Journal of Materials Science
The chemical states of oxygen implanted in SUS304 stainless steel and pure metals (Fe,Ni,Cr) by O-2(+) ion bombardment have been investigated by means of X-ray photoelectron spectroscopy (XPS) using synchrotron soft X-ray. For SUS304, all of implanted oxygen is chemically combined with the constituent metals, forming metallic oxides. For pure metals, on the other hand, only a part of implanted oxygen react with the target metals. The other part of the implanted oxygen in pure metals does not react with the target, and they are inserted into the crystal lattice (we call them as "dissolved oxygen"). The ratio of "dissolved oxygen" to the reacted oxygen depends on the chemical reactivity of target metals. (C) 2000 Kluwer Academic Publishers.
关键词:
ions
Physica Status Solidi B-Basic Research
The high-order perturbation formulas of zero-field splitting D and gyromagnetic factors g(parallel to) and g(perpendicular to) for 3d(3) ions in tetragonal symmetry are established by using a two-spin-orbit(SO)-parameter model where the contributions to these EPR parameters from both the SO coupling of the central 3d(3) ions and that of the ligands are considered. From these formulas, the local structural parameters for the tetragonal V2+-V-M centers in MCl:V2+ (M = Na, K, Rb) crystals are estimated from the EPR data. The results are compared with those obtained from the conventional one-SO-parameter model where only the contribution of the SO coupling of central 3d(3) ions is included. The reasonableness of the results based on the two-SO-parameter model is discussed.
关键词:
ions
Journal of Physics-Condensed Matter
Detailed theoretical studies of the temperature dependence of EPR g-factor for the MgO:Cr3+ crystal have been made by considering both the static contribution due to the thermal expansion of crystal and the vibrational contributions due to the electron-phonon (including the acoustic and optical phonons) interaction. The static contribution is calculated from the macroscopic thermodynamic method and the microscopic crystal-field method. The results from both methods are close to each other, suggesting that the two methods are applicable to studies of temperature dependence of the g-factor. The vibrational contribution due to acoustic phonons is obtained by using a Debye model for the lattice vibrations, and that due to optical phonons is calculated by use of a single-frequency model. The calculated results show that, for the g(T)-factors at various temperatures, the static contribution is dominant; however, for the temperature dependence of the g-factor, i.e. dg/dT, the vibrational contributions are large and should be taken into account.
关键词:
ions
李照
,
马会民
影像科学与光化学
doi:10.7517/j.issn.1674-0475.2014.01.060
光学探针是指与目标物质发生反应(包括配位、包合和基团反应等)并引起光学(吸光、荧光或发光)性质的变化,基于这些变化从而可对目标物质进行分析与测定的一类特殊试剂.光学探针不仅能改善分析的灵敏度,而且能大幅度提高对样品的时空分辨能力,因此,长期以来一直受到人们的关注.试卤灵为一性能优良的荧光体,特别是其7-羟基的取代作用通常会封闭光信号;这一特性近年引起了人们的兴趣,并被广泛用于构建具有低背景光信号的新型探针.本文将综述试卤灵类光学探针的发展及其在蛋白酶、离子、活性氧物种分析方面的应用,包括探针分子的构筑、检测机理以及生物成像等方面的研究.
关键词:
光学探针
,
试卤灵
,
蛋白酶
,
离子
,
活性氧物种
,
荧光成像分析
