| 1. |
- Li, Bin, et al.
(författare)
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Phase Transitions of Oppositely Charged Colloidal Particles Driven by Alternating Current Electric Field
- 2021
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 15:2, s. 2363-2373
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Tidskriftsartikel (refereegranskat)abstract
- We study systems containing oppositely charged colloidal particles under applied alternating current electric fields (AC fields) using overdamped Langevin dynamics simulations in three dimensions. We obtain jammed bands perpendicular to the field direction under intermediate frequencies and lanes parallel with the field under low frequencies. These structures also depend upon the particle charges. The pathway for generating jammed bands follows a stepwise mechanism, and intermediate bands are observed during lane formation in some systems. We investigate the component of the pressure tensors in the direction parallel to the field and observe that the jammed to lane transition occurs at a critical value for this pressure. We also find that the stable steady states appear to satisfy the principle of maximum entropy production. Our results may help to improve the understand of the underlying mechanisms for these types of dynamic phase transitions and the subsequent cooperative assemblies of colloidal particles under such non-equilibrium conditions.
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| 2. |
- Liu, Huanji, et al.
(författare)
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3D Lattice-Matching Layered Hydroxide Heterostructure with Improved Interfacial Charge Transfer and Ion Diffusion for High Energy Density Supercapacitor
- 2021
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Ingår i: Advanced Materials Interfaces. - : John Wiley & Sons. - 2196-7350. ; 8:14, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- The electrochemical charge storage mostly relies on the electrical properties of complex interfaces and electrode materials as well as the dynamic ions diffusion in the electrolytes. Nickel-cobalt layered double hydroxides (LDHs) with tunable chemical composition are promising for electrochemical supercapacitors, where the theoretical performance could be up to 3000 F g(-1). However, the experimental performances of NiCo-LDHs are still limited by low charge transfer rate and slow dynamic ions diffusion. Here, a 3D lattice matching Ni0.85Co0.15(OH)(2)@alpha-Co(OH)(2) heterostructure is epitaxially grown. The experimental results and theoretical calculation confirm that such a 3D heterostructure could improve charge transfer abilities and accelerated ions diffusion. The specific capacitance of 2480 F g(-1) and retained 71% of the initial capacitance at high current density of 30 A g(-1) have been achieved by optimal Co(OH)(2) amount of 20 mg (NCC-20). Asymmetric button devices and soft-pack devices have been demonstrated with exceptional energy densities of 69.2 and 65.7 Wh kg(-1) at power densities of 0.79 and 0.78 kW kg(-1), and maintained 88% and 80% initial capacitance under 10 000 cycles, respectively. The general design principles clearly demonstrate the importance of electrochemical interface and dynamic process, paving the way to push forward the application capability of electrochemical devices.
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| 3. |
- Pinto, Dalila, et al.
(författare)
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Comprehensive assessment of array-based platforms and calling algorithms for detection of copy number variants
- 2011
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Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 29:6, s. 512-521
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Tidskriftsartikel (refereegranskat)abstract
- We have systematically compared copy number variant (CNV) detection on eleven microarrays to evaluate data quality and CNV calling, reproducibility, concordance across array platforms and laboratory sites, breakpoint accuracy and analysis tool variability. Different analytic tools applied to the same raw data typically yield CNV calls with <50% concordance. Moreover, reproducibility in replicate experiments is <70% for most platforms. Nevertheless, these findings should not preclude detection of large CNVs for clinical diagnostic purposes because large CNVs with poor reproducibility are found primarily in complex genomic regions and would typically be removed by standard clinical data curation. The striking differences between CNV calls from different platforms and analytic tools highlight the importance of careful assessment of experimental design in discovery and association studies and of strict data curation and filtering in diagnostics. The CNV resource presented here allows independent data evaluation and provides a means to benchmark new algorithms.
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| 4. |
- Zheng, Yan, et al.
(författare)
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Precursors and Pathways Leading to Enhanced Secondary Organic Aerosol Formation during Severe Haze Episodes
- 2021
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:23, s. 15680-15693
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Tidskriftsartikel (refereegranskat)abstract
- Molecular analyses help to investigate the key precursors and chemical processes of secondary organic aerosol (SOA) formation. We obtained the sources and molecular compositions of organic aerosol in PM2.5 in winter in Beijing by online and offline mass spectrometer measurements. Photochemical and aqueous processing were both involved in producing SOA during the haze events. Aromatics, isoprene, long-chain alkanes or alkenes, and carbonyls such as glyoxal and methylglyoxal were all important precursors. The enhanced SOA formation during the severe haze event was predominantly contributed by aqueous processing that was promoted by elevated amounts of aerosol water for which multifunctional organic nitrates contributed the most followed by organic compounds having four oxygen atoms in their formulae. The latter included dicarboxylic acids and various oxidation products from isoprene and aromatics as well as products or oligomers from methylglyoxal aqueous uptake. Nitrated phenols, organosulfates, and methanesulfonic acid were also important SOA products but their contributions to the elevated SOA mass during the severe haze event were minor. Our results highlight the importance of reducing nitrogen oxides and nitrate for future SOA control. Additionally, the formation of highly oxygenated long-chain molecules with a low degree of unsaturation in polluted urban environments requires further research.
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