| 1. |
- Li, Yuan, et al.
(author)
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Comparative Study of the Influence of Open Circuit Voltage Tests on State of Charge Online Estimation for Lithium-Ion Batteries
- 2020
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In: IEEE Access. - : IEEE. - 2169-3536. ; 8, s. 17535-17547
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Journal article (peer-reviewed)abstract
- The accurate state of charge (SoC) online estimation is a significant indicator that relates to driving ranges of electric vehicles (EV). The relationship between open circuit voltage (OCV) and SoC plays an important role in SoC estimation for lithium-ion batteries. To compare with the traditional incremental OCV (IO) test and the low current OCV (LO) test, a novel OCV test which combines IO test with LO test (CIL) is proposed in this paper. Based on the reliable parameters online identification of the dual polarization (DP) battery model, two SoC estimation algorithms are compared on the accuracy, robustness and convergence speed for the entire SoC region. Meanwhile, the comparative study of the three OCV-SoC relationships fits by the corresponding OCV tests is discussed in terms of the SoC online estimation under various temperatures. The results show that the adaptive extended Kalman filter (AEKF) algorithm can better improve the accuracy and robustness of SoC estimation than that of the extended Kalman filter (EKF) algorithm. Most importantly, the OCV-SoC relationship obtains from the CIL OCV test method is applied to the AEKF algorithm, which has higher accuracy and better statistical indices of SoC estimation, especially suitable for the low temperature.
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| 2. |
- Li, Yuan, et al.
(author)
-
Investigation on liquid cold plate thermal management system with heat pipes for LiFePO4 battery pack in electric vehicles
- 2021
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In: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311 .- 1873-5606. ; 185
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Journal article (peer-reviewed)abstract
- An appropriate battery thermal management system is essential for electric vehicles to keep an optimal working temperature range with minimal temperature difference, and meanwhile to ensure the battery is more efficient and safe. In this paper, the liquid cold plate thermal management system with heat pipes is proposed to investigate the thermal characteristic of LiFePO4 battery pack during various discharge rate operations. A three-dimensional numerical model based on standard k-epsilon turbulent model is developed to realize the visible analysis of fluid flow and heat transfer for the proposed thermal management system. The 50 Ah battery module is used in the experiment to validate the cooling effects of proposed thermal management system relied on heat pipes, and its performance is compared with liquid cold plate without heat pipes. Furthermore, the cooling performance of the cold plate with heat pipes could be further improved through the orthogonal experiment design, the maximum temperature of battery cell and temperature difference of battery module could be dropped by 6.95% and 11.08%, as compared with the original design. What's more, the channel height of cold plate with heat pipes has the greatest effect on the maximum temperature of battery cells and temperature difference of battery modules.
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| 3. |
- Qi, Yungeng, et al.
(author)
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Nanocellulose : a review on preparation routes and applications in functional materials
- 2023
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In: Cellulose. - 0969-0239 .- 1572-882X. ; 30:7, s. 4115-4147
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Research review (peer-reviewed)abstract
- Nanocellulose has a wide range of applications in the field of functional materials, and it has piqued the interest of researchers for some time. This is because nanocellulose inherits the advantages of environmental friendliness and easy availability of plant cell walls in nature, as well as the unique morphology of nanostructures. This review presents four types of nanocellulose including cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), regenerated nanocellulose (RNC) and bacterial cellulose (BC), introduces the different preparation routes and their mechanisms, analyzes the advantages and drawbacks between these approaches, and summarizes the potential applications in the field of functional materials such as reinforced composite materials, biomedical materials, soft templates, and optical materials. Finally, future development directions are proposed including further enrichment of nanocellulose raw materials, improvement of preparation methods to adapt to more diversified raw materials, and classification of products according to their morphology and properties to improve the use efficiency.
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| 4. |
- Shi, Furong, et al.
