凸体形状匹配的参考点

本文研究了在平移变换下凸体形状的匹配．通过估计凸体形心与凸体内可测子集形心之间的距离的方法，得到了形心之间距离的不等式和形心是凸体在形状匹配下的参考点的结论．     

像增强器的光生背景噪声对微光目标质心探测精度的影响及其抑制方法

 像增强器作为微光探测器件，在天文目标观测、空间目标捕获、跟踪和瞄准以及生物荧光光谱探测等方面发挥越来越大的作用。重点讨论了在微弱亮度的空间点目标探测应用中，像增强器的光生背景噪声对目标质心探测的影响。实验和分析表明，像增强器的光生背景噪声是由目标信号寄生而来的，并且呈现散粒噪声特性，无法采取屏蔽环境背景杂光、阈值去背景等方法来消除光生背景噪声，对目标信号质心探测的影响很大。提出一种减小这种影响的质心计算方法，实验证明是有效的。     

伽玛函数与一个力学问题的解析解

本文借助质心系动能定理、质心运动定理和伽玛函数Γ(a)的性质,不用计算机和数学软件,得出一个力学问题的解析解.     

Orlicz Brunn-Minkowski理论

本文主要介绍Orlicz Brunn-Minkowski理论,并从下面3个方面介绍该理论:Orlicz投影体和Orlicz质心体、Orlicz加法与其相关体积不等式、Orlicz Minkowski问题.     

素环上导子的线性组合

In this paper we discuss the linear combination of derivations in prime rings which was initiated by Niu Fengwen.Our aim is to improve Niu‘s result.For the proof of the main theorem we generalize a result of Bresar and obtain a lemma that is of independent interest.     

星敏感器技术研究现状及发展趋势

本文综述了星敏感器技术的研究现状和未来发展趋势。首先,总结了国内外星载星敏感器的发展历程。接着,根据星敏感器工作原理,分析讨论了星点质心定位算法、星图识别算法和姿态解算算法等星敏感器关键技术的发展现状。通过讨论星点质心定位精度对星敏感器测量精度影响,分析了星点质心定位算法以及对应误差补偿的研究现状;基于星座特征、字符模式和智能行为,介绍了星图识别算法并进行了对比分析;根据确定姿态解算算法和动态姿态解算算法分析了姿态解算算法的研究现状。最后,对星敏感器的未来发展进行了展望,讨论了航空机载星敏感器、微小型星敏感器和甚高精度星敏感器的发展趋势以及未来重点研究内容。     

Yield Stress Measurement of Dense Pastes with Pipe Transport and Vane

Yield stress is a key rheological parameter of dense paste. Considering practical utility and to estimate the possible slipping flow, yield stress measurements were carried out using the curve extrapolation method and vane method with rheometer in both controlled shear stress (CSS) and controlled shear rate (CSR) model. All measured yield stresses show to increase exponentially with concentration in different scale. The vane method yield stresses are both higher than the extrapolation curve yield stress. For the coal slurry used in this paper, the extrapolation curve yield stress is lower by 17–30% than the dynamic yield stress that obtained under test model CSR. It indicates that wall slip exists in pipeline transportation; meanwhile wall slip can reduce transportation resistance of dense paste to some extent.     

Homothetic transformations and geometric loci: properties of triangles and quadrilaterals

In this paper, we use geometric transformations to find some interesting properties related with geometric loci. In particular, given a triangle or a cyclic quadrilateral, the locus generated by the centroid or by the orthocentre (for triangles) or by the anticentre (for cyclic quadrilaterals) when one vertex moves on the circumcircle of the figure are considered. These loci are studied in paragraphs 3 and 4. By means of the homothetic transformations some properties of triangles and quadrilaterals are found. The study of these properties can be used, with profit, in a classroom activity supported by Dynamic Geometry System.     

Principal component and Tucker3 analyses of high performance liquid chromatography with diode-array detection fingerprints of crude extracts of Erythrina speciosa Andrews leaves

Mixtures of ethanol, dichloromethane, hexane and acetone obtained according to a statistical design have been used to extract substances from Erythrina speciosa Andrew leaves for chromatographic fingerprinting. The plant extracts from each mixture were analyzed by HPLC-DAD providing UV–vis spectra for each chromatographic peak. These chromatograms and spectra for the design mixtures were then treated with principal component (PCA), Tucker3 and PARAFAC analyses. PCA indicated the existence of five different chromatographic fingerprints for the leave extracts depending on the solvent mixture composition. Different chromatographic peak areas were strongly correlated with the mixture proportions of acetone, dichloromethane and ethanol. Tucker3 and PARAFAC analyses were very useful for identifying simultaneous correlations between chromatographic peak areas, spectral band absorbances and solvent proportions. The acetone proportion was highly correlated with the area of the 3.69 min retention time peak and the spectral absorbances between 250 and 260 nm, consistent with the presence of natural polyphenols. The dichloromethane mixture proportion was strongly correlated with the 12.19 min chromatographic peak area and a single spectral absorbance at 201 nm. This spectral absorption is characteristic of the electronic structures of terpenes and alkaloids.