A multiresolution finite volume scheme for two-dimensional hyperbolic conservation laws

In this paper, high-resolution finite volume schemes are combined with an adaptive mesh technique inspired by multiresolution analysis to improve the computational efficiency for two-dimensional hyperbolic conservation laws. The method is conservative. Moreover, it is stable which is proven numerically in this paper. The computational grid is dynamically adapted so that higher spatial resolution is automatically allocated to regions where strong gradients are observed. Using this proposed scheme, we compute several two-dimensional model problems and a compressive rate ranging from about 5–10 is observed in all simulations.     

High-speed video capture by a single flutter shutter camera using three-dimensional hyperbolic wavelets

Based on the consideration of easy achievement in modern sensors, this paper further exploits the possibility of the recovery of high-speed video (HSV) by a single flutter shutter camera. Taking into account different degrees of smoothness along the spatial and temporal dimensions of HSV, this paper proposes to use a three-dimensional hyperbolic wavelet basis based on Kronecker product to jointly model the spatial and temporal redundancy of HSV. Besides, we incorporate the total variation of temporal correlations in HSV as a prior knowledge to further enhance our reconstruction quality. We recover the underlying HSV frames from the observed low-speed coded video by solving a convex minimization problem. The experimental results on simulated and real-world videos both demonstrate the validity of the proposed method.     

{Qs}{Q（＇）s} Molecular States in QCD Sum Rules

We systematically investigate the mass spectra of {Qs}{Q（＇）s} molecular states in the framework of QCD sum rules. The interpolating currents representing the molecular states are proposed. Technically, contributions of the operators up to dimension six are included in operator product expansion （OPE）. The masses for molecular states with various {Qs}{Q（＇）s} configurations are presented. The result 4.36 ± 0.08 Ge V for theDs＊ Ds0- ＊ molecular state is consistent with the mass 4350＋4.6 -5.1± 0.7 MeV of the newly observed X（4350）, which could support X（4350） interpreted as a D＊D＊so molecular state.     

On the dynamics of locally resonant sonic composites

The sound attenuation in a sonic composite is studied using a new method that combines the features of the piezoceramic theory, cnoidal method and genetic algorithms. A sonic composite consists of an array of acoustic scatterers embedded in an epoxy matrix. Acoustic scatterers are piezoceramic hollow spheres made from functionally graded materials – the Reddy and cosine graded hollow spheres. We show that stable attenuation bands may coexist with different patterns of dynamics, including chaos. In order to extend the method towards a tool for analyzing the sound attenuation in sonic composites, the behavior of a real sonic composite is simulated. The results concerning the full band-gaps have been validated by experimental data.     

SHPB实验中端面摩擦效应研究

选取硅橡胶、聚氨酯泡沫、Comp.B炸药、PBX-HMX(97%)炸药以及6061-T6铝合金五种材料试样,对分离式霍普金森压杆（SHPB）实验技术中的端面摩擦效应进行了研究。实验结果表明,SHPB实验技术中的端面摩擦效应与材料的性质相关。另外,基于各向同性弹性理论,运用能量守恒法对SHPB实验中的端面摩擦效应进行了机理分析,研究表明,材料泊松比、端面摩擦系数、试样长径比、轴向应变是SHPB实验中影响端面摩擦效应的四个因素。     

A bijection between ordered trees and bicoloured ordered trees

A bijection is introduced between ordered trees and bicoloured ordered trees, which maps leaves in an ordered tree to odd height vertices in the related tree. Consequently, a bijection between two sets of bridges specified with four parameters is derived.     

Effect of mutual-injection ways on phase locking of arrays of two mutually injected fiber lasers: theoretical investigation

The effect of mutual-injection ways on phase locking of arrays of two mutually injected fiber lasers is studied theoretically. The phase-locked states of arrays with different ways of mutual injection are given analytically. It is found that different ways of mutual injection will result in different phase-locked states. The relationships between phase locking and ways of mutual injection are also discussed. The results indicate that the unconditionally phase-locked states can only be formed at the reflectors (i.e., fiber Bragg gratings [FBGs] or output faces) linking directly with the couplers. It is also found that only some of these arrays can make two output laser beams phase-locked unconditionally, while the other arrays can only make two output laser beams phase-locked with some conditions satisfied.     

约化密度矩阵及其在量子信息处理中的应用

密度矩阵在量子力学中主要是扩展了态矢量的概念.约化密度矩阵是通过对整个系统中的密度矩阵的某一子系求部分迹得到的.本文首先介绍了约化密度矩阵的定义,然后指出约化密度矩阵在纠缠态的定义、两体系统中量子纠缠的度量、系统与环境耦合造成的退相干的物理机制等量子信息前沿领域方面的应用.     

Generation of multi-atom W states via Raman transitionin an optical cavity

A simple scheme is proposed to generate the W state of N Λ-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared perfectly by turning on a classical coupling field for an appropriate time. Compared with the previous ones, our scheme requires neither individual laser addressing of the atoms, nor demand for controlling N atoms to go through an optical cavity simultaneously with a constant velocity. We investigate the influence of cavity decay using the quantum jump approach and show that the preparation time decreases and the success probability increases with atom number because of a collective enhancement of the coupling.     

Application of the vector ε and ρ extrapolation methods in the acceleration of the Richardson-Lucy algorithm

The vector ε and ρ extrapolation methods are applied in accelerating the convergence of the Richardson-Lucy (R-L) algorithm and its damped version. The theory and implementation are discussed in detail, and relevant numerical results are given, including the cases of noise-free images and images corrupted by the Poisson noise. The results show that the vector ε and ρ extrapolations of 9 orders can speed the convergence quite efficiently, and the ρ(9) method is more powerful than the ε(9) method for noisy degraded images. The extra computation burden due to the extrapolation is limited, and is well paid back by the accelerated convergence. The performances of these two methods are compared with the famous automatic acceleration method. For noise-free degraded images, the vector ε(9) and ρ(9) methods are more stable than the automatic method. For noisy degraded images, the damped R-L algorithm accelerated by vector ρ(9) or automatic methods is more powerful, and the instability of the automatic method is restrained by the damping strategy. We explain the instability of the method in accelerating the normal R-L algorithm by the numerical noise due to its frequent applications in the run.