熔体形态学及其对岩石物理和力学性质的影响   总被引：1，自引：0，他引：1       下载免费PDF全文

周平  杨晓松  王多君 《地球物理学进展》2006,21(3):790-797

简要回顾了熔体形态学的研究方法，并分别从熔体分数和熔体分布形态两个方面，综合前人在熔体对岩石物理和力学性质的影响领域的主要研究成果，认为在部分熔融初期，熔体分数小，熔体主要分布于孤立的熔体囊内，对岩石的电学性质和力学性质影响不大，但是，对岩石的弹性波波速影响却很明显；随着熔体分数的增大，孤立的熔体囊逐渐连通形成熔体管道网络，岩石的电学性质发生显著变化；当熔体分数增至某一临界数值时，岩石体系结构改变，岩石的力学性质发生突变.  相似文献   

The effect of subaerial exposure on the morphology and microstructure of stromatolites in the Cretaceous Sinyangdong Formation,Gyeongsang Supergroup,Korea1     

O. NEHZA  K. S. WOO 《Sedimentology》2006,53(5):1121-1133

Stromatolite morphology is usually controlled by a number of biological and environmental factors. In the south‐eastern part of the Korean Peninsula, three stromatolite units of the Cretaceous Sinyangdong Formation have been studied with regard to the effect of diagenesis on their morphology. Here, it is proposed that subaerial exposure and meteoric diagenesis are the most significant factors in shaping the stromatolites of the Cretaceous Sinyangdong Formation. Most previous palaeontological and sedimentological studies on stromatolites have concentrated on the environmental and biogenic controls on stromatolite morphology. These include extrinsic factors such as sedimentation rates or current velocities. The main controlling factor on the morphology of the stromatolites in the Sinyangdong Formation is apparently transient subaerial exposure and related meteoric diagenesis. Textural examination of stromatolite samples from three stratigraphic horizons shows a characteristic repetitive pattern of cycles with gradual transition from fibrous calcite to micrite layers, reflecting changes in the hydrological cycle of the lake in which the stromatolites grew. Stromatolite growth was terminated by corroded surfaces indicative of subaerial exposure related to a fall in lake level. The growth pattern of the stromatolites was mostly determined by the morphology of the corroded substrates during subaerial exposure. Furthermore, the internal stromatolite structure was strongly modified by the process of leaching. As a result, growth forms mostly changed from stratiform to columnar mesostructure. This study strongly implies that diagenesis could make a very significant influence on the morphogenesis of lacustrine stromatolites in the geological past.  相似文献   

Adsorption and flocculation behaviors of polydiallyldimethylammonium (PDADMA) salts: Influence of counterion     

Binghui Tian  Xiaopeng GeGang Pan  Bin FanZhaokun Luan 《International Journal of Mineral Processing》2006

Two modified polymer flocculants of PDADMA salts, PDADMA nitrate (PDADMAN) and PDADMA sulfate (PDADMAS), were prepared from the most widely used commercial product of polydiallyldimethylammonium chloride (PDADMAC). Solution properties such as conductivity and viscosity were investigated, showing that the conductivity follows the order of PDADMAS > PDADMAC > PDADMAN, while the reduced viscosity increases in the order of PDADMAS < PDADMAC < PDADMAN. The results indicate that, compared with PDADMAC, PDADMAN has a more cationic density and a more extended polymer chain, whereas PDADMAS exhibits a smaller coiled polymer size because of the stronger charge affinity of sulfate ion to the polycation of PDADMA. Flocculation experiments were performed on kaolin suspensions. It was found that PDADMAN is the most efficient in turbidity removal, while PDADMAS has wider optimum dosages, larger floc size and more rapid settling rate. Atomic force microscopy (AFM) was employed for imaging the adsorption structures of the three polymers on the negatively charged mica surface. Remarkable differences in molecular conformation were observed. Compared with the pearl necklace-like aggregation of hemispheroids of PDADMAC polymer, PDADMAN takes a sponge-like thin layer structure and PDADMAS exhibits a uniform hemispherical structure.  相似文献   

宜春-新余一带岩溶基本特征及发育规律分析     

刘细元  马振兴  杨永革  秦岩  王道英 《华东地质学院学报》2006,29(2):127-132

宜春—新余一带,可溶岩地层总厚度近2 000 m,受岩性、地质构造、地形地貌及新构造运动的影响,岩溶地质现象发育。岩溶形态类型丰富,主要有溶沟溶槽、石芽、溶蚀洼地、漏斗、落水洞、伏流暗河及隐伏岩溶。文章全面阐述了研究区岩溶的形态类型及其分布特征,分析和总结了岩溶的发育规律。这对区内的城镇规划建设、确保岩土工程和城镇供水安全等都具有重要意义。  相似文献   

Soil morphology and organic matter dynamics under cheatgrass and sagebrush-steppe plant communities     

Jay B. Norton  Thomas A. Monaco  Jeanette M. Norton  Douglas A. Johnson  Thomas A. Jones 《Journal of Arid Environments》2004,57(4):445

Widespread cheatgrass (Bromus tectorum L.) invasion represents a major shift in species dominance that may alter ecosystem processes across much of the western US. To investigate differences following such conversion, soil morphology and organic matter under cheatgrass-dominated and native shrub-steppe vegetation were compared by standard soil analysis procedures at seven paired sites in Idaho and Utah. Results suggest that, following conversion to cheatgrass dominance, increased porosity and labile organic inputs enhance microbial decomposition in near-surface horizons beneath cheatgrass compared to adjacent soils under native vegetation. Enhanced decomposition could result in depletion of long-term SOM, leading to impoverished sites difficult to restore to native perennial vegetation.  相似文献   

