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71.
我国藻菌生物成因的金矿研究   总被引:1,自引:0,他引:1  
生物成矿作用分为生物直接成矿作用和生物间接成矿作用,生物直接成矿作用的标志结构为生物有机胶体结构。生物间接成矿作用的标志结构为“矿交代生物”结构,我国陕西二台子-半仓沟金矿,四川东北寨金矿、川甘拉尔玛金矿和云南金厂金矿等均为典型为实例,矿石中普遍含有多种金属矿物生物结构,还含多种生物有机组分。成矿物质具有多源性特征,硫同位素具混合型特征,矿床成型机制可与“人工碳吸附系统”聚金机制相类比,含金层位可  相似文献   
72.
Regularity of structural patterns can be connected to planetary disjunctive systems (paleosystems). A computerized universal model of these systems should be developed that may be helpful to predict unknown localities of mineral resources controlled by tectonic processes. The specific character of tectonic phenomena is to be respected in geomathematical models. Some suggestions for applications are given.  相似文献   
73.
Catalytic ozonation has attracted much attention in treatment of wastewater for its mild conditions. Phenol and its ramifications are common components in a wide variety of wastewaters including those from coal conversion processes, coking plants, petroleum refineries and several chemical industries. In this paper, natural brucite and magnesia have been successfully used in catalytic ozonation of phenol. And the mechanisms of catalysis were also investigated. From Figs. 1 and 2, it can be found that both brucite and magnesia have remarkable catalysis on degradation of phenol and removal of Chemical Oxygen Demand (COD). The pH of solutions on the process of ozonation alone, catalytic ozonation with brucites and with magnesia were 6.35-2.76, 10.18-8.52 and 10.58-10.83, respectively. It can be concluded that alkali environment plays a critical role for catalytic ozonation of phenol. We also found that the alkaline minerals reacted on the surface with oxalic acid and other low molecular-weight acids which are intermediate products in ozonation, but those intermediate products could be mineralized into carbon dioxide completely with enough ozonation time.  相似文献   
74.
四川盆地地下卤水资源优势及综合开发前景   总被引:3,自引:0,他引:3       下载免费PDF全文
四川盆地地下卤水自震旦系至白垩系各层系皆有分布。卤水具有分布广泛、资源丰富、品质优异、高承压及气卤同产等优势特点,是四川得天独厚的液态矿产资源。卤水中含有K+、Br-I、-、B3+、Li+、Sr2+、Rb+等多种有用组分,皆为国家紧缺和紧俏物质,其含量多数可达工业开采品位,为优质化工原料水,经济价值极高,综合开发利用前景广阔。  相似文献   
75.
The structure and dynamics of 2-dimensional fluids in swelling clays   总被引:3,自引:0,他引:3  
The interlayer pores of swelling 2:1 clays provide an ideal 2-dimensional environment in which to study confined fluids. In this paper we discuss our understanding of the structure and dynamics of interlayer fluid species in expanded clays, based primarily on the outcome of recent molecular modelling and neutron scattering studies. Counterion solvation is compared with that measured in bulk solutions, and at a local level the cation-oxygen coordination is found to be remarkably similar in these two environments. However, for the monovalent ions the contribution to the first coordination shell from the clay surfaces increases with counterion radius. This gives rise to inner-sphere (surface) complexes in the case of potassium and caesium. In this context, the location of the negative clay surface charge (i.e. arising from octahedral or tetrahedral substitution) is also found to be of major importance. Divalent cations, such as calcium, eagerly solvate to form outer-sphere complexes. These complexes are able to pin adjacent clay layers together, and thereby prevent colloidal swelling. Confined water molecules form hydrogen bonds to each other and to the clays' surfaces. In this way their local environment relaxes to close to the bulk water structure within two molecular layers of the clay surface. Finally, we discuss the way in which the simple organic molecules methane, methanol and ethylene glycol behave in the interlayer region of hydrated clays. Quasi-elastic neutron scattering of isotopically labelled interlayer CH3OD and (CH2OD)2 in deuterated clay allows us to measure the diffusion of the CH3- and CH2-groups in both clay and liquid environments. We find that in both the one-layer methanol solvates and the two-layer glycol solvates the diffusion of the most mobile organic molecules is close to that in the bulk solution.  相似文献   
76.
