| 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. |
- Deng, Xiaolong, et al.
(författare)
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Anisotropy-mediated reentrant localization
- 2022
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Ingår i: SciPost Physics. - : Stichting SciPost. - 2542-4653. ; 13:5
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Tidskriftsartikel (refereegranskat)abstract
- We consider a 2d dipolar system, d = 2, with the generalized dipole-dipole interaction similar to r(-a), and the power a controlled experimentally in trapped-ion or Rydberg-atom systems via their interaction with cavity modes. We focus on the dilute dipolar excitation case when the problem can be effectively considered as single-particle with the interaction providing long-range dipolar-like hopping. We show that the spatially homogeneous tilt beta of the dipoles giving rise to the anisotropic dipole exchange leads to the non-trivial reentrant localization beyond the locator expansion, a < d, unlike the models with random dipole orientation. The Anderson transitions are found to occur at the finite values of the tilt parameter beta = a, 0 < a < d, and beta = a =(a d =2), d =2 < a < d, showing the robustness of the localization at small and large anisotropy values. Both exact analytical methods and extensive numerical calculations show power-law localized eigenstates in the bulk of the spectrum, obeying recently discovered duality a <-> 2d -a of their spatial decay rate, on the localized side of the transition, a > a(AT). This localization emerges due to the presence of the ergodic extended states at either spectral edge, which constitute a zero fraction of states in the thermodynamic limit, decaying though extremely slowly with the system size.
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| 3. |
- Deng, Xiaolong, et al.
(författare)
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Superdiffusion in a random two-dimensional system with time-reversal symmetry and long-range hopping
- 2024
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Ingår i: Physical Review B. - : American Physical Society (APS). - 2469-9950 .- 2469-9969. ; 109:17
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Tidskriftsartikel (refereegranskat)abstract
- Although it is recognized that Anderson localization takes place for all states at a dimension d less than or equal to 2, while delocalization is expected for hopping V(r) decreasing with the distance slower or as r-d, the localization problem in the crossover regime for the dimension d=2 and hopping V(r)â r-2 is not resolved yet. Following earlier suggestions we show that for the hopping determined by two-dimensional anisotropic dipole-dipole interactions in the presence of time-reversal symmetry there exist two distinguishable phases at weak and strong disorder. The first phase is characterized by ergodic dynamics and superdiffusive transport, while the second phase is characterized by diffusive transport and delocalized eigenstates with fractal dimension less than 2. The transition between phases is resolved analytically using the extension of scaling theory of localization and verified numerically using an exact numerical diagonalization.
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| 4. |
- Liu, Daosheng, et al.
(författare)
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Investigation on heating aging mechanism of cellulose paper for oil-immersed transformer main insulation
- 2019
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Ingår i: Proceedings - IEEE International Conference on Dielectric Liquids. - 2153-3733 .- 2153-3725. ; 2019-June:June
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Konferensbidrag (refereegranskat)abstract
- Power transformer plays a vital role in maintaining reliable and efficient electricity supply. However, in service is increasing and growing older, much and much attention has been paid on their aging condition and life assessment than ever. The aging and degradation of transformer insulation will determine the life-time of its operation. The intensities of these depend on mechanical, thermal and environmental stresses that act on the insulations. Due to the temperature rise, the lifetime of insulation material will be shortened. The accelerated thermal aging method is often adopted to do some evaluation on the oil-paper insulation materials under different temperature for the thermal lifetime model. According to existing aging test, both insulation paper and mineral oil were aged at the same temperature. In this paper, the thermal aging experiments were implemented on the transformer main insulation model made with modified and unmodified insulation paper. The accelerated thermal aging tests were finished, and the superior electric characteristics of the nano-TiO2 and cellulose composition insulation were validated.
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| 5. |
- Sun, Yan, et al.
(författare)
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Metal-free Se-based tetra-doped carbon catalyst for high-selective electro-reduction of CO2 into CO
- 2023
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Ingår i: Journal of Environmental Chemical Engineering. - 2213-3437. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- In electrocatalytic CO2 reduction reaction (CO2RR), metal-free Se-based multi-doping carbon has become a new focus. In this paper, a series of metal-free Se, B, P, N doped carbon-based catalysts (Se-BP-N-C) were prepared by a simple and scalable pyrolysis method. The electrocatalytic CO2 reduction results show that, the main product on Se-BP-N-C catalyst is CO, and there are no other by-products except H2. Specifically, the optimal one prepared at 1050 °C (named Se-BP-N-C (1050)), can selectively reduce CO2 into CO with Faradaic efficiency (FE) up to 96.2% (at − 0.5 V), and maintains long-term stability after continuous electrolysis for 10 h in a flow cell (current density remained 82.7%). This study would provide a good reference for designing advanced efficient metal-free catalysts in electrocatalysis.
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