| 1. |
- Sun, Haonan, et al.
(författare)
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Large energy storage density in BiFeO3-BaTiO3-AgNbO3 lead-free relaxor ceramics
- 2020
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Ingår i: Journal of the European Ceramic Society. - : Elsevier. - 0955-2219 .- 1873-619X. ; 40:8, s. 2929-2935
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Tidskriftsartikel (refereegranskat)abstract
- Lead-free (0.70-x)BiFeO3-0.30BaTiO3-xAgNbO3+5‰mol CuO (abbreviated as BF-BT-xAN) ceramics were fabricated using a modified thermal quenching technique. BF-BT-xAN ceramics are of a perovskite structure with morphotropic phase boundary (MPB) and show strong relaxor properties. Remarkably, the high recoverable energy storage density of 2.11 J/cm3 is obtained for BF-BT-xAN with x = 0.14. For the x = 0.14 ceramics, its energy storage efficiency is as high as 84 % at relative low field of 195 kV/cm, together with an outstanding thermal stability in a broad temperature range from 25 °C to 150 °C. In addition, this ceramic maintains superior energy storage performance even after 8 × 104 electrical cycles due to its high densification after doping Ag2O and Nb2O5. The result suggests that lead-free BF-BT-xAN ceramics may be promising candidate for dielectric energy storage application.
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| 2. |
- Li, Xiaoxiao, et al.
(författare)
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Different Vegetation Covers Leading to the Uncertainty and Consistency of ET Estimation : A Case Study Assessment with Extended Triple Collocation
- 2024
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Ingår i: Remote Sensing. - 2072-4292. ; 16:13
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Tidskriftsartikel (refereegranskat)abstract
- Accurate and reliable estimation of actual evapotranspiration (AET) is essential for various hydrological studies, including drought prediction, water resource management, and the analysis of atmospheric–terrestrial carbon exchanges. Gridded AET products offer potential for application in ungauged areas, but their uncertainties may be significant, making it difficult to identify the best products for specific regions. While in situ data directly estimate gridded ET products, their applicability is limited in ungauged areas that require FLUXNET data. This paper employs an Extended Triple Collocation (ETC) method to estimate the uncertainty of Global Land Evaporation Amsterdam Model (GLEAM), Famine Early Warning Systems Network (FLDAS), and Maximum Entropy Production (MEP) AET product without requiring prior information. Subsequently, a merged ET product is generated by combining ET estimates from three original products. Furthermore, the study quantifies the uncertainty of each individual product across different vegetation covers and then compares three original products and the Merged ET with data from 645 in situ sites. The results indicate that GLEAM covers the largest area, accounting for 39.1% based on the correlation coefficient criterion and 39.9% based on the error variation criterion. Meanwhile, FLDAS and MEP exhibit similar performance characteristics. The merged ET derived from the ETC method demonstrates the ability to mitigate uncertainty in ET estimates in North American (NA) and European (EU) regions, as well as tundra, forest, grassland, and shrubland areas. This merged ET could be effectively utilized to reduce uncertainty in AET estimates from multiple products for ungauged areas.
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| 3. |
- Lee, Husileng, et al.
(författare)
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An organic polymer CuPPc-derived copper oxide as a highly efficient electrocatalyst for water oxidation
- 2020
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Ingår i: Chemical Communications. - : ROYAL SOC CHEMISTRY. - 1359-7345 .- 1364-548X. ; 56:26, s. 3797-3800
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report a novel CuPPc (copper polymeric phthalocyanine)/CF (copper foam) nanoflake material, as precatalyst for the generation of an excellent water oxidation catalyst (WOC). Under optimized conditions, the CuPPc-derived Cu oxide affords a current density of 10 mA cm(-2) under an overpotential (eta) of 287 mV and sustains for at least 50 h in 1.0 M KOH. The strategy presented here is favorable to develop the electrocatalysts for water splitting.
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| 4. |
- Lee, Husileng, et al.
(författare)
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Hierarchical CoS2/Ni3S2/CoNiOx nanorods with favorable stability at 1 A cm(-2) for electrocatalytic water oxidation
- 2019
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Ingår i: Chemical Communications. - : ROYAL SOC CHEMISTRY. - 1359-7345 .- 1364-548X. ; 55:11, s. 1564-1567
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we have reported an easily synthesized CoS2/Ni3S2/CoNiOx water oxidation catalyst with excellent catalytic activity and superior durability. The as-prepared catalyst required overpotential (eta) as low as 256 mV to exhibit a current density of 10 mA cm(-2) in 1.0 M KOH. Remarkably, it sustained a current density of 1 A cm(-2) for one week in 30% KOH solution with only 25 mV increment of eta. Thus, it is a hopeful candidate as a highly-effective water oxidation electrode in practical applications.
