1. |
- Fu, Le, et al.
(författare)
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Structural integrity and damage of glass-ceramics after He ion irradiation : Insights from ZrO2-SiO2 nanocrystalline glass-ceramics
- 2023
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Ingår i: Journal of the European Ceramic Society. - : Elsevier. - 0955-2219 .- 1873-619X. ; 43:6, s. 2624-2633
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Tidskriftsartikel (refereegranskat)abstract
- Developing new radiation-resistant materials and understanding the structural damages caused by radiation are persistent goals of material scientists. Here, we report on the structural integrity and damage to ZrO2-SiO2 nanocrystalline glass-ceramics after radiation with 1.4 MeV He ions at three different fluences: 1.0 x 1016 ions/ cm2 (low), 5.0 x 1016 ions/cm2 (moderate), and 1.0 x 1017 ions/cm2 (high) at 500 degrees C. Grazing incident X-ray diffraction shows the tetragonal-ZrO2 to monoclinic-ZrO2 phase transformation induced by microstrain from the irradiation. The addition of yttrium indicated tetragonal-ZrO2 stabilization effect during irradiation. The irra-diated glass-ceramics show a Raman signal-enhancement effect probably related to the electronic structure changes of the amorphous SiO2 component in the glass-ceramics. The formation of microcracks and lattice de-fects within ZrO2 nanocrystallites is the main structural damage caused by irradiation. There was no observable amorphization of ZrO2 nanocrystallites due to irradiation. No obvious He bubbles were detected, either. The formation of microcracks results in a decrease of in the nanohardness of the glass-ceramics. The results provide fundamental experimental data to understand the structural integrity and damage caused by radiation, which could be useful to design radiation-resistant nanocrystalline glass-ceramics for extremely radioactive environments.
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2. |
- Jiangping, Hu, et al.
(författare)
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Cooperative shift estimation of target trajectory using clustered sensors
- 2014
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Ingår i: Journal of Systems Science and Complexity. - : Springer Science and Business Media LLC. - 1009-6124 .- 1559-7067. ; 27:3, s. 413-429
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a mathematical model for target tracking using nonlinear scalar range sensors is formulated first. A time-shift sensor scheduling strategy is addressed on the basis of a k-barrier coverage protocol and all the sensors are divided into two classes of clusters, active cluster, and submissive cluster, for energy-saving. Then two types of time-shift nonlinear filters are proposed for both active and submissive clusters to estimate the trajectory of the moving target with disturbed dynamics. The stochastic stability of the two filters is analyzed. Finally, some numerical simulations are given to demonstrate the effectiveness of the new filters with a comparison of EKF.
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3. |
- Lin, Runzi, et al.
(författare)
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Optimal scheduling management of the parking lot and decentralized charging of electric vehicles based on Mean Field Game
- 2022
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 328
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Tidskriftsartikel (refereegranskat)abstract
- As an intermediary for the interaction between the grid and electric vehicles (EVs), the parking lot aggregator not only facilitates the exchange of electricity between EVs and the grid, but also brings benefits to all participants. This paper proposes a linear quadratic (LQ) Mean Field Game (MFG) theory with a major player to optimal scheduling management of the parking lot and formulate optimal decentralized charging control strategies for a large number of EVs, to achieve the minimization of EVs charging cost while maximizing the profit of the parking lot, but these two problems are a set of coupled control problems. In addition to modeling the interaction between the parking lot and the EVs as a finite-time dynamic game problem, the Nash Certainty Equivalence (NCE) of related optimization problems is also proposed, and the corresponding solution algorithm is designed. The control effects of the proposed dynamic game problem on the charging cycle, as well as the effects of parameters change and electricity price fluctuations on charging control are illustrated through numerical simulations.
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4. |
- Shen, Tielong, et al.
