| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Chen, Li-li, et al.
(författare)
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Multilayered polyelectrolyte-coated gold nanorods as multifunctional optical contrast agents for cancer cell imaging
- 2010
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Ingår i: Journal of Zhejiang University: Science B. - 1673-1581. ; 11:6, s. 417-422
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Tidskriftsartikel (refereegranskat)abstract
- We report the application of multilayered polyelectrolyte-coated gold nanorods (GNRs) as multifunctional optical contrast agents for cancer cell imaging. The surface modification of GNRs improves their chemical stability and facilitates them to be taken up by cancer cells through electrostatic interaction. The unique longitudinal surface plasmon resonance property of GNRs makes them suitable as both "scattering contrast agents" and "Raman contrast agents". In our experiments, the staining of GNRs in cells was further confirmed by dark field microscopy and Raman microscopy. Our experiment results indicated that GNRs have great potential as multifunctional "optical contrast agents" for future in vivo animal imaging.
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| 4. |
- Kang, Jian, et al.
(författare)
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Understanding in the morphology and tensile behavior of isotactic polypropylene cast films with different stereo-defect distribution
- 2014
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Ingår i: Journal of polymer research. - : Springer Science and Business Media LLC. - 1022-9760 .- 1572-8935. ; 21:6, s. 485-
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Tidskriftsartikel (refereegranskat)abstract
- In this study, two iPP resins with similar molecular weight and average isotacticity but different uniformities of stereo-defect distribution were used in the production of cast films. The crystalline morphology and orientation, and tensile behavior during room temperature stretching of the cast films were investigated by scanning electronic microscopy (SEM), 2D-wide angle X-ray diffraction (2D-WAXD) and 2D-small-angle X-ray scattering (2D-SAXS). It was found that under fixed processing condition, iPP with more uniform stereo-defect distribution (PP2) favors the formation of row nucleated lamellar structure during cast film production, and therefore exhibiting hard-elastic deformation behavior during stretching; meanwhile, the sample with less uniform stereo-defect distribution (PP1) shows un-oriented spherulitical morphology in the cast film, and typical plastic deformation behavior during stretching. The crystallization and rheological analysis on the iPP raw materials revealed that, the uniformity of stereo-defect distribution determines the ability of nucleation and crystallization, and further influences the response of the crystalline morphology to the elongation effect of cast film production process, which is of great importance in the structure-property design in the production of iPP membranes.
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| 5. |
- Li, Wu Lue, et al.
(författare)
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Multiple Origins and Genomic Basis of Complex Traits in Sighthounds
- 2023
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 40:8
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Tidskriftsartikel (refereegranskat)abstract
- Sighthounds, a distinctive group of hounds comprising numerous breeds, have their origins rooted in ancient artificial selection of dogs. In this study, we performed genome sequencing for 123 sighthounds, including one breed from Africa, six breeds from Europe, two breeds from Russia, and four breeds and 12 village dogs from the Middle East. We gathered public genome data of five sighthounds and 98 other dogs as well as 31 gray wolves to pinpoint the origin and genes influencing the morphology of the sighthound genome. Population genomic analysis suggested that sighthounds originated from native dogs independently and were comprehensively admixed among breeds, supporting the multiple origins hypothesis of sighthounds. An additional 67 published ancient wolf genomes were added for gene flow detection. Results showed dramatic admixture of ancient wolves in African sighthounds, even more than with modern wolves. Whole-genome scan analysis identified 17 positively selected genes (PSGs) in the African population, 27 PSGs in the European population, and 54 PSGs in the Middle Eastern population. None of the PSGs overlapped in the three populations. Pooled PSGs of the three populations were significantly enriched in "regulation of release of sequestered calcium ion into cytosol"(gene ontology: 0051279), which is related to blood circulation and heart contraction. In addition, ESR1, JAK2, ADRB1, PRKCE, and CAMK2D were under positive selection in all three selected groups. This suggests that different PSGs in the same pathway contributed to the similar phenotype of sighthounds. We identified an ESR1 mutation (chr1: g.42,177,149-T > C) in the transcription factor (TF) binding site of Stat5a and a JAK2 mutation (chr1: g.93,277,007-T > A) in the TF binding site of Sox5. Functional experiments confirmed that the ESR1 and JAK2 mutation reduced their expression. Our results provide new insights into the domestication history and genomic basis of sighthounds.
