A novel explicit-implicit coupled solution method of SWE for long-term river meandering process induced by dam break

YesLarge amount of sediment deposits in the reservoir area can cause dam break, which not only leads to an immeasurable loss to the society, but also the sediments from the reservoir can be transported to generate further problems in the downstream catchment. This study aims to investigate the short-to-long term sediment transport and channel meandering process under such a situation. A coupled explicit-implicit technique based on the Euler-Lagrangian method (ELM) is used to solve the hydrodynamic equations, in which both the small and large time steps are used separately for the fluid and sediment marching. The main feature of the model is the use of the Characteristic-Based Split (CBS) method for the local time step iteration to correct the ELM traced lines. Based on the solved flow field, a standard Total Variation Diminishing (TVD) finite volume scheme is applied to solve the sediment transportation equation. The proposed model is first validated by a benchmark dambreak water flow experiment to validate the efficiency and accuracy of ELM modelling capability. Then an idealized engineering dambreak flow is used to investigate the long-term downstream channel meandering process with nonuniform sediment transport. The results showed that both the hydrodynamic and morphologic features have been well predicted by the proposed coupled model.This research work is supported by Sichuan Science and Technology Support Plan (2014SZ0163), Start-up Grant for the Young Teachers of Sichuan University (2014SCU11056), and Open Research Fund of the State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University (SKLH 1409; 1512)

Potential use of electrical somatosensory modality for BCI

INTRODUCTION: P300 is commonly used in noninvasive brain computer interface (BCI). Most P300 based BCIs were focus on visual and auditory stimulation [1]. Several previous reports present the potential use of vibrotactile stimulus for P300 BCI [2,3]. As an alternative, electrical somatosensory stimuli can be used for BCI ...published_or_final_versio

Interactions of energetic electrons with ULF waves triggered by interplanetary shock: Van Allen Probes observations in the magnetotail

Abstract We present in situ observations of a shock-induced substorm-like event on 13 April 2013 observed by the newly launched Van Allen twin probes. Substorm-like electron injections with energy of 30-500 keV were observed in the region from L∼5.2 to 5.5 immediately after the shock arrival (followed by energetic electron drift echoes). Meanwhile, the electron flux was clearly and strongly varying on the ULF wave time scale. It is found that both toroidal and poloidal mode ULF waves with a period of 150 s emerged following the magnetotail magnetic field reconfiguration after the interplanetary (IP) shock passage. The poloidal mode is more intense than the toroidal mode. The 90 phase shift between the poloidal mode Br and Ea suggests the standing poloidal waves in the Northern Hemisphere. Furthermore, the energetic electron flux modulations indicate that the azimuthal wave number is ∼14. Direct evidence of drift resonance between the injected electrons and the excited poloidal ULF wave has been obtained. The resonant energy is estimated to be between 150 keV and 230 keV. Two possible scenaria on ULF wave triggering are discussed: vortex-like flow structure-driven field line resonance and ULF wave growth through drift resonance. It is found that the IP shock may trigger intense ULF wave and energetic electron behavior at L∼3 to 6 on the nightside, while the time profile of the wave is different from dayside cases

Heavy-tailed statistics in short-message communication

Short-message (SM) is one of the most frequently used communication channels in the modern society. In this Brief Report, based on the SM communication records provided by some volunteers, we investigate the statistics of SM communication pattern, including the interevent time distributions between two consecutive short messages and two conversations, and the distribution of message number contained by a complete conversation. In the individual level, the current empirical data raises a strong evidence that the human activity pattern, exhibiting a heavy-tailed interevent time distribution, is driven by a non-Poisson nature.Comment: 4 pages, 4 figures and 1 tabl

