| 1. |
- Li, Xiaochun, et al.
(författare)
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Bidirectional associations of intellectual and social activities with cognitive function among middle-aged and elderly adults in China
- 2022
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327. ; 319, s. 83-89
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies evaluating the association between leisure activities and cognitive function produced conflicting results. Different types of leisure activities may have different effects on cognition, and very few studies have explored their bidirectional associations. Our study aimed to explore whether intellectual and social activities had bidirectional associations with cognitive function among the middle-aged and elderly adults in China. Methods: Data was derived from the China Health and Retirement Longitudinal Study. The data in this study were based on 11,549 participants aged 45 or older whose intellectual and social activities and cognitive function were assessed at baseline. Cross-lagged panel model was used to examine the temporal relationship of intellectual and social activities with cognitive function. Results: Totally, 5624 participants completed the third follow-up in 2018. The results showed that the better the cognitive function they had at baseline, the more intellectual activities they were engage in (β = 0.044, P < 0.001) and vice versa (β = 0.042, P = 0.001). Additionally, better cognitive function at baseline was significantly associated with more engagement in social activities (β = 0.028, P = 0.030); in contrast, higher engagement in social activities at baseline was not related to better cognitive function (β = −0.008, P = 0.523). Limitations: Engagement in social and intellectual activities was assessed via questionnaire. Conclusions: Our findings indicated that there was a bidirectional relationship between intellectual activities and cognitive function. However, participation in social activities did not slow down the decline in cognitive function. Participating in intellectual activities, compared to social activities, is especially beneficial for cognitive function.
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| 2. |
- Zhang, Li, et al.
(författare)
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13.6% Efficient Organic Dye-Sensitized Solar Cells by Minimizing Energy Losses of the Excited State
- 2019
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Ingår i: ACS Energy Letters. - : AMER CHEMICAL SOC. - 2380-8195. ; 4:4, s. 943-951
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Tidskriftsartikel (refereegranskat)abstract
- The electron-injection energy losses of dye-sensitized solar cells (DSSCs) are among the fundamental problems hindering their successful breakthrough application. Two triazatruxene (TAT)-based sensitizers, with one containing a flexible Z-type double bond and another a rigid single bond, coded as ZL001 and ZL003, respectively, have been synthesized and applied in DSSCs to probe the energy losses in the process of electron injection. Using time-resolved laser spectroscopic techniques in the kinetic study, ZL003 with the rigid single bond promotes much faster electron injection into the conductive band of TiO2 especially in the locally excited state (hot injection), which leads to higher electron density in TiO2 and a higher V-oc. The devices based on ZL003 exhibited a champion power conversion efficiency (PCE) of 13.6% with V-oc = 956 mV, J(sc) = 20.73 mA cm(-2), and FF = 68.5%, which are among the highest recorded results to date on single dye-sensitized DSSCs. An independent certified PCE of 12.4% has been obtained for devices based on ZL003.
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| 3. |
- Cheng, Ming, et al.
(författare)
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A Perylenediimide Tetramer-Based 3D Electron Transport Material for Efficient Planar Perovskite Solar Cell
- 2017
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Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 1:5
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Tidskriftsartikel (refereegranskat)abstract
- A perylenediimide (PDI) tetramer-based three dimensional (3D) molecular material, termed SFX-PDI4, has been designed, synthesized, and characterized. The low-lying HOMO and LUMO energy levels, high electron mobility and good film-formation property make it a promising electron transport material (ETM) in inverted planar perovskite solar cells (PSCs). The device exhibits a high power conversion efficiency (PCE) of 15.3% with negligible hysteresis, which can rival that of device based on PC61BM. These results demonstrate that three dimensional PDI-based molecular materials could serve as high performance ETMs in PSCs.
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| 4. |
- Li, Jiajia, et al.
(författare)
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Recent Applications of Ionic Liquids in Quasi-Solid-State Lithium Metal Batteries
- 2021
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Ingår i: Green Chemical Engineering. - : Elsevier. - 2666-9528. ; 2:3, s. 253-265
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Forskningsöversikt (refereegranskat)abstract
- Quasi-solid-state lithium metal batteries are considered as one of the most promising energy storage devices, and the application of ionic liquids (ILs) as a new generation of functionalized electrolyte components in lithium metal batteries has become one of the research focuses. In this review, the very recent research work related to using IL to develop quasi-solid-state electrolytes and their influences on the performances of quasi-solid-state lithium metal batteries were surveyed and summarized, suggesting that the introduction of ILs can improve the ionic conductivity, broaden the electrochemical stability window, and enhance the electrochemical stability of selected electrolytes. Moreover, using ILs to prepare high-performance electrodes with unique microstructures and uniform distribution of fillers were also introduced. The composite quasi-solid-state electrolytes were suggested as the mainstream of electrolytes in the future due to the combination of the advantages of inorganic and polymer quasi-solid-state electrolytes, and their development challenges in high energy and high safety quasi-solid-state lithium metal batteries were also discussed.
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| 5. |
- Wang, Weihan, et al.
