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21.
叙永硫铁矿尾矿(高岭石粘土)的成分特征与利用研究   总被引:2,自引:0,他引:2  
以详细研究川南伤痛永黄铁矿尾矿(高岭石粘土)的物质成分特征及其中有害物质铁、钛的赋存状态为基础,对该尾矿(高岭石粘土)的开发利用作了部分试验研究,指出了该尾矿的开发利用方向及对矿区环境治理的意义。  相似文献   
22.
以高分辨率层序地层学理论为指导思想,通过地表露头、钻井岩芯、测井资料和地震剖面的综合研究,较为详细地分析了百色盆地子寅油田仑 35块下第三系那读组二段不同级次基准面旋回界面和湖泛面的成因类型及高分辨率层序地层学特征,从那二段湖底浊积扇-半深湖沉积体系中划分出 1个长期、2个中期、7~ 9个短期和 13~ 18个超短期旋回层序。在此基础上,分别讨论了各级次旋回层序的沉积序列、结构类型、叠加样式和分布模式,建立了以中期旋回层序为框架,以短期和超短期旋回层序为等时地层对比单元的地层格架,探讨了该理论体系及其技术方法在油气藏开发工程中的应用前景。  相似文献   
23.
大别山北部鹿吐石铺含石榴子石斜长角闪岩早期经历了榴辉岩相及随后的麻粒岩相退变质阶段,现主要表现为角闪岩相矿物组合特征。它的全岩+角闪石Rb-Sr等时线年龄为172±3Ma(I=0.706095),代表了角闪岩相阶段的退变质年龄。  相似文献   
24.
台湾9.21集集地震考察兼论强震发震断层   总被引:1,自引:0,他引:1       下载免费PDF全文
彭阜南  叶银灿 《地震地质》2004,26(4):576-585
1999年9月21日,台湾中部山麓带发生了M7.3的大地震,震源深度为8km,财产损失及人员伤亡是百年来台湾许多地震中损失及伤亡最大的1次,其震级也是台湾本岛陆上所发生的地震级别最大的。震源机制属低角度逆冲断层成因,余震在平面上围绕着北港高基底作半圆状分布,在垂向上,则分布在逆冲断层的上盘。与此相应,地面变形及上部结构物的破坏,以车笼埔发震断层上盘最为激烈,下盘几乎不受影响。此外,地震断裂的北端,水平位移量高达9.8m,垂直抬升达10m,比主震区要大;其地面加速度峰值,亦高达水平为502gal,垂直为519gal。这些特点表明,地震是受到地下深处侏罗型叠瓦状构造的控制。此外,3个诱发地震中心均受当地的地质构造与地貌条件的控制。文中还叙述了震害及工程结构物破坏的特点,尤其是水工结构物的震害  相似文献   
25.
Babadag, in the Denizli province of Turkey, is one of the oldest textile industry settlements. The town has suffered from a very slow slope movement for about 60 years. One-third of the population lives in the unstable area. The slope movement resulted in significant ground deformations and damage to buildings, roads and buried utilities, and negatively affects socioeconomic life in the town. This paper contributes to the understanding of the long-term plane shear slope movement at the town, analyzes the main causes of the movement, and describes the slope instability and its effects. Movement occurs at an annual rate of between 3.8 cm and 15 cm along weak bedding planes in the alternating marl and sandstone beds forming the slope. Engineering geological assessments based on movement, groundwater and rainfall monitoring data, laboratory testing, and stability analyses indicate the following main factors contributing to the movement: (a) the unfavorable orientations and low shear strength of the bedding planes, (b) variations in the groundwater table related to precipitation and waste water seeping from the damaged sewage system, and (c) undercutting at the toe of the slope by a creek. Particularly due to fluctuations in the groundwater table or variations in pore pressures, the slope movement exhibits increasing and decreasing rates of movement without catastrophic failure.  相似文献   
26.
用正斜压分解法,对1998年发生在鄂霍茨克海的阻高进行涡度和涡度拟以分析,结果发现:在阻高的不同阶段,正压涡度和正压涡度拟能远大于斜压涡度和斜压涡度拟能且在不同的阶段有着不同的演变过程;在阻塞的酝酿阶段正压和斜压涡度和涡度拟能不稳定增长,且向西南传播;在维持阶段,正压和斜压涡度和涡度拟能的增长达到最大值,阻塞形势建立并维持在阻塞区域内;在消亡阶段,正压涡度和涡度拟能与斜压涡度拟能则呈现出不稳定减少,向东南传播,阻塞崩溃,然后又增长。  相似文献   
27.
