有限元程序的一种并行化算法

传统的以串行计算机为物质基础的有限元算法分析未能满足科学研究和工程技术发展的需要．并行处理技术的发展为解决此类问题提供了新的契机．机群式并行计算机是当今较为流行的一种并行处理方式．根据有限元法的特点，提出了一种并行有限元算法，并在多处理机分布式内存并行计算机环境下完成了面向对象并行有限元程序的编制．算例表明该算法能大大提高其分析速度，而且算法简单，实现方便．     

GLS coding based security solution to JPEG with the structure of aggregated compression and encryption

There exists close relation among chaos, coding and cryptography. All the three can be combined into a whole as aggregated chaos-based coding and cryptography (ATC) to compress and encrypt data simultaneously. In particular, image data own high redundancy and wide transmission and thereby it is well worth doing research on ATC for image, which is very helpful to real application.JPEG with high compression ratio has not provided security. If JPEG is incorporated into powerful cryptographic features, its application can be further extended. For this reason, in this paper, GLS coding as a special form of ATC, which attains synchronous compression and encryption, is used to modify JPEG and fill its gap. An image is first initialized using DCT, quantization and run-length coding in turn, just as JPEG. Then, it is encoded and encrypted simultaneously by utilizing GLS coding and binary keystream resulting from the chaotic generator. Results demonstrate that our scheme can not only achieve good compression performance but also resist known/chosen-plaintext attacks efficiently.     

A improved F‐expansion method and its application to Kudryashov–Sinelshchikov equation

On the basis of the F‐expansion method with a new sub‐equation and Exp‐function method, an improved F‐expansion method is introduced. As illustrative examples, the exact solutions expressed by exponential function, hyperbolic function of Kudryashov–Sinelshchikov equation for arbitrary α,β are derived. Some previous results are extended. The method is straightforward, concise and is a promising and powerful method for other nonlinear evolution equations in mathematical physics. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis of fused benzimidazole–quinoxalinones via UDC strategy and following the intermolecular nucleophilic substitution reaction

A series of fused benzimidazole–quinoxalinones were synthesized utilizing a one-pot UDC (Ugi/de-protection/cyclization) strategy to form a benzimidazole group with subsequent intermolecular nucleophilic substitution reaction to form quinoxalinone functionality. Using combinations of either a tethered ketone acid or aldehyde acid input the Ugi reaction was shown to afford (1) a ring system through lactamization, (2) a benzimidazole through de-protection and cyclization, and (3) a quinoxalinone through the nucleophilic substitution reaction. Scaffolds were produced in good yields and facile operation.     

Synchronization of delayed complex dynamical networks with impulsive and stochastic effects

In this paper, the globally exponential synchronization of delayed complex dynamical networks with impulsive and stochastic perturbations is studied. The concept named “average impulsive interval” with “elasticity number” of impulsive sequence is introduced to get a less conservative synchronization criterion. By comparing with existing results, in which maximum or minimum of impulsive intervals are used to derive the synchronization criterion, the proposed synchronization criterion increases (or decreases) the impulse distances, which leads to the reduction of the control cost (or enhance the robustness of anti-interference) as the most important characteristic of impulsive synchronization techniques. It is discovered in our criterion that “elasticity number” has influence on synchronization of delayed complex dynamical networks but has no influence on that of non-delayed complex dynamical networks. Numerical simulations including a small-world network coupled with delayed Chua’s circuit are given to show the effectiveness and less conservativeness of the theoretical results.     

Y,Fe共掺杂SrTiO3混合导体材料电阻抗行为研究

采用溶胶-凝胶法制备了单一立方相钙钛矿结构的Y0.06Sr0.94Ti1-xFexO3-δ(x=0.2,0.3,0.4,0.5)混合导体材料,采用交流阻抗法分析了电子-离子总阻抗的Nyquist图,离子阻抗的Nyquist图和Z~lgf频谱图的特性。结果表明,试样以电子电导为主,阻抗随着Fe掺杂量的增大而逐渐减小;从离子阻抗的Z~lgf频谱可以看出,试样离子传导在晶界有一个弛豫过程,Fe的掺杂降低了Y0.06Sr0.94Ti1-xFexO3-δ的弛豫活化能。试样的总电导率和离子电导率都随着Fe的掺杂量的增大而增大,Y0.06Sr0.94Ti0.5Fe0.5O3-δ的总电导率和离子电导率分别为0.088~0.15 S·cm-1和0.00023~0.029 S·cm-1。     

Efficient Degradation of Aqueous Rhodamine B Irradiation Under Indoor Light Using a SiO2–Hypocrellin B Complex

An efficient method for the degradation of the dye Rhodamine B (RhB) is reported. A SiO₂–hypocrellin B (SiO₂–HB) complex was found to work as a catalyst to degrade RhB in aqueous solution at room temperature and atmospheric pressure, over the pH range 1–10, under indoor light conditions. This method is capable of removing 82.68% of RhB within 20 min at pH 9. The SiO₂–HB complex was characterized by both scanning electron microscopy and surface area analysis. The reaction progress was examined using ultrahigh pressure liquid chromatography/mass spectrometry and UV–visible spectroscopy. This process represents an efficient means of decontaminating dye‐containing wastewaters in either highly acidic or weakly alkaline environments.     

Elimination of HBr from CH3Br by Cu＋ and Au＋： A DFT study

The elimination of HBr from CH3Br by ground state of Cu＋ and Au＋ has been investigated by using DFT methods. A mechanism of one-step HBr elimination leading to CuCH2＋ was identified. For the formation of AuCH2＋, besides the one-step mechanism, another two-step HBr elimination pathway through a C-Br bond insertion intermediate was also found, and this pathway is energetically more favorable than the one-step mechanism. The calculated reaction energy barriers show that the formation of AuCH2＋ is energetically much more favorable than the formation of CuCH2＋. The experimental observations are well explained.     

Calibration model transfer for near-infrared spectra based on canonical correlation analysis

In order to solve the calibration transformation problem in near-infrared (NIR) spectroscopy, a method based on canonical correlation analysis (CCA) for calibration model transfer is developed in this work. Two real NIR data sets were tested. A comparative study between the proposed method and piecewise direct standardization (PDS) was conducted. It is shown that the transfer results obtained with the proposed method based on CCA were better than those obtained by PDS when the subset had sufficient samples.     

关于H.Fujimoto一个结果的改进

本文研究了权分担一个公共值集的亚纯函数唯一性问题.利用值分布理论,获得了一个唯一性定理,所获结论改进了H.Fujimoto的一个结果.