期刊文献+
共找到12篇文章
< 1 >
每页显示 20 50 100
Geophysical Significance of the Senegalo-Mali Discontinuity: Evidence from Secondary Structures, Kédougou-Kéniéba Inlier, Western Mali
1
作者 Mamadou Yossi Mahamadou Diallo +2 位作者 Mamoutou Ouattara Amadou Berthé Saidou Ly 《Open Journal of Geology》 CAS 2024年第10期943-962,共20页
The present study focuses on the analysis and description of lineaments interpreted as secondary structures to describe the nature of Senegalo Malian Discontinuity. These lineaments cross-cut the large north-south ori... The present study focuses on the analysis and description of lineaments interpreted as secondary structures to describe the nature of Senegalo Malian Discontinuity. These lineaments cross-cut the large north-south oriented transcurrent lithospheric structure known as the Senegalo Malian Discontinuity (SMD). Two lineaments were selected oriented NNE (N15˚ to N25˚), one at Dialafara and one at Sadiola. Four profiles on each lineament of these 2 zones, so that there were 2 on each side of the SMD. The ground data collected were processed using proper parameter and software. Some filters were applied to enhance the signal level. These ground data were later compared to the existing airborne magnetic data for consistency and accuracy using the upward continuation filter. The results show that the quality of ground data is good. In addition, the ground magnetic data show the presence of certain local anomalies that are not visible in the regional data. The analytical signal was also used to determine domain boundaries or possible contact zones. The contact zone can be highlighted on certain profiles such as L300 and L600. The study showed that the west and east sides of the SMD are not the same. Secondary structures become wide when approaching the SMD on both sides. They are also duplicated to the east of the SMD when we move progressively away. In the Dialafara area, the ground magnetic data intersect an interpreted fold. The results of this work confirm the presence of the secondary structures and their evolution in relation to the SMD. The relationships between the secondary structures in the Dailafara and Sadiola zones and their relations with the SMD are highlighted. The technique used in this study, is an important approach to better description and interpreting of regional structures using the secondary structures and proposing a structural model. 展开更多
关键词 Kédougou-Kéniéba Inlier Senegal Malian Discontinuity Secondary structures mapping Magnetic Data
下载PDF
Time-varying stiffness analysis of double-row tapered roller bearing based on the mapping structure of bearing stiffness matrix
2
作者 Di Yang Xi Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第11期89-100,共12页
Time-varying stiffness is one of the most important dynamic characteristics of rolling element bearings.The method of analyzing the elements in the bearing stiffness matrix is usually adopted to investigate the charac... Time-varying stiffness is one of the most important dynamic characteristics of rolling element bearings.The method of analyzing the elements in the bearing stiffness matrix is usually adopted to investigate the characteristics of bearing stiffness.Linear mapping structure of the bearing stiffness matrix is helpful to understand the varying compliance excitation and its influence on vibration transmission.In this study,a method to analyze the mapping structure of bearing stiffness matrix is proposed based on the singular value decomposition of block matrices in the stiffness matrix.Not only does this method have the advantages of coordinate transformation independence and unit independence,but also the analysis procedure involved is geometrically intuitive.The time-varying stiffness matrix of double-row tapered bearing is calculated and analyzed using the proposed method under two representative load cases.The principal stiffnesses and principal axes defined in the method together indicate the dominant and insignificant stiffness properties with the corresponding directions,and the vibration transmission properties are also revealed.Besides,the coupling behaviors between different shaft motions are found during the analysis of mapping structure.The mechanism of the generation of varying compliance excitation is also revealed. 展开更多
关键词 Rolling element bearing Time-varying stiffness matrix mapping structure Vibration transmission Varying compliance excitation
原文传递
PHYSICAL VALUE MAPPING ALGORITHM OF MESH IN FINE CAE ANALYSIS OF AUTOMOBILE BODY STRUCTURE 被引量:2
3
作者 Hu Ping Gong Kejia Bao Yidong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第3期338-341,共4页
