Journal articles: 'Structure planaire'

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Fesquet, Jean. "Diminution des densités de courant de seuil dans le cas d’une structure planaire antiguidante de type GaSb/GalnAsSb/GaSb par adjonction d’une couche métallique." Annales des Télécommunications 43, no. 3-4 (March 1988): 112–16. http://dx.doi.org/10.1007/bf02999516.

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GUHA, PARTHA, and A. GHOSE CHOUDHURY. "ON PLANAR AND NON-PLANAR ISOCHRONOUS SYSTEMS AND POISSON STRUCTURES." International Journal of Geometric Methods in Modern Physics 07, no. 07 (November 2010): 1115–31. http://dx.doi.org/10.1142/s0219887810004750.

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We construct certain new classes of isochronous dynamical systems based on the recent constructions of Calogero and Leyvraz. We show how a Poisson structure can be ascribed to such equations in ℝ3 and indicate their connection with the Nambu structures.

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Dunlop, M. W., and T. I. Woodward. "Analysis of thick, non-planar boundaries using the discontinuity analyser." Annales Geophysicae 17, no. 8 (August 31, 1999): 984–95. http://dx.doi.org/10.1007/s00585-999-0984-6.

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Abstract. The advent of missions comprised of phased arrays of spacecraft, with separation distances ranging down to at least mesoscales, provides the scientific community with an opportunity to accurately analyse the spatial and temporal dependencies of structures in space plasmas. Exploitation of the multi-point data sets, giving vastly more information than in previous missions, thereby allows unique study of their small-scale physics. It remains an outstanding problem, however, to understand in what way comparative information across spacecraft is best built into any analysis of the combined data. Different investigations appear to demand different methods of data co-ordination. Of the various multi-spacecraft data analysis techniques developed to affect this exploitation, the discontinuity analyser has been designed to investigate the macroscopic properties (topology and motion) of boundaries, revealed by multi-spacecraft magnetometer data, where the possibility of at least mesoscale structure is considered. It has been found that the analysis of planar structures is more straightforward than the analysis of non-planar boundaries, where the effects of topology and motion become interwoven in the data, and we argue here that it becomes necessary to customise the analysis for non-planar events to the type of structure at hand. One issue central to the discontinuity analyser, for instance, is the calculation of normal vectors to the structure. In the case of planar and `thin' non-planar structures, the method of normal determination is well-defined, although subject to uncertainties arising from unwanted signatures. In the case of `thick', non-planar structures, however, the method of determination becomes particularly sensitive to the type of physical sampling that is present. It is the purpose of this article to firstly review the discontinuity analyser technique and secondly, to discuss the analysis of the normals to thick non-planar structures detected in magnetometer data. Key words. Space plasma physics (discontinuities; instruments and techniques)

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Chua, Cier Siang, Ming Lin Julius Tsai, Min Tang, Sheel Aditya, and Zhong Xiang Shen. "Microfabrication of a Planar Helix with Straight-Edge Connections Slow-Wave Structure." Advanced Materials Research 254 (May 2011): 17–20. http://dx.doi.org/10.4028/www.scientific.net/amr.254.17.

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A 100GHz planar helix with straight-edge connections slow-wave structure incorporating coplanar waveguide feed has been designed and fabricated. The proposed fabrication process can produce high-aspect-ratio planar helical structures which is essential for sheet electron beam traveling-wave tube application. The photoresists used in this process can be easily stripped after electroplating of three-dimensional structures.

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Zhumabekov, A. Zh, A. E. Sadykova, and E. V. Seliverstova. "Nitrided Silicon-Carbon Coatings Structure and Properties." Bulletin of the Karaganda University. "Physics" Series 98, no. 2 (June 30, 2020): 18–23. http://dx.doi.org/10.31489/2020ph2/18-23.

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In this paper, planar structures of various configurations based on TiO2 and graphene oxide are synthesized. Using SEM, it is shown that graphene oxide forms an insular film both on the surface and under the TiO2 layer during deposition. As well as SEM images show that TiO2 nanoparticles on the surface of graphene oxide are distributed as evenly as on the surface of FTO glass. The absorption spectra of synthesized films are a combination of the absorption curves of the original components. In this case, there is a shift of the absorption band of the planar structure nanocomposite to the longwave region. It is shown that in planar ensembles, the photoelectrochemical activity of films is higher only for the first lighting cycle. Research shows that the amount of graphene oxide affects not only the optical and photoelectrochemical properties, but also the electrical parameters. The latter, in turn, show that the resistance decreases by 1.3 times in the planar structure of graphene oxide with 30 layers. It was found that in planar structures of nanocomposite materials, the location of graphene oxide also affects the overall properties of the material. Research shows that the best indicators of photoinduced current generation are registered for the FTO/GO/TiO2 structure. Thus, a nanocomposite material in a planar structure based on TiO2 and graphene oxide depends on the architecture of the location and deposited volume of graphene oxide.

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Pietruszka, Rafal, Bartlomiej S. Witkowski, Monika Ozga, Katarzyna Gwozdz, Ewa Placzek-Popko, and Marek Godlewski. "9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber." Beilstein Journal of Nanotechnology 12 (July 21, 2021): 766–74. http://dx.doi.org/10.3762/bjnano.12.60.

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Today, silicon solar cells (amorphous films and wafer-based) are a main source of green energy. These cells and their components are produced by employing various technologies. Unfortunately, during the production process, chemicals that are harmful for the environment and for human life are used. For example, hydrofluoric acid is used to texture the top electrode to improve light harvesting. In this work, and also in recent ones, we report a way to obtain 3D textures on the top electrode by using zinc oxide nanorods. The efficiency of a textured solar cell structure is compared with the one obtained for a planar zinc oxide/silicon structure. The present results show the possibility to produce efficient solar cells on a relatively thin 50 μm thick silicon substrate. Solar cells with structured top electrodes were examined by numerous measuring techniques. Scanning electron microscopy revealed a grain-like morphology of the magnesium-doped zinc oxide film. The size of the grains is closely related to the structure of the nanorods. The external quantum efficiency of the cells was measured. The obtained solar cell shows response in a wide spectral range from ultraviolet to infrared. Current–voltage and current–voltage–temperature measurements were performed to evaluate basic photovoltaic parameters. At room temperature, the cells efficiency equals to 9.1% for textured structures and 5.4% for planar structures, respectively. The work, therefore, describes an environmentally friendly technology for PV architecture with surface textures increasing the efficiency of PV cells.

