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Non-iterative image feature matching algorithm based on reference point correspondences 被引量:1
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作者 张维中 张丽艳 +2 位作者 王小平 丁志安 周玲 《Journal of Southeast University(English Edition)》 EI CAS 2007年第2期190-195,共6页
Based on the coded and non-coded targets, the targets are extracted from the images according to their size, shape and intensity etc., and thus an improved method to identify the unique identity(D) of every coded ta... Based on the coded and non-coded targets, the targets are extracted from the images according to their size, shape and intensity etc., and thus an improved method to identify the unique identity(D) of every coded target is put forward and the non-coded and coded targets are classified. Moreover, the gray scale centroid algorithm is applied to obtain the subpixel location of both uncoded and coded targets. The initial matching of the uncoded target correspondences between an image pair is established according to similarity and compatibility, which are based on the ID correspondences of the coded targets. The outliers in the initial matching of the uncoded target are eliminated according to three rules to finally obtain the uncoded target correspondences. Practical examples show that the algorithm is rapid, robust and is of high precision and matching ratio. 展开更多
关键词 reference points detection coded and non-coded target SUBPIXEL gray scale centroid point correspondence
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Weakly δ-continuous Correspondences on Super-space 被引量:1
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作者 CHEN Gui-xiu 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第2期287-292,共6页
In the paper,we define weakly δ-continuous correspondences on super-space,On the basis of δ-open(closed) sets,θ-open(closed) sets and regular open(closed) sets in topological space,some equivalent conditions of thi... In the paper,we define weakly δ-continuous correspondences on super-space,On the basis of δ-open(closed) sets,θ-open(closed) sets and regular open(closed) sets in topological space,some equivalent conditions of this kind of correspondences are obtained,and some applications of subset nets and convergence nets are given. 展开更多
关键词 topological space super-space weakly δ-continuous correspondences subset nets
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Pragmatic Vagueness in Business Correspondences——A Perspective of PP
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作者 洪小丽 《海外英语》 2015年第19期209-211,共3页
Pragmatic vagueness is frequently used in business correspondences and it offers benefits to the addressers by making business letter more flexible,appropriate and polite.This paper focuses on the employment of vague ... Pragmatic vagueness is frequently used in business correspondences and it offers benefits to the addressers by making business letter more flexible,appropriate and polite.This paper focuses on the employment of vague language in international business correspondences based on the Politeness Principle.In this study,the pragmatic effect of vague language in business correspondence is illustrated and summarized as a motivated factor to better show politeness and respect.The use of vague language motivated by politeness consequently leads to a more smooth,successful and desired communication in business world. 展开更多
关键词 PRAGMATIC VAGUENESS BUSINESS CORRESPONDENCE POLITENESS PRINCIPLE functions
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EQUILIBIA OF NONCOMPACT GENERALIZED GAMES WITH CORRESPONDENCES WITHOUT OPEN LOWER SECTIONS 被引量:1
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作者 丁协平 《Acta Mathematica Scientia》 SCIE CSCD 1998年第1期79-89,共11页
The new classes of Fc-correspondences and Fc -majorised correspondenceswithout open lower sections is introduced. Some existence theorems of madximal elements ofthe Fc -correspondences and the Fc-majorized corresponde... The new classes of Fc-correspondences and Fc -majorised correspondenceswithout open lower sections is introduced. Some existence theorems of madximal elements ofthe Fc -correspondences and the Fc-majorized correspondences defined on noncompactset in topological vector spaces are obtained. As applications, some existence theoremsof equilibrium points for one-person games, qualitative games and generalized games withthe Fc -majorized correspondences devined on noncompact strategy sets in topologicalvector spaces are also given. These theorems improve and generalize several known resultsin recent literature. 展开更多
关键词 Generalized games Fc-majorized correspondence transfer compactly openvalued EQUILIBRIUM
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Point Correspondences between <i>N</i>+ 1 Hypersurfaces of Projective Spaces and (<i>N</i>+ 1)-Webs
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作者 V. S. Bolodurin 《Applied Mathematics》 2013年第11期14-22,共9页
For a correspondence in question we establish a sequence of fundamental geometrical objects of the correspondence and find invariant normalizations of the first and second orders of all hupersurfaces under the corresp... For a correspondence in question we establish a sequence of fundamental geometrical objects of the correspondence and find invariant normalizations of the first and second orders of all hupersurfaces under the correspondence. We single out main tensors of the correspondence and establish a connection between the geometry of point correspondences between n + 1 hypersurfaces of projective spaces and the theory of multidimensional (n + 1)-webs. 展开更多