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| 6. |
- Liang, Suzhe, et al.
(författare)
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Tailoring the Optical Properties of Sputter-Deposited Gold Nanostructures on Nanostructured Titanium Dioxide Templates Based on In Situ Grazing-Incidence Small-Angle X-ray Scattering Determined Growth Laws
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:12, s. 14283-14295
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Tidskriftsartikel (refereegranskat)abstract
- Gold/titanium dioxide (Au/TiO2) nanohybrid materials have been widely applied in various fields because of their outstanding optical and photocatalytic performance. By state-of-the-art polymer templating, it is possible to make uniform nanostructured TiO2 layers with potentially large-scale processing methods. We use customized polymer templating to achieve TiO2 nanostructures with different morphologies. Au/TiO2 hybrid thin films are fabricated by sputter deposition. An indepth understanding of the Au morphology on the TiO2 templates is achieved with in situ grazing-incidence small-angle X-ray scattering (GISAXS) during the sputter deposition. The resulting Au nanostructure is largely influenced by the TiO2 template morphology. Based on the detailed understanding of the Au growth process, characteristic distances can be selected to achieve tailored Au nanostructures at different Au loadings. For selected sputter-deposited Au/TiO2 hybrid thin films, the optical response with a tailored localized surface plasmon resonance is demonstrated.
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| 7. |
- Liang, Suzhe, et al.
(författare)
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Template-Induced Growth of Sputter-Deposited Gold Nanoparticles on Ordered Porous TiO2 Thin Films for Surface-Enhanced Raman Scattering Sensors
- 2022
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 5:5, s. 7492-7501
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Tidskriftsartikel (refereegranskat)abstract
- Ordered porous gold/titanium dioxide (Au/TiO2) hybrid nanostructured films are specifically interesting in large-scale applications using localized surface plasmon resonances (LSPRs) and surface-enhanced Raman scattering (SERS). Deposition of Au nanoparticles via sputter deposition is one of the promising technologies to establish optically active sites at low cost in combination with nanostructured TiO2 films. In this work, we investigate the optical response of sputter-deposited Au/TiO2 nanohybrid thin films with a focus on the plasmonic response and application as molecular sensors. The LSPR peak red shifts with an increasing thickness of deposited Au. The Raman intensity of deposited molecules, probed with rhodamine 6G (R6G), depends on the deposited gold thickness. It has its maximum at an effective Au thickness of 3.4 nm. To elucidate the origin of this behavior, we apply in situ grazing-incidence small-angle X-ray scattering (GISAXS) to investigate the growth kinetics of Au on a TiO2 template during sputter deposition. On the basis of time-resolved GISAXS, the growth characteristics of sputter-deposited Au on a TiO2 template with a final effective Au layer thickness around the percolation threshold is described with the well-known four-stage model of nucleation and cluster formation, diffusion-mediated growth, adsorption-mediated growth, and grain growth. The maximum in SERS intensity is corroborated by the existence and optimal size of hot spots in the narrow space occurring between the sputter-deposited Au clusters, on staying below the percolation threshold. On the basis of the growth laws extracted, we give a guideline for tailoring the ordered porous Au/TiO2 nanohybrid thin films for SERS sensor applications.
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| 8. |
- Liu, Zhengfa, et al.