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Britton, Doyle. "Planar packing of tetrachlorodicyanobenzenes. II." Acta Crystallographica Section B Structural Science 65, no. 1 (December 20, 2008): 54–58. http://dx.doi.org/10.1107/s0108768108035234.

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Equimolar mixtures of ortho- and meta-, or ortho- and para-, or meta- and para-tetrachlorodicyanobenzene, C6Cl4(CN)2, form structures with disordered layers containing both kinds of molecules in rhombohedral or pseudo-rhombohedral cells. These structures are similar to the structure of the rhombohedral form of the meta isomer. The guiding force appears to be an intermolecular synthon, in which a nitrile group in one molecule interacts with Cl atoms in two adjacent molecules with N...Cl distances of approximately 3.1 Å.

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Lin, H. P., S. C. Chang, and C. Chu. "Modal Characteristics of Planar Multi-Story Frame Structures." Journal of Mechanics 32, no. 5 (August 19, 2016): 501–14. http://dx.doi.org/10.1017/jmech.2016.69.

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AbstractIn linear system, in-plane motions are decoupled from out-of-plane motions for planar frame structures. A theoretical method is proposed that permits the efficient calculations of modal characteristics of planar multi-story frame structures. There are 3 × m beam components for a planar m-story frame structure. By analyzing the transverse and longitudinal motions of each component simultaneously and considering the compatibility requirements across each frame joint, the undetermined variables of the entire m-story frame structure system can be reduced to six, regardless of the number of stories, and that can be determined by the application of the boundary conditions. The main feature of this method is to decrease the dimensions of the matrix involved in the finite element methods and certain other analytical methods.

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Pangkam, Nattapong, and Thitiphan Chimsook. "The Structure Activity Relationship and Cytotoxicity between Stemonal and 6-Deoxyclitoriacetal." Advanced Materials Research 699 (May 2013): 698–702. http://dx.doi.org/10.4028/www.scientific.net/amr.699.698.

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Stemonal and 6-deoxyclitoriacetal, rotenoid compounds were isolated from the dried roots of Stemona collinsae Craib. Stemonal was recrystallized with methanol. Crystal structure of stemonal displayed only the planar structures while that of 6-deoxyclitoriacetal showed both the planar and bent shape structures. Stemonal and 6-deoxyclitoriacetal were tested their cytotoxic activities against three cancer cell lines and found that only 6-deoxyclitoriacetal has been showed the cytotoxicity.

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Specchia, Stefania, Ugo A. Icardi, Corrado Spinella, Vincenzo Baglio, Claudia D'Urso, Alessandro Stassi, Vincenzo Antonucci, Antonino S. Aricò, and Giuseppe D'Arrigo. "Planar Structure μDMFCs." ECS Transactions 17, no. 1 (December 18, 2019): 485–89. http://dx.doi.org/10.1149/1.3142778.

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Yuan, Yizhe, Xiaoyong Guo, Liqun An, and Wen Xu. "Terahertz planar waveguide devices based on graphene." Modern Physics Letters B 31, no. 05 (February 20, 2017): 1750045. http://dx.doi.org/10.1142/s0217984917500452.

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We present a theoretical study on graphene-semiconductor planar structures. The frequency of the photonic modes in the structure, which can be efficiently tuned via varying the sample parameters, is within the terahertz (THz) bandwidth. Furthermore, it is found that a roughly linear dispersion relation can be obtained for photonic modes in the THz region. Hence, the proposed graphene-semiconductor planar structures can be served as THz waveguide with desirable transmission characteristics.

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Byun, Yanga, and Kyungsook Han. "An efficient algorithm for planar drawing of RNA structures with pseudoknots of any type." Journal of Bioinformatics and Computational Biology 14, no. 03 (June 2016): 1650009. http://dx.doi.org/10.1142/s0219720016500098.

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An RNA pseudoknot is a tertiary structural element in which bases of a loop pair with complementary bases are outside the loop. A drawing of RNA secondary structures is a tree, but a drawing of RNA pseudoknots is a graph that has an inner cycle within a pseudoknot and possibly outer cycles formed between the pseudoknot and other structural elements. Visualizing a large-scale RNA structure with pseudoknots as a planar drawing is challenging because a planar drawing of an RNA structure requires both pseudoknots and an entire structure enclosing the pseudoknots to be embedded into a plane without overlapping or crossing. This paper presents an efficient heuristic algorithm for visualizing a pseudoknotted RNA structure as a planar drawing. The algorithm consists of several parts for finding crossing stems and page mapping the stems, for the layout of stem-loops and pseudoknots, and for overlap detection between structural elements and resolving it. Unlike previous algorithms, our algorithm generates a planar drawing for a large RNA structure with pseudoknots of any type and provides a bracket view of the structure. It generates a compact and aesthetic structure graph for a large pseudoknotted RNA structure in O([Formula: see text]) time, where n is the number of stems of the RNA structure.

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Béguin, Alain, Gerd Rheinwald, Helen Stoeckli-Evans, and Georg Süss-Fink. "Construction de complexes tétranucléaires de ruthénium à ossature planaire par condensation de deux unités diruthénium à l'aide de ligands pontants: Synthèse et structure moléculaire de [Ru4(CO)8{μ2-P(Cy)2}4] et de [Ru4(CO)8{μ4-P(Cy)}2{μ2-P(Cy)2}2] (Cy =." Helvetica Chimica Acta 77, no. 2 (March 23, 1994): 525–32. http://dx.doi.org/10.1002/hlca.19940770213.

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Honari-Latifpour, Mostafa, and Leila Yousefi. "Topological plasmonic edge states in a planar array of metallic nanoparticles." Nanophotonics 8, no. 5 (March 14, 2019): 799–806. http://dx.doi.org/10.1515/nanoph-2018-0230.

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AbstractPhotonic topological insulators (PTIs) are electromagnetic structures with highly robust unidirectional edge states, originating from their nontrivial bulk band topology. Here, we propose a plasmonic PTI that supports highly confined one-way edge states capable of transporting deep subwavelength optical frequency plasmons through arbitrary paths without back-scattering. The structure consists of a simple planar array of coupled plasmonic nanoparticles arranged in a perturbed honeycomb lattice that exhibits nontrivial band topology. The operation frequency of the emergent edge states is shown to be independent of the lattice constant, allowing for the miniaturization of the structure. As a high-frequency PTI with a simple and planar design, this structure is compatible with well-established integrated nanofabrication technologies and may find application in planar, compact, and topologically robust integrated nanophotonic devices.