Risk and uncertainty assessments for waste containment systems employing clay barriers often include spatial variability in the hydraulic conductivity as part of the analysis. The two-parameter log-normal distribution is often used to describe the spatial variability, but for compacted clays the three-parameter form can be more appropriate. A statistical hypothesis test was developed that can be used to determine if the two- or three-parameter form of the log-normal distribution is more appropriate. The test is based on a likelihood ratio, comparing likelihood functions for the two- and three-parameter forms at their maximums. Likelihood functions are used assuming that a data set can be segregated into a set of distinct groups of hydraulic conductivities. A step-by-step calculation procedure is described and the test is applied to data collected from 45 sites.  相似文献   
77.
The arctic islands of the Lofoten-Vesterålen archipelago in northern Norway have a wide distribution of weathered land surfaces commonly located above 250 m with several apparent similarities. In order to investigate the characteristics of (deep) weathering in this region, northern Langøya and Hadseløya were chosen for in-depth analyses. Eight weathering profiles were excavated from various surfaces, and the stratigraphies were logged in detail. Material was collected throughout the weathering horizons, and all samples were subsequently analysed for clay mineralogy (< 63 μm fraction) and grain size distribution. The sampling strategy was complemented by samples from additional saprolites and other landforms such as moraines and rock glaciers. The XRD results indicate that the presence of secondary minerals, such as gibbsite (Al(OH)3) and kaolinite (Al2Si2O5(OH)4), are very common throughout the profiles. Gibbsite is an extreme end product of silicate weathering and usually associated with a warmer and more humid climate, as found in Scandinavia during the Tertiary. The grain size analyses (< 63 μm) show that the finer silt fractions (< 8 μm) tend to be high in the profiles (20–40%), with significant amounts of clay (5–15%) demonstrating that the regolith itself is susceptible to frost sorting mechanisms.10Be exposure dates from in situ quartz knobs on tors and boulders of local origin suggest > 40,000 years of subaerial conditions. Considering the steady surface erosion, this figure should be viewed as an absolute minimum age estimate. Mapping of the superficial sediments and geomorphological features of the study areas has revealed several common morphological features, which indicate dominance of glacial and periglacial processes in the areas lying below the lower boundary of blockfields (c. 250 m). The weathering mantles are not a periglacial end product, but rather a relict tertiary landform that were modulated by permafrost processes as well as biological processes at later stages. The regolith cover constrain the vertical extension of warm-based Quaternary ice sheets challenging the notion of a parabolic ice mass consuming every mountain top of Lofoten and Vesterålen.  相似文献   
78.
The paper presents a simple constitutive model for normally consolidated clay. A mathematical formulation, using a single tensor-valued function to define the incrementally nonlinear stress–strain relation, is proposed based on the basic concept of hypoplasticity. The structure of the tensor-valued function is determined in the light of the response envelope. Particular attention is paid towards incorporating the critical state and to the capability for capturing undrained behaviour of clayey soils. With five material parameters that can be determined easily from isotropic consolidation and triaxial compression tests, the model is shown to provide good predictions for the response of normally consolidated clay along various stress paths, including drained true triaxial tests and undrained shear tests.  相似文献   
79.
秦皇岛市矿产开发引发的地质环境问题及对策   总被引:2,自引:0,他引:2  
秦皇岛市矿产资源丰富,矿业已成为秦皇岛市特别是地方经济的支柱之一。伴随着矿业的发展,在矿产开发过程中引发的地质环境问题日益突出,如采空区地表变形(地面塌陷、地裂缝等)、岩溶塌陷、露天采矿边坡失稳、尾矿引发的泥石流、水土流失以及地貌景观的破坏等。这些地质环境问题主要分布在北部的山区和丘陵台地区。形成的原因复杂,主要有法制不健全、缺乏强制恢复机制、布局不合理、监管不到位、开采技术落后、不合理开采、资金缺乏以及从业者环保意识淡薄等方面的原因。对于矿山地质环境的保护,应采取加强立法、建立保证金制度、统一规划、加强监管、加大宣传力度以及建立责任追究制度等措施。  相似文献   
80.
为了回收大洋粘土制备白炭黑后残液中的Al3 ,并获得氧化铝超细粉体,实验选用NH3.H2O为沉淀剂,在常温下采用沉淀法使残液中Al3 以氢氧化铝形式沉淀并去除其它杂质离子,然后将得到的沉淀在1200℃灼烧,保温1h。利用IR和XRD测试了产物的物相组成和结构,证实实验可以获得纯度较高的α-Al2O3;而SEM和粒度分析结果显示产物粒度细小,部分颗粒可以达到纳米级;BET结果显示Al2O3的比表面积可达32m2/g。根据氧化铝结构和性能等优选的实验条件为大洋粘土的进一步开发利用提供了参考依据。  相似文献   
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