| 1. |
- Xin, Zhiging, et al.
(författare)
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Scalable Fabrication of Conductive Lines by Patterned Wettability-Assisted Bar-Coating for Low Cost Paper-Based Circuits
- 2019
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Ingår i: Advanced Materials Interfaces. - : Wiley-VCH Verlag. - 2196-7350. ; 6:10
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Tidskriftsartikel (refereegranskat)abstract
- Patterning technology on the paper based on wettability difference for paper-based devices has attracted significant attention for its low cost, easy degradability, and high flexibility. Here, conductive lines are rapidly prepared by patterned wettability-assisted bar-coating for low cost paper-based circuits. It is found that 7 s plasma treatment time for acquiring wettability difference is optimal, which resulted in not only effective splitting of the liquid film but also highly consistent line width with mask. Moreover, low retention force of hydrophobic surface is imperative for self-confinement of the ink into hydrophilic areas, especially for ink with high solid content. The sheet resistance of patterns can reach 5 Ω ◻ −1 after 980 nm laser sintering when using 50 wt% solid content ink with 110 cP viscosity. The geometries of line patterns, i.e., line width and spacing, can be readily tuned by varying the designed size of mask patterns. As-prepared conductive patterns show good conductivity even after 500 bending cycles at 2 mm bending radius. It is believed that this study will provide deeper understanding of wettability difference-assisted patterning process and represents a general strategy for selective wetting, especially for high viscosity ink.
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| 2. |
- Li, Duan, et al.
(författare)
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Dense and strong ZrO2 ceramics fully densified in <15 min
- 2019
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Ingår i: Advances in Applied Ceramics. - : Informa UK Limited. - 1743-6753 .- 1743-6761. ; 118:1-2, s. 23-29
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Tidskriftsartikel (refereegranskat)abstract
- Crack-free zirconia ceramics were consolidated via sintering by intense thermal radiation (SITR) approach at 1600–1700°C for 3–5 min. The resulted ceramic bulks can achieve a relative density up to 99.6% with a grain size of 300–1200 nm. Their bending strength, Vickers hardness and indentation toughness values are up to 1244 ± 139 MPa, 13.3 ± 0.3 GPa and 5.5 ± 0.1 MPa m1/2, respectively. Quantitative Raman and XRD analysis show the presence of minor m phase on the natural surface (<7%), fracture surface (<10%) and indentation areas (<15%). It reveals that the SITR method is efficient for rapidly manufacturing zirconia ceramics with desired density, fine grained microstructure and good mechanical properties that are strongly demanded in dental applications.
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| 3. |
- Li, Jun, 1988, et al.
(författare)
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Bandwidth Slicing to Boost Federated Learning over Passive Optical Networks
- 2020
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Ingår i: IEEE Communications Letters. - : Institute of Electrical and Electronics Engineers Inc.. - 1089-7798 .- 1558-2558. ; 24:7, s. 1492-1495
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Tidskriftsartikel (refereegranskat)abstract
- During federated learning (FL) process, each client needs to periodically upload local model parameters and download global model parameters to/from the central server, thus requires efficient communications. Meanwhile, passive optical network (PON) is promising to support fog computing where FL tasks can be executed and the traffic generated by FL needs to be transmitted together with other types of traffic for broadband access. In this letter, a bandwidth slicing algorithm in PONs is introduced for efficient FL, in which bandwidth is reserved for the involved ONUs collaboratively and mapped into each polling cycle. Results reveal that the proposed bandwidth slicing significantly improves training efficiency while achieving good learning accuracy for the FL task running over the PON.
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| 4. |
- Li, Jun, et al.
