| 1. |
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| 2. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Jian, Jingxin, et al.
(författare)
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A nanostructured NiO/cubic SiC p-n heterojunction photoanode for enhanced solar water splitting
- 2019
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 7:9, s. 4721-4728
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectrochemical (PEC) water-splitting offers a promising method to convert the intermittent solar energy into renewable and storable chemical energy. However, the most studied semiconductors generally exhibit a poor PEC performance including low photocurrent, small photovoltage, and/or large onset potential. In this work, we demonstrate a significant enhancement of photovoltage and photocurrent together with a substantial decrease of onset potential by introducing electrocatalytic and p-type NiO nanoclusters on an n-type cubic silicon carbide (3C-SiC) photoanode. Under AM1.5G 100 mW cm(-2) illumination, the NiO-coated 3C-SiC photoanode exhibits a photocurrent density of 1.01 mA cm(-2) at 0.55 V versus reversible hydrogen electrode (V-RHE), a very low onset potential of 0.20 V-RHE and a high fill factor of 57% for PEC water splitting. Moreover, the 3C-SiC/NiO photoanode shows a high photovoltage of 1.0 V, which is the highest value among reported photovoltages. The faradaic efficiency measurements demonstrate that NiO also protects the 3C-SiC surface against photo-corrosion. The impedance measurements evidence that the 3C-SiC/NiO photoanode facilitates the charge transfer for water oxidation. The valence-band position measurements confirm the formation of the 3C-SiC/NiO p-n heterojunction, which promotes the separation of the photogenerated carriers and reduces carrier recombination, thus resulting in enhanced solar water-splitting.
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| 5. |
- Jian, Jingxin, et al.
(författare)
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Cubic SiC Photoanode Coupling with Ni:FeOOH Oxygen-Evolution Cocatalyst for Sustainable Photoelectrochemical Water Oxidation
- 2020
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Ingår i: Solar RRL. - : WILEY-V C H VERLAG GMBH. - 2367-198X. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- As an efficient water oxidation cocatalyst, the Earth-abundant nickel-iron oxyhydroxide (Ni:FeOOH) is introduced to coat on the cubic silicon carbide (3C-SiC) photoanode surface for improving the photoelectrochemical (PEC) water oxidation performance. The FeOOH is prepared on the 3C-SiC photoanode surface by hydrothermal deposition, followed by a photoassisted electrodeposition of NiOOH. It is shown that the Ni:FeOOH layer is composed of the beta-FeOOH nanorods with a conformal coating of the amorphous NiOOH. Under AM1.5G 100 mW cm(-2) illumination, the 3C-SiC/Ni:FeOOH photoanode exhibits a very low onset potential of 0.2 V versus reversible hydrogen electrode (V-RHE) and a high photocurrent density of 1.15 mA cm(-2) at 1.23 V-RHE, distinctly outperforming the 3C-SiC and the 3C-SiC/FeOOH counterparts. Open-circuit potential and impedance spectroscopy results demonstrate that the nanostructured Ni:FeOOH layer on the 3C-SiC surface increases the photovoltage and promotes the charge transfer toward the electrolyte, thus significantly improving the PEC water-splitting performance. These results provide new insights for the development of photoanodes toward efficient solar-fuel generation.
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| 6. |
- Jiang, Xiaoqing, et al.
(författare)
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Efficient perovskite solar cells employing a solution-processable copper phthalocyanine as a hole-transporting material
- 2017
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Ingår i: Science China Chemistry. - : Science in China Press. - 1674-7291 .- 1869-1870. ; 60:3, s. 423-430
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Tidskriftsartikel (refereegranskat)abstract
- The development of alternative low-cost and high-performing hole-transporting materials (HTMs) is of great significance for the potential large-scale application of perovskite solar cells (PSCs) in the future. Here, a facilely synthesized solution-processable copper tetra-(2,4-dimethyl-3-pentoxy) phthalocyanine (CuPc-DMP) via only two simple steps, has been incorporated as a hole-transporting material (HTM) in mesoscopic perovskite solar cells (PSCs). The optimized devices based on such a HTM afford a very competitive power conversion efficiency (PCE) of up to 17.1% measured at 100 mW cm(-2) AM 1.5G irradiation, which is on par with that of the well-known 2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) (16.7%) under equivalent conditions. This is, to the best of our knowledge, the highest value reported so far for metal organic complex-based HTMs in PSCs. The advantages of this HTM observed, such as facile synthetic procedure, superior hole transport characteristic, high photovoltaic performance together with the feasibility of tailoring the molecular structure would make solution-processable copper phthalocyanines as a class of promising HTM that can be further explored in PSCs. The present finding highlights the potential application of solution processed metal organic complexes as HTMs for cost-effective and high-performing PSCs.
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| 7. |
- Jiang, Xiaoqing, et al.
