2,586 research outputs found

    Rapidity bin multiplicity correlations from a multi-phase transport model

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    The central-arbitrary bin and forward-backward bin multiplicity correlation patterns for Au+Au collisions at sNN\sqrt{s_{NN}} = 7.7−62.47.7-62.4 GeV are investigated within a multi-phase transport (AMPT) model. An interesting observation is that for sNN<19.6\sqrt{s_{NN}} <19.6 GeV Au+Au collisions, these two correlation patterns both have an increase with the pseudorapidity gap, while for sNN>19.6\sqrt{s_{NN}} >19.6 GeV Au+Au collisions, they decrease. We mainly discuss the influence of different evolution stages of collision system on the central-arbitrary bin correlations, such as the initial conditions, partonic scatterings, hadronization scheme and hadronic scatterings. Our results show that the central-arbitrary bin multiplicity correlations have different responses to partonic phase and hadronic phase, which can be suggested as a good probe to explore the dynamical evolution mechanism of the hot dense matter in high-energy heavy-ion collisions.Comment: 7pages, 6 figures, accepted for publication in EPJ

    Light anti-nuclei production in pp collisions at s\sqrt{s}=7 and 14 TeV

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    A dynamically constrained coalescence model based on the phase space quantization and classical limit method was proposed to investigate the production of light nuclei (anti-nuclei) in non-single diffractive (NSD) pp collisions at s\sqrt{s}=7 and 14 TeV. This calculation was based on the final hadronic state in the PYTHIA and PACIAE model simulations, the event sample consisted of 1.2×108\times 10^8 events in both simulations. The PACIAE model calculated Dˉ\bar D yield of 6.247×10−5\times 10^{-5} in NSD pp collisions at s\sqrt{s}=7 TeV is well comparing with the ALICE rough datum of 5.456×10−5\times 10^{-5}. It indicated the reliability of proposed method in some extent. The yield, transverse momentum distribution, and rapidity distribution of the Dˉ\bar D, 3Heˉ^3{\bar{He}}, and Λˉ3Hˉ_{\bar\Lambda} ^3{\bar H} in NSD pp collisions at s\sqrt{s} =7 and 14 TeV were predicted by PACIAE and PYTHIA model simulations. The yield resulted from PACIAE model simulations is larger than the one from PYTHIA model. This might reflect the role played by the parton and hadron rescatterings.Comment: 5 pages, 2 figure

    Big Data Value Engineering for Business Model Innovation

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    Big data value engineering for business model innovation requires a drastically different approach as compared with methods for engineering value under existing business models. Taking a Design Science approach, we conducted an exploratory study to formulate the requirements for a method to aid in engineering value via innovation. We then developed a method, called Eco-ARCH (Eco-ARCHitecture) for value discovery. This method is tightly integrated with the BDD (Big Data Design) method for value realization, to form a big data value engineering methodology for addressing these requirements. The Eco-ARCH approach is most suitable for the big data context where system boundaries are fluid, requirements are ill-defined, many stakeholders are unknown, design goals are not provided, no central architecture pre-exists, system behavior is non-deterministic and continuously evolving, and co-creation with consumers and prosumers is essential to achieving innovation goals. The method was empirically validated in collaboration with an IT service company in the Electric Power industry

    Distribution of Spectral Lags in Gamma Ray Bursts

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    Using the data acquired in the Time To Spill (TTS) mode for long gamma-ray bursts (GRBs) collected by the Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory (BATSE/CGRO), we have carefully measured spectral lags in time between the low (25-55 keV) and high (110-320 keV) energy bands of individual pulses contained in 64 multi-peak GRBs. We find that the temporal lead by higher-energy gamma-ray photons (i.e., positive lags) is the norm in this selected sample set of long GRBs. While relatively few in number, some pulses of several long GRBs do show negative lags. This distribution of spectral lags in long GRBs is in contrast to that in short GRBs. This apparent difference poses challenges and constraints on the physical mechanism(s) of producing long and short GRBs. The relation between the pulse peak count rates and the spectral lags is also examined. Observationally, there seems to be no clear evidence for systematic spectral lag-luminosity connection for pulses within a given long GRB.Comment: 20 pages, 4 figure

    The Role of the Lactadherin in Promoting Intestinal DCs Development In Vivo and Vitro

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    Lactadherin, as one of the immune components in the breast milk, might play a role in the intestinal immune system of newborn. Therefore, we investigated the effect of lactadherin-feeding in early time on the development of intestinal immune system compared with naturally rearing and artificially rearing (non-lactadherin). In the present study, we observed that the Peyer's Patches (PP) from the pups of artificially reared group with lactadherin added were characterized by an excess of OX62+CD4+SIRP+ DC cells and a higher expression of CD3+CD4+CD25+T cells. Additionally, this study also demonstrated that IL-10 production was dramatically increased when lactadherin was present in culture medium compared with lactadherin-absent culture. These results suggested that lactadherin could adjust intestinal DCs activity, induce CD3+CD4+CD25+T cell differentiation, and enhance IL-10 production
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