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We investigated the edge atomic structures and elastic properties of defect-free phosphorene nanoribbons (PNRs). Density functional tight binding simulations were used to optimize two main edge configurations: armchair (AC) and zi...
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We investigated the edge atomic structures and elastic properties of defect-free phosphorene nanoribbons (PNRs). Density functional tight binding simulations were used to optimize two main edge configurations: armchair (AC) and zigzag (ZZ). It was found that the energy relaxation of PNRs leads to the noticeable changes in edge atomic configurations. The effective width of the edge region, which includes all the atoms involved in the edge relaxation, was found to contain approximately three atomic rows near the edge for both AC and ZZ PNRs. We further extracted the edge stress and modulus for the ZZ and AC edges. Both the AC and ZZ edge stresses of PNRs are positive, indicating tensile stress at the edges. In addition, both the AC and ZZ edge moduli are positive. However, the edge elastic modulus and edge stress of ZZ PNRs are about three times larger than those of AC PNRs. Furthermore, we showed that the tensile edge stresses along ZZ and AC edges are able to cause distortion in freestanding phosphorene nanoribbons. Our results highlight the importance of accounting for edge stresses in the design and fabrication of PNRs.
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A gradient image describes the differences of neighboring pixels in the image. Extracting edges only depending on a gradient image will results in noised and broken edges. Here, we propose a two-stage edge extraction approach with...
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A gradient image describes the differences of neighboring pixels in the image. Extracting edges only depending on a gradient image will results in noised and broken edges. Here, we propose a two-stage edge extraction approach with contextual-filter edge detector and multiscale edge tracker to solve the problems. The edge detector detects most edges and the tracker refines the results as well as reduces the noised or blurred influence; moreover, the extracted results are nearly thinned edges which are suitable for most applications. Based on six wavelet basis functions, qualitative and quantitative comparisons with other methods show that the proposed approach extracts better edges than the other wavelet-based edge detectors and Canny detector extract.
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Quality requirements for cold-rolled products include dimensional accuracies (in particular, thickness and width), good flatness, and defect-free strip surface and edges. High expectation on thin gauge and ultra-thin gauge product...
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Quality requirements for cold-rolled products include dimensional accuracies (in particular, thickness and width), good flatness, and defect-free strip surface and edges. High expectation on thin gauge and ultra-thin gauge products has imposed increasing challenges to satisfy these quality demands. This paper discusses issues associated with edge trimming at the pickle line and their effects on the edge quality of the cold-rolled strip. Little systematic studies have been conducted on how trimmed edge quality affects the edge crack or serrated edge defect after cold rolling. It has been well accepted, however, that the cut-to-break ratio of trimmed edges is paramount to ensuring quality cold-rolled edges. This is normally controlled by adjusting the gaps and overlaps of the edge trimmer blades, with a 33:67 cut-to-break ratio generally regarded as the optimum. In this paper, we report results from our experimental studies on the mechanism of shearing the strip edge, in particular, the formation of the cut and break regions. In addition, the behaviour of these cut and break regions, and the evolution of the edge cracks, during cold rolling will be discussed. The results from this study indicate that the cut and break regions are not deformed uniformly during rolling and the edge cracks arising from the cut and break regions exhibit different features.
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摘要 :
Quality requirements for cold-rolled products include dimensional accuracies (in particular, thickness and width), good flatness, and defect-free strip surface and edges. High expectation on thin gauge and ultra-thin gauge product...
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Quality requirements for cold-rolled products include dimensional accuracies (in particular, thickness and width), good flatness, and defect-free strip surface and edges. High expectation on thin gauge and ultra-thin gauge products has imposed increasing challenges to satisfy these quality demands. This paper discusses issues associated with edge trimming at the pickle line and their effects on the edge quality of the cold-rolled strip. Little systematic studies have been conducted on how trimmed edge quality affects the edge crack or serrated edge defect after cold rolling. It has been well accepted, however, that the cut-to-break ratio of trimmed edges is paramount to ensuring quality cold-rolled edges. This is normally controlled by adjusting the gaps and overlaps of the edge trimmer blades, with a 33:67 cut-to-break ratio generally regarded as the optimum. In this paper, we report results from our experimental studies on the mechanism of shearing the strip edge, in particular, the formation of the cut and break regions. In addition, the behaviour of these cut and break regions, and the evolution of the edge cracks, during cold rolling will be discussed. The results from this study indicate that the cut and break regions are not deformed uniformly during rolling and the edge cracks arising from the cut and break regions exhibit different features.
