[en] Complex of UO₃xCH₃CONH₂xH₂O composition is synthesized. It is shown on the base of analysis of IR spectroscopic data that acetamide in the prepared compound is coordinated to uranium atom through oxygen. It is established by the methods of thermal analysis under poly- and isothermal conditions, X-ray phase, chemical analyses and IR spectroscopy that UO₃xCH₃CONH₂xH₂O decomposes during heating in two stages with UO₂(OH)(CH₃COO) formation (483 K in vacuum 2x10^-2 torr and 495 K in the nitrogen flow and in the air) at the first stage and UO₃ (in the air, 580 K), U₃O₈ (in the nitrogen flow, 560 K), UOsub(2.25) (vacuum 2x10^-2 torr, 553 K) at the second one

[en] An algorithm of non-reference method of fundamental parameters and the corresponding software (FUNDUK program) to analyze samples, consisting of elements with atomic num,ber Z≥11, by an X-ray spectrometer with wave dispersion in the process of excitation by an X-ray tube radiation, was described. The method is realized using the VRA-30 scanning X-ray fluorescence spectrometer, the software is written in the FORTRAN language. 7 refs

[en] Short note

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[en] Complexes of uranyl propionate with dimethyl formamide UO₂Prop₂xDMFA, dimethyl acetamide UO₂Prop₂xDMAA and tetramethylurea UO₂ Prop₂xTMU, which have not been previously described, are synthesized. The compounds are characterized by the data of element and X-ray phase analyses, IR and Raman spectroscopy. In poly-, quasiiso- and isothermal conditions the process of thermal decomposition of the complexes synthesized is studied. Stages and compositions of intermediate and final (solid and gaseous) products of thermolysis are determined. The character of ligand coordination and structure of uranyl propionate complexes with amides, as well as the effect of additional neutral ligand on way of uranyl carboxylate thermal decomposition are discussed

[en] Thermal decomposition of V(HCOO)₄ in air, in an inert atmosphere and in vacuo has been investigated by thermal analysis, infrared spectroscopy, X-ray phase analysis, differential scanning calorimetry, chromatography. VO₃ which transforms into V₃O₈ above 820 deg C, is a solid product of decomposition in air (approximately 600 K). Heating in an inert medium and in vacuo (520-550 K) leads to formation of uranium dioxide with highly developed surface (4.8x10⁴ m²/mole). The enthalpy of decomposition in argon is equal to 88.3+-5.1 kJ/mole. In the gas phase, HCOOH, CO, CO₂ and H₂ are detected which ratios depend on the transformation degree of the substance under investigation. A probable mechanism of the process is discussed

[en] The effect of introduction into the uranium coordination sphere of additional neutral nitrogen-containing ligand on the mechanism of thermolysis of uranium carboxylates is investigated. With this purpose, complexes of dioxouranium (6) formiate with formamides, carbamides and tetramethylurea are synthesized for the first time. In all the cases, the composition of synthesized complexes corresponds to the following formula: UO₂(HCOO)₂x2L, where L=-CO(NH₂)₂, HCONH₂, CO[N(CH₃)₂]₂. At the first thermolysis stages under isothermal conditions (vacuum of 10^-2 torr), desolvation processes correspond to analogous reactions in the air and in nitrogen; and the final solid product is hyperstoichiometric uranium dioxide UOsub(2+x) with various degrees of deviation from stoichiometry. It is shown that there is a principled possibility of controlling the processes of thermal decomposition of dioxouranium (6) carboxylates with the aim of preparing oxides with a given composition (which is important, for example, for the synthesis of catalysts) by introducing this or that neutral ligand into a molecule of dioxouranium (6) carboxylates

[en] The UO₂(HCOO)₂x2HCONH₂ complex is synthesized. The compound prepared is investigated using the methods of chemical, X-ray phase and thermal analyses. IR spectroscopy and mass spectrometry. The complex is indexed in the rhombic crystal system with the following parameters: a=14.39; b=13.52; c=10.71 A. The process of thermal decomposition of formamide complex of dioxouranium (6) formate (poly-, isothermal, quasiisothermal conditions in the air, nitrogen and vacuum - 1x10^-2 torr) is investigated. It is established that the compound decomposes through two stages with a successive formation of UO₂(HCOO)₂xHCONH₂ and UO₃ (air) or U₃O₈ (nitrogen), or UOsub(2+x) (0.1< x<0.15) (vacuum) as solid products. Using the experimental data obtained the structure and the possible mechanism of thermolysis of the complex synthesized are discussed

[en] Results of investigation of microelement composition of hair for different age and professional groups of population, working at enterprises involved in melting and reprocessing of metals and other chemical substances and living in the vicinity of the pollution sources are presented. Microelement composition of hair is determined by neutron activation method and method of atomic absorption. More than 3000 samples were analyzed. Prior to the analysis the samples were treated by detergent (sodium lauryl sulfate). 2 tabs