| 1. |
- Zhang, Lixiu, et al.
(författare)
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Advances in the Application of Perovskite Materials
- 2023
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Ingår i: NANO-MICRO LETTERS. - : SHANGHAI JIAO TONG UNIV PRESS. - 2311-6706. ; 15:1
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Forskningsöversikt (refereegranskat)abstract
- Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices (solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices (artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices.
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| 2. |
- Zhao, Xue, et al.
(författare)
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Two-dimensional BCN matrix inlaid with single-atom-Cu driven electrochemical nitrate reduction reaction to achieve sustainable industrial-grade production of ammonia
- 2021
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Ingår i: APPLIED MATERIALS TODAY. - : Elsevier. - 2352-9407. ; 25
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical methods have been proven to effectively eliminate nitrates in sewage and convert them into high value-added ammonia products. Here, after annealing treatment of metal boron cluster organic polymers formed by the combination of 1,10-phenanthroline, Cu2+ and closo-[B12H12](2)(-), a Cu single-atom doped BCN (B-doped CN) with a diamond-shaped nanosheet structure was obtained. In the electrochem-ical reduction reaction of nitrate, BCN-Cu exhibits excellent catalytic activity, specifically: 1) the ammonia yield rate reached as high as 498.85 mu g h(-1) cm(-2), 1047.14 mu g h(-1) cm(-2), 1900.07 mu g h(-1) cm(-2) and 3358.74 mu g h(-1) cm(-2) at -0.3 V, -0.4 V, -0.5 V and -0.6 V vs reversible hydrogen electrode, respectively, and Faradaic efficiency is 95.90%, 97.28%, 98.23% and 97.37%; 2) after repeated use of BCN-Cu 10 times or continuous operation for 16 h, the activity against electrochemical reduction reaction of nitrate anions is almost unchanged. The (NO3-)-N-15 isotopic labeling experiment proved that the detected NH3 comes from the reduction of NO3- on BCN-Cu. Control experiments show that the presence of Cu determines whether BCN-Cu has the possibility of catalyzing electrochemical reduction reactions of nitrate, and the presence of the B element enhances the catalytic activity of BCN-Cu. Density functional calculations indicate that in the water phase the process of reducing NO3- to NH3 on Cu-0 is an exothermic reaction, and that the adsorption process of NO3- on Cu-0 is the rate-determining step.
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| 3. |
- Cheng, Liu, et al.
(författare)
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EEG-CLNet : Collaborative Learning for Simultaneous Measurement of Sleep Stages and OSA Events Based on Single EEG Signal
- 2023
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : IEEE. - 0018-9456 .- 1557-9662. ; 72
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Tidskriftsartikel (refereegranskat)abstract
- Sleep-stage and apnea-hypopnea index (AHI) are the most important metrics in the diagnosis of sleep syndrome disease. In previous studies, these two tasks are usually implemented separately, which is both time- and resource-consuming. In this work, we propose a novel single electroencephalogram (EEG)-based collaborative learning network (EEG-CLNet) for simultaneous sleep staging and obstructive sleep apnea (OSA) event detection through multitask collaborative learning. The EEG-CLNet regards different tasks as a common unit to extract features from intragroups via both local parameter sharing and cross-task knowledge distillation (CTKD), rather than just sharing parameters or shortening the distance between different tasks. Our approach has been validated on two datasets with the same or better performance than other methods. The experimental results show that our method achieves a performance gain of 1%-5% compared with the baseline. Compared to previous works where two or even more models were required to perform sleep staging and OSA event detection, the EEG-CLNet could reduce the total number of model parameters and facilitate the model to mine the hidden relationships between different task semantic information. More importantly, it effectively alleviates the task bias problem in hard parameter sharing. As a consequence, this approach has notable potential to be a solution for a lightweight wearable sleep monitoring system in the future.
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| 4. |
- Peng, Yan, et al.
