| 1. |
- Zhang, Hui-ning, et al.
(författare)
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Carbothermic Reduction of Zinc and Iron Oxides in Electric Arc Furnace Dust
- 2014
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Ingår i: Journal of Iron and Steel Research International. - 1006-706X .- 2210-3988. ; 21:4, s. 427-432
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Tidskriftsartikel (refereegranskat)abstract
- The reduction of zinc and iron oxides from electric arc furnace dust (EAFD) by carbon was investigated at temperatures between 800 and 1300 °C. The analytic technique employed includes chemical analysis, X-ray fluorescence spectroscopy (XRF), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) equipped with X-ray energy dispersive spectrometry (EDS), and thermodynamic database FactSage 6. 2. It was found that the reduction of zinc and iron oxides depends largely on Boudouad reaction. At 900 °C, zinc exists in tested samples as ZnO, which is reduced in the temperature range of 1000 — 1100 °C. At 1100 °C, 99. 11% of the zinc is evaporated. The metallization ratio of Fe is 79. 19% at 1300 °C, as the content of Fe2+ is still 9. 40%. A higher temperature is thus required for a higher reduction degree of Fe oxides by solid or gaseous carbon
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| 2. |
- Li, Chao, et al.
(författare)
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Federated Hierarchical Trust-based Interaction Scheme for Cross-domain Industrial IoT
- 2023
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Ingår i: IEEE Internet of Things Journal. - : IEEE. - 2327-4662 .- 2372-2541. ; 10:1, s. 447-457
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Tidskriftsartikel (refereegranskat)abstract
- The Industrial Internet of Things (IIoT) is considered to be one of the most promising revolutionary technologies to increase productivity. With the refined development of manufacturing, the entire manufacturing process is split up into several areas of IoT production. Devices from different domains cooperate to perform the same task, which cause security problems in interacted communication among them. Existing authentication methods cause heavy key management overhead or rely on a trusted third party. It is imperative to protect privacy and ensure the credibility of the device during device interaction. This paper proposes a federated hierarchical trust interaction scheme (FHTI) for the cross-domain industrial IoT. It builds a low-privacy network platform through blockchain and protects the data privacy of the IIoT. A hierarchical trust mechanism based on federated detection is designed to realize the unified trust evaluation of cross-domain devices. A trusted cross-domain method based on device trust value is designed to ensure the security and trustworthiness of cross-domain devices. The simulation results show that the FHTI scheme can improve the speed of identity authentication and the detection accuracy of malicious devices.
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| 3. |
- Li, Fangfang, et al.
(författare)
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Efficient and Reversible Chemisorption of Carbon Dioxide with Dianionic-Functionalized Ionic Liquid-Based Solvents
- 2020
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 34:7, s. 8526-8533
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Tidskriftsartikel (refereegranskat)abstract
- Developing carbon dioxide (CO2) capture technologies has caused worldwide interest because of the baneful influence of CO2 on climate change as a main greenhouse gas. Ionic liquids (ILs) are considered as potential absorbents for CO2 capture because of their unique properties compared with current amine-based solvents. In this work, new dianionic-functionalized IL-based solvents, bi(1,8-diazabicyclo[5.4.0]undec-7-ene) dimethylhydantoin/ethylene glycol ([(DBUH)(2)][Dhyd]/EG), were designed and prepared for efficient and reversible chemisorption of CO2. Among the absorbents, [(DBUH)(2)][Dhyd]/EG with a mass ratio of 5:5 exhibited not only a high CO2 absorption capacity of 0.11 g CO2 /g absorbent at 20 degrees C and 0.10 MPa but also good recyclability. Spectroscopic characterizations and simulation calculations confirmed that the superior CO2 capacity may be attributed to the simultaneous reaction of CO(2 )with both the [Dhyd](2)- anion and deprotonated EG. The excellent CO2 absorption and regeneration performance imply that [(DBUH)(2)][Dhyd]/EG solvents may have great industrial application potentials.
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| 4. |
- Li, Yuhong, et al.
