观赏石的分类与审美   总被引：2，自引：0，他引：2  

赖绍民 《四川地质学报》1996,(3)

从观赏石是自然形成的具有观赏价值的石质艺术品这一认识出发，将观赏石分为造型石、图纹石、矿物晶体石、古生物化石、纪念石和特殊石６大类。又以观赏石的地域审美观为指导，从色泽、形态、图纹、质感、组合、使巧、命名和意境８个方面对观赏石的审美进行了探讨。  相似文献   

Dissolved carbon in pore waters from the carbonate barrier reef of Tahiti (French Polynesia) and its basalt basement     

R. Fichez  P. Harris  G. Cauwet  P. Dejardin 《Aquatic Geochemistry》1996,2(3):255-271

This paper deals with dissolved inorganic carbon (DIC) and organic carbon (DOC) in pore waters from a 150 m deep hole drilled through the carbonate barrier reef of Tahiti and its underlying basalt basement. Alkalinity-pH measurements were used to calculate the DIC species concentration, and DOC was analysed according to the high temperature catalytic oxidation technique. Salinity was used as a conservative tracer to help identify water origin and mixing within the hole. Water mixing, calcium carbonate dissolution and mineralization of organic carbon combined to form three distinct groups of pore water. In the deeper basalt layers, pore water with alkalinity of 1.4 meq kg^–1 pH of 7.6 and p(CO₂) of 1.2 mAtm was undersaturated with respect to both aragonite and calcite. In the intermediate carbonate layer, pore water with alkalinity of more than 2.0 meq kg^–1, pH of 7.70 and p(CO₂) of 1.4 mAtm was supersaturated with respect to both aragonite and calcite. The transition zone between those two groups extended between 80 and 100 m depth. The shift from aragonite undersaturation to supersaturation was mainly attributed to the mixing of undersaturated pore waters from the basalt basement with supersaturated pore waters from the overlaying limestone. In the top of the reef, inputs from a brackish water lens further increased p(CO₂) up to 5.6 times the atmospheric P(CO₂).  相似文献   

碎石桩加固冷却塔地基效果的检测技术与质量评价     

黄理兴  陈平 《岩土力学》1996,17(4):70-77

介绍了安阳电厂冷却塔碎石桩复合地基静载、动力触探、瑞利波法系列原位试验。根据试验结果，对冷却塔地基加固与改良效果及施工质量进行了评价。  相似文献   

华宁盘溪金山-大石山泥盆纪珊瑚礁的基本特征     

洪天求  戴清明 《吉林大学学报(地球科学版)》1997,(1)

滇东华宁盘溪火车站以北的金山—大石山地区发育中、晚泥盆世的丘状珊瑚礁。以Ａｌｖｅｏｌｉｔｅｓ和Ｔｈａｍｎｏｐｏｒａ为代表的床板珊瑚为造礁生物。纵剖面上岩相变化的记录清楚地表明，该礁体经历了定殖、繁殖和衰亡三个阶段。海水变浅及其盐化是导致礁体衰亡的直接原因  相似文献   

湖南慈利晚二叠世海绵礁与珊瑚礁的古生态研究   总被引：5，自引：0，他引：5       下载免费PDF全文

王永标  徐桂荣 《地球科学》1997,22(2):135-138

中国南方晚二叠世生物礁分布广泛，但绝大多数属于海绵礁，湖南慈利晚二叠世除发育有海绵礁外，还有至今为止发现的世界上发育最好的古代珊瑚礁，而且海绵礁与珊瑚礁在同一条带上连续分布；因此是研究海绵礁与珊瑚礁古生态关系十分理想的场所，通过对慈利晚二叠世海绵礁及珊瑚礁内部造礁生物群落、沉积相特征，礁化演化序列及成岩作用特征等的分析和对比来研究它们之间的生态关系，发现其中的海绵礁为台地边缘礁，而珊瑚礁则应属于岸  相似文献   