(författare)
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Mixed Event-Frame Vision System for Daytime Preceding Vehicle Taillight Signal Measurement Using Event-Based Neuromorphic Vision Sensor
- 2022
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Ingår i: Journal of Advanced Transportation. - : Hindawi Limited. - 0197-6729 .- 2042-3195. ; 2022
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Tidskriftsartikel (refereegranskat)abstract
- An important aspect of the perception system for intelligent vehicles is the detection and signal measurement of vehicle taillights. In this work, we present a novel vision-based measurement (VBM) system, using an event-based neuromorphic vision sensor, which is able to detect and measure the vehicle taillight signal robustly. To the best of our knowledge, it is for the first time the neuromorphic vision sensor is paid attention to for utilizing in the field of vehicle taillight signal measurement. The event-based neuromorphic vision sensor is a bioinspired sensor that records pixel-level intensity changes, called events, as well as the whole picture of the scene. The events naturally respond to illumination changes (such as the ON and OFF state of taillights) in the scene with very low latency. Moreover, the property of a higher dynamic range increases the sensor sensitivity and performance in poor lighting conditions. In this paper, we consider an event-driven solution to measure vehicle taillight signals. In contrast to most existing work that relies purely on standard frame-based cameras for the taillight signal measurement, the presented mixed event/frame system extracts the frequency domain features from the spatial and temporal signal of each taillight region and measures the taillight signal by combining the active-pixel sensor (APS) frames and dynamic vision sensor (DVS) events. A thresholding algorithm and a learned classifier are proposed to jointly achieve the brake-light and turn-light signal measurement. Experiments with real traffic scenes demonstrate the performance of measuring taillight signals under different traffic conditions with a single event-based neuromorphic vision sensor. The results show the high potential of the event-based neuromorphic vision sensor being used for optical signal measurement applications, especially in dynamic environments.
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| 9. |
- Song, Jiao-Jiao, et al.
(författare)
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The 4f-Hybridization Strength in CemMnIn3m+2n Heavy-Fermion Compounds Studied by Angle-Resolved Photoemission Spectroscopy
- 2021
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Ingår i: Chinese Physics Letters. - : IOP Publishing. - 0256-307X .- 1741-3540. ; 38:10
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Tidskriftsartikel (refereegranskat)abstract
- We systemically investigate the nature of Ce 4f electrons in structurally layered heavy-fermion compounds CemMnIn3m+2n (with M = Co, Rh, Jr, and Pt, m = 1, 2, n = 0-2), at low temperature using on-resonance angle-resolved photoemission spectroscopy. Three heavy quasiparticle bands f(0), f(7/2)(1) and f(5/2)(1), are observed in all compounds, whereas their intensities and energy locations vary greatly with materials. The strong f(0) states imply that the localized electron behavior dominates the Ce 4f states. The Ce 4f electrons are partially hybridized with the conduction electrons, making them have the dual nature of localization and itinerancy. Our quantitative comparison reveals that the f(5/2)(1)-f (0) intensity ratio is more suitable to reflect the 4f-state hybridization strength.
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| 10. |
- Sun, Li, et al.
(författare)
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Influence of Cr layer thickness on the static and dynamic performances of Tb/Cr/Ni80Fe20 structure
- 2017
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 695, s. 1324-1328
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Tidskriftsartikel (refereegranskat)abstract
- Using the vibrating sample magnetometer and ex situ vector network analyzer ferromagnetic resonance, the static and dynamic magnetic properties of Tb (4 nm)/Cr (t(Cr))/Ni80Fe20 (12 nm) trilayers with different thickness of Cr layer (from 0.2 to 4.0 nm) were investigated comparing with those of Ni80Fe20 film. From the results of in-plane static magnetic hysteresis loops, we analyzed the soft magnetic properties and in-plane anisotropy, along with obtaining the saturation magnetization (M-s) which shows no obvious reducing and a modulation akin to RKKY coupling. By fitting the relationship of resonance field and linewidth versus resonance frequency, the effective magnetization 4 pi M-eff, gyromagnetic ratio gamma, and effective damping coefficient (alpha(eff)) were extracted. It is worthwhile to mention that the inserting of ultrathin Cr layer (0.2 nm) enhanced the above parameters obviously, which then backed down towards their values in Ni80Fe20 film with increasing the thickness of Cr layer as a result of the weakening magnetic proximity effect and the decreasing spin-pumping effect in trilayers. Finally, they became flattening with the Cr layer thicker than 1 nm where oscillations are also observed in the value of g and aeff. Interestingly, the oscillations in aeff and g are consistent with each other, which implies the damping mechanism mainly related to the spin-orbit coupling originating from the indirect interaction between Tb and Ni80Fe20. In addition, the inhomogeneous broadening (Delta H-0) were determined to be very small which further ascertain the accurate of the aeff.
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