| 1. |
- 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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| 2. |
- An, Yiming, et al.
(författare)
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Temporal changes on soil conservation services in large basins across the world
- 2022
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Ingår i: Catena (Cremlingen. Print). - : Elsevier BV. - 0341-8162 .- 1872-6887. ; 209
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Tidskriftsartikel (refereegranskat)abstract
- Soil erosion is one of the main drivers of land degradation across the world, thus soil conservation service has received increasing attention. Limited studies have focused on it, hence this study investigates spatial and temporal patterns on soil conservation service in four large representative basins globally (i.e., Amazon, Mississippi, Yangtze, and Yellow River Basins), between 2001 and 2018. Annual soil conservation service and soil erosion rate are estimated under RUSLE framework, and temporal trends are analyzed using Mann-Kendall test. Additionally, impacts of soil erosion factors on spatial distribution of soil conservation service are assessed through fitting stepwise regressions annually and calculating the factors' contributions. Furthermore, driving factors of temporal changes are identified as climate or land cover dominated, and combined effect of both, according to Z scores from Mann-Kendall test for soil conservation service, R and C factors. Results show the Yangtze River Basin produces the highest average annual erosion rate (mean values of 133.28 Mg ha(-1) yr(-1) in 2001 and 143.21 Mg ha(-1) yr(-1) in 2018) and average soil conservation service (mean values of 2663.57 Mg ha(-1) yr(-1) in 2001 and 3126.43 Mg ha(-1) yr(-1) in 2018). Amazon River Basin yields the lowest average annual soil erosion rate (15.96 Mg ha(-1) yr(-1) in 2001 and 21.30 Mg ha(-1) yr(-1) in 2018), whereas the Mississippi River Basin produces the lowest average soil conservation service (388.48 Mg ha(-1) yr(-1) in 2001 and 730.70 Mg ha(-1) yr(-1) in 2018). Over the study period, soil conservation service shows an increasing trend in the Yangtze and Yellow River Basins, with average changing rates of 27.23 Mg ha(-1) yr(-1) and 16.60 Mg ha(-1) yr(-1), respectively. Increasing soil conservation service is mainly driven by climate change (i.e., rainfall) and the combined effect of climate and land cover changes, but terrain conditions are the main spatial drivers.
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| 3. |
- Ding, Haoming, et al.
(författare)
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Progress in Structural Tailoring and Properties of Ternary Layered Ceramics
- 2023
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Ingår i: Journal of Inorganic Materials. - : SCIENCE PRESS. - 1000-324X. ; 38:8, s. 845-884
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Forskningsöversikt (refereegranskat)abstract
- MAX/MAB phases are a series of non-van der Waals ternary layered ceramic materials with a hexagonal structure, rich in elemental composition and crystal structure, and embody physical properties of both ceramics and metals. They exhibit great potential for applications in extreme environments such as high temperature, strong corrosion, and irradiation. In recent years, two-dimensional (2D) materials derived from the MAX/MAB phase (MXene and MBene) have attracted enormous interest in the fields of materials physics and materials chemistry and become a new 2D van der Waals material after graphene and transition metal dichalcogenides. Therefore, structural modulation of MAX/MAB phase materials is essential for understanding the intrinsic properties of this broad class of layered ceramics and for investigating the functional properties of their derived structures. In this paper, we summarize new developments in MAX/MAB phases in recent years in terms of structural modulation, theoretical calculation, and fundamental application research and provide an outlook on the key challenges and prospects for the future development of these layered materials.
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| 4. |
- Gao, Lingfeng, et al.
