间,从而可以同时利用地震记录的视速度、时间和尺度域特性差别,实现有效信号与面波的分离. 文中通过理论合成记录及实际地震记录的算例,证实了基于Ridgelet变换的面波压制方法是有效且可行的.     

MgCl_2─KCl─H_2O体系相图的测定及其应用

测定了三元体系ＭｇＣｌ２─ＫＣｌ─Ｈ２Ｏ在２８℃与３０℃下的溶解曲线，并在此基础上结合文献中该体系一些温度下的溶解度曲线，对从盐卤提取的ＫＣｌ·ＭｇＣｌ２·６Ｈ２Ｏ复盐中ＫＣｌ的分离，提出一个简便可行的方法。