Salt formation by reaction of fluorine-containing β-diketones with amines

Conclusions Polyfluorinated-diketones form stable salts with ammonia and amines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 623–627, March, 1984.     

Interaction of trichloromethane and tetrachloromethane with nitrogen trifluoride

Interaction of nitrogen trifluoride with trichloromethane and tetrachloromethane at temperatures in the range from 20 to 200°C and pressures of up to 6.0 MPa in the gas and liquid phases was studied.     

Magnetic and transport properties of Gd0.9A0.1CoO3−δ (A=Ba, Sr)

The X-ray diffraction, magnetization and electrical conductivity measurements for Gd_0.9A_0.1CoO_3−δ (A=Ba, Sr) have been made. The complicated magnetic behavior, including the paramagnetic-ferromagnetic-antiferromagnetic and paramagnetic-ferromagnetic transitions, was found for Ba- and Sr-doped samples. The gradual insulator-metal transitions were observed in a wide temperature range T=600−800 K. The complex magnetic and transport data could be explained on the basis of the structural phase separation.     

Investigation of the 208Pb(18O, f) fission reaction: Mass-energy distributions of fission fragments and their correlation with the gamma-ray multiplicity

The mass-energy distributions of fragments originating from the fission of the compound nucleus ²²⁶Th and their correlations with the multiplicity of gamma rays emitted from these fragments are measured and analyzed in ¹⁸O + ²⁰⁸Pb interaction induced by projectile oxygen ions of energy in the range E _lab = 78–198.5 MeV. Manifestations of an asymmetric fission mode, which is damped exponentially with increasing E _lab, are demonstrated. Theoretical calculations of fission valleys reveal that only two independent valleys, symmetric and asymmetric, exist in the vicinity of the scission point. The dependence of the multiplicity of gamma rays emitted from both fission fragments on their mass, M_γ(M), has a complicated structure and is highly sensitive to shell effects in both primary and final fragments. A two-component analysis of the dependence M_γ(M) shows that the asymmetric mode survives in fission only at low partial-wave orbital angular momenta of compound nuclei. It is found that, for all E _lab, the gamma-ray multiplicity M_γ as a function of the total kinetic energy (TKE) of fragments, M_γ(TKE), decreases linearly with increasing TKE. An analysis of the energy balance in the fission process at the laboratory energy of E _lab = 78 MeV revealed the region of cold fission of fragments whose total kinetic energy is TKE ～Q _max.     

The Th fission valleys

One of the interesting problems in the nuclear fission studies is the nature of the asymmetry of the fission fragment mass distribution (FFMD). In connection with recent experiments, the valleys on the potential energy surface of ²²⁶Th have been considered. The pre-scission nuclear shape calculated as a result of the minimization in multi-dimensional space of the deformation parameters with two constrains is shown to be of the type considered by Brosa et al.     

Synthesis of 3-fluoroalkyl-2-aziridinyl ketones

Simple and efficient methods for the synthesis oftrans-3-fluoroalkyl-2-aziridinyl ketones from polyfluorinated α,β-enones have been developed.     

2,4-Bridged 1,5-bis(fluoroalkyl)-1,3,5-triketones: synthesis and properties

Symmetrical and unsymmetrical bis-fluoroacylcyclopentanones and cyclohexanones were synthesized. NMR data reveal that the keto-enol tautomeric equilibrium is changed markedly by the presence of a trimethylene bridge compared to an ethylene moiety. A considerable influence of the fluoroalkyl chain length was found for 2,6-(bisfluoroacyl)cyclohexanones.     

Excitation effects on the nuclear-fission process in the heaviest elements

Calculations have been carried out of the fission barriers of excited nuclei for elements with Z = 102?108. The effect of nuclear heating is taken into account according to conventional quantum-statistical formulae. A realistic Woods-Saxon potential is employed to calculate single particle states. The- degree of deviation of the fissioning nucleus shape from axial symmetry and changes in the depth of the intermediate minimum are discussed.