关键词 Hupersurface Point CORRESPONDENCE Invariant Normalization Multidimensional (n + 1)-Webs
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The Stylistic Features of Business English Correspondences and the Cultivation of Business English Competence
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作者 朱彦臻 肖家燕 《海外英语》 2017年第17期192-195,212,共5页
Nowadays, with the background of economic globalization, shopping modes like e Bay, Ali Express and Amazon are popular among the public. Business English that plays an increasingly important role in international trad... Nowadays, with the background of economic globalization, shopping modes like e Bay, Ali Express and Amazon are popular among the public. Business English that plays an increasingly important role in international trades is widely applied to commercial activities. However, because of insufficient practical experience, improper use of stylistics and interference of first language, sometimes it is difficult for students in school to have good command of business English correspondence. This dissertation has suggested learners several ways to improve their competence in international communications and the teaching and learning efficiency, by analyzing the stylistic features of business English correspondences and the problems collecting from the learners on the basis of the data of questionnaires. 展开更多
关键词 business English correspondence business English stylistic features international communication
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Topological phases and edge modes of an uneven ladder
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作者 商文创 韩熠宁 +1 位作者 Shimpei Endo 高超 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期154-168,共15页
We investigate the topological properties of a two-chain quantum ladder with uneven legs,i.e.,the two chains differ in their periods by a factor of 2.Such an uneven ladder presents rich band structures classified by t... We investigate the topological properties of a two-chain quantum ladder with uneven legs,i.e.,the two chains differ in their periods by a factor of 2.Such an uneven ladder presents rich band structures classified by the closure of either direct or indirect bandgaps.It also provides opportunities to explore fundamental concepts concerning band topology and edge modes,including the difference of intracellular and intercellular Zak phases,and the role of the inversion symmetry(IS).We calculate the Zak phases of the two kinds and find excellent agreement with the dipole moment and extra charge accumulation.We also find that configurations with IS feature a pair of degenerate two-side edge modes emerging as the closure of the direct bandgap,while configurations without IS feature one-side edge modes emerging as not only the closure of both direct and indirect bandgaps but also within the band continuum.Furthermore,by projecting to the two sublattices,we find that the effective Bloch Hamiltonian corresponds to that of a generalized Su–Schrieffer–Heeger model or the Rice–Mele model whose hopping amplitudes depend on the quasimomentum.In this way,the topological phases can be efficiently extracted through winding numbers.We propose that uneven ladders can be realized by spin-dependent optical lattices and their rich topological characteristics can be examined by near future experiments. 展开更多
关键词 ladder model symmetry-protected topological phase topological invariant bulk-boundary correspondence
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On calculating glacial isostatic adjustment
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作者 L.M.Cathles 《Geodesy and Geodynamics》 EI CSCD 2024年第5期441-452,共12页
Modeling the earth's fluid and elastic response to the melting of the glaciers of the last ice age is the most direct way to infer the earth's radial viscosity profile.Here,we compare two methods for calculati... Modeling the earth's fluid and elastic response to the melting of the glaciers of the last ice age is the most direct way to infer the earth's radial viscosity profile.Here,we compare two methods for calculating the viscoelastic response to surface loading.In one,the elastic equation of motion is converted to a viscoelastic equation using the Correspondence Principle.In the other,elastic deformation is added to the viscous flow as isostatic adjustment proceeds.The two modeling methods predict adjustment histories that are different enough to potentially impact the interpretation of the observed glacial isostatic adjustment(GIA).The differences arise from buoyancy and whether fluid displacements are subjected to hydrostatic pre-stress.The methods agree if they use the same equations and boundary conditions.The origin of the differences is determined by varying the boundary conditions and pre-stress application. 展开更多
关键词 Glacial isostatic adjustment Viscoelastic normal modes Hydrostatic pre-stress Elastic buoyancy Correspondence principle
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Selective sampling with Gromov–Hausdorff metric:Efficient dense-shape correspondence via Confidence-based sample consensus
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作者 Dvir GINZBURG Dan RAVIV 《虚拟现实与智能硬件(中英文)》 EI 2024年第1期30-42,共13页
