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The model experiments regarding the conversion of organic matters from carbonate rock samples of Dankov-Lebedyan deposits of Zelenogorskaya area and siliceous-carbonate rocks of Semiluki-Mendym deposits of Berezovskaya area of Domanic formations of Romashkino oil field were carried out. Two types of experiments were carried out: (1) the hydrothermal treatment of rocks at a temperature of 350°C in the presence of carbonic acid and a water content of 30%; (2) pyrolysis at temperatures of 350 and 600°C in the presence of hydrogen. The yield and quality of extracted hydrocarbons from the rocks depending on the mineral composition of rocks, content and composition of organic matter, and thermal stability of kerogen under hydrothermal influences were evaluated. Application of electron paramagnetic resonance in pyrolysis processes revealed the difference in mineral content of rocks (Mn2+, SO3−, and SO2− ions) and free radicals R∗, as well as in vanadyl ion (VO2+) concentration. It is established that an increasing temperature of pyrolysis promotes the formation of new free organic radicals in rock samples: in Domanic rocks of Semiluki-Mendym deposits at 350°С and in carbonate rocks of Dankov-Lebedyan horizon at 600°С. This indicates different ability of oil-generating potential of rocks with hydrothermal and pyrolysis technologies.

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The transformation of the organic matter (OM) of low-permeable carbon-rich domanik rock of the Romashkino oilfield in sub-and supercritical water (SCW) at temperatures of 320, 374, and 420°C and pressures of 17, 24.6, and 24.4 MPa in a neutral medium has been studied. The original rock with a TOC content of 7% has a high oil generation potential and a low productivity index. The productivity index increases with an increase in the severity of the thermal treatment of the rock, which is due to intense kerogen degradation resulting in the formation of free hydrocarbons that are easy to recover from the rock. In rock extracts, in comparison with the original rock, the amount of saturated and aromatic hydrocarbons increases by more than two times and that of resin-asphaltene substances decreases. Distinctive features of the yields and compositions of rock extracts depending on the temperature of the experiments have been revealed. The highest yield of the extract was observed in the experiment with subcritical water at 320°C and associated with the degradation of resins and more complete extraction of asphaltenes and high-molecular-weight n-alkanes from the rock. Treatment in SCW at 374 and 420°C leads to intensive degradation of the kerogen structure involving the detachment of aliphatic chains from large fragments of kerogen and asphaltene macromolecules to form lower n-alkanes and carbon-rich substances, such as carbenes and carboids. The structure of asphaltenes becomes more condensed and oxidized in the SCW medium at 420°С, leading to a decrease in their paramagnetic properties. Using the EPR technique, the features of hyperfine splitting of the vanadyl complex line on 14 N nitrogen nuclei have been revealed in the spectrum of asphaltenes of the SCW experiment at 420°С, indicating specific changes in their structure.

Dopant Fe 3 t ions in tetrahedral and octahedral positions of Ge 4 I in the crystal Li,GePI5 were studied using EPR. Fe H substitutes for Gc 4 + with a local charge compensation. The octahedral site and the tetrahedral sites significantly differ by the value of the invariant sum S(B 4 ) of the B 4 tensor of the spin Hamiltonian of Fe H . The irreducible tensor products {V 4®V4 } 4 and {V 4®V4 } , of the V 4 tensor of the crystal field calculated using the point-charge model for octahedral and tetrahedral complexes provide the predominant contribution of the crystal field to the B 4 and B, tensors of the spin Hamiltonian of Fe H , respectively. A comparison of the fourth-rank tensors B 4 of the spin Hamiltonian and {V 4 ® V 4 } 4 of the crystal field determined at 300 K with those determined at 77 K supports the conclusion that the phase transition is accompanied by combined rotations of the [Ge0 41 tetrahedra with the [Ge(l)061 octahedron almost unaltered. The spectrum lines are narrow and the variety of point defects in the vicinity of the paramagnetic impurity ions Fe H , Cr 3 + and Cu" is not detected. These facts are inconsistent with the statistically distributed model for the Li(2) atom. In specific cases at 300 K, when the wings of the two spectrum lines of the M -M+ I and the M+ 2 -M+ 3 transitions of Fe H ions belonging to one system of translationally equivalent positions overlap an extra line appears in the center between these lines. It is suggested that this effect is due to the soft phonon mode above the phase transition temperature.

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Noble metal-free heterogeneous catalysts are highly desired for selective and solvent-free oxidation reactions. However, their practical application has been greatly restricted by their moderate activity.

Abstraet. In single crystal colquiriite LiCaA1F 6 doped with Gd 3+ ions two EPR speetra of the Gd 3+ ions with the Laue site-symmetry groups C i and C3i were observed. The spectrum angular dependente for trigonal Gd 3+ centre was investigated in detail and corresponding spin Hamiltonian parameters were fitted. From analysis of the spin Hamiltonian tensors B 4 and B 6 it was established that Gd 3 § with the Laue group C3~ substitutes at Ca 2 § site with the excess charge compensation by an ion located along the threefold axis from this site. The transformation formulas for a sixth-rank irreducible Hermitian tensor under coordinate rotation are tabulated in an explicit form. By using the EPR data for Gd 3~ substituted in a variety of host crystals, the fourth-rank and sixth-rank tensors of Gd 3+ spin Hamiltonians were tabulated and correlated with structures of the coordination polyhedra al substitution sites. The results suppose a predominante of quadratic crystal field contributions into the spin Hamiltonian tensor B 4 of Gd 3+.