| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Lind, Lars, et al.
(författare)
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Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)
- 2021
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Ingår i: eLife. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.
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| 3. |
- Aktas, Özge, 1987-, et al.
(författare)
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First observation of γ-ray transitions in 111Mo
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X.
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in the extremely neutron-rich nuclei 109Mo and 111Mo have been studied following nucleon knock-out reactions. Seven $\gamma$-ray transitions, some of them in prompt mutual coincidence, have been identified for the first time in 11Mo using the DALI2 and MINOS detector systems at the BigRIPS and ZeroDegree electromagnetic fragments separator at the RIBF, RIKEN, Japan. Total Routhian surface (TRS) and Particle- Plus Rotor calculations have been performed to investigate the predicted shape coexistence and its effect on the structure of nuclei in this region of the nuclear chart. Following the results of the calculations, theoretical level schemes are proposed for positive and negative parity states and compared with the experimental findings.
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| 4. |
- Aktas, Özge, et al.
(författare)
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Single-particle structures in 85,87Ge
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X.
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Tidskriftsartikel (refereegranskat)abstract
- Gamma-ray transitions have been identified for the first time in the extremely neutron-rich (N =Z + 25) nucleus 87 Ge following nucleon knockout reactions studied at the RIBF, RIKEN, Japan.New γ-ray transitions from excited states in 85 Ge were also observed and placed in a tentative levelscheme. The exclusive parallel momentum distribution was measured for the 1/2 + state for theneutron knockout reaction leading to 85 Ge which is compared with calculated distorted wave impulseapproximation (DWIA) distributions. The 85,87 Ge results are compared with large-scale shell-modelcalculations and potential energy surface calculations based on the total Routhian surface formalism.
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| 5. |
- Browne, F., et al.
(författare)
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Pairing Forces Govern Population of Doubly Magic Ca-54 from Direct Reactions
- 2021
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Ingår i: Physical Review Letters. - : American Physical Society (APS). - 0031-9007 .- 1079-7114. ; 126:25
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Tidskriftsartikel (refereegranskat)abstract
- Direct proton-knockout reactions of Sc-55 at similar to 220 MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of Ca-54 were investigated through -ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological intemucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the Sc-55 ground state with states in Ca-54. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of Sc-55, valence proton removals populated predominantly the ground state of Ca-54. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.
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| 6. |
- Chen, Y, et al.
(författare)
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Laser surface modified ductile iron by pulsed Nd:YAG laser beam with two-dimensional array distribution
- 2005
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 245:1-4, s. 316-321
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Tidskriftsartikel (refereegranskat)abstract
- A novel modification layer on the surface of pearlite-ferrite matrix ductile iron was fabricated under irradiation of Nd:YAG laser beam equipped with self-designed diffractive optical element (DOE) which produces a 5×5 two-dimensional array distribution at the focal plane. The microstructure of the layer along the surface and the direction of the layer depth had obvious gradient distribution, and therefore the two-dimensional microhardness map of the layer alternated higher hardness with lower hardness. The results showed that the novel modification layer is expected to have excellent combination of strength and toughness
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| 7. |
- Guo, T. Y., et al.
(författare)
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Three-Dimensional Simulation on Liquid Flow in a Rotating Packed Bed Reactor
- 2017
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 56:28, s. 8169-8179
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Tidskriftsartikel (refereegranskat)abstract
- Rotating packed bed (RPB) reactors, with strong centrifugal acceleration up to several hundred times gravitational acceleration, can greatly intensify the gas-liquid mass transfer efficiency. With the improvement of high performance computer clusters and simulation models, a more precise and comprehensive simulation on the gas-liquid flows in RPBs has been achieved by a three-dimensional model. The volume of fluid (VOF) multiphase model, sliding model (SM), and different turbulence models were used to compute the velocity fields and capture the evolution of the gas-liquid interface in the RPB reactor. The liquid flow behavior, droplet size, liquid phase distribution, specific surface area, and mean residence time (MRT) of the liquid phase within the RPB were studied. Compared with two-dimensional simulations, the three-dimensional simulation model can not only describe the liquid breakage and coalescence processes within RPB reactors more clearly, but also obtain results in more satisfactory agreement with experimental data.
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| 8. |
- Litvinov, Yu.A., et al.
(författare)
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Nuclear physics experiments with ion storage rings
- 2013
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 317:PART B, s. 603-616
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Tidskriftsartikel (refereegranskat)abstract
- In the last two decades a number of nuclear structure and astrophysics experiments were performed at heavy-ion storage rings employing unique experimental conditions offered by such machines. Furthermore, building on the experience gained at the two facilities presently in operation, several new storage ring projects were launched worldwide. This contribution is intended to provide a brief review of the fast growing field of nuclear structure and astrophysics research at storage rings.
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| 9. |
- Liu, Y., et al.
