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排序方式: 共有273条查询结果,搜索用时 15 毫秒
1.
陀螺经纬仪的读数方法比较研究   总被引:2,自引:0,他引:2  
介绍了陀螺定向测量中三种不同的数据采集方法,分析了各种方法的优缺点。作者认为传感器采集数据自动化程度高,精度高,特别是运用位置敏感探测器(PSD)采样数据量大,具有一定的抗干扰能力,但在运用传感器采样时必须注意克服非线性误差。  相似文献   
2.
针对MODIS(Moderate Resolution Imaging Spectroradiometer)影像数据海量并具有重要研究价值的特点,研究MODIS影像的无损压缩算法。采用最佳线性预测方法,通过波段相关性排序确定波段最优预测顺序,并自适应计算"预测波段"与"当前波段"的二阶最佳预测器系数,减少谱间冗余;以多级树集合分裂树(Set Partitioning In Hierarchical Trees,SPIHT)编码算法降低谱内相关。为确保无损压缩,对线性预测系数进行最佳逼近取整操作,并采用基于提升格式的D5/3整数小波变换。实验结果表明本文提出的算法在压缩比上性能较3DSPIHT等算法突出。  相似文献   
3.
济阳坳陷孤南洼陷低熟油成藏特征   总被引:8,自引:0,他引:8  
陈建渝  田波等 《地球科学》2002,27(4):435-440
孤南洼陷具有丰富的低熟油资源,低熟油中的生物标志物以高伽玛蜡烷含量,植烷优势,低成熟度为特征。下第三系沙一段是低熟油的源岩,其岩性为富含藻类有机质的油页岩,油泥岩,低熟油在平面上环生烃洼陷分布,剖面上层位集中在沙二-沙一段,断层控制了低熟油的运移距离和聚集层位,低熟油的成藏模式有3种,即自源侧向运移聚集成藏,自源断层垂向运聚成茂混合运取成藏模式。孤南洼陷低熟油盆地内部以侧向运移,侧向充注入岩性-断块圈闭为主,形成单源油藏。在断藏带原油是以垂向运移及垂向充注断块圈闭为主,形成混源油藏。  相似文献   
4.
Fracturing and frictional sliding of quartz and granite under dry condition generates fractoluminescence, charged particle emission and electromagnetic radiation. Various kinds of experiments indicate that surface charge density on fracture or frictional slip surface of quartz and granite is 10−4 to 10−2 C/m2 which is larger than bound charges induced by the disappearance of piezoelectricity due to the release of stress. Hole and electron trapping centers, which is found in semiconductor devices with the Si–SiO2 system, are causes of surface charging on fracture or frictional slip surface of quartz crystal. The quantity of the surface charge is enough to cause corona discharge that can generate earthquake lights. The mechanism considering the hole and electron trapping centers has a probability to explain why non-piezoelectric minerals or rocks generate electromagnetic phenomena. It can be one of origins of seismo-electromagnetic phenomena (SEP).  相似文献   
5.
充电激发极化法在金属矿上的应用   总被引:1,自引:0,他引:1  
杨立功 《矿产与地质》2003,17(1):34-36,26
充电激发极化法是矿山物探的一种主要方法,其兼有充电法与激发极化法的特点,可利用已有的工程,最大限度地了解地下三度空间地球物理场的分布情况,解决地质问题。概述了其理论基础和方法技术,并列举了该方法在多个金属矿上的应用实例。  相似文献   
6.
地下物探在有色金属矿山寻找隐伏矿体的应用   总被引:4,自引:0,他引:4  
介绍了地下地球物理找矿方法在几个典型有色金属矿山进行生产找矿的实例,根据对不同深度的面积工作获得的系列直流电法、电磁法异常的计算分析,分别提出解释推断及施工建议,经工程验证,取得了显著的地质效果。  相似文献   
7.
 As part of a wider study of the nature and origins of cation order–disorder in micas, a variety of computational techniques have been used to investigate the nature of tetrahedral and octahedral ordering in phengite, K2 [6](Al3Mg)[4](Si7Al)O20(OH)4. Values of the atomic exchange interaction parameters J n used to model the energies of order–disorder were calculated. Both tetrahedral Al–Si and octahedral Al–Mg ordering were studied and hence three types of interaction parameter were necessary: for T–T, O–O and T–O interactions (where T denotes tetrahedral sites and O denotes octahedral sites). Values for the T–T and O–O interactions were taken from results on other systems, whilst we calculated new values for the T–O interactions. We have demonstrated that modelling the octahedral and tetrahedral sheets alone and independently produces different results from modelling a whole T–O–T layer, hence justifying the inclusion of the T–O interactions. Simulations of a whole T–O–T layer of phengite indicated the presence of short-range order, but no long-range order was observed. Received: 8 August 2002 / Accepted: 14 February 2003 Acknowledgements The authors are grateful to EPSRC (EJP) and the Royal Society (CIS) for financial support. Monte Carlo simulations were performed on the Mineral Physics Group's Beowulf cluster and the University of Cambridge's High Performance Computing Facility.  相似文献   
8.
地震勘探中的炸药震源药量理论与实验分析   总被引:5,自引:1,他引:5  
炸药由于具有良好的脉冲特性及高能量的特点而作为地震勘探中的主要震源,就炸药本身来说,在地震勘探中药量、井深等参数的选取对激发能量和激发频率有很大的影响。为此,本文运用炸药爆炸理论,从炸药作功角度来加以论述,并通过理论和实验分析得出选取一个最佳的药量和井深激发,既能提高炸药作功能力,又能增强激发能量,从而激发强能量的高频震源子波,达到指导野外地震采集和节约经济成本的目的。  相似文献   
9.
 The prediction of the hydrocarbon potential of a specific trap or of a number of specific traps (venture), referred to herein as prospect appraisal, concerns a probabilistic exercise based on the quantification of geology in terms of structural closure, reservoir quality, hydrocarbon charge, and the retention potential of the seal. Its objectives include: (a) prediction of the hydrocarbon volumes that could be present in the trap from an analysis of its geologic attributes; (b) the amount of uncertainty introduced in the volumetric prediction by the uncertainties in the subsurface geology; (c) the risk that one or more of the essential attributes of the prospect are underdeveloped and recoverable reserves are absent. The uncertainty of the geologic input requires a probabilistic approach, for which the Monte Carlo procedure is well suited. Prospect appraisal forms the basis for decision-making in oil exploration and development and, therefore, should be reliable, consistent, and auditable. This requires the use of a consistent methodology, the development of reliable models to quantify the geologic processes involved, and the collection of comprehensive and relational databases for the many geologic variables. As a result of data availability, uncertainty and risk tend to increase strongly from mature, producing basins to areas of frontier exploration. This may complicate management of exploration portfolios. Received: 1 July 1996/Accepted: 25 November 1996  相似文献   
10.
Electric field effect on animals has been studied to investigate its relation with seismic anomalous animal behaviors(SAABs)in China.Freshwater eel,crucian carp,catfish,and soft-shelled turtle responded to the threshold electric field of 1-10 V/m,while duck,goose,cat,sheep,pig,dog,and chicken all responded to the ground electric field of about tens of V/m,depending on the species as well as on individuals.Most of the behaviors caused by electric field were similar to those reported as SAABs such as alignment,sudden movement,panic,and convulsion.The intensity of electric field due to a major earthquake would have been over these threshold values.Numerical estimation based on an electromagnetic model of a fault has been made to induce SAABs as electric shocks to pulsed electric fields in electro-physiology.The seismic electric signals(SES)intensity might be estimated from the observation of SAABs.  相似文献   
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