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15

Shibahara, H. "Electron microscope study of the structure of SrMnO3−x with planar defect." Journal of Materials Research 6, no. 3 (March 1991): 565–73. http://dx.doi.org/10.1557/jmr.1991.0565.

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Structures of some phases in the SrMnO3−x system accompanied by planar defect were studied using a high resolution electron microscope. A four-layer structure with a hexagonal unit cell was found to have an oxygen deficiency in some degree followed by planar defects normal to the c-axis which are classified into several types. On the basis of observed images showing an irregular stacking along the c-axis in the hexagonal unit, the distribution and the origin of the planar defect are discussed. A structure image showed the transformation of the four-layer phase into a nonstoichiometric state and a shear structure with a displacement vector of occurring between the face-sharing octahedra. Experiment by in situ observation during beam irradiation in an electron microscope indicates the process of the formation of the planar defect. A mechanism for the formation of the planar defect is proposed by which oxygen deficiency in face-sharing octahedra induces the displacement of SrO3 layers and oxygen octahedra which reduce the coordination number of Mn ions and the disruption of face-sharing octahedra.

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Tao, Qi Cheng. "Simulation for SAR Feature Image of Planar Structures." Advanced Materials Research 1042 (October 2014): 145–49. http://dx.doi.org/10.4028/www.scientific.net/amr.1042.145.

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With the progress of the SAR technology, the resolution of SAR image has enhanced constantly. The characteristics of the structure is starting to look increasingly apparent. The simulating to the structures’ characteristics of SAR image can helps people access to the target information which is contained in SAR image easily in complex cases. This paper presents a simulation based on model-cutting, combined with the technique of ray-tracing to simulate the typical SAR image characteristics of target structures of the city. For example, layover, shadow, and other major features such as secondary scattering. This method can effectively simulate typical SAR image plane of the structure, and without regard to the specific physical imaging mechanism itself, is a simple and effective manner SAR image simulation methods.

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Lu, Shaohua, Chuncheng Yang, Dong Fan, and Xiaojun Hu. "Perfect planar tetra-coordinated MC6 monolayer: superior anode material for Li-ion battery." Physical Chemistry Chemical Physics 21, no. 27 (2019): 15187–94. http://dx.doi.org/10.1039/c9cp01825e.

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Shi, Pengcheng, Qin Ye, and Lingwen Zeng. "A Novel Indoor Structure Extraction Based on Dense Point Cloud." ISPRS International Journal of Geo-Information 9, no. 11 (November 2, 2020): 660. http://dx.doi.org/10.3390/ijgi9110660.

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Herein, we propose a novel indoor structure extraction (ISE) method that can reconstruct an indoor planar structure with a feature structure map (FSM) and enable indoor robot navigation using a navigation structure map (NSM). To construct the FSM, we first propose a two-staged region growing algorithm to segment the planar feature and to obtain the original planar point cloud. Subsequently, we simplify the planar feature using quadtree segmentation based on cluster fusion. Finally, we perform simple triangulation in the interior and vertex-assignment triangulation in the boundary to accomplish feature reconstruction for the planar structure. The FSM is organized in the form of a mesh model. To construct the NSM, we first propose a novel ground extraction method based on indoor structure analysis under the Manhattan world assumption. It can accurately capture the ground plane in an indoor scene. Subsequently, we establish a passable area map (PAM) within different heights. Finally, a novel-form NSM is established using the original planar point cloud and the PAM. Experiments are performed using three public datasets and one self-collected dataset. The proposed plane segmentation approach is evaluated on two simulation datasets and achieves a recall of approximately 99%, which is 5% higher than that of the traditional plane segmentation method. Furthermore, the triangulation performance of our method compared with the traditional greedy projection triangulation show that our method performs better in terms of feature representation. The experimental results reveal that our ISE method is robust and effective for extracting indoor structures.

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Wang, Dan Dan, Qiang Cong, Rong Qiang Liu, Cong Fa Zhang, Yan Wang, and Hong Wei Guo. "Driving Characteristic Analysis of a Planar Deployable Support Truss Structure for Space Antenna." Applied Mechanics and Materials 373-375 (August 2013): 54–64. http://dx.doi.org/10.4028/www.scientific.net/amm.373-375.54.

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As the development of space structures is increasing fast, analysis on the characteristics of those deployable structures deserve to be paid enough attention to ensure a reliable deployment on orbit. For a deployable truss structure, more than one position can be chosen as the driving positions, especially when the structure has not only 1 degree of freedom (DOF), an available choice of the driving positions shows significant importance on the performance of the space deployable structure. This paper mainly deals with a planar deployable support truss structure for space antenna by means of the closed loop equations and the Kane equation to discuss the deployment characteristics by comparison of the driving torque needed over time. A full comparison of all the possible examples of deployment analysis results under different driving modes is presented. The results show the importance of the choice of driving movements and the design of parameters and also provide a useful reference to other related truss structures.

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Panchenko, Tetiana, Maria Evseeva, Anatoliy Ranskiy, Vyacheslav Baumer, and Olga Gordienko. "Synthesis and Crystal Structure of Cadmium(II) Dichloroaquasalicylidenesemicarbazone." Chemistry & Chemical Technology 10, no. 3 (September 15, 2016): 285–90. http://dx.doi.org/10.23939/chcht10.03.285.

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Cadmium(II) complex with salicyl aldehyde semicarbozone (Н2L) has been synthesized. Based on elemental analysis and IR spectroscopy its composition – [Cd∙Н2L∙H2O∙Cl2] – has been established. The complex crystal structure has been examined using XRD analysis. The coordination polyhedron of cadmium atom is a distorted octahedron, where two cis-positions are occupied by oxygen atoms of water molecule and carbamide fragment of H2L molecule, other positions are occupied by chlorine atoms. At the same time two edges of octahedron are combined with adjoined octahedrons and form endless zigzag chains of octahedrons in the structure along the crystallographic axis. H2L molecule is a planar one due to the presence of intramolecular hydrogen bond.