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| 5. |
- Sethi, V., et al.
(författare)
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Enabling Cryogenic Hydrogen-Based CO 2 -Free Air Transport: Meeting the demands of zero carbon aviation
- 2022
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Ingår i: IEEE Electrification Magazine. - 2325-5889 .- 2325-5897. ; 10:2, s. 69-81
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Flightpath 2050 from the European Union (EU) sets ambitious targets for reducing the emissions from civil aviation that contribute to climate change. Relative to aircraft in service in year 2000, new aircraft in 2050 are to reduce CO2 emissions by 75% and nitrogen oxide (NOx) emissions by 90% per passenger kilometer flown. While significant improvements in asset management and aircraft and propulsion-system efficiency and are foreseen, it is recognized that the Flightpath 2050 targets will not be met with conventional jet fuel. Furthermore, demands are growing for civil aviation to target zero carbon emissions in line with other transportation sectors rather than relying on offsetting to achieve 'net zero.' A more thorough and rapid greening of the industry is seen to be needed to avoid the potential economic and social damage that would follow from constraining air travel. This requires a paradigm shift in propulsion technologies. Two technologies with potential for radical decarbonization are hydrogen and electrification. Hydrogen in some form seems an inevitable solution for a fully sustainable aviation future. It may be used directly as a fuel or combined with carbon from direct air capture of CO2 or other renewable carbon sources, to synthesize drop-in replacement jet fuels for existing aircraft and engines. As a fuel, pure hydrogen can be provided as a compressed gas, but the weight of the storage bottles limits the practical aircraft ranges to just a few times that is achievable with battery power. For longer ranges, the fuel needs to be stored at lower pressures in much lighter tanks in the form of cryogenic liquid hydrogen (LH2).
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| 6. |
- Wang, Xiaoxiao, et al.
(författare)
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Copper Selenide-Derived Copper Oxide Nanoplates as a Durable and Efficient Electrocatalyst for Oxygen Evolution Reaction
- 2020
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Ingår i: Energy Technology. - : Wiley. - 2194-4288 .- 2194-4296. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- Earth-abundant transition metal-based nanomaterials play a signi?cant role in oxygen evolution reaction (OER). Among them, copper has attracted signi?cant attention due to its excellent electrocatalytic activity, low price, and abundance. Herein, a nanostructured copper oxide (CuO-A) is generated in situ from a cuprous selenide (Cu2Se) precursor under oxygen evolution reaction conditions. The as-prepared CuO-A/copper foam (CF) electrode delivers a current density of 10 mA cm(-2) at an overpotential of 297 mV with good stability for over 50 h in 1 m KOH solution, which is superior to most recently reported copper-based water oxidation catalysts. The high catalytic performance of CuO-A is mainly attributed to the improved surface area offered by the morphology reconstruction during the in situ transformation process. As a result, it paves a way to synthesize effective and stable transition metal oxide catalysts via the in situ conversion of transition metal chalcogenides for energy conversion and storage applications.
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| 7. |
- Wu, Xiujuan, et al.
(författare)
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Hollow Carbon@NiCo2O4 Core-Shell Microspheres for Efficient Electrocatalytic Oxygen Evolution
- 2019
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Ingår i: ENERGY TECHNOLOGY. - : Wiley. - 2194-4288 .- 2194-4296. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Earth-abundant transition metal oxides are considered one of the most promising oxygen evolution reaction (OER) catalysts. However, their intrinsically low electrical conductivity inhibits the fast kinetics for OER. To overcome this drawback, hollow carbon@NiCo2O4 core-shell microspheres (C@NiCo2O4 HSs) are synthesized with enhanced electrocatalytic activity and stability toward OER. The prepared C@NiCo2O4/Ni foam delivers a current density of 10 mA cm(-2) at a small overpotential of 268 mV and exhibits a low Tafel slope of 54 mV dec(-1). The enhanced OER performance is attributed to the enlarged specific surface area induced by the combination effect between the 1D nanosheet structure and the 3D hollow microsphere structure, and the improved electrical conductivity is ascribed to the carbon core support.
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| 8. |
- Xie, Haibing, et al.
