脑磁共振成像断层组合全息技术的研究

采用激光全息分层分区二步法，将一组磁共振成像片按不同层次组合成一张全息图，可在普通白炽灯下观察到清晰的三维层析透射图，以辅助医师准确，迅速地判断出患病部位的情况和位置。     

Socio-economic determinants of HIV/AIDS pandemic and nations efficiencies

This paper examines the influence and direction of social and economic determinants of the HIV/AIDS global epidemic across nations and assesses each country’s efficiency in battling the pandemic. The initial dataset consisted of 151 countries with five dependent variables and 90 explanatory variables (reduced to 50 after extensive exploratory data analysis of missing value patterns, undesirable multi-colinearities and multivariate outliers).     

Approximation Methods for Supervised Learning

Let ρ be an unknown Borel measure defined on the space Z := X × Y with X ⊂ ℝ^d and Y = [-M,M]. Given a set z of m samples z_i =(x_i,y_i) drawn according to ρ, the problem of estimating a regression function f_ρ using these samples is considered. The main focus is to understand what is the rate of approximation, measured either in expectation or probability, that can be obtained under a given prior f_ρ ∈ Θ, i.e., under the assumption that f_ρ is in the set Θ, and what are possible algorithms for obtaining optimal or semioptimal (up to logarithms) results. The optimal rate of decay in terms of m is established for many priors given either in terms of smoothness of f_ρ or its rate of approximation measured in one of several ways. This optimal rate is determined by two types of results. Upper bounds are established using various tools in approximation such as entropy, widths, and linear and nonlinear approximation. Lower bounds are proved using Kullback-Leibler information together with Fano inequalities and a certain type of entropy. A distinction is drawn between algorithms which employ knowledge of the prior in the construction of the estimator and those that do not. Algorithms of the second type which are universally optimal for a certain range of priors are given.     

新疆石榴中磷含量的测定及其对人体健康的影响

采用钼蓝光度法借助722型分光光度计在波长660nm处测定了新疆石榴中磷的含量.实验结果表明:新疆石榴籽粒和果皮的总含磷量及石榴籽粒的含磷量分别为12.798mg/100g和11.033mg/100g,完全符合石榴中的标准磷含量为8.9-13mg/100g范围.而石榴汁含磷量为8.68×10-2mg/100mL,含磷量比较低.研究确定了新疆石榴中磷的含量,证明了新疆石榴独特的食用和药用价值和对人体健康的积极影响.     

用统计直线法测定中药薄荷油的旋光率

用计算机辅助的回归直线方法测定了中药薄荷油的旋光率，这种方法是用不同浓度薄荷油的样品建立的，获得了满意的结果。     

MgB_2超导体参量的拟和简化计算

关联长度ξ、临界Cooper对速度、London穿透深度λ以及临界电流密度jc与温度T的变化关系一直是二硼化镁超导体倍受关注的焦点。文中在各向同性的GL理论的框架内对以上参量随温度的变化关系通过计算机进行拟和,得出了数学形式相对简单、物理内涵又比较清晰的数学表达式,达到了对MgB2超导体参量拟和简化计算的目的。     

Nanoscale Co/Cu Multilayers Investigated by Analytical TEM and AES

 Concentration profiles of sputtered and pulsed laser deposited nanoscale Co/Cu multilayers have been measured by EDXS and EELS line scans in scanning mode at electron microscopic cross section foils and by AES depth profile analysis. The interpretation of the results has been supported by model calculations. After deposition, the pulsed laser deposited multilayers are stronger mixed than the sputtered layers. They decompose during annealing.     

Strip-based regression: A method to obtain comprehensive co-polymer architectures from matrix-assisted laser desorption ionisation-mass spectrometry data

A method aimed to obtain the relative abundances of all molecular species in highly overlapped mass spectra is presented. Its performance is demonstrated with an example of matrix-assisted laser desorption ionization (MALDI) spectra obtained from a polysterene-co-polyisoprene sample, retrieving the full co-polymer architecture. The method is based on a multiple regression operation, applied locally at consecutive regions. The method is designed in such a way that it is not necessary to locate regions in the spectrum that are not influenced by adjacent ones. This increases its applicability, since the method is able to tackle the analysis of highly complex spectra, tending to minimise the need of user intervention. The method allows to correct for non-idealities (such as wrong calibration) or to adjust the variations of spectral resolution with mass. Additionally, the algorithm calculates the precision of the computation in a straightforward way.     

基于输入-输出数据的重心法模糊系统及其泛逼近性

研究基于输入-输出数据的重心法模糊系统及其泛逼近性.首先,将一组单输入-单榆出数据转换成模糊推理规则,通过选择适当的模糊蕴涵算子生成模糊关系,再利用这种模糊关系求出二雄随机变量的联合概率密度函数.当将模糊蕴涵分别取为Larsen蕴涵和Mamdani蕴涵时,分别得到了两种具体的概率密度函数(称之为Larsen分布和Mamdani分布).其次,利用这两种概率分布.分别求出了对应的两种回归函数,指出这种回归函数实际上是模糊控制中的重心法模糊系统.我们分别给出了这种模糊系统具有泛逼近性的充分条件.从而进一步揭示了模糊系统的概率论意义.     

Calibration in atomic spectrometry: A tutorial review dealing with quality criteria,weighting procedures and possible curvatures

Calibration is required to obtain analyte concentrations in atomic spectrometry. To take full benefit of it, the adequacy of the coefficient of determination r² is discussed, and its use is compared with the uncertainty due to the prediction bands of the regression. Also discussed from a tutorial point of view are the influence of the weighting procedure and of different weighting factors, and the comparison between linear and quadratic regression to cope with curvatures. They are illustrated with examples based on the use of ICP-AES with nebulization and laser ablation, and of LIBS. Use of a calibration graph over several orders of magnitude may be problematic as well as the use of a quadratic regression to cope with possible curvatures. Instrument softwares that allow reprocessing of the calibration by selecting standards around the expected analyte concentration are convenient for optimizing the calibration procedure.