(författare)
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Cu Nanoparticle-Decorated Boron-Carbon-Nitrogen Nanosheets for Electrochemical Determination of Chloramphenicol
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:25, s. 28956-28964
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, irregular Cu nanoparticle-decorated boron-carbon-nitrogen (Cu-BCN) nanosheets were successfully synthesized. A Cu-BCN dispersion was deposited on a bare glassy carbon electrode (GCE) to prepare an electrochemical sensor (Cu-BCN/GCE) for the detection of chloramphenicol (CAP) in the environment. Cu-BCN was characterized using high-resolution scanning transmission electron microscopy (HRSTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and X-ray photoelectron spectroscopy (XPS). The performance of the Cu-BCN/GCE was studied using electrochemical impedance spectroscopy (EIS), and its advantages were proven by electrode comparison. Differential pulse voltammetry (DPV) was used to optimize the experimental conditions, including the amount of Cu-BCN deposited, enrichment potential, deposition time, and pH of the electrolyte. A linear relationship between the CAP concentration and current response was obtained under the optimized experimental conditions, with a wide linear range and a limit of detection (LOD) of 2.41 nmol/L. Cu-BCN/GCE exhibited high stability, reproducibility, and repeatability. In the presence of various organic and inorganic species, the influence of the Cu-BCN-based sensor on the current response of CAP was less than 5%. Notably, the prepared sensor exhibited excellent performance in real-water samples, with satisfactory recovery.
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| 5. |
- Qi, Di, et al.
(författare)
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Climate change drives rapid decadal acidification in the Arctic Ocean from 1994 to 2020
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 377:6614, s. 1544-1550
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Tidskriftsartikel (refereegranskat)abstract
- The Arctic Ocean has experienced rapid warming and sea ice loss in recent decades, becoming the first open-ocean basin to experience widespread aragonite undersaturation [saturation state of aragonite (Warag) < 1]. However, its trend toward long-term ocean acidification and the underlying mechanisms remain undocumented. Here, we report rapid acidification there, with rates three to four times higher than in other ocean basins, and attribute it to changing sea ice coverage on a decadal time scale. Sea ice melt exposes seawater to the atmosphere and promotes rapid uptake of atmospheric carbon dioxide, lowering its alkalinity and buffer capacity and thus leading to sharp declines in pH and Warag. We predict a further decrease in pH, particularly at higher latitudes where sea ice retreat is active, whereas Arctic warming may counteract decreases in Warag in the future.
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| 6. |
- Zhang, Jibin, et al.
(författare)
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Ligand-Induced Cation-p Interactions Enable High-Efficiency, Bright, and Spectrally Stable Rec. 2020 Pure-Red Perovskite Light-Emitting Diodes
- 2023
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Tidskriftsartikel (refereegranskat)abstract
- Achieving high-performance perovskite light-emitting diodes (PeLEDs) with pure-red electroluminescence for practical applications remains a critical challenge because of the problematic luminescence property and spectral instability of existing emitters. Herein, high-efficiency Rec. 2020 pure-red PeLEDs, simultaneously exhibiting exceptional brightness and spectral stability, based on CsPb(Br/I)(3) perovskite nanocrystals (NCs) capping with aromatic amino acid ligands featuring cation-pi interactions, are reported. It is proven that strong cation-pi interactions between the PbI6-octahedra of perovskite units and the electron-rich indole ring of tryptophan (TRP) molecules not only chemically polish the imperfect surface sites, but also markedly increase the binding affinity of the ligand molecules, leading to high photoluminescence quantum yields and greatly enhanced spectral stability of the CsPb(Br/I)(3) NCs. Moreover, the incorporation of small-size aromatic TRP ligands ensures superior charge-transport properties of the assembled emissive layers. The resultant devices emitting at around 635 nm demonstrate a champion external quantum efficiency of 22.8%, a max luminance of 12 910 cd m(-2), and outstanding spectral stability, representing one of the best-performing Rec. 2020 pure-red PeLEDs achieved so far.
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| 7. |
- Zhao, Xue, et al.
(författare)
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Copper confined in vesicle-like BCN cavities promotes electrochemical reduction of nitrate to ammonia in water
- 2021
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 9:41, s. 23675-23686
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical methods to convert high-concentration nitrates present in sewage into high-value-added ammonia do not just alleviate the problem of environmental pollution but also provide less energy-intensive alternatives to the Haber-Bosch process. In this work, a metal-boron organic polymer precursor was annealed at high temperature to obtain copper nanoparticles encapsulated in a vesicle-like BCN matrix (BCN@Cu). In the electrochemical reduction of nitrate (E-NIRR), this species exhibited excellent catalytic activity. Specifically, the ammonia yields of BCN@Cu under applied potentials of -0.3 V, -0.4 V, -0.5 V, and -0.6 V versus the reversible hydrogen electrode were 271.1 mu mol h(-1) mg(cat.)(-1), 354.8 mu mol h(-1) mg(cat.)(-1), 435.6 mu mol h(-1) mg(cat.)(-1), and 576.2 mu mol h(-1) mg(cat.)(-1), respectively, and the corresponding Faraday efficiencies were 86.3%, 88.0%, 89.3%, and 88.9%. Isotope labeling experiments with (NO3-)-N-15 confirmed that the detected ammonia had originated from the electrochemical reduction of NO3- on the catalyst surface. Moreover, the E-NIRR activity of BCN@Cu remained high even after using it ten consecutive times or 20 h of continuous operation, suggesting the practicality of the industrial application of BCN@Cu. The presence of copper was key in determining BCN@Cus E-NIRR activity, while the presence of boron greatly improved its catalytic performance. Furthermore, density functional theory calculations indicated that BCN does not itself promote the reaction but rather assists the dispersion of Cu nanoparticles, thereby expanding the catalysts active surface area.