(författare)
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Emerging applications of MXenes for photodetection : Recent advances and future challenges
- 2022
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Ingår i: Materials Today. - : Elsevier. - 1369-7021 .- 1873-4103. ; 61, s. 169-190
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Tidskriftsartikel (refereegranskat)abstract
- The development and applications of transition metal carbides, nitrides and carbonitrides, commonly denoted as MXenes, have during the last few years rapidly expanded in various technological fields owing to their unique and controllable properties. These materials exhibit competing performance comparing with traditional materials and have created numerous opportunities for technology markets. Taking the advantage of excellent optoelectronic features, MXenes have been utilized for the construction of photodetectors with various structures and unique functionalities. While the appli-cation of MXenes in this area can be traced back to 2016, we have during the recent three years witnessed a dramatic development of MXene-based photodetectors, calling for a timely review to guideline their future direction. In this work, synthetic strategies of pristine MXenes are briefly introduced and their properties are discussed focusing on the optoelectronic aspects that are fundamental for the photoelectric conversion. Recent advances of MXene-based photodetectors are comprehensively summarized based on different types of MXenes and innovative designs of device construction. Finally, we provide perspectives for future challenges and opportunities of MXene-based photodetectors, which may enlighten their further development.
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| 5. |
- Xia, Yangyang, et al.
(författare)
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Prediction of bending strength of glass fiber reinforced methacrylate-based pipeline UV-CIPP rehabilitation materials based on machine learning
- 2023
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Ingår i: Tunnelling and Underground Space Technology. - : Elsevier. - 0886-7798 .- 1878-4364. ; 140
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Tidskriftsartikel (refereegranskat)abstract
- Ultraviolet cured-in-place-pipe (UV-CIPP) materials are commonly used in trenchless pipeline rehabilitation. Their bending strength is a crucial indicator to evaluate the curing quality. Studies show that this indicator is affected by multiple factors, including the curing time, UV lamp curing power, curing distance, and material thickness. Laboratory experiments have limitations in analyzing the effect of multiple factors on the bending strength of UV-CIPP materials and quantitatively predicting the optimum curing parameters. Aiming at resolving these shortcomings, resolve machine learning techniques were applied to predict the bending strength. In this regard, the surface curing reaction temperature monitoring data and three-point bending data of 30 groups of UV-CIPP material under the influence of different curing parameters were used as a dataset to predict the bending strength of UV-CIPP material. The results show that the influence degree of each factor on the bending strength of the UV-CIPP material, from high to low, is as follows: UV lamp power (−0.439), the temperature at the illuminated side (−0.392), curing time (−0.323), the temperature at the back side (−0.233), curing distance (0.143) and material thickness (−0.140). The best penalty parameter c (44.435) and width g (0.072) of the kernel function in the support vector machine (SVM) model were obtained using the genetic algorithm (GA) optimization, and the results were compared with the grey wolf optimizer (GWO) and particle swarm optimization (PSO). The performed analyses revealed that the developed GA-SVM model exhibits the best prediction results compared to other machine learning algorithms. The optimum bending strength of the UV-CIPP material used in this test is 294.77 MPa, which corresponds to the curing time, UV lamp power, curing distance, material thickness, light side temperature, and back side temperature of 7.59 min, 157.33 mW/cm2, 189.99 mm, 4.38 mm, 79.49 °C, and 76.59 °C, respectively.
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| 6. |
- Zhao, Yiming, et al.
(författare)
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Fabrication of lead telluride quantum dots and their application in photoelectrochemical-type photodetectors
- 2023
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Ingår i: Nano Today. - : ELSEVIER SCI LTD. - 1748-0132 .- 1878-044X. ; 52
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Tidskriftsartikel (refereegranskat)abstract
- IV-VI semiconductors have been extensively applied in photo-electrochemical (PEC)-type photodetectors. However, electrolytes with relatively high concentrations have been addressed which could induce electro-chemical reactions during the measurement and result in a performance decrement. In this work, lead telluride quantum dots (PbTe QDs) with uniform size distribution are fabricated for PEC-type photodetectors and their performance is systematically investigated in electrolytes with concentrations as low as 10-4 mol/L. As revealed, the PbTe QD-based photodetectors show apparent photo-response with excellent stability in 1000 cycles (decrement of 0.018 % per cycle). In addition, the as-fabricated photodetectors show a broadband response to light in a region of 350-700 nm. These results are well supported by density functional theory calculations based on structural features and electronic and optical properties. Hence, we envisage that this work paves the way to fabricate high-performance photodetectors in relatively low-concentration electrolytes, which also can extend their applications to other optoelectronic devices.
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