基于地球椭球体的缓冲区构建技术研究   总被引:9,自引:2,他引:9  
彭认灿  王家耀 《测绘学报》2002,31(3):270-273
从分析基于平面的缓冲区存在的不足入手,提出建立基于地球椭球体的点、线、面和复合要素缓冲区的设想,并详细论述了基于地球椭球体的点和线要素缓冲区构建技术。在此基础上,对构建面和复合要素的缓冲区作了扼要介绍。  相似文献   
28.
In this study, the zeta potential of montmorillonite in the presence of different chemical solutions was modeled by means of artificial neural networks (ANNs). Zeta potential of the montmorillonite was measured in the presence of salt cations, Na+, Li+ and Ca2+ and metals Zn2+, Pb2+, Cu2+, and Al3+ at different pH values, and observed values pointed to a different behavior for this mineral in the presence of salt and heavy metal cations. Artificial neural networks were successfully developed for the prediction of the zeta potential of montmorillonite in the presence of salt and heavy metal cations at different pH values and ionic strengths. Resulting zeta potential of montmorillonite shows different behavior in the presence of salt and heavy metal cations, and two ANN models were developed in order to be compared with experimental results. The ANNs results were found to be close to experimentally measured zeta potential values. The performance indices such as coefficient of determination, root mean square error, mean absolute error, and variance account for were used to control the performance of the prediction capacity of the models developed in this study. These indices obtained make it clear that the predictive models constructed are quite powerful. The constructed ANN models exhibited a high performance according to the performance indices. This performance has also shown that the ANNs seem to be a useful tool to minimize the uncertainties encountered during the soil engineering projects. For this reason, the use of ANNs may provide new approaches and methodologies.  相似文献   
29.
Prefetching is a process in which the necessary portion of data is predicted and loaded into memory beforehand. The increasing usage of geographic data in different types of applications has motivated the development of different prefetching techniques. Each prefetching technique serves a specific type of application, such as two-dimensional geographic information systems or three-dimensional visualization, and each one is crafted for the corresponding navigation patterns. However, as the boundary between these application types blurs, these techniques become insufficient for hybrid applications (such as digital moving maps), which embody various capabilities and navigation patterns. Therefore, a set of techniques should be used in combination to handle different prefetching requirements. In this study, a priority-based tile prefetching approach is proposed, which enables the ensemble usage of various techniques at the same time. The proposed approach manages these techniques dynamically through a fuzzy-logic-based inference engine to increase prefetching performance and to adapt to various exhibited behaviours. This engine performs adaptive decisions about the advantages of each technique according to their individual accuracy and activity level using fuzzy logic to determine how each prefetching technique performs. The results obtained from the experiments showed that up to a 25% increase in prefetching performance is achieved with the proposed ensemble usage over individual usage. A generic model for prefetching techniques was also developed and used to describe the given approach. Finally, a cross-platform software framework with four different prefetching techniques was developed to let other users utilize the proposed approach.  相似文献   
30.
一产于大别山北部铙钹寨面理化橄榄岩中的强变形榴辉岩的石榴子石具有退变质环带 ,表现为边部CaO含量下降和MnO含量升高 ,指示Ca和Mn在石榴子石具有较快的扩散速率。该榴辉岩中石榴子石 +绿辉石连线给出的Sm Nd年龄为 187± 5Ma ,显著小于大别山南部超高压榴辉岩及北部榴辉岩的Sm Nd年龄 (分别为 2 2 1± 5~ 2 2 8± 3Ma和 2 10± 6~ 2 14± 6Ma)。这一偏低的Sm Nd年龄可能是由于石榴子石退变质环带引起14 3 Nd/ 14 4 Nd降低所造成的。对该样品石榴子石、绿辉石和石英的δ18O测定表明 ,这些矿物之间的实测分馏值小于它们在 5 0 0~ 90 0℃条件下的平衡分馏值 ,从而证明它们之间存在氧同位素不平衡。榴辉岩中石榴子石的退变质环带也可造成绿辉石与石榴子石之间显著的Nd同位素和氧同位素不平衡现象。  相似文献   
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