A physical value mapping (PVM) algorithm based on finite element mesh from the stamped part in stamping process to the product is presented, In order to improve the efficiency of the PVM algorithm, a search way from... A physical value mapping (PVM) algorithm based on finite element mesh from the stamped part in stamping process to the product is presented, In order to improve the efficiency of the PVM algorithm, a search way from the mesh of the product to the mesh of the stamped part will be adopted. At the same time, the search process is divided into two steps: entire search (ES) and local search (LS), which improve the searching efficiency. The searching area is enlarged to avoid missing projection elements in ES process. An arc-length method is introduced in LS process. The validity is confirmed by the results of the complex industry-forming product. 展开更多
关键词 Fine CAE analysis of auto body structure Finite element mesh Arc method Physical value mapping
下载PDF
Using structure restoration maps to comprehensively identify potential faults and fractures in compressional structures 被引量:5
4
作者 欧成华 陈伟 李朝纯 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第3期677-684,共8页
Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished direct... Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional(3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques. 展开更多
关键词 potential fault and fracture comprehensive identification structure restoration maps 3D structural modeling compressional structures
下载PDF
An automated method for mapping physical soil and water conservation structures on cultivated land using GIS and remote sensing techniques 被引量:1
5
作者 Asnake MEKURIAW Andreas HEINIMANN +2 位作者 Gete ZELEKE Hans HURNI Kaspar HURNI 《Journal of Geographical Sciences》 SCIE CSCD 2017年第1期79-94,共16页
An efficient and reliable automated model that can map physical Soil and Water Conservation(SWC) structures on cultivated land was developed using very high spatial resolution imagery obtained from Google Earth and ... An efficient and reliable automated model that can map physical Soil and Water Conservation(SWC) structures on cultivated land was developed using very high spatial resolution imagery obtained from Google Earth and Arc GIS?ERDAS IMAGINE?and SDC Morphology Toolbox for MATLAB and statistical techniques. The model was developed using the following procedures:(1) a high-pass spatial filter algorithm was applied to detect linear features,(2) morphological processing was used to remove unwanted linear features,(3) the raster format was vectorized,(4) the vectorized linear features were split per hectare(ha) and each line was then classified according to its compass directionand(5) the sum of all vector lengths per class of direction per ha was calculated. Finallythe direction class with the greatest length was selected from each ha to predict the physical SWC structures. The model was calibrated and validated on the Ethiopian Highlands. The model correctly mapped 80% of the existing structures. The developed model was then tested at different sites with different topography. The results show that the developed model is feasible for automated mapping of physical SWC structures. Thereforethe model is useful for predicting and mapping physical SWC structures areas across diverse areas. 展开更多
关键词 physical SWC structure mapping automated mathematical morphology GIS and remote sensing
原文传递
Super-Resolution Image Reconstruction Based on an Improved Maximum a Posteriori Algorithm 被引量:1
6
作者 Fangbiao Li Xin He +2 位作者 Zhonghui Wei Zhiya Mu Muyu Li 《Journal of Beijing Institute of Technology》 EI CAS 2018年第2期237-240,共4页
A maximum a posteriori( MAP) algorithm is proposed to improve the accuracy of super resolution( SR) reconstruction in traditional methods. The algorithm applies both joints image registration and SR reconstruction... A maximum a posteriori( MAP) algorithm is proposed to improve the accuracy of super resolution( SR) reconstruction in traditional methods. The algorithm applies both joints image registration and SR reconstruction in the framework,but separates them in the process of iteratiion. Firstly,we estimate the shifting parameters through two lowresolution( LR) images and use the parameters to reconstruct initial HR images. Then,we update the shifting parameters using HR images. The aforementioned steps are repeated until the ideal HR images are obtained. The metrics such as PSNR and SSIM are used to fully evaluate the quality of the reconstructed image. Experimental results indicate that the proposed method can enhance image resolution efficiently. 展开更多