具有经济性前景的粗岩屑堆天然冷能集聚分析     

Aldar P. Gorbunov 《冰川冻土》2004,26(Z1):197-200

The coarse-detrital deposits have the properties of cold accumulation and maintenance of cold for a long time. Now, at some place where the mean annual temperature of air is positive, one even can get the permafrost by artificial formation of the burial mound. According to these properties, some lowenergy storehouses are built for various purposes.  相似文献   

Laboratory and case studies of thermal cycling and stored strain on the stability of selected marbles     

John M. Logan 《Environmental Geology》2004,46(3-4):456-467

Studies of marble panels from the exterior of two buildings document the processes leading to bowing of the material. Bowing of panels is most extensive in those areas that are exposed to direct or reflected thermal energy. The thermal anisotropic behavior of calcite results in grain-boundary separation, grain sliding and microfracturing. The resulting loss of strength is one factor leading to bowing. The development of bows further reduces the panel strength as the outer portions elongate by inelastic deformation mechanisms. Laboratory experiments cycling marble samples for over 200 cycles at three temperatures up to 107°C above room conditions show similar strength losses as the natural situation. The second factor contributing to the bowing process is the release of residual elastic strain. The strain is in part stored in the marble from its geologic history, but may also be accumulated during thermal cycling due to the properties of calcite. Marble panels have been found to bow when stored outside, but not attached to any framework, indicating that the release of residual strain is a critical factor in producing the bows.  相似文献   

碎石桩复合地基检测分析          下载免费PDF全文

郑俊  刘兴 《探矿工程》2004,31(11):4-6

结合南京钢铁集团新钢铁厂碎石桩复合地基工程实例，从桩身的密实性和连续性、桩体周围土的隆起量以及桩间土挤密效果3个方面对碎石桩复合地基进行检测分析。  相似文献   

Modeling the 2D behavior of dry‐stone retaining walls by a fully discrete element method          下载免费PDF全文

James J. Oetomo  Eric Vincens  Fabian Dedecker  Jean‐Claude Morel 《国际地质力学数值与分析法杂志》2016,40(7):1099-1120

The dry‐stone retaining walls (DSRW) have been tipped as a promising solution for sustainable development. However, before recently, their behavior is relatively obscure. In this study, discrete element method (DEM) approach was applied to simulate the plane strain failure of these walls. A commercial DEM package (PFC2D™) was used throughout this study. The authors used a fully discrete approach; thus, both the wall and the backfill were modeled as discrete elements. The methodology for obtaining the micromechanical parameters was discussed in detail; this includes the three mechanical sub‐systems of DSRWs: wall, backfill and interface. The models were loaded progressively until failure, and then the results were compared with the full‐scale experimental results where the walls were loaded, respectively, with hydrostatic load and backfill. Despite its complexity and its intensive calculation time, DEM model can then be used to validate a more simplified approach. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Towards new applications of underwater photogrammetry for investigating coral reef morphology and habitat complexity in the Myeik Archipelago,Myanmar     

Martina Anelli  Tommaso Julitta  Luca Fallati  Paolo Galli  Micol Rossini  Roberto Colombo 《国际地球制图》2019,34(5):459-472

Photogrammetry represents a non-destructive, cost-effective tool for coral reef monitoring, able to integrate traditional remote sensing techniques and support researchers’ work. However, its application to submerged habitats is still in early stage. We present new ways to employ Structure from Motion techniques to infer properties of reef habitats. In particular, we propose the use of Digital Surface Models and Digital Terrain Models for assessing coral colonies extension and height and discriminating between seabed and coral cover. Such information can be coupled with digital rugosity estimates to improve habitat characterization. DTM, DSM and orthophotos were derived and used to compute a series of metrics like coral morphologies, reef topography, coral cover and structural complexity. We show the potentialities offered by underwater photogrammetry and derived products to provide useful basic information for marine habitat mapping, opening the possibility to extend these methods for large-scale assessment and monitoring of coral reefs.  相似文献