| 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. |
- Jia, Xue, et al.
(författare)
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CsPb(IxBr1-x)(3) solar cells
- 2019
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Ingår i: Science Bulletin. - : ELSEVIER. - 2095-9273. ; 64:20, s. 1532-1539
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Tidskriftsartikel (refereegranskat)abstract
- Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell (PSC) becomes a promising candidate for next-generation high-efficiency solar cells. The power conversion efficiency (PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)(3) and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)(3) solar cells and outline possible directions to further improve the device performance. (C) 2019 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.
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| 3. |
- Tong, Yang, et al.
(författare)
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Progress of the key materials for organic solar cells
- 2020
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Ingår i: Science in China Series B. - Beijing, China : SCIENCE PRESS. - 1674-7291 .- 1869-1870. ; 63:6, s. 758-765
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Forskningsöversikt (refereegranskat)abstract
- Organic solar cells have attracted academic and industrial interests due to the advantages like lightweight, flexibility and roll-to-roll fabrication. Nowadays, 18% power conversion efficiency has been achieved in the state-of-the-art organic solar cells. The recent rapid progress in organic solar cells relies on the continuously emerging new materials and device fabrication technologies, and the deep understanding on film morphology, molecular packing and device physics. Donor and acceptor materials are the key materials for organic solar cells since they determine the device performance. The past 25 years have witnessed an odyssey in developing high-performance donors and acceptors. In this review, we focus on those star materials and milestone work, and introduce the molecular structure evolution of key materials. These key materials include homopolymer donors, D-A copolymer donors, A-D-A small molecular donors, fullerene acceptors and nonfullerene acceptors. At last, we outlook the challenges and very important directions in key materials development.
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| 4. |
- Fan, Zhiwen, et al.
(författare)
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Porous Ionic Network/CNT Composite Separator as a Polysulfide Snaring Shield for High Performance Lithium–Sulfur Battery
- 2023
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Ingår i: Macromolecular rapid communications. - 1022-1336 .- 1521-3927. ; 44:24
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Tidskriftsartikel (refereegranskat)abstract
- Lithium–sulfur (Li–S) battery features a high theoretical energy density, but the shuttle of soluble polysulfides between the two electrodes often results in a rapid capacity decay. Herein, a straightforward electrostatic adsorption strategy based on a cross-linked polyimidazolium separator as a snaring shield of polysulfides is reported, which suppresses the undesirable migration of polysulfides to the anode. The porous ionic network (PIN)-modified carbon nanotubes (CNTs) are successfully prepared and coated onto a commercial porous polypropylene membrane in a vacuum-filtration step. The favorable affinity of the imidazolium ring toward polysulfide via the polar interaction and the electrostatic effect of ions mitigates the undesirable shuttle of polysulfides in the electrolyte, improving the Li─S battery in terms of rate performance and cycling life. Compared to the reference PIN-free CNT-coated separator, the PIN/CNT-coated one has an increased initial capacity of 1.3 folds (up to 1394.8 mAh g−1 for PIN/CNT/PP-3) at 0.1 C.
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| 5. |
- Gao, Chan, et al.
