一种求解约束优化问题的演化规划算法

提出了一种新的求解约束优化问题的演化算法--基于混合策略求解约束优化问题的演化规划算法（CMSEP）.借鉴了Mezura-Montes的算法中直接比较的约束处理方法,为求解位于边界附近的全局最优解采用多样性保护机制,允许一定比例最好不可行解进入下一代种群,混合策略变异机制用于指导算法快速搜索过程.标准测试函数的实验结果验证了算法的通用性和有效性.     

Analysis of the surface plasmon resonance of a single core-shelled nanocomposite by surface integral equations

To investigate the interactions of an illuminating light with a single nanocomposite (a core-shelled nanoparticle) in the range of ultraviolet (UV) to near infrared (NIR), a set of new surface integral equations was derived from the Stratton–Chu formulation of Maxwell's equations for a two-dimensional TM-mode problem. These integral equations belong to Fredholm equations of the second kind. Using the boundary-element method (BEM), these equations are solved to obtain the surface components (the tangential magnetic field, the normal displacement field and the tangential electric field) along the multi-connected interfaces (host/shell and shell/core) simultaneously. Two main structures of the core-shelled nanocomposite are studied by BEM; one is a nanoparticle of metallic core (Au or Ag) with an oxide shell (SiO₂ or ZrO₂), and the other structure is a silica core (SiO₂) with a metallic shell (e.g. Au or Ag). The numerical results illustrate a red-shift effect on the surface plasmon resonance (SPR) of the former structure can be induced by covering a high-permittivity shell on a metallic nanoparticle. For the latter, the red shift of SPR is caused by thinning the thickness of the metallic shell. This is to say by tuning the compositions and the configurations of the nanocomposites, the peak position and the linewidth of the SPR can be manipulated on demand.     

基于生存簇识别和预测的生存态势感知模型

可生存系统安全态势的形势日趋严峻,增强生存性的前提是识别出目标系统的生存态势,该文构建了一种基于生存簇识别和预测的生存态势感知模型。首先,对生存态势数据采用Ward增强聚类法实现不同服务等级生存簇的分类和识别;其次,使用自回归积分滑动平均（ARIMA）模型预测目标系统生存态势的未来趋势,并对预测结果进行了残差修正;最后,结合事前识别和事后预测实现了对可生存系统生存态势的感知。仿真实验表明,该模型具有良好识别效果和较高的预测准确度。     

Two Keggin compounds constructed from tri −/tetra-nuclear Cu clusters linked mono copper(II)-substituted phosphomolybdates

Two new compounds based on mono copper(II)-substituted phosphomolybdate, [Cu₄(tea)₆(H₄PMo₁₁CuO₃₉)(PMo₁₂O₄₀)]₂·33H₂O (1) and [Cu₃(tea)₆(H₂O)₂(H₂PMo₁₁CuO₃₉)₂]₂·30H₂O (2) (tea = 2- [1,2,4]triazol-4-yl-ethylamine), have been synthesized under hydrothermal conditions. Compound 1 owns tetra-nuclear clusters [Cu₄(tea)₆], linking a pair mono copper(II)-substituted and saturated Keggin anions to form a 2D structure. Compound 2 contains tri-nuclear clusters [Cu₃(tea)₆], fusing four mono copper(II)-substituted anions to construct a discrete four-membered cycle structure.     

Networked control systems for multi-input plants based on polar logarithmic quantization

This paper investigates the use of polar logarithmic quantization (PLQ) for multi-input systems, and the corresponding design issues for the underlying networked control system (NCS). It is shown that the PLQ induces sector bounded nonlinear uncertainties in multiplicative and relative forms for vector-valued analog signals, similar to those in the scalar case. For the two-input NCS, optimal quantization is obtained through minimization of the quantization error that is quantified explicitly. The results are extended to more than two-input NCSs with an upper bound derived for the quantization error. Feedback stabilization and control of the NCS are also investigated under the PLQ at the plant input under state feedback. The coarsest quantization density (CQD) is studied and obtained. Results in this paper are illustrated by a numerical example.     