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| 8. |
- Zhao, Xue, et al.
(författare)
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Hydrophobic boron organic polymers : Ultra-high capacity of enrichment and storage for chloroform
- 2020
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Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 385
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Tidskriftsartikel (refereegranskat)abstract
- Chloroform, a superstar widely applied as solvent, extractant, refrigerating fluid and adhesive, faces storage risks and environmental pressures. Herein, a brand-new strategy for storing and enriching chloroform is designed. It is shown that stable boron organic polymers BOPS-S3 with excellent hydrophobicity can be facilely prepared by combining Na-2[B12H12] and amphiphilic HBPB-14 molecules. The unique molecular structure of such as prepared polymers endows strong affinity with chloroform. BOPS-S3 possesses an ultra-high adsorption capacity of 46.9 g.g(-1) toward liquid chloroform, with a resulting gel that maintains a low volatilization rate. In addition, a stainless mesh coating with BOPS-S3 is shown to excellently remove chloroform vapor, likewise BOPS-S3 is shown efficient for removal of chloroform traces in water, with a residual amount lower than the allowable concentration in drinking water defined by the World Health Organization. This work provides a novel approach to store chloroform in transportation or other unstable conditions with unprecedented ramifications.
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| 9. |
- Zhao, Xue, et al.
(författare)
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Simultaneous anchoring of Ni nanoparticles and single-atom Ni on BCN matrix promotes efficient conversion of nitrate in water into high-value-added ammonia
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 433:Part 2
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical synthesis of ammonia driven by clean energy is expected to realize the supply of ammonia for distributed production of industry and agriculture. Here, nickel nanoparticles and nickel in the form of single atoms were simultaneously anchored on the electrochemically active carrier BCN matrix through a structured domain strategy, which realized a high-efficiency, high-value-added, conversion of nitrate in sewage. Specifically, the electrochemical nitrate reduction reaction (NIRR) driven by BCN@Ni in alkaline media achieves an ammonia yield rate as high as 2320.2 μg h−1 cm−2 (at −0.5 V vs RHE), and Faraday efficiency as high as 91.15% (at −0.3 V vs RHE). Even in neutral and acidic media, the ammonia yield rates of NIRR driven by BCN@Ni are as high as 1904.2 μg h−1 cm−2 and 2057.4 μg h−1 cm−2, respectively (at −0.4 V vs RHE). The 15NO3- isotope labeling experiment verified that the recorded ammonia all came from the electrochemical reduction of NO3– on BCN@Ni. Density functional theory (DFT) calculations show that both nano-Ni and single-atom Ni in BCN@Ni have the ability to electrochemically convert NO3– into NH3, and that the addition of BCN can further promote the NIRR on Ni.
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| 10. |
- Anani, Adi, 1944-, et al.
(författare)
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QoS-guaranteed packet scheduling in wireless networks
- 2009
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Ingår i: The Journal of China Universities of Posts and Telecommunications. - Amsterdam : Elsevier. - 1005-8885. ; 16:2, s. 63-67
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Tidskriftsartikel (refereegranskat)abstract
- To guarantee the quality of service (QoS) of a wireless network, a new packet scheduling algorithm using cross-layer design technique is proposed in this article. First, the demand of packet scheduling for multimedia transmission in wireless networks and the deficiency of the existing packet scheduling algorithms are analyzed. Then the model of the QoS-guaranteed packet scheduling (QPS) algorithm of high speed downlink packet access (HSDPA) and the cost function of packet transmission are designed. The calculation method of packet delay time for wireless channels is expounded in detail, and complete steps to realize the QPS algorithm are also given. The simulation results show that the QPS algorithm that provides the scheduling sequence of packets with calculated values can effectively improve the performance of delay and throughput.
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