Background Functional mapping, despite its proven efficiency, suffers from a “chicken or egg” scenario, in that, poor spatial features lead to inadequate spectral alignment and vice versa during training, often resu... Background Functional mapping, despite its proven efficiency, suffers from a “chicken or egg” scenario, in that, poor spatial features lead to inadequate spectral alignment and vice versa during training, often resulting in slow convergence, high computational costs, and learning failures, particularly when small datasets are used. Methods A novel method is presented for dense-shape correspondence, whereby the spatial information transformed by neural networks is combined with the projections onto spectral maps to overcome the “chicken or egg” challenge by selectively sampling only points with high confidence in their alignment. These points then contribute to the alignment and spectral loss terms, boosting training, and accelerating convergence by a factor of five. To ensure full unsupervised learning, the Gromov–Hausdorff distance metric was used to select the points with the maximal alignment score displaying most confidence. Results The effectiveness of the proposed approach was demonstrated on several benchmark datasets, whereby results were reported as superior to those of spectral and spatial-based methods. Conclusions The proposed method provides a promising new approach to dense-shape correspondence, addressing the key challenges in the field and offering significant advantages over the current methods, including faster convergence, improved accuracy, and reduced computational costs. 展开更多
关键词 Dense-shape correspondence Spatial information Neural networks Spectral maps Selective sampling
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Evaluation of Soil Fertility Quality and Environmental Driving Factors in Different Soil Types of Artificial Forests
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作者 Songyu YU Zhenhui LIAO +3 位作者 Mingwu YANG Ronghui HU Yuanyuan SHI Junyu ZHAO 《Meteorological and Environmental Research》 2024年第2期64-70,共7页
The aim was to clarify the environmental driving factors of soil fertility indicators in artificial forests of Guangxi and comprehensively evaluate the soil fertility level.By collecting data on the current status of ... The aim was to clarify the environmental driving factors of soil fertility indicators in artificial forests of Guangxi and comprehensively evaluate the soil fertility level.By collecting data on the current status of soil in artificial forests,the spatial distribution of major soil fertility indicators was analyzed,and the distribution map of the fertility index of artificial forests in the entire region and the comprehensive fertility index of artificial forests of different soil types were obtained.Canonical correspondence analysis method was used to analyze soil fertility indicators and environmental factors,and the environmental driving factors of soil fertility indicators for artificial forests of the main soil types in Guangxi were obtained.The results showed that over 90%of the soil fertility index of artificial forests in the entire region was between 0.20 and 0.50.The order of soil fertility index of different soil types of artificial forests from high to low was yellow brown soil>yellow red soil>yellow soil>red soil>limestone soil>latosolic red soil>laterite.In artificial forests of latosolic red soil,the correlation between soil alkaline nitrogen and organic matter,annual average temperature was high,while the correlation between soil available phosphorus and organic matter,pH was high,and the correlation between soil available potassium and environmental factors such as slope,altitude,rainfall,accumulated temperature,and slope aspect was high.In artificial forests of red soil,the correlation between soil alkaline nitrogen and slope,altitude was high,while the correlation between soil available phosphorus and accumulated temperature,rainfall was high,and the correlation between soil available potassium and pH was high.In artificial forests of limestone soil,there was a high correlation between soil alkaline nitrogen and slope,organic matter,a high correlation between soil available phosphorus and accumulated temperature,rainfall,and a high correlation between soil available potassium and pH. 展开更多
关键词 Soil fertility index GIS Forest soil Canonical correspondence analysis
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The Deconvolution Method for Obtaining Correspondence in Data-Independent Acquisition Mass Spectrometry Data
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作者 Mingming Lyu Xinye Bian Changjiu He 《Journal of Computer and Communications》 2024年第2期11-25,共15页