(författare)
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High-Performance Regular Perovskite Solar Cells Employing Low-Cost Poly(ethylenedioxythiophene) as a Hole-Transporting Material
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we successfully applied a facile in-situ solid-state synthesis of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as a HTM, directly on top of the perovskite layer, in conventional mesoscopic perovskite solar cells (PSCs) (n-i-p structure). The fabrication of the PEDOT film only involved a very simple in-situ solid-state polymerisation step from a monomer 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) made from a commercially available and cheap starting material. The ultraviolet photoelectron spectroscopy (UPS) demonstrated that the as-prepared PEDOT film possesses the highest occupied molecular orbital (HOMO) energy level of -5.5 eV, which facilitates an effective hole extraction from the perovskite absorber as confirmed by the photoluminescence measurements. Optimised PSC devices employing this polymeric HTM in combination with a low-cost vacuum-free carbon cathode (replacing the gold), show an excellent power conversion efficiency (PCE) of 17.0% measured at 100 mW cm(-2) illumination (AM 1.5G), with an open-circuit voltage (V-oc) of 1.05 V, a short-circuit current density (J(sc)) of 23.5 mA/cm(2) and a fill factor (FF) of 0.69, respectively. The present finding highlights the potential application of PEDOT made from solid-state polymerisation as a HTM for cost-effective and highly efficient PSCs.
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| 8. |
- Jiang, Yuchen, et al.
(författare)
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Early-age performance of lag screw shear connections for glulam-lightweight concrete composite beams
- 2017
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Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618. ; 151, s. 36-42
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Tidskriftsartikel (refereegranskat)abstract
- Mechanical behavior of the shear connections has a significant influence on both the load-carrying capacity and the bending stiffness of timber-concrete composite (TCC) beams. All the studies reported so far have concentrated on the performance of TCC connections in mature concrete. The performance of shear connections for TCC beams at early concrete ages, however, has not been investigated yet. This information is essential to evaluate the structural behavior of TCC floors or bridges during construction. In this paper, a total of 18 push-out tests with concrete ages ranging from 12 h to 28 days are performed, to investigate the early-age performance of lag screw shear connections in the lightweight concrete. Development of concrete strength with time is also analyzed. At the concrete ages shorter than 7 days, both the stiffness and strength of the screw connectors increase evidently with time, which follows the same growth trend with the concrete strength. After a 7-day cure, screw shear connections reach almost 100% of both the 28-day serviceability slip modulus and shear strength. Material properties of the glulam and the screw fastener are decisive in the shear performance of connections when the concrete hardens to some degree. Based on the experimental results, the accuracy of the design methods proposed in Eurocode 5 is evaluated. In addition, by non-linear regression of the experiment data, expressions to predict the development of load-carrying capacity and serviceability slip modulus for screw shear connections before 28 days are established.
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| 9. |
- Li, Hao, et al.
(författare)
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Atomic-Scale Tuning of Graphene/Cubic SiC Schottky Junction for Stable Low-Bias Photoelectrochemical Solar-to-Fuel Conversion
- 2020
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 14:4, s. 4905-4915
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Tidskriftsartikel (refereegranskat)abstract
- Engineering tunable graphene-semiconductor interfaces while simultaneously preserving the superior properties of graphene is critical to graphene-based devices for electronic, optoelectronic, biomedical, and photoelectrochemical applications. Here, we demonstrate this challenge can be surmounted by constructing an interesting atomic Schottky junction via epitaxial growth of high-quality and uniform graphene on cubic SiC (3C-SiC). By tailoring the graphene layers, the junction structure described herein exhibits an atomic-scale tunable Schottky junction with an inherent built-in electric field, making it a perfect prototype to systematically comprehend interfacial electronic properties and transport mechanisms. As a proof-of-concept study, the atomic-scale-tuned Schottky junction is demonstrated to promote both the separation and transport of charge carriers in a typical photoelectrochemical system for solar-to-fuel conversion under low bias. Simultaneously, the as-grown monolayer graphene with an extremely high conductivity protects the surface of 3C-SiC from photocorrosion and energetically delivers charge carriers to the loaded cocatalyst, achieving a synergetic enhancement of the catalytic stability and efficiency.
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| 10. |
- Li, Hao, et al.
(författare)
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Atomically manipulated proton transfer energizes water oxidation on silicon carbide photoanodes
- 2018
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 6:47, s. 24358-24366
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Tidskriftsartikel (refereegranskat)abstract
- Surmounting the sluggish water oxidation kinetics beyond the hole-dominated thermodynamic effect is a topic of great scientific interest to establish fully renewable hydrogen technology from solar-powered water splitting. Herein, we demonstrate that the bottleneck of photoelectrochemical water oxidation can be overcome via atomic manipulation of proton transfer on the polar surfaces of silicon carbide (SiC) photoanodes. On the typical carbon-face SiC, where proton-coupled electron transfer governed the interfacial hole transfer for water oxidation, substantial energy loss was inevitable due to the highly activated proton-transfer steps. Via preferentially exposing the silicon-face, we enabled surface-catalyzed barrierless O-H breaking with a facile proton exchange and migration character. This mechanistically shifted the rate limiting step of water oxidation from sluggish proton-coupled electron transfer to a more energy-favorable electron transfer. The proof-of-concept study introduced here may open up new possibilities to design sophisticated photoelectrodes for an unbiased solar water splitting cell via surface engineering.
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