(författare)
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Defect evolution behaviors from single sulfur point vacancies to line vacancies in monolayer molybdenum disulfide
- 2021
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 23:35, s. 19525-19536
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Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional monolayer transition metal dichalcogenides (TMDs) are promising candidates for many novel nanoelectronic and optoelectronic applications due to their exceptional electronic, optical, chemical and mechanical properties. Experimentally, single chalcogen point vacancies caused by electron beam irradiation are found to agglomerate into line vacancy defects in monolayer TMDs. Herein, the corresponding defect evolution behaviors from single sulfur point vacancies to line vacancies in the monolayer molybdenum disulfide (MoS2) have been systematically studied using molecular dynamics and first principles calculations. The experimental observations of the defect evolution from single sulfur point vacancies to line vacancies are reproduced at the atomic level. The results indicate that the di-vacancy line defect and a point vacancy separated by a sulfur atom in a line evolve into tri-vacancy line defects, and the di-vacancy line defects can rotate 60 degrees clockwise or counterclockwise. Moreover, two adjacent di-vacancy line defects with an angle of 120 degrees can evolve into tri-vacancy line defects. High temperature and large vacancy concentrations promote the defect evolution from point vacancies to line vacancies. Intriguingly, compared with the randomly distributed point vacancy defects, the line vacancy defects formed after the defect evolution significantly decrease the mechanical properties, such as the ultimate strength, ultimate strain and Young's modulus of monolayer MoS2. In addition, the mechanical properties decrease with increasing vacancy concentration and temperature for the final configurations after defect evolution in monolayer MoS2 with different vacancy concentrations at different temperatures. The band gaps of monolayer MoS2 with line vacancy defects are smaller than those with randomly distributed point vacancy defects. Therefore, our study clarifies the defect evolution behaviors from single sulfur point vacancies to line vacancies in monolayer MoS2 and opens an opportunity for the novel nanoelectronic and optoelectronic applications of monolayer TMDs.
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| 6. |
- Gao, Chan, et al.
(författare)
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Synergistic vacancy defects and mechanical strain for the modulation of the mechanical, electronic and optical properties of monolayer tungsten disulfide
- 2021
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 23:10, s. 6298-6308
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Tidskriftsartikel (refereegranskat)abstract
- Monolayer transition metal dichalcogenides (TMDs) are the potential candidate materials in nanoelectronic and optoelectronic applications due to their unique physical and chemical properties. Although both defect and strain greatly alter the structural, physical and chemical properties of monolayer TMDs, the defective monolayer TMDs under applied strain have not been adequately studied. In this paper, the synergistic effects of sulfur vacancy defects and mechanical strain on the mechanical, electronic and optical properties of monolayer tungsten disulfide (WS2) have been systematically studied using first principles density functional theory. The results indicate that the sulfur vacancy formation energy increases linearly with increasing sulfur vacancy concentration under different strains. The strain energy and stress of monolayer WS2 with different sulfur vacancy concentrations increase with increasing applied strain in the strain range of -10% to 10%. The band gap of monolayer WS2 decreases with increasing sulfur vacancy concentration under different strains. Moreover, compared with unstrained conditions, 5% compressive strain increases the band gap at a larger vacancy concentration and the case is just opposite at a smaller vacancy concentration, while 5% tensile strain decreases the band gap. The band gap of monolayer WS2 with different sulfur vacancy concentrations firstly increases and then shrinks with increasing applied strain under compressive strain, whereas it decreases monotonically under tensile strain in the strain range of -10% to 10%. In the visible-light wavelength region, the out-of-plane absorption coefficient under different strains increases with increasing sulfur vacancy concentration. Furthermore, 5% compressive strain enhances the absorption coefficient and 5% tensile strain decreases the absorption coefficient. Hence, the synergistic effects of sulfur vacancy defects and mechanical strain in monolayer TMDs can open new avenues for their applications in nanoelectronic and optoelectronic devices.
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| 7. |
- Huang, Hongyun, et al.
(författare)
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Clinical Cell Therapy Guidelines for Neurorestoration (IANR/CANR 2017)
- 2018
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Ingår i: Cell Transplantation. - : SAGE Publications. - 0963-6897 .- 1555-3892. ; 27:2, s. 310-324
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Forskningsöversikt (refereegranskat)abstract
- Cell therapy has been shown to be a key clinical therapeutic option for central nervous system diseases or damage. Standardization of clinical cell therapy procedures is an important task for professional associations devoted to cell therapy. The Chinese Branch of the International Association of Neurorestoratology (IANR) completed the first set of guidelines governing the clinical application of neurorestoration in 2011. The IANR and the Chinese Association of Neurorestoratology (CANR) collaborated to propose the current version "Clinical Cell Therapy Guidelines for Neurorestoration (IANR/CANR 2017)". The IANR council board members and CANR committee members approved this proposal on September 1, 2016, and recommend it to clinical practitioners of cellular therapy. These guidelines include items of cell type nomenclature, cell quality control, minimal suggested cell doses, patient-informed consent, indications for undergoing cell therapy, contraindications for undergoing cell therapy, documentation of procedure and therapy, safety evaluation, efficacy evaluation, policy of repeated treatments, do not charge patients for unproven therapies, basic principles of cell therapy, and publishing responsibility.