MSCMO：基于数学形态学算子的尺度空间聚类方法   总被引：1，自引：0，他引：1  

汪闽  周成虎  裴韬  骆剑承 《遥感学报》2004,8(1):45-50

提出了一种基于数学形态学算子的多尺度聚类方法 :首先将数据进行二值图像化处理 ,利用一次闭开运算去除噪声干扰后再利用逐步增大结构元素的闭运算构建尺度空间 ,图像内的连通单元集随着尺度上升不断融合 ,最终全部归并。将连通集覆盖下的点集归为一类 ,以上步骤就对应了一个多尺度层次聚类过程。本算法的一个最大优点是聚类个数事先无需设定 ,而被确定为跨越最多尺度 (具有最长尺度生存期 )的类别个数。此外 ,参数少、能够提取任意形状的类别、具有较强的抗噪声能力也是算法的优点。对自构建数据与地震数据的聚类实验验证了方法的有效性和实用性  相似文献   

Processing of Laser Scanner Data and Extraction of Structure Lines Using Methods of the Image Processing   总被引：3，自引：0，他引：3  

SUILi-chun 《测绘学报》2004,33(1):63-70

激光扫描数据提供了一种新的手段用于获取高精度的数字地形表面模型. 原始的航空激光扫描数据表达的是一些非规则分布的"点云", 这些非规则分布的点需要进行有效的事后处理. 这种事后处理有2个目的:一是将那些分布在地表面上的点(即地面点)与分布在非地表面上的点(譬如树木、房屋或汽车上的点, 即非地面点)进行有效的分离;二是从分离后的地面点中提取结构线, 用于建立高精度的数字地面模型. 作者发展了一系列的基于数字形态学理论和稳健参数估计理论的方法用于分离和探测地面点. 这里所介绍和开发的提取结构线的算法建立在数字图像处理和表面曲率理论的基础上. 这些算法同样可以扩展地用于其他领域. 所介绍的基于数字图像处理理论处理原始的航空激光扫瞄数据和提取结构线的方法取得了很好的结果. 这一结论可以在本文中通过一系列的插图得到有力的证明.  相似文献   

一种保特征的形态采样方法     

段汕  秦前清 《测绘信息与工程》2004,29(1):4-7

提出了基于图像特征的形态采样方法,以反映图像某种重要信息的参考图像为加权模板,实现了在图像采样过程中保持图像形状及几何特征的相对不变性,研究了基于形态采样的图像形态多尺度分解方法.  相似文献   

Impact of salt stress on the features and activities of root system for three desert halophyte species in their seedling stage   总被引：1，自引：0，他引：1  

YI LiangPeng  MA Jian  LI Yan 《中国科学D辑(英文版)》2007,50(Z1):97-106

Linkage between belowground and aboveground sections of ecological system is mainly depending on root system. But root system is the parts of plant that people less understand. The absorption function of root system is closely related to their morphology and activity. Moreover root system can interact with the environmental stress under the adverse situation, and adjust its system to take adaptation responses in morphology and physiology to strengthen its survival chance. This research is focused on three desert halophyte species of H. ammodendron (C.A.Mey.) Bge., S. physophora Pall., and S. nitraria Pall. under solution culture, to study the differences of their root system morphology and activity in the seedling stage under varying salt concentration conditions. The study results show that: A certain salt concentration can promote development of these three halophytes; but rather high salt concentration will restrain their growth, in particular inhibit the root system development. Under the same salt concentration condition, S. nitraria Pall. grows fast and accumulates the largest amount of biomass. Under relatively low salt concentration, the length of axial root and the total length of root system of these three halophyte species are all increased; and compared to the checking samples, S. physophora Pall. occupies the top place of root system growth, but the high salt concentration will restrain the increase of total root length; among them, the impact intensity on S. physophora Pall. is lighter than to H. ammodendron (C.A.Mey.) Bge. and S. nitraria Pall. is lighter; the salinity does not bring distinct influence on the average diameter of root system of these three plant species, but trends to reducing the size; under the solution culture conditions, the middle and lower parts of the axial root of H. ammodendron (C.A.Mey.) Bge. and S. physophora Pall. are rather equally distributed, but the central zone of S. nitraria Pall. root system is more significantly increased than the upper and lower zones; salt concentration does not bring significant impact on the root system spatial distribution of each species. The root activity of the three plants is increased along with the increase of the salt concentration. When the salt concentration is low, the root activity is not significantly increased; but when the salt concentration is high, the root activity is increased significantly. The experimental results show that the saline tolerance capacity of H. ammodendron (C.A.Mey.) Bge. is lower than the other two species, and the capacity of S. physophora Pall. ranks the top place.  相似文献   

A new approach to the three-dimensional quantification of angularity using image analysis of the size and form of coarse aggregates   总被引：1，自引：0，他引：1  

J.R.J. Lee  M.L. Smith  L.N. Smith 《Engineering Geology》2007,91(2-4):254-264

This paper describes a system for the acquisition and analysis of 3D data from the surfaces of coarse aggregate particles. The technique uses laser triangulation to acquire data from the upper hemispheres of particles passing along a conveyor belt. Methods of determining particle size and form in three dimensions are described and a new approach to the quantification of angularity is presented. The algorithm uses mathematical morphology to provide a geometrically meaningful interpretation of particle shape. The relative advantages of 2D and 3D analysis of aggregate particles are discussed, and results are presented which demonstrate the validity of this approach.  相似文献