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Miyazaki, R., M. Yamamoto, E. Hanamoto, H. Izumi, and K. Harada. "A line-based approach for precise extraction of road and curb region from mobile mapping data." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-5 (May 28, 2014): 243–50. http://dx.doi.org/10.5194/isprsannals-ii-5-243-2014.

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Planar structure detection from point clouds is important process in many applications such as maintenance of infrastructure facility including roads and curbs because most artificial structures consists of planar surfaces. The Mobile Mapping System can obtain a large amount of points with traveling at a standard speed. However, in the case that the high-end laser scanning system is equipped, the distribution density of points is uneven. In the point-based method, this situation causes the problem to the method of calculating geometric information using neighborhood points. In this paper, we propose a line-based region growing method in order to detect planar structures with precise boundary from point clouds with uneven distribution density of points. The precise boundary of a planar structure is maintained by appropriately creating line segments from the input clouds. We adapt the definition of neighborhood and the estimation of the normal vector to the line-based region growing. The evaluation by comparing our result with manually extracted points shows that more than 98% of curb points are detected. And, about 90% of the boundary points between a road and a curb are detected with less than 0.005 meters of the distance error.

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Kamra, Veenu, and Achim Dreher. "Multilayered Transmission Lines on Quasi-planar Substrates With Anisotropic Medium." Advances in Radio Science 17 (September 19, 2019): 77–82. http://dx.doi.org/10.5194/ars-17-77-2019.

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Abstract. This paper exhibits the extension of the discrete mode matching (DMM) method to analyze conformal structures with anisotropy. It represents a simple formalism as a basis to analyze multilayered structures with quasi-planar anisotropic dielectric layers. The dyadic Green's function is then calculated using a full-wave equivalent circuit (FWEC) of the structure, where each layer is represented with the hybrid block consisting of the tangential field components. The application is demonstrated by computing propagation constants for partially filled quasi-planar waveguides and microstrip lines with isotropic, uniaxial and biaxial anisotropic dielectrics.

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IACONO, JOHN, and WOLFGANG MULZER. "A STATIC OPTIMALITY TRANSFORMATION WITH APPLICATIONS TO PLANAR POINT LOCATION." International Journal of Computational Geometry & Applications 22, no. 04 (August 2012): 327–40. http://dx.doi.org/10.1142/s0218195912600084.

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Over the last decade, there have been several data structures that, given a planar subdivision and a probability distribution over the plane, provide a way for answering point location queries that is fine-tuned for the distribution. All these methods suffer from the requirement that the query distribution must be known in advance. We present a new data structure for point location queries in planar triangulations. Our structure is asymptotically as fast as the optimal structures, but it requires no prior information about the queries. This is a 2-D analogue of the jump from Knuth's optimum binary search trees (discovered in 1971) to the splay trees of Sleator and Tarjan in 1985. While the former need to know the query distribution, the latter are statically optimal. This means that we can adapt to the query sequence and achieve the same asymptotic performance as an optimum static structure, without needing any additional information.

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Marsan, A. L., and D. Dutta. "Construction of a Surface Model and Layered Manufacturing Data From 3D Homogenization Output." Journal of Mechanical Design 118, no. 3 (September 1, 1996): 412–18. http://dx.doi.org/10.1115/1.2826901.

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A homogenization method has been recently developed to optimize the topology of a structure. This method will suggest a structural topology, but the results will be in finite element form. Most engineering applications, however, require smooth structures, whether the faces of the structures be planar or curved. Given the topology of a three-dimensional structure as suggested by the homogenization method, an algorithm is developed to interpret the structure and generate a smooth, manufacturable surface representation of the structure. Structures designed by the homogenization method can be quite complex and traditional manufacturing technique may not be well suited for constructing them. Layered manufacturing is adopted for producing such structures and it is shown how to generate the necessary data for this novel manufacturing technique from the surface model of the structure. Some steps of the algorithm require designer inputs. Examples are given which demonstrates this algorithm.

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Buist, Amanda R., Alan R. Kennedy, and Craig Manzie. "Four salt phases of theophylline." Acta Crystallographica Section C Structural Chemistry 70, no. 2 (January 25, 2014): 220–24. http://dx.doi.org/10.1107/s2053229614000825.

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The structures of two anhydrous salt phases of theophylline, namely 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium tetrafluoroborate, C7H9N4O2+·BF4−, and 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium chloride, C7H9N4O2+·Cl−, are reported together with the structures of two monohydrate salt forms, namely 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium chloride monohydrate, C7H9N4O2+·Cl−·H2O, and 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium bromide monohydrate, C7H9N4O2+·Br−·H2O. The monohydrate structures are mutually isostructural, with the cations and anions lying on crystallographic mirror planes (Z′ = 1\over 2). The main intermolecular interaction motif is a hydrogen-bonding network in the same mirror plane. The tetrafluoroborate structure is based on planar hydrogen-bonded theopylline cation dimers; the anions interact with the dimers in a pendant fashion. The anhydrous chloride structure hasZ′ = 2 and in contrast to the other species it does not form planar hydrogen-bonded constructs, instead one-dimensional chains of cations and anions propagate parallel to the crystallographiccdirection. An earlier report claiming to describe an anhydrous structure of theophylline hydrochloride is re-examined in light of these results. It is concluded that the earlier structure has been reported in the wrong space group and that it has been chemically misidentified.

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Paidar, Vaclav. "Planar Defects and Dislocations in C40 and FCC Lattices." Key Engineering Materials 592-593 (November 2013): 67–70. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.67.

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Atomic planes at three different positions ABC form the stacking along the <111> directions in the FCC lattice and similarly along the <0001> hexagonal axis in the C40 structure in transition metal silicides. However, the structures of silicides are constituted of several stacking of identical atomic planes at four different positions: AB in C11bstructures of e.g. MoSi2, ABC in C40 structures of e.g. VSi2and ABDC in C54 structures of e.g. TiSi2disilicides. The occurrence of the fourth position essentially influences the properties of defects and consequently the mechanical properties of C40 materials.

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Bagchi, Susmit. "Surjective Identifications of Convex Noetherian Separations in Topological (C, R) Space." Symmetry 13, no. 5 (May 1, 2021): 783. http://dx.doi.org/10.3390/sym13050783.