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| 8. |
- Li, Yadi, et al.
(författare)
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Virtual and In vitro bioassay screening of phytochemical inhibitors from flavonoids and isoflavones against Xanthine oxidase and Cyclooxygenase-2 for gout treatment
- 2013
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Ingår i: Chemical Biology and Drug Design. - : John Wiley & Sons. - 1747-0277 .- 1747-0285. ; 81:4, s. 537-544
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Tidskriftsartikel (refereegranskat)abstract
- Synthetic drugs such as allopurinol and benzbroarone are commonly used to treat the complex pathogenesis of gout, a metabolic disease that results from an inflammation of the joints caused by precipitation of uric acid. We seek to discover novel phytochemicals that could treat gout, by targeting the xanthine oxidase (XO) and cyclooxygenase 2 (COX-2) enzymes. In this study, we report the screening of 9 compounds of flavonoids from the ZINC and PubChem databases (containing 2,092 flavonoids) using the iGEMDOCK software tool against the XO and COX-2 3D protein structures. Each compound was also evaluated by an in vitro bioassay testing the inhibition of XO and COX-2. Myricetin and luteolin were found to be the potential dual inhibitors of XO and COX-2 as demonstrated by IC50: 62.7 and 3.29μg/mL (XO) / 70.8 and 16.38μg/mL (COX-2), respectively. In addition, structure activity relationships and other important factors of the flavonoids binding to the active site of XO and COX-2 were discussed, which is expected for further rational drug design.
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| 9. |
- Song, Luying, et al.
(författare)
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Intra- and Inter-Self-Assembly of Identical Supramolecules on Silver Surfaces
- 2022
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Ingår i: The Journal of Physical Chemistry Letters. - : AMER CHEMICAL SOC. - 1948-7185. ; 13:38, s. 8902-8907
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembly of identical organometallic supra -molecules into ordered superstructures is of great interest in both chemical science and nanotechnology due to its potential to generate neoteric properties through collective effects. In this work, we demonstrate that large-scale self-organization of atomically precise organometallic supramolecules can be achieved through cascaded on-surface chemical reactions, by the combination of intra-and inter-supramolecular interactions. Supramolecules with defined size and shape are first built through intramolecular reaction and intermolecular metal coordination, followed by the formation of well-ordered two-dimensional arrays with the assistance of Br atoms by-C-HmiddotmiddotmiddotBr interactions. The mechanism of this process has been investigated from the perspectives of thermodynamics and kinetics.
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| 10. |
- Wu, Cary, et al.
(författare)
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Chinese Citizen Satisfaction with Government Performance during COVID-19
- 2021
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Ingår i: Journal of Contemporary China. - : Informa UK Limited. - 1067-0564 .- 1469-9400. ; 30:132, s. 930-944
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Tidskriftsartikel (refereegranskat)abstract
- While foreign pundits have alternatively blamed and praised the Chinese government’s handling of the COVID-19 virus, little is known about how citizens within China understand this performance. This article considers how satisfied Chinese citizens are with their government’s performance during the COVID-19 pandemic. It first considers the impact of authoritarian control, political culture, and/or actual government performance on citizen satisfaction. Then, it tests the consequences of satisfaction and specifically whether citizen satisfaction leads to greater trust. Analyzing data from the first post-COVID survey of its kind (n = 19,816) conducted from April 22 to 28 April 2020, the authors find that Chinese citizens have an overall high level of satisfaction, but that this satisfaction drops with each lower level of government. Further, authoritarian control, political culture, and awareness of government performance all contribute to citizen satisfaction and this in turn, has enhanced public support for the Chinese government.
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