3,313 research outputs found

    Photoinduced Surface Relief Grating Formation for a Single Crystal of 4-Aminoazobenzene

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    Photoinduced surface relief grating (SRG) formation for a single crystal of 4-aminoazobenzene was investigated. It was found that SRG could be inscribed on the (001) surface of the crystal, which might suggest that the photoinduced SRG formation is a general phenomenon observed for single crystals of azobenzene-based molecules as well as for azobenzene-based amorphous systems. In addition, the dependences of the SRG formation upon the orientation of the sample crystal and upon the polarization of the writing beams were found to be different from those observed for previously reported crystalline systems

    Pre- and post-initiation modulating effects of green tea ingestion on rat hepatocarcinogenesis

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    The purpose of this study was to investigate the effects of green tea ingestion on hepatocarcinogenesis before and after its initiation. Male Sprague-Dawley rats were fed an AIN76A diet with or without green tea. Initiation was induced by a single dose (200 mg/kg) of diethylnitrosamine at week 4 and 0.02% (w/w) 2-acetylaminofluorene was supplied in the diets. The control group had free access to water for 13 weeks (CTR13). Tea infusion was provided from the beginning of the experiment for 13 weeks (PRE13) or from the post-initiation stage until week 13 (POST13). Three other groups (CTR24, PRE24 and POST24) were added to examine the longer-term effects (24 weeks) with the same experimental design. The percentage area of liver sections that were positive for hepatic placental glutathione S-transferase (GST-P), which was used as a marker of preneoplastic lesions, was smaller in PRE13 (20.2 ± 5.0%, mean ± SD) and POST13 (26.0 ± 4.8%) than in CTR13 (33.2 ± 5.8%, p<0.05). Over the longer period, the GST-P lesions were significantly smaller for both PRE24 and POST24 (21.6 ± 8.5% and 22.2 ± 4.0%, respectively) than for CTR24 (28.6 ± 5.1%, p<0.05), but there was no significant difference between PRE24 and POST24. The liver content of thiobarbituric acid reactive substances was significantly lower in the tea groups than in the controls (p<0.05). However, no significant differences were observed among groups of GST activity. The results show that tea consumption exhibits a stronger short-term initiation-inhibiting ability in liver carcinogenesis, but over a longer period, the preventive effects of green tea ingestion do not differ in post- and pre-initiation

    First analysis of anisotropic flow with Lee--Yang zeroes

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    We report on the first analysis of directed and elliptic flow with the new method of Lee--Yang zeroes. Experimental data are presented for Ru+Ru reactions at 1.69 AGeV measured with the FOPI detector at SIS/GSI. The results obtained with several methods, based on the event-plane reconstruction, on Lee--Yang zeroes, and on multi-particle cumulants (up to 5th order) applied for the first time at SIS energies, are compared. They show conclusive evidence that azimuthal correlations between nucleons and composite particles at this energy are largely dominated by anisotropic flow.Comment: 5 pages, 3 figures, submitted to Phys. Rev. C Rapid Co

    Isospin dependence of relative yields of K+K^+ and K0K^0 mesons at 1.528 AGeV

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    Results on K+K^+ and K0K^0 meson production in 4496^{96}_{44}Ru + 4496^{96}_{44}Ru and 4096^{96}_{40}Zr + 4096^{96}_{40}Zr collisions at a beam kinetic energy of 1.528AA GeV, measured with the FOPI detector at GSI-Darmstadt, are investigated as a possible probe of isospin effects in high density nuclear matter. The measured double ratio (K+/K0K^+/K^0)Ru_{Ru}/(K+/K0K^+/K^0)Zr_{Zr} is compared to the predictions of a thermal model and a Relativistic Mean Field transport model using two different collision scenarios and under different assumptions on the stiffness of the symmetry energy. We find a good agreement with the thermal model prediction and the assumption of a soft symmetry energy for infinite nuclear matter while more realistic transport simulations of the collisions show a similar agreement with the data but also exhibit a reduced sensitivity to the symmetry term.Comment: 5 pages, 3 figures. accepted for publication in Phys. Rev.

