ABSTRACT
Oxidized fullerite was obtained by heating a fullerite sample intercalated with oxygen, (O2)0.44C60, up to 300 degrees C. Orientational phase transitions in the oxidized fullerite are studied using differential scanning calorimetry (DSC) and have been found to possess a specific enthalpy whose value is lower by 25% than in the initial (O2)0.44C60 sample. In order to find possible reasons for hindrance to the buckyball rotations, we performed optimizations of defect buckyball fullerenes C60-n with different distributions of vacancies along with the dimers C60-n-C60-n and C60-C60-n for n = 1-4 using density functional theory with generalized gradient approximation. We found that the dimerization energy ranges from 1.07 eV (C58-C58) to 6.56 eV (C56-C56) and from 1.81 eV (C60-C58) to 4.29 eV (C60-C56), respectively. The formation of such dimers, which could in addition interact with defect buckyball cages and form larger aggregates, is to be related to the lowering of the orientational transition enthalpy.
Subject(s)
Fullerenes/chemistry , Models, Chemical , Nanostructures/chemistry , Nanostructures/ultrastructure , Computer Simulation , Dimerization , Materials Testing , Oxidation-Reduction , Phase TransitionSubject(s)
Color Perception Tests/methods , Military Personnel , Color Vision Defects/diagnosis , Humans , RussiaABSTRACT
In Regulations about military medical examination the medical essence of fitness categories for the military service in peace and wartime, which were determined by Russian Federation law, have been worked out. The Regulations determine the most important legal norms of organization and conducting of military medical examination. List of diseases--the main functional part of Regulations--contains 89 articles (in previous--116) and 4 columns, which envisage the requirements to health state of the different categories of citizens. The article' names in List of diseases and there sequence are been adapted at most to International Disease Classification.