Fidelity susceptibility and long-range correlation in the Kitaev honeycomb model

We study exactly both the ground-state fidelity susceptibility and bond-bond correlation function in the Kitaev honeycomb model. Our results show that the fidelity susceptibility can be used to identify the topological phase transition from a gapped A phase with Abelian anyon excitations to a gapless B phase with non-Abelian anyon excitations. We also find that the bond-bond correlation function decays exponentially in the gapped phase, but algebraically in the gapless phase. For the former case, the correlation length is found to be $1/\xi=2\sinh^{-1}[\sqrt{2J_z -1}/(1-J_z)]$, which diverges around the critical point $J_z=(1/2)^+$.Comment: 7 pages, 6 figure

Quantum double of Heisenberg-Weyl algebra, its universal R-matrix and their representations

In this paper a new quasi-triangular Hopf algebra as the quantum double of the Heisenberg-Weyl algebra is presented.Its universal R-matrix is built and the corresponding representation theory are studied with the explict construction for the representations of this quantum double. \newpageComment: 12 page

Formulation and characterization of biocompatible and stable I.V. itraconazole nanosuspensions stabilized by a new stabilizer polyethylene glycol-poly(β-Benzyl-L-aspartate) (PEG-PBLA)

Abstract Amphiphilic block copolymers, PEG-PBLA with different molecular weights, were synthesized and used as new stabilizers for Itraconazole nannosuspensions (ITZ-PBLA-Nanos). ITZ-PBLA-Nanos were prepared by the microprecipitation-high pressure homogenization method, and the particle size and zeta potential were measured using a ZetaSizer Nano-ZS90. Morphology and crystallinity were studied using TEM, DSC and powder X-ray. The effect of the PEG-to-PBLA ratio, and the drug-to-stabilizer ratio were investigated to obtain the optimal formulation. It was found that the optimal length of hydrophobic block was 25 BLA-NCA molecules and the optimal ratio of drug/stabilizer was 1:1, where the resulted average particle size of ITZ-PBLA-Nanos was 262.1 ± 7.13 nm with a PDI value of 0.163 ± 0.011. The images of TEM suggest that ITZ-PBLA-Nanos were rectangular in shape. ITZ existed as crystals in the nanoparticles as suggested by the DSC and XRD results. Compared with the crude drug suspensions, the dissolution rate of ITZ nanocrystals, was significantly increased and was similar to Sporanox® injection. The ITZ-PBLA-Nanos also demonstrated better dilution stability and storage stability compared with ITZ-F68-Nanos. The particle size of ITZ-PBLA-Nanos did not change significantly after incubated in rat plasma for 24 h which is a good attribute for I.V. administration. Acute toxicity tests showed that ITZ-PBLA-Nanos has the highest LD50 compared with ITZ-F68-Nanos and Sporanox® injection. ITZ-PBLA-Nanos also showed stronger inhibiting effect on the growth of Candida albicans compared with Sporanox® injection. Therefore, PEG-PBLA has a promising potential as a biocompatible stabilizer for ITZ nanosuspensions and potentially for other nanosuspensions as well

Exact solution of gyration radius of individual's trajectory for a simplified human mobility model

Gyration radius of individual's trajectory plays a key role in quantifying human mobility patterns. Of particular interests, empirical analyses suggest that the growth of gyration radius is slow versus time except the very early stage and may eventually arrive to a steady value. However, up to now, the underlying mechanism leading to such a possibly steady value has not been well understood. In this Letter, we propose a simplified human mobility model to simulate individual's daily travel with three sequential activities: commuting to workplace, going to do leisure activities and returning home. With the assumption that individual has constant travel speed and inferior limit of time at home and work, we prove that the daily moving area of an individual is an ellipse, and finally get an exact solution of the gyration radius. The analytical solution well captures the empirical observation reported in [M. C. Gonz`alez et al., Nature, 453 (2008) 779]. We also find that, in spite of the heterogeneous displacement distribution in the population level, individuals in our model have characteristic displacements, indicating a completely different mechanism to the one proposed by Song et al. [Nat. Phys. 6 (2010) 818].Comment: 4 pages, 4 figure