scholarly journals Поведение доноров фосфора в объемных монокристаллических моноизотопных сплавах -=SUP=-28-=/SUP=-Si-=SUB=-1-x-=/SUB=--=SUP=-72-=/SUP=-Ge-=SUB=-x-=/SUB=-

2020 ◽  
Vol 54 (9) ◽  
pp. 933
Author(s):  
А.А. Ежевский ◽  
П.Г. Сенников ◽  
Д.В. Гусейнов ◽  
А.В. Сухоруков ◽  
Е.А. Калинина ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Resonance Method ◽  
Relaxation Mechanism ◽  
Longitudinal Component ◽  
Bulk Single Crystal ◽  
Orbit Splitting ◽  
Spin Resonance ◽  
Temperature Dependences ◽  
Silicon And Germanium

Abstract The behavior of phosphorus donors in bulk single-crystal monoisotopic Si_1 – _ x Ge_ x alloys ( x = 0.0039–0.05) enriched by zero-spin isotopes ^28Si (99.998%) and ^72Ge (99.984%) by the electron-spin-resonance method is investigated. The hyperfine structure of the donor-electron spectrum giving information on the density of the donor wave function in the ground state on the ^31P nucleus ( I = 1/2) as well as the temperature dependences of the spin-relaxation rate ( T = 3.5–30 K), which make it possible to analyze the longitudinal component T _1 relaxation mechanism and magnitude of the valley–orbit splitting of the donor state, are investigated. Interest in these investigations is also caused by the fact that the Si_1 – _ x Ge_ x alloy enriched by zero-spin isotopes (^28Si^isoGe, iso = 70, 72, 74, 76) is a poorly known material when compared with ^28Si. The irregular arrangement of germanium atoms in the lattice of the SiGe solid solution and local distortions formed by it can level isotopic effects under isotopic enrichment. However, despite broadening of the lines of the electron-spin resonance of donor electrons due to random deformations formed by dissolved germanium atoms in silicon, narrower lines of the spectra of the electron-spin resonance are observed in isotopically pure Si_1 – _ x Ge_ x single crystals at x = 0.39, 1.2, 2.9 at % when compared with similar crystals with the natural composition of silicon and germanium isotopes.

Radiation damage in polyethylene as studied by electron spin resonance

1961 ◽  
Vol 262 (1309) ◽  
pp. 207-218 ◽  
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Alkyl Radical ◽  
Room Temperature ◽  
Chemical Properties ◽  
Resonance Method ◽  
Alkyl Radicals ◽  
Spin Resonance ◽  
Physical And Chemical ◽  
Kinetics Of

The electron spin resonance method was employed to study the nature, concentration and kinetics of the disappearance under varying conditions of radicals produced in polyethylene by fast electron irradiation at 77°K. The predominant radical species at 77°K is the alkyl radical —CH 2 —ĊH—CH 2 —. On being warmed to room temperature it disappears rapidly, revealing a more stable un­identified radical. The kinetics of the decay at room temperature of both radicals was observed. Their stabilities were found to vary in polyethylene samples of differing physical and chemical properties. G values for these radicals are given. Comparison was made with spectra obtained under similar conditions with two pure paraffins and a pure olefin to evaluate the effect of crystallinity branching, molecular weight and unsaturation. In the olefin there is evidence for a build-up of allyl radicals due to the encounter of an alkyl radical with main chain unsaturation. This supports the view that alkyl radicals are mobile, and cross-linking occurs when two such radicals meet.

scholarly journals Roles of Adiponectin and Oxidative Stress in the Regulation of Membrane Microviscosity of Red Blood Cells in Hypertensive Men—An Electron Spin Resonance Study

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Kazushi Tsuda
Keyword(s):  
Oxidative Stress ◽  
Electron Spin Resonance ◽  
Membrane Fluidity ◽  
Electron Spin ◽  
Order Parameter ◽  
Resonance Method ◽  
Electron Spin Resonance Study ◽  
Plasma Adiponectin ◽  
Spin Resonance ◽  
And Oxidative Stress

This study was undertaken to investigate possible relationships among plasma adiponectin, 8-iso-prostaglandin F2α(8-iso-PG F2α: an index of oxidative stress), and membrane fluidity (a reciprocal value of microviscosity) in hypertensive and normotensive men using an electron spin resonance-method. The order parameter (S) for the spin-label agent (5-nitroxide stearate) in red blood cell (RBC) membranes was higher in hypertensive men than in normotensive men, indicating that membrane fluidity was decreased in hypertension. Plasma adiponectin and NO metabolites levels were lower in hypertensive men than in normotensive men. In contrast, plasma 8-iso-PG F2αlevels were increased in hypertensive men compared with normotensive men. Plasma adiponectin concentration was correlated with plasma NO-metabolites, and inversely correlated with plasma 8-iso-PG F2α. The order parameter (S) of RBCs was inversely correlated with plasma adiponectin and plasma NO metabolite levels, and positively correlated with plasma 8-iso-PG F2α, suggesting that the reduced membrane fluidity of RBCs might be associated with hypoadiponectinemia, endothelial dysfunction, and increased oxidative stress. In a multivariate regression analysis, adiponectin and 8-iso-PG F2αwere significant determinants of membrane fluidity of RBCs after adjustment for general risk factors. These results suggest that adiponectin and oxidative stress might have a close correlation with rheologic behavior and microcirculation in hypertension.

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