783 research outputs found

    The Energy-Efficient Dynamic Route Planning for Electric Vehicles

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    Aiming to provide an approach for finding energy-efficient routes in dynamic and stochastic transportation networks for electric vehicles, this paper addresses the route planning problem in dynamic transportation network where the link travel times are assumed to be random variables to minimize total energy consumption and travel time. The changeable signals are introduced to establish state-space-time network to describe the realistic dynamic traffic network and also used to adjust the travel time according to the signal information (signal cycle, green time, and red time). By adjusting the travel time, the electric vehicle can achieve a nonstop driving mode during the traveling. Further, the nonstop driving mode could avoid frequent acceleration and deceleration at the signal intersections so as to reduce the energy consumption. Therefore, the dynamically adjusted travel time can save the energy and eliminate the waiting time. A multiobjective 0-1 integer programming model is formulated to find the optimal routes. Two methods are presented to transform the multiobjective optimization problem into a single objective problem. To verify the validity of the model, a specific simulation is conducted on a test network. The results indicate that the shortest travel time and the energy consumption of the planning route can be significantly reduced, demonstrating the effectiveness of the proposed approaches. Document type: Articl

    Forward study of the structural materials for the supporting system of the clic two-beam module

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    The supporting system for the CLIC Two-Beam Module plays a fundamental role for the support and alignment of the RF-components. Thus, the structural materials of the girder and V-shaped supports, along with their corresponding joining methods, need to follow a dedicated study. So far, one baseline and one so-called alternative material have been studied and the very first supporting system prototypes have been produced out of both materials, and undergo validation testing. The stiffness properties in combination with issues faced regarding the precise assembly of the V-shaped supports and the girders require an additional study. The aim of this thesis is to investigate and study potential candidate materials which present similar mechanical properties compared to the materials used for the prototype fabrications so far. The thesis is divided by the theoretical part, followed by the experimental part. In the theoretical part, the mechanical properties of selected materials are studied and compared. The factors limiting the material selection for the supporting system and their corresponding joining methods for the different materials are studied. In addition, the thesis focuses on determining an innovative testing methodology for the studied materials. Furthermore, the relevant optical inspection is foreseen to validate and to provide additional information regarding the surface quality and shape of the fractured area on the candidate materials which will be tested. The goal of the testing part is to obtain and process the experimental data through a series of mechanical and possibly radiation tests on material specimens, in order to validate and confirm or reject the potential use of the tested materials for CLIC fabrications, such as the supporting system of the Module or other. Moreover, the scientific approach of the thesis can result to a useful extension on the material mapping that takes place for the CLIC structural materials

    Preparation and solution properties of a novel cationic hydrophobically modified polyacrylamide for enhanced oil recovery

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    Financial support from National Natural Science Foundation of China (51504050, 51774062), Scientific and Technological Research Program of Chongqing Municipal Education Commission (KJ1601305) and Research Foundation of Chongqing University of Science & Technology (CK2016B07, CK2016Z20).Peer reviewedPostprin

    Unshifted Metastable He I* Mini-Broad Absorption Line System in the Narrow Line Type 1 Quasar SDSS J080248.18++551328.9

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    We report the identification of an unusual absorption line system in the quasar SDSS J080248.18++551328.9 and present a detailed study of the system, incorporating follow-up optical and NIR spectroscopy. A few tens of absorption lines are detected, including He I*, Fe II* and Ni II* that arise from metastable or excited levels, as well as resonant lines in Mg I, Mg II, Fe II, Mn II, and Ca II. All of the isolated absorption lines show the same profile of width Δv1,500\Delta v\sim 1,500km s1^{-1} centered at a common redshift as that of the quasar emission lines, such as [O II], [S II], and hydrogen Paschen and Balmer series. With narrow Balmer lines, strong optical Fe II multiplets, and weak [O III] doublets, its emission line spectrum is typical for that of a narrow-line Seyfert 1 galaxy (NLS1). We have derived reliable measurements of the gas-phase column densities of the absorbing ions/levels. Photoionization modeling indicates that the absorber has a density of nH(1.02.5)×105 cm3n_{\rm H} \sim (1.0-2.5)\times 10^5~ {\rm cm}^{-3} and a column density of NH(1.03.2)×1021cm2N_{\rm H} \sim (1.0-3.2)\times 10^{21} \sim {\rm cm}^{-2}, and is located at R100250R\sim100-250 pc from the central super-massive black hole. The location of the absorber, the symmetric profile of the absorption lines, and the coincidence of the absorption and emission line centroid jointly suggest that the absorption gas is originated from the host galaxy and is plausibly accelerated by stellar processes, such as stellar winds \zhy{and/or} supernova explosions. The implications for the detection of such a peculiar absorption line system in an NLS1 are discussed in the context of co-evolution between super-massive black hole growth and host galaxy build-up.Comment: 28 pages, 16 figures; accepted for publication in Astrophysical Journa
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