铂族元素迁移富集机理的新探   总被引：2，自引：1，他引：2  

郑大中 《四川地质学报》1997,(2)

在岩浆及高温热液中，拍族元素以纳米液态铂族元素单质、铂族元素与其它金属元素的纳米液态合金、纳米液态铂族元素的硫、砷化物迁移。在中、低温热液及表生条件下，除呈上述固态纳米铂族矿物随流体迁移外，还呈配合物形式迁移。然后它们在合适的条件下沉淀富集形成矿床。此外，还讨论了铂族元素与金地球化学条件的异同。  相似文献   

ICAP仪器主要工作条件的优化方法研究     

管奕  常平  王松君 《吉林大学学报(地球科学版)》1996,(1)

ＩＣＡＰ仪器在不同工作条件下，其测试精度与准确值差别是较大的。因此，正确进行工作条件的优化，是ＩＣＡＰ仪器分析工作的关键。本文从理论依据及实验方法两个方面探讨了实现条件优化的具体方法，以及其对于确保仪器的最佳测试状态和进一步扩大测试领域所具有的实际意义。  相似文献   

Transport in a 2-D saturated porous medium: A new method for particle tracking   总被引：2，自引：0，他引：2  

Frédérick Delay  Hélène Housset-Resche  Gilles Porel  Ghislain de Marsily 《Mathematical Geology》1996,28(1):45-71

A new method for solving the transport equation based on the management of a large numbe of particles in a discretized 2-D domain is presented. The method uses numerical variables to represent the number of particles in a given mesh and is more complex than the 1-D problem. The first part of the paper focuses on the specific management of particles in a 2-D problem. The method also would be valid for three dimensions as long as the medium can be modeled similar to a layered system. As the particles are no longer tracked individually, the algorithm is fast and does not depend on the number of particles present. The numerical tests show that the method is nearly numerical dispersion free and permits accurate calculations even for simulations of low-concentration transport. Because each mesh is considered as a closed system between two successive time steps, it is easy to add adsorption phenomenon without any problem of numerical stability. The model is tested under conditions that are extremely demanding for its operating mode and gives a good fit to analytical solutions. The conditions in which it can be used to best advantage are discussed.  相似文献   

Surface chemical analysis in coal preparation research: complementary information from XPS and ToF-SIMS     

A. N. Buckley  R. N. Lamb 《International Journal of Coal Geology》1996,32(1-4)

The application of X-ray photoelectron spectroscopy (XPS) to coal surface characterisation for preparation research is described. Progress towards the acquisition of complementary surface chemical information by time-of-flight secondary ion mass spectrometry (ToF-SIMS) is also discussed. Surface-based beneficiation techniques such as flotation are assuming greater importance as the proportion of fines in raw coal increases due to the proliferation of high capacity mining methods. A necessary condition for the floatability of a coal particle is adequate hydrophobicity, and the degree of hydrophobicity of the flotation concentrate is one factor influencing the ease with which its dewatering can be affected. The hydrophobicity of a coal is very difficult to measure directly because of microporosity, and it is often necessary to deduce the degree of hydrophobicity from a knowledge of the surface chemistry. XPS is able to provide sufficient analytical data to allow relative levels of hydrophobicity to be estimated. In principle, ToF-SIMS should be able to supply additional information enabling refinement of such estimates; however, there are insufficient data at present to allow the ionic fragments detected to be related to specific functional groups at the coal surface.  相似文献   

计算样本相似性在油气预测中的应用     

朱晓军  申宁华 《世界地质》1996,15(2):87-91

介绍了计算样本相似性方法在油气预测中的应用的基本原理和技术。提出了利用参数的显著性进行参数优化和加权的方法。该方法简单、实用，并在塔北某区的应用取得了满意结果。由此证明了该方法的有效性及在综合信息预测工作中进行参数优化和加权工作的重要性。  相似文献   

地下巷道弹性位移反分析各种优化方法的探讨   总被引：16，自引：5，他引：16  

吕爱钟 《岩土力学》1996,17(2):29-34

探讨了６种最优化方法（鲍威尔法、单纯形加速法、阻尼最小二乘法、变尺度法、模式搜索法和变量轮换法）在巷道弹性位移反分析中的应用情况。从参数初始点的选择、收敛速度、收敛精度和可靠性方面评价了这６种无约束最优化方法的优劣。  相似文献   

Geochronology, geochemistry and tectonic implications of Xiongshan diabasic dike swarm, northern Fujian     

Shengli Ren  Jiliang Li  Xinhua Zhou  Min Sun 《中国科学D辑(英文版)》1997,40(4):411-417

Sm/Nd isotopic age determination showed that Xiongshan dike swarm was at 585.7 Ma ± 30 Ma. The trace element geochemistry and Sr/Nd/Pb isotope gemhemistry studies indicate that the dike swarm was products of back-arc basin spreading ridge and the magma originated from the depleted mantle region which was metasomatized by LILE-rich liquids/melts derived from subduction slab. Project supported by the National Natural Science Foundation of China.  相似文献   

计算机内存的分类及优化管理     

范崎 《华东地质学院学报》1997,20(3):284-287

本文从计算机应用角度出发，介绍了计算机内存的基本结构及其类型内存配置对计算机工作的影响，同时讨论了如何合理计算机内存，以便充分发挥计算机的优势。  相似文献   

2003年6月青岛崂山4级震群序列初步分析   总被引：2，自引：0，他引：2  

潘元生  侯海锋  万连初  邓向明  史雯  周焕鹏 《内陆地震》2004,18(1):77-83

从震群监测、地震影响、地震地质构造、序列特点及性质判定等方面对2003年6月青岛崂山王哥庄发生的4级震群进行了介绍及初步分析。此次地震的活动强度、频次、持续时间均为青岛历史上所罕见。地震时整个青岛市普遍有感，震中区有一定破坏，造成较大的社会影响。  相似文献   

基于复模态的有限元模型修正算法   总被引：2，自引：0，他引：2  

陈健云  王建有 《世界地震工程》2004,20(2):12-16

针对地下结构地震响应分析中无限地基辐射阻尼问题，引入复模态情况下的具有非简化的堆积阻尼矩阵的阻尼模型，并针对具有集中质量阵的阻尼模型提出了合并与质量有关的阻尼和堆积阻尼的思想，并据此提出了一种修正此类有限元模型的两步法，首先从复模态参数中提取实模态参数，采用基于模态残余力的识别算法修正刚度矩阵，然后根据复模态参数和已得的刚度矩阵来识别阻尼模型中的刚度参与系数和质量阻尼堆积阻尼联合矩阵。  相似文献