关键词 super-resolution(SR) maximum a posteriori(MAP) peak signal to noise ratio structure similarity
下载PDF
Assessment of Hydrocarbon Potential in Owem Field in Niger Delta, Nigeria 被引量:1
7
作者 Godwin Omokenu Emujakporue 《International Journal of Geosciences》 2016年第3期335-344,共10页
Seismic data were integrated with well log to define the subsurface geometry and hydrocarbon trapping potential of Owem field, onshore Niger Delta. The research methodology involved horizon and fault interpretation to... Seismic data were integrated with well log to define the subsurface geometry and hydrocarbon trapping potential of Owem field, onshore Niger Delta. The research methodology involved horizon and fault interpretation to produce subsurface structural map. Wireline logs signatures were employed to identify hydrocarbon bearing sand and compute reservoir petrophysical parameters for hydrocarbon reservoir analysis. Two horizons HA and HB were identified and mapped and a time structural map was produced. Two reservoirs R1 and R2 were delineated in the wells A and B. The computed petrophysical parameters for well A showed that the thickness of Reservoir R1 and R2 are 11.5 and 12.5 meters respectively while the porosity and hydrocarbon saturation varies between 0.16 - 0.24 and 0.6 - 0.8 respectively. Similarly the average thickness and porosity of R1 and R2 for well B is about 18.0 meters and 0.12 while the hydrocarbon saturation varies between 0.7 - 0.8. The integration of seismic and well logs data has proved to be a useful tool in the reservoir analysis of hydrocarbon. 展开更多
关键词 SEISMIC Well Logs Structural Map and Hydrocarbon
下载PDF
A Preliminary Report on Yong'anpu Tectonic Window in Suizhong County, Western Liaoning Province
8
作者 汪洋 姬广义 《Journal of China University of Geosciences》 SCIE CSCD 2006年第3期231-237,共7页
For understanding the Mesozoic tectonics of Yanshan (燕山 ) belt, the authors took geological mapping in the belt. A large-scale thrust structure was identified in Yonganpu (永安堡) area. in the western part of Su... For understanding the Mesozoic tectonics of Yanshan (燕山 ) belt, the authors took geological mapping in the belt. A large-scale thrust structure was identified in Yonganpu (永安堡) area. in the western part of Suizhong (绥中 ) County, Liaoning (辽宁 ) Province during our recent mapping in the Yanshan belt. The hanging wall of the thrust was composed of Archean gneiss and the overlying Early Cretaceous Zhangjiakou (张家口 ) Formation; meanwhile, the strongly ductile deformed volcanic rocks of Zhangjiakou Formation comprised the footwall in Yong'anpu tectonic window. This discovery indicates the existence of strongly contractional deformation in the Yanshan belt after the eruption of Early Cretaceous Zhangjiakou volcanic rocks. On the basis of mapping and research, it is concluded that the published official geological maps have failed to identify the major structural features of the Yanshan belt. 展开更多
关键词 thrust structure REFOLDING structural mapping Early Cretaceous Yonganpu.
下载PDF
CONCEPTUAL MODELING BASED ON LOGICAL EXPRESSION AND EVOLVEMENT
9
作者 YI Guodong ZHANG Shuyou TAN Jianrong JI Yangjian 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第1期64-68,共5页
Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions... Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions of the product conceptual design information, a fimction/logic/strucmre mapping model is set up. First, the fimction semantics is transformed into logical expressions through fimction/logic mapping. Second, the methods of logical evolvement are utilized to describe the fimction analysis, fimction/strucmre mapping and structure combination. Last, the logical structure scheme is transformed into geometrical sketch through logic/structure mapping. The conceptual design information and modeling process are described uniformly with logical methods in the model, and an effective method for computer aided conceptual design based on the model is implemented. 展开更多
关键词 Conceptual modeling Function/logic/structure mapping Logical evolvement
下载PDF
Continuous selections for pseudo-lower semicontinuous set-valued mappings on convex structure spaces and hyperspace contractibility
10
作者 Li, L Wu, CX 《Chinese Science Bulletin》 SCIE EI CAS 1997年第14期1230-1231,共2页
SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is... SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is introduced, and a convex structure of metric space is de-fined. A continuous selection theorem for pseudo-lower semicontinuity is given. This 展开更多
关键词 Continuous selections for pseudo-lower semicontinuous set-valued mappings on convex structure spaces and hyperspace contractibility