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Edge detection referred to the course of identifying and tracing, locating sharp discontinuities in an image. The discontinuities are abrupt changes in pixel intensity value which distinguish boundaries of objects in a scene. Clas...
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Edge detection referred to the course of identifying and tracing, locating sharp discontinuities in an image. The discontinuities are abrupt changes in pixel intensity value which distinguish boundaries of objects in a scene. Classical methods of edge detection involve convolving the image object through an operator 2-Dimension filter, which is built to be subtle to large gradients in the image while returning zero values in uniform regions. This is an exceedingly large number of edge detection operators available, each intended to be very sensitive to certain types of edges. Variables involved in the selection of edge detection operators that include Gradient, Laplacian, Laplacian of Gaussian. This paper presents an analysis of edge boundary point detection to improve edge detection techniques.
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We propose a method for detecting moving objects by using edge vector and edge reliability. Regions of moving objects can be detected by utilizing a background image taken by a fixed camera. However it is difficult to detect them ...
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We propose a method for detecting moving objects by using edge vector and edge reliability. Regions of moving objects can be detected by utilizing a background image taken by a fixed camera. However it is difficult to detect them correctly in scene when brightness is changing. For this problem we propose an edge selection process and use edge detector with edge vector and edge reliability. Edge reliability is a measure of noise influences and it is invariance for brightness changing. Edge selection process can detect moving edges by using edge similarity calculated from edge vector and edge reliability, comparing a background image and an input image. Experiments show that our method can detect moving edge points stably in flickeringly scenes.
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In this paper, some types of edge irregular intuitionistic fuzzy graphssuch as neighbourly edge totally irregular intuitionistic fuzzy graphs, stronglyedge irregular intuitionistic fuzzy graphs and strongly edge totally irregular ...
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In this paper, some types of edge irregular intuitionistic fuzzy graphssuch as neighbourly edge totally irregular intuitionistic fuzzy graphs, stronglyedge irregular intuitionistic fuzzy graphs and strongly edge totally irregular intuitionistic?fuzzy graphs are introduced. A comparative study between neighbourly?edge irregular intuitionistic fuzzy graphs and neighbourly edge totally?irregular intuitionistic fuzzy graphs is done. Likewise some properties of them?are studied. Finally, we have given some interesting results a bout edge irregular?IFGs that are very useful in computer science and networks.
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If an ELM is a peeling of flux surfaces from the plasma, due to a broken separatrix, current density is lost as well as particles and energy. The fast loss of a current-carrying plasma layer modifies the plasma equilibrium, leadin...
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If an ELM is a peeling of flux surfaces from the plasma, due to a broken separatrix, current density is lost as well as particles and energy. The fast loss of a current-carrying plasma layer modifies the plasma equilibrium, leading to sudden shifts in the strike points at each ELM, towards the plasma centre. An experimental study of this conjectured model of the ELM has been made at JET, showing that in all cases of Type I ELMs studied, strike point shifts were observed. In two cases studied in detail, the estimated equilibrium changes provoked by flux surface peeling agree qualitatively with the observed strike point shifts. (c) 2004 Elsevier B.V. All rights reserved.
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A new interpretation of 3 x 3 compass feature masks such as roof edge and Frei-Chen line masks is presented in the one-dimensional (1-D) frequency domain, making use of the circularity of the weight matrix. A reduced vector repres...
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A new interpretation of 3 x 3 compass feature masks such as roof edge and Frei-Chen line masks is presented in the one-dimensional (1-D) frequency domain, making use of the circularity of the weight matrix. A reduced vector representation is also introduced in consideration of the periodicity inherent in the weight vector.
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QuestionsWhat factors control broad-scale variation in edge length and three-dimensional boundary structure for a large region extending across two biomes? What is the difference in structure between natural and anthropogenic edges?
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