(författare)
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Decoupling the effects of defects on efficiency and stability through phosphonates in stable halide perovskite solar cells
- 2021
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Ingår i: Joule. - : CELL PRESS. - 2542-4351. ; 5:5, s. 1246-1266
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Tidskriftsartikel (refereegranskat)abstract
- Understanding defects is of paramount importance for the development of stable halide perovskite solar cells (PSCs). However, isolating their distinctive effects on device efficiency and stability is currently a challenge. We report that adding the organic molecule 3-phosphonopropionic acid (H3pp) to the halide perovskite results in unchanged overall optoelectronic performance while having a tremendous effect on device stability. We obtained PSCs with similar to 21% efficiency that retain similar to 100% of the initial efficiency after 1,000 h at the maximum power point under simulated AM1.5G illumination. The strong interaction between the perovskite and the H3pp molecule through two types of hydrogen bonds (H center dot center dot center dot I and O center dot center dot center dot H) leads to shallow point defect passivation that has a significant effect on device stability but not on the non-radiative recombination and device efficiency. We expect that our work will have important implications for the current understanding and advancement of operational PSCs.
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| 9. |
- Yang, Bowen, et al.
(författare)
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Interfacial Passivation Engineering of Perovskite Solar Cells with Fill Factor over 82% and Outstanding Operational Stability on n-i-p Architecture
- 2021
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Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 6:11, s. 3916-3923
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Tidskriftsartikel (refereegranskat)abstract
- Tremendous efforts have been dedicated toward minimizing the open-circuit voltage deficits on perovskite solar cells (PSCs), and the fill factors are still relatively low. This hinders their further application in large scalable modules. Herein, we employ a newly designed ammonium salt, cyclohexylethylammonium iodide (CEAI), for interfacial engineering between the perovskite and hole-transporting layer (HTL), which enhanced the fill factor to 82.6% and consequent PCE of 23.57% on the target device. This can be associated with a reduction of the trap-assisted recombination rate at the 3D perovskite surface, via formation of a 2D perovskite interlayer. Remarkably, the property of the 2D perovskite interlayer along with the cyclohexylethyl group introduced by CEAI treatment also determines a pronounced enhancement in the surface hydrophobicity, leading to an outstanding stability of over 96% remaining efficiency of the passivated devices under maximum power point tracking with one sun illumination under N-2 atmosphere at room temperature after 1500 h.
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| 10. |
- Ye, Xiaoling, et al.
(författare)
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High Performance Self-Powered Photodetectors Based on Graphene Nanoribbons/Al2O3/InGaZnO Heterojunctions
- 2024
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Ingår i: IEEE Photonics Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0655. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- Self-powered photodetectors which operate without external power sources hold immense promise in future photodetection systems. To achieve high-performance self-powered optoelectronic devices, efficient electron-hole pair separation is critical to generate high photocurrents. In this work, we successfully synthesized semiconducting graphene nanoribbons (GNRs) with a direct bandgap of 1.80 eV and employed them to construct a high-performance GNR/Al2O3/IGZO heterostructure photodetector. The built-in electric field in the heterojunctions enables this photodetector to exhibit remarkable performance, showing a responsivity of up to 68 mA/W, a detectivity of 8.34 x 1010 Jones, and rapid response times of 21/20 ms at zero bias. Furthermore, the photodetector features a wide spectral detection range of 405 to 1550 nm. These results highlight the promising potential of GNR/IGZO p-n heterojunction-based self-powered photodetectors in optoelectronic applications.
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| 11. |
- Zheng, Juanrong, et al.
(författare)
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Study on the Strength Development of Cemented Backfill Body from Lead-Zinc Mine Tailings with Sulphide
- 2018
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Ingår i: Advances in Materials Science and Engineering. - : Hindawi Publishing Corporation. - 1687-8434 .- 1687-8442. ; 2018
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Tidskriftsartikel (refereegranskat)abstract
- The unconfined compressive strength (UCS) development of cemented backfill materials for lead-zinc mine tailings with sulphide was studied. The results showed that the UCS of the cemented backfill body with ordinary Portland cement (OPC) as binder decreased in the later curing days, regardless of particle size. Under the same conditions, the higher the OPC content, the higher the UCS of the cemented backfill body, and the UCS of the cemented backfill body began to decrease at the longer curing days. Under the same conditions, the finer the tailings, the lower the UCS of the cemented backfill body at each age, and the UCS of the cemented backfill body began to decrease at the earlier curing age. X-ray diffraction analysis (XRD) showed that the reduction of the UCS of the cemented backfill body was related to the formation of an expansive substance (expansive gypsum) in the cemented backfill body, which led to the cracking of the test sample. In the cemented backfill materials of coarse tailings of lead-zinc mine, the composite binder formed by OPC and calcined kaolin (CK) containing metakaolin was used; the amount of calcium hydroxide, the hydration product of cement, was reduced or eliminated due to the pozzolanic reaction of metakaolin; and the amount of expansive gypsum was reduced or eliminated, so the UCS of the cemented backfill body increased within 360 days of curing.
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