Although data-independent acquisition (DIA) shows powerful potential in achieving comprehensive peptide information acquisition, the difficulty in determining the precursor m/z and distinguishing fragment ions has pos... Although data-independent acquisition (DIA) shows powerful potential in achieving comprehensive peptide information acquisition, the difficulty in determining the precursor m/z and distinguishing fragment ions has posed challenges in DIA data analysis. To address this challenge, a common approach is to recover the correspondence between precursor ions and fragment ions, followed by peptide identification using traditional data-dependent acquisition (DDA) database searching. In this study, we propose a cosine similarity-based deconvolution method that rapidly establishes the correspondence between chromatographic profiles of precursor ions and fragment ions through matrix calculations. Experimental results demonstrate that our method, referred to as CosDIA, yields a peptide identification count close to that of DIA-umpire. However, compared to DIA-umpire, we can establish the correspondence between original MS/MS spectra and pseudo-MS/MS spectra. Furthermore, compared to the CorrDIA method, our approach achieves higher efficiency in terms of time, reducing the time cost of the analysis process. These results highlight the potential advantages of the CosDIA method in DIA data analysis, providing a powerful tool and method for large-scale proteomics research. 展开更多
关键词 MS/MS Spectra XICs CORRESPONDENCE Matrix Isotopic Peak Cluster
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Special Relativity’s “Newtonization” in Complex “Para-Space”: The Two Theories Equivalence Question
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作者 Jerzy K. Filus 《Journal of Applied Mathematics and Physics》 2024年第7期2421-2451,共31页
Complex model, say C3, of “para-space” as alternative to the real M4 Minkowski space-time for both relativistic and classical mechanics was shortly introduced as reference to our previous works on that subject. The ... Complex model, say C3, of “para-space” as alternative to the real M4 Minkowski space-time for both relativistic and classical mechanics was shortly introduced as reference to our previous works on that subject. The actual aim, however, is an additional analysis of the physical and para-physical phenomena’ behavior as we formally transport observable mechanical phenomena [motion] to non-real interior of the complex domain. As it turns out, such procedure, when properly set, corresponds to transition from relativistic to more classic (or, possibly, just classic) kind of the motion. This procedure, we call the “Newtonization of relativistic physical quantities and phenomena”, first of all, includes the mechanical motion’s characteristics in the C3. The algebraic structure of vector spaces was imposed and analyzed on both: the set of all relativistic velocities and on the set of the corresponding to them “Galilean” velocities. The key point of the analysis is realization that, as a matter of fact, the relativistic theory and the classical are equivalent at least as for the kinematics. This conclusion follows the fact that the two defined structures of topological vector spaces i.e., the structure imposed on sets of all relativistic velocities and the structure on set of all “Galilean” velocities, are both diffeomorphic in their topological parts and are isomorphic as the vector spaces. As for the relativistic theory, the two approaches: the hyperbolic (“classical” SR) with its four-vector formalism and Euclidean, where SR is modeled by the complex para-space C3, were analyzed and compared. 展开更多
关键词 Special Relativity’s Hyperbolic Versus Circular Versions Galilean Kinematics Partial Equivalence of SR and Newton’s Theories Algebra of Relativistic and the Corresponding Galilean Velocities
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Complex Correspondences in Straight Line Stereo Matching
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作者 WANG Jiyang WEN Gongjian LI Deren 《Geo-Spatial Information Science》 2010年第2期103-110,共8页
Partial occlusion and fragmented lines will result in the various cases of straight line correspondences, such as one-to-one, one-to-many or many-to-many ones. However, the complex correspondences, such as one-to-many... Partial occlusion and fragmented lines will result in the various cases of straight line correspondences, such as one-to-one, one-to-many or many-to-many ones. However, the complex correspondences, such as one-to-many and many-to-many ones, are usually ignored or cannot be established completely in the existing methods. Here, the essence of the complex correspondences will be analyzed. Based on the two characteristics of a straight line, which are introduced by regarding a straight line as a set of collinear points, the compatibility between the complex correspondences and the uniqueness constraint of point correspondence is proved and a new uniqueness constraint of correspondence for matching lines is proposed. Based on the analysis of the complex correspondences, a new concept of line feature group is defined to describe a set of integral correspondences among straight line features from different images and then a new algorithm for establishing all the correspondences completely is described simply. The experimental results with real stereo images illustrate that the complex correspondences among straight lines are actual cases and can be established effectively. 展开更多
关键词 straight line stereo matching OCCLUSION fragmentation complex correspondence uniqueness constraint feature group
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Robot Self-Location by Line Correspondences
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作者 胡占义 雷成 徐孔达 《Journal of Computer Science & Technology》 SCIE EI CSCD 2001年第2期97-113,共17页