(author)
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A Nitroxide Radical Conjugated Polymer as an Additive to Reduce Nonradiative Energy Loss in Organic Solar Cells
- 2023
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In: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 35:23
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Journal article (peer-reviewed)abstract
- Nonfullerene-acceptor-based organic solar cells (NFA-OSCs) are now set off to the 20% power conversion efficiency milestone. To achieve this, minimizing all loss channels, including nonradiative photovoltage losses, seems a necessity. Nonradiative recombination, to a great extent, is known to be an inherent material property due to vibrationally induced decay of charge-transfer (CT) states or their back electron transfer to the triplet excitons. Herein, it is shown that the use of a new conjugated nitroxide radical polymer with 2,2,6,6-tetramethyl piperidine-1-oxyl side groups (GDTA) as an additive results in an improvement of the photovoltaic performance of NFA-OSCs based on different active layer materials. Upon the addition of GDTA, the open-circuit voltage (VOC), fill factor (FF), and short-circuit current density (JSC) improve simultaneously. This approach is applied to several material systems including state-of-the-art donor/acceptor pairs showing improvement from 15.8% to 17.6% (in the case of PM6:Y6) and from 17.5% to 18.3% (for PM6:BTP-eC9). Then, the possible reasons behind the observed improvements are discussed. The results point toward the suppression of the CT state to triplet excitons loss channel. This work presents a facile, promising, and generic approach to further improve the performance of NFA-OSCs.
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| 5. |
- Middelburg, Luke M., et al.
(author)
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Impedance Spectroscopy for Enhanced Data Collection of Conductometric Soot Sensors
- 2020
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In: IEEE International Symposium on Industrial Electronics. ; 2020-June, s. 1099-1103
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Conference paper (peer-reviewed)abstract
- Impedance spectroscopy in the frequency range 100 Hz to 10 kHz has been applied to the Inter-Digitated Electrode (IDE) structure that is conventionally operated as a resistive sensor for the measurement of Particulate Matter (PM). The measurement of both the in-phase (resistive) and out-of-phase (capacitive) components of the impedance over this frequency range provides more data on PM as compared to DC resistance measurement only. Experimental validation confirms a more gradual change in capacitance with soot buildup as compared to the sudden reduction of resistance with dendrite formation. The effect of an additional vertical electric field for an increased capacitive sensitivity due to stimulated soot buildup has been experimentally investigated using the electrically conductive flow housing of the IDE structure as an additional suspended electrode.
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| 6. |
- Jia, Qi, et al.
(author)
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Effects of Fine Content, Binder Type and Porosity on Mechanical Properties of Cemented Paste Backfill with Co-Deposition of Tailings Sand and Smelter Slag
- 2016
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In: Electronic Journal of Geotechnical Engineering. - : Mete Öner. - 1089-3032. ; 21:20, s. 6971-6988
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Journal article (peer-reviewed)abstract
- Mine backfilling is a process where the underground voids resulted from mining are filled with waste materials. The potential of co-depositing iron sand produced from smelting process with tailings sand was investigated in the present study. Different amounts of iron sand were mixed with the tailings sand to prepare cemented paste backfill (CPB) samples. Two types of binders were used. Uniaxial compression tests were performed for the CPB samples after 28 days of curing. The porosities of the samplers after curing were calculated to correlate the porosity with the uniaxial compression strength, UCS. Results from uniaxial compression tests showed that the amount of iron sand and the type of the binder influences the UCS, as well as content values of fines and porosity. These results demonstrated the possibility for a part of Fe-sand to be deposited together with the tailings sand to increase UCS values for the CPB samples, which will be beneficial for both mining operation and environmental protection.
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| 7. |
- Li, Zexian, et al.
(author)
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5GCAR project D3.1 Intermediate 5G V2X Radio
- 2018
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Reports (other academic/artistic)abstract
- The 5GCAR project aims to contribute to 5G network design, and specifically to design V2X technology components for V2X use case classes identified in the project. The requirements on reliability, latency, data rates, spectral and energy efficiency cannot be fully supported by today’s wireless networks and V2X solutions and call for novel and innovative approaches, including the design of a new radio interface.