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The interplay of symmetry of algebraic structures in a space and the corresponding topological properties of the space provides interesting insights. This paper proposes the formation of a predicate evaluated P-separation of the subspace of a topological (C, R) space, where the P-separations form countable and finite number of connected components. The Noetherian P-separated subspaces within the respective components admit triangulated planar convexes. The vertices of triangulated planar convexes in the topological (C, R) space are not in the interior of the Noetherian P-separated open subspaces. However, the P-separation points are interior to the respective locally dense planar triangulated convexes. The Noetherian P-separated subspaces are surjectively identified in another topological (C, R) space maintaining the corresponding local homeomorphism. The surjective identification of two triangulated planar convexes generates a quasiloop–quasigroupoid hybrid algebraic variety. However, the prime order of the two surjectively identified triangulated convexes allows the formation of a cyclic group structure in a countable discrete set under bijection. The surjectively identified topological subspace containing the quasiloop–quasigroupoid hybrid admits linear translation operation, where the right-identity element of the quasiloop–quasigroupoid hybrid structure preserves the symmetry of distribution of other elements. Interestingly, the vertices of a triangulated planar convex form the oriented multiplicative group structures. The surjectively identified planar triangulated convexes in a locally homeomorphic subspace maintain path-connection, where the right-identity element of the quasiloop–quasigroupoid hybrid behaves as a point of separation. Surjectively identified topological subspaces admitting multiple triangulated planar convexes preserve an alternative form of topological chained intersection property.

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Westwoord, Alistair D., Robert A. Youngman, Martha R. McCartney, Alasiair N. Cormack, and Michael R. Notis. "Oxygen incorporation in aluminum nitride via extended defects: Part III. Reevaluation of the polytypoid structure in the aluminum nitride-aluminum oxide binary system." Journal of Materials Research 10, no. 10 (October 1995): 2573–85. http://dx.doi.org/10.1557/jmr.1995.2573.

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This paper extends the concepts that were developed to explain the structural rearrangement of the wurtzite AlN lattice due to incorporation of small amounts of oxygen, and to directly use them to assist in understanding the polytypoid structures. Conventional and high-resolution transmission electron microscopy, specific electron diffraction experiments, and atomistic computer simulations have been used to investigate the structural nature of the polytypoids. The experimental observations provide compelling evidence that polytypoid structures are not arrays of stacking faults, but are rather arrays of inversion domain boundaries (IDB's). A new model for the polytypoid structure is proposed with the basic repeat structural unit consisting of a planar IDB-P and a corrugated IDB. This model shares common structural elements with the model proposed by Thompson, even though in his model the polytypoids were described as consisting of stacking faults. Small additions (≃ 1000 ppm) of silicon were observed to have a dramatic effect on the polytypoid structure. First, it appears that the addition of Si causes the creation of a new variant of the planar IDB (termed IDB-P'), different from the IDB-P defect observed in the AlN-Al2O3 polytypoids; second, the addition of Si influences the structure of the corrugated IDB, such that it appears to become planar.

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Fukuda, Masahiro, Jingning Zhang, Yung-Ting Lee, and Taisuke Ozaki. "A structure map for AB2 type 2D materials using high-throughput DFT calculations." Materials Advances 2, no. 13 (2021): 4392–413. http://dx.doi.org/10.1039/d0ma00999g.

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A structure map for AB₂ type monolayers of 3844 compounds is constructed by high-throughput DFT calculations with the symmetry-unconstrained geometry optimizations starting from ferromagnetic 1T, 1H and planar structures as initial states.

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30

Li, J., and R. Chellappa. "Structure From Planar Motion." IEEE Transactions on Image Processing 15, no. 11 (November 2006): 3466–77. http://dx.doi.org/10.1109/tip.2006.881943.

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SUCHARD, EYTAN H. "SQUARE FRACTAL ALGORITHM." Fractals 13, no. 01 (March 2005): 43–55. http://dx.doi.org/10.1142/s0218348x05002763.

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Spanning a planar graph the way D. Hilbert's curve does has various image processing and industrial applications. Spanning a planar graph by two disjoint curves with fractal properties has even more scientific and industrial uses. For example, given two liquids and an active osmosis through membrane between them, we would like to both cool the liquids and to find a cost-effective structure for the osmosis to occur. Another equivalent problem is to expose two liquids to light that passes through a transparent slab as the osmosis between them occurs. Two disjoint curves can be the answer for the required structure. Differences of lengths between the curves can also be useful. A fractal structure is obvious in the lungs, where osmosis of oxygen is vital. Fractal structures are often found in organic osmotic processes in Nature. In this article, a method for spanning a planar graph by two disjoint curves will be presented.

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Yunas, Jumril, and Yeop Majlis Burhanuddin. "Microfabrication of Sandwich Micro-Transformers." Advanced Materials Research 314-316 (August 2011): 1836–40. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1836.

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A new planar micro-transformer having sandwich spiral coil structure is fabricated using MEMS micro-fabrication technique. Stack interwinding coil is designed to achieve high coupling and higher winding number at relatively small coil area. In this work, stack sandwich interwinding coil structure is fabricated by bonding the substrates of the coil at connection pads using conductive epoxy material. This method replaces the use of conventional via connections that cause the most problem of current conductance in planar structures. The inductance of fabricated coil are measured at wide range of operating frequency using cascade GSG probe. The results show that the proposed technique is an alternative way in fabricating a simple and cost effective 3-dimensional structure of stack micro-transformer.

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Sannigrahi, Mousumi, and Friedrich Grein. "On the structure of S42+ and its formation from 2S2+•Ab initio SCF and CASSCF studies." Canadian Journal of Chemistry 72, no. 2 (February 1, 1994): 298–303. http://dx.doi.org/10.1139/v94-046.

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Ab initio studies up to the MP2/6-31G* level were performed on the geometry and energy of S42+. Eleven different structures were considered. In the RHF/6-31G* method, the square structure is the most stable, followed by the trans-planar C2h structure. S42+ (square) is 105.9 kcal/mol less stable than 2S22+. Minimum energy paths were calculated for the reaction 2S2+ → S42+, both in C2v and D2h symmetry. Using RHF/6-31G*, the transition state lies about 50 kcal/mol above the energy of square planar S42+. Using CASSCF or MP2 methods this energy can be significantly lowered (to about 33 kcal/mol in MP2/6-31G*). Calculated vibrational frequencies for the square structure are also given and compared with experimental values.

