Scaling laws and polystyrene networks: a quasi-elastic light scattering study

Randomly crosslinked networks with a range of crosslink densities were prepared by γ-irradiation. Quasielastic light scattering measurements were made on the gels swollen to equilibrium in cyclohexane at 308, 318 and 333 K. The longitudinal osmotic modulus M_os was obtained from the intensity of the dynamically scattered light, and the cooperative diffusion coefficient D_c calculated from the relaxation rate of the autocorrelation function. The concentration dependence of these parameters at the theta temperature was found to be consistent with the scaling predictions, but at higher temperatures where excluded volume conditions prevail, deviations from scaling behaviour were observed. These discrepancies are probably caused by defects in the network structure.     

HEGM: A hierarchical elastic graph matching for hand gesture recognition

A hierarchical scheme for elastic graph matching applied to hand gesture recognition is proposed. The proposed algorithm exploits the relative discriminatory capabilities of visual features scattered on the images, assigning the corresponding weights to each feature. A boosting algorithm is used to determine the structure of the hierarchy of a given graph. The graph is expressed by annotating the nodes of interest over the target object to form a bunch graph. Three annotation techniques, manual, semi-automatic, and automatic annotation are used to determine the position of the nodes. The scheme and the annotation approaches are applied to explore the hand gesture recognition performance. A number of filter banks are applied to hand gestures images to investigate the effect of using different feature representation approaches. Experimental results show that the hierarchical elastic graph matching (HEGM) approach classified the hand posture with a gesture recognition accuracy of 99.85% when visual features were extracted by utilizing the Histogram of Oriented Gradient (HOG) representation. The results also provide the performance measures from the aspect of recognition accuracy to matching benefits, node positions correlation and consistency on three annotation approaches, showing that the semi-automatic annotation method is more efficient and accurate than the other two methods.     

基于SkyEye的嵌入式Linux移植仿真技术研究

在嵌入式系统开发中,经常需要硬件开发板来调测软件,不仅操作繁琐,硬件环境不稳定时问题也很难定位;有时还会遇到软件等待硬件调试,延误开发周期的情况。在PC桌面系统下,探讨了一种基于SkyEye虚拟硬件技术的嵌入式平台仿真技术,介绍如何建立仿真基础环境,编译嵌入式Linux内核,制作根文件系统,编译、配置SkyEye,以S3C6410X为目标机处理器,将Linux内核及文件系统移植到基于SkyEye虚拟的ARM体系架构下,为嵌入式系统的研发探索了一种新的途径。     

基于支持向量回归的动力电池参数辨识

根据铅酸蓄电池在放电过程中内部电化学反应导致外部电特性变化的特点,提出一种基于支持向量机原理的电解液密度辨识模型。利用支持向量机理论非线性回归的特性,简化测量电解液密度的过程,在恶劣环境下检测动力电池的电解液密度更显其优越性。预测实验表明,采用改进的交叉验证预测模型具有泛化能力强、稳定性好的特点,并且在小样本的条件下能达到预期的辨识精度。     

Small-angle neutron scattering from branched epoxide resins

Small-angle neutron scattering experiments in the range of q² from 0.01 to 25 nm⁻² have been carried out on branched epoxide resins based on bisphenol-A at the Institute Laue—Langevin (I.L.L) in Grenoble (q=(4π/λ) sin(θ/2)). Measurements were made with six samples in the range of M_W from 1500 to 19 000 and four concentrations between 1.3 and 10% (w/w) in deuterated diglyme. The results are as follows: (i) The mean square radius of gyration follows a relationship S²_z=4.69×10⁻⁴M^1.20_W (nm²). (ii) In all cases fairly large second virial coefficients A₂ are obtained which, however, decrease strongly with molecular weight. Above M_W=2500, the virial coefficient follows the relationship A₂=1.6M^−0.85_W (mol cm³g⁻²). (ii) The reciprocal particle scattering factor as a function of q² exhibits only a slight upturn and otherwise shows the behaviour of a randomly branched polycondensate. The slight upturn is discussed as being caused by the finite volume of the monomeric unit. Possible reasons for the high exponent in the S²_z versus M_W dependence are briefly discussed.     

基于逐次散射法的海洋-大气矢量辐射传输模式

首先推导了粗糙洋面双向偏振反射模型pBRDF(Bidirectional Polarized Reflectance Distribution Function),并将其与SOSVRT(Successive Order of Scattering Radiative Transfer)矢量辐射传输模式耦合,建立了海洋-大气耦合的矢量辐射传输模式,并对该耦合模式的模拟结果与前人模拟结果进行对比,验证了该耦合模式的可靠性与有效性。不同大气和洋面状态、不同高度的主平面内辐射强度和偏振度的模拟结果表明:pBRDF模型可以很好地模拟不同风速下洋面的偏振反射分布特征;洋面在特定角度具有很高的偏振度,并对大气顶的偏振辐射有很大影响。因此,该耦合模式可以更准确地处理辐射光谱在海洋-大气两种介质间的传输问题,对矢量辐射传输、大气遥感问题的研究有重要意义。     

有限体积法求解立体角离散误差

为解决采用有限体积法求解辐射传输方程时引起离散误差的问题,从有限体积法立体角内热流密度的求解过程出发,运用泰勒级数推导了近似误差的表达式,并分析影响离散误差的各种因素,包括离散射线数,辐射强度分布,假散射及网格比.根据分析结果,采用辐射强度的连续分布模型,模拟了各种因素对误差的影响.结果表明,辐射强度的分布函数对于有限体积法的离散误差有一定程度影响.当增加网格数及减小网格尺寸比时,可以有效地减小离散误差.假散射与离散误差间呈较强的非线性耦合关系.     

电视购物调查分析——以陕西电视台“乐家购物”为例

对"乐家购物"消费者的调查数据用交互式列联表作初步的描述分析,表明随着年龄的增长、教育程度的提高、月收入的增加,选择电视购物的次数都有增加的趋势;构建Logistic回归模型对影响电视购物的因素作深入分析研究,揭示影响消费者选择电视购物的主要因素是年龄和受教育程度,并为电视购物的发展提出建议。     

低雷诺数气液交叉流装置研究（I）——孔流液柱流动特性数值模拟

针对低雷诺数的气液交叉流气体净化过程,提出有效避免二次雾沫夹带的液柱流体力学条件。数值模拟结果表明,液柱表面随着离开孔口的距离而变化,采用公式Lb／d=2．84We^0.694能有效预测液柱的断裂行为。     

Formation mechanism of subtrenches on cone-shaped patterned sapphire substrate

In this paper, the cone-shaped patterned sapphire substrates (PSS) were etched by an inductively couple plasma with BCl 3 as the reacting gas. The influence of the operating pressure and the RF bias power on subtrenches of the cone-shaped PSS and the formation mechanism of subtrenches were investigated. The profiles of patterns were characterized by FESEM (field emission scanning electron microscope). It showed that the subtrench size varied with the operating pressure and the RF bias power. As the operatin...