(författare)
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Microstructure and tensile properties of tungsten at elevated temperatures
- 2016
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115. ; 468, s. 348-354
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Tidskriftsartikel (refereegranskat)abstract
- In order to support the development of the 5 MW spallation target for the European Spallation Source, the effect of fabrication process on microstructure, ductile-to-brittle transition temperature (DBTT), tensile and fracture behaviour of powder-metallurgy pure tungsten materials has been investigated. A hot-rolled (HR) tungsten piece of 12 mm thickness and a hot-forged (HF) piece of about 80 mm thickness were used to simulate the thin and thick blocks in the target. The two tungsten pieces were characterized with metallography analysis, hardness measurement and tensile testing. The HR piece exhibits an anisotropic grain structure with an average size of about 330 x 140 x 40 mu m in rolling, long transverse and short transverse (thickness) directions. The HF piece possesses a bimodal grain structure with about 310 x 170 x 70 mu m grain size in deformed part and about 25 mu m sized grains remained from sintering process. Hardness (HV0.2) of the HR piece is slightly greater than that of the HF one. The ductility of the HR tungsten specimens is greater than that of the HF tungsten. For the HF tungsten piece, specimens with small grains in gauge section manifest lower ductility but higher strength. The DBTT evaluated from the tensile results is 250-300 degrees C for the HR tungsten and about 350 degrees C for the HF tungsten. (c) 2015 Elsevier B.V. All rights reserved.
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6. |
- Shen, Tielong, et al.
(författare)
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Special issue on benchmark problems in automotive system control
- 2019
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Ingår i: Control Theory and Technology. - : South China University of Technology and Academy of Mathematics and Systems Science, CAS via Springer. - 2095-6983 .- 2198-0942. ; 17:2, s. 119-120
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Tidskriftsartikel (refereegranskat)abstract
- We hope this special issue will provide new inspiring to the community of control theory, especially for the youngerresearchers and students. We wish to thank Yiguang Hong, Editor of the journal of Control Theory and Technology,for his timely organization of this special issue.
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7. |
- Thomasson, Andreas, et al.
(författare)
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Experimental Validation of a Likelihood-Based Stochastic Knock Controller
- 2016
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Ingår i: IEEE Transactions on Control Systems Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1063-6536 .- 1558-0865. ; 24:4, s. 1407-1418
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Tidskriftsartikel (refereegranskat)abstract
- New likelihood-based stochastic knock controllers have the potential to deliver a significantly improved regulatory response relative to conventional strategies, while also maintaining a rapid transient response, but evaluation studies to date have been performed only in simulation. In this paper, an experimental validation of the new strategy is presented. To demonstrate the robustness of the method, the algorithm is implemented on two different engine platforms, using two different knock intensity metrics, and evaluated under different operating conditions. One of these platforms is a five-cylinder variable compression ratio engine, enabling the controller to be tested under different compression ratios, as well as different speed and load conditions. The regulatory and transient performance of the likelihood-based controller is assessed in a back-to-back comparison with a conventional knock controller and it is shown that the new controller is able to operate closer to the knock limit with less variation in control action without increasing the risk of engine damage.
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8. |
- Xu, Fuguo, et al.
(författare)
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Real-time energy optimization of HEVs under-connected environment: a benchmark problem and receding horizon-based solution
- 2022
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Ingår i: CONTROL THEORY AND TECHNOLOGY. - : SPRINGERNATURE. - 2095-6983 .- 2198-0942. ; 20, s. 145-160
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we propose a benchmark problem for the challengers aiming to energy efficiency control of hybrid electric vehicles (HEVs) on a road with slope. Moreover, it is assumed that the targeted HEVs are in the connected environment with the obtainment of real-time information of vehicle-to-everything (V2X), including geographic information, vehicle-to-infrastructure (V2I) information and vehicle-to-vehicle (V2V) information. The provided simulator consists of an industrial-level HEV model and a traffic scenario database obtained through a commercial traffic simulator, where the running route is generated based on real-world data with slope and intersection position. The benchmark problem to be solved is the HEVs powertrain control using traffic information to fulfill fuel economy improvement while satisfying the constraints of driving safety and travel time. To show the HEV powertrain characteristics, a case study is given with the speed planning and energy management strategy.
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