(författare)
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Enhancing the internet of things with knowledge-driven software-defined networking technology : Future perspectives
- 2020
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 20:12, s. 1-20
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Tidskriftsartikel (refereegranskat)abstract
- The Internet of Things (IoT) connects smart devices to enable various intelligent services. The deployment of IoT encounters several challenges, such as difficulties in controlling and managing IoT applications and networks, problems in programming existing IoT devices, long service provisioning time, underused resources, as well as complexity, isolation and scalability, among others. One fundamental concern is that current IoT networks lack flexibility and intelligence. A network-wide flexible control and management are missing in IoT networks. In addition, huge numbers of devices and large amounts of data are involved in IoT, but none of them have been tuned for supporting network management and control. In this paper, we argue that Software-defined Networking (SDN) together with the data generated by IoT applications can enhance the control and management of IoT in terms of flexibility and intelligence. We present a review for the evolution of SDN and IoT and analyze the benefits and challenges brought by the integration of SDN and IoT with the help of IoT data. We discuss the perspectives of knowledge-driven SDN for IoT through a new IoT architecture and illustrate how to realize Industry IoT by using the architecture. We also highlight the challenges and future research works toward realizing IoT with the knowledge-driven SDN.
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| 5. |
- Tian, Jian-jun, et al.
(författare)
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Influence of heat treatment on fracture and magnetic properties of radially oriented Sm 2 Co 17 permanent magnets
- 2007
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Ingår i: Transactions of Nonferrous Metals Society of China. - 1003-6326 .- 2210-3384. ; 17:3, s. 491-495
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Tidskriftsartikel (refereegranskat)abstract
- The quenching, fracture and aging treatment of radially oriented Sm2Co17 ring magnets were investigated. The results indicate that the ring magnets have obvious anisotropy of thermal expansion, which easily leads to the splits of the magnets during quenching. The fracture is brittle cleavage fracture. The difference (δa) of the expansion coefficient reaches the maximum value at 800–850 °C. So, various quenching processes at different steps are adopted in order to reduce the splits. When the magnets are aged. 1:5 phase precipitates from the 2:17 matrix phase and forms a cellular microstructure with 2:17 phase. BHmax and 3Hc reach the maximum value 226 kJ/m3 and 2170 kA/m after being aged at 850 °C for 4 h and 8 h, respectively. The aging treatment at 850 °C has little influence on remanence(Br), which can always keep a high value (≥1.0 T). Through appropriate heat treatment, the ring magnets have uniform cellular microstructure and excellent magnetic properties: Br1.0T, 3Hc≥2 100 kA/m, BHmax≥220 kJ/m3.
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| 6. |
- Yang, Chih-Wen, et al.
(författare)
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Epitaxial Growth and Determination of Band Alignment of Bi2Te3–WSe2 Vertical van der Waals Heterojunctions
- 2020
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Ingår i: ACS Materials Letters. - : American Chemical Society (ACS). - 2639-4979. ; 2:10, s. 1351-1359
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Tidskriftsartikel (refereegranskat)abstract
- Artificial heterojunctions formed by vertical stacking of dissimilar two-dimensional (2D) transition metal dichalcogenide (TMD) monolayer materials in a chosen sequence hold tantalizing prospects for futuristic atomically thin circuits. The emergence of 2D topological insulators (TI), including Bi2Te3, Bi2Se3, and Sb2Te3, represents a new class of 2D building blocks and can complement the existing artificial heterojunctions as a result of their intriguing surface states protected by the time-reversal symmetry. However, the determination of band alignments of such 2D TI/TMD vertical heterojunctions, the key parameter for designing HJ-based electronic/photonic devices, which lies in the development of epitaxy growth, remains in its infancy. Here, we demonstrate the epitaxy growth of 2D TI/TMD vertical heterojunctions comprised of Bi2Te3/WSe2 with atomically clean interfaces that are spectroscopically accessible, and theoretically tractable. Cross-sectional scanning transmission electron microscopy (STEM) images and the presence of interlayer-coupled characteristics from Raman spectroscopy collectively confirm the neat stacking of Bi2Te3/WSe2 with the absence of unwanted containments. Microbeam X-ray photoelectron spectroscopy (ΌXPS) measurement coupled with the density functional theory (DFT) calculations and electrical characteristics of field effect transistors quantitatively reveals the type-II alignment of vertically stacked of quintuple layers (QL) Bi2Te3/WSe2. Meanwhile, the type-III band emerges when transitioning to multi-quintuple layer (MQL) Bi2Te3/WSe2. The finding here provides a well-defined example of the epitaxy growth paradigm, the interlayer coupling-electronic properties relationship, for these emerging 2D TI/TMDs vertical heterojunctions. © 2020 American Chemical Society.
