3,897 research outputs found

    Revisit of directed flow in relativistic heavy-ion collisions from a multiphase transport model

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    We have revisited several interesting questions on how the rapidity-odd directed flow is developed in relativistic 197^{197}Au+197^{197}Au collisions at sNN\sqrt{s_{NN}} = 200 and 39 GeV based on a multiphase transport model. As the partonic phase evolves with time, the slope of the parton directed flow at midrapidity region changes from negative to positive as a result of the later dynamics at 200 GeV, while it remains negative at 39 GeV due to the shorter life time of the partonic phase. The directed flow splitting for various quark species due to their different initial eccentricities is observed at 39 GeV, while the splitting is very small at 200 GeV. From a dynamical coalescence algorithm with Wigner functions, we found that the directed flow of hadrons is a result of competition between the coalescence in momentum and coordinate space as well as further modifications by the hadronic rescatterings.Comment: 8 pages, 8 figures, version after major revisio

    Simulating fusion reactions from Coulomb explosions within a transport approach

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    We have studied nuclear fusion reactions from the Coulomb explosion of deuterium clusters induced by high-intensity laser beams within a transport approach. By incorporating the D+D \rightarrow n + He3^3 channel as inelastic collisions based on the stochastic method, we have calibrated the neutron yield from the simulation in a box system with that from the reaction rate equation. After justifying the Coulomb explosion of a single cluster by comparing results with available theoretical limits, we have then investigated the dynamics from Coulomb explosions of systems with different cluster numbers and different deuteron numbers in clusters. We find that the kinetic energy spectrum of deuterons at the final stage is different from that when neutrons are abundantly produced, corresponding to significantly different reaction rates. We also extrapolate the neutron yield result from small systems to large systems based on an intuitive parameterized form and compare with the available experimental result. The present framework can be extended by incorporating more channels, and useful for further studies of nuclear fusion reactions in plasma systems at higher energies reached in more recent experiments.Comment: 10 pages, 9 figure

    (1SR,2RS,3SR,5SR,6RS)-6-[(Z)-1-Acet­oxy-2-phenyl­ethen­yl]-3-eth­oxy-2-phenyl­bicyclo­[3.1.0]hexan-1-yl acetate

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    The mol­ecule of the title compound, C26H28O5, is chiral with five stereogenic centres; however, the centrosymmetric triclinic group gives a racemic crystal. The fused ring system adopta boat conformation in which the cyclo­propane ring plane is roughly perpendicular to the styryl group plane, forming a dihedral angle of 74.78 (19)°. The dihedral angle between the two benzene rings is 77.24 (6)°

    Methyl 2-amino-3,4,5,6-tetra­fluoro­benzoate

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    In the title compound, C8H5F4NO2, synthesized by esterification of 2,3,4,5-tetra­fluoro­anthranilic acid with methanol, an intra­molecular amine N—H⋯Ocarbon­yl hydrogen bond is present, while inter­molecular N—H⋯O hydrogen bonds produce chains in the crystal, which extend along the b-axis direction

    Effect of the Citrus Lycopene β-Cyclase Transgene on Carotenoid Metabolism in Transgenic Tomato Fruits

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    Lycopene β-cyclase (LYCB) is the key enzyme for the synthesis of β-carotene, a valuable component of the human diet. In this study, tomato constitutively express Lycb-1 was engineered. The β-carotene level of transformant increased 4.1 fold, and the total carotenoid content increased by 30% in the fruits. In the transgenic line, the downstream α-branch metabolic fluxes were repressed during the three developmental stages while α-carotene content increased in the ripe stage. Microarray analysis in the ripe stage revealed that the constitutive expression of Lycb-1 affected a number of pathways including the synthesis of fatty acids, flavonoids and phenylpropanoids, the degradation of limonene and pinene, starch and sucrose metabolism and photosynthesis. This study provided insight into the regulatory effect of Lycb-1 gene on plant carotenoid metabolism and fruit transcriptome
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