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Miyazaki, Ryuji, Makoto Yamamoto, and Koichi Harada. "Line-Based Planar Structure Extraction from a Point Cloud with an Anisotropic Distribution." International Journal of Automation Technology 11, no. 4 (June 29, 2017): 657–65. http://dx.doi.org/10.20965/ijat.2017.p0657.

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We propose a line-based region growing method for extracting planar regions with precise boundaries from a point cloud with an anisotropic distribution. Planar structure extraction from point clouds is an important process in many applications, such as maintenance of infrastructure components including roads and curbstones, because most artificial structures consist of planar surfaces. A mobile mapping system (MMS) is able to obtain a large number of points while traveling at a standard speed. However, if a high-end laser scanning system is equipped, the point cloud has an anisotropic distribution. In traditional point-based methods, this causes problems when calculating geometric information using neighboring points. In the proposed method, the precise boundary of a planar structure is maintained by appropriately creating line segments from an input point cloud. Furthermore, a normal vector at a line segment is precisely estimated for the region growing process. An experiment using the point cloud from an MMS simulation indicates that the proposed method extracts planar regions accurately. Additionally, we apply the proposed method to several real point clouds and evaluate its effectiveness via visual inspection.

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FELSNER, STEFAN, and KOLJA B. KNAUER. "ULD-Lattices and Δ-Bonds." Combinatorics, Probability and Computing 18, no. 5 (September 2009): 707–24. http://dx.doi.org/10.1017/s0963548309010001.

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We provide a characterization of upper locally distributive lattices (ULD-lattices) in terms of edge colourings of their cover graphs. In many instances where a set of combinatorial objects carries the order structure of a lattice, this characterization yields a slick proof of distributivity or UL-distributivity. This is exemplified by proving a distributive lattice structure on Δ-bonds with invariant circular flow-difference. This instance generalizes several previously studied lattice structures, in particular,c-orientations (Propp), α-orientations of planar graphs (Felsner, resp. de Mendez) and planar flows (Khuller, Naor and Klein). The characterization also applies to other instances,e.g., to chip-firing games.

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Zhang, Xiao-Feng, Volk R. Todt, and Dean J. Miller. "From meandering to straight grain boundaries: Improving the structures of artificially induced grain boundaries in superconducting YBa2Cu3Oy bicrystals." Journal of Materials Research 12, no. 11 (November 1997): 3029–35. http://dx.doi.org/10.1557/jmr.1997.0396.

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This paper presents several key aspects of our approach to preparing artificially induced [001] tilt grain boundaries (GB's) with uniform, well-defined structures in YBa2Cu3Oy (YBCO) superconductors. GB structures formed in thin film and bulk bicrystals, respectively, will be compared. In YBCO thin film bicrystals, meandering rather than planar GB's are formed. Using a low film deposition rate has been demonstrated to reduce the magnitude of meander significantly, but complete elimination of the meander has not yet been accomplished. Thus, we have developed a dual-seeded-melt-texture process to produce uniform, planar GB's with controllable misorientation angles in YBCO bulk bicrystals. Transmission electron microscopy (TEM) studies reveal a remarkably planar and simple configuration on different length scales. Such a simple structure allows for an insightful interpretation of transport behavior across individual GB's.

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Fan, Quncheng. "A new method of calculating planar density: the position-duplication-number method." Journal of Applied Crystallography 49, no. 5 (August 10, 2016): 1454–58. http://dx.doi.org/10.1107/s1600576716010827.

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The traditional method of calculating planar density requires an auxiliary sectional view showing the arrangement of atoms on the plane, this being very difficult for those planes with higher indices. In the present paper, a new position-duplication-number method is developed to calculate the planar density of all Bravais lattices and all crystal structure types using the formula ρ(hkl) (m/q) = N (hkl) (m/q) d′(hkl)/V cell. The new method is illustrated for calculating planar densities of the (110) and (579) planes of the β-cristobalite SiO2 structure, with additional examples in hexagonal close-packed, face-centred cubic and body-centred cubic systems. These examples show the advantages of the new method: it does not require any auxiliary sectional view, and it is suitable for all crystal structures and all plane indices.

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Sripothongnak, Saovalak, Natalie V. Barone, Anıl Çetin, Ruoqiu Wu, William S. Durfee, and Christopher J. Ziegler. "The structures of free-base carbahemiporphyrazines." Journal of Porphyrins and Phthalocyanines 14, no. 02 (February 2010): 170–77. http://dx.doi.org/10.1142/s1088424610001878.

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In this report we present an X-ray crystallographic study of two N -deficient hemiporphyrazines: dicarbahemiporphyrazine (1) and benziphthalocyanine (2). Both compounds can be isolated in multiple crystal forms, and five different solvated forms of macrocycle 1 are presented. Four of the five are non-planar, showing the high degree of flexibility and capacity for hydrogen bonding from solvent to N-H groups in the macrocycle. The remaining structure of 1 is a planar dicationic species that represents a tautomeric form of the macrocycle often seen in metal binding. Four structures of macrocycle 2 are also presented in this report. The structure of 2 is also planar due to the tautomerism of the internal protons, and structural elucidation of this macrocycle reveals the presence of three ionizable protons rather than the expected single proton postulated by Elvidge and Golden.

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Navaei, Neosha, Ali Roshanghias, Martin Lenzhofer, and Michael Ortner. "Analysis of Single- and Double Core Planar Fluxgate Structures." Proceedings 2, no. 13 (December 10, 2018): 831. http://dx.doi.org/10.3390/proceedings2130831.

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The planar fluxgate is an emerging technology feasible for system integration contrary to it’s bulky 3D counterpart. Recently, a novel structure based on an asymmetric double core layout for improved sensitivity and energy efficiency was proposed. The aim of this paper is, for the first time, to conduct a direct experimental comparison between single- and asymmetric double-core structures. The results confirm the original conjecture and show that asymmetric double core structures can easily boost the sensitivity by a factor of two for similar power supply.

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Wu, Ke, Houfei Fang, and Bingen Yang. "Modeling, Analyses, and Optimization of Planar Active Frame Structures Composed of Piezoelectric Beams." International Journal of Structural Stability and Dynamics 19, no. 12 (December 2019): 1950146. http://dx.doi.org/10.1142/s0219455419501463.

