| 11. |
- Chen, Yuqing, et al.
(författare)
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Breaking solvation dominance of ethylene carbonate via molecular charge engineering enables lower temperature battery
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Low temperatures severely impair the performance of lithium-ion batteries, which demand powerful electrolytes with wide liquidity ranges, facilitated ion diffusion, and lower desolvation energy. The keys lie in establishing mild interactions between Li+ and solvent molecules internally, which are hard to achieve in commercial ethylene-carbonate based electrolytes. Herein, we tailor the solvation structure with low-ε solvent-dominated coordination, and unlock ethylene-carbonate via electronegativity regulation of carbonyl oxygen. The modified electrolyte exhibits high ion conductivity (1.46 mS·cm−1) at −90 °C, and remains liquid at −110 °C. Consequently, 4.5 V graphite-based pouch cells achieve ~98% capacity over 200 cycles at −10 °C without lithium dendrite. These cells also retain ~60% of their room-temperature discharge capacity at −70 °C, and miraculously retain discharge functionality even at ~−100 °C after being fully charged at 25 °C. This strategy of disrupting solvation dominance of ethylene-carbonate through molecular charge engineering, opens new avenues for advanced electrolyte design.
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| 12. |
- Dong, Yibo, et al.
(författare)
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Transfer-free, lithography-free and fast growth of patterned CVD graphene directly on insulators by using sacrificial metal catalyst
- 2018
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Ingår i: Nanotechnology. - : IOP Publishing. - 1361-6528 .- 0957-4484. ; 29:36
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Tidskriftsartikel (refereegranskat)abstract
- Chemical vapor deposited graphene suffers from two problems: transfer from metal catalysts to insulators, and photoresist induced degradation during patterning. Both result in macroscopic and microscopic damages such as holes, tears, doping, and contamination, translated into property and yield dropping. We attempt to solve the problems simultaneously. A nickel thin film is evaporated on SiO2 as a sacrificial catalyst, on which surface graphene is grown. A polymer (PMMA) support is spin-coated on the graphene. During the Ni wet etching process, the etchant can permeate the polymer, making the etching efficient. The PMMA/graphene layer is fixed on the substrate by controlling the surface morphology of Ni film during the graphene growth. After etching, the graphene naturally adheres to the insulating substrate. By using this method, transfer-free, lithography-free and fast growth of graphene realized. The whole experiment has good repeatability and controllability. Compared with graphene transfer between substrates, here, no mechanical manipulation is required, leading to minimal damage. Due to the presence of Ni, the graphene quality is intrinsically better than catalyst-free growth. The Ni thickness and growth temperature are controlled to limit the number of layers of graphene. The technology can be extended to grow other two-dimensional materials with other catalysts.
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| 13. |
- Fan, Xing, 1975-, et al.
(författare)
-
Admission control for switched real-time Ethernet : scheduling analysis versus network calculus
- 2005
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Ingår i: Proc. of the Swedish National Computer Networking Workshop (SNCNW’05), Halmstad, Sweden, Nov. 23-24, 2005. ; , s. 4 s.-
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Konferensbidrag (refereegranskat)abstract
- Many approaches have been developed to give an estimation of the upper bound of the end-to-end delay or the response-time for real-time application, e.g., the Network Calculus (NC) model and the scheduling analysis. In this paper, we present an approach based on scheduling analysis to support guaranteed real-time services over standard switched Ethernet. Furthermore, we conduct a comparative study between these two admission control schemes, our novel algorithm and an NC-based algorithm. The simulation analysis shows that our feasibility analysis gives up to 50% higher utilization than the popular NC. Another advantage of our solution is that no additional hardware or software modification of the switch and the underlying standard. In our proposal, the traffic differentiation mechanism introduced by the IEEE 802.1D/Q standard and the standard hardware-implemented First Come First Served (FCFS) priority queuing are used in the switch and the source nodes. We have derived a feasibility analysis algorithm to ensure that the real-time requirements can be met. The algorithm also gives, as a sub-result, the needed buffer space in the end nodes and the switch. Moreover, our feasibility analysis supports variable-sized frames and switches with different bit-rates ports.
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| 14. |
- Fan, Xu, et al.
(författare)
-
Effects of different supplementary cementitious materials on the performance and environment of eco-friendly mortar prepared from waste incineration bottom ash
- 2022
-
Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618. ; 356
-
Tidskriftsartikel (refereegranskat)abstract
- Municipal solid waste incineration bottom ash (MSWIBA) is a by-product produced by municipal waste incineration treatment. In this study, MSWIBA particle size distribution, chemical composition and particle shape were investigated and confirmed its value for reuse in the construction field and its good research potential. MSWIBA was used as fine aggregates, while coal fly ash (FA) and ground granulated blast furnace slag (GGBFS) were used as auxiliary cementitious materials to replace part of cement to manufacture the eco-friendly mortar (EFM). The effect of FA/GGBFS on the mechanical and microscopic properties of EFM with different material ratios was mainly investigated. And the analysis of the environmental friendliness and economy of this EFM was made. The results show that the combination of FA and GGBFS at the same time reduces the early mechanical properties of the mortar. However, the strength developed rapidly after 7 days, with an increase of more than 6 times the rate before 7 days. Compared with GGBFS, FA is more helpful in improving the mechanical properties of the EFM. After 28 days of full hydration, the hydration products within the EFM are numerous and well bonded to each other. Not only do these hydration products increase the mechanical strength of EFM, but they also successfully solidify the hazardous components in MSWIBA and reduce their negative environmental effects. In addition, the use of MSWIBA instead of sand for mortar preparation reduces energy consumption and CO2 emissions, and it reduces the cost by more than 50 %. This indicates that MSWIBA may perform well in the future development of the civil infrastructures. As well as recycling waste resources, it makes a valuable contribution to the development of green and sustainable building materials.