(författare)
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Anthropogenic Aerosols Cause Recent Pronounced Weakening of Asian Summer Monsoon Relative to Last Four Centuries
- 2019
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 46:10, s. 5469-5479
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Tidskriftsartikel (refereegranskat)abstract
- The Asian Summer Monsoon (ASM) affects ecosystems, biodiversity, and food security of billions of people. In recent decades, ASM strength (as represented by precipitation) has been decreasing, but instrumental measurements span only a short period of time. The initiation and the dynamics of the recent trend are unclear. Here for the first time, we use an ensemble of 10 tree ring-width chronologies from the west-central margin of ASM to reconstruct detail of ASM variability back to 1566 CE. The reconstruction captures weak/strong ASM events and also reflects major locust plagues. Notably, we found an unprecedented 80-year trend of decreasing ASM strength within the context of the 448-year reconstruction, which is contrary to what is expected from greenhouse warming. Our coupled climate model shows that increasing anthropogenic sulfate aerosol emissions over the Northern Hemisphere could be the dominant factor contributing to the ASM decrease. Plan Language Summary Monsoonal rainfall has a certain influence on agriculture and industry in the regions of Asian Summer Monsoon (ASM). An understanding of the spatial-temporal variability of the ASM and the associated dynamics is vital for terrestrial ecosystems, water resources, forests, and landscapes. We have developed a 448-year ASM reconstruction back to 1566 CE using 10 tree ring chronologies from the margin region of ASM. We find that historical severe droughts and locust plague disasters during weak ASM events. The recent decreasing ASM trend persisting for over 80 years is unprecedented over the past 448 years. Coupled climate models show that increasing anthropogenic aerosol emissions are the dominant underlying factor. Our aim is that the time series will find a wide range of utility for understanding past climate variability and for predicting future climate change.
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| 10. |
- Moody, G., et al.
(författare)
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Coherent quantum dynamics of excitons in monolayer transition metal dichalcogenides
- 2016
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9781628419818 ; 9746
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Konferensbidrag (refereegranskat)abstract
- Transition metal dichalcogenides (TMDs) have garnered considerable interest in recent years owing to their layer thickness-dependent optoelectronic properties. In monolayer TMDs, the large carrier effective masses, strong quantum confinement, and reduced dielectric screening lead to pronounced exciton resonances with remarkably large binding energies and coupled spin and valley degrees of freedom (valley excitons). Coherent control of valley excitons for atomically thin optoelectronics and valleytronics requires understanding and quantifying sources of exciton decoherence. In this work, we reveal how exciton-exciton and exciton-phonon scattering influence the coherent quantum dynamics of valley excitons in monolayer TMDs, specifically tungsten diselenide (WSe2), using two-dimensional coherent spectroscopy. Excitation-density and temperature dependent measurements of the homogeneous linewidth (inversely proportional to the optical coherence time) reveal that exciton-exciton and exciton-phonon interactions are significantly stronger compared to quasi-2D quantum wells and 3D bulk materials. The residual homogeneous linewidth extrapolated to zero excitation density and temperature is 1:6 meV (equivalent to a coherence time of 0.4 ps), which is limited only by the population recombination lifetime in this sample. (c) (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
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| 11. |
- Smolentsev, Grigory, et al.
(författare)
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Local structure of photoexcited bimetallic complexes refined by quantitative XANES analysis
- 2011
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048. ; 184:3-6, s. 125-128
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Tidskriftsartikel (refereegranskat)abstract
- Photoexcited states of a pyrazolate bridged PtPt dimer and a supramolecular RuCo complex with bipyridine-type ligands were studied using the pump-and-probe X-ray absorption spectroscopy method. The local structure refinement based on the fitting of XANES difference spectra has been performed. The theoretical analysis included the full multiple scattering calculations and the multidimensional interpolation of spectra as a function of structural parameters. The influence of possible correlations between the fraction of molecules in the photoexcited state and structural parameters is discussed. (C) 2011 Elsevier B.V. All rights reserved.
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| 12. |
- Wang, K., et al.
(författare)
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Prevalence of Obesity and Related Factors among Bouyei and Han Peoples in Guizhou Province, Southwest China
- 2015
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the prevalence of general and abdominal obesity and associated factors in Bouyei and Han peoples. A cross-sectional study was carried out in Guizhou province, southwest China in 2012, with multi-stage sampling to enroll 4551 participants aged 20 to 80 years. General and abdominal obesity were defined by World Health Organization (WHO) for Chinese. A design-based analysis was performed to evaluate prevalence of obesity and its related factors. Bouyei people had a significantly lower prevalence of general obesity (4.8% vs. 10.9%, p < 0.05) and abdominal obesity (13.6% vs. 26.8%, p < 0.05) than that in Han people. Prevalence of obesity increased with age until middle-age period and declined thereafter. Men aged 40-49 years group and women aged 50-59 years group have the highest prevalence of general obesity. Prevalence of abdominal obesity was higher than that of general obesity. Middle-age, Higher income, Han people were significantly associated with an increased risk of General/abdominal obesity. Bouyei people had a lower prevalence of general and abdominal obesity than the Han people. Etiological studies should be conducted to determine underlying genetic factors and dietary factors.
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