    Two-proton small-angle correlations in central heavy-ion collisions: a beam-energy and system-size dependent study

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    Small-angle correlations of pairs of protons emitted in central collisions of Ca + Ca, Ru + Ru and Au + Au at beam energies from 400 to 1500 MeV per nucleon are investigated with the FOPI detector system at SIS/GSI Darmstadt. Dependences on system size and beam energy are presented which extend the experimental data basis of pp correlations in the SIS energy range substantially. The size of the proton-emitting source is estimated by comparing the experimental data with the output of a final-state interaction model which utilizes either static Gaussian sources or the one-body phase-space distribution of protons provided by the BUU transport approach. The trends in the experimental data, i.e. system-size and beam energy dependences, are well reproduced by this hybrid model. However, the pp correlation function is found rather insensitive to the stiffness of the equation of state entering the transport model calculations.Comment: 9 pages, 8 figures, accepted at Eur. Phys. Journ.

    Searching Toward Pareto-Optimal Device-Aware Neural Architectures

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    Recent breakthroughs in Neural Architectural Search (NAS) have achieved state-of-the-art performance in many tasks such as image classification and language understanding. However, most existing works only optimize for model accuracy and largely ignore other important factors imposed by the underlying hardware and devices, such as latency and energy, when making inference. In this paper, we first introduce the problem of NAS and provide a survey on recent works. Then we deep dive into two recent advancements on extending NAS into multiple-objective frameworks: MONAS and DPP-Net. Both MONAS and DPP-Net are capable of optimizing accuracy and other objectives imposed by devices, searching for neural architectures that can be best deployed on a wide spectrum of devices: from embedded systems and mobile devices to workstations. Experimental results are poised to show that architectures found by MONAS and DPP-Net achieves Pareto optimality w.r.t the given objectives for various devices.Comment: ICCAD'18 Invited Pape

    Charged pion production in 4496^{96}_{44}Ru+4496^{96}_{44}Ru collisions at 400A and 1528A MeV

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    We present transverse momentum and rapidity spectra of charged pions in central Ru + Ru collisions at 400AA and 1528AA MeV. The data exhibit enhanced production at low transverse momenta compared to the expectations from the thermal model that includes the decay of Δ(1232)\Delta(1232)-resonances and thermal pions. Modification of the Δ\Delta-spectral function and the Coulomb interaction are necessary to describe the detailed shape of the transverse momentum spectra. Within the framework of the thermal model, the freeze-out radii of pions are similar at both beam energies. The IQMD model reproduces the shapes of the transverse momentum and rapidity spectra of pions, but the predicted absolute yields are larger than in the measurements, especially at lower beam energy.Comment: 12 pages, 11 figure

    Strange meson production in Al+Al collisions at 1.9A GeV

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    The production of K+^+, K^- and φ\varphi(1020) mesons is studied in Al+Al collisions at a beam energy of 1.9A GeV which is close or below the production threshold in NN reactions. Inverse slopes, anisotropy parameters, and total emission yields of K±^{\pm} mesons are obtained. A comparison of the ratio of kinetic energy distributions of K^- and K+^+ mesons to the HSD transport model calculations suggests that the inclusion of the in-medium modifications of kaon properties is necessary to reproduce the ratio. The inverse slope and total yield of ϕ\phi mesons are deduced. The contribution to K^- production from ϕ\phi meson decays is found to be [17 ±\pm 3 (stat) 7+2^{+2}_{-7} (syst)] %. The results are in line with previous K±^{\pm} and ϕ\phi data obtained for different colliding systems at similar incident beam energies.Comment: 16 pages, 11 figure

    Measurement of K(892)0K^*(892)^0 and K0K^0 mesons in Al+Al collisions at 1.9AA GeV

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    New measurement of sub-threshold K(892)0K^*(892)^0 and K0K^0 production is presented. The experimental data complete the measurement of strange particles produced in Al+Al collisions at 1.9AA GeV measured with the FOPI detector at SIS/GSI. The K(892)0K^*(892)^0 / K0K^0 yield ratio is found to be 0.0315±0.006(stat.)±0.012(syst.)0.0315\pm 0.006 (\mathrm{stat.})\pm 0.012 (\mathrm{syst.}) and is in good agreement with the UrQMD model prediction. These measurements provide information on in-medium cross section of K+K^+ - π\pi^- fusion which is the dominant process on sub-threshold K(892)0K^*(892)^0 production.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev.
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