(författare)
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Enhancing the Energy-Conversion Efficiency of Solid-State Dye-Sensitized Solar Cells with a Charge-Transfer Complex based on 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone
- 2018
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Ingår i: ENERGY TECHNOLOGY. - : John Wiley & Sons. - 2194-4288. ; 6:4, s. 752-758
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Tidskriftsartikel (refereegranskat)abstract
- As a champion hole-transporting material (HTM), 2,27,7-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene (Spiro-OMeTAD) has been widely used in solid-state dye-sensitized solar cells (ssDSCs). Owing to the low conductivity of Spiro-OMeTAD, a chemical doping strategy is commonly used to enhance its hole-transporting properties. In this study, we report a strong electron acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an additive for Spiro-OMeTAD along with its application in ssDSCs. We show that the conductivity of Spiro-OMeTAD increases from 5.31 x 10(-5) to 2.22 x 10(-4) Scm upon the addition of 0.04% DDQ, and the power conversion efficiency (PCE) of the ssDSCs also increases. By utilizing a donor-pi-acceptor sensitizer with a high coefficient and an HTM with an optimized doping ratio, we were able to achieve a high PCE of 6.37% for the ssDSCs under 10 0mWcm(-2) AM1.5G simulated illumination, in comparison to the PCE of the pristine device, which was only 3.50%. An increase in the application of benzoquinone-based materials for organic electronics is expected, especially for solar-cell applications.
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| 6. |
- Cao, Wei, et al.
(författare)
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Interaction With Social Robots : Improving Gaze Toward Face but Not Necessarily Joint Attention in Children With Autism Spectrum Disorder
- 2019
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Ingår i: Frontiers in Psychology. - : FRONTIERS MEDIA SA. - 1664-1078. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- It is widely recognized that robot-based interventions for autism spectrum disorders (ASD) hold promise, but the question remains as to whether social humanoid robots could facilitate joint attention performance in children with ASD. In this study, responsive joint attention was measured under two conditions in which different agents, a human and a robot, initiated joint attention via video. The participants were 15 children with ASD (mean age: 4.96 +/- 1.10 years) and 15 typically developing (TD) children (mean age: 4.53 +/- 0.90 years). In addition to analyses of fixation time and gaze transitions, a longest common subsequence approach (LCS) was employed to compare participants' eye movements to a predefined logical reference sequence. The fixation of TD toward agent's face was earlier and longer than children with ASD. Moreover, TD showed a greater number of gaze transitions between agent's face and target, and higher LCS scores than children with ASD. Both groups showed more interests in the robot's face, but the robot induced a lower proportion of fixation time on the target. Meanwhile participants showed similar gaze transitions and LCS results in both conditions, suggesting that they could follow the logic of the joint attention task induced by the robot as well as human. We have discussed the implications for the effects and applications of social humanoid robots in joint attention interventions.
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| 7. |
- Cao, Yuan, et al.
(författare)
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Hybrid Trusted/Untrusted Relay Based Quantum Key Distribution over Optical Backbone Networks
- 2021
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Ingår i: IEEE Journal on Selected Areas in Communications. - 0733-8716 .- 1558-0008. ; 39:9, s. 2701-2718
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Tidskriftsartikel (refereegranskat)abstract
- Quantum key distribution (QKD) has demonstrated a great potential to provide future-proofed security, especially for 5G and beyond communications. As the critical infrastructure for 5G and beyond communications, optical networks can offer a cost-effective solution to QKD deployment utilizing the existing fiber resources. In particular, measurement-device-independent QKD shows its ability to extend the secure distance with the aid of an untrusted relay. Compared to the trusted relay, the untrusted relay has obviously better security, since it does not rely on any assumption on measurement and even allows to be accessed by an eavesdropper. However, it cannot extend QKD to an arbitrary distance like the trusted relay, such that it is expected to be combined with the trusted relay for large-scale QKD deployment. In this work, we study the hybrid trusted/untrusted relay based QKD deployment over optical backbone networks and focus on cost optimization during the deployment phase. A new network architecture of hybrid trusted/untrusted relay based QKD over optical backbone networks is described, where the node structures of the trusted relay and untrusted relay are elaborated. The corresponding network, cost, and security models are formulated. To optimize the deployment cost, an integer linear programming model and a heuristic algorithm are designed. Numerical simulations verify that the cost-optimized design can significantly outperform the benchmark algorithm in terms of deployment cost and security level. Up to 25% cost saving can be achieved by deploying QKD with the hybrid trusted/untrusted relay scheme while keeping much higher security level relative to the conventional point-to-point QKD protocols that are only with the trusted relays.
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| 8. |
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| 9. |
- Cao, Yuan, et al.
(författare)
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Multi-Tenant Provisioning for Quantum Key Distribution Networks With Heuristics and Reinforcement Learning : A Comparative Study
- 2020
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Ingår i: IEEE Transactions on Network and Service Management. - : Institute of Electrical and Electronics Engineers (IEEE). - 1932-4537. ; 17:2, s. 946-957
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Tidskriftsartikel (refereegranskat)abstract
- Quantum key distribution (QKD) networks are potential to be widely deployed in the immediate future to provide long-term security for data communications. Given the high price and complexity, multi-tenancy has become a cost-effective pattern for QKD network operations. In this work, we concentrate on addressing the online multi-tenant provisioning (On-MTP) problem for QKD networks, where multiple tenant requests (TRs) arrive dynamically. On-MTP involves scheduling multiple TRs and assigning non-reusable secret keys derived from a QKD network to multiple TRs, where each TR can be regarded as a high-security-demand organization with the dedicated secret-key demand. The quantum key pools (QKPs) are constructed over QKD network infrastructure to improve management efficiency for secret keys. We model the secret-key resources for QKPs and the secret-key demands of TRs using distinct images. To realize efficient On-MTP, we perform a comparative study of heuristics and reinforcement learning (RL) based On-MTP solutions, where three heuristics (i.e., random, fit, and best-fit based On-MTP algorithms) are presented and a RL framework is introduced to realize automatic training of an On-MTP algorithm. The comparative results indicate that with sufficient training iterations the RL-based On-MTP algorithm significantly outperforms the presented heuristics in terms of tenant-request blocking probability and secret-key resource utilization.
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