Results 181 to 190 of about 2,982,469 (235)
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High-Resolution Density Gradient Sedimentation Analysis
Science, 1960The principle of stability for a sample layered in a density-gradient liquid column is discussed, and a method for separating ribonucleoprotein particles by means of sedimentation in the ultracentrifuge is described.
Britten, R. J., Roberts, R. B.
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Gradient Analysis of Ecosystems
1991Comparative studies have been useful for understanding the biogeochemistry of terrestrial ecosystems, particularly where comparisons can be carried out along gradients of an underlying controlling factor. Examples of the application of gradient approaches include the analysis of state factors developed by Hans Jenny, analyses of the regulation of ...
Peter M. Vitousek, Pamela A. Matson
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Stereological analysis and modelling of gradient structures
Journal of Microscopy, 1999Gradient structures are inhomogeneous along a particular gradient direction but homogeneous perpendicular to that direction. Consequently, structural parameters such as volume fraction or surface area density are local characteristics which depend on the ‘vertical’ coordinate with respect to the ‘vertical’ gradient axis.Analogously, models for gradient
U. Hahn +4 more
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Computational post failure analysis with a second gradient theory
European Journal of Environmental and Civil Engineering, 2010This article presents a theory of Gradient Elastoplasticity for strain-softening materials, in which internal length scales are present in both the elastic and the elastoplastic regime. A numerical discretisation based on the displacement formulation and a C1 finite element is used.
Zervos, A. +3 more
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1978
Community samples (‘Aufnahmen,’ releves) are the essential working material for gradient analysis. The procedures to be described below can (with some limitations) be applied to any kind of community sample. Thus one can, in principle, use for gradient analysis samples of the vascular plants of forests, lichens on the barks of trees, singing bird pairs
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Community samples (‘Aufnahmen,’ releves) are the essential working material for gradient analysis. The procedures to be described below can (with some limitations) be applied to any kind of community sample. Thus one can, in principle, use for gradient analysis samples of the vascular plants of forests, lichens on the barks of trees, singing bird pairs
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Gradient-based direct normal-mode analysis
The Journal of Chemical Physics, 2005A formulation of a direct, iterative method for obtaining the lowest eigenvalues and eigenvectors of a Hessian matrix is presented. Similar to the iterative schemes in electronic structure configuration interaction calculations (methods due to Lanczos, Davidson, and others), the mass-weighted Hessian matrix K is not constructed explicitly; instead, its
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1991
This chapter describes one way of recovering depth information from a sequence of grey-scale images. This technique, called the Intensity Gradient Analysis (IGA) algorithm, is based on the ideas presented in the previous chapter. As one might well infer, IGA uses intensity gradients to determine when a fixed image displacement occurs.
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This chapter describes one way of recovering depth information from a sequence of grey-scale images. This technique, called the Intensity Gradient Analysis (IGA) algorithm, is based on the ideas presented in the previous chapter. As one might well infer, IGA uses intensity gradients to determine when a fixed image displacement occurs.
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Gradient Analysis in Swamp Forests
Nature, 1962DURING 1960 and 1961 we studied periodically flooded wetlands dominated by the trees Larix laricina, Thuja occidentalis, and Ulmus americana along transects from lake margins to the upland in the Rideau Lakes Region of Ontario. This vegetation shows distinct belts of the dominants from the air which have often been described as separate plant ...
R. E. BESCHEL, P. J. WEBBER
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Gradient Models, Gradient Analysis, and Hierarchical Structure in Plant Communities
Oikos, 1997Oikos 78: 23-30. Two general models of plant community structure, the community-unit and the continuum, have dominated the thinking of American community ecologists. Hy- potheses derived from these and other models of plant community structure rarely have been tested, however.
Bruce W. Hoagland, Scott L. Collins
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Analysis Tools for Gradient Discretisations
2018Analysis tools for GDM are presented. Polytopal toolboxes enable easy proofs of the coercivity, limit-conformity and compactness of gradient discretisations. The notion of local linearly exact gradient discretisations provides ways to analyse the consistency of GDs, as well as precise estimates on the consistency error.
Jérôme Droniou +4 more
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