| 1. |
- Ablikim, M., et al.
(författare)
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Measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda mu(+)nu(mu)
- 2017
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Ingår i: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 767, s. 42-47
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Tidskriftsartikel (refereegranskat)abstract
- We report the first measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda mu(+)nu(mu).This measurement is based on a sample of e+e(-) annihilation data produced at a center-of-mass energy root s = 4.6 GeV, collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pb(-1). The branching fraction is determined to be B( Lambda(+)(c) -> Lambda mu(+)nu(mu)) = (3.49 +/- 0.46( stat) +/- 0.27( syst))%. In addition, we calculate the ratio B( Lambda(+)(c) -> Lambda mu(+)nu(mu))/B(Lambda(+)(c) -> Lambda e(+)nu(e) to be 0.96 +/- 0.16( stat) +/- 0.04( syst).
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| 2. |
- Ablikim, M., et al.
(författare)
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Measurement of branching fractions for psi(3686) -> gamma eta ', gamma eta, and gamma pi(0)
- 2017
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 96:5
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 448 x 10(6) psi(3686) events collected with the BESIII detector operating at the BEPCII storage ring, the decays psi(3686) -> gamma eta and psi(3686) -> gamma pi(0) are observed with a statistical significance of 7.3 sigma and 6.7 sigma, respectively. The branching fractions are measured to be B(psi(3686) -> gamma eta) = (0.85 +/- 0.18 +/- 0.05) x 10(-6) and B(psi(3686) ->gamma pi(0)) = (0.95 +/- 0.16 +/- 0.05) x 10(-6). In addition, we measure the branching fraction of psi(3686) -> gamma eta' to be B(psi(3686) -> gamma eta') = (125.1 +/- 2.2 +/- 6.2)x10(-6), which represents an improvement of precision over previous results.
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| 3. |
- Bagheri, Niusha, et al.
(författare)
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Change in the emission saturation and kinetics of upconversion nanoparticles under different light irradiations
- 2019
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Ingår i: Optical materials (Amsterdam). - : Elsevier. - 0925-3467 .- 1873-1252. ; 97
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Tidskriftsartikel (refereegranskat)abstract
- Nd3+-sensitized upconversion nanoparticles (UCNPs) can be excited by both 980 and 808 nm light, which is regarded as a particularly advantageous property of these particles. In this work, we demonstrate that the nanoparticles can exhibit significantly different response when excited at these two excitation wavelengths, showing dependence on the intensity of the excitation light and the way it is distributed in time. Specifically, with 808 nm excitation saturation in the emitted luminescence is more readily reached with increasing excitation intensities than upon 980 nm excitation. This is accompanied by delayed upconversion luminescence (UCL) kinetics and weaker UCL intensities. The different luminescence response at 808 and 980 nm excitation reported in this work is relevant in a manifold of applications using UCNPs as labels and sensors. This could also open new possibilities for multi-wavelength excitable UCNPs for upconversion color display and in laser-scanning microscopy providing selective readouts and sub-sectioning of samples.
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| 4. |
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| 5. |
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| 6. |
- Qi, D., et al.
(författare)
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Increase in acidifying water in the western Arctic Ocean
- 2017
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- The up(t)ake of anthropogenic CO2 by the ocean decreases seawater pH and carbonate mineral aragonite saturation state (Omega(arag)), a process known as Ocean Acidification (OA). This can be detrimental to marine organisms and ecosystems(1,2). The Arctic Ocean is particularly sensitive to climate change(3) and aragonite is expected to become undersaturated (Omega(arag) < 1) there sooner than in other oceans(4). However, the extent and expansion rate of OA in this region are still unknown. Here we show that, between the 1990s and 2010, low Omega(arag) waters have expanded northwards at least 5 degrees, to 85 degrees N, and deepened 100 m, to 250m depth. Data from trans-western Arctic Ocean cruises show that Omega(arag) < 1 water has increased in the upper 250m from 5% to 31% of the total area north of 70 ffi N. Tracer data and model simulations suggest that increased Pacific Winter Water transport, driven by an anomalous circulation pattern and sea-ice retreat, is primarily responsible for the expansion, although local carbon recycling and anthropogenic CO2 uptake have also contributed. These results indicate more rapid acidification is occurring in the Arctic Ocean than the Pacific and Atlantic oceans(5-8), with the western Arctic Ocean the first open-ocean region with large-scale expansion of 'acidified' water directly observed in the upper water column.
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| 7. |
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| 8. |
- Zhan, M., et al.
(författare)
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Understanding readers : Conducting sentiment analysis of instagram captions
- 2018
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Ingår i: PROCEEDINGS OF 2018 THE 2ND INTERNATIONAL CONFERENCE ON COMPUTER SCIENCE AND ARTIFICIAL INTELLIGENCE (CSAI 2018) / 2018 THE 10TH INTERNATIONAL CONFERENCE ON INFORMATION AND MULTIMEDIA TECHNOLOGY (ICIMT 2018). - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450366069 ; , s. 33-40
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Konferensbidrag (refereegranskat)abstract
- The advent of media transition highlights the importance of user-generated content on social media. Amongst the methods of analysis of user-generated content, sentiment analysis is widely used. Nevertheless, few studies use sentiment analysis to investigate user-generated content on Instagram in the context of public libraries. Therefore, this study aims to fill this research gap by conducting sentiment analysis of two million captions on Instagram. Supervised machine learning algorithms were employed to create the classifier. Three opinion polarities and six emotions were ultimately identified via these captions. These polarities provide new insights for understanding readers, thus helping libraries to deliver better services.
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| 9. |
- Zhan, Q., et al.
(författare)
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Tens of thousands-fold upconversion luminescence enhancement induced by a single gold nanorod
- 2015
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Ingår i: Laser & Photonics reviews. - : Wiley-VCH Verlagsgesellschaft. - 1863-8880 .- 1863-8899. ; 9:5, s. 479-487
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Tidskriftsartikel (refereegranskat)abstract
- Upconversion nanoparticles (UCNPs) have gained increasing attention for their wide applications in bioimaging, displays and photovoltaics. However, low efficiency has been an ongoing challenge for further developments. In this work, it is proposed that the ultrasmall size of UCNPs is essential for achieving large enhancement factors and experimentally demonstrated with 4-nm UCNPs. A strategy of plasmonic dual resonance is proposed in which two distinct localized surface plasmon resonance (LSPR) peaks of gold nanorods (GNRs) were designed to perfectly match both the excitation and emission light wavelength of UCNPs. Combining the excitation enhancement and Purcell effect, a huge enhancement factor of tens of thousands-fold is stochastically demonstrated for single UCNPs in solution. The largest overall enhancement region is close to the end of a GNR but not in its central part. The excitation enhancement (up to three orders of magnitude) and the emission enhancement (larger than one order of magnitude) induced by the Purcell effect are experimentally demonstrated separately. This study provides insight into how to achieve a very large upconversion enhancement factor with surface plasmons and will catalyze development of UCNPs' extensive applications.
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