借助于四维坐标的球极平面投影验证SO(4,2)与SU(2,2)间的同态特性

本文借助于四维坐标的球极平面投影,将氢原子变换为一个六维空间中的一个四维谐振子。从而验证了SO(4,2)与SU(2,2)之间的同态特性。     

金属在硼簇化合物中的作用

金属硼原子簇化合物包括金属硼烷、金属碳硼烷及其衍生物,分子几何构型千变万化。一个或多个金属原子(主族或过渡元素)束缚在硼骨架或碳硼骨架上,在作硼或碳硼骨架的稳定剂,或作合成的试剂时,金属所起的作用是很重要的。     

芳叔胺体系引发乙烯类单体聚合的机理——自旋捕集ESR法

采用自旋捕集ESR技术和紫外光谱法,研究了N,N-二甲基苯胺(DMA)-苄基氯(BC)引发甲基丙烯酸甲酯(MMA)自由基聚合的机理;DMA对MMA、丙烯酸甲酯(MA)、苯乙烯(St)及α-甲基苯乙烯(α-MeSt)烯类单体的引发作用。在60℃、无氧条件下、DMA-BC-MMA体系中可产生自由基其中仅有R3参与引发反应,由此证实了以前所提出的引发机理。DMA单独存在下与MMA、α-MeSt这些带有α-甲基的乙烯类单体也可形成活泼的自由基R3,并引发聚合;若与不带有α-甲基的乙烯类单体,如MA、St,则不能形成自由基R3,因此它们不能被引发聚合。     

SURFACE SPIN WAVES FORSEMI—INFINITE MAGNETIC SEMICONDUCTOR WITH A MAGNETIC IMPURITY LAYER IN THE NARROW—BAND LTMIT

The s-d (or s-f) Heisenberg interaction modal is used to investigate the localized surface spin waves in semi-infinite magnetic semiconductor with a single impurity layer in the narrow-band limit. The dispersion relations of localized surface spin wave (LSSW) excitations are obtained by use of Green‘s function theory and the transfer matrix method, The characteristic results in some particular cases are discussed.     

基本粒子与单元粒子Ⅱ．基本粒子的量子数及其在反应中的变化规律

本文在基本粒子是由单元粒子组成的、基本粒子反应是单元粒子对生对灭、对转化和重新组合过程的假设基础上，导出了轻子和强子都适用的通用盖尔曼——西岛关系、自旋量子数关系、自旋与同位旋量子数关系，推导并讨论了基本粒子反应中量子数变化规律     

用计算平均值的方法导出自旋

用计算平均值的方法导出自旋李光惠（襄阳师范专科学校物理学系，湖北襄樊４４１０５３；作者，男，５４岁，副教授）乌仑贝克和哥德斯密特为了解释碱金属原子光谱的精细结构和斯特恩一盖拉赫实验，提出·了电子具有自旋的假设；后来，在狄拉克建立的相对论运动方程中，顺...     

Statistical theory in clustering

A number of statistical models for forming and evaluating clusters are reviewed. Hierarchical algorithms are evaluated by their ability to discover high density regions in a population, and complete linkage hopelessly fails; the others don't do too well either. Single linkage is at least of mathematical interest because it is related to the minimum spanning tree and percolation. Mixture methods are examined, related to k-means, and the failure of likelihood tests for the number of components is noted. The DIP test for estimating the number of modes in a univariate population measures the distance between the empirical distribution function and the closest unimodal distribution function (or k-modal distribution function when testing for k modes). Its properties are examined and multivariate extensions are proposed. Ultrametric and evolutionary distances on trees are considered briefly.Research supported by the National Science Foundation Grant No. MCS-8102280.     

混合自旋(S=1,1/2)反铁磁基态能量——体心立方晶格

平行于文献[1]的做法,本文对具有混合自旋(S=1,1/2)的反铁磁体心立方晶格的基态能及相图进行了计算且进一步的证明了,用混合自旋模型(S=1,1/2)所描述的具有反铁磁相互作用的晶格即可出现亚铁磁性,也有可能出现反铁磁性。