用广角X射线衍射系列方法测试和表征高聚物各种相态的结构特征

系统地论述了广角X射线衍射系列方法 :径向分布函数、圆柱分布函数、取向分布函数、Rietveld粉末衍射全谱图最小二乘拟合、纤维全谱图精修以及衍射全谱图分峰等方法的基础理论、实验方法、计算程序及其可获得的结构参数 ;阐明采用这些方法研究高聚物非晶相、取向非晶相、结晶相的进展情况 ;探讨了联用这些方法研究高聚物二相、三相共存结构的一种新思路和新方案 ,而且已取得一定进展 ;并展望这一研究框架的全面实现 ,将能进一步拓展高聚物共混物结构的研究     

Hydrothermal-induced oriented growth of Fe–Co alloy and Sm-substituted magnetite nanowire composites

Fe–Co alloy and Sm³⁺-substituted magnetite nanowire composites (Co_xFe_1−x/Co_yFe_1−ySm_zFe_2−zO₄) have been synthesized via a hydrothermal method without using surfactants or templates. The effects of substitution on structure and morphology were investigated by powder X-ray diffraction, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, and transmission electron microscopy (TEM). The TEM image shows that the average diameter of the magnetite nanowires is about 40 nm and the length is several micrometers. The z=0.1 composite shows relatively high saturation magnetization (92.3 emu/g) detected by a vibrating sample magnetometer. The possible growth mechanism of the nanowires is discussed on the basis of the crystal structure of the materials. From the perspective of thermodynamics, we explain the postulated mechanism of the hydrothermal reaction.     

Qubits and chirotopes

We show that qubit and chirotope concepts are closely related. In fact, we prove that the qubit concept leads to a generalization of the chirotope concept, which we call qubitope. Moreover, we argue that a possible qubitope theory may suggest interesting applications of oriented matroid theory in at least three physical contexts, in which qubits make their appearance, namely string theory, black holes and quantum information.     

REAL TOMITA-TAKESAKI THEORY

Tomita-Takesaki theory in the real case is considered. The author introduces the conception of a nondegenerate pair of closed subspaces in a real Hilbert space. Then a satisfactory real Tomita-Takesaki theory is obtained, and it seems to be a special result of the complex case.