Synthesis of SnAgCu nanoparticles with low melting point by the chemical reduction method

SnAgCu alloy with low melting point and good soldering property is a good candidate for the Sn/Pb eutectic. In this paper, SnAgCu nanoparticles were synthesized by a chemical reduction method. The particle size and the melting point are controlled by modifying the process parameters, including reaction temperature, surfactant concentration and dropping speed of precursor. The lowest melting onset temperature is observed at 199.1 °C, which is 18 °C lower than that of commercially available SnAgCu solder alloy. The tensile strength of the as-synthesized reaches 34.3 MPa, which reveals a good solderability property.     

A weighted full-reference image quality assessment based on visual saliency

In full reference image quality assessment (IQA), the images without distortion are usually employed as reference, while the structures in both reference images and distorted images are ignored and all pixels are equally treated. In addition, the role of human visual system (HVS) is not taken account into subjective IQA metric. In this paper, a weighted full-reference image quality metric is proposed, where a weight imposed on each pixel indicates its importance in IQA. Furthermore, the weights can be estimated via visual saliency computation, which can approximate the subjective IQA via exploiting the HVS. In the experiments, the proposed metric is compared with several objective IQA metrics on LIVE release 2 and TID 2008 database. The results demonstrate that SROCC and PLCC of the proposed metric are 0.9647 and 0.9721, respectively,which are higher than other methods and it only takes 427.5 s, which is lower than that of most other methods.     

Two new Keggin-type polyoxometalate-based entangled coordination networks constructed from metal-organic chains with dangling arms

Two new polyoxometalate(POM)-based entangled coordination networks with chemical formula of [Mn₂(H₂O)₂(BBPTZ)₅][SiW₁₂O₄₀] (1) and [Ni₂(H₂O)₂(BBPTZ)₅][SiMo₁₂O₄₀]·6H₂O (2) (BBPTZ = 4.4′-bis(1,2,4-triazol-1-ylmethyl)biphenyl), were prepared in a hydrothermal reaction system. Compounds 1–2 were characterized by elemental analyses, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. In compound 1, dangling arms thread in quadrangular window of the adjacent 2-D layers, thus resulting in a rare 2-D → 3-D polythreading motif. Compound 2 exhibits a rare 2-D → 3-D zipper-closing motif. Using the degradation of methylene blue (MB) as the model, the photocatalytic activities of compounds 1–2 were investigated. Both compounds show efficient catalytic activity for the degradation of MB with the order of 2 > 1. It is found that the POM species of compounds 1–2 play the main role in the photocatalytic degradation process.     

Inorganic-organic hybrid supramolecular material based on the highest connection of a Keggin arsenotungstate with electro-/photo-catalytic properties

An extraordinary supramolecular hybrid material based on the Keggin arsenotungstate, (Hbimb)₃[AsW₁₂O₄₀]·H₂O (1) (bimb = 1,4-bis(imidazol-l-yl)butane) has been synthesized under hydrothermal condition and characterized by elemental analysis, infrared (IR), thermogravimetry (TG), X-Ray Diffractomer (XRD), and single-crystal XRD. In compound 1 the {AsW₁₂O₄₀} cluster is linked to 14 organic ligands through their surface oxygen atoms, which are further embraced by 20 polyanions analogs to form a tightly packed 3D supramolecular network with a (4⁵·6)(4⁵²·6³⁸·8)(4⁹·6)₂ topology via strong hydrogen bonds and supramolecular interactions. Compound 1 represents the highest connectivity of Keggin supramolecular arsenotungstate, which exhibits electrocatalytic behaviors for reduction of H₂O₂ and high efficiency degradation capability for two typical dyes methylene blue (MB) and rhodamine B (RhB) under UV light.