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Frame structures are widely used in engineering applications, especially in space structures. For special use such as shape and vibration control of such structures, piezoelectric patches are usually placed on the beam surfaces to form active frame structures. To perform shape control or vibration control tasks, modeling methods for the formed active frame structures need to be studied. This paper develops a new distributed model of an active frame structure composed of multilayer piezoelectric beam components. First, the governing equations of a beam, bonded with piezoelectric patches, are developed via the generalized Hamilton principle, by considering the transverse shear strain. Then, the analytical solutions of the governing equations and the generalized element stiffness matrix are derived through the distributed transfer function formulation. Finally, the analytical solution of the entire system is obtained by the technique for assembling element stiffness matrix. In numerical simulations, buckling and vibration of an active frame structure are both studied. In addition, a novel Improved Ant Lion algorithm is proposed for optimal design of the frame structures. The optimization examples confirm that the proposed algorithm is more efficient than other existing popular algorithms such as Genetic Algorithm (GA) and Ant Lion Optimization (ALO) algorithm.

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Järvi, Jari, Patrick Rinke, and Milica Todorović. "Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization." Beilstein Journal of Nanotechnology 11 (October 19, 2020): 1577–89. http://dx.doi.org/10.3762/bjnano.11.140.

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Identifying the atomic structure of organic–inorganic interfaces is challenging with current research tools. Interpreting the structure of complex molecular adsorbates from microscopy images can be difficult, and using atomistic simulations to find the most stable structures is limited to partial exploration of the potential energy surface due to the high-dimensional phase space. In this study, we present the recently developed Bayesian Optimization Structure Search (BOSS) method as an efficient solution for identifying the structure of non-planar adsorbates. We apply BOSS with density-functional theory simulations to detect the stable adsorbate structures of (1S)-camphor on the Cu(111) surface. We identify the optimal structure among eight unique types of stable adsorbates, in which camphor chemisorbs via oxygen (global minimum) or physisorbs via hydrocarbons to the Cu(111) surface. This study demonstrates that new cross-disciplinary tools, such as BOSS, facilitate the description of complex surface structures and their properties, and ultimately allow us to tune the functionality of advanced materials.

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Prakash, G. K. Surya, and Golam Rasul. "Cyclobutane dication, (CH2)4 2+: a model for a two-electron four-center (2e-4c) Woodward–Hoffmann frozen transition state." Beilstein Journal of Organic Chemistry 15 (July 3, 2019): 1475–79. http://dx.doi.org/10.3762/bjoc.15.148.

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The structures of the elusive cyclobutane dication, (CH2)4 2+, were investigated at the MP2/cc-pVTZ and CCSD(T)/cc-pVTZ levels. Calculations show that the two-electron four-center (2e-4c) bonded structure 1 involving four carbon atoms is a minimum. The structure contains formally two tetracoordinate and two pentacoordinate carbons. The non-classical σ-delocalized structure can be considered as a prototype for a 2e-4c Woodward–Hoffmann frozen transition state. The planar rectangular shaped structure 2 with a 2e-4c bond was found not to be a minimum.

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Fetisov, Leonid, Dmitri Chashin, Dmitri Saveliev, Daria Plekhanova, Ludmila Makarova, and Alexandr Stognii. "Magnetoelectric effect in ferromagnetic-semiconductor layered composite structures." EPJ Web of Conferences 185 (2018): 07005. http://dx.doi.org/10.1051/epjconf/201818507005.

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The results of magnetoelectric effect experimental studies in two different structures based on piezoelectric semiconductor gallium arsenide are presented. The monolithic structure consisted of a gallium arsenide substrate with deposited nickel layer (GaAs-Ni), and the composite structure contained a semiconductor substrate with an amorphous magnetic alloy (GaAs-Metglas) ribbon glued on one side. A quality factor Q ≈ 23500 and magnetoelectric coefficient of 316 V/Oe.cm were achieved at the frequency of planar acoustic oscillations for GaAs-Ni structure at room temperature.

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SANYAL, BIPLAB, and ABHIJIT MOOKERJEE. "STUDY OF THE ELECTRONIC AND STRUCTURAL PROPERTIES OF ZnO CLUSTERS." International Journal of Modern Physics B 24, no. 17 (July 10, 2010): 3297–309. http://dx.doi.org/10.1142/s0217979210052209.

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We present a systematic first-principle study of the structures, energetics and electronic structure of (ZnO) n clusters in the size range 1 ≤ n≤ 12. We show that the planar ring structures are stable for n < 8, while spheroidal structures made out of rings of (ZnO) 3 and (ZnO) 2 are stable for n ≥ 8. We examine the binding energies and HOMO–LUMO gaps of the clusters and try to understand our results from simple physical ideas.

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45

Fangmann, Pia, Marc Schmidtmann, and Rüdiger Beckhaus. "Crystal structures of 2,3,8,9,14,15-hexamethyl-5,6,11,12,17,18-hexaazatrinaphthylene and 2,3,8,9,14,15-hexaphenyl-5,6,11,12,17,18-hexazatrinaphthylene dichloromethane disolvate." Acta Crystallographica Section E Crystallographic Communications 74, no. 2 (January 16, 2018): 167–71. http://dx.doi.org/10.1107/s2056989018000725.

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The crystal structures of two substituted HATN (hexaazatrinaphthylene) derivatives, namely 2,3,8,9,14,15-hexamethyl- and 2,3,8,9,14,15-hexaphenyl-5,6,11,12,17,18- hexazatrinaphthylene (HATNMe6 and HATNPh6), are reported. Whereas the structure of the methyl-substituted derivative (HATNMe6) contains no solvent molecules (C30H24N6), the hexaphenyl-substituted structure (HATNPh6) contains two molecules of dichloromethane (C60H36N6·2CH2Cl2). This class of planar bridging ligands is known for its electron-deficient systems and its ability to form π–π stacking interactions. Indeed, in both crystal structures strong π–π stacking interactions are observed, but with different packing features. The dichloromethane molecules in the crystal structure of HATNPh6 are situated in the voids and are involved in C—H...N contacts to the nitrogen atoms of the pyrazine units.

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46

Hoch, Constantin. "The New Oxometallates Cs4[FeO3], Cs4[ZnO3] and Cs3[BO3] with Trigonal-planar Anions – Decomposition Products of Alkali Metal Suboxometallates." Zeitschrift für Naturforschung B 66, no. 12 (December 1, 2011): 1248–54. http://dx.doi.org/10.1515/znb-2011-1209.