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| 8. |
- Middelburg, Luke M., et al.
(author)
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Maintaining transparency of a heated MEMs membrane for enabling long-term optical measurements on soot-containing exhaust gas
- 2020
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In: Sensors. - : MDPI AG. - 1424-8220. ; 20:1
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Journal article (peer-reviewed)abstract
- Ensuring optical transparency over a wide spectral range of a window with a view into the tailpipe of the combustion engine, while it is exposed to the harsh environment of sootcontaining exhaust gas, is an essential pre-requisite for introducing optical techniques for long-term monitoring of automotive emissions. Therefore, a regenerable window composed of an optically transparent polysilicon-carbide membrane with a diameter ranging from 100 µm up to 2000 µm has been fabricated in microelectromechanical systems (MEMS) technology. In the first operating mode, window transparency is periodically restored by pulsed heating of the membrane using an integrated resistor for heating to temperatures that result in oxidation of deposited soot (600–700 °C). In the second mode, the membrane is kept transparent by repelling soot particles using thermophoresis. The same integrated resistor is used to yield a temperature gradient by continuous moderate-temperature heating. Realized devices have been subjected to laboratory soot exposure experiments. Membrane temperatures exceeding 500 °C have been achieved without damage to the membrane. Moreover, heating of membranes to ΔT = 40 °C above gas temperature provides sufficient thermophoretic repulsion to prevent particle deposition and maintain transparency at high soot exposure, while non-heated identical membranes on the same die and at the same exposure are heavily contaminated.
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| 9. |
- Zhang, H., et al.
(author)
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Ageing hardening and corrosion resistance of Fe 60 Cr 18 Cu 3 (MnCoNiMoAlTi) 19 medium-entropy alloy
- 2023
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In: Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals. - 1004-0609. ; 33:8, s. 2622-2634
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Journal article (peer-reviewed)abstract
- Fe60Cr18Cu3(CoMnMoNiAlTi)19 medium-entropy stainless alloy (MEA) was prepared by vacuum arc furnace melting. The ageing hardening mechanism and corrosion resistance of alloy were studied. The results show that the MEA has simple BCC solid solution phase after solidification, due to the influence of medium-entropy effect. HRTEM results show that the high level of lattice distortion in the supersaturated BCC solid solution matrix leads to a high amount of nanometer-sized ordered B2 coherent precipitates after ageing treatment, and the maximum hardness of MESS after ageing reaches 621HV0.5. The resistance to corrosion in hot sulfuric acid and to pitting in the NaCl solution are both greatly improved compared with the conventional 17-4PH steel, as evidenced by more stable anodic passivation zone and significantly reduced corrosion dissolution rate in the MEA. XPS analyses results show that the multi-component passive film, which composes of high contents of anti-corrosion elements including Crhy3 +, Crox3 +, Cu+ox, Ti4ox+, Al3ox+ and Mo6ox+, is the main reason for the excellent pitting resistance and the reduced growth of pitting pit in the NaCl solution.
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| 10. |
- Chen, X, et al.
(author)
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Bismuth Effects on Electronic Levels in GaSb(Bi)/AlGaSb Quantum Wells Probed by Infrared Photoreflectance
- 2015
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In: Chinese Physics Letters. - 0256-307X .- 1741-3540. ; 32:6
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Journal article (peer-reviewed)abstract
- GaSb(Bi)/Al0.2Ga0.8Sb single quantum wells are characterized by a Fourier transform infrared spectrometerbased photoreflectance method at 77 K. Spatially direct and indirect transitions between the electronic levels at and above the effective band gap are well resolved. The shifts of the electronic levels with Bi incorporation are identified quantitatively. The results show that the upshift of the valence band edge is clarified to be dominant, while the Bi-induced downshift of the conduction band edge does exist and contributes to the band gap reduction in the GaSbBi quantum-well layer by (29±6)%.
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