Runge–Kutta discontinuous Galerkin method using WENO limiters II: Unstructured meshes

In [J. Qiu, C.-W. Shu, Runge–Kutta discontinuous Galerkin method using WENO limiters, SIAM Journal on Scientific Computing 26 (2005) 907–929], Qiu and Shu investigated using weighted essentially non-oscillatory (WENO) finite volume methodology as limiters for the Runge–Kutta discontinuous Galerkin (RKDG) methods for solving nonlinear hyperbolic conservation law systems on structured meshes. In this continuation paper, we extend the method to solve two-dimensional problems on unstructured meshes, with the goal of obtaining a robust and high order limiting procedure to simultaneously obtain uniform high order accuracy and sharp, nonoscillatory shock transition for RKDG methods. Numerical results are provided to illustrate the behavior of this procedure.     

Quantum Pattern Recognition with Probability of 100%

In recent years there has been an increasing focus on the quantum pattern recognition, especially quantum multi-pattern recognition in computer science. This paper presents a new quantum multi-pattern recognition method based on the improved Grover’s algorithm. This method not only details the process of quantum multi-pattern recognition using several unitary operators, but also introduces a new design scheme of initializing quantum state and quantum encoding on the pattern set. If the rate of the number of the recognized pattern on the total patterns is over 1/3, this new method can recognize multi-pattern simultaneously with the probability of 100%. Mathematic calculations and simulation results on the case show that the proposed method can accomplish multi-pattern recognition with the probability of 100%. However, the recognition probability of other pattern recognition methods is impossible to reach 1.     

Characterization and magnetic exchange observation for CoFe2O4–CoFe2 nanocomposite microfibers

The magnetic hard-soft CoFe₂O₄–CoFe₂ nanocomposite microfibers have been synthesized by the sol–gel and partial reduction process, where CoFe₂O₄ ferrite is the hard phase with a grain size range from 43 to 62 nm and CoFe₂ alloy the soft phase with grain sizes around 30 nm. These nanocomposite microfibers exhibit the magnetization behavior like a single phase magnetic material, and the magnetic exchange coupling effects are observed between the hard and soft phases. The specific saturation magnetization of CoFe₂O₄–CoFe₂ nanocomposite microfibers shows an increase tendency with the increasing weight fraction of CoFe₂, while the coercivity is consequently reduced. The nanocomposite microfibers have a maximum remanence 51.7 Am²/kg when the phase contents of CoFe₂ around 28 wt% and CoFe₂O₄ about 72 wt%.     

Preparation and optical properties of high-quality oriented of Al and Er co-doped ZnO thin films

High-quality c-axis oriented Al and Er co-doped ZnO films were prepared on the quartz glasses by sol?Cgel method. In order to obtain the optimal processing parameters for the growth of the oriented film, an L₁₆ (4⁵) orthogonal experimental design was chosen. The experimental results show the rank of 5-factors as follows: Er at.%?>?the number of coating layer?>?annealing temperature?>?Al at.%?>?the concentration of the sol. The Al and Er co-doped film prepared using the optimal parameters exhibits the preferential orientation along the c-axis perpendicular to the substrate surface. In addition, the structural, morphological and optical properties of the films were studied by X-ray diffraction, scanning electron microscopy, and UV?Cvisible spectrophotometer, respectively. The photoluminescence spectra were also used to characterize the luminescence properties of the samples. It is found that when ZnO was co-doped with 7?% Al and 1.5?% Er, the blue emission centered at 465?nm disappears and the green emission centered at 547?nm increases with a blue shift, resulted from the rapid reducing of the interstitial Zn defect, and increasing of the oxygen defects and vacancies caused by Al³⁺ and Er³⁺ dopants.