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Yenal Akgün Charis J. Gantes Konstantinos E. Kalochairetis Eleftheria E. Gkagka 《基于设计的结构力学与机械力学》2017,45(2):271-279
In this paper, a novel convertible stadium roof structure is introduced, which has been derived from a special geometric configuration of Watt-I linkage, a 1-DoF mechanism used in robot technologies as anthropomorphic fingers. The proposed structure can offer a wide range of different shape configurations according to the environmental conditions and spatial needs, thus offering several aesthetic and functional advantages over existing solutions. This paper serves as a feasibility investigation of this concept, mainly from geometric and structural point of view. To that affect, first kinematic analysis and geometric design of this linkage are introduced. Then, structural analyses of the proposed structure with realistic dimensions and loading conditions are performed in three different geometric configurations, in order to discuss strength and stiffness limitations. Finally, potential cover materials and actuators are briefly discussed. 相似文献
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Weakly quasi-threshold graphs form a proper subclass of the well-known class of cographs by restricting the join operation. In this paper we characterize weakly quasi-threshold graphs by a finite set of forbidden subgraphs: the class of weakly quasi-threshold graphs coincides with the class of {P 4, co-(2P 3)}-free graphs. Moreover we give the first linear-time algorithm to decide whether a given graph belongs to the class of weakly quasi-threshold graphs, improving the previously known running time. Based on the simplicity of our recognition algorithm, we can provide certificates of membership (a structure that characterizes weakly quasi-threshold graphs) or non-membership (forbidden induced subgraphs) in additional ${{\mathcal O}(n)}$ time. Furthermore we give a linear-time algorithm for finding the largest induced weakly quasi-threshold subgraph in a cograph. 相似文献
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Physics of Atomic Nuclei - The search for the associated production of a Higgs boson with a top quark–antiquark pair with the CMS detector will be presented. Candidate $$t\bar{t}H$$ events... 相似文献
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Charis D. Geddes 《Journal of fluorescence》2006,16(3):471-471
Announcement
Technical and Design Notes 相似文献6.
Proposed quantum experiments in deep space will be able to explore quantum information issues in regimes where relativistic effects are important. In this essay, we argue that a proper extension of quantum information theory into the relativistic domain requires the expression of all informational notions in terms of quantum field theoretic (QFT) concepts. This task requires a working and practicable theory of QFT measurements. We present the foundational problems in constructing such a theory, especially in relation to longstanding causality and locality issues in the foundations of QFT. Finally, we present the ongoing Quantum Temporal Probabilities program for constructing a measurement theory that (i) works, in principle, for any QFT, (ii) allows for a first- principles investigation of all relevant issues of causality and locality, and (iii) it can be directly applied to experiments of current interest. 相似文献
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A cograph completion of an arbitrary graph G is a cograph supergraph of G on the same vertex set. Such a completion is called minimal if the set of edges added to G is inclusion minimal. In this paper we present two results on minimal cograph completions. The first is a characterization that allows us to check in linear time whether a given cograph completion is minimal. The second result is a vertex incremental algorithm to compute a minimal cograph completion H of an arbitrary input graph G in O(|V(H)|+|E(H)|) time. An extended abstract of the result has been already presented at FAW 2008 [D. Lokshtanov, F. Mancini, C. Papadopoulos, Characterizing and computing minimal cograph completions, in: Proceedings of FAW’08-2nd International Frontiers of Algorithmics Workshop, in: LNCS, vol. 5059, 2008, pp. 147158. [1]]. 相似文献
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A.Charis R. Croft 《Journal of organometallic chemistry》2003,683(1):120-130
Chloride ligand substitution reactions of tert-butyl- and arylimido-titanium complexes supported by the pendant arm functionalised N-trimethylsilyl benzamidinate ligand Me3SiNC(Ph)NCH2CH2CH2NMe2 are described. Reaction of previously-described [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}Cl] (1) with PhLi afforded thermally sensitive [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}Ph] (2). The corresponding reaction of 1 with MeLi afforded [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}Me] (3) detected by 1H-NMR spectroscopy but this compound could not be isolated. Reaction of 1 with LiCH2SiMe3 gave a complex mixture, but with LiN(SiMe3)2 and LiO-2,6-C6H3Me2 the compounds [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}X] (X=N(SiMe3)2 (4) or O-2,6-C6H3Me2 (5)) were isolated. The X-ray structure of 5 was determined. Reaction of the homologous compound [Ti(NtBu){Me3SiNC(Ph)NCH2CH2NMe2}Cl] (6) (containing a 2-carbon atom chain in the pendant arm) with MeLi or PhLi were unsuccessful although the aryloxide compound [Ti(NtBu){Me3SiNC(Ph)NCH2CH2NMe2}(O-2,6-C6H3Me2)] (7) could be isolated from the reaction of 6 with LiO-2,6-C6H3Me2. Reaction of the 3-carbon pendant arm arylimido compound [Ti(N-2,6-C6H3Me2){Me3SiNC(Ph)NCH2CH2CH2NMe2}Cl] (8) with MeLi afforded thermally sensitive [Ti(N-2,6-C6H3Me2){Me3SiNC(Ph)NCH2CH2CH2NMe2}Me] (9), and although the analogous phenyl homologue was elusive, the aryloxide derivative [Ti(N-2,6-C6H3Me2){Me3SiNC(Ph)NCH2CH2CH2NMe2}(O-2,6-C6H3Me2)] (10) was successfully isolated and structurally characterised. Comparison of the X-ray structures of 5 and 10 show unexpectedly large differences between the TiNR and TiOAr bond lengths in the two compounds. 相似文献