This paper thoroughly investigates the problem of robot self-location by line correspondences. The original contributions are three-fold: (1) Obtain the necessary and sufficient condition to determine linearly the rob... This paper thoroughly investigates the problem of robot self-location by line correspondences. The original contributions are three-fold: (1) Obtain the necessary and sufficient condition to determine linearly the robot's pose by two line correspondences. (2) Show that if the space lines are vertical ones, it is impossible to determine linearly the robot's pose no matter how many line correspondences we have, and the minimum number of line correspondences is 3 to determine uniquely (but non-linearly) the robot's pose. (3) Show that if the space lines are horizontal ones, the minimum number of line correspondences is 3 for linear determination and 2 for non-linear determination of the robot's pose. 展开更多
关键词 robot self-location visual guided navigation line correspondence projection plane line mapping constraint
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Corresponding Prime Number Distribution Equation 被引量:1
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作者 Dan Liu Chenglong Liu 《Journal of Applied Mathematics and Physics》 2023年第11期3354-3365,共12页
The conjecture of twin prime numbers is a mathematical problem. Proving the twin prime conjecture using traditional modern number theory is extremely profound and complex. We propose an elementary research method for ... The conjecture of twin prime numbers is a mathematical problem. Proving the twin prime conjecture using traditional modern number theory is extremely profound and complex. We propose an elementary research method for corresponding prime number, proved that the conjecture of twin prime numbers and obtain the corresponding prime distribution equation. According to the distribution rate of corresponding prime numbers, the distribution pattern of twin prime numbers was proved the distribution rate theorem. This is the distribution rate of prime numbers corresponding to composite numbers, which approaches the distribution rate of prime numbers corresponding to integers. Based on the corresponding prime distribution equation, obtain the twin prime inequality function. Then, the formula for calculating twin prime numbers was discussed. There is also the Hardy Littlewood conjecture. This provides a practical and feasible approach for studying the distribution of twin prime numbers. 展开更多
关键词 Prime Number Composite Number Twin Prime Numbers Corresponding Prime Distribution Equation Twin Prime Inequality Function
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Dual Branch PnP Based Network for Monocular 6D Pose Estimation
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作者 Jia-Yu Liang Hong-Bo Zhang +2 位作者 Qing Lei Ji-Xiang Du Tian-Liang Lin 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期3243-3256,共14页
Monocular 6D pose estimation is a functional task in the field of com-puter vision and robotics.In recent years,2D-3D correspondence-based methods have achieved improved performance in multiview and depth data-based s... Monocular 6D pose estimation is a functional task in the field of com-puter vision and robotics.In recent years,2D-3D correspondence-based methods have achieved improved performance in multiview and depth data-based scenes.However,for monocular 6D pose estimation,these methods are affected by the prediction results of the 2D-3D correspondences and the robustness of the per-spective-n-point(PnP)algorithm.There is still a difference in the distance from the expected estimation effect.To obtain a more effective feature representation result,edge enhancement is proposed to increase the shape information of the object by analyzing the influence of inaccurate 2D-3D matching on 6D pose regression and comparing the effectiveness of the intermediate representation.Furthermore,although the transformation matrix is composed of rotation and translation matrices from 3D model points to 2D pixel points,the two variables are essentially different and the same network cannot be used for both variables in the regression process.Therefore,to improve the effectiveness of the PnP algo-rithm,this paper designs a dual-branch PnP network to predict rotation and trans-lation information.Finally,the proposed method is verified on the public LM,LM-O and YCB-Video datasets.The ADD(S)values of the proposed method are 94.2 and 62.84 on the LM and LM-O datasets,respectively.The AUC of ADD(-S)value on YCB-Video is 81.1.These experimental results show that the performance of the proposed method is superior to that of similar methods. 展开更多
关键词 6D pose monocular RGB edge enhancement dual-branch PnP 2D-3D correspondence
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Characterization of Gold Bearing Placers and Associated Minerals in the Elogo Region (North-West Congo Republic)
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作者 Noël Watha-Ndoudy Prince Espoire Wamene Okoumel +7 位作者 Timothée Miyouna Renaud Hermann Assouka Mpika Eddy Guembou Massala Guichel Souaty Mibantsa Kester Mayenga Joseph Victor Hell Boniface Kankeu Florent Boudzoumou 《Open Journal of Geology》 CAS 2023年第5期287-305,共19页
