Rip/singularity free cosmology models with bulk viscosity

In this paper we present two concrete models of non-perfect fluid with bulk viscosity to interpret the observed cosmic accelerating expansion phenomena, avoiding the introduction of exotic dark energy. The first model we inspect has a viscosity of the form ${\zeta} = {\zeta}_0 + ({\zeta}_1-{\zeta}_2q)H$ by taking into account of the decelerating parameter q, and the other model is of the form ${\zeta} = {\zeta}_0 + {\zeta}_1H + {\zeta}_2H^2$. We give out the exact solutions of such models and further constrain them with the latest Union2 data as well as the currently observed Hubble-parameter dataset (OHD), then we discuss the fate of universe evolution in these models, which confronts neither future singularity nor little/pseudo rip. From the resulting curves by best fittings we find a much more flexible evolution processing due to the presence of viscosity while being consistent with the observational data in the region of data fitting. With the bulk viscosity considered, a more realistic universe scenario is characterized comparable with the {\Lambda}CDM model but without introducing the mysterious dark energy.Comment: 9 pages, 6 figures, submitted to EPJ-

Three-Particle Correlations from Parton Cascades in Au+Au Collisions

We present a study of three-particle correlations among a trigger particle and two associated particles in Au + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV using a multi-phase transport model (AMPT) with both partonic and hadronic interactions. We found that three-particle correlation densities in different angular directions with respect to the triggered particle (`center', `cone', `deflected', `near' and `near-away') increase with the number of participants. The ratio of `deflected' to `cone' density approaches to 1.0 with the increasing of number of participants, which indicates that partonic Mach-like shock waves can be produced by strong parton cascades in central Au+Au collisions.Comment: 9 pages, 6 figures; Final version to appear in Physics Letters

Properties and Performance of Two Wide Field of View Cherenkov/Fluorescence Telescope Array Prototypes

A wide field of view Cherenkov/fluorescence telescope array is one of the main components of the Large High Altitude Air Shower Observatory project. To serve as Cherenkov and fluorescence detectors, a flexible and mobile design is adopted for easy reconfiguring of the telescope array. Two prototype telescopes have been constructed and successfully run at the site of the ARGO-YBJ experiment in Tibet. The features and performance of the telescopes are presented

Structure-properties relationships in solution-processable single-material molecular emitters for efficient green organic light-emitting diodes

The electroluminescent properties of a series of solution-processable fluorescent molecular emitters have been systematically investigated. While the introduction of the electron-deficient benzothiadiazole unit in the structure confers efficient electron-injection on the emitter materials, they exhibit different hole-transport properties. The device characteristics of the OLEDs based on these various emitters are discussed on the basis of (i) the energy levels of their HOMO and LUMO and (ii) their hole-transport properties in relation with the charge-transport and blocking properties of the electron- and hole-transport layers. (C) 2012 Elsevier B.V. All rights reserved

The newly observed open-charm states in quark model

Comparing the measured properties of the newly observed open-charm states D(2550), D(2600), D(2750), D(2760), D_{s1}(2710), D_{sJ}(2860), and D_{sJ}(3040) with our predicted spectroscopy and strong decays in a constituent quark model, we find that: (1) the D(2\,^1S_0) assignment to D(2550) remains open for its too broad width determined by experiment; (2) the D(2600) and $D_{s1}(2710)$ can be identified as the 2\,^3S_1-1\,^3D_1 mixtures; (3) if the D(2760) and D(2750) are indeed the same resonance, they would be the D(1\,^3D_3); otherwise, they could be assigned as the D(1\,^3D_3) and $D^\prime_2(1D)$, respectively; (4) the $D_{sJ}(2860)$ could be either the $D_{s1}(2710)$'s partner or the D_s(1\,^3D_3); and (5) both the $D_{s1}(2P)$ and $D^\prime_{s1}(2P)$ interpretations for the $D_{sJ}(3040)$ seem likely. The $E1$ and $M1$ radiative decays of these sates are also studied. Further experimental efforts are needed to test the present quarkonium assignments for these new open-charm states.Comment: 26 pages,7 figures, journal versio

Recognizing basal cell carcinoma on smartphone‐captured digital histopathology images with a deep neural network

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154530/1/bjd18026.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154530/2/bjd18026_am.pd

Di-hadron azimuthal correlation and Mach-like cone structure in parton/hadron transport model

In the framework of a multi-phase transport model (AMPT) with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles have been studied by the mixing-event technique. The momentum ranges of these particles are $3< p^{trig}_T< 6$ GeV/$c$ and $0.15< p_{T}^{assoc} < 3$ GeV/$c$ (soft), or $2.5<p^{trig}_T<$ 4 GeV/$c$ and $1< p_{T}^{assoc} < 2.5$ GeV/$c$ (hard) in Au + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. A Mach-like structure has been observed in correlation functions for central collisions. By comparing scenarios with and without parton cascade and hadronic rescattering, we show that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure of the associated particle azimuthal correlations. The contribution of hadronic dynamical process can not be ignored in the emergence of Mach-like correlations of the soft scattered associated hadrons. However, hadronic rescattering alone cannot reproduce experimental amplitude of Mach-like cone on away-side, and the parton cascade process is essential to describe experimental amplitude of Mach-like cone on away-side. In addition, both the associated multiplicity and the sum of $p_{T}$ decrease, whileas the $$ increases, with the impact parameter in the AMPT model including partonic dynamics from string melting scenario.Comment: 9 pages, 5 figures; Physics Letters B 641, 362-367 (2006

A Dithienylbenzothiadiazole Pure Red Molecular Emitter with Electron Transport and Exciton Self-Confinement for Nondoped Organic Red-Light-Emitting Diodes

An amorphous photoluminescent material based on a dithienylbenzothiadiazole structure has been used for the fabrication of organic red-light-emitting diodes. The synergistic effects of the electron-transport ability and exciton confinement of the emitting material allow for the fabrication of efficient pure-red-light-emitting devices without a hole blocker

Possible implications of the channeling effect in NaI(Tl) crystals

The channeling effect of low energy ions along the crystallographic axes and planes of NaI(Tl) crystals is discussed in the framework of corollary investigations on WIMP Dark Matter candidates. In fact, the modeling of this existing effect implies a more complex evaluation of the luminosity yield for low energy recoiling Na and I ions. In the present paper related phenomenological arguments are developed and possible implications are discussed at some extent.Comment: 16 pages, 10 figures, preprint ROM2F/2007/15, submitted for publicatio