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Three new cesium oxometallates with trigonal-planar [MO3]n− anions (M = Zn, Fe, B) were observed as products of reactions aimed at the formation of alkali metal suboxometallates A9MO4 (A = Rb, Cs; M = Al, Ga, In, Fe, Sc), or as decomposition products thereof. Cs4[FeO3], Cs4[ZnO3] and Cs3[BO3] crystallize with new structure types (Cs4[FeO3]: triclinic, space group P1̄, a = 7.0652(1), b = 7.125(1), c = 9.939(2) Å, α = 80.74(2), β = 71.32(2), γ = 64.04(2)°, Z = 2, Cs4[FeO3]: monoclinic, space group P21/c, a = 7.146(4), b = 18.572(1), c = 7.050(4) Å, β = 115.47(4)◦, Z = 4, Cs3[BO3]: orthorhombic, space group Pnma, a = 10.967(1), b = 10.967(1), c = 10.353(1) Å). In all structures the trigonal-planar anions have no or low point symmetry, but deviate only marginally from ideal 6̄m2 symmetry. The new crystal structures can be derived from simple and highly symmetrical packings of spheres or from known binary structure types.

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Butler, Ian S., and Denis F. R. Gilson. "A theoretical investigation of the products in the Frankland reaction of dimethylzinc compounds with nitric oxide." Canadian Journal of Chemistry 92, no. 10 (October 2014): 948–50. http://dx.doi.org/10.1139/cjc-2014-0049.

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The structures of two products of the Frankland reaction of dimethylzinc with nitric oxide, CH3Zn[O·N(NO)CH3] and Zn[O·N(NO)CH3]2, have been calculated using the Gaussian 03 revision B.02 programs. The more stable form of the 2:1 compound has a closed structure (II) with an energy difference of 90.7 kJ mol−1 from the open structure (I) and a barrier to conversion of 94.9 kJ mol−1. The structure of the 4:1 compound is a spiroform (III) 21.8 kJ mol−1 more stable than the planar structure, with no barrier to conversion. Some of the calculated vibrational data for structures II and III are also reported and compared with those available in the literature from previous experimental infrared and Raman measurements.

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Brouant, Pierre, Jacques Barbe, Pilar Goya, and Carmen Ochoa. "Étude structurale de l'amino-5 dibenzyl-4,4 one-3 2H-thiadiazine-1,2,6 dioxyde-1,1." Canadian Journal of Chemistry 66, no. 10 (October 1, 1988): 2477–82. http://dx.doi.org/10.1139/v88-389.

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5-Amino-4,4-dibenzyl-3-one-2H-1,2,6-thiadiazine-1,1-dioxide was structurally characterized in the solid state by X-ray diffraction. The structure shows that the title compound exists in the solid in a sheet-packed form and as the amino tautomer. The unconjugated heterocyclic ring, which in the structures of related compounds is usually folded, is planar in the present structure. 1H nuclear magnetic resonance and dipole moment data indicate that the title compound has the same structure in the solid state and in solution.

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Yoo, Seong-yeol, Young-Woo Park, and Myounggyu Noh. "Topology Selection and Parametric Design of Electromagnetic Vibration Energy Harvesters by Combining FEA-in-the-Loop and Analytical Approaches." Energies 13, no. 3 (February 2, 2020): 627. http://dx.doi.org/10.3390/en13030627.

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Electromagnetic energy harvesters have been used to capture low-frequency vibration energy of large machines such as diesel generators. The structure of an electromagnetic energy harvester is either planar or tubular. Past research efforts focus on optimally designing each structure separately. An objective comparison between the two structures is necessary in order to decide which structure is advantageous. When comparing the structures, the design variations such as magnetization patterns and the use of yokes must also be considered. In this study, extensive comparisons are made covering all possible topologies of an electromagnetic energy harvester. A bench mark harvester is defined and the parameters that produce maximum output power are identified for each topology. It is found that the tubular harvesters generally produce larger output power than the planar counterparts. The largest output power is generated by the tubular harvester with a Halbach magnetization pattern (94.7 mW). The second best is the tubular harvester with axial magnetization pattern (79.1 mW) when moving yokes are inserted between permanent magnets for flux concentration. When cost is of primary concern, the tubular harvester with axial pattern may become a best option.

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Filsø, Mette Ø., Iman Chaaban, Amer Al Shehabi, Jørgen Skibsted, and Nina Lock. "The structure-directing amine changes everything: structures and optical properties of two-dimensional thiostannates." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 73, no. 5 (September 26, 2017): 931–40. http://dx.doi.org/10.1107/s2052520617010630.

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Two different two-dimensional thiostannates (SnS) were synthesized using tris(2-aminoethyl)amine (tren) or 1-(2-aminoethyl)piperidine (1AEP) as structure-directing agents. Both structures consist of negatively charged thiostannate layers with charge stabilizing cations sandwiched in-between. The fundamental building units are Sn3S4broken-cube clusters connected by double sulfur bridges to form polymeric (Sn3S72−)nhoneycomb hexagonal layers. The compounds are members of theR-SnS-1 family of structures, whereRindicates the type of cation. Despite consisting of identical structural units, the band gaps of the two semiconducting compounds were found to differ substantially at 2.96 eV (violet–blue light) and 3.21 eV (UV light) for tren–SnS-1 and 1AEP–SnS-1, respectively. Aiming to explain the observed differences in optical properties, the structures of the two thiostannates were investigated in detail based on combined X-ray diffraction, solid-state13C and119Sn MAS NMR spectroscopy and scanning electron microscopy studies. The compound tren–SnS-1 has a hexagonal structure consisting of planar SnS layers with regular hexagonal pores and disordered cations, whereas 1AEP–SnS-1 has an orthorhombic unit cell with ordered cations, distorted hexagonal pores and non-planar SnS layers. In the formation of 1AEP–SnS-1, an intramolecular reaction of the structure-directing piperidine takes place to form anN-heterobicyclic cation throughin situC—H activation. Hirshfeld surface analysis was used to investigate the interaction between the SnS layers and cations in 1AEP–SnS-1 and revealed that the most nucleophilic part of the SnS sheets is one of the two crystallographically distinct double sulfur bridges.

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Journal articles on the topic 'Structure planaire'

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