(författare)
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Delay-aware bandwidth slicing for service migration in mobile backhaul networks
- 2019
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Ingår i: Journal of Optical Communications and Networking. - : Institute of Electrical and Electronics Engineers Inc.. - 1943-0620 .- 1943-0639. ; 11:4, s. B1-B9
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Tidskriftsartikel (refereegranskat)abstract
- Fog computing is expected to be integrated with communication infrastructure, giving rise to the concept of fog-enhanced radio access networks (FeRANs) to support various mission-critical applications. Such architecture brings computation capabilities closer to end users, thereby reducing the communication latency to access services. In the context of FeRAN, service migration is needed to tackle limited resources in a single fog node and to provide continuous service for mobile end users. To support service migration, high capacity and low latency are required in mobile backhaul networks. Passive optical networks can be a promising solution for such mobile back-haul, in which bandwidth is shared by both migration traffic and that which is not associated with service migration. In this paper, we propose a bandwidth slicing mechanism, in which the bandwidth can be provisioned to the migration traffic and non-migration traffic dynamically and effectively to meet their different delay requirements. Simulation results verify that the proposed delay-aware bandwidth slicing scheme can handle the migration traffic properly, i.e., sending it within a required time threshold, while limiting the impact of the migration traffic on the latency and jitter of the non-migration traffic, particularly that with high priority.
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| 5. |
- Li, Jun, et al.
(författare)
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Service Migration in Fog Computing Enabled Cellular Networks to Support Real-Time Vehicular Communications
- 2019
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 7, s. 13704-13714
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Tidskriftsartikel (refereegranskat)abstract
- Driven by the increasing number of connected vehicles and related services, powerful communication and computation capabilities are needed for vehicular communications, especially for real-time and safety-related applications. A cellular network consists of radio access technologies, including the current long-term evolution (LTE), the LTE advanced, and the forthcoming 5th generation mobile communication systems. It covers large areas and has the ability to provide high data rate and low latency communication services to mobile users. It is considered the most promising access technology to support real-time vehicular communications. Meanwhile, fog is an emerging architecture for computing, storage, and networking, in which fog nodes can be deployed at base stations to deliver cloud services close to vehicular users. In fog computing-enabled cellular networks, mobility is one of the most critical challenges for vehicular communications to maintain the service continuity and to satisfy the stringent service requirements, especially when the computing and storage resources are limited at the fog nodes. Service migration, relocating services from one fog server to another in a dynamic manner, has been proposed as an effective solution to the mobility problem. To support service migration, both computation and communication techniques need to be considered. Given the importance of protocol design to support the mobility of the vehicles and maintain high network performance, in this paper, we investigate the service migration in the fog computing-enabled cellular networks. We propose a quality-of-service aware scheme based on the existing handover procedures to support the real-time vehicular services. A case study based on a realistic vehicle mobility pattern for Luxembourg scenario is carried out, where the proposed scheme, as well as the benchmarks, are compared by analyzing latency and reliability as well as migration cost.
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| 6. |
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| 7. |
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| 8. |
- Yang, Hanmin, 1992-, et al.
(författare)
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Distributed electrified heating for efficient hydrogen production
- 2024
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Ingår i: Nature Communications. - : Nature Research. - 2041-1723. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- This study introduces a distributed electrified heating approach that is able to innovate chemical engineering involving endothermic reactions. It enables rapid and uniform heating of gaseous reactants, facilitating efficient conversion and high product selectivity at specific equilibrium. Demonstrated in catalyst-free CH4 pyrolysis, this approach achieves stable production of H2 (530 g h−1 L reactor−1) and carbon nanotube/fibers through 100% conversion of high-throughput CH4 at 1150 °C, surpassing the results obtained from many complex metal catalysts and high-temperature technologies. Additionally, in catalytic CH4 dry reforming, the distributed electrified heating using metallic monolith with unmodified Ni/MgO catalyst washcoat showcased excellent CH4 and CO2 conversion rates, and syngas production capacity. This innovative heating approach eliminates the need for elongated reactor tubes and external furnaces, promising an energy-concentrated and ultra-compact reactor design significantly smaller than traditional industrial systems, marking a significant advance towards more sustainable and efficient chemical engineering society.
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