Finer discrimination of brain activation with local multivariate distance

The organization of human brain function is diverse on different spatial scales. Various cognitive states are always represented as distinct activity patterns across the specific brain region on fine scales. Conventional univariate analysis of functional MRI data seeks to determine how a particular cognitive state is encoded in brain activity by analyzing each voxel separately without considering the fine-scale patterns information contained in the local brain regions. In this paper, a local multivariate distance mapping (LMDM) technique is proposed to detect the brain activation and to map the fine-scale brain activity patterns. LMDM directly represents the local brain activity with the patterns across multiple voxels rather than individual voxels, and it employs the multivariate distance between different patterns to discriminate the brain state on fine scales. Experiments with simulated and real fMRI data demonstrate that LMDM technique can dramatically increase the sensitivity of the detection for the fine-scale brain activity patterns which contain the subtle information of the experimental conditions.     

银杏叶的生物活性成分及其在功能性食品中的应用

该文对银杏叶的主要生物活性成分与化学成分及在功能性食品中应用方面的研究进行了综述。     

环境功能负离子涂料的制备及抗菌性能研究

采用溶胶-凝胶法以Na2SiO3为包覆剂成功地制备了分散性优良负离子粉体,通过不同的添加量,研制能够产生最大负离子浓度的功能涂料。进行了负离子涂料的抗菌性研究,实验结果表明负离子材料具有抗菌性,抗菌效果与涂料的负离子产生量、负离子材料粒径、涂料的距离密切相关,并从微观上对负离子杀菌进行了分析,验证了负离子的生物学效应。     

I Have A Dream的功能语法分析

自韩礼德于20世纪60年代创立系统功能语法以来，话语分析已经逐渐引起人们的关注。利用系统功能语法的理论框架，对马丁·路德金《我有一个梦》的演讲名篇做语篇的纯理功能实例分析，验证了系统功能语法在演讲语篇分析中的实用性和可操作性。     

带紧扰动的增生算子的特征值问题

运用Leray-Schauder度的理论研究了带紧扰动的增生算子的特征值问题，并得到了正、负的特征值．所得结果改进并推广了Guan和Kartsatos的某些结果，他们只是得到了正的特征值．     

The functional central limit theorem for strong near-epoch dependent random variables

The functional central limit theorem for strong near-epoch dependent sequences of random variables is proved.The conditions given improve on previous results in the literature concerning dependence and heterogeneity.     

Theoretical study on Fe-Al clusters: geometric structure, bonding law and electronic structures

Structures of the small Fe-Al clusters with different atom proportion are calculated using the B3LYP method in density functional theory (DFT). Calculated results show that the Al atoms lose electrons easily while the Fe atoms capture electrons easily. The most stable geometry is the bonding between Fe and Fe atoms and between Fe and Al atoms with the largest possibility, and the cluster stability law with the same atom proportion accords with the change of the highest occupied molecular orbital (HOMO) energy and the entropy of cluster system. Moreover, the electronic structure study of the ground-state Fe3Al and Fe2CrAl clusters shows that the substitution of Cr atom for the Fe atom located at the next neighboring site of Al atom reduces localized electrons not only between Al atom and the next neighboring Cr atom, but also between Al atom and the nearest neighboring Fe atom. Although the substitution increases the plasticity and the magnetism of intermetallic compound, the stability of the system slightly decreases. Our theoretical results agree well with the experimental results.     

时滞差分系统两种测度的稳定性

利用Liapunov泛函方法建立了无限时滞差分系统基于两种测度的一致稳定和一致渐近稳定性判据，并运用所得的结果讨论了一个具体的无限时滞差分系统的一致稳定和一致渐近稳定性，所得的结果推广和发展了这一方向的现有结论。     

关于NFDE(D,F)稳定性的注记

对具无限时滞的中立型泛函数分方程，去掉F有界的条件，证得了其零解为一致渐近稳定的结果，进而将此结果推广到NFDE（D，f)关于部分分变元稳定性的情形。     

用判别式法求函数y=(ax2+bx+c)/(a1x2+b1x+c1)值域的几种方法

给出求函数y=(ax^2 bx c)／(a1x^2 b1x c1)值域的简洁的、程式化的方法。