原文传递
High-Precision Structural Map of Southeast Cameroon Using Phase Filters on Potential Gravimetric Data
11
作者 Nzeuga Alain Rodrigue Bisse Salomon Bertrant +7 位作者 Amaya Adama Kenfack Fokem Alpha Baster Ngah Christian Gislain Leonel Ndjounguep Juscar Nanfa Tefak Fatoumata Maelle Ngoumou Paul Claude Assembe Stéphane Patrick Pokam Kengni Serge Hugues 《Open Journal of Earthquake Research》 2022年第4期89-107,共19页
The south-east of Cameroon encompasses a wide variety of geological structures among which we can cite the Congo Craton (CC), the Sanaga Fault (SF), the Yaoundé Domain, the Panafrican belt, the Protozoic series a... The south-east of Cameroon encompasses a wide variety of geological structures among which we can cite the Congo Craton (CC), the Sanaga Fault (SF), the Yaoundé Domain, the Panafrican belt, the Protozoic series and the Dja complex. The presence of all these structures justifies the great tectonic activity to which this area was subject from the rupture of Pangea to the creation of the different plates that exist today. In this work, we will bring out a high-resolution structural map of the study area by applying the qualitative analysis of the phase filters on 200,900 points of gravimetric data obtained from the combination of the XGM2016 and ETOPO1 models. Then, with these same data, we will bring out another structural map with the maxima method called Multi-Scale Horizontal Derivative of Vertical Derivative (MSHDVD) which will be compared to the first in order to show the limits of the MSHDVD method. To do this, we will first use the extension method to highlight the map of residual anomalies, then a combination of derivative, gradient and phase filters to highlight the geological structures responsible for fracturing in this area. Phase filters have the advantage that they make it possible to highlight all the geological edges responsible for the fracturing without taking into account the depth, while the MSHDVD method highlights the existing geological contacts (edges) at depths well defined by the examiner. The structural map obtained with the MSHDVD method shows that the major structural direction in this zone is W-E while that obtained from the interpretation of the phase filters is more precise and shows that the major structural direction in this area would be N-S and this result would be in perfect agreement with the tectonics of East Cameroon. 展开更多
关键词 GRAVIMETRY Potential Field Data Edge Detection Structural mapping Southeast Cameroon
下载PDF
A ubiquitous knowledgeable data representation model(UKRM) for three-dimensional geographic information systems(3D GIS) 被引量:2
12
作者 ZHANG ShuQing ZHOU ChengHu +1 位作者 ZHANG JunYan CHEN XiangCong 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第4期780-794,共15页
In the face of complicated, diversified three-dimensional world, the existing 3D GIS data models suffer from certain issues such as data incompatibility, insufficiency in data representation and representation types, ... In the face of complicated, diversified three-dimensional world, the existing 3D GIS data models suffer from certain issues such as data incompatibility, insufficiency in data representation and representation types, among others. It is often hard to meet the requirements of multiple application purposes(users) related to GIS spatial data management and data query and analysis, especially in the case of massive spatial objects. In this study, according to the habits of human thinking and recognition, discrete expressions(such as discrete curved surface(DCS), and discrete body(DB)) were integrated and two novel representation types(including function structure and mapping structure) were put forward. A flexible and extensible ubiquitous knowledgeable data representation model(UKRM) was then constructed, in which structurally heterogeneous multiple expressions(including boundary representation(B-rep), constructive solid geometry(CSG), functional/parameter representation, etc.) were normalized. GIS's ability in representing the massive, complicated and diversified 3D world was thus greatly enhanced. In addition, data reuse was realized, and the bridge linking static GIS to dynamic GIS was built up. Primary experimental results illustrated that UKRM was overwhelmingly superior to the current data models(e.g. IFC, City GML) in describing both regular and irregular spatial objects. 展开更多
关键词 Discrete curved surface(DCS) Discrete body(DB) Discrete structure Function structure mapping structure "2D/3D" integrated representation 3D GIS data model UKRM model
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部