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| 7. |
- Yang, Hui, et al.
(författare)
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BrainIoT : Brain-Like Productive Services Provisioning with Federated Learning in Industrial IoT
- 2022
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Ingår i: IEEE Internet of Things Journal. - : IEEE. - 2327-4662. ; 9:3, s. 2014-2024
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Tidskriftsartikel (refereegranskat)abstract
- The Industrial Internet of Things (IIoT) accommodates a huge number of heterogeneous devices to bring vast services under a distributed computing scenarios. Most productive services in IIoT are closely related to production control and require distributed network support with low delay. However, the resource reservation based on gross traffic prediction ignores the importance of productive services and treats them as ordinary services, so it is difficult to provide stable low delay support for large amounts of productive service requests. For many productions, unexpected communication delays are unacceptable, and the delay may lead to serious production accidents causing great losses, especially when the productive service is security related. In this article, we propose a brain-like productive service provisioning scheme with federated learning (BrainIoT) for IIoT. The BrainIoT scheme is composed of three algorithms, including industrial knowledge graph-based relation mining, federated learning-based service prediction, and globally optimized resource reservation. BrainIoT combines production information into network optimization, and utilizes the interfactory and intrafactory relations to enhance the accuracy of service prediction. The globally optimized resource reservation algorithm suitably reserves resources for predicted services considering various resources. The numerical results show that the BrainIoT scheme utilizes interfactory relation and intrafactory relation to make an accurate service prediction, which achieves 96% accuracy, and improves the quality of service.
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| 8. |
- Zhang, Wei-Min, et al.
(författare)
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Synthesis of mesoporous ZnS synergistically templated by butylamine and alkanols
- 2012
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Ingår i: Microporous and Mesoporous Materials. - : Elsevier BV. - 1387-1811 .- 1873-3093. ; 147:1, s. 222-228
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Tidskriftsartikel (refereegranskat)abstract
- Pore size and pore volume adjustable mesoporous ZnS was synthesized through a co-template method, which was achieved by the combined interaction between butylamine and some alkanols with proper lengths of the straight carbon chain. The pore size for mesoporous ZnS templated by butyl amine alone was 4.29 nm, and could be enlarged to 6.96 and 8.33 nm respectively through adding certain amounts of hexanol and octanol. Correspondingly, the pore volume also exhibited an augmentation with increasing carbon chain lengths of alkanols from C6 to C8. However, the pore size and pore volume dropped abruptly when decanol was added as the auxiliary agent. The formation of mesopores for ZnS prepared using butylamine molecules as the only templating agent is considered to be attributed to the coordination between N atoms in amines and Zn2+ ions at the surfaces of zinc suphide. The templating effect of butylamines might be improved by adding hexanols and octanols to form aggregates through solubilization to tailor the pore size and pore volume of ZnS effectively, while the function of decanols for changing the porous structure is restricted by its low solubility.
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| 9. |
- Zhuang, Hui, et al.
(författare)
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Duplexer design and implementation for self-interference cancellation in full-duplex communications
- 2016
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Ingår i: European Signal Processing Conference, EUSIPCO 2016. - Piscataway, NJ : IEEE Computer Society Digital Library. - 9780992862657 ; , s. 125-129
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Konferensbidrag (refereegranskat)abstract
- The full-duplex (FD) based devices are capable of concurrently transmitting and receiving signals with a single frequency band. However, a severe self-interference (SI) due to the large difference between the power of the devices' own transmission and that of the signal of interest may be imposed on the FD based devices, thus significantly eroding the received signal-to-interference-plus-noise ratio (SINR). To implement the FD devices, the SI power must be sufficiently suppressed to provide a high-enough received SINR for satisfying the decoding requirement. In this paper, the design and implementation of the duplexer for facilitating SI cancellation in FD based devices are investigated, with a new type of duplexer (i.e. an improved directional coupler) designed and verified. It is shown that the SI suppression capability may be up to 36 dB by using the proposed design, which is much higher than that attainable in the commonly designed ferrite circulator
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