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| 15. |
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| 16. |
- Fan, Xing, 1975-, et al.
(författare)
-
Efficient Many-to-Many Real-Time Communication Using an Intelligent Ethernet Switch
- 2004
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Ingår i: Proceedings of the 7<sup>th</sup> International Symposium on Parallel Architectures, Algorithms and Networks, 2004. - Piscataway, N.J. : IEEE. - 0769521355 ; , s. 280-287
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a solution for efficient many-to-many communication over switched Ethernet. The performance of using an ordinary switch and an intelligent switch is compared, and the results of the analysis based on 100 Mbit/s fast Ethernet show that an intelligent switch used to handle many-to-many communication can give better performance (shorter latency and higher utilization) than an ordinary switch. We also extend the network to serve many-to-many traffic with real-time demands by adding a thin software layer to the intelligent Ethernet switch and the end-nodes. Earliest deadline first (EDF) scheduling is used.
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| 17. |
- Fan, Xing, 1975-, et al.
(författare)
-
Efficient Support for High Traffic-Volumes of Short-Message Real-Time Communication Using an Active Ethernet Switch
- 2004
-
Ingår i: Proceedings of the 10th International Conference on Real-time and Embedded Computing Systems and Applications (RTCSA’04). ; , s. 517-533
-
Konferensbidrag (refereegranskat)abstract
- There are several different types of communication traffic with real- time demands apparent in distributed industrial and embedded systems, for example, group communication and process synchronization. The length of these messages is often very short but the traffic volume might be really high. Standard network protocols do not normally reach very high utilization for such small messages. This paper presents a solution to efficiently support real-time short message communication over switched Ethernet. In our proposal, the Ethernet switch and the end-nodes are enhanced to combine several short messages into an Ethernet frame to improve the performance, and to give the short-message traffic real-time support on two levels, short-frame level and Ethernet frame level. Earliest Deadline First (EDF) scheduling is used in the switch and in the source nodes on both these two levels. We have characterized the performance of the network in terms of channel utilization and the number of accepted real-time channels, by simulations of the network assuming Fast Ethernet. We also show, by example, that we can reach an improvement of the possible short-message rate of 66%.
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| 18. |
- Fan, Xing, 1975-, et al.
(författare)
-
Guaranteed real-time communication in packet-switched networks with FCFS queuing
- 2009
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Ingår i: Computer Networks. - Amsterdam : North Holland. - 1389-1286 .- 1872-7069. ; 53:3, s. 400-417
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we propose a feasibility analysis of periodic hard real-time traffic in packet-switched networks using first come first served (FCFS) queuing but no traffic shapers. Our work constitutes a framework that can be adopted for real-time analysis of switched low-cost networks like Ethernet without modification of the standard network components. Our analysis is based on a flexible network and traffic model, e.g., variable-sized frames, arbitrary deadlines and multiple switches. The correctness of our real-time analysis and the tightness of it for network components in single-switch networks are given by theoretical proofs. The performance of the end-to-end real-time analysis is evaluated by simulations. Moreover, our conceptual and experimental comparison studies between our analysis and the commonly used Network Calculus (NC) shows that our analysis can achieve better performance than NC in many cases.
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| 19. |
- Fan, Xing, 1975-, et al.
(författare)
-
Guaranteed Real-Time Communication in Packet-Switched Networks with FCFS queuing : Analysis and Simulations
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this report, we present a real-time analytical framework and the performance evaluation on our analysis. We propose a feasibility analysis of periodic hard real-time traffic in packet-switched networks using First Come First Served (FCFS) queuing but no traffic shapers. We choose switched Ethernet as an example to present the idea of our analysis and our experimental evaluations in this report.The remainder of the report is organized as follows. In Chapter 2, we define the network models, important concepts and terminology for real-time analysis. Chapter 3 presents our real-time analysis for isolated network elements. Chapter 4 gives end-to-end real-time analysis. Chapter 5 presents the performance evaluation of our results by simulation and comparison study and summarizes this report.
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| 20. |
- Fan, Xing, 1975-, et al.
(författare)
-
Guaranteed Real-Time Services in Switched Ethernet Networks with Deadline Scheduling in the End Nodes
- 2004
-
Konferensbidrag (refereegranskat)abstract
- This paper proposes a switched Ethernet network that supports real-time communication with guaranteed bit rate and end-to-end delay bound. In our proposal, the source nodes use Earliest Deadline First (EDF) scheduling, while the switch uses First Come First Served (FCFS) to control periodic real-time traffic belonging to logical realtime connections. The schedulability condition is drawn and the end-to-end worst-case delay bound is derived for guaranteed real-time traffic, which also gives, as a sub-result, the needed buffer space in the switch. Moreover, different traffic classes are prioritized and put into different output queues in the end nodes and the switch, which minimizes the interference with other traffic when transmitting periodic time-critical messages. The solution requires no additional hardware or software modifications of the switch and the underlying standard. It is based purely on software implementation in the end nodes. Furthermore, the EDF scheduling strategy used in the source nodes allows good resource utilization, while the FCFS scheduling used in the switch limits the switch processing overhead. The paper presents simulation analysis for Fast Ethernet, which verifies our approach of guaranteeing real-time transmission at the same time as achieving high utilization.
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