The Elogo region has been subjected to craft industry and semi-industrial mining for gold-bearing placers, since the colonial times. It is actually undergoing an intensive exploration for a primary gold deposit. The g... The Elogo region has been subjected to craft industry and semi-industrial mining for gold-bearing placers, since the colonial times. It is actually undergoing an intensive exploration for a primary gold deposit. The goal of this study is to contribute to the exploration of the primary gold deposit in the Elogo Region (North-West of Congo Republic). The methodology consisted of characterization of placers deposits by their lithology, mineralogy and the gold grains shape, in order to constrain the source of gold with the respect to the local geology. The results obtained show that alluviums are polygenic and yields seventeen mineral species composed of zircon, olivine, magnetite, ilmenite, gold, garnet, rutile, coltan, cassiterite, monazite, apatite, amphibole, tourmaline, pyrite, limonite, chromite, and amphibole. The morphoscopy of gold grain shows single grains and grains with quartz inclusions that suggest their relationship with quartz veins. The gold grains are flattened, sub-flattened, and rounded. The northern region of Elogo characterized by a dominance of coarser quartz-included gold grains indicates a proximal proparte origin (less than 50 m), while the southern region, showing less coarse and more evolved grains with choc marks, appears to be associated with a distal pro-parte origin (more than 300 m). The multivariate statistical analysis shows seven classes of samples corresponding to the mineralogical paragenesis suggesting various sources, consisting of high-grade metamorphic, granitoids, pegmatites, basic and ultrabasic rocks, and BIFs that provided minerals to the placers. Gold mainly comes from hydrothermal quartz veins and probably from the peptization of gold from the weathering of sulfides occurring in the BIF. In the Elogo region, gold exploration for primary deposits should look for and follow the hydrothermal system developed in this region. Chemical analysis for the gold grains and associated minerals is necessary to better guide the proposed geochemical prospecting. 展开更多
关键词 Auriferous Placers Associated Minerals Correspondence Factor Analysis Principal Component Analysis Elogo Gold Exploration
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African Memoirs and Cultural Representations
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作者 TOYIN FALOLA 《ChinAfrica》 2023年第2期64-64,共1页
Oral traditions and creative oratures have been celebrated in African studies over the years,specifically from the 1950s,as the most important and viable correspondence,aside from material artifacts,between social“ar... Oral traditions and creative oratures have been celebrated in African studies over the years,specifically from the 1950s,as the most important and viable correspondence,aside from material artifacts,between social“archaeologists”attempting to penetrate the African preliterate past and the social-political and economic productions of that same past. 展开更多
关键词 AFRICAN viable CORRESPONDENCE
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The Factors Shaping Synonymous Codon Usage in the Genome of Burkholderia mallei 被引量:4
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作者 赵胜 张琴 +2 位作者 陈智华 赵益新 钟金城 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第4期362-372,共11页
Burkholderia mallei is regarded as a potential biological weapon by the Centers for Disease Control and Prevention. In this study, the main factors shaping codon usage in the genome of B. mallei ATCC 23344 were firstl... Burkholderia mallei is regarded as a potential biological weapon by the Centers for Disease Control and Prevention. In this study, the main factors shaping codon usage in the genome of B. mallei ATCC 23344 were firstly reported. The results showed that the primary trend in codon usage variation in the B. mallei is due to translational selection; while compositional mutation bias is relatively the weaker influence and the hydrophobicity of each protein and gene length are only the minor influences. At the same time, 21 codons defined firstly as 'optimal codons' might provide more useful information for the expression of target genes and development of a vaccine to prevent glanders. 展开更多
关键词 Burkholderia mallei ATCC 23344 codon usage correspondence analysis
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Spatial and environmental effects on plant communities in the Yellow River Delta, Eastern China 被引量:8
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作者 宋创业 刘高焕 刘庆生 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第2期117-122,I0002,共7页
Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses (DCCAs) and a two-way indicator species analysis (TWINSPAN). The distributi... Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses (DCCAs) and a two-way indicator species analysis (TWINSPAN). The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling methods. Results showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix chinensis. The vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble potassium. Among the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2% of total variation. Spatial variation and spatial-structured environmental variation explain 11.8%, and 2.2%, respectively. Remained 40.8% of undetermined variation is attributed to biological and stochastic factors. 展开更多
关键词 detrended canonical correspondence analyses environmental factors plant communities spatial factors Yellow River Delta two-way indicator species analysis
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