| 1. |
- You, Xiaohu, et al.
(författare)
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Towards 6G wireless communication networks: vision, enabling technologies, and new paradigm shifts
- 2021
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Ingår i: Science China Information Sciences. - : Science Press. - 1674-733X .- 1869-1919. ; 64:1
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Forskningsöversikt (refereegranskat)abstract
- The fifth generation (5G) wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized, such as mass connectivity, ultra-reliability, and guaranteed low latency. However, 5G will not meet all requirements of the future in 2030 and beyond, and sixth generation (6G) wireless communication networks are expected to provide global coverage, enhanced spectral/energy/cost efficiency, better intelligence level and security, etc. To meet these requirements, 6G networks will rely on new enabling technologies, i.e., air interface and transmission technologies and novel network architecture, such as waveform design, multiple access, channel coding schemes, multi-antenna technologies, network slicing, cell-free architecture, and cloud/fog/edge computing. Our vision on 6G is that it will have four new paradigm shifts. First, to satisfy the requirement of global coverage, 6G will not be limited to terrestrial communication networks, which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle (UAV) communication networks, thus achieving a space-air-ground-sea integrated communication network. Second, all spectra will be fully explored to further increase data rates and connection density, including the sub-6 GHz, millimeter wave (mmWave), terahertz (THz), and optical frequency bands. Third, facing the big datasets generated by the use of extremely heterogeneous networks, diverse communication scenarios, large numbers of antennas, wide bandwidths, and new service requirements, 6G networks will enable a new range of smart applications with the aid of artificial intelligence (AI) and big data technologies. Fourth, network security will have to be strengthened when developing 6G networks. This article provides a comprehensive survey of recent advances and future trends in these four aspects. Clearly, 6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.
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| 2. |
- Liu, Yong-feng, et al.
(författare)
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Sulfur quantum dot as a fluorescent nanoprobe for Fe3+ ions : Uncovering of detection mechanism, high sensitivity, and large detection range
- 2023
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Ingår i: Journal of Luminescence. - : Elsevier. - 0022-2313 .- 1872-7883. ; 257
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Tidskriftsartikel (refereegranskat)abstract
- Sulfur quantum dots (SQDs), as a novel metal-free fluorescent material, are getting increasingly tremendous attention in metal ion detection, especially for Fe3+, due to the merits of antimicrobial potential, low toxicity, and exciting optoelectronic properties. However, sensing mechanism of SQD based fluorescent probe for Fe3+ is not clear yet, and high sensitivity and large detection range remain a challenge. Here, we report the synthesis of hydrophilic SQDs as a fluorescent nanoprobe for Fe3+ via a fluorescent turn-off mode. We systematically studied the quenching mechanism by ultraviolet–visible absorption spectra, steady-state and time-resolved photoluminescent spectra, and temperature-dependent quenching constants. Results unclearly evidenced the quenching behavior to both inner filter effect and static quenching. Furthermore, the nanoprobe presents a large detection range from 2.5 to 700 μM and a limit of detection low to 53.6 nM, both of which are the record performance to our knowledge. At last, it shows high selectivity toward Fe3+ and presents no ionic strength effect in the range of investigation, which enables surprising results for Fe3+ detection in deionized water with interference ion and real water samples.
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| 3. |
- Pan, Zhangcheng, et al.
(författare)
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Highly stable CsPbI3 perovskite quantum dots enabled by single SiO2 coating toward down-conversion light-emitting diodes
- 2023
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 13:13
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Tidskriftsartikel (refereegranskat)abstract
- All-inorganic CsPbI3 perovskite quantum dots (PeQDs) have sparked widespread research due to their excellent optoelectronic properties and facile synthesis. However, attaining highly stable CsPbI3 perovskite quantum dots (PeQDs) against heat and polar solvents still remains a challenge and hinders any further practical application. Here, by exploiting (3-aminopropyl) triethoxysilane (APTES) as the sole silica (SiO2) precursor, we report a one-step in situ synthesis of single SiO2-coated CsPbI3 (SiO2-CsPbI3) PeQDs, namely that one SiO2 particle only contains one CsPbI3 PeQD particle. The obtained SiO2-CsPbI3 PeQDs are cubic in shape, have a more uniform size distribution, and possess narrow emission, with near unit photoluminescence quantum yields of up to 97.5%. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the formation of SiO2 through the hydrolysis of APTES on the CsPbI3 PeQDs surface. Furthermore, they have a significantly improved stability against storage, heat, and ethanol. By combining purple-emission GaN light-emitting diodes, the SiO2-CsPbI3 PeQDs were successfully employed as down-conversion emitters and exhibited considerable enhanced luminous performance and excellent stability, demonstrating their promising future in the practical application of solid-state lighting fields.
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| 4. |
- Zhu, Xiaolin, et al.
(författare)
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Capping ligand engineering enables stable CsPbBr3 perovskite quantum dots toward white-light-emitting diodes
- 2023
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 62:23, s. 9190-9198
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Tidskriftsartikel (refereegranskat)abstract
- All-inorganic perovskite quantum dots (PeQDs) have sparked extensive research focus on white-light-emitting diodes (WLEDs), but stability and photoluminescence efficiency issues are still remain obstacles impeding their practical application. Here, we reported a facile one-step method to synthesize CsPbBr3 PeQDs at room temperature using branched didodecyldimethylammonium fluoride (DDAF) and short-chain-length octanoic acid as capping ligands. The obtained CsPbBr3 PeQDs have a near-unity photoluminescence quantum yield of 97% due to the effective passivation of DDAF. More importantly, they exhibit much improved stability against air, heat, and polar solvents, maintaining >70% of initial PL intensity. Making use of these excellent optoelectronic properties, WLEDs based on CsPbBr3 PeQDs, CsPbBr1.2I1.8 PeQDs, and blue LEDs were fabricated, which show a color gamut of 122.7% of the National Television System Committee standard, a luminous efficacy of 17.1 lm/W, with a color temperature of 5890 K, and CIE coordinates of (0.32, 0.35). These results indicate that the CsPbBr3 PeQDs have great practical potential in wide-color-gamut displays.
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