Geochemistry and petrogenesis of volcanic rocks from Daimao Seamount (South China Sea) and their tectonic implications

The South China Sea (SCS) experienced three episodes of seafloor spreading and left three fossil spreading centers presently located at 18°N, 17°N and 15.5°N. Spreading ceased at these three locations during magnetic anomaly 10, 8, and 5c, respectively. Daimao Seamount (16.6. Ma) was formed 10. my after the cessation of the 17°N spreading center. Volcaniclastic rocks and shallow-water carbonate facies near the summit of Daimao Seamount provide key information on the seamount's geologic history. New major and trace element and Sr-Nd-Pb isotopic compositions of basaltic breccia clasts in the volcaniclastics suggest that Daimao and other SCS seamounts have typical ocean island basalt-like composition and possess a 'Dupal' isotopic signature. Our new analyses, combined with available data, indicate that the basaltic foundation of Daimao Seamount was formed through subaqueous explosive volcanic eruptions at 16.6. Ma. The seamount subsided rapidly (>. 0.12. mm/y) at first, allowing the deposition of shallow-water, coral-bearing carbonates around its summit and, then, at a slower rate (<. 0.12. mm/y). We propose that the parental magmas of SCS seamount lavas originated from the Hainan mantle plume. In contrast, lavas from contemporaneous seamounts in other marginal basins in the western Pacific are subduction-related

Collective Flow Distributions and Nuclear Stopping in Heavy-ion Collisions at AGS, SPS and RHIC

We study the production of proton, antiproton and net-proton at \AGS, \SPS and \RHIC within the framework non-uniform flow model(NUFM) in this paper. It is found that the system of RHIC has stronger longitudinally non-uniform feature than AGS and SPS, which means that nuclei at RHIC energy region is much more transparent. The NUFM model provides a very good description of all proton rapidity at whole AGS, SPS and RHIC. It is shown that our analysis relates closely to the study of nuclear stopping and longitudinally non-uniform flow distribution of experiment. This comparison with AGS and SPS help us to understand the feature of particle stopping of thermal freeze-out at RHIC experiment.Comment: 16 pages,7 figure

Geometric entanglement from matrix product state representations

An efficient scheme to compute the geometric entanglement per lattice site for quantum many-body systems on a periodic finite-size chain is proposed in the context of a tensor network algorithm based on the matrix product state representations. It is systematically tested for three prototypical critical quantum spin chains, which belong to the same Ising universality class. The simulation results lend strong support to the previous claim [Q.-Q. Shi, R. Or\'{u}s, J. O. Fj{\ae}restad, and H.-Q. Zhou, New J. Phys \textbf{12}, 025008 (2010); J.-M. St\'{e}phan, G. Misguich, and F. Alet, Phys. Rev. B \textbf{82}, 180406R (2010)] that the leading finite-size correction to the geometric entanglement per lattice site is universal, with its remarkable connection to the celebrated Affleck-Ludwig boundary entropy corresponding to a conformally invariant boundary condition.Comment: 4+ pages, 3 figure

On the Nature of X(4260)

We study the property of $X(4260)$ resonance by re-analyzing all experimental data available, especially the $e^+e^- \rightarrow J/\psi\,\pi^+\pi^-,\,\,\,\omega\chi_{c0}$ cross section data. The final state interactions of the $\pi\pi$, $K\bar K$ couple channel system are also taken into account. A sizable coupling between the $X(4260)$ and $\omega\chi_{c0}$ is found. The inclusion of the $\omega\chi_{c0}$ data indicates a small value of $\Gamma_{e^+e^-}=23.30\pm 3.55$eV.Comment: Refined analysis with new experimental data included. 13 page

Dynamic Characteristic Analysis of Doubly-fed Induction Generator Low Voltage Ride-through

AbstractFor studying the impacts of wind turbines integrated into grid, the relation between the protection of doubly-fed induction generator (DFIG) during low voltage fault and the dynamic characteristic of grid is established from the points of generator operation constrains and district grid voltage stability. Then the resistance value and switching strategy of crowbar are discussed. Based on analyzing the electric characteristic of the voltage or current during the short-circuit fault in wind turbines with crowbar switching, the equation to estimate peak current of stator and rotor of DFIG with crowbar switching and the value range of crowbar resistance are derived. The numeric test analyzes the impacts of crowbar switching on district grid voltage stability with different fault types, crowbar switching time and crowbar resistance values. Also the interaction impact of crowbar switching on multi-wind farms is analyzed. The results show that reasonable crowbar resistance value and switching strategy can improve low voltage ride through (LVRT) ability of wind turbines and reduce bad impacts